Programs & Examples On #Accessible

The degree to which a product, device, service, or environment is available to as many people as possible.

How to make a variable accessible outside a function?

Your variable declarations and their scope are correct. The problem you are facing is that the first AJAX request may take a little bit time to finish. Therefore, the second URL will be filled with the value of sID before the its content has been set. You have to remember that AJAX request are normally asynchronous, i.e. the code execution goes on while the data is being fetched in the background.

You have to nest the requests:

$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   obj = name;   // sID is only now available!   sID = obj.id;   console.log(sID); }); 


Clean up your code!

  • Put the second request into a function
  • and let it accept sID as a parameter, so you don't have to declare it globally anymore! (Global variables are almost always evil!)
  • Remove sID and obj variables - name.id is sufficient unless you really need the other variables outside the function.


$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   // We don't need sID or obj here - name.id is sufficient   console.log(name.id);    doSecondRequest(name.id); });  /// TODO Choose a better name function doSecondRequest(sID) {   $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function(stats){         console.log(stats);   }); } 

Hapy New Year :)

Where to declare variable in react js

Using ES6 syntax in React does not bind this to user-defined functions however it will bind this to the component lifecycle methods.

So the function that you declared will not have the same context as the class and trying to access this will not give you what you are expecting.

For getting the context of class you have to bind the context of class to the function or use arrow functions.

Method 1 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.onMove = this.onMove.bind(this);
        this.testVarible= "this is a test";
    }

    onMove() {
        console.log(this.testVarible);
    }
}

Method 2 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.testVarible= "this is a test";
    }

    onMove = () => {
        console.log(this.testVarible);
    }
}

Method 2 is my preferred way but you are free to choose your own.

Update: You can also create the properties on class without constructor:

class MyContainer extends Component {

    testVarible= "this is a test";

    onMove = () => {
        console.log(this.testVarible);
    }
}

Note If you want to update the view as well, you should use state and setState method when you set or change the value.

Example:

class MyContainer extends Component {

    state = { testVarible: "this is a test" };

    onMove = () => {
        console.log(this.state.testVarible);
        this.setState({ testVarible: "new value" });
    }
}

groovy.lang.MissingPropertyException: No such property: jenkins for class: groovy.lang.Binding

As pointed out by @Jayan in another post, the solution was to do the following

import jenkins.model.*
jenkins = Jenkins.instance

Then I was able to do the rest of my scripting the way it was.

React Router Pass Param to Component

try this.

<Route exact path="/details/:id" render={(props)=>{return(
    <DetailsPage id={props.match.params.id}/>)
}} />

In details page try this...

this.props.id

How to get root directory of project in asp.net core. Directory.GetCurrentDirectory() doesn't seem to work correctly on a mac

It seems IHostingEnvironment has been replaced by IHostEnvironment (and a few others). You should be able to change the interface type in your code and everything will work as it used to :-)

You can find more information about the changes at this link on GitHub https://github.com/aspnet/AspNetCore/issues/7749

EDIT There is also an additional interface IWebHostEnvironment that can be used in ASP.NET Core applications. This is available in the Microsoft.AspNetCore.Hosting namespace.

Ref: https://stackoverflow.com/a/55602187/932448

Vue.js: Conditional class style binding

Use the object syntax.

v-bind:class="{'fa-checkbox-marked': content['cravings'],  'fa-checkbox-blank-outline': !content['cravings']}"

When the object gets more complicated, extract it into a method.

v-bind:class="getClass()"

methods:{
    getClass(){
        return {
            'fa-checkbox-marked': this.content['cravings'],  
            'fa-checkbox-blank-outline': !this.content['cravings']}
    }
}

Finally, you could make this work for any content property like this.

v-bind:class="getClass('cravings')"

methods:{
  getClass(property){
    return {
      'fa-checkbox-marked': this.content[property],
      'fa-checkbox-blank-outline': !this.content[property]
    }
  }
}

Can Keras with Tensorflow backend be forced to use CPU or GPU at will?

A rather separable way of doing this is to use

import tensorflow as tf
from keras import backend as K

num_cores = 4

if GPU:
    num_GPU = 1
    num_CPU = 1
if CPU:
    num_CPU = 1
    num_GPU = 0

config = tf.ConfigProto(intra_op_parallelism_threads=num_cores,
                        inter_op_parallelism_threads=num_cores, 
                        allow_soft_placement=True,
                        device_count = {'CPU' : num_CPU,
                                        'GPU' : num_GPU}
                       )

session = tf.Session(config=config)
K.set_session(session)

Here, with booleans GPU and CPU, we indicate whether we would like to run our code with the GPU or CPU by rigidly defining the number of GPUs and CPUs the Tensorflow session is allowed to access. The variables num_GPU and num_CPU define this value. num_cores then sets the number of CPU cores available for usage via intra_op_parallelism_threads and inter_op_parallelism_threads.

The intra_op_parallelism_threads variable dictates the number of threads a parallel operation in a single node in the computation graph is allowed to use (intra). While the inter_ops_parallelism_threads variable defines the number of threads accessible for parallel operations across the nodes of the computation graph (inter).

allow_soft_placement allows for operations to be run on the CPU if any of the following criterion are met:

  1. there is no GPU implementation for the operation

  2. there are no GPU devices known or registered

  3. there is a need to co-locate with other inputs from the CPU

All of this is executed in the constructor of my class before any other operations, and is completely separable from any model or other code I use.

Note: This requires tensorflow-gpu and cuda/cudnn to be installed because the option is given to use a GPU.

Refs:

Reload child component when variables on parent component changes. Angular2

You can use @input with ngOnChanges, to see the changes when it happened.

reference: https://angular.io/api/core/OnChanges

(or)

If you want to pass data between multiple component or routes then go with Rxjs way.

Service.ts

import { Injectable } from '@angular/core';
import { Observable, Subject } from 'rxjs';

@Injectable({ providedIn: 'root' })
export class MessageService {
  private subject = new Subject<any>();

  sendMessage(message: string) {
    this.subject.next({ text: message });
  }

  clearMessages() {
    this.subject.next();
  }

  getMessage(): Observable<any> {
    return this.subject.asObservable();
  }
}

Component.ts

import { Component, OnDestroy } from '@angular/core';
import { Subscription } from 'rxjs';

import { MessageService } from './_services/index';

@Component({
  selector: 'app',
  templateUrl: 'app.component.html'
})

export class AppComponent implements OnDestroy {
  messages: any[] = [];
  subscription: Subscription;

  constructor(private messageService: MessageService) {
    // subscribe to home component messages
    this.subscription = this.messageService.getMessage().subscribe(message => {
      if (message) {
        this.messages.push(message);
      } else {
        // clear messages when empty message received
        this.messages = [];
      }
    });
  }

  ngOnDestroy() {
    // unsubscribe to ensure no memory leaks
    this.subscription.unsubscribe();
  }
}

Reference: http://jasonwatmore.com/post/2019/02/07/angular-7-communicating-between-components-with-observable-subject

Token based authentication in Web API without any user interface

ASP.Net Web API has Authorization Server build-in already. You can see it inside Startup.cs when you create a new ASP.Net Web Application with Web API template.

OAuthOptions = new OAuthAuthorizationServerOptions
{
    TokenEndpointPath = new PathString("/Token"),
    Provider = new ApplicationOAuthProvider(PublicClientId),
    AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
    AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
    // In production mode set AllowInsecureHttp = false
    AllowInsecureHttp = true
};

All you have to do is to post URL encoded username and password inside query string.

/Token/userName=johndoe%40example.com&password=1234&grant_type=password

If you want to know more detail, you can watch User Registration and Login - Angular Front to Back with Web API by Deborah Kurata.

Access Tomcat Manager App from different host

For Tomcat v8.5.4 and above, the file <tomcat>/webapps/manager/META-INF/context.xml has been adjusted:

<Context antiResourceLocking="false" privileged="true" >
    <Valve className="org.apache.catalina.valves.RemoteAddrValve"
         allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />
</Context>

Change this file to comment the Valve:

<Context antiResourceLocking="false" privileged="true" >
    <!--
    <Valve className="org.apache.catalina.valves.RemoteAddrValve"
         allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />
    -->
</Context>

After that, refresh your browser (not need to restart Tomcat), you can see the manager page.

Delete an element in a JSON object

with open('writing_file.json', 'w') as w:
    with open('reading_file.json', 'r') as r:
        for line in r:
            element = json.loads(line.strip())
            if 'hours' in element:
                del element['hours']
            w.write(json.dumps(element))

this is the method i use..

How can I declare a global variable in Angular 2 / Typescript?

I think the best way is to share an object with global variables throughout your application by exporting and importing it where you want.

First create a new .ts file for example globals.ts and declare an object. I gave it an Object type but you also could use an any type or {}

export let globalVariables: Object = {
 version: '1.3.3.7',
 author: '0x1ad2',
 everything: 42
};

After that import it

import {globalVariables} from "path/to/your/globals.ts"

And use it

console.log(globalVariables);

How to make the webpack dev server run on port 80 and on 0.0.0.0 to make it publicly accessible?

For me: changing the listen host worked:

.listen(3000, 'localhost', function (err, result) {
        if (err) {
            console.log(err);
        }
        console.log('Listening at localhost:3000');
    });

was changed to :

.listen(3000, '0.0.0.0', function (err, result) {
        if (err) {
            console.log(err);
        }
        console.log('Listening at localhost:3000');
    });

and the server started listening on 0.0.0.0

How to set base url for rest in spring boot?

I found a clean solution, which affects only rest controllers.

@SpringBootApplication
public class WebApp extends SpringBootServletInitializer {

    @Autowired
    private ApplicationContext context;

    @Bean
    public ServletRegistrationBean restApi() {
        XmlWebApplicationContext applicationContext = new XmlWebApplicationContext();
        applicationContext.setParent(context);
        applicationContext.setConfigLocation("classpath:/META-INF/rest.xml");

        DispatcherServlet dispatcherServlet = new DispatcherServlet();
        dispatcherServlet.setApplicationContext(applicationContext);

        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(dispatcherServlet, "/rest/*");
        servletRegistrationBean.setName("restApi");

        return servletRegistrationBean;
    }

    static public void main(String[] args) throws Exception {
        SpringApplication.run(WebApp.class,args);
    }
}

Spring boot will register two dispatcher servlets - default dispatcherServlet for controllers, and restApi dispatcher for @RestControllers defined in rest.xml:

2016-06-07 09:06:16.205  INFO 17270 --- [           main] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'restApi' to [/rest/*]
2016-06-07 09:06:16.206  INFO 17270 --- [           main] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]

The example rest.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="
  http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
  http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
  http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan base-package="org.example.web.rest"/>
    <mvc:annotation-driven/>

    <!-- Configure to plugin JSON as request and response in method handler -->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="jsonMessageConverter"/>
            </list>
        </property>
    </bean>

    <!-- Configure bean to convert JSON to POJO and vice versa -->
    <bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    </bean>
</beans>

But, you're not limited to:

  • use XmlWebApplicationContext, you may use any else context type available, ie. AnnotationConfigWebApplicationContext, GenericWebApplicationContext, GroovyWebApplicationContext, ...
  • define jsonMessageConverter, messageConverters beans in rest context, they may be defined in parent context

How to add LocalDB to Visual Studio 2015 Community's SQL Server Object Explorer?

I had the same issue today recently installing VS2015 Community Edition Update 1.

I fixed the problem by just adding the "SQL Server Data Tools" from the VS2015 setup installer... When I ran the installer the first time I selected the "Custom" installation type instead of the "Default". I wanted to see what install options were available but not select anything different than what was already ticked. My assumption was that whatever was already ticked was essentially the default install. But its not.

Ubuntu: Using curl to download an image

For those who don't have nor want to install wget, curl -O (capital "o", not a zero) will do the same thing as wget. E.g. my old netbook doesn't have wget, and is a 2.68 MB install that I don't need.

curl -O https://www.python.org/static/apple-touch-icon-144x144-precomposed.png

Error resolving template "index", template might not exist or might not be accessible by any of the configured Template Resolvers

Check for the name of the

templates

folder. it should be templates not template(without s).

How can I share Jupyter notebooks with non-programmers?

Michael's suggestion of running your own nbviewer instance is a good one I used in the past with an Enterprise Github server.

Another lightweight alternative is to have a cell at the end of your notebook that does a shell call to nbconvert so that it's automatically refreshed after running the whole thing:

!ipython nbconvert <notebook name>.ipynb --to html

EDIT: With Jupyter/IPython's Big Split, you'll probably want to change this to !jupyter nbconvert <notebook name>.ipynb --to html now.

Python: Importing urllib.quote

Use six:

from six.moves.urllib.parse import quote

six will simplify compatibility problems between Python 2 and Python 3, such as different import paths.

How to install requests module in Python 3.4, instead of 2.7

On Windows with Python v3.6.5

py -m pip install requests

Where to put the gradle.properties file

Actually there are 3 places where gradle.properties can be placed:

  1. Under gradle user home directory defined by the GRADLE_USER_HOME environment variable, which if not set defaults to USER_HOME/.gradle
  2. The sub-project directory (myProject2 in your case)
  3. The root project directory (under myProject)

Gradle looks for gradle.properties in all these places while giving precedence to properties definition based on the order above. So for example, for a property defined in gradle user home directory (#1) and the sub-project (#2) its value will be taken from gradle user home directory (#1).

You can find more details about it in gradle documentation here.

SSH Key: “Permissions 0644 for 'id_rsa.pub' are too open.” on mac

If the keys are in the ~/.ssh directory , use

chmod 400 ~/.ssh/id_rsa

If the keys are in different directory, use

chmod 400 directory_path/id_rsa

This worked for me.

AWS EFS vs EBS vs S3 (differences & when to use?)

I wonder why people are not highlighting the MOST compelling reason in favor of EFS. EFS can be mounted on more than one EC2 instance at the same time, enabling access to files on EFS at the same time.

(Edit 2020 May, EBS supports mounting to multiple EC2 at same time now as well, see: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html)

How to pass data to all views in Laravel 5?

1) In (app\Providers\AppServiceProvider.php)

// in boot function
       view()->composer('*', function ($view) {
            $data = User::messages();
            $view->with('var_messages',$data);
        });

2) in Your User Model

  public static function messages(){ // this is just example
        $my_id = auth()->user()->id;
        $data= Message::whereTo($my_id)->whereIs_read('0')->get(); 
        return $data; // return is required
    }

3) in Your View

 {{ $var_messages }}

TypeError: Router.use() requires middleware function but got a Object

Check your all these file:

var users = require('./routes/users');

var Users = require('./models/user');
var Items = require('./models/item');

Save properly, In my case, one file was missed and throwing the same error

variable is not declared it may be inaccessible due to its protection level

Pay close attention to the first part of the error: "variable is not declared"

Ignore the second part: "it may be inaccessible due to its protection level". It's a red herring.

Some questions... (the answers might be in that image you posted, but I can't seem to make it larger and my eyes don't read that small of print... Any chance you can post the code in a way these older eyes can read it? Makes it hard to know the total picture. In particular I am suspicious of your Page directives.)

We know that 1stReasonTypes is a listbox, but for some reason it seems like we don't know WHICH listbox. This is why I want to see your page directives.

But also, how are you calling the private method FormRefresh()? It's not an event handler, which makes me wonder if you are trying to reference a listbox in a form that is not handled properly in this code behind.

You may need to find the control 1stReasonTypes. Try maybe putting your listbox inside something like

<div id="MyFormDiv" runat="server">.....</div>

then in FormRefresh(), do a...

Dim 1stReasonTypesNew As listbox = MyFormDiv.FindControl("1stReasonTypes")

Or use an existing control, object, or page instead of a div. More info on FindControl: http://msdn.microsoft.com/en-us/library/486wc64h(v=vs.110).aspx

But no matter how you slice it, there is something funky going here such that 1stReasonTypes doesn't know which exact listbox it's supposed to be.

How to automatically import data from uploaded CSV or XLS file into Google Sheets

In case anyone would be searching - I created utility for automated import of xlsx files into google spreadsheet: xls2sheets. One can do it automatically via setting up the cronjob for ./cmd/sheets-refresh, readme describes it all. Hope that would be of use.

SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance

I usually fix this errore following this msdn blog post Using LocalDB with Full IIS

This requires editing applicationHost.config file which is usually located in C:\Windows\System32\inetsrv\config. Following the instructions from KB 2547655 we should enable both flags for Application Pool ASP.NET v4.0, like this:

<add name="ASP.NET v4.0" autoStart="true" managedRuntimeVersion="v4.0"     managedPipelineMode="Integrated">
    <processModel identityType="ApplicationPoolIdentity" loadUserProfile="true" setProfileEnvironment="true" />
</add>

SQL Server : login success but "The database [dbName] is not accessible. (ObjectExplorer)"

I just restarted my SQL Server (MSSQLSERVER) with which my SQL Server Agent (MSSQLSERVER) also got restarted. Now am able to access the SQL SERVER 2008 R2 database instance through SSMS with my login.

SQL Connection Error: System.Data.SqlClient.SqlException (0x80131904)

Check you routes, the update on 9/28/2014 impacted us. We had to adjust our older servers and add new routes. Here is the article http://www.rackspace.com/knowledge_center/article/updating-servicenet-routes-on-cloud-servers-created-before-june-3-2013

Nginx: stat() failed (13: permission denied)

This is usually the privilege problem... For me, its because i use the /root/** as the nginx root, it need higher privilege. An easy way is just move the project into a directory created by yourself.

Nginx serves .php files as downloads, instead of executing them

I had similar problem which was resolved by emptying the browser cache (also worked fine with different browser).

SQL Server Service not available in service list after installation of SQL Server Management Studio

downloaded Sql server management 2008 r2 and got it installed. Its getting installed but when I try to connect it via .\SQLEXPRESS it shows error. DO I need to install any SQL service on my system?

You installed management studio which is just a management interface to SQL Server. If you didn't (which is what it seems like) already have SQL Server installed, you'll need to install it in order to have it on your system and use it.

http://www.microsoft.com/en-us/download/details.aspx?id=1695

iOS 8 removed "minimal-ui" viewport property, are there other "soft fullscreen" solutions?

I haven't done web design for iOS but from what I recall seeing in the WWDC sessions and in documentation, the search bar in Mobile Safari, and navigation bars across the OS, will now automatically resize and shrink to show more of your content.

You can test this in Safari on an iPhone and notice that, when you scroll down to see more contents on a page, the navigation/search bar is hidden automatically.

Perhaps leaving the address bar/navigation bar as is, and not creating a full-screen experience, is what's best. I don't see Apple doing that anytime soon. And at most they are not automatically controlling when the address bar shows/hides.

Sure, you are losing screen real estate, specially on an iPhone 4 or 4S, but there doesn't seem to be an alternative as of Beta 4.

Reading in a JSON File Using Swift

Latest swift 3.0 absolutely working

func loadJson(filename fileName: String) -> [String: AnyObject]?
{
    if let url = Bundle.main.url(forResource: fileName, withExtension: "json") 
{
      if let data = NSData(contentsOf: url) {
          do {
                    let object = try JSONSerialization.jsonObject(with: data as Data, options: .allowFragments)
                    if let dictionary = object as? [String: AnyObject] {
                        return dictionary
                    }
                } catch {
                    print("Error!! Unable to parse  \(fileName).json")
                }
            }
            print("Error!! Unable to load  \(fileName).json")
        }
        return nil
    }

How to manually force a commit in a @Transactional method?

Why don't you use spring's TransactionTemplate to programmatically control transactions? You could also restructure your code so that each "transaction block" has it's own @Transactional method, but given that it's a test I would opt for programmatic control of your transactions.

Also note that the @Transactional annotation on your runnable won't work (unless you are using aspectj) as the runnables aren't managed by spring!

@RunWith(SpringJUnit4ClassRunner.class)
//other spring-test annotations; as your database context is dirty due to the committed transaction you might want to consider using @DirtiesContext
public class TransactionTemplateTest {

@Autowired
PlatformTransactionManager platformTransactionManager;

TransactionTemplate transactionTemplate;

@Before
public void setUp() throws Exception {
    transactionTemplate = new TransactionTemplate(platformTransactionManager);
}

@Test //note that there is no @Transactional configured for the method
public void test() throws InterruptedException {

    final Contract c1 = transactionTemplate.execute(new TransactionCallback<Contract>() {
        @Override
        public Contract doInTransaction(TransactionStatus status) {
            Contract c = contractDOD.getNewTransientContract(15);
            contractRepository.save(c);
            return c;
        }
    });

    ExecutorService executorService = Executors.newFixedThreadPool(5);

    for (int i = 0; i < 5; ++i) {
        executorService.execute(new Runnable() {
            @Override  //note that there is no @Transactional configured for the method
            public void run() {
                transactionTemplate.execute(new TransactionCallback<Object>() {
                    @Override
                    public Object doInTransaction(TransactionStatus status) {
                        // do whatever you want to do with c1
                        return null;
                    }
                });
            }
        });
    }

    executorService.shutdown();
    executorService.awaitTermination(10, TimeUnit.SECONDS);

    transactionTemplate.execute(new TransactionCallback<Object>() {
        @Override
        public Object doInTransaction(TransactionStatus status) {
            // validate test results in transaction
            return null;
        }
    });
}

}

Set field value with reflection

The method below sets a field on your object even if the field is in a superclass

/**
 * Sets a field value on a given object
 *
 * @param targetObject the object to set the field value on
 * @param fieldName    exact name of the field
 * @param fieldValue   value to set on the field
 * @return true if the value was successfully set, false otherwise
 */
public static boolean setField(Object targetObject, String fieldName, Object fieldValue) {
    Field field;
    try {
        field = targetObject.getClass().getDeclaredField(fieldName);
    } catch (NoSuchFieldException e) {
        field = null;
    }
    Class superClass = targetObject.getClass().getSuperclass();
    while (field == null && superClass != null) {
        try {
            field = superClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            superClass = superClass.getSuperclass();
        }
    }
    if (field == null) {
        return false;
    }
    field.setAccessible(true);
    try {
        field.set(targetObject, fieldValue);
        return true;
    } catch (IllegalAccessException e) {
        return false;
    }
}

Spring Boot - Cannot determine embedded database driver class for database type NONE

You can add

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration   

to your application.properties file.

"Sub or Function not defined" when trying to run a VBA script in Outlook

This error “Sub or Function not defined”, will come every time when there is some compile error in script, so please check syntax again of your script.

I guess that is why when you used msqbox instead of msgbox it throws the error.

AltGr key not working, instead I have to use Ctrl+AltGr

I found a solution for my problem while writing my question !

Going into my remote session i tried two key combinations, and it solved the problem on my Desktop : Alt+Enter and Ctrl+Enter (i don't know which one solved the problem though)

I tried to reproduce the problem, but i couldn't... but i'm almost sure it's one of the key combinations described in the question above (since i experienced this problem several times)

So it seems the problem comes from the use of RDP (windows7 and 8)

Update 2017: Problem occurs on Windows 10 aswell.

WAMP Cannot access on local network 403 Forbidden

If you are using WAMPServer 3 See bottom of answer

For WAMPServer versions <= 2.5

By default Wampserver comes configured as securely as it can, so Apache is set to only allow access from the machine running wamp. Afterall it is supposed to be a development server and not a live server.

Also there was a little error released with WAMPServer 2.4 where it used the old Apache 2.2 syntax instead of the new Apache 2.4 syntax for access rights.

You need to change the security setting on Apache to allow access from anywhere else, so edit your httpd.conf file.

Change this section from :

#   onlineoffline tag - don't remove
     Order Deny,Allow
     Deny from all
     Allow from 127.0.0.1
     Allow from ::1
     Allow from localhost

To :

#   onlineoffline tag - don't remove
    Require local
    Require ip 192.168.0

The Require local allows access from these ip's 127.0.0.1 & localhost & ::1.

The statement Require ip 192.168.0 will allow you to access the Apache server from any ip on your internal network. Also it will allow access using the server mechines actual ip address from the server machine, as you are trying to do.

WAMPServer 3 has a different method

In version 3 and > of WAMPServer there is a Virtual Hosts pre defined for localhost so you have to make the access privilage amendements in the Virtual Host definition config file

First dont amend the httpd.conf file at all, leave it as you found it.

Using the menus, edit the httpd-vhosts.conf file.

enter image description here

It should look like this :

<VirtualHost *:80>
    ServerName localhost
    DocumentRoot D:/wamp/www
    <Directory  "D:/wamp/www/">
        Options +Indexes +FollowSymLinks +MultiViews
        AllowOverride All
        Require local
    </Directory>
</VirtualHost>

Amend it to

<VirtualHost *:80>
    ServerName localhost
    DocumentRoot D:/wamp/www
    <Directory  "D:/wamp/www/">
        Options +Indexes +FollowSymLinks +MultiViews
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

Hopefully you will have created a Virtual Host for your project and not be using the wamp\www folder for your site. In that case leave the localhost definition alone and make the change only to your Virtual Host.

Dont forget to restart Apache after making this change

How to solve the system.data.sqlclient.sqlexception (0x80131904) error

Well, did you DO what the error says? You go to some length telling about installation, but what about the obvious?

  • Check the other server's network configuration in SQL Server.
  • Check the other machines FIREWALL. SQL Server does not open ports automatically, so the windows firewall normally blocks access..

Git: Merge a Remote branch locally

If you already fetched your remote branch and do git branch -a,
you obtain something like :

* 8.0
  xxx
  remotes/origin/xxx
  remotes/origin/8.0
  remotes/origin/HEAD -> origin/8.0
  remotes/rep_mirror/8.0

After that, you can use rep_mirror/8.0 to designate locally your remote branch.

The trick is that remotes/rep_mirror/8.0 doesn't work but rep_mirror/8.0 does.

So, a command like git merge -m "my msg" rep_mirror/8.0 do the merge.

(note : this is a comment to @VonC answer. I put it as another answer because code blocks don't fit into the comment format)

How to create multiple class objects with a loop in python?

you can use list to define it.

objs = list()
for i in range(10):
    objs.append(MyClass())

The network path was not found

I recently had the same issue. It's more likely that your application can not connect to database server due to the network issues.

In my case I was connected to wrong WiFi.

data.table vs dplyr: can one do something well the other can't or does poorly?

We need to cover at least these aspects to provide a comprehensive answer/comparison (in no particular order of importance): Speed, Memory usage, Syntax and Features.

My intent is to cover each one of these as clearly as possible from data.table perspective.

Note: unless explicitly mentioned otherwise, by referring to dplyr, we refer to dplyr's data.frame interface whose internals are in C++ using Rcpp.


The data.table syntax is consistent in its form - DT[i, j, by]. To keep i, j and by together is by design. By keeping related operations together, it allows to easily optimise operations for speed and more importantly memory usage, and also provide some powerful features, all while maintaining the consistency in syntax.

1. Speed

Quite a few benchmarks (though mostly on grouping operations) have been added to the question already showing data.table gets faster than dplyr as the number of groups and/or rows to group by increase, including benchmarks by Matt on grouping from 10 million to 2 billion rows (100GB in RAM) on 100 - 10 million groups and varying grouping columns, which also compares pandas. See also updated benchmarks, which include Spark and pydatatable as well.

On benchmarks, it would be great to cover these remaining aspects as well:

  • Grouping operations involving a subset of rows - i.e., DT[x > val, sum(y), by = z] type operations.

  • Benchmark other operations such as update and joins.

  • Also benchmark memory footprint for each operation in addition to runtime.

2. Memory usage

  1. Operations involving filter() or slice() in dplyr can be memory inefficient (on both data.frames and data.tables). See this post.

    Note that Hadley's comment talks about speed (that dplyr is plentiful fast for him), whereas the major concern here is memory.

  2. data.table interface at the moment allows one to modify/update columns by reference (note that we don't need to re-assign the result back to a variable).

    # sub-assign by reference, updates 'y' in-place
    DT[x >= 1L, y := NA]
    

    But dplyr will never update by reference. The dplyr equivalent would be (note that the result needs to be re-assigned):

    # copies the entire 'y' column
    ans <- DF %>% mutate(y = replace(y, which(x >= 1L), NA))
    

    A concern for this is referential transparency. Updating a data.table object by reference, especially within a function may not be always desirable. But this is an incredibly useful feature: see this and this posts for interesting cases. And we want to keep it.

    Therefore we are working towards exporting shallow() function in data.table that will provide the user with both possibilities. For example, if it is desirable to not modify the input data.table within a function, one can then do:

    foo <- function(DT) {
        DT = shallow(DT)          ## shallow copy DT
        DT[, newcol := 1L]        ## does not affect the original DT 
        DT[x > 2L, newcol := 2L]  ## no need to copy (internally), as this column exists only in shallow copied DT
        DT[x > 2L, x := 3L]       ## have to copy (like base R / dplyr does always); otherwise original DT will 
                                  ## also get modified.
    }
    

    By not using shallow(), the old functionality is retained:

    bar <- function(DT) {
        DT[, newcol := 1L]        ## old behaviour, original DT gets updated by reference
        DT[x > 2L, x := 3L]       ## old behaviour, update column x in original DT.
    }
    

    By creating a shallow copy using shallow(), we understand that you don't want to modify the original object. We take care of everything internally to ensure that while also ensuring to copy columns you modify only when it is absolutely necessary. When implemented, this should settle the referential transparency issue altogether while providing the user with both possibilties.

    Also, once shallow() is exported dplyr's data.table interface should avoid almost all copies. So those who prefer dplyr's syntax can use it with data.tables.

    But it will still lack many features that data.table provides, including (sub)-assignment by reference.

  3. Aggregate while joining:

    Suppose you have two data.tables as follows:

    DT1 = data.table(x=c(1,1,1,1,2,2,2,2), y=c("a", "a", "b", "b"), z=1:8, key=c("x", "y"))
    #    x y z
    # 1: 1 a 1
    # 2: 1 a 2
    # 3: 1 b 3
    # 4: 1 b 4
    # 5: 2 a 5
    # 6: 2 a 6
    # 7: 2 b 7
    # 8: 2 b 8
    DT2 = data.table(x=1:2, y=c("a", "b"), mul=4:3, key=c("x", "y"))
    #    x y mul
    # 1: 1 a   4
    # 2: 2 b   3
    

    And you would like to get sum(z) * mul for each row in DT2 while joining by columns x,y. We can either:

    • 1) aggregate DT1 to get sum(z), 2) perform a join and 3) multiply (or)

      # data.table way
      DT1[, .(z = sum(z)), keyby = .(x,y)][DT2][, z := z*mul][]
      
      # dplyr equivalent
      DF1 %>% group_by(x, y) %>% summarise(z = sum(z)) %>% 
          right_join(DF2) %>% mutate(z = z * mul)
      
    • 2) do it all in one go (using by = .EACHI feature):

      DT1[DT2, list(z=sum(z) * mul), by = .EACHI]
      

    What is the advantage?

    • We don't have to allocate memory for the intermediate result.

    • We don't have to group/hash twice (one for aggregation and other for joining).

    • And more importantly, the operation what we wanted to perform is clear by looking at j in (2).

    Check this post for a detailed explanation of by = .EACHI. No intermediate results are materialised, and the join+aggregate is performed all in one go.

    Have a look at this, this and this posts for real usage scenarios.

    In dplyr you would have to join and aggregate or aggregate first and then join, neither of which are as efficient, in terms of memory (which in turn translates to speed).

  4. Update and joins:

    Consider the data.table code shown below:

    DT1[DT2, col := i.mul]
    

    adds/updates DT1's column col with mul from DT2 on those rows where DT2's key column matches DT1. I don't think there is an exact equivalent of this operation in dplyr, i.e., without avoiding a *_join operation, which would have to copy the entire DT1 just to add a new column to it, which is unnecessary.

    Check this post for a real usage scenario.

To summarise, it is important to realise that every bit of optimisation matters. As Grace Hopper would say, Mind your nanoseconds!

3. Syntax

Let's now look at syntax. Hadley commented here:

Data tables are extremely fast but I think their concision makes it harder to learn and code that uses it is harder to read after you have written it ...

I find this remark pointless because it is very subjective. What we can perhaps try is to contrast consistency in syntax. We will compare data.table and dplyr syntax side-by-side.

We will work with the dummy data shown below:

DT = data.table(x=1:10, y=11:20, z=rep(1:2, each=5))
DF = as.data.frame(DT)
  1. Basic aggregation/update operations.

    # case (a)
    DT[, sum(y), by = z]                       ## data.table syntax
    DF %>% group_by(z) %>% summarise(sum(y)) ## dplyr syntax
    DT[, y := cumsum(y), by = z]
    ans <- DF %>% group_by(z) %>% mutate(y = cumsum(y))
    
    # case (b)
    DT[x > 2, sum(y), by = z]
    DF %>% filter(x>2) %>% group_by(z) %>% summarise(sum(y))
    DT[x > 2, y := cumsum(y), by = z]
    ans <- DF %>% group_by(z) %>% mutate(y = replace(y, which(x > 2), cumsum(y)))
    
    # case (c)
    DT[, if(any(x > 5L)) y[1L]-y[2L] else y[2L], by = z]
    DF %>% group_by(z) %>% summarise(if (any(x > 5L)) y[1L] - y[2L] else y[2L])
    DT[, if(any(x > 5L)) y[1L] - y[2L], by = z]
    DF %>% group_by(z) %>% filter(any(x > 5L)) %>% summarise(y[1L] - y[2L])
    
    • data.table syntax is compact and dplyr's quite verbose. Things are more or less equivalent in case (a).

    • In case (b), we had to use filter() in dplyr while summarising. But while updating, we had to move the logic inside mutate(). In data.table however, we express both operations with the same logic - operate on rows where x > 2, but in first case, get sum(y), whereas in the second case update those rows for y with its cumulative sum.

      This is what we mean when we say the DT[i, j, by] form is consistent.

    • Similarly in case (c), when we have if-else condition, we are able to express the logic "as-is" in both data.table and dplyr. However, if we would like to return just those rows where the if condition satisfies and skip otherwise, we cannot use summarise() directly (AFAICT). We have to filter() first and then summarise because summarise() always expects a single value.

      While it returns the same result, using filter() here makes the actual operation less obvious.

      It might very well be possible to use filter() in the first case as well (does not seem obvious to me), but my point is that we should not have to.

  2. Aggregation / update on multiple columns

    # case (a)
    DT[, lapply(.SD, sum), by = z]                     ## data.table syntax
    DF %>% group_by(z) %>% summarise_each(funs(sum)) ## dplyr syntax
    DT[, (cols) := lapply(.SD, sum), by = z]
    ans <- DF %>% group_by(z) %>% mutate_each(funs(sum))
    
    # case (b)
    DT[, c(lapply(.SD, sum), lapply(.SD, mean)), by = z]
    DF %>% group_by(z) %>% summarise_each(funs(sum, mean))
    
    # case (c)
    DT[, c(.N, lapply(.SD, sum)), by = z]     
    DF %>% group_by(z) %>% summarise_each(funs(n(), mean))
    
    • In case (a), the codes are more or less equivalent. data.table uses familiar base function lapply(), whereas dplyr introduces *_each() along with a bunch of functions to funs().

    • data.table's := requires column names to be provided, whereas dplyr generates it automatically.

    • In case (b), dplyr's syntax is relatively straightforward. Improving aggregations/updates on multiple functions is on data.table's list.

    • In case (c) though, dplyr would return n() as many times as many columns, instead of just once. In data.table, all we need to do is to return a list in j. Each element of the list will become a column in the result. So, we can use, once again, the familiar base function c() to concatenate .N to a list which returns a list.

    Note: Once again, in data.table, all we need to do is return a list in j. Each element of the list will become a column in result. You can use c(), as.list(), lapply(), list() etc... base functions to accomplish this, without having to learn any new functions.

    You will need to learn just the special variables - .N and .SD at least. The equivalent in dplyr are n() and .

  3. Joins

    dplyr provides separate functions for each type of join where as data.table allows joins using the same syntax DT[i, j, by] (and with reason). It also provides an equivalent merge.data.table() function as an alternative.

    setkey(DT1, x, y)
    
    # 1. normal join
    DT1[DT2]            ## data.table syntax
    left_join(DT2, DT1) ## dplyr syntax
    
    # 2. select columns while join    
    DT1[DT2, .(z, i.mul)]
    left_join(select(DT2, x, y, mul), select(DT1, x, y, z))
    
    # 3. aggregate while join
    DT1[DT2, .(sum(z) * i.mul), by = .EACHI]
    DF1 %>% group_by(x, y) %>% summarise(z = sum(z)) %>% 
        inner_join(DF2) %>% mutate(z = z*mul) %>% select(-mul)
    
    # 4. update while join
    DT1[DT2, z := cumsum(z) * i.mul, by = .EACHI]
    ??
    
    # 5. rolling join
    DT1[DT2, roll = -Inf]
    ??
    
    # 6. other arguments to control output
    DT1[DT2, mult = "first"]
    ??
    
    • Some might find a separate function for each joins much nicer (left, right, inner, anti, semi etc), whereas as others might like data.table's DT[i, j, by], or merge() which is similar to base R.

    • However dplyr joins do just that. Nothing more. Nothing less.

    • data.tables can select columns while joining (2), and in dplyr you will need to select() first on both data.frames before to join as shown above. Otherwise you would materialiase the join with unnecessary columns only to remove them later and that is inefficient.

    • data.tables can aggregate while joining (3) and also update while joining (4), using by = .EACHI feature. Why materialse the entire join result to add/update just a few columns?

    • data.table is capable of rolling joins (5) - roll forward, LOCF, roll backward, NOCB, nearest.

    • data.table also has mult = argument which selects first, last or all matches (6).

    • data.table has allow.cartesian = TRUE argument to protect from accidental invalid joins.

Once again, the syntax is consistent with DT[i, j, by] with additional arguments allowing for controlling the output further.

  1. do()...

    dplyr's summarise is specially designed for functions that return a single value. If your function returns multiple/unequal values, you will have to resort to do(). You have to know beforehand about all your functions return value.

    DT[, list(x[1], y[1]), by = z]                 ## data.table syntax
    DF %>% group_by(z) %>% summarise(x[1], y[1]) ## dplyr syntax
    DT[, list(x[1:2], y[1]), by = z]
    DF %>% group_by(z) %>% do(data.frame(.$x[1:2], .$y[1]))
    
    DT[, quantile(x, 0.25), by = z]
    DF %>% group_by(z) %>% summarise(quantile(x, 0.25))
    DT[, quantile(x, c(0.25, 0.75)), by = z]
    DF %>% group_by(z) %>% do(data.frame(quantile(.$x, c(0.25, 0.75))))
    
    DT[, as.list(summary(x)), by = z]
    DF %>% group_by(z) %>% do(data.frame(as.list(summary(.$x))))
    
    • .SD's equivalent is .

    • In data.table, you can throw pretty much anything in j - the only thing to remember is for it to return a list so that each element of the list gets converted to a column.

    • In dplyr, cannot do that. Have to resort to do() depending on how sure you are as to whether your function would always return a single value. And it is quite slow.

Once again, data.table's syntax is consistent with DT[i, j, by]. We can just keep throwing expressions in j without having to worry about these things.

Have a look at this SO question and this one. I wonder if it would be possible to express the answer as straightforward using dplyr's syntax...

To summarise, I have particularly highlighted several instances where dplyr's syntax is either inefficient, limited or fails to make operations straightforward. This is particularly because data.table gets quite a bit of backlash about "harder to read/learn" syntax (like the one pasted/linked above). Most posts that cover dplyr talk about most straightforward operations. And that is great. But it is important to realise its syntax and feature limitations as well, and I am yet to see a post on it.

data.table has its quirks as well (some of which I have pointed out that we are attempting to fix). We are also attempting to improve data.table's joins as I have highlighted here.

But one should also consider the number of features that dplyr lacks in comparison to data.table.

4. Features

I have pointed out most of the features here and also in this post. In addition:

  • fread - fast file reader has been available for a long time now.

  • fwrite - a parallelised fast file writer is now available. See this post for a detailed explanation on the implementation and #1664 for keeping track of further developments.

  • Automatic indexing - another handy feature to optimise base R syntax as is, internally.

  • Ad-hoc grouping: dplyr automatically sorts the results by grouping variables during summarise(), which may not be always desirable.

  • Numerous advantages in data.table joins (for speed / memory efficiency and syntax) mentioned above.

  • Non-equi joins: Allows joins using other operators <=, <, >, >= along with all other advantages of data.table joins.

  • Overlapping range joins was implemented in data.table recently. Check this post for an overview with benchmarks.

  • setorder() function in data.table that allows really fast reordering of data.tables by reference.

  • dplyr provides interface to databases using the same syntax, which data.table does not at the moment.

  • data.table provides faster equivalents of set operations (written by Jan Gorecki) - fsetdiff, fintersect, funion and fsetequal with additional all argument (as in SQL).

  • data.table loads cleanly with no masking warnings and has a mechanism described here for [.data.frame compatibility when passed to any R package. dplyr changes base functions filter, lag and [ which can cause problems; e.g. here and here.


Finally:

  • On databases - there is no reason why data.table cannot provide similar interface, but this is not a priority now. It might get bumped up if users would very much like that feature.. not sure.

  • On parallelism - Everything is difficult, until someone goes ahead and does it. Of course it will take effort (being thread safe).

    • Progress is being made currently (in v1.9.7 devel) towards parallelising known time consuming parts for incremental performance gains using OpenMP.

"The system cannot find the file specified"

Server Error in '/' Application.

The system cannot find the file specified

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ComponentModel.Win32Exception: The system cannot find the file specified

Source Error:

     {
                   SqlCommand cmd = new SqlCommand("select * from tblemployee",con);
                   con.Open();
                   GridView1.DataSource = cmd.ExecuteReader();
                   GridView1.DataBind();

Source File: d:\C# programs\kudvenkat\adobasics1\adobasics1\employeedata.aspx.cs Line: 23

if your error is same like mine..just do this

right click on your table in sqlserver object explorer,choose properties in lower left corner in general option there is a connection block with server and connection specification.in your web config for datasource=. or local choose name specified in server in properties..

The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security

I recently started receiving this error inside of my internal NLog failures log, with Visual Studio 2013. The solution has been using NLog v2.0.0 for several years. Within the last month, our main log stopped working. To fix this I updated NLog to the newest version (v3.1.0) via Nuget. The security exception is now gone and ALL of the log messages are appearing again.

Additionally, I later found another Security exception and was able to fix it by following the instructions on this post in another thread.

browser sessionStorage. share between tabs?

  1. You can just use localStorage and remember the date it was first created in session cookie. When localStorage "session" is older than the value of cookie then you may clear the localStorage

    Cons of this is that someone can still read the data after the browser is closed so it's not a good solution if your data is private and confidental.

  2. You can store your data to localStorage for a couple of seconds and add event listener for a storage event. This way you will know when any of the tabs wrote something to the localStorage and you can copy its content to the sessionStorage, then just clear the localStorage

Exit single-user mode

  1. Right click your database in databases section
  2. Select "Properties"
  3. Select "Options" page
  4. Scroll down "Other options" and alter "Restrict access" field

screenshot of options page of sql server

Run command on the Ansible host

I've found a couple other ways you can write these which are a bit more readable IMHO.

- name: check out a git repository
  local_action: 
    module: git
    repo: git://foosball.example.org/path/to/repo.git
    dest: /local/path

OR

- name: check out a git repository
  local_action: git
  args:
    repo: git://foosball.example.org/path/to/repo.git
    dest: /local/path

Connecting to SQL Server using windows authentication

A connection string for SQL Server should look more like: "Server= localhost; Database= employeedetails; Integrated Security=True;"

If you have a named instance of SQL Server, you'll need to add that as well, e.g., "Server=localhost\sqlexpress"

How to access model hasMany Relation with where condition?

Just in case anyone else encounters the same problems.

Note, that relations are required to be camelcase. So in my case available_videos() should have been availableVideos().

You can easily find out investigating the Laravel source:

// Illuminate\Database\Eloquent\Model.php
...
/**
 * Get an attribute from the model.
 *
 * @param  string  $key
 * @return mixed
 */
public function getAttribute($key)
{
    $inAttributes = array_key_exists($key, $this->attributes);

    // If the key references an attribute, we can just go ahead and return the
    // plain attribute value from the model. This allows every attribute to
    // be dynamically accessed through the _get method without accessors.
    if ($inAttributes || $this->hasGetMutator($key))
    {
        return $this->getAttributeValue($key);
    }

    // If the key already exists in the relationships array, it just means the
    // relationship has already been loaded, so we'll just return it out of
    // here because there is no need to query within the relations twice.
    if (array_key_exists($key, $this->relations))
    {
        return $this->relations[$key];
    }

    // If the "attribute" exists as a method on the model, we will just assume
    // it is a relationship and will load and return results from the query
    // and hydrate the relationship's value on the "relationships" array.
    $camelKey = camel_case($key);

    if (method_exists($this, $camelKey))
    {
        return $this->getRelationshipFromMethod($key, $camelKey);
    }
}

This also explains why my code worked, whenever I loaded the data using the load() method before.

Anyway, my example works perfectly okay now, and $model->availableVideos always returns a Collection.

"Unable to launch the IIS Express Web server" error

The one thing that fixed this for me was using the following line in the <bindings> section for my site in the applicationhost.config file:

<bindings>
    <binding protocol="http" bindingInformation="*:8099:" />
</bindings>

The key was to simply remove localhost. Don't replace it with an asterisk, don't replace it with an IP or a computer name. Just leave it blank after the colon.

After doing this, I don't need to run Visual Studio as administrator, and I can freely change the Project Url in the project properties to the local IP or computer name. I then set up port forwarding and it was accessible to the Internet.

EDIT:

I've discovered one more quirk that is important to getting IIS Express to properly serve external requests.

  1. If you are running Visual Studio/IIS Express as an administrator, you must not add a reservation to HTTP.SYS using the "netsh http add urlacl ..." command. Doing so will cause an HTTP 503 Service Unavailable error. Delete any reservations you've made in the URLACL to fix this.

  2. If you are not running Visual Studio/IIS Express as an administrator, you must add a reservation to the URLACL.

Public class is inaccessible due to its protection level

This error is a result of the protection level of ClassB's constructor, not ClassB itself. Since the name of the constructor is the same as the name of the class* , the error may be interpreted incorrectly. Since you did not specify the protection level of your constructor, it is assumed to be internal by default. Declaring the constructor public will fix this problem:

public ClassB() { } 

* One could also say that constructors have no name, only a type; this does not change the essence of the problem.

Delete a closed pull request from GitHub

5 step to do what you want if you made the pull request from a forked repository:

  1. reopen the pull request
  2. checkout to the branch which you made the pull request
  3. reset commit to the last master commit(that means remove all you new code)
  4. git push --force
  5. delete your forked repository which made the pull request

And everything is done, good luck!

Entity Framework The underlying provider failed on Open

open SQL Server Configuration Manager then click on sql server services a list will be displayed from the list right click sql server and click on start

Why am I getting "Cannot Connect to Server - A network-related or instance-specific error"?

Press window + R (Run window Open) and in run window type "services.msc" and new services open find SQL SERVER with instance name in my case it's SQL SERVER(SQLEXPRESS) then start this service and try again it works for me Hope Its Works for You also.enter image description here

JavaScript module pattern with example

In order to approach to Modular design pattern, you need to understand these concept first:

Immediately-Invoked Function Expression (IIFE):

(function() {
      // Your code goes here 
}());

There are two ways you can use the functions. 1. Function declaration 2. Function expression.

Here are using function expression.

What is namespace? Now if we add the namespace to the above piece of code then

var anoyn = (function() {
}());

What is closure in JS?

It means if we declare any function with any variable scope/inside another function (in JS we can declare a function inside another function!) then it will count that function scope always. This means that any variable in outer function will be read always. It will not read the global variable (if any) with the same name. This is also one of the objective of using modular design pattern avoiding naming conflict.

var scope = "I am global";
function whatismyscope() {
    var scope = "I am just a local";
    function func() {return scope;}
    return func;
}
whatismyscope()()

Now we will apply these three concepts I mentioned above to define our first modular design pattern:

var modularpattern = (function() {
    // your module code goes here
    var sum = 0 ;

    return {
        add:function() {
            sum = sum + 1;
            return sum;
        },
        reset:function() {
            return sum = 0;    
        }  
    }   
}());
alert(modularpattern.add());    // alerts: 1
alert(modularpattern.add());    // alerts: 2
alert(modularpattern.reset());  // alerts: 0

jsfiddle for the code above.

The objective is to hide the variable accessibility from the outside world.

Hope this helps. Good Luck.

How is attr_accessible used in Rails 4?

Rails 4 now uses strong parameters.

Protecting attributes is now done in the controller. This is an example:

class PeopleController < ApplicationController
  def create
    Person.create(person_params)
  end

  private

  def person_params
    params.require(:person).permit(:name, :age)
  end
end

No need to set attr_accessible in the model anymore.

Dealing with accepts_nested_attributes_for

In order to use accepts_nested_attribute_for with strong parameters, you will need to specify which nested attributes should be whitelisted.

class Person
  has_many :pets
  accepts_nested_attributes_for :pets
end

class PeopleController < ApplicationController
  def create
    Person.create(person_params)
  end

  # ...

  private

  def person_params
    params.require(:person).permit(:name, :age, pets_attributes: [:name, :category])
  end
end

Keywords are self-explanatory, but just in case, you can find more information about strong parameters in the Rails Action Controller guide.

Note: If you still want to use attr_accessible, you need to add protected_attributes to your Gemfile. Otherwise, you will be faced with a RuntimeError.

How to create global variables accessible in all views using Express / Node.JS?

After having a chance to study the Express 3 API Reference a bit more I discovered what I was looking for. Specifically the entries for app.locals and then a bit farther down res.locals held the answers I needed.

I discovered for myself that the function app.locals takes an object and stores all of its properties as global variables scoped to the application. These globals are passed as local variables to each view. The function res.locals, however, is scoped to the request and thus, response local variables are accessible only to the view(s) rendered during that particular request/response.

So for my case in my app.js what I did was add:

app.locals({
    site: {
        title: 'ExpressBootstrapEJS',
        description: 'A boilerplate for a simple web application with a Node.JS and Express backend, with an EJS template with using Twitter Bootstrap.'
    },
    author: {
        name: 'Cory Gross',
        contact: '[email protected]'
    }
});

Then all of these variables are accessible in my views as site.title, site.description, author.name, author.contact.

I could also define local variables for each response to a request with res.locals, or simply pass variables like the page's title in as the optionsparameter in the render call.

EDIT: This method will not allow you to use these locals in your middleware. I actually did run into this as Pickels suggests in the comment below. In this case you will need to create a middleware function as such in his alternative (and appreciated) answer. Your middleware function will need to add them to res.locals for each response and then call next. This middleware function will need to be placed above any other middleware which needs to use these locals.

EDIT: Another difference between declaring locals via app.locals and res.locals is that with app.locals the variables are set a single time and persist throughout the life of the application. When you set locals with res.locals in your middleware, these are set everytime you get a request. You should basically prefer setting globals via app.locals unless the value depends on the request req variable passed into the middleware. If the value doesn't change then it will be more efficient for it to be set just once in app.locals.

A network-related or instance-specific error occurred while establishing a connection to SQL Server

Sql Server fire this error when your application don't have enough rights to access the database. there are several reason about this error . To fix this error you should follow the following instruction.

  1. Try to connect sql server from your server using management studio . if you use windows authentication to connect sql server then set your application pool identity to server administrator .

  2. if you use sql server authentication then check you connection string in web.config of your web application and set user id and password of sql server which allows you to log in .

  3. if your database in other server(access remote database) then first of enable remote access of sql server form sql server property from sql server management studio and enable TCP/IP form sql server configuration manager .

  4. after doing all these stuff and you still can't access the database then check firewall of server form where you are trying to access the database and add one rule in firewall to enable port of sql server(by default sql server use 1433 , to check port of sql server you need to check sql server configuration manager network protocol TCP/IP port).

  5. if your sql server is running on named instance then you need to write port number with sql serer name for example 117.312.21.21/nameofsqlserver,1433.

  6. If you are using cloud hosting like amazon aws or microsoft azure then server or instance will running behind cloud firewall so you need to enable 1433 port in cloud firewall if you have default instance or specific port for sql server for named instance.

  7. If you are using amazon RDS or SQL azure then you need to enable port from security group of that instance.

  8. If you are accessing sql server through sql server authentication mode them make sure you enabled "SQL Server and Windows Authentication Mode" sql server instance property. enter image description here

    1. Restart your sql server instance after making any changes in property as some changes will require restart.

if you further face any difficulty then you need to provide more information about your web site and sql server .

Use SQL Server Management Studio to connect remotely to an SQL Server Express instance hosted on an Azure Virtual Machine

Here are the three web pages on which we found the answer. The most difficult part was setting up static ports for SQLEXPRESS.

Provisioning a SQL Server Virtual Machine on Windows Azure. These initial instructions provided 25% of the answer.

How to Troubleshoot Connecting to the SQL Server Database Engine. Reading this carefully provided another 50% of the answer.

How to configure SQL server to listen on different ports on different IP addresses?. This enabled setting up static ports for named instances (eg SQLEXPRESS.) It took us the final 25% of the way to the answer.

An attempt was made to access a socket in a way forbidden by its access permissions

My windows firewall was blocking port 8080 so i changed it to 5000 and it worked!

Notice: Undefined variable: _SESSION in "" on line 9

First, you'll need to add session_start() at the top of any page that you wish to use SESSION variables on.

Also, you should check to make sure the variable is set first before using it:

if(isset($_SESSION['SESS_fname'])){
    echo $_SESSION['SESS_fname'];
}

Or, simply:

echo (isset($_SESSION['SESS_fname']) ? $_SESSION['SESS_fname'] : "Visitor");

How do AX, AH, AL map onto EAX?

AX is the 16 lower bits of EAX. AH is the 8 high bits of AX (i.e. the bits 8-15 of EAX) and AL is the least significant byte (bits 0-7) of EAX as well as AX.

Example (Hexadecimal digits):

EAX: 12 34 56 78
AX: 56 78
AH: 56
AL: 78

PHP CURL CURLOPT_SSL_VERIFYPEER ignored

We had the same problem on a CentOS7 machine. Disabling the VERIFYHOST VERIFYPEER did not solve the problem, we did not have the cURL error anymore but the response still was invalid. Doing a wget to the same link as the cURL was doing also resulted in a certificate error.

-> Our solution also was to reboot the VPS, this solved it and we were able to complete the request again.

For us this seemed to be a memory corruption problem. Rebooting the VPS reloaded the libary in the memory again and now it works. So if the above solution from @clover does not work try to reboot your machine.

Can I make a function available in every controller in angular?

Though the first approach is advocated as 'the angular like' approach, I feel this adds overheads.

Consider if I want to use this myservice.foo function in 10 different controllers. I will have to specify this 'myService' dependency and then $scope.callFoo scope property in all ten of them. This is simply a repetition and somehow violates the DRY principle.

Whereas, if I use the $rootScope approach, I specify this global function gobalFoo only once and it will be available in all my future controllers, no matter how many.

Dynamically load JS inside JS

Necromancing.

I use this to load dependant scripts;
it works with IE8+ without adding any dependency on another library like jQuery !

var cScriptLoader = (function ()
{
    function cScriptLoader(files)
    {
        var _this = this;
        this.log = function (t)
        {
            console.log("ScriptLoader: " + t);
        };
        this.withNoCache = function (filename)
        {
            if (filename.indexOf("?") === -1)
                filename += "?no_cache=" + new Date().getTime();
            else
                filename += "&no_cache=" + new Date().getTime();
            return filename;
        };
        this.loadStyle = function (filename)
        {
            // HTMLLinkElement
            var link = document.createElement("link");
            link.rel = "stylesheet";
            link.type = "text/css";
            link.href = _this.withNoCache(filename);
            _this.log('Loading style ' + filename);
            link.onload = function ()
            {
                _this.log('Loaded style "' + filename + '".');
            };
            link.onerror = function ()
            {
                _this.log('Error loading style "' + filename + '".');
            };
            _this.m_head.appendChild(link);
        };
        this.loadScript = function (i)
        {
            var script = document.createElement('script');
            script.type = 'text/javascript';
            script.src = _this.withNoCache(_this.m_js_files[i]);
            var loadNextScript = function ()
            {
                if (i + 1 < _this.m_js_files.length)
                {
                    _this.loadScript(i + 1);
                }
            };
            script.onload = function ()
            {
                _this.log('Loaded script "' + _this.m_js_files[i] + '".');
                loadNextScript();
            };
            script.onerror = function ()
            {
                _this.log('Error loading script "' + _this.m_js_files[i] + '".');
                loadNextScript();
            };
            _this.log('Loading script "' + _this.m_js_files[i] + '".');
            _this.m_head.appendChild(script);
        };
        this.loadFiles = function ()
        {
            // this.log(this.m_css_files);
            // this.log(this.m_js_files);
            for (var i = 0; i < _this.m_css_files.length; ++i)
                _this.loadStyle(_this.m_css_files[i]);
            _this.loadScript(0);
        };
        this.m_js_files = [];
        this.m_css_files = [];
        this.m_head = document.getElementsByTagName("head")[0];
        // this.m_head = document.head; // IE9+ only
        function endsWith(str, suffix)
        {
            if (str === null || suffix === null)
                return false;
            return str.indexOf(suffix, str.length - suffix.length) !== -1;
        }
        for (var i = 0; i < files.length; ++i)
        {
            if (endsWith(files[i], ".css"))
            {
                this.m_css_files.push(files[i]);
            }
            else if (endsWith(files[i], ".js"))
            {
                this.m_js_files.push(files[i]);
            }
            else
                this.log('Error unknown filetype "' + files[i] + '".');
        }
    }
    return cScriptLoader;
})();
var ScriptLoader = new cScriptLoader(["foo.css", "Scripts/Script4.js", "foobar.css", "Scripts/Script1.js", "Scripts/Script2.js", "Scripts/Script3.js"]);
ScriptLoader.loadFiles();

If you are interested in the typescript-version used to create this:

class cScriptLoader {
    private m_js_files: string[];
    private m_css_files: string[];
    private m_head:HTMLHeadElement;
    
    private log = (t:any) =>
    {
        console.log("ScriptLoader: " + t);
    }
    
    
    constructor(files: string[]) {
        this.m_js_files = [];
        this.m_css_files = [];
        this.m_head = document.getElementsByTagName("head")[0];
        // this.m_head = document.head; // IE9+ only
        
        
        function endsWith(str:string, suffix:string):boolean 
        {
            if(str === null || suffix === null)
                return false;
                
            return str.indexOf(suffix, str.length - suffix.length) !== -1;
        }
        
        
        for(let i:number = 0; i < files.length; ++i) 
        {
            if(endsWith(files[i], ".css"))
            {
                this.m_css_files.push(files[i]);
            }
            else if(endsWith(files[i], ".js"))
            {
                this.m_js_files.push(files[i]);
            }
            else
                this.log('Error unknown filetype "' + files[i] +'".');
        }
        
    }
    
    
    public withNoCache = (filename:string):string =>
    {
        if(filename.indexOf("?") === -1)
            filename += "?no_cache=" + new Date().getTime();
        else
            filename += "&no_cache=" + new Date().getTime();
            
        return filename;    
    }
    

    public loadStyle = (filename:string) =>
    {
        // HTMLLinkElement
        let link = document.createElement("link");
        link.rel = "stylesheet";
        link.type = "text/css";
        link.href = this.withNoCache(filename);
        
        this.log('Loading style ' + filename);
        link.onload = () =>
        {
            this.log('Loaded style "' + filename + '".');
            
        };
        
        link.onerror = () =>
        {
            this.log('Error loading style "' + filename + '".');
        };
        
        this.m_head.appendChild(link);
    }
    
    
    public loadScript = (i:number) => 
    {
        let script = document.createElement('script');
        script.type = 'text/javascript';
        script.src = this.withNoCache(this.m_js_files[i]);
        
        var loadNextScript = () => 
        {
            if (i + 1 < this.m_js_files.length)
            {
                this.loadScript(i + 1);
            }
        }
        
        script.onload = () =>
        {
            this.log('Loaded script "' + this.m_js_files[i] + '".');
            loadNextScript();
        };
        
        
        script.onerror = () =>
        {
            this.log('Error loading script "' + this.m_js_files[i] + '".');
            loadNextScript();
        };
        
        
        this.log('Loading script "' + this.m_js_files[i] + '".');
        this.m_head.appendChild(script);
    }
    
    public loadFiles = () => 
    {
        // this.log(this.m_css_files);
        // this.log(this.m_js_files);
        
        for(let i:number = 0; i < this.m_css_files.length; ++i)
            this.loadStyle(this.m_css_files[i])
        
        this.loadScript(0);
    }
    
}


var ScriptLoader = new cScriptLoader(["foo.css", "Scripts/Script4.js", "foobar.css", "Scripts/Script1.js", "Scripts/Script2.js", "Scripts/Script3.js"]);
ScriptLoader.loadFiles();

If it's to load a dynamic list of scripts, write the scripts into an attribute, such as data-main, e.g. <script src="scriptloader.js" data-main="file1.js,file2.js,file3.js,etc." ></script>
and do a element.getAttribute("data-main").split(',')

such as

var target = document.currentScript || (function() {
  var scripts = document.getElementsByTagName('script');
  // Note: this is for IE as IE doesn't support currentScript
  // this does not work if you have deferred loading with async
  // e.g. <script src="..." async="async" ></script>
  // https://web.archive.org/web/20180618155601/https://www.w3schools.com/TAgs/att_script_async.asp
  return scripts[scripts.length - 1];
})();

target.getAttribute("data-main").split(',')

to obtain the list.

IIS - can't access page by ip address instead of localhost

So I had this same problem with WSUS and it turned out that IIS 8.5 was not binding to my ipv4 ip address, but was binding to ipv6 address. when I accessed it via localhost:8580 it would translate it to the ipv6 localhost address, and thus would work. Accessing it via ip was a no go. I had to manually bind the address using netsh, then it worked right away. bloody annoying.

Steps:

  1. Open command prompt as administrator
  2. Type the following:

netsh http add iplisten ipaddress (IPADDRESSOFYOURSERVER)

that's it. You should get:

IP address successfully added

I found the commands here https://serverfault.com/questions/123796/get-iis-7-5-to-listen-on-ipv6

What is the significance of url-pattern in web.xml and how to configure servlet?

Servlet-mapping has two child tags, url-pattern and servlet-name. url-pattern specifies the type of urls for which, the servlet given in servlet-name should be called. Be aware that, the container will use case-sensitive for string comparisons for servlet matching.

First specification of url-pattern a web.xml file for the server context on the servlet container at server .com matches the pattern in <url-pattern>/status/*</url-pattern> as follows:

http://server.com/server/status/synopsis               = Matches
http://server.com/server/status/complete?date=today    = Matches
http://server.com/server/status                        = Matches
http://server.com/server/server1/status                = Does not match

Second specification of url-pattern A context located at the path /examples on the Agent at example.com matches the pattern in <url-pattern>*.map</url-pattern> as follows:

 http://server.com/server/US/Oregon/Portland.map    = Matches
 http://server.com/server/US/server/Seattle.map     = Matches
 http://server.com/server/Paris.France.map          = Matches
 http://server.com/server/US/Oregon/Portland.MAP    = Does not match, the extension is uppercase
 http://example.com/examples/interface/description/mail.mapi  =Does not match, the extension is mapi rather than map`

Third specification of url-mapping,A mapping that contains the pattern <url-pattern>/</url-pattern> matches a request if no other pattern matches. This is the default mapping. The servlet mapped to this pattern is called the default servlet.

The default mapping is often directed to the first page of an application. Explicitly providing a default mapping also ensures that malformed URL requests into the application return are handled by the application rather than returning an error.

The servlet-mapping element below maps the server servlet instance to the default mapping.

<servlet-mapping>
  <servlet-name>server</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

For the context that contains this element, any request that is not handled by another mapping is forwarded to the server servlet.

And Most importantly we should Know about Rule for URL path mapping

  1. The container will try to find an exact match of the path of the request to the path of the servlet. A successful match selects the servlet.
  2. The container will recursively try to match the longest path-prefix. This is done by stepping down the path tree a directory at a time, using the ’/’ character as a path separator. The longest match determines the servlet selected.
  3. If the last segment in the URL path contains an extension (e.g. .jsp), the servlet container will try to match a servlet that handles requests for the extension. An extension is defined as the part of the last segment after the last ’.’ character.
  4. If neither of the previous three rules result in a servlet match, the container will attempt to serve content appropriate for the resource requested. If a “default” servlet is defined for the application, it will be used.

Reference URL Pattern

Create local maven repository

Yes you can! For a simple repository that only publish/retrieve artifacts, you can use nginx.

  1. Make sure nginx has http dav module enabled, it should, but nonetheless verify it.

  2. Configure nginx http dav module:

    In Windows: d:\servers\nginx\nginx.conf

    location / {
        # maven repository
        dav_methods  PUT DELETE MKCOL COPY MOVE;
        create_full_put_path  on;
        dav_access  user:rw group:rw all:r;
    }
    

    In Linux (Ubuntu): /etc/nginx/sites-available/default

    location / {
            # First attempt to serve request as file, then
            # as directory, then fall back to displaying a 404.
            # try_files $uri $uri/ =404;  # IMPORTANT comment this
            dav_methods  PUT DELETE MKCOL COPY MOVE;
            create_full_put_path  on;
            dav_access  user:rw group:rw all:r;
    }
    

    Don't forget to give permissions to the directory where the repo will be located:

    sudo chmod +777 /var/www/html/repository

  3. In your project's pom.xml add the respective configuration:

    Retrieve artifacts:

    <repositories>
        <repository>
            <id>repository</id>
            <url>http://<your.ip.or.hostname>/repository</url>
        </repository>
    </repositories>
    

    Publish artifacts:

    <build>
        <extensions>
            <extension>
                <groupId>org.apache.maven.wagon</groupId>
                <artifactId>wagon-http</artifactId>
                <version>3.2.0</version>
            </extension>
        </extensions>
    </build>
    <distributionManagement>
        <repository>
            <id>repository</id>
            <url>http://<your.ip.or.hostname>/repository</url>
        </repository>
    </distributionManagement>
    
  4. To publish artifacts use mvn deploy. To retrieve artifacts, maven will do it automatically.

And there you have it a simple maven repo.

SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified

Same issue. In my case I solved setting the project as the "StartUp Project".

Inconsistent accessibility: property type is less accessible

make your class public access modifier,

just add public keyword infront of your class name

 namespace Test
{
  public  class Delivery
    {
        private string name;
        private string address;
        private DateTime arrivalTime;

        public string Name
        {
            get { return name; }
            set { name = value; }
        }

        public string Address
        {
            get { return address; }
            set { address = value; }
        }

        public DateTime ArrivlaTime
        {
            get { return arrivalTime; }
            set { arrivalTime = value; }
        }

        public string ToString()
        {
            { return name + address + arrivalTime.ToString(); }
        }
    }
}

How to declare a global variable in php?

$GLOBALS[] is the right solution, but since we're talking about alternatives, a function can also do this job easily:

function capital() {
    return my_var() . ' is the capital of Italy';
}

function my_var() {
    return 'Rome';
}

HTML/Javascript: how to access JSON data loaded in a script tag with src set

You can't load JSON like that, sorry.

I know you're thinking "why I can't I just use src here? I've seen stuff like this...":

<script id="myJson" type="application/json">
 { 
   name: 'Foo' 
 }
</script>

<script type="text/javascript">
    $(function() {
        var x = JSON.parse($('#myJson').html());
        alert(x.name); //Foo
     });
</script>

... well to put it simply, that was just the script tag being "abused" as a data holder. You can do that with all sorts of data. For example, a lot of templating engines leverage script tags to hold templates.

You have a short list of options to load your JSON from a remote file:

  1. Use $.get('your.json') or some other such AJAX method.
  2. Write a file that sets a global variable to your json. (seems hokey).
  3. Pull it into an invisible iframe, then scrape the contents of that after it's loaded (I call this "1997 mode")
  4. Consult a voodoo priest.

Final point:

Remote JSON Request after page loads is also not an option, in case you want to suggest that.

... that doesn't make sense. The difference between an AJAX request and a request sent by the browser while processing your <script src=""> is essentially nothing. They'll both be doing a GET on the resource. HTTP doesn't care if it's done because of a script tag or an AJAX call, and neither will your server.

Reflection generic get field value

You are calling get with the wrong argument.

It should be:

Object value = field.get(object);

SVN Repository on Google Drive or DropBox

While possible, it's potentially very risky - if you attempt to commit changes to the repository from 2 different locations simultaneously, you'll get a giant mess due to the file conflicts. Get a free private SVN host somewhere, or set up a repository on a server you have access to.

Edit based on a recent experience: If you have files open that are managed by Dropbox and your computer crashes, your files may be truncated to 0 bytes. If this happens to the files which manage your repository, your repository will be corrupted. If you discover this soon enough, you can use Dropbox's "recover old version" feature but you're still taking a risk.

Rewrite all requests to index.php with nginx

Here is what worked for me to solve part 1 of this question:

    location / {
            rewrite ^([^.]*[^/])$ $1/ permanent;
            try_files $uri $uri/ /index.php =404;
            include fastcgi_params;
            fastcgi_pass php5-fpm-sock;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_intercept_errors on;
    }

rewrite ^([^.]*[^/])$ $1/ permanent; rewrites non-file addresses (addresses without file extensions) to have a "/" at the end. I did this because I was running into "Access denied." message when I tried to access the folder without it.

try_files $uri $uri/ /index.php =404; is borrowed from SanjuD's answer, but with an extra 404 reroute if the location still isn't found.

fastcgi_index index.php; was the final piece of the puzzle that I was missing. The folder didn't reroute to the index.php without this line.

Remote Procedure call failed with sql server 2008 R2

This error occurs only after I have installed the Microsoft Visual Studio 2012 setup in my work machine.

Since it is being a WMI error, I recompiled the MOF file –> mofcomp.exe "C:\Program Files (x86)\Microsoft SQL Server\100\Shared\sqlmgmproviderxpsp2up.mof"

I also un-registered and re-registered the sql provider DLL –> regsvr32 "C:\Program Files (x86)\Microsoft SQL Server\100\Shared\sqlmgmprovider.dll" but issue not resolved.

Solution:

I have applied SQL Server 2008 R2 SP2 on my SQL 2008 R2 instance and that fixed the issue with Sql Server Configuration Manager. You can download setup from here... http://www.microsoft.com/en-us/download/details.aspx?id=30437 .

How to connect to LocalDb

Your Connection string should be like`

Data Source=(localdb)\ProjectsV13;Initial Catalog=master;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False

How to run multiple sites on one apache instance

Your question is mixing a few different concepts. You started out saying you wanted to run sites on the same server using the same domain, but in different folders. That doesn't require any special setup. Once you get the single domain running, you just create folders under that docroot.

Based on the rest of your question, what you really want to do is run various sites on the same server with their own domain names.

The best documentation you'll find on the topic is the virtual host documentation in the apache manual.

There are two types of virtual hosts: name-based and IP-based. Name-based allows you to use a single IP address, while IP-based requires a different IP for each site. Based on your description above, you want to use name-based virtual hosts.

The initial error you were getting was due to the fact that you were using different ports than the NameVirtualHost line. If you really want to have sites served from ports other than 80, you'll need to have a NameVirtualHost entry for each port.

Assuming you're starting from scratch, this is much simpler than it may seem.

If you are using 2.3 or earlier, the first thing you need to do is tell Apache that you're going to use name-based virtual hosts.

NameVirtualHost *:80

If you are using 2.4 or later do not add a NameVirtualHost line. Version 2.4 of Apache deprecated the NameVirtualHost directive, and it will be removed in a future version.

Now your vhost definitions:

<VirtualHost *:80>
    DocumentRoot "/home/user/site1/"
    ServerName site1
</VirtualHost>

<VirtualHost *:80>
    DocumentRoot "/home/user/site2/"
    ServerName site2
</VirtualHost>

You can run as many sites as you want on the same port. The ServerName being different is enough to tell Apache which vhost to use. Also, the ServerName directive is always the domain/hostname and should never include a path.

If you decide to run sites on a port other than 80, you'll always have to include the port number in the URL when accessing the site. So instead of going to http://example.com you would have to go to http://example.com:81

Why do we assign a parent reference to the child object in Java?

First, a clarification of terminology: we are assigning a Child object to a variable of type Parent. Parent is a reference to an object that happens to be a subtype of Parent, a Child.

It is only useful in a more complicated example. Imagine you add getEmployeeDetails to the class Parent:

public String getEmployeeDetails() {
    return "Name: " + name;
}

We could override that method in Child to provide more details:

@Override
public String getEmployeeDetails() {
    return "Name: " + name + " Salary: " + salary;
}

Now you can write one line of code that gets whatever details are available, whether the object is a Parent or Child:

parent.getEmployeeDetails();

The following code:

Parent parent = new Parent();
parent.name = 1;
Child child = new Child();
child.name = 2;
child.salary = 2000;
Parent[] employees = new Parent[] { parent, child };
for (Parent employee : employees) {
    employee.getEmployeeDetails();
}

Will result in the output:

Name: 1
Name: 2 Salary: 2000

We used a Child as a Parent. It had specialized behavior unique to the Child class, but when we called getEmployeeDetails() we could ignore the difference and focus on how Parent and Child are similar. This is called subtype polymorphism.

Your updated question asks why Child.salary is not accessible when the Childobject is stored in a Parent reference. The answer is the intersection of "polymorphism" and "static typing". Because Java is statically typed at compile time you get certain guarantees from the compiler but you are forced to follow rules in exchange or the code won't compile. Here, the relevant guarantee is that every instance of a subtype (e.g. Child) can be used as an instance of its supertype (e.g. Parent). For instance, you are guaranteed that when you access employee.getEmployeeDetails or employee.name the method or field is defined on any non-null object that could be assigned to a variable employee of type Parent. To make this guarantee, the compiler considers only that static type (basically, the type of the variable reference, Parent) when deciding what you can access. So you cannot access any members that are defined on the runtime type of the object, Child.

When you truly want to use a Child as a Parent this is an easy restriction to live with and your code will be usable for Parent and all its subtypes. When that is not acceptable, make the type of the reference Child.

Call Activity method from adapter

In Kotlin there is now a cleaner way by using lambda functions, no need for interfaces:

class MyAdapter(val adapterOnClick: (Any) -> Unit) {
    fun setItem(item: Any) {
        myButton.setOnClickListener { adapterOnClick(item) }
    }
}

class MyActivity {
    override fun onCreate(savedInstanceState: Bundle?) {
        var myAdapter = MyAdapter { item -> doOnClick(item) }
    }


    fun doOnClick(item: Any) {

    }
}

Abstraction vs Encapsulation in Java

In simple words: You do abstraction when deciding what to implement. You do encapsulation when hiding something that you have implemented.

nginx error "conflicting server name" ignored

You have another server_name ec2-xx-xx-xxx-xxx.us-west-1.compute.amazonaws.com somewhere in the config.

Using scp to copy a file to Amazon EC2 instance?

First you should change the mode of .pem file from read and write mode to read only mode. This can be done just by a single command in terminal sudo chmod 400 your_public_key.pem

How to get the caller class in Java

Since I currently have the same problem here is what I do:

  1. I prefer com.sun.Reflection instead of stackTrace since a stack trace is only producing the name not the class (including the classloader) itself.

  2. The method is deprecated but still around in Java 8 SDK.

// Method descriptor #124 (I)Ljava/lang/Class; (deprecated) // Signature: (I)Ljava/lang/Class<*>; @java.lang.Deprecated public static native java.lang.Class getCallerClass(int arg0);

  1. The method without int argument is not deprecated

// Method descriptor #122 ()Ljava/lang/Class; // Signature: ()Ljava/lang/Class<*>; @sun.reflect.CallerSensitive public static native java.lang.Class getCallerClass();

Since I have to be platform independent bla bla including Security Restrictions, I just create a flexible method:

  1. Check if com.sun.Reflection is available (security exceptions disable this mechanism)

  2. If 1 is yes then get the method with int or no int argument.

  3. If 2 is yes call it.

If 3. was never reached, I use the stack trace to return the name. I use a special result object that contains either the class or the string and this object tells exactly what it is and why.

[Summary] I use stacktrace for backup and to bypass eclipse compiler warnings I use reflections. Works very good. Keeps the code clean, works like a charm and also states the problems involved correctly.

I use this for quite a long time and today I searched a related question so

Enable remote connections for SQL Server Express 2012

One More Thing...

Kyralessa provides great information but I have one other thing to add where I was stumped even after this article.

Under SQL Server Network Configuration > Protocols for Server > TCP/IP Enabled. Right Click TCP/IP and choose properties. Under the IP Addresses you need to set Enabled to Yes for each connection type that you are using.

enter image description here

Private pages for a private Github repo

So sad It's 2020 and we are not able to have private GithubPäges:

enter image description here

NoSQL Use Case Scenarios or WHEN to use NoSQL

I think Nosql is "more suitable" in these scenarios at least (more supplementary is welcome)

  1. Easy to scale horizontally by just adding more nodes.

  2. Query on large data set

    Imagine tons of tweets posted on twitter every day. In RDMS, there could be tables with millions (or billions?) of rows, and you don't want to do query on those tables directly, not even mentioning, most of time, table joins are also needed for complex queries.

  3. Disk I/O bottleneck

    If a website needs to send results to different users based on users' real-time info, we are probably talking about tens or hundreds of thousands of SQL read/write requests per second. Then disk i/o will be a serious bottleneck.

scp with port number specified

To backup all files in all directories to a remote Synology NAS using a different remote port:

scp -P 10022 -r /media/data/somedata/* [email protected]:/var/services/homes/user/directory/

Are static methods inherited in Java?

This concept is not that easy as it looks. We can access static members without inheritance, which is HasA-relation. We can access static members by extending the parent class also. That doesn't imply that it is an ISA-relation (Inheritance). Actually static members belong to the class, and static is not an access modifier. As long as the access modifiers permit to access the static members we can use them in other classes. Like if it is public then it will be accessible inside the same package and also outside the package. For private we can't use it anywhere. For default, we can use it only within the package. But for protected we have to extend the super class. So getting the static method to other class does not depend on being Static. It depends on Access modifiers. So, in my opinion, Static members can access if the access modifiers permit. Otherwise, we can use them like we use by Hasa-relation. And has a relation is not inheritance. Again we can not override the static method. If we can use other method but cant override it, then it is HasA-relation. If we can't override them it won't be inheritance.So the writer was 100% correct.

Allow all remote connections, MySQL

Install and setup mysql to connect from anywhere remotely DOES NOT WORK WITH mysql_secure_installation ! (https://dev.mysql.com/doc/refman/5.5/en/mysql-secure-installation.html)

On Ubuntu, Install mysql using:

sudo apt-get install mysql-server

Have just the below in /etc/mysql/my.cnf

[mysqld]
#### Unix socket settings (making localhost work)
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock

#### TCP Socket settings (making all remote logins work)
port            = 3306
bind-address = 0.0.0.0

Login into DB from server using

mysql -u root -p

Create DB user using the below statement

grant all privileges on *.* to ‘username’@‘%’ identified by ‘password’;

Open firewall:

sudo ufw allow 3306

Restart mysql

sudo service mysql restart

Global Variable in app.js accessible in routes?

This was a helpful question, but could be more so by giving actual code examples. Even the linked article does not actually show an implementation. I, therefore, humbly submit:

In your app.js file, the top of the file:

var express = require('express')
, http = require('http')
, path = require('path');

app = express(); //IMPORTANT!  define the global app variable prior to requiring routes!

var routes = require('./routes');

app.js will not have any reference to app.get() method. Leave these to be defined in the individual routes files.

routes/index.js:

require('./main');
require('./users');

and finally, an actual routes file, routes/main.js:

function index (request, response) {
    response.render('index', { title: 'Express' });
}

app.get('/',index); // <-- define the routes here now, thanks to the global app variable

How to specify 64 bit integers in c

Append ll suffix to hex digits for 64-bit (long long int), or ull suffix for unsigned 64-bit (unsigned long long)

The source was not found, but some or all event logs could not be searched

If you just want to sniff if a Source exists on the local machine but don't have ability to get authorization to do this, you can finger it through the following example (VB).

This bypasses the security error. You could similarly modify this function to return the LogName for the Source.

Public Shared Function eventLogSourceExists(sSource as String) as Boolean
    Try
        EventLog.LogNameFromSourceName(sSource, ".")
        Return True
    Catch
        Return False
    End Try
End Function

Java - No enclosing instance of type Foo is accessible

Thing is an inner class with an automatic connection to an instance of Hello. You get a compile error because there is no instance of Hello for it to attach to. You can fix it most easily by changing it to a static nested class which has no connection:

static class Thing

Check whether a path is valid in Python without creating a file at the path's target

open(filename,'r')   #2nd argument is r and not w

will open the file or give an error if it doesn't exist. If there's an error, then you can try to write to the path, if you can't then you get a second error

try:
    open(filename,'r')
    return True
except IOError:
    try:
        open(filename, 'w')
        return True
    except IOError:
        return False

Also have a look here about permissions on windows

ssh "permissions are too open" error

Windows 10 ssh into Ubuntu EC2 “permissions are too open” error on AWS

I had this issue trying to ssh into an Ubuntu EC2 instance using the .pem file from AWS.

In windows this worked when I put this key in a folder created under the .ssh folder

C:\Users\USERNAME\.ssh\private_key

To change permission settings in Windows 10 :

File Settings > Security > Advanced

Disable inheritance

Convert Inherited Permissions Into Explicit Permissions

Remove all the permission entries except for Administrators

Could then connect securely.

Access restriction: Is not accessible due to restriction on required library ..\jre\lib\rt.jar

In Eclipse:
Project -> properties -> java Build Path -> libraries

Remove existing JRE System Library, then Add Library -> JRE System library -> next -> ok

Error will be removed.

configure Git to accept a particular self-signed server certificate for a particular https remote

OSX User adjustments.

Following the steps of the Accepted answer worked for me with a small addition when configuring on OSX.

I put the cert.pem file in a directory under my OSX logged in user and thus caused me to adjust the location for the trusted certificate.

Configure git to trust this certificate:

$ git config --global http.sslCAInfo $HOME/git-certs/cert.pem

How to pass macro definition from "make" command line arguments (-D) to C source code?

$ cat x.mak
all:
    echo $(OPTION)
$ make -f x.mak 'OPTION=-DPASSTOC=42'
echo -DPASSTOC=42
-DPASSTOC=42

Is there any publicly accessible JSON data source to test with real world data?

Tumblr has a public API that provides JSON. You can get a dump of posts using a simple url like http://puppygifs.tumblr.com/api/read/json.

Trying to SSH into an Amazon Ec2 instance - permission error

Well, looking at your post description I feel there were 2 mistakes done by you:-

  1. Set correct permissions for the private key. Below command should help you to set correct file permision.

    chmod 0600 mykey.pem

  2. Wrong ec2 user you are trying to login.

    Looking at your debug log I think you have spawned an Amazon linux instance. The default user for that instance type is ec2-user . If the instance would have been ubuntu then your default user would have been ubuntu .

    ssh -i privatekey.pem default_ssh_user@server_ip

Note:
   For an Amazon Linux AMI, the default user name is ec2-user.

   For a Centos AMI, the default user name is centos.

   For a Debian AMI, the default user name is admin or root.

   For a Fedora AMI, the default user name is ec2-user or fedora.

   For a RHEL AMI, the default user name is ec2-user or root.

   For a SUSE AMI, the default user name is ec2-user or root.

   For an Ubuntu AMI, the default user name is ubuntu.

   Otherwise, if ec2-user and root don't work, check with the AMI provider.

source: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html

Using C++ base class constructors?

No, that's not how it is done. Normal way to initialize the base class is in the initialization list :

class A
{
public: 
    A(int val) {}
};

class B : public A
{
public:
  B( int v) : A( v )
  {
  }
};


void main()
{
    B b(10);
}

PHP JSON String, escape Double Quotes for JS output

Error come on script not in HTML tags.

<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<pre><?php print_r($_POST??'') ?></pre>

<form method="POST">
    <input type="text" name="name"><br>
    <input type="email" name="email"><br>
    <input type="time" name="time"><br>
    <input type="date" name="date"><br>
    <input type="hidden" name="id"><br>
    <textarea name="detail"></textarea>
    <input type="submit" value="Submit"><br>
</form>
<?php 
/* data */
$data = [
            'name'=>'loKESH"'."'\\\\",
            'email'=>'[email protected]',
            'time'=>date('H:i:00'),
            'date'=>date('Y-m-d'),
            'detail'=>'Try this var_dump(0=="ZERO") \\ \\"'." ' \\\\    ",
            'id'=>123,
        ];
?>
<span style="display: none;" class="ajax-data"><?=json_encode($_POST??$data)?></span>
<script type="text/javascript">
    /* Error */
    // var json = JSON.parse('<?=json_encode($data)?>');
    /* Error solved */
    var json = JSON.parse($('.ajax-data').html());
    console.log(json)
    /* automatically assigned value by name attr */
    for(x in json){
        $('[name="'+x+'"]').val(json[x]);
    }
</script>

How to len(generator())

You can use len(list(generator_function()). However, this consumes the generator, but that's the only way you can find out how many elements are generated. So you may want to save the list somewhere if you also want to use the items.

a = list(generator_function())
print(len(a))
print(a[0])

How permission can be checked at runtime without throwing SecurityException?

This is another solution as well

PackageManager pm = context.getPackageManager();
int hasPerm = pm.checkPermission(
    android.Manifest.permission.WRITE_EXTERNAL_STORAGE, 
    context.getPackageName());
if (hasPerm != PackageManager.PERMISSION_GRANTED) {
   // do stuff
}

How do I resolve "Please make sure that the file is accessible and that it is a valid assembly or COM component"?

Look here for the answer by TheMattster. I implemented it and it worked like a charm. In a nutshell, his solution suggests to add the COM dll as a resource to the project (so now it compiles into the project's dll), and upon the first run write it to a file (i.e. the dll file I wanted there in the first place).

The following is taken from his answer.

Step 1) Add the DLL as a resource (below as "Resources.DllFile"). To do this open project properties, select the resources tab, select "add existing file" and add the DLL as a resource.

Step 2) Add the name of the DLL as a string resource (below as "Resources.DllName").

Step 3) Add this code to your main form-load:

if (!File.Exists(Properties.Resources.DllName))
{
    var outStream = new StreamWriter(Properties.Resources.DllName, false);
    var binStream = new BinaryWriter(outStream.BaseStream);
    binStream.Write(Properties.Resources.DllFile);
    binStream.Close();
}

My problem was that not only I had to use the COM dll in my project, I also had to deploy it with my app using ClickOnce, and without being able to add reference to it in my project the above solution is practically the only one that worked.

Is there a way to get a list of all current temporary tables in SQL Server?

You can get list of temp tables by following query :

select left(name, charindex('_',name)-1) 
from tempdb..sysobjects
where charindex('_',name) > 0 and
xtype = 'u' and not object_id('tempdb..'+name) is null

Unable to connect to SQL Server instance remotely

If you have more than one Instances... Then make sure the PORT Numbers of all Instances are Unique and no one's PORT Number is 1433 except Default One...

Converting Integer to Long

If you don't know the exact class of your number (Integer, Long, Double, whatever), you can cast to Number and get your long value from it:

Object num = new Integer(6);
Long longValue = ((Number) num).longValue();

How to pass parameters to a partial view in ASP.NET MVC?

Following is working for me on dotnet 1.0.1:

./ourView.cshtml

@Html.Partial(
  "_ourPartial.cshtml",
  new ViewDataDictionary(this.Vi??ewData) {
    {
      "hi", "hello" 
    } 
  }
);

./_ourPartial.cshtml

<h1>@this.ViewData["hi"]</h1>

Unable to connect to SQL Express "Error: 26-Error Locating Server/Instance Specified)

I recently encountered the same issue however I am using Windows 10 Technical Preview Build 10041 and SQL Server 2014 (Advanced).

Follow the same advice from above:

In particular, my problem was that I did not enable the TCP/IP in Sql Server Configuration Manager->SQL Server Network Configuration->Protocols for SQLEXPRESS.

Once you open it, you have to go to the IP Addresses tab and for me, changing IPAll to TCP port 1433 and deleting the TCP Dynamic Ports value worked.

Follow the other steps to make sure 1433 is listening (Use netstat -an to make sure 0.0.0.0:1433 is LISTENING.), and that you can telnet to the port from the client machine.

Finally, I second the suggestion to remove the \SQLEXPRESS from the connection.

AND ----> That last line is important! It looks like to be Windows 10 specific; remove \SQLEXPRESS from your connection string. What was frusting was that SQL Management Studio connects just fine using either connection string (full or short), however Visual Studio only accepted the connection string without the \SQLEXPRESS.

Can a local variable's memory be accessed outside its scope?

You never throw a C++ exception by accessing invalid memory. You are just giving an example of the general idea of referencing an arbitrary memory location. I could do the same like this:

unsigned int q = 123456;

*(double*)(q) = 1.2;

Here I am simply treating 123456 as the address of a double and write to it. Any number of things could happen:

  1. q might in fact genuinely be a valid address of a double, e.g. double p; q = &p;.
  2. q might point somewhere inside allocated memory and I just overwrite 8 bytes in there.
  3. q points outside allocated memory and the operating system's memory manager sends a segmentation fault signal to my program, causing the runtime to terminate it.
  4. You win the lottery.

The way you set it up it is a bit more reasonable that the returned address points into a valid area of memory, as it will probably just be a little further down the stack, but it is still an invalid location that you cannot access in a deterministic fashion.

Nobody will automatically check the semantic validity of memory addresses like that for you during normal program execution. However, a memory debugger such as valgrind will happily do this, so you should run your program through it and witness the errors.

Inconsistent Accessibility: Parameter type is less accessible than method

Constructor of public class clients is public but it has a parameter of type ACTInterface that is private (it is nested in a class?). You can't do that. You need to make ACTInterface at least as accessible as clients.

Check whether a path is valid

The closest I have come is by trying to create it, and seeing if it succeeds.

is inaccessible due to its protection level

Dan, it's just you're accessing the protected field instead of properties.

See for example this line in your Main(...):

myClub.distance = Console.ReadLine();

myClub.distance is the protected field, while you wanted to set the property mydistance.

I'm just giving you some hint, I'm not going to correct your code, since this is homework! ;)

Call a python function from jinja2

For those using Flask, put this in your __init__.py:

def clever_function():
    return u'HELLO'

app.jinja_env.globals.update(clever_function=clever_function)

and in your template call it with {{ clever_function() }}

Show / hide div on click with CSS

You could do this with the CSS3 :target selector.

menu:hover block {
    visibility: visible;
}

block:target {
    visibility:hidden;
}

How to SSH to a VirtualBox guest externally through a host?

A good explanation about how to configure port forwarding with NAT is found in the VirtualBox documents: http://www.virtualbox.org/manual/ch06.html#natforward

Android: Getting a file URI from a content URI?

Try this....

get File from a content uri

fun fileFromContentUri(context: Context, contentUri: Uri): File {
    // Preparing Temp file name
    val fileExtension = getFileExtension(context, contentUri)
    val fileName = "temp_file" + if (fileExtension != null) ".$fileExtension" else ""

    // Creating Temp file
    val tempFile = File(context.cacheDir, fileName)
    tempFile.createNewFile()

    try {
        val oStream = FileOutputStream(tempFile)
        val inputStream = context.contentResolver.openInputStream(contentUri)

        inputStream?.let {
            copy(inputStream, oStream)
        }

        oStream.flush()
    } catch (e: Exception) {
        e.printStackTrace()
    }

    return tempFile
}

private fun getFileExtension(context: Context, uri: Uri): String? {
    val fileType: String? = context.contentResolver.getType(uri)
    return MimeTypeMap.getSingleton().getExtensionFromMimeType(fileType)
}

@Throws(IOException::class)
private fun copy(source: InputStream, target: OutputStream) {
    val buf = ByteArray(8192)
    var length: Int
    while (source.read(buf).also { length = it } > 0) {
        target.write(buf, 0, length)
    }
}

Difference between /res and /assets directories

Following are some key points :

  1. Raw files Must have names that are valid Java identifiers , whereas files in Assets Have no location and name restrictions. In other words they can be grouped in whatever directories we wish
  2. Raw files Are easy to refer to from Java as well as from xml (i.e you can refer a file in raw from manifest or other xml file).
  3. Saving asset files here instead of in the assets/ directory only differs in the way that you access them as documented here http://developer.android.com/tools/projects/index.html.
  4. Resources defined in a library project are automatically imported to application projects that depend on the library. For assets, that doesn't happen; asset files must be present in the assets directory of the application project(s)
  5. The assets directory is more like a filesystem provides more freedom to put any file you would like in there. You then can access each of the files in that system as you would when accessing any file in any file system through Java . like Game data files , Fonts , textures etc.
  6. Unlike Resources, Assets can can be organized into subfolders in the assets directory However, the only thing you can do with an asset is get an input stream. Thus, it does not make much sense to store your strings or bitmaps in assets, but you can store custom-format data such as input correction dictionaries or game maps.
  7. Raw can give you a compile time check by generating your R.java file however If you want to copy your database to private directory you can use Assets which are made for streaming.

Conclusion

  1. Android API includes a very comfortable Resources framework that is also optimized for most typical use cases for various mobile apps. You should master Resources and try to use them wherever possible.
  2. However, if you need more flexibility for your special case, Assets are there to give you a lower level API that allows organizing and processing your resources with a higher degree of freedom.

How to pass a Javascript Array via JQuery Post so that all its contents are accessible via the PHP $_POST array?

If you want to pass a JavaScript object/hash (ie. an associative array in PHP) then you would do:

$.post('/url/to/page', {'key1': 'value', 'key2': 'value'});

If you wanna pass an actual array (ie. an indexed array in PHP) then you can do:

$.post('/url/to/page', {'someKeyName': ['value','value']});

If you want to pass a JavaScript array then you can do:

$.post('/url/to/page', {'someKeyName': variableName});

import sun.misc.BASE64Encoder results in error compiled in Eclipse

This error is because of you are importing below two classes import sun.misc.BASE64Encoder; import sun.misc.BASE64Decoder;. Maybe you are using encode and decode of that library like below.

new BASE64Encoder().encode(encVal);
newBASE64Decoder().decodeBuffer(encryptedData);

Yeah instead of sun.misc.BASE64Encoder you can import java.util.Base64 class.Now change the previous encode method as below:

encryptedData=Base64.getEncoder().encodeToString(encryptedByteArray);

Now change the previous decode method as below

byte[] base64DecodedData = Base64.getDecoder().decode(base64EncodedData);

Now everything is done , you can save your program and run. It will run without showing any error.

How do I set up cron to run a file just once at a specific time?

You really want to use at. It is exactly made for this purpose.

echo /usr/bin/the_command options | at now + 1 day

However if you don't have at, or your hosting company doesn't provide access to it, you can have a cron job include code that makes sure it only runs once.

Set up a cron entry with a very specific time:

0 0 2 12 * /home/adm/bin/the_command options

Next /home/adm/bin/the_command needs to either make sure it only runs once.

#! /bin/bash

COMMAND=/home/adm/bin/the_command
DONEYET="${COMMAND}.alreadyrun"

export PATH=/usr/bin:$PATH

if [[ -f $DONEYET ]]; then
  exit 1
fi
touch "$DONEYET"

# Put the command you want to run exactly once here:
echo 'You will only get this once!' | mail -s 'Greetings!' [email protected]

Failed to add a service. Service metadata may not be accessible. Make sure your service is running and exposing metadata.`

After Add this to your web.config file and configure according to your service name and contract name.

<behaviors>
   <serviceBehaviors>
      <behavior name="metadataBehavior">
         <serviceMetadata httpGetEnabled="true" />
      </behavior>
   </serviceBehaviors>
</behaviors>
<services>
   <service name="MyService.MyService" behaviorConfiguration="metadataBehavior">
      <endpoint 
          address=""   <!-- don't put anything here - Cassini will determine address -->
          binding="basicHttpBinding" 
          contract="MyService.IMyService"/>
      <endpoint 
          address="mex" 
          binding="mexHttpBinding" 
          contract="IMetadataExchange"/>
   </service>
</services>

Please add this in your Service.svc

using System.ServiceModel.Description;

Hope it will helps you.

C++ inheritance - inaccessible base?

You have to do this:

class Bar : public Foo
{
    // ...
}

The default inheritance type of a class in C++ is private, so any public and protected members from the base class are limited to private. struct inheritance on the other hand is public by default.

"Register" an .exe so you can run it from any command line in Windows

It is very simple and it won't take more than 30 seconds.

For example the software called abc located in D:/Softwares/vlc/abc.exe Add the folder path of abc.exe to system environment variables.

My Computer -> Click Properties -> Click Advanced system settings -> Click Environment Variables

enter image description here

enter image description here

Click on Ok.

now you can just open cmd prompt and you can launch the software from anywhere. to use abc.exe just type abc in the command line.

Cannot connect to local SQL Server with Management Studio

Try to see, if the service "SQL Server (MSSQLSERVER)" it's started, this solved my problem.

Pass connection string to code-first DbContext

In your DbContext, create a default constructor for your DbContext and inherit the base like this:

    public myDbContext()
        : base("MyConnectionString")  // connectionstring name define in your web.config
    {
    }

Why are only final variables accessible in anonymous class?

private void f(Button b, final int a[]) {

    b.addClickHandler(new ClickHandler() {

        @Override
        public void onClick(ClickEvent event) {
            a[0] = a[0] * 5;

        }
    });
}

Declare global variables in Visual Studio 2010 and VB.NET

Okay. I finally found what actually works to answer the question that seems to be asked;

"When needing many modules and forms, how can I declare a variable to be public to all of them such that they each reference the same variable?"

Amazingly to me, I spent considerable time searching the web for that seemingly simple question, finding nothing but vagueness that left me still getting errors.

But thanks to Cody Gray's link to an example, I was able to discern a proper answer;


Situation; You have multiple Modules and/or Forms and want to reference a particular variable from each or all.

"A" way that works; On one module place the following code (wherein "DefineGlobals" is an arbitrarily chosen name);

Public Module DefineGlobals

Public Parts As Integer                 'Assembled-particle count
Public FirstPrtAff As Long              'Addr into Link List 
End Module

And then in each Module/Form in need of addressing that variable "Parts", place the following code (as an example of the "InitForm2" form);

Public Class InitForm2
Private Sub InitForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    Parts = Parts + 3

End Sub

End Class

And perhaps another Form; Public Class FormX

Sub CreateAff()

   Parts = 1000

End Sub 

 End Class

That type of coding seems to have worked on my VB2008 Express and seems to be all needed at the moment (void of any unknown files being loaded in the background) even though I have found no end to the "Oh btw..." surprise details. And I'm certain a greater degree of standardization would be preferred, but the first task is simply to get something working at all, with or without standards.

Nothing beats exact and well worded, explicit examples.

Thanks again, Cody

brew install mysql on macOS

TL;DR

MySQL server might not be running after installation with Brew. Try brew services start mysql or just mysql.server start if you don't want MySQL to run as a background service.

Full Story:

I just installed MySQL (stable) 5.7.17 on a new MacBook Pro running Sierra and also got an error when running mysql_secure_installation:

Securing the MySQL server deployment.

Enter password for user root: 
Error: Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

Say what?

According to the installation info from Brew, mysql_secure_installation should prompt me to... secure the installation. I figured the MySQL server might not be running and rightly so. Running brew services start mysql and then mysql_secure_installation worked like a charm.

Work on a remote project with Eclipse via SSH

This answer currently only applies to using two Linux computers [or maybe works on Mac too?--untested on Mac] (syncing from one to the other) because I wrote this synchronization script in bash. It is simply a wrapper around git, however, so feel free to take it and convert it into a cross-platform Python solution or something if you wish


This doesn't directly answer the OP's question, but it is so close I guarantee it will answer many other peoples' question who land on this page (mine included, actually, as I came here first before writing my own solution), so I'm posting it here anyway.

I want to:

  1. develop code using a powerful IDE like Eclipse on a light-weight Linux computer, then
  2. build that code via ssh on a different, more powerful Linux computer (from the command-line, NOT from inside Eclipse)

Let's call the first computer where I write the code "PC1" (Personal Computer 1), and the 2nd computer where I build the code "PC2". I need a tool to easily synchronize from PC1 to PC2. I tried rsync, but it was insanely slow for large repos and took tons of bandwidth and data.

So, how do I do it? What workflow should I use? If you have this question too, here's the workflow that I decided upon. I wrote a bash script to automate the process by using git to automatically push changes from PC1 to PC2 via a remote repository, such as github. So far it works very well and I'm very pleased with it. It is far far far faster than rsync, more trustworthy in my opinion because each PC maintains a functional git repo, and uses far less bandwidth to do the whole sync, so it's easily doable over a cell phone hot spot without using tons of your data.

Setup:

  1. Install the script on PC1 (this solution assumes ~/bin is in your $PATH):

    git clone https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles.git
    cd eRCaGuy_dotfiles/useful_scripts
    mkdir -p ~/bin
    ln -s "${PWD}/sync_git_repo_from_pc1_to_pc2.sh" ~/bin/sync_git_repo_from_pc1_to_pc2
    cd ..
    cp -i .sync_git_repo ~/.sync_git_repo
    
  2. Now edit the "~/.sync_git_repo" file you just copied above, and update its parameters to fit your case. Here are the parameters it contains:

    # The git repo root directory on PC2 where you are syncing your files TO; this dir must *already exist* 
    # and you must have *already `git clone`d* a copy of your git repo into it!
    # - Do NOT use variables such as `$HOME`. Be explicit instead. This is because the variable expansion will 
    #   happen on the local machine when what we need is the variable expansion from the remote machine. Being 
    #   explicit instead just avoids this problem.
    PC2_GIT_REPO_TARGET_DIR="/home/gabriel/dev/eRCaGuy_dotfiles" # explicitly type this out; don't use variables
    
    PC2_SSH_USERNAME="my_username" # explicitly type this out; don't use variables
    PC2_SSH_HOST="my_hostname"     # explicitly type this out; don't use variables
    
  3. Git clone your repo you want to sync on both PC1 and PC2.

  4. Ensure your ssh keys are all set up to be able to push and pull to the remote repo from both PC1 and PC2. Here's some helpful links:
    1. https://help.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh
    2. https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent
  5. Ensure your ssh keys are all set up to ssh from PC1 to PC2.
  6. Now cd into any directory within the git repo on PC1, and run:

    sync_git_repo_from_pc1_to_pc2
    
  7. That's it! About 30 seconds later everything will be magically synced from PC1 to PC2, and it will be printing output the whole time to tell you what it's doing and where it's doing it on your disk and on which computer. It's safe too, because it doesn't overwrite or delete anything that is uncommitted. It backs it up first instead! Read more below for how that works.

Here's the process this script uses (ie: what it's actually doing)

  1. From PC1: It checks to see if any uncommitted changes are on PC1. If so, it commits them to a temporary commit on the current branch. It then force pushes them to a remote SYNC branch. Then it uncommits its temporary commit it just did on the local branch, then it puts the local git repo back to exactly how it was by staging any files that were previously staged at the time you called the script. Next, it rsyncs a copy of the script over to PC2, and does an ssh call to tell PC2 to run the script with a special option to just do PC2 stuff.
  2. Here's what PC2 does: it cds into the repo, and checks to see if any local uncommitted changes exist. If so, it creates a new backup branch forked off of the current branch (sample name: my_branch_SYNC_BAK_20200220-0028hrs-15sec <-- notice that's YYYYMMDD-HHMMhrs--SSsec), and commits any uncommitted changes to that branch with a commit message such as DO BACKUP OF ALL UNCOMMITTED CHANGES ON PC2 (TARGET PC/BUILD MACHINE). Now, it checks out the SYNC branch, pulling it from the remote repository if it is not already on the local machine. Then, it fetches the latest changes on the remote repository, and does a hard reset to force the local SYNC repository to match the remote SYNC repository. You might call this a "hard pull". It is safe, however, because we already backed up any uncommitted changes we had locally on PC2, so nothing is lost!
  3. That's it! You now have produced a perfect copy from PC1 to PC2 without even having to ensure clean working directories, as the script handled all of the automatic committing and stuff for you! It is fast and works very well on huge repositories. Now you have an easy mechanism to use any IDE of your choice on one machine while building or testing on another machine, easily, over a wifi hot spot from your cell phone if needed, even if the repository is dozens of gigabytes and you are time and resource-constrained.

Resources:

  1. The whole project: https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles
    1. See tons more links and references in the source code itself within this project.
  2. How to do a "hard pull", as I call it: How do I force "git pull" to overwrite local files?

Related:

  1. git repository sync between computers, when moving around?

Best Way to Refresh Adapter/ListView on Android

Simply add these code before setting Adapter it's working for me:

    listView.destroyDrawingCache();
    listView.setVisibility(ListView.INVISIBLE);
    listView.setVisibility(ListView.VISIBLE);

Or Directly you can use below method after change Data resource.

   adapter.notifyDataSetChanged()

jQuery how to find an element based on a data-attribute value?

I improved upon psycho brm's filterByData extension to jQuery.

Where the former extension searched on a key-value pair, with this extension you can additionally search for the presence of a data attribute, irrespective of its value.

(function ($) {

    $.fn.filterByData = function (prop, val) {
        var $self = this;
        if (typeof val === 'undefined') {
            return $self.filter(
                function () { return typeof $(this).data(prop) !== 'undefined'; }
            );
        }
        return $self.filter(
            function () { return $(this).data(prop) == val; }
        );
    };

})(window.jQuery);

Usage:

$('<b>').data('x', 1).filterByData('x', 1).length    // output: 1
$('<b>').data('x', 1).filterByData('x').length       // output: 1

_x000D_
_x000D_
// test data_x000D_
function extractData() {_x000D_
  log('data-prop=val ...... ' + $('div').filterByData('prop', 'val').length);_x000D_
  log('data-prop .......... ' + $('div').filterByData('prop').length);_x000D_
  log('data-random ........ ' + $('div').filterByData('random').length);_x000D_
  log('data-test .......... ' + $('div').filterByData('test').length);_x000D_
  log('data-test=anyval ... ' + $('div').filterByData('test', 'anyval').length);_x000D_
}_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $('#b5').data('test', 'anyval');_x000D_
});_x000D_
_x000D_
// the actual extension_x000D_
(function($) {_x000D_
_x000D_
  $.fn.filterByData = function(prop, val) {_x000D_
    var $self = this;_x000D_
    if (typeof val === 'undefined') {_x000D_
      return $self.filter(_x000D_
_x000D_
        function() {_x000D_
          return typeof $(this).data(prop) !== 'undefined';_x000D_
        });_x000D_
    }_x000D_
    return $self.filter(_x000D_
_x000D_
      function() {_x000D_
        return $(this).data(prop) == val;_x000D_
      });_x000D_
  };_x000D_
_x000D_
})(window.jQuery);_x000D_
_x000D_
_x000D_
//just to quickly log_x000D_
function log(txt) {_x000D_
  if (window.console && console.log) {_x000D_
    console.log(txt);_x000D_
    //} else {_x000D_
    //  alert('You need a console to check the results');_x000D_
  }_x000D_
  $("#result").append(txt + "<br />");_x000D_
}
_x000D_
#bPratik {_x000D_
  font-family: monospace;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
_x000D_
<div id="bPratik">_x000D_
  <h2>Setup</h2>_x000D_
  <div id="b1" data-prop="val">Data added inline :: data-prop="val"</div>_x000D_
  <div id="b2" data-prop="val">Data added inline :: data-prop="val"</div>_x000D_
  <div id="b3" data-prop="diffval">Data added inline :: data-prop="diffval"</div>_x000D_
  <div id="b4" data-test="val">Data added inline :: data-test="val"</div>_x000D_
  <div id="b5">Data will be added via jQuery</div>_x000D_
  <h2>Output</h2>_x000D_
  <div id="result"></div>_x000D_
_x000D_
  <hr />_x000D_
  <button onclick="extractData()">Reveal</button>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Or the fiddle: http://jsfiddle.net/PTqmE/46/

Ruby on Rails: Where to define global constants?

If your model is really "responsible" for the constants you should stick them there. You can create class methods to access them without creating a new object instance:

class Card < ActiveRecord::Base
  def self.colours
    ['white', 'blue']
  end
end

# accessible like this
Card.colours

Alternatively, you can create class variables and an accessor. This is however discouraged as class variables might act kind of surprising with inheritance and in multi-thread environments.

class Card < ActiveRecord::Base
  @@colours = ['white', 'blue'].freeze
  cattr_reader :colours
end

# accessible the same as above
Card.colours

The two options above allow you to change the returned array on each invocation of the accessor method if required. If you have true a truly unchangeable constant, you can also define it on the model class:

class Card < ActiveRecord::Base
  COLOURS = ['white', 'blue'].freeze
end

# accessible as
Card::COLOURS

You could also create global constants which are accessible from everywhere in an initializer like in the following example. This is probably the best place, if your colours are really global and used in more than one model context.

# put this into config/initializers/my_constants.rb
COLOURS = ['white', 'blue'].freeze

# accessible as a top-level constant this time
COLOURS

Note: when we define constants above, often we want to freeze the array. That prevents other code from later (inadvertently) modifying the array by e.g. adding a new element. Once an object is frozen, it can't be changed anymore.

use localStorage across subdomains

I suggest making site.com redirect to www.site.com for both consistency and for avoiding issues like this.

Also, consider using a cross-browser solution like PersistJS that can use each browser native storage.

Rotating videos with FFmpeg

Rotate 90 clockwise:

ffmpeg -i in.mov -vf "transpose=1" out.mov

For the transpose parameter you can pass:

0 = 90CounterCLockwise and Vertical Flip (default)
1 = 90Clockwise
2 = 90CounterClockwise
3 = 90Clockwise and Vertical Flip

Use -vf "transpose=2,transpose=2" for 180 degrees.

Make sure you use a recent ffmpeg version from here (a static build will work fine).

Note that this will re-encode the audio and video parts. You can usually copy the audio without touching it, by using -c:a copy. To change the video quality, set the bitrate (for example with -b:v 1M) or have a look at the H.264 encoding guide if you want VBR options.

A solution is also to use this convenience script.

How can I make a horizontal ListView in Android?

Have you looked into the ViewFlipper component? Maybe it can help you.

http://developer.android.com/reference/android/widget/ViewFlipper.html

With this component, you can attach two or more view childs. If you add some translate animation and capture Gesture detection, you can have a nicely horizontal scroll.

Java time-based map/cache with expiring keys

If anybody needs a simple thing, following is a simple key-expiring set. It might be converted to a map easily.

public class CacheSet<K> {
    public static final int TIME_OUT = 86400 * 1000;

    LinkedHashMap<K, Hit> linkedHashMap = new LinkedHashMap<K, Hit>() {
        @Override
        protected boolean removeEldestEntry(Map.Entry<K, Hit> eldest) {
            final long time = System.currentTimeMillis();
            if( time - eldest.getValue().time > TIME_OUT) {
                Iterator<Hit> i = values().iterator();

                i.next();
                do {
                    i.remove();
                } while( i.hasNext() && time - i.next().time > TIME_OUT );
            }
            return false;
        }
    };


    public boolean putIfNotExists(K key) {
        Hit value = linkedHashMap.get(key);
        if( value != null ) {
            return false;
        }

        linkedHashMap.put(key, new Hit());
        return true;
    }

    private static class Hit {
        final long time;


        Hit() {
            this.time = System.currentTimeMillis();
        }
    }
}

php error: Class 'Imagick' not found

Ubuntu

sudo apt-get install php5-dev pecl imagemagick libmagickwand-dev
sudo pecl install imagick
sudo apt-get install php5-imagick
sudo service apache2 restart

Some dependencies will probably already be met but excluding the Apache service, that's everything required for PHP to use the Imagick class.

Class is inaccessible due to its protection level

Try adding the below code to the class that you want to use

[Serializable()]
public partial class Class
{

A reference to the dll could not be added

Make sure your compiler is set to x86 if you are trying to reference an x86 dll...

I was having similar issues... as mentioned above, trying to use OLEDB to access an Excel file from my C# code in Visual Studio 2012.

I kept getting errors about the Access library not being accessible but I knew that I had loaded it.

During Debug, it dawned on me that I am compiling for 64 bit but have Office x86 loaded. Even though I loaded the Access library for 32 bit, it was never being used by the app... and was, therefore, not accessible.

Here is what I was using in C#:

"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strFilePath + ";Extended Properties='Excel 12.0 Xml;HDR=Yes'";

...I was getting an error

As soon as I switched the compiler to x86 it worked

TCPDF not render all CSS properties

At the moment I write this, TCPDF only supports padding for tables.

Link to their forum page with that information

Change private static final field using Java reflection

Many of the answers here are useful, but I've found none of them to work on Android, in particular. I'm even a pretty hefty user of Reflect by joor, and neither it nor apache's FieldUtils - both mentioned here in some of the answers, do the trick.

Problem with Android

The fundamental reason why this is so is because on Android there's no modifiers field in the Field class, which renders any suggestion involving this code (as in the marked answer), useless:

Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);

In fact, to quote from FieldUtils.removeFinalModifier():

// Do all JREs implement Field with a private ivar called "modifiers"?
final Field modifiersField = Field.class.getDeclaredField("modifiers");

So, the answer is no...

Solution

Pretty easy - instead of modifiers, the field name is accessFlags. This does the trick:

Field accessFlagsField = Field.class.getDeclaredField("accessFlags");
accessFlagsField.setAccessible(true);
accessFlagsField.setInt(field, field.getModifiers() & ~Modifier.FINAL);

Side-note #1: this can work regardless of whether the field is static in the class, or not.

Side-note #2: Seeing that the field itself could be private, it's recommended to also enable access over the field itself, using field.setAccessible(true) (in addition to accessFlagsField.setAccessible(true).

Multiple GitHub Accounts & SSH Config

In my case none of the solutions above solved my issue, but ssh-agent does. Basically, I did the following:

  1. Generate key pair using ssh-keygen shown below. It will generate a key pair (in this example .\keyfile and .\keyfile.pub)

    ssh-keygen -t rsa -b 4096 -C "yourname@yourdomain" -f keyfile

  2. Upload keyfile.pub to the git provider

  3. Start ssh-agent on your machine (you can check with ps -ef | grep ssh-agent to see if it is running already)
  4. Run ssh-add .\keyfile to add credentials
  5. Now you can run git clone git@provider:username/project.git

Difference between attr_accessor and attr_accessible

attr_accessor is a Ruby method that gives you setter and getter methods to an instance variable of the same name. So it is equivalent to

class MyModel
  def my_variable
    @my_variable
  end
  def my_variable=(value)
    @my_variable = value
  end
end

attr_accessible is a Rails method that determines what variables can be set in a mass assignment.

When you submit a form, and you have something like MyModel.new params[:my_model] then you want to have a little bit more control, so that people can't submit things that you don't want them to.

You might do attr_accessible :email so that when someone updates their account, they can change their email address. But you wouldn't do attr_accessible :email, :salary because then a person could set their salary through a form submission. In other words, they could hack their way to a raise.

That kind of information needs to be explicitly handled. Just removing it from the form isn't enough. Someone could go in with firebug and add the element into the form to submit a salary field. They could use the built in curl to submit a new salary to the controller update method, they could create a script that submits a post with that information.

So attr_accessor is about creating methods to store variables, and attr_accessible is about the security of mass assignments.

On logout, clear Activity history stack, preventing "back" button from opening logged-in-only Activities

Lots of answers. May be this one will also help-

Intent intent = new Intent(activity, SignInActivity.class)
                .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
                .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
this.startActivity(intent);
this.finish();

Kotlin version-

Intent(this, SignInActivity::class.java).apply {
    addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
    addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
}.also { startActivity(it) }
finish()

./configure : /bin/sh^M : bad interpreter

If you are using TextMate or a similar programme, do save as, and then in encodings choose LF instead of CRLF.

How to create an HTML button that acts like a link?

<form>
    <input type="button" value="Home Page" onclick="window.location.href='http://www.wherever.com'"> 
</form>

Get name of property as a string

I modified your solution to chain over multiple properties:

public static string GetPropertyName<T>(Expression<Func<T>> propertyLambda)
{
    MemberExpression me = propertyLambda.Body as MemberExpression;
    if (me == null)
    {
        throw new ArgumentException("You must pass a lambda of the form: '() => Class.Property' or '() => object.Property'");
    }

    string result = string.Empty;
    do
    {
        result = me.Member.Name + "." + result;
        me = me.Expression as MemberExpression;
    } while (me != null);

    result = result.Remove(result.Length - 1); // remove the trailing "."
    return result;
}

Usage:

string name = GetPropertyName(() => someObject.SomeProperty.SomeOtherProperty);
// returns "SomeProperty.SomeOtherProperty"

UNC path to a folder on my local computer

If you're going to access your local computer (or any computer) using UNC, you'll need to setup a share. If you haven't already setup a share, you could use the default administrative shares. Example:

\\localhost\c$\my_dir

... accesses a folder called "my_dir" via UNC on your C: drive. By default all the hard drives on your machine are shared with hidden shares like c$, d$, etc.

How to BULK INSERT a file into a *temporary* table where the filename is a variable?

You could always construct the #temp table in dynamic SQL. For example, right now I guess you have been trying:

CREATE TABLE #tmp(a INT, b INT, c INT);

DECLARE @sql NVARCHAR(1000);

SET @sql = N'BULK INSERT #tmp ...' + @variables;

EXEC master.sys.sp_executesql @sql;

SELECT * FROM #tmp;

This makes it tougher to maintain (readability) but gets by the scoping issue:

DECLARE @sql NVARCHAR(MAX);

SET @sql = N'CREATE TABLE #tmp(a INT, b INT, c INT);

BULK INSERT #tmp ...' + @variables + ';

SELECT * FROM #tmp;';

EXEC master.sys.sp_executesql @sql;

EDIT 2011-01-12

In light of how my almost 2-year old answer was suddenly deemed incomplete and unacceptable, by someone whose answer was also incomplete, how about:

CREATE TABLE #outer(a INT, b INT, c INT);

DECLARE @sql NVARCHAR(MAX);

SET @sql = N'SET NOCOUNT ON; 

CREATE TABLE #inner(a INT, b INT, c INT);

BULK INSERT #inner ...' + @variables + ';

SELECT * FROM #inner;';

INSERT #outer EXEC master.sys.sp_executesql @sql;

How to use a dot "." to access members of dictionary?

Building on Kugel's answer and taking Mike Graham's words of caution into consideration, what if we make a wrapper?

class DictWrap(object):
  """ Wrap an existing dict, or create a new one, and access with either dot 
    notation or key lookup.

    The attribute _data is reserved and stores the underlying dictionary.
    When using the += operator with create=True, the empty nested dict is 
    replaced with the operand, effectively creating a default dictionary
    of mixed types.

    args:
      d({}): Existing dict to wrap, an empty dict is created by default
      create(True): Create an empty, nested dict instead of raising a KeyError

    example:
      >>>dw = DictWrap({'pp':3})
      >>>dw.a.b += 2
      >>>dw.a.b += 2
      >>>dw.a['c'] += 'Hello'
      >>>dw.a['c'] += ' World'
      >>>dw.a.d
      >>>print dw._data
      {'a': {'c': 'Hello World', 'b': 4, 'd': {}}, 'pp': 3}

  """

  def __init__(self, d=None, create=True):
    if d is None:
      d = {}
    supr = super(DictWrap, self)  
    supr.__setattr__('_data', d)
    supr.__setattr__('__create', create)

  def __getattr__(self, name):
    try:
      value = self._data[name]
    except KeyError:
      if not super(DictWrap, self).__getattribute__('__create'):
        raise
      value = {}
      self._data[name] = value

    if hasattr(value, 'items'):
      create = super(DictWrap, self).__getattribute__('__create')
      return DictWrap(value, create)
    return value

  def __setattr__(self, name, value):
    self._data[name] = value  

  def __getitem__(self, key):
    try:
      value = self._data[key]
    except KeyError:
      if not super(DictWrap, self).__getattribute__('__create'):
        raise
      value = {}
      self._data[key] = value

    if hasattr(value, 'items'):
      create = super(DictWrap, self).__getattribute__('__create')
      return DictWrap(value, create)
    return value

  def __setitem__(self, key, value):
    self._data[key] = value

  def __iadd__(self, other):
    if self._data:
      raise TypeError("A Nested dict will only be replaced if it's empty")
    else:
      return other

Variable not accessible when initialized outside function

To define a global variable which is based off a DOM element a few things must be checked. First, if the code is in the <head> section, then the DOM will not loaded on execution. In this case, an event handler must be placed in order to set the variable after the DOM has been loaded, like this:

var systemStatus;
window.onload = function(){ systemStatus = document.getElementById("system_status"); };

However, if this script is inline in the page as the DOM loads, then it can be done as long as the DOM element in question has loaded above where the script is located. This is because javascript executes synchronously. This would be valid:

<div id="system_status"></div>
<script type="text/javascript">
 var systemStatus = document.getElementById("system_status");
</script>

As a result of the latter example, most pages which run scripts in the body save them until the very end of the document. This will allow the page to load, and then the javascript to execute which in most cases causes a visually faster rendering of the DOM.

Changing Locale within the app itself

In Android M the top solution won't work. I've written a helper class to fix that which you should call from your Application class and all Activities (I would suggest creating a BaseActivity and then make all the Activities inherit from it.

Note: This will also support properly RTL layout direction.

Helper class:

public class LocaleUtils {

    private static Locale sLocale;

    public static void setLocale(Locale locale) {
        sLocale = locale;
        if(sLocale != null) {
            Locale.setDefault(sLocale);
        }
    }

    public static void updateConfig(ContextThemeWrapper wrapper) {
        if(sLocale != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            Configuration configuration = new Configuration();
            configuration.setLocale(sLocale);
            wrapper.applyOverrideConfiguration(configuration);
        }
    }

    public static void updateConfig(Application app, Configuration configuration) {
        if (sLocale != null && Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
            //Wrapping the configuration to avoid Activity endless loop
            Configuration config = new Configuration(configuration);
            // We must use the now-deprecated config.locale and res.updateConfiguration here,
            // because the replacements aren't available till API level 24 and 17 respectively.
            config.locale = sLocale;
            Resources res = app.getBaseContext().getResources();
            res.updateConfiguration(config, res.getDisplayMetrics());
        }
    }
}

Application:

public class App extends Application {
    public void onCreate(){
        super.onCreate();

        LocaleUtils.setLocale(new Locale("iw"));
        LocaleUtils.updateConfig(this, getBaseContext().getResources().getConfiguration());
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        LocaleUtils.updateConfig(this, newConfig);
    }
}

BaseActivity:

public class BaseActivity extends Activity {
    public BaseActivity() {
        LocaleUtils.updateConfig(this);
    }
}

How to access the local Django webserver from outside world

install ngrok in terminal

sudo apt-get install -y ngrok-client

after that run:

ngrok http 8000
or 
ngrok http example.com:9000 

Keeping it simple and how to do multiple CTE in a query

You can have multiple CTEs in one query, as well as reuse a CTE:

WITH    cte1 AS
        (
        SELECT  1 AS id
        ),
        cte2 AS
        (
        SELECT  2 AS id
        )
SELECT  *
FROM    cte1
UNION ALL
SELECT  *
FROM    cte2
UNION ALL
SELECT  *
FROM    cte1

Note, however, that SQL Server may reevaluate the CTE each time it is accessed, so if you are using values like RAND(), NEWID() etc., they may change between the CTE calls.

How to get a variable value if variable name is stored as string?

Had the same issue with arrays, here is how to do it if you're manipulating arrays too :

array_name="ARRAY_NAME"
ARRAY_NAME=("Val0" "Val1" "Val2")

ARRAY=$array_name[@]
echo "ARRAY=${ARRAY}"
ARRAY=("${!ARRAY}")
echo "ARRAY=${ARRAY[@]}"
echo "ARRAY[0]=${ARRAY[0]}"
echo "ARRAY[1]=${ARRAY[1]}"
echo "ARRAY[2]=${ARRAY[2]}"

This will output :

ARRAY=ARRAY_NAME[@]
ARRAY=Val0 Val1 Val2
ARRAY[0]=Val0
ARRAY[1]=Val1
ARRAY[2]=Val2

.htaccess mod_rewrite - how to exclude directory from rewrite rule

add a condition to check for the admin directory, something like:

RewriteCond %{REQUEST_URI} !^/?(admin|user)/
RewriteRule ^([^/] )/([^/] )\.html$ index.php?lang=$1&mod=$2 [L]

RewriteCond %{REQUEST_URI} !^/?(admin|user)/
RewriteRule ^([^/] )/$ index.php?lang=$1&mod=home [L]

Variably modified array at file scope

Imho this is a flaw in many c compilers. I know for a fact that the compilers i worked with do not store a "static const"variable at an adress but replace the use in the code by the very constant. This can be verified as you will get the same checksum for the produced code when you use a preprocessors #define directive and when you use a static const variable.

Either way you should use static const variables instead of #defines whenever possible as the static const is type safe.

SSH Private Key Permissions using Git GUI or ssh-keygen are too open

This is a particularly involved problem on Windows, where it's not enough to just chmod the files correctly. You have to set up your environment.

On Windows, this worked for me:

  1. Install cygwin.

  2. Replace the msysgit ssh.exe with cygwin's ssh.exe.

  3. Using cygwin bash, chmod 600 the private key file, which was "id_rsa" for me.

  4. If it still doesn't work, go to Control Panel -> System Properties -> Advanced -> Environment Variables and add the following environment variable. Then repeat step 3.

    Variable      Value
    CYGWIN      sbmntsec

Change a Git remote HEAD to point to something besides master

There was almost the same question on GitHub a year ago.

The idea was to rename the master branch:

git branch -m master development
git branch -m published master
git push -f origin master 

Making master have what you want people to use, and do all other work in branches.

(a "git-symbolic-ref HEAD refs/head/published" would not be propagated to the remote repo)

This is similar to "How do I delete origin/master in Git".


As said in this thread: (emphasis mine)

"git clone" creates only a single local branch.
To do that, it looks at the HEAD ref of the remote repo, and creates a local branch with the same name as the remote branch referenced by it.

So to wrap that up, you have repo A and clone it:

  • HEAD references refs/heads/master and that exists
    -> you get a local branch called master, starting from origin/master

  • HEAD references refs/heads/anotherBranch and that exists
    -> you get a local branch called anotherBranch, starting from origin/anotherBranch

  • HEAD references refs/heads/master and that doesn't exist
    -> "git clone" complains

Not sure if there's any way to directly modify the HEAD ref in a repo.

(which is the all point of your question, I know ;) )


Maybe the only way would be a "publication for the poor", where you:

 $ git-symbolic-ref HEAD refs/head/published
 $ git-update-server-info
 $ rsync -az .git/* server:/local_path_to/git/myRepo.git/

But that would involve write access to the server, which is not always possible.


As I explain in "Git: Correct way to change Active Branch in a bare repository?", git remote set-head wouldn't change anything on the remote repo.

It would only change the remote tracking branch stored locally in your local repo, in remotes/<name>/HEAD.


With Git 2.29 (Q4 2020), "git remote set-head(man)" that failed still said something that hints the operation went through, which was misleading.

See commit 5a07c6c (17 Sep 2020) by Christian Schlack (cschlack).
(Merged by Junio C Hamano -- gitster -- in commit 39149df, 22 Sep 2020)

remote: don't show success message when set-head fails

Signed-off-by: Christian Schlack

Suppress the message 'origin/HEAD set to master' in case of an error.

$ git remote set-head origin -a
error: Not a valid ref: refs/remotes/origin/master
origin/HEAD set to master

Why did a network-related or instance-specific error occur while establishing a connection to SQL Server?

If your server was working and suddenly started erroring out, your server/instance stopped and connection settings were changed somehow.

For SQL Server 2008 here is how you can fit this:

  1. Goto Start > All Programs > SQL Server 2008 > Configuration Tools > SQL Server Configuration Manager > SQL Server Services.
    And here you'll see all the instances and their state.
  2. The state of the instance you were trying to connect can be stopped here.
  3. Double click on the instance and then click on connect.
  4. It will connect and now go back and run your application, you will be able to connect with no error.

This solution assumes the error is not being caused by something wrong in your connection string.

Convert nested Python dict to object?

x.__dict__.update(d) should do fine.

C# - Winforms - Global Variables

public static class MyGlobals
{
  public static string Global1 = "Hello";
  public static string Global2 = "World";
}

public class Foo
{

    private void Method1()
    {
       string example = MyGlobals.Global1;
       //etc
    }
}

System.Security.SecurityException when writing to Event Log

To give Network Service read permission on the EventLog/Security key (as suggested by Firenzi and royrules22) follow instructions from http://geekswithblogs.net/timh/archive/2005/10/05/56029.aspx

  1. Open the Registry Editor:
    1. Select Start then Run
    2. Enter regedt32 or regedit
  2. Navigate/expand to the following key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security

  3. Right click on this entry and select Permissions

  4. Add the Network Service user

  5. Give it Read permission

UPDATE: The steps above are ok on developer machines, where you do not use deployment process to install application.
However if you deploy your application to other machine(s), consider to register event log sources during installation as suggested in SailAvid's and Nicole Calinoiu's answers.

I am using PowerShell function (calling in Octopus Deploy.ps1)

function Create-EventSources() {
    $eventSources = @("MySource1","MySource2" )
    foreach ($source in $eventSources) {
            if ([System.Diagnostics.EventLog]::SourceExists($source) -eq $false) {
                [System.Diagnostics.EventLog]::CreateEventSource($source, "Application")
            }
    }
}

Classes residing in App_Code is not accessible

make sure that you are using the same namespace as your pages

Accessing SQL Database in Excel-VBA

@firedrawndagger: to list field names/column headers iterate through the recordset Fields collection and insert the name:

Dim myRS as ADODB.Recordset
Dim fld as Field
Dim strFieldName as String 

For Each fld in myRS.Fields
    Activesheet.Selection = fld.Name
    [Some code that moves to next column]
Next

Is it possible to style a select box?

Updated for 2014: You don't need jQuery for this. You can fully style a select box without jQuery using StyleSelect. Eg, given the following select box:

<select class="demo">
  <option value="value1">Label 1</option>
  <option value="value2" selected>Label 2</option>
  <option value="value3">Label 3</option>
</select>

Running styleSelect('select.demo') would create a styled select box as follows:

enter image description here

How do browser cookie domains work?

Although there is the RFC 2965 (Set-Cookie2, had already obsoleted RFC 2109) that should define the cookie nowadays, most browsers don’t fully support that but just comply to the original specification by Netscape.

There is a distinction between the Domain attribute value and the effective domain: the former is taken from the Set-Cookie header field and the latter is the interpretation of that attribute value. According to the RFC 2965, the following should apply:

  • If the Set-Cookie header field does not have a Domain attribute, the effective domain is the domain of the request.
  • If there is a Domain attribute present, its value will be used as effective domain (if the value does not start with a . it will be added by the client).

Having the effective domain it must also domain-match the current requested domain for being set; otherwise the cookie will be revised. The same rule applies for choosing the cookies to be sent in a request.


Mapping this knowledge onto your questions, the following should apply:

  • Cookie with Domain=.example.com will be available for www.example.com
  • Cookie with Domain=.example.com will be available for example.com
  • Cookie with Domain=example.com will be converted to .example.com and thus will also be available for www.example.com
  • Cookie with Domain=example.com will not be available for anotherexample.com
  • www.example.com will be able to set cookie for example.com
  • www.example.com will not be able to set cookie for www2.example.com
  • www.example.com will not be able to set cookie for .com

And to set and read a cookie for/by www.example.com and example.com, set it for .www.example.com and .example.com respectively. But the first (.www.example.com) will only be accessible for other domains below that domain (e.g. foo.www.example.com or bar.www.example.com) where .example.com can also be accessed by any other domain below example.com (e.g. foo.example.com or bar.example.com).

Access restriction on class due to restriction on required library rt.jar?

I met the same problem. I found the answer in the website:http://www.17ext.com.
First,delete the JRE System Libraries. Then,import JRE System Libraries again.

I don't know why.However it fixed my problem,hope it can help you.

Why is it not advisable to have the database and web server on the same machine?

One factor that hasn't been mentioned yet is load balancing. If you start off thinking of the web server and the database as separate machines, you optimize for fewer network round trips and also it gets easier to add a second web server or a second database engine as needs increase.

What is the App_Data folder used for in Visual Studio?

The main intention is for keeping your application's database file(s) in.

And no this will not be accessable from the web by default.

How do I mount a remote Linux folder in Windows through SSH?

I don't think you can mount a Linux folder as a network drive under windows having only access to ssh. I can suggest you to use WinSCP that allows you to transfer file through ssh and it's free.

EDIT: well, sorry. Vinko posted before me and now i've learned a new thing :)

Accessing variables from other functions without using global variables

I don't know specifics of your issue, but if the function needs the value then it can be a parameter passed through the call.

Globals are considered bad because globals state and multiple modifiers can create hard to follow code and strange errors. To many actors fiddling with something can create chaos.

In Subversion can I be a user other than my login name?

I believe if you use the file:// method to access your subversion repository, your changes are always performed under the user which accesses the repository. You need to use a method that supports authentication such as http:// or svn://.

See http://svnbook.red-bean.com/en/1.5/svn-book.html#svn.serverconfig.choosing

jQuery/JavaScript: accessing contents of an iframe

I find this way cleaner:

var $iframe = $("#iframeID").contents();
$iframe.find('selector');

How to connect to local instance of SQL Server 2008 Express

For me it was a windows firewall issue. Allow incoming connections. Opening port didn't work but allow programs did.

Link

Link2

What is the best place for storing uploaded images, SQL database or disk file system?

For auto resizing, try imagemagick... it is used for many major open source content/photo management systems... and I believe that there are some .net extensions for it.

Django Template Variables and Javascript

I use this way in Django 2.1 and work for me and this way is secure (reference):

Django side:

def age(request):
    mydata = {'age':12}
    return render(request, 'test.html', context={"mydata_json": json.dumps(mydata)})

Html side:

<script type='text/javascript'>
     const  mydata = {{ mydata_json|safe }};
console.log(mydata)
 </script>

Scanning Java annotations at runtime

The Classloader API doesn't have an "enumerate" method, because class loading is an "on-demand" activity -- you usually have thousands of classes in your classpath, only a fraction of which will ever be needed (the rt.jar alone is 48MB nowadays!).

So, even if you could enumerate all classes, this would be very time- and memory-consuming.

The simple approach is to list the concerned classes in a setup file (xml or whatever suits your fancy); if you want to do this automatically, restrict yourself to one JAR or one class directory.

HttpContext.Current.Session is null when routing requests

Just add attribute runAllManagedModulesForAllRequests="true" to system.webServer\modules in web.config.

This attribute is enabled by default in MVC and Dynamic Data projects.

What is the C# equivalent of friend?

Take a very common pattern. Class Factory makes Widgets. The Factory class needs to muck about with the internals, because, it is the Factory. Both are implemented in the same file and are, by design and desire and nature, tightly coupled classes -- in fact, Widget is really just an output type from factory.

In C++, make the Factory a friend of Widget class.

In C#, what can we do? The only decent solution that has occurred to me is to invent an interface, IWidget, which only exposes the public methods, and have the Factory return IWidget interfaces.

This involves a fair amount of tedium - exposing all the naturally public properties again in the interface.

WARNING: UNPROTECTED PRIVATE KEY FILE! when trying to SSH into Amazon EC2 Instance

To fix this,

  1. you’ll need to reset the permissions back to default:

    sudo chmod 600 ~/.ssh/id_rsa
    sudo chmod 600 ~/.ssh/id_rsa.pub
    

    If you are getting another error:

    • Are you sure you want to continue connecting (yes/no)? yes
    • Failed to add the host to the list of known hosts (/home/geek/.ssh/known_hosts).
  2. This means that the permissions on that file are also set incorrectly, and can be adjusted with this:

    sudo chmod 644 ~/.ssh/known_hosts
    
  1. Finally, you may need to adjust the directory permissions as well:

    sudo chmod 755 ~/.ssh
    

This should get you back up and running.

Multiple Inheritance in C#

This is along the lines of Lawrence Wenham's answer, but depending on your use case, it may or may not be an improvement -- you don't need the setters.

public interface IPerson {
  int GetAge();
  string GetName();
}

public interface IGetPerson {
  IPerson GetPerson();
}

public static class IGetPersonAdditions {
  public static int GetAgeViaPerson(this IGetPerson getPerson) { // I prefer to have the "ViaPerson" in the name in case the object has another Age property.
    IPerson person = getPerson.GetPersion();
    return person.GetAge();
  }
  public static string GetNameViaPerson(this IGetPerson getPerson) {
    return getPerson.GetPerson().GetName();
  }
}

public class Person: IPerson, IGetPerson {
  private int Age {get;set;}
  private string Name {get;set;}
  public IPerson GetPerson() {
    return this;
  }
  public int GetAge() {  return Age; }
  public string GetName() { return Name; }
}

Now any object that knows how to get a person can implement IGetPerson, and it will automatically have the GetAgeViaPerson() and GetNameViaPerson() methods. From this point, basically all Person code goes into IGetPerson, not into IPerson, other than new ivars, which have to go into both. And in using such code, you don't have to be concerned about whether or not your IGetPerson object is itself actually an IPerson.

Unnamed/anonymous namespaces vs. static functions

I recently began replacing static keywords with anonymous namespaces in my code but immediately ran into a problem where the variables in the namespace were no longer available for inspection in my debugger. I was using VC60, so I don't know if that is a non-issue with other debuggers. My workaround was to define a 'module' namespace, where I gave it the name of my cpp file.

For example, in my XmlUtil.cpp file, I define a namespace XmlUtil_I { ... } for all of my module variables and functions. That way I can apply the XmlUtil_I:: qualification in the debugger to access the variables. In this case, the _I distinguishes it from a public namespace such as XmlUtil that I may want to use elsewhere.

I suppose a potential disadvantage of this approach compared to a truly anonymous one is that someone could violate the desired static scope by using the namespace qualifier in other modules. I don't know if that is a major concern though.

What is a monad?

Monads Are Not Metaphors, but a practically useful abstraction emerging from a common pattern, as Daniel Spiewak explains.

PostgreSQL: Resetting password of PostgreSQL on Ubuntu

Assuming you're the administrator of the machine, Ubuntu has granted you the right to sudo to run any command as any user.
Also assuming you did not restrict the rights in the pg_hba.conf file (in the /etc/postgresql/9.1/main directory), it should contain this line as the first rule:

# Database administrative login by Unix domain socket  
local   all             postgres                                peer

(About the file location: 9.1 is the major postgres version and main the name of your "cluster". It will differ if using a newer version of postgres or non-default names. Use the pg_lsclusters command to obtain this information for your version/system).

Anyway, if the pg_hba.conf file does not have that line, edit the file, add it, and reload the service with sudo service postgresql reload.

Then you should be able to log in with psql as the postgres superuser with this shell command:

sudo -u postgres psql

Once inside psql, issue the SQL command:

ALTER USER postgres PASSWORD 'newpassword';

In this command, postgres is the name of a superuser. If the user whose password is forgotten was ritesh, the command would be:

ALTER USER ritesh PASSWORD 'newpassword';

References: PostgreSQL 9.1.13 Documentation, Chapter 19. Client Authentication

Keep in mind that you need to type postgres with a single S at the end

If leaving the password in clear text in the history of commands or the server log is a problem, psql provides an interactive meta-command to avoid that, as an alternative to ALTER USER ... PASSWORD:

\password username

It asks for the password with a double blind input, then hashes it according to the password_encryption setting and issue the ALTER USER command to the server with the hashed version of the password, instead of the clear text version.

Is it possible to set a number to NaN or infinity?

When using Python 2.4, try

inf = float("9e999")
nan = inf - inf

I am facing the issue when I was porting the simplejson to an embedded device which running the Python 2.4, float("9e999") fixed it. Don't use inf = 9e999, you need convert it from string. -inf gives the -Infinity.

Batch Renaming of Files in a Directory

Be in the directory where you need to perform the renaming.

import os
# get the file name list to nameList
nameList = os.listdir() 
#loop through the name and rename
for fileName in nameList:
    rename=fileName[15:28]
    os.rename(fileName,rename)
#example:
#input fileName bulk like :20180707131932_IMG_4304.JPG
#output renamed bulk like :IMG_4304.JPG

How can I determine the type of an HTML element in JavaScript?

nodeName is the attribute you are looking for. For example:

var elt = document.getElementById('foo');
console.log(elt.nodeName);

Note that nodeName returns the element name capitalized and without the angle brackets, which means that if you want to check if an element is an <div> element you could do it as follows:

elt.nodeName == "DIV"

While this would not give you the expected results:

elt.nodeName == "<div>"

What is Shelving in TFS?

One point that is missed in a lot of these discussions is how you revert back on the SAME machine on which you shelved your changes. Perhaps obvious to most, but wasn't to me. I believe you perform an Undo Pending Changes - is that right?

I understand the process to be as follows:

  1. To shelve your current pending changes, right click the project, Shelve, add a shelve name
  2. This will save (or Shelve) the changes to the server (no-one will see them)
  3. You then do Undo Pending Changes to revert your code back to the last check-in point
  4. You can then do what you need to do with the reverted code baseline
  5. You can Unshelve the changes at any time (may require some merge confliction)

So, if you want to start some work which you may need to Shelve, make sure you check-in before you start, as the check-in point is where you'll return to when doing the Undo Pending Changes step above.

Change link color of the current page with CSS

Use single class name something like class="active" and add it only to current page instead of all pages. If you are at Home something like below:

<ul id="navigation">
<li class="active"><a href="/">Home</a></li>
<li class=""><a href="theatre.php">Theatre</a></li>
<li class=""><a href="programming.php">Programming</a></li> 
</ul>

and your CSS like

li.active{
color: #640200;
}

var self = this?

Just adding to this that in ES6 because of arrow functions you shouldn't need to do this because they capture the this value.

How to get text of an element in Selenium WebDriver, without including child element text?

In the HTML which you have shared:

<div id="a">This is some
   <div id="b">text</div>
</div>

The text This is some is within a text node. To depict the text node in a structured way:

<div id="a">
    This is some
   <div id="b">text</div>
</div>

This Usecase

To extract and print the text This is some from the text node using Selenium's client you have 2 ways as follows:

  • Using splitlines(): You can identify the parent element i.e. <div id="a">, extract the innerHTML and then use splitlines() as follows:

    • using xpath:

      print(driver.find_element_by_xpath("//div[@id='a']").get_attribute("innerHTML").splitlines()[0])
      
    • using xpath:

      print(driver.find_element_by_css_selector("div#a").get_attribute("innerHTML").splitlines()[0])
      
  • Using execute_script(): You can also use the execute_script() method which can synchronously execute JavaScript in the current window/frame as follows:

    • using xpath and firstChild:

      parent_element = driver.find_element_by_xpath("//div[@id='a']")
      print(driver.execute_script('return arguments[0].firstChild.textContent;', parent_element).strip())
      
    • using xpath and childNodes[n]:

      parent_element = driver.find_element_by_xpath("//div[@id='a']")
      print(driver.execute_script('return arguments[0].childNodes[1].textContent;', parent_element).strip())
      

How to use andWhere and orWhere in Doctrine?

Why not just

$q->where("a = 1");
$q->andWhere("b = 1 OR b = 2");
$q->andWhere("c = 1 OR d = 2");

EDIT: You can also use the Expr class (Doctrine2).

Inserting the same value multiple times when formatting a string

You can use advanced string formatting, available in Python 2.6 and Python 3.x:

incoming = 'arbit'
result = '{0} hello world {0} hello world {0}'.format(incoming)

Do I really need to encode '&' as '&amp;'?

Yes. Just as the error said, in HTML, attributes are #PCDATA meaning they're parsed. This means you can use character entities in the attributes. Using & by itself is wrong and if not for lenient browsers and the fact that this is HTML not XHTML, would break the parsing. Just escape it as &amp; and everything would be fine.

HTML5 allows you to leave it unescaped, but only when the data that follows does not look like a valid character reference. However, it's better just to escape all instances of this symbol than worry about which ones should be and which ones don't need to be.

Keep this point in mind; if you're not escaping & to &amp;, it's bad enough for data that you create (where the code could very well be invalid), you might also not be escaping tag delimiters, which is a huge problem for user-submitted data, which could very well lead to HTML and script injection, cookie stealing and other exploits.

Please just escape your code. It will save you a lot of trouble in the future.

How can I dismiss the on screen keyboard?

You can also declare a focusNode for you textfield and when you are done you can just call the unfocus method on that focusNode and also dispose it

class MyHomePage extends StatefulWidget {
  MyHomePageState createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage> {
  TextEditingController _controller = new TextEditingController();

/// declare focus
  final FocusNode _titleFocus = FocusNode();

  @override
  void dispose() {
    _titleFocus.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(),
      floatingActionButton: new FloatingActionButton(
        child: new Icon(Icons.send),
        onPressed: () {
          setState(() {
            // send message
            // dismiss on screen keyboard here

            _titleFocus.unfocus();
            _controller.clear();
          });
        },
      ),
      body: new Container(
        alignment: FractionalOffset.center,
        padding: new EdgeInsets.all(20.0),
        child: new TextFormField(
          controller: _controller,
          focusNode: _titleFocus,
          decoration: new InputDecoration(labelText: 'Example Text'),
        ),
      ),
    );
  }
}

python requests get cookies

Alternatively, you can use requests.Session and observe cookies before and after a request:

>>> import requests
>>> session = requests.Session()
>>> print(session.cookies.get_dict())
{}
>>> response = session.get('http://google.com')
>>> print(session.cookies.get_dict())
{'PREF': 'ID=5514c728c9215a9a:FF=0:TM=1406958091:LM=1406958091:S=KfAG0U9jYhrB0XNf', 'NID': '67=TVMYiq2wLMNvJi5SiaONeIQVNqxSc2RAwVrCnuYgTQYAHIZAGESHHPL0xsyM9EMpluLDQgaj3db_V37NjvshV-eoQdA8u43M8UwHMqZdL-S2gjho8j0-Fe1XuH5wYr9v'}

How to get the CUDA version?

If you run

nvidia-smi

You should find the CUDA Version on the top right corner of the comand's output. At least I found that output for CUDA version 10.0 e.g., enter image description here

__proto__ VS. prototype in JavaScript

Prototype VS. __proto__ VS. [[Prototype]]

When creating a function, a property object called prototype is being created automatically (you didn't create it yourself) and is being attached to the function object (the constructor).
Note: This new prototype object also points to, or has an internal-private link to, the native JavaScript Object.

Example:

function Foo () {
    this.name = 'John Doe';
}

// Foo has an object property called prototype.
// prototype was created automatically when we declared the function Foo.
Foo.hasOwnProperty('prototype'); // true

// Now, we can assign properties and methods to it:
Foo.prototype.myName = function () {
    return 'My name is ' + this.name;
}

If you create a new object out of Foo using the new keyword, you are basically creating (among other things) a new object that has an internal or private link to the function Foo's prototype we discussed earlier:

var b = new Foo();

b.[[Prototype]] === Foo.prototype  // true


The private linkage to that function's object called double brackets prototype or just [[Prototype]]. Many browsers are providing us a public linkage to it that called __proto__!

To be more specific, __proto__ is actually a getter function that belong to the native JavaScript Object. It returns the internal-private prototype linkage of whatever the this binding is (returns the [[Prototype]] of b):

b.__proto__ === Foo.prototype // true

It is worth noting that starting of ECMAScript5, you can also use the getPrototypeOf method to get the internal private linkage:

Object.getPrototypeOf(b) === b.__proto__ // true


NOTE: this answer doesn't intend to cover the whole process of creating new objects or new constructors, but to help better understand what is __proto__, prototype and [[Prototype]] and how it works.

Read url to string in few lines of java code

Java 11+:

URI uri = URI.create("http://www.google.com");
HttpRequest request = HttpRequest.newBuilder(uri).build();
String content = HttpClient.newHttpClient().send(request, BodyHandlers.ofString()).body();

Pass a local file in to URL in Java

Using Java 7:

Paths.get(string).toUri().toURL();

However, you probably want to get a URI. Eg, a URI begins with file:/// but a URL with file:/ (at least, that's what toString produces).

What happens if you don't commit a transaction to a database (say, SQL Server)?

The behaviour is not defined, so you must explicit set a commit or a rollback:

http://docs.oracle.com/cd/B10500_01/java.920/a96654/basic.htm#1003303

"If auto-commit mode is disabled and you close the connection without explicitly committing or rolling back your last changes, then an implicit COMMIT operation is executed."

Hsqldb makes a rollback

con.setAutoCommit(false);
stmt.executeUpdate("insert into USER values ('" +  insertedUserId + "','Anton','Alaf')");
con.close();

result is

2011-11-14 14:20:22,519 main INFO [SqlAutoCommitExample:55] [AutoCommit enabled = false] 2011-11-14 14:20:22,546 main INFO [SqlAutoCommitExample:65] [Found 0# users in database]

React Native: Getting the position of an element

I needed to find the position of an element inside a ListView and used this snippet that works kind of like .offset:

const UIManager = require('NativeModules').UIManager;
const handle = React.findNodeHandle(this.refs.myElement);
UIManager.measureLayoutRelativeToParent(
  handle, 
  (e) => {console.error(e)}, 
  (x, y, w, h) => {
    console.log('offset', x, y, w, h);
  });

This assumes I had a ref='myElement' on my component.

Removing duplicates in the lists

There are also solutions using Pandas and Numpy. They both return numpy array so you have to use the function .tolist() if you want a list.

t=['a','a','b','b','b','c','c','c']
t2= ['c','c','b','b','b','a','a','a']

Pandas solution

Using Pandas function unique():

import pandas as pd
pd.unique(t).tolist()
>>>['a','b','c']
pd.unique(t2).tolist()
>>>['c','b','a']

Numpy solution

Using numpy function unique().

import numpy as np
np.unique(t).tolist()
>>>['a','b','c']
np.unique(t2).tolist()
>>>['a','b','c']

Note that numpy.unique() also sort the values. So the list t2 is returned sorted. If you want to have the order preserved use as in this answer:

_, idx = np.unique(t2, return_index=True)
t2[np.sort(idx)].tolist()
>>>['c','b','a']

The solution is not so elegant compared to the others, however, compared to pandas.unique(), numpy.unique() allows you also to check if nested arrays are unique along one selected axis.

MySQL TEXT vs BLOB vs CLOB

It's worth to mention that CLOB / BLOB data types and their sizes are supported by MySQL 5.0+, so you can choose the proper data type for your need.

http://dev.mysql.com/doc/refman/5.7/en/storage-requirements.html

Data Type   Date Type   Storage Required
(CLOB)      (BLOB)

TINYTEXT    TINYBLOB    L + 1 bytes, where L < 2**8  (255)
TEXT        BLOB        L + 2 bytes, where L < 2**16 (64 K)
MEDIUMTEXT  MEDIUMBLOB  L + 3 bytes, where L < 2**24 (16 MB)
LONGTEXT    LONGBLOB    L + 4 bytes, where L < 2**32 (4 GB)

where L stands for the byte length of a string

Spark: subtract two DataFrames

From spark 3.0

data_cl = reg_data.exceptAll(data_fr)

How to find most common elements of a list?

The simple way of doing this would be (assuming your list is in 'l'):

>>> counter = {}
>>> for i in l: counter[i] = counter.get(i, 0) + 1
>>> sorted([ (freq,word) for word, freq in counter.items() ], reverse=True)[:3]
[(6, 'Jellicle'), (5, 'Cats'), (3, 'to')]

Complete sample:

>>> l = ['Jellicle', 'Cats', 'are', 'black', 'and', 'white,', 'Jellicle', 'Cats', 'are', 'rather', 'small;', 'Jellicle', 'Cats', 'are', 'merry', 'and', 'bright,', 'And', 'pleasant', 'to', 'hear', 'when', 'they', 'caterwaul.', 'Jellicle', 'Cats', 'have', 'cheerful', 'faces,', 'Jellicle', 'Cats', 'have', 'bright', 'black', 'eyes;', 'They', 'like', 'to', 'practise', 'their', 'airs', 'and', 'graces', 'And', 'wait', 'for', 'the', 'Jellicle', 'Moon', 'to', 'rise.', '']
>>> counter = {}
>>> for i in l: counter[i] = counter.get(i, 0) + 1
... 
>>> counter
{'and': 3, '': 1, 'merry': 1, 'rise.': 1, 'small;': 1, 'Moon': 1, 'cheerful': 1, 'bright': 1, 'Cats': 5, 'are': 3, 'have': 2, 'bright,': 1, 'for': 1, 'their': 1, 'rather': 1, 'when': 1, 'to': 3, 'airs': 1, 'black': 2, 'They': 1, 'practise': 1, 'caterwaul.': 1, 'pleasant': 1, 'hear': 1, 'they': 1, 'white,': 1, 'wait': 1, 'And': 2, 'like': 1, 'Jellicle': 6, 'eyes;': 1, 'the': 1, 'faces,': 1, 'graces': 1}
>>> sorted([ (freq,word) for word, freq in counter.items() ], reverse=True)[:3]
[(6, 'Jellicle'), (5, 'Cats'), (3, 'to')]

With simple I mean working in nearly every version of python.

if you don't understand some of the functions used in this sample, you can always do this in the interpreter (after pasting the code above):

>>> help(counter.get)
>>> help(sorted)

How can I center a div within another div?

I would try defining a more specific width, for starters. It's hard to center something that already spans the entire width:

#container {
    width: 400px;
}

How to open the terminal in Atom?

For Windows follow the below steps

(1)go to file>setting and click on install enter image description here

(2) then type "platformio-ide-terminal" in packages and hit install enter image description here (3) after finish install restart atom and press

 ctrl + ~ for opening the terminal `~` is the key below `Esc`

enter image description here

welcome ;-)

How to convert HTML to PDF using iText

You can do it with the HTMLWorker class (deprecated) like this:

import com.itextpdf.text.html.simpleparser.HTMLWorker;
//...
try {
    String k = "<html><body> This is my Project </body></html>";
    OutputStream file = new FileOutputStream(new File("C:\\Test.pdf"));
    Document document = new Document();
    PdfWriter.getInstance(document, file);
    document.open();
    HTMLWorker htmlWorker = new HTMLWorker(document);
    htmlWorker.parse(new StringReader(k));
    document.close();
    file.close();
} catch (Exception e) {
    e.printStackTrace();
}

or using the XMLWorker, (download from this jar) using this code:

import com.itextpdf.tool.xml.XMLWorkerHelper;
//...
try {
    String k = "<html><body> This is my Project </body></html>";
    OutputStream file = new FileOutputStream(new File("C:\\Test.pdf"));
    Document document = new Document();
    PdfWriter writer = PdfWriter.getInstance(document, file);
    document.open();
    InputStream is = new ByteArrayInputStream(k.getBytes());
    XMLWorkerHelper.getInstance().parseXHtml(writer, document, is);
    document.close();
    file.close();
} catch (Exception e) {
    e.printStackTrace();
}

Requery a subform from another form?

Just discovered that if the source table for a subform is updated using adodb, it takes a while until the requery can find the updated information.

In my case, I was adding some records with 'dbconn.execute "sql" ' and wondered why the requery command in vba doesn't seem to work. When I was debugging, the requery worked. Added a 2-3 second wait in the code before requery just to test made a difference.

But changing to 'currentdb.execute "sql" ' fixed the problem immediately.

Displaying output of a remote command with Ansible

Prints pubkey and avoid the changed status by adding changed_when: False to cat task:

- name: Generate SSH keys for vagrant user   
  user: name=vagrant generate_ssh_key=yes ssh_key_bits=2048

- name: Check SSH public key   
  command: /bin/cat $home_directory/.ssh/id_rsa.pub
  register: cat
  changed_when: False

- name: Print SSH public key
  debug: var=cat.stdout

- name: Wait for user to copy SSH public key   
  pause: prompt="Please add the SSH public key above to your GitHub account"

Display TIFF image in all web browser

I found this resource that details the various methods: How to embed TIFF files in HTML documents

As mentioned, it will very much depend on browser support for the format. Viewing that page in Chrome on Windows didn't display any of the images.

It would also be helpful if you posted the code you've tried already.

How to get First and Last record from a sql query?

In some cases - when not so many columns - useful the WINDOW functions FIRST_VALUE() and LAST_VALUE().

 SELECT
    FIRST_VALUE(timestamp) over (ORDER BY timestamp ASC) as created_dt,
    LAST_VALUE(timestamp) over (ORDER BY timestamp ASC) as last_update_dt,
    LAST_VALUE(action) over (ORDER BY timestamp ASC) as last_action
FROM events

This query sort data only once.

It can be used for getting fisrt and last rows by some ID

SELECT DISTINCT
    order_id,
    FIRST_VALUE(timestamp) over (PARTITION BY order_id ORDER BY timestamp ASC) as created_dt,
    LAST_VALUE(timestamp) over (PARTITION BY order_id ORDER BY timestamp ASC) as last_update_dt,
    LAST_VALUE(action) over (PARTITION BY order_id ORDER BY timestamp ASC) as last_action

FROM events as x

Is it possible to animate scrollTop with jQuery?

If you want to move down at the end of the page (so you don't need to scroll down to bottom) , you can use:

$('body').animate({ scrollTop: $(document).height() });

AngularJS accessing DOM elements inside directive template

I don't think there is a more "angular way" to select an element. See, for instance, the way they are achieving this goal in the last example of this old documentation page:

{
     template: '<div>' +
    '<div class="title">{{title}}</div>' +
    '<div class="body" ng-transclude></div>' +
    '</div>',

    link: function(scope, element, attrs) {
        // Title element
        var title = angular.element(element.children()[0]),
        // ...
    }
}

Ansible playbook shell output

If you need a specific exit status, Ansible provides a way to do that via callback plugins.

Example. It's a very good option if you need a 100% accurate exit status.

If not, you can always use the Debug Module, which is the standard for this cases of use.

Cheers

Regular Expressions- Match Anything

  1. Regex:

    /I bought.*sheep./
    

    Matches - the whole string till the end of line

    I bought sheep. I bought a sheep. I bought five sheep.

  2. Regex:

    /I bought(.*)sheep./
    

    Matches - the whole string and also capture the sub string within () for further use

    I bought sheep. I bought a sheep. I bought five sheep.

    I boughtsheep. I bought a sheep. I bought fivesheep.

    Example using Javascript/Regex

    'I bought sheep. I bought a sheep. I bought five sheep.'.match(/I bought(.*)sheep./)[0];
    

    Output:

    "I bought sheep. I bought a sheep. I bought five sheep."

    'I bought sheep. I bought a sheep. I bought five sheep.'.match(/I bought(.*)sheep./)[1];
    

    Output:

    " sheep. I bought a sheep. I bought five "

How to remove title bar from the android activity?

You can try:

<activity android:name=".YourActivityName"
          android:theme="@style/Theme.Design.NoActionBar">

that works for me

Get 2 Digit Number For The Month

For me the quickest solution was

DATE_FORMAT(CURDATE(),'%m')

delete image from folder PHP

First Check that is image exists? if yes then simply Call unlink(your file path) function to remove you file otherwise show message to the user.

              if (file_exists($filePath)) 
               {
                 unlink($filePath);
                  echo "File Successfully Delete."; 
              }
              else
              {
               echo "File does not exists"; 
              }

Django - filtering on foreign key properties

student_user = User.objects.get(id=user_id)
available_subjects = Subject.objects.exclude(subject_grade__student__user=student_user) # My ans
enrolled_subjects = SubjectGrade.objects.filter(student__user=student_user)
context.update({'available_subjects': available_subjects, 'student_user': student_user, 
                'request':request, 'enrolled_subjects': enrolled_subjects})

In my application above, i assume that once a student is enrolled, a subject SubjectGrade instance will be created that contains the subject enrolled and the student himself/herself.

Subject and Student User model is a Foreign Key to the SubjectGrade Model.

In "available_subjects", i excluded all the subjects that are already enrolled by the current student_user by checking all subjectgrade instance that has "student" attribute as the current student_user

PS. Apologies in Advance if you can't still understand because of my explanation. This is the best explanation i Can Provide. Thank you so much

Jupyter Notebook not saving: '_xsrf' argument missing from post

I also came across the same error. I just opened another non-running Juputer notebook and an error is automatically gone.

Exclude all transitive dependencies of a single dependency

I use the following workaround : instead of trying to exclude the artifact in all appropriate dependencies, I draw the dependency as "provided" at top level. For example, to avoid shipping xml-apis "whatever version" :

    <dependency>
        <groupId>xml-apis</groupId>
        <artifactId>xml-apis</artifactId>
        <version>[1.0,]</version>
        <scope>provided</scope>
    </dependency>

How do I log errors and warnings into a file?

Simply put these codes at top of your PHP/index file:

error_reporting(E_ALL); // Error/Exception engine, always use E_ALL

ini_set('ignore_repeated_errors', TRUE); // always use TRUE

ini_set('display_errors', FALSE); // Error/Exception display, use FALSE only in production environment or real server. Use TRUE in development environment

ini_set('log_errors', TRUE); // Error/Exception file logging engine.
ini_set('error_log', 'your/path/to/errors.log'); // Logging file path

Delete all rows in a table based on another table

To Delete table records based on another table

     Delete From Table1 a,Table2 b where a.id=b.id

    Or

      DELETE FROM Table1
    WHERE Table1.id IN (SELECT Table2.id FROM Table2)

  Or

        DELETE Table1
     FROM Table1 t1 INNER JOIN Table2 t2 ON t1.ID = t2.ID;

PIG how to count a number of rows in alias

COUNT is part of pig see the manual

LOGS= LOAD 'log';
LOGS_GROUP= GROUP LOGS ALL;
LOG_COUNT = FOREACH LOGS_GROUP GENERATE COUNT(LOGS);

How to use hex() without 0x in Python?

>>> format(3735928559, 'x')
'deadbeef'

Multiple models in a view

  1. Create one new class in your model and properties of LoginViewModel and RegisterViewModel:

    public class UserDefinedModel() 
    {
        property a1 as LoginViewModel 
        property a2 as RegisterViewModel 
    }
    
  2. Then use UserDefinedModel in your view.

How to add the text "ON" and "OFF" to toggle button

_x000D_
_x000D_
.switch {_x000D_
  position: relative;_x000D_
  display: inline-block;_x000D_
  width: 90px;_x000D_
  height: 34px;_x000D_
}_x000D_
_x000D_
.switch input {display:none;}_x000D_
_x000D_
.slider {_x000D_
  position: absolute;_x000D_
  cursor: pointer;_x000D_
  top: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  bottom: 0;_x000D_
  background-color: #ca2222;_x000D_
  -webkit-transition: .4s;_x000D_
  transition: .4s;_x000D_
}_x000D_
_x000D_
.slider:before {_x000D_
  position: absolute;_x000D_
  content: "";_x000D_
  height: 26px;_x000D_
  width: 26px;_x000D_
  left: 4px;_x000D_
  bottom: 4px;_x000D_
  background-color: white;_x000D_
  -webkit-transition: .4s;_x000D_
  transition: .4s;_x000D_
}_x000D_
_x000D_
input:checked + .slider {_x000D_
  background-color: #2ab934;_x000D_
}_x000D_
_x000D_
input:focus + .slider {_x000D_
  box-shadow: 0 0 1px #2196F3;_x000D_
}_x000D_
_x000D_
input:checked + .slider:before {_x000D_
  -webkit-transform: translateX(55px);_x000D_
  -ms-transform: translateX(55px);_x000D_
  transform: translateX(55px);_x000D_
}_x000D_
_x000D_
/*------ ADDED CSS ---------*/_x000D_
.on_x000D_
{_x000D_
  display: none;_x000D_
}_x000D_
_x000D_
.on, .off_x000D_
{_x000D_
  color: white;_x000D_
  position: absolute;_x000D_
  transform: translate(-50%,-50%);_x000D_
  top: 50%;_x000D_
  left: 50%;_x000D_
  font-size: 10px;_x000D_
  font-family: Verdana, sans-serif;_x000D_
}_x000D_
_x000D_
input:checked+ .slider .on_x000D_
{display: block;}_x000D_
_x000D_
input:checked + .slider .off_x000D_
{display: none;}_x000D_
_x000D_
/*--------- END --------*/_x000D_
_x000D_
/* Rounded sliders */_x000D_
.slider.round {_x000D_
  border-radius: 34px;_x000D_
}_x000D_
_x000D_
.slider.round:before {_x000D_
  border-radius: 50%;}
_x000D_
<label class="switch"><input type="checkbox" id="togBtn"><div class="slider round"><!--ADDED HTML --><span class="on">Confirmed</span><span class="off">NA</span><!--END--></div></label>
_x000D_
_x000D_
_x000D_

Objective-C: Reading a file line by line

This answer is NOT ObjC but C.

Since ObjC is 'C' based, why not use fgets?

And yes, I'm sure ObjC has it's own method - I'm just not proficient enough yet to know what it is :)

How to enable support of CPU virtualization on Macbook Pro?

CPU Virtualization is enabled by default on all MacBooks with compatible CPUs (i7 is compatible). You can try to reset PRAM if you think it was disabled somehow, but I doubt it.

I think the issue might be in the old version of OS. If your MacBook is i7, then you better upgrade OS to something newer.

Compare 2 JSON objects

Simply parsing the JSON and comparing the two objects is not enough because it wouldn't be the exact same object references (but might be the same values).

You need to do a deep equals.

From http://threebit.net/mail-archive/rails-spinoffs/msg06156.html - which seems the use jQuery.

Object.extend(Object, {
   deepEquals: function(o1, o2) {
     var k1 = Object.keys(o1).sort();
     var k2 = Object.keys(o2).sort();
     if (k1.length != k2.length) return false;
     return k1.zip(k2, function(keyPair) {
       if(typeof o1[keyPair[0]] == typeof o2[keyPair[1]] == "object"){
         return deepEquals(o1[keyPair[0]], o2[keyPair[1]])
       } else {
         return o1[keyPair[0]] == o2[keyPair[1]];
       }
     }).all();
   }
});

Usage:

var anObj = JSON.parse(jsonString1);
var anotherObj= JSON.parse(jsonString2);

if (Object.deepEquals(anObj, anotherObj))
   ...

Pass element ID to Javascript function

Check this: http://jsfiddle.net/h7kRt/1/,

you should change in jsfiddle on top-left to No-wrap in <head>

Your code looks good and it will work inside a normal page. In jsfiddle your function was being defined inside a load handler and thus is in a different scope. By changing to No-wrap you have it in the global scope and can use it as you wanted.

WPF TemplateBinding vs RelativeSource TemplatedParent

TemplateBinding - More limiting than using regular Binding

  • More efficient than a Binding but it has less functionality
  • Only works inside a ControlTemplate's visual tree
  • Doesn't work with properties on Freezables
  • Doesn't work within a ControlTemplate's Trigger
  • Provides a shortcut in setting properties(not as verbose),e.g. {TemplateBinding targetProperty}

Regular Binding - Does not have above limitations of TemplateBinding

  • Respects Parent Properties
  • Resets Target Values to clear out any explicitly set values
  • Example: <Ellipse Fill="{Binding RelativeSource={RelativeSource TemplatedParent},Path=Background}"/>

Remove Datepicker Function dynamically

This is the solution I use. It has more lines but it will only create the datepicker once.

$('#txtSearch').datepicker({
    constrainInput:false,
    beforeShow: function(){
        var t = $('#ddlSearchType').val();
        if( ['Required Date', 'Submitted Date'].indexOf(t) ) {
            $('#txtSearch').prop('readonly', false);
            return false;
        }
        else $('#txtSearch').prop('readonly', true);
    }
});

The datepicker will not show unless the value of ddlSearchType is either "Required Date" or "Submitted Date"

Converting xml to string using C#

As Chris suggests, you can do it like this:

public string GetXMLAsString(XmlDocument myxml)
{
    return myxml.OuterXml;
}

Or like this:

public string GetXMLAsString(XmlDocument myxml)
    {

        StringWriter sw = new StringWriter();
        XmlTextWriter tx = new XmlTextWriter(sw);
        myxml.WriteTo(tx);

        string str = sw.ToString();// 
        return str;
    }

and if you really want to create a new XmlDocument then do this

XmlDocument newxmlDoc= myxml

"Faceted Project Problem (Java Version Mismatch)" error message

Did you check your Project Properties -> Project Facets panel? (From that post)

A WTP project is composed of multiple units of functionality (known as facets).

The Java facet version needs to always match the java compiler compliance level.
The best way to change java level is to use the Project Facets properties panel as that will update both places at the same time.

WTP

The "Project->Preferences->Project Facets" stores its configuration in this file, "org.eclipse.wst.common.project.facet.core.xml", under the ".settings" directory.

The content might look like this

<?xml version="1.0" encoding="UTF-8"?>
<faceted-project>
  <runtime name="WebSphere Application Server v6.1"/>
  <fixed facet="jst.java"/>
  <fixed facet="jst.web"/>
  <installed facet="jst.java" version="5.0"/>
  <installed facet="jst.web" version="2.4"/>
  <installed facet="jsf.ibm" version="7.0"/>
  <installed facet="jsf.base" version="7.0"/>
  <installed facet="web.jstl" version="1.1"/>
</faceted-project>

Check also your Java compliance level:

Java compliance level

JSON.NET Error Self referencing loop detected for type

My Problem Solved With Custom Config JsonSerializerSettings:

services.AddMvc(
  // ...
               ).AddJsonOptions(opt =>
                 {
                opt.SerializerSettings.ReferenceLoopHandling =
                    Newtonsoft.Json.ReferenceLoopHandling.Serialize;
                opt.SerializerSettings.PreserveReferencesHandling =
                    Newtonsoft.Json.PreserveReferencesHandling.Objects;
                 });

How to change environment's font size?

There is a setting window.zoom that can enlarge the entire window content including the top menus and side nav tree. Setting this to 1 on a 4k monitor makes the content similar to a 1080p monitor of the same physical size.

What is the difference between application server and web server?

As many have said before, web servers handle HTTP petitions, while application servers handle petitions for distributed components. So, maybe the easiest way to understand the difference is to compare the two products in regards to programming environment they offer.

Web Server -> Programming Environment

IIS : ASP (.NET)

Tomcat : Servlet

Jetty : Servlet

Apache : Php, CGI

Application Servers -> Programming Environment

MTS : COM+

WAS : EJB

JBoss : EJB

WebLogic Application Server : EJB

The crucial difference is that application servers support some distributed component technology, providing features like remote invocation and distributed transactions, like EJB in Java world or COM+ on Microsoft platform. Http server often support some more simple programming environments, often scripting, like ASP (.NET) in case of Microsoft or Servlet--based, including JSP and many other in case of Java or PHP and CGI in case of Apache.

Other capabilities like load-balancing, clustering, session-failover, connection pooling etc. that used to be in the realm of application servers, are becoming available on web servers as well directly or through some third party products.

Finally, it is worth noting that the picture is further distorted with "lightweight containers" like Spring Framework, that often supplement the purpose of application servers in more simple manner and without the application server infrastructure. And since distribution aspect in applications is moving from distributed component towards service paradigm and SOA architecture, there is less and less space left for traditional application servers.

Node Sass couldn't find a binding for your current environment

node-sass node module uses darwin binary file which is dependent on the version of node. This issue occurs when the binary file is not downloaded or wrong binary file is downloaded.

Node sass error

Reinstall node modules will download expected binary of node-sass:-

For Mac users:

rm -rf node_modules
npm cache clean --force
npm i
npm rebuild node-sass --force

For Windows users:

rmdir node_modules
npm cache clean --force
npm i
npm rebuild node-sass --force

but for some users, you need to check your node version's compatibility with node-sass version. Make it compatible using below table and run above commands again to fix this issue.

Node JS compatible node-sass version

If issue is still not fixed, check node-sass supported environment's list:- https://github.com/sass/node-sass/releases/

How to use BigInteger?

Since you are summing up some int values together, there is no need to use BigInteger. long is enough for that. int is 32 bits, while long is 64 bits, that can contain the sum of all int values.

nodemon command is not recognized in terminal for node js server

For me setting the path variables was enough for the solution:

Step 1) Install nodemon globally using npm install -g nodemon

enter image description here

Step 2) Set the ENVIRONMENT VARIABLES, by adding npm path the PATH variable

1) Open Control Panel, search for environment variable

enter image description here

2) Click open the environment variable enter image description here

3) Create new variable NPM set it with the path of npm as appears from the nodemon installation cmd output (as seen from nodemon installation screenshot):

enter image description here

4) Now add NPM variable to the PATH variables:

enter image description here

Step 3) Close the 'cmd' and open a fresh one and type nodemon --version enter image description here

Now we have the nodemon ready to use :)

How to create materialized views in SQL Server?

They're called indexed views in SQL Server - read these white papers for more background:

Basically, all you need to do is:

  • create a regular view
  • create a clustered index on that view

and you're done!

The tricky part is: the view has to satisfy quite a number of constraints and limitations - those are outlined in the white paper. If you do this, that's all there is. The view is being updated automatically, no maintenance needed.

Additional resources:

How to find the date of a day of the week from a date using PHP?

I had to use a similar solution for Portuguese (Brazil):

<?php
$scheduled_day = '2018-07-28';
$days = ['Dom','Seg','Ter','Qua','Qui','Sex','Sáb'];
$day = date('w',strtotime($scheduled_day));
$scheduled_day = date('d-m-Y', strtotime($scheduled_day))." ($days[$day])";
// provides 28-07-2018 (Sáb)

Play audio from a stream using C#

NAudio wraps the WaveOutXXXX API. I haven't looked at the source, but if NAudio exposes the waveOutWrite() function in a way that doesn't automatically stop playback on each call, then you should be able to do what you really want, which is to start playing the audio stream before you've received all the data.

Using the waveOutWrite() function allows you to "read ahead" and dump smaller chunks of audio into the output queue - Windows will automatically play the chunks seamlessly. Your code would have to take the compressed audio stream and convert it to small chunks of WAV audio on the fly; this part would be really difficult - all the libraries and components I've ever seen do MP3-to-WAV conversion an entire file at a time. Probably your only realistic chance is to do this using WMA instead of MP3, because you can write simple C# wrappers around the multimedia SDK.

Pandas/Python: Set value of one column based on value in another column

You can use np.where() to set values based on a specified condition:

#df
   c1  c2  c3
0   4   2   1
1   8   7   9
2   1   5   8
3   3   3   5
4   3   6   8

Now change values (or set) in column ['c2'] based on your condition.

df['c2'] = np.where(df.c1 == 8,'X', df.c3)

   c1  c3  c4
0   4   1   1
1   8   9   X
2   1   8   8
3   3   5   5
4   3   8   8

Remove warning messages in PHP

You could suppress the warning using error_reporting but the much better way is to fix your script in the first place.

If you don't know how, edit your question and show us the line in question and the warning that is displayed.

vagrant primary box defined but commands still run against all boxes

The primary flag seems to only work for vagrant ssh for me.

In the past I have used the following method to hack around the issue.

# stage box intended for configuration closely matching production if ARGV[1] == 'stage'     config.vm.define "stage" do |stage|         box_setup stage, \         "10.9.8.31", "deploy/playbook_full_stack.yml", "deploy/hosts/vagrant_stage.yml"     end end 

How to set background color in jquery

You actually got it. Just forgot some quotes.

$(this).css({backgroundColor: 'red'});

or

$(this).css('background-color', 'red');

You don't need to pass over a map/object to set only one property. You can just put pass it as string. Note that if passing an object you cannot use a -. All CSS properties which have such a character are mapped with capital letters.

Reference: .css()

AngularJS directive does not update on scope variable changes

We can try this

$scope.$apply(function() {
    $scope.step1 = true;
    //scope.list2.length = 0;
});

http://jsfiddle.net/Etb9d/

How to create a horizontal loading progress bar?

Just add a STYLE line and your progress becomes horizontal:

<ProgressBar
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/progress"
        android:layout_centerHorizontal="true"      
        android:layout_centerVertical="true"      
        android:max="100" 
        android:progress="45"/>

Getting current device language in iOS?

This will probably give you what you want:

NSLocale *locale = [NSLocale currentLocale];

NSString *language = [locale displayNameForKey:NSLocaleIdentifier 
                                         value:[locale localeIdentifier]];

It will show the name of the language, in the language itself. For example:

Français (France)
English (United States)

Bad Request - Invalid Hostname IIS7

I'm not sure if this was your problem but for anyone that's trying to access his web application from his machine and having this problem:

Make sure you're connecting to 127.0.0.1 (a.k.a localhost) and not to your external IP address.

Your URL should be something like http://localhost:8181/ or http://127.0.0.1:8181 and not http://YourExternalIPaddress:8181/.


Additional information:
The reason this works is because your firewall may block your own request. It can be a firewall on your OS and it can be (the usual) your router.

When you connect to your external IP address, you connect to you from the internet, as if you were a stranger (or a hacker).
However when you connect to your localhost, you connect locally as yourself and the block is obviously not needed (& avoided altogether).

C++ Matrix Class

C++ is mostly a superset of C. You can continue doing what you were doing.

That said, in C++, what you ought to do is to define a proper Matrix class that manages its own memory. It could, for example be backed by an internal std::vector, and you could override operator[] or operator() to index into the vector appropriately (for example, see: How do I create a subscript operator for a Matrix class? from the C++ FAQ).

To get you started:

class Matrix
{
public:
    Matrix(size_t rows, size_t cols);
    double& operator()(size_t i, size_t j);
    double operator()(size_t i, size_t j) const;

private:
    size_t mRows;
    size_t mCols;
    std::vector<double> mData;
};

Matrix::Matrix(size_t rows, size_t cols)
: mRows(rows),
  mCols(cols),
  mData(rows * cols)
{
}

double& Matrix::operator()(size_t i, size_t j)
{
    return mData[i * mCols + j];
}

double Matrix::operator()(size_t i, size_t j) const
{
    return mData[i * mCols + j];
}

(Note that the above doesn't do any bounds-checking, and I leave it as an exercise to template it so that it works for things other than double.)

Combine GET and POST request methods in Spring

Below is one of the way by which you can achieve that, may not be an ideal way to do.

Have one method accepting both types of request, then check what type of request you received, is it of type "GET" or "POST", once you come to know that, do respective actions and the call one method which does common task for both request Methods ie GET and POST.

@RequestMapping(value = "/books")
public ModelAndView listBooks(HttpServletRequest request){
     //handle both get and post request here
     // first check request type and do respective actions needed for get and post.

    if(GET REQUEST){

     //WORK RELATED TO GET

    }else if(POST REQUEST){

      //WORK RELATED TO POST

    }

    commonMethod(param1, param2....);
}

How to justify navbar-nav in Bootstrap 3

I know this is an old post but I would like share my solution. I spent several hours trying to make a justified navigation menu. You do not really need to modify anything in bootstrap css. Just need to add the correct class in the html.

   <nav class="nav navbar-default navbar-fixed-top">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#collapsable-1" aria-expanded="false">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="#top">Brand Name</a>
        </div>
        <div class="collapse navbar-collapse" id="collapsable-1">
            <ul class="nav nav-justified">
                <li><a href="#about-me">About Me</a></li>
                <li><a href="#skills">Skills</a></li>
                <li><a href="#projects">Projects</a></li>
                <li><a href="#contact-me">Contact Me</a></li>
            </ul>
        </div>
    </nav>

This CSS code will simply remove the navbar-brand class when the screen reaches 768px.

media@(min-width: 768px){
   .navbar-brand{
        display: none;
    }
}

How to convert a string from uppercase to lowercase in Bash?

If you define your variable using declare (old: typeset) then you can state the case of the value throughout the variable's use.

$ declare -u FOO=AbCxxx
$ echo $FOO
ABCXXX

"-l" does lc.

Iterating through a List Object in JSP

you can read empList directly in forEach tag.Try this

 <table>
       <c:forEach items="${sessionScope.empList}" var="employee">
            <tr>
                <td>Employee ID: <c:out value="${employee.eid}"/></td>
                <td>Employee Pass: <c:out value="${employee.ename}"/></td>  
            </tr>
        </c:forEach>
    </table>

Javascript use variable as object name

You can't do this in general, except at the window scope, where you can write window[objname].value = 'value';

mysql_config not found when installing mysqldb python interface

The package libmysqlclient-dev is deprecated, so use the below command to fix it.

Package libmysqlclient-dev is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source

sudo apt-get install default-libmysqlclient-dev

How do I assign a null value to a variable in PowerShell?

These are automatic variables, like $null, $true, $false etc.

about_Automatic_Variables, see https://technet.microsoft.com/en-us/library/hh847768.aspx?f=255&MSPPError=-2147217396

$NULL
$null is an automatic variable that contains a NULL or empty value. You can use this variable to represent an absent or undefined value in commands and scripts.

Windows PowerShell treats $null as an object with a value, that is, as an explicit placeholder, so you can use $null to represent an empty value in a series of values.

For example, when $null is included in a collection, it is counted as one of the objects.

C:\PS> $a = ".dir", $null, ".pdf"
C:\PS> $a.count
3

If you pipe the $null variable to the ForEach-Object cmdlet, it generates a value for $null, just as it does for the other objects.

PS C:\ps-test> ".dir", $null, ".pdf" | Foreach {"Hello"}
Hello
Hello
Hello

As a result, you cannot use $null to mean "no parameter value." A parameter value of $null overrides the default parameter value.

However, because Windows PowerShell treats the $null variable as a placeholder, you can use it scripts like the following one, which would not work if $null were ignored.

$calendar = @($null, $null, “Meeting”, $null, $null, “Team Lunch”, $null)
$days = Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"
$currentDay = 0

foreach($day in $calendar)
{
    if($day –ne $null)
    {
        "Appointment on $($days[$currentDay]): $day"
    }

    $currentDay++
}

output:

Appointment on Tuesday: Meeting
Appointment on Friday: Team lunch

PHP array: count or sizeof?

I know this is old but just wanted to mention that I tried this with PHP 7.2:

<?php
//Creating array with 1 000 000 elements
$a = array();
for ($i = 0; $i < 1000000; ++$i)
{
    $a[] = 100;
}

//Measure
$time = time();
for ($i = 0; $i < 1000000000; ++$i)
{
    $b = count($a);
}
print("1 000 000 000 iteration of count() took ".(time()-$time)." sec\n");

$time = time();
for ($i = 0; $i < 1000000000; ++$i)
{
    $b = sizeof($a);
}
print("1 000 000 000 iteration of sizeof() took ".(time()-$time)." sec\n");
?>

and the result was:

1 000 000 000 iteration of count() took 414 sec
1 000 000 000 iteration of sizeof() took 1369 sec

So just use count().

libclntsh.so.11.1: cannot open shared object file.

probably you need to sudo into an account registered with relevant env settings :)

How do I setup the dotenv file in Node.js?

In my case, I was creating a vscode extension in which __dirname was referring to something like d:\extension\my_extension\out.

the root folder was my_extension, but __dirname was pointing to my_extension\out

so I fixed it by writing

require('dotenv').config({path: __dirname.slice(0,-3)+'/.env'});

How are zlib, gzip and zip related? What do they have in common and how are they different?

ZIP is a file format used for storing an arbitrary number of files and folders together with lossless compression. It makes no strict assumptions about the compression methods used, but is most frequently used with DEFLATE.

Gzip is both a compression algorithm based on DEFLATE but less encumbered with potential patents et al, and a file format for storing a single compressed file. It supports compressing an arbitrary number of files and folders when combined with tar. The resulting file has an extension of .tgz or .tar.gz and is commonly called a tarball.

zlib is a library of functions encapsulating DEFLATE in its most common LZ77 incarnation.

How to call a function after a div is ready?

To do something after certain div load from function .load(). I think this exactly what you need:

  $('#divIDer').load(document.URL +  ' #divIDer',function() {

       // call here what you want .....


       //example
       $('#mydata').show();
  });

How to convert Java String into byte[]?

Try using String.getBytes(). It returns a byte[] representing string data. Example:

String data = "sample data";
byte[] byteData = data.getBytes();

Adding author name in Eclipse automatically to existing files

Shift + Alt + J will help you add author name in existing file.

To add author name automatically,
go to Preferences --> --> Code Style --> Code Templates

Preferences -- Java -- Code Style -- Code Templates

in case you don't find above option in new versions of Eclipse - install it from https://marketplace.eclipse.org/content/jautodoc

Sheet.getRange(1,1,1,12) what does the numbers in bracket specify?

Found these docu on the google docu pages:

  • row --- int --- top row of the range
  • column --- int--- leftmost column of the range
  • optNumRows --- int --- number of rows in the range.
  • optNumColumns --- int --- number of columns in the range

In your example, you would get (if you picked the 3rd row) "C3:O3", cause C --> O is 12 columns

edit

Using the example on the docu:

// The code below will get the number of columns for the range C2:G8
// in the active spreadsheet, which happens to be "4"
var count = SpreadsheetApp.getActiveSheet().getRange(2, 3, 6, 4).getNumColumns(); Browser.msgBox(count);

The values between brackets:
2: the starting row = 2
3: the starting col = C
6: the number of rows = 6 so from 2 to 8
4: the number of cols = 4 so from C to G

So you come to the range: C2:G8

C# string does not contain possible?

So you can utilize short-circuiting:

bool containsBoth = compareString.Contains(firstString) && 
                    compareString.Contains(secondString);

Using Java with Nvidia GPUs (CUDA)

First of all, you should be aware of the fact that CUDA will not automagically make computations faster. On the one hand, because GPU programming is an art, and it can be very, very challenging to get it right. On the other hand, because GPUs are well-suited only for certain kinds of computations.

This may sound confusing, because you can basically compute anything on the GPU. The key point is, of course, whether you will achieve a good speedup or not. The most important classification here is whether a problem is task parallel or data parallel. The first one refers, roughly speaking, to problems where several threads are working on their own tasks, more or less independently. The second one refers to problems where many threads are all doing the same - but on different parts of the data.

The latter is the kind of problem that GPUs are good at: They have many cores, and all the cores do the same, but operate on different parts of the input data.

You mentioned that you have "simple math but with huge amount of data". Although this may sound like a perfectly data-parallel problem and thus like it was well-suited for a GPU, there is another aspect to consider: GPUs are ridiculously fast in terms of theoretical computational power (FLOPS, Floating Point Operations Per Second). But they are often throttled down by the memory bandwidth.

This leads to another classification of problems. Namely whether problems are memory bound or compute bound.

The first one refers to problems where the number of instructions that are done for each data element is low. For example, consider a parallel vector addition: You'll have to read two data elements, then perform a single addition, and then write the sum into the result vector. You will not see a speedup when doing this on the GPU, because the single addition does not compensate for the efforts of reading/writing the memory.

The second term, "compute bound", refers to problems where the number of instructions is high compared to the number of memory reads/writes. For example, consider a matrix multiplication: The number of instructions will be O(n^3) when n is the size of the matrix. In this case, one can expect that the GPU will outperform a CPU at a certain matrix size. Another example could be when many complex trigonometric computations (sine/cosine etc) are performed on "few" data elements.

As a rule of thumb: You can assume that reading/writing one data element from the "main" GPU memory has a latency of about 500 instructions....

Therefore, another key point for the performance of GPUs is data locality: If you have to read or write data (and in most cases, you will have to ;-)), then you should make sure that the data is kept as close as possible to the GPU cores. GPUs thus have certain memory areas (referred to as "local memory" or "shared memory") that usually is only a few KB in size, but particularly efficient for data that is about to be involved in a computation.

So to emphasize this again: GPU programming is an art, that is only remotely related to parallel programming on the CPU. Things like Threads in Java, with all the concurrency infrastructure like ThreadPoolExecutors, ForkJoinPools etc. might give the impression that you just have to split your work somehow and distribute it among several processors. On the GPU, you may encounter challenges on a much lower level: Occupancy, register pressure, shared memory pressure, memory coalescing ... just to name a few.

However, when you have a data-parallel, compute-bound problem to solve, the GPU is the way to go.


A general remark: Your specifically asked for CUDA. But I'd strongly recommend you to also have a look at OpenCL. It has several advantages. First of all, it's an vendor-independent, open industry standard, and there are implementations of OpenCL by AMD, Apple, Intel and NVIDIA. Additionally, there is a much broader support for OpenCL in the Java world. The only case where I'd rather settle for CUDA is when you want to use the CUDA runtime libraries, like CUFFT for FFT or CUBLAS for BLAS (Matrix/Vector operations). Although there are approaches for providing similar libraries for OpenCL, they can not directly be used from Java side, unless you create your own JNI bindings for these libraries.


You might also find it interesting to hear that in October 2012, the OpenJDK HotSpot group started the project "Sumatra": http://openjdk.java.net/projects/sumatra/ . The goal of this project is to provide GPU support directly in the JVM, with support from the JIT. The current status and first results can be seen in their mailing list at http://mail.openjdk.java.net/mailman/listinfo/sumatra-dev


However, a while ago, I collected some resources related to "Java on the GPU" in general. I'll summarize these again here, in no particular order.

(Disclaimer: I'm the author of http://jcuda.org/ and http://jocl.org/ )

(Byte)code translation and OpenCL code generation:

https://github.com/aparapi/aparapi : An open-source library that is created and actively maintained by AMD. In a special "Kernel" class, one can override a specific method which should be executed in parallel. The byte code of this method is loaded at runtime using an own bytecode reader. The code is translated into OpenCL code, which is then compiled using the OpenCL compiler. The result can then be executed on the OpenCL device, which may be a GPU or a CPU. If the compilation into OpenCL is not possible (or no OpenCL is available), the code will still be executed in parallel, using a Thread Pool.

https://github.com/pcpratts/rootbeer1 : An open-source library for converting parts of Java into CUDA programs. It offers dedicated interfaces that may be implemented to indicate that a certain class should be executed on the GPU. In contrast to Aparapi, it tries to automatically serialize the "relevant" data (that is, the complete relevant part of the object graph!) into a representation that is suitable for the GPU.

https://code.google.com/archive/p/java-gpu/ : A library for translating annotated Java code (with some limitations) into CUDA code, which is then compiled into a library that executes the code on the GPU. The Library was developed in the context of a PhD thesis, which contains profound background information about the translation process.

https://github.com/ochafik/ScalaCL : Scala bindings for OpenCL. Allows special Scala collections to be processed in parallel with OpenCL. The functions that are called on the elements of the collections can be usual Scala functions (with some limitations) which are then translated into OpenCL kernels.

Language extensions

http://www.ateji.com/px/index.html : A language extension for Java that allows parallel constructs (e.g. parallel for loops, OpenMP style) which are then executed on the GPU with OpenCL. Unfortunately, this very promising project is no longer maintained.

http://www.habanero.rice.edu/Publications.html (JCUDA) : A library that can translate special Java Code (called JCUDA code) into Java- and CUDA-C code, which can then be compiled and executed on the GPU. However, the library does not seem to be publicly available.

https://www2.informatik.uni-erlangen.de/EN/research/JavaOpenMP/index.html : Java language extension for for OpenMP constructs, with a CUDA backend

Java OpenCL/CUDA binding libraries

https://github.com/ochafik/JavaCL : Java bindings for OpenCL: An object-oriented OpenCL library, based on auto-generated low-level bindings

http://jogamp.org/jocl/www/ : Java bindings for OpenCL: An object-oriented OpenCL library, based on auto-generated low-level bindings

http://www.lwjgl.org/ : Java bindings for OpenCL: Auto-generated low-level bindings and object-oriented convenience classes

http://jocl.org/ : Java bindings for OpenCL: Low-level bindings that are a 1:1 mapping of the original OpenCL API

http://jcuda.org/ : Java bindings for CUDA: Low-level bindings that are a 1:1 mapping of the original CUDA API

Miscellaneous

http://sourceforge.net/projects/jopencl/ : Java bindings for OpenCL. Seem to be no longer maintained since 2010

http://www.hoopoe-cloud.com/ : Java bindings for CUDA. Seem to be no longer maintained


How to abort a Task like aborting a Thread (Thread.Abort method)?

Everyone knows (hopefully) its bad to terminate thread. The problem is when you don't own a piece of code you're calling. If this code is running in some do/while infinite loop , itself calling some native functions, etc. you're basically stuck. When this happens in your own code termination, stop or Dispose call, it's kinda ok to start shooting the bad guys (so you don't become a bad guy yourself).

So, for what it's worth, I've written those two blocking functions that use their own native thread, not a thread from the pool or some thread created by the CLR. They will stop the thread if a timeout occurs:

// returns true if the call went to completion successfully, false otherwise
public static bool RunWithAbort(this Action action, int milliseconds) => RunWithAbort(action, new TimeSpan(0, 0, 0, 0, milliseconds));
public static bool RunWithAbort(this Action action, TimeSpan delay)
{
    if (action == null)
        throw new ArgumentNullException(nameof(action));

    var source = new CancellationTokenSource(delay);
    var success = false;
    var handle = IntPtr.Zero;
    var fn = new Action(() =>
    {
        using (source.Token.Register(() => TerminateThread(handle, 0)))
        {
            action();
            success = true;
        }
    });

    handle = CreateThread(IntPtr.Zero, IntPtr.Zero, fn, IntPtr.Zero, 0, out var id);
    WaitForSingleObject(handle, 100 + (int)delay.TotalMilliseconds);
    CloseHandle(handle);
    return success;
}

// returns what's the function should return if the call went to completion successfully, default(T) otherwise
public static T RunWithAbort<T>(this Func<T> func, int milliseconds) => RunWithAbort(func, new TimeSpan(0, 0, 0, 0, milliseconds));
public static T RunWithAbort<T>(this Func<T> func, TimeSpan delay)
{
    if (func == null)
        throw new ArgumentNullException(nameof(func));

    var source = new CancellationTokenSource(delay);
    var item = default(T);
    var handle = IntPtr.Zero;
    var fn = new Action(() =>
    {
        using (source.Token.Register(() => TerminateThread(handle, 0)))
        {
            item = func();
        }
    });

    handle = CreateThread(IntPtr.Zero, IntPtr.Zero, fn, IntPtr.Zero, 0, out var id);
    WaitForSingleObject(handle, 100 + (int)delay.TotalMilliseconds);
    CloseHandle(handle);
    return item;
}

[DllImport("kernel32")]
private static extern bool TerminateThread(IntPtr hThread, int dwExitCode);

[DllImport("kernel32")]
private static extern IntPtr CreateThread(IntPtr lpThreadAttributes, IntPtr dwStackSize, Delegate lpStartAddress, IntPtr lpParameter, int dwCreationFlags, out int lpThreadId);

[DllImport("kernel32")]
private static extern bool CloseHandle(IntPtr hObject);

[DllImport("kernel32")]
private static extern int WaitForSingleObject(IntPtr hHandle, int dwMilliseconds);

Automatic vertical scroll bar in WPF TextBlock?

This is a simple solution to that question. The vertical scroll will be activated only when the text overflows.

<TextBox Text="Try typing some text here " ScrollViewer.VerticalScrollBarVisibility="Auto" TextWrapping="WrapWithOverflow" />

What is an abstract class in PHP?

Abstract Class
1. Contains an abstract method
2. Cannot be directly initialized
3. Cannot create an object of abstract class
4. Only used for inheritance purposes

Abstract Method
1. Cannot contain a body
2. Cannot be defined as private
3. Child classes must define the methods declared in abstract class

Example Code:

abstract class A {
    public function test1() {
        echo 'Hello World';
    }
    abstract protected function f1();
    abstract public function f2();
    protected function test2(){
        echo 'Hello World test';
    }
}

class B extends A {
    public $a = 'India';
    public function f1() {
        echo "F1 Method Call";
    }
    public function f2() {
        echo "F2 Method Call";
    }
}

$b = new B();
echo $b->test1() . "<br/>";
echo $b->a . "<br/>";
echo $b->test2() . "<br/>";
echo $b->f1() . "<br/>";
echo $b->f2() . "<br/>";

Output:

Hello World
India
Hello World test
F1 Method Call
F2 Method Call

To get total number of columns in a table in sql

The below query will display all the tables and corresponding column count in a database schema

SELECT Table_Name, count(*) as [No.of Columns]
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_schema = 'dbo' -- schema name
group by table_name

How to deal with "data of class uneval" error from ggplot2?

Another cause is accidentally putting the data=... inside the aes(...) instead of outside:

RIGHT:
ggplot(data=df[df$var7=='9-06',], aes(x=lifetime,y=rep_rate,group=mdcp,color=mdcp) ...)

WRONG:
ggplot(aes(data=df[df$var7=='9-06',],x=lifetime,y=rep_rate,group=mdcp,color=mdcp) ...)

In particular this can happen when you prototype your plot command with qplot(), which doesn't use an explicit aes(), then edit/copy-and-paste it into a ggplot()

qplot(data=..., x=...,y=..., ...)

ggplot(data=..., aes(x=...,y=...,...))

It's a pity ggplot's error message isn't Missing 'data' argument! instead of this cryptic nonsense, because that's what this message often means.

Build an iOS app without owning a mac?

Most framework like React Native and Ionic allows you to built on their server. Meaning that they can help you compile and provide you with and .ipa file.

The problem is you need Xcode or Application loader to submit your app to Apple App Store Connect. Both of these are only available on OSX. To overcome this solution you have 2 options that I am aware of

  1. Rent mac virtually. http://www.macincloud.com
  2. Use website that helps you to upload your app (You need to have .ipa file). http://www.connectuploader.com

Excel VBA Automation Error: The object invoked has disconnected from its clients

You must have used the object, released it ("disconnect"), and used it again. Release object only after you're finished with it, or when calling Form_Closing.

Importing a long list of constants to a Python file

Python doesn't have a preprocessor, nor does it have constants in the sense that they can't be changed - you can always change (nearly, you can emulate constant object properties, but doing this for the sake of constant-ness is rarely done and not considered useful) everything. When defining a constant, we define a name that's upper-case-with-underscores and call it a day - "We're all consenting adults here", no sane man would change a constant. Unless of course he has very good reasons and knows exactly what he's doing, in which case you can't (and propably shouldn't) stop him either way.

But of course you can define a module-level name with a value and use it in another module. This isn't specific to constants or anything, read up on the module system.

# a.py
MY_CONSTANT = ...

# b.py
import a
print a.MY_CONSTANT

Install dependencies globally and locally using package.json

This is a bit old but I ran into the requirement so here is the solution I came up with.

The Problem:

Our development team maintains many .NET web application products we are migrating to AngularJS/Bootstrap. VS2010 does not lend itself easily to custom build processes and my developers are routinely working on multiple releases of our products. Our VCS is Subversion (I know, I know. I'm trying to move to Git but my pesky marketing staff is so demanding) and a single VS solution will include several separate projects. I needed my staff to have a common method for initializing their development environment without having to install the same Node packages (gulp, bower, etc.) several times on the same machine.

TL;DR:

  1. Need "npm install" to install the global Node/Bower development environment as well as all locally required packages for a .NET product.

  2. Global packages should be installed only if not already installed.

  3. Local links to global packages must be created automatically.

The Solution:

We already have a common development framework shared by all developers and all products so I created a NodeJS script to install the global packages when needed and create the local links. The script resides in "....\SharedFiles" relative to the product base folder:

/*******************************************************************************
* $Id: npm-setup.js 12785 2016-01-29 16:34:49Z sthames $
* ==============================================================================
* Parameters: 'links' - Create links in local environment, optional.
* 
* <p>NodeJS script to install common development environment packages in global
* environment. <c>packages</c> object contains list of packages to install.</p>
* 
* <p>Including 'links' creates links in local environment to global packages.</p>
* 
* <p><b>npm ls -g --json</b> command is run to provide the current list of 
* global packages for comparison to required packages. Packages are installed 
* only if not installed. If the package is installed but is not the required 
* package version, the existing package is removed and the required package is 
* installed.</p>.
*
* <p>When provided as a "preinstall" script in a "package.json" file, the "npm
* install" command calls this to verify global dependencies are installed.</p>
*******************************************************************************/
var exec = require('child_process').exec;
var fs   = require('fs');
var path = require('path');

/*---------------------------------------------------------------*/
/* List of packages to install and 'from' value to pass to 'npm  */
/* install'. Value must match the 'from' field in 'npm ls -json' */
/* so this script will recognize a package is already installed. */
/*---------------------------------------------------------------*/
var packages = 
  {
  "bower"                      :                      "[email protected]", 
  "event-stream"               :               "[email protected]",
  "gulp"                       :                       "[email protected]",
  "gulp-angular-templatecache" : "[email protected]",
  "gulp-clean"                 :                 "[email protected]", 
  "gulp-concat"                :                "[email protected]",
  "gulp-debug"                 :                 "[email protected]",
  "gulp-filter"                :                "[email protected]",
  "gulp-grep-contents"         :         "[email protected]",
  "gulp-if"                    :                    "[email protected]", 
  "gulp-inject"                :                "[email protected]", 
  "gulp-minify-css"            :            "[email protected]",
  "gulp-minify-html"           :           "[email protected]",
  "gulp-minify-inline"         :         "[email protected]",
  "gulp-ng-annotate"           :           "[email protected]",
  "gulp-processhtml"           :           "[email protected]",
  "gulp-rev"                   :                   "[email protected]",
  "gulp-rev-replace"           :           "[email protected]",
  "gulp-uglify"                :                "[email protected]",
  "gulp-useref"                :                "[email protected]",
  "gulp-util"                  :                  "[email protected]",
  "lazypipe"                   :                   "[email protected]",
  "q"                          :                          "[email protected]",
  "through2"                   :                   "[email protected]",

  /*---------------------------------------------------------------*/
  /* fork of 0.2.14 allows passing parameters to main-bower-files. */
  /*---------------------------------------------------------------*/
  "bower-main"                 : "git+https://github.com/Pyo25/bower-main.git" 
  }

/*******************************************************************************
* run */
/**
* Executes <c>cmd</c> in the shell and calls <c>cb</c> on success. Error aborts.
* 
* Note: Error code -4082 is EBUSY error which is sometimes thrown by npm for 
* reasons unknown. Possibly this is due to antivirus program scanning the file 
* but it sometimes happens in cases where an antivirus program does not explain 
* it. The error generally will not happen a second time so this method will call 
* itself to try the command again if the EBUSY error occurs.
* 
* @param  cmd  Command to execute.
* @param  cb   Method to call on success. Text returned from stdout is input.
*******************************************************************************/
var run = function(cmd, cb)
  {
  /*---------------------------------------------*/
  /* Increase the maxBuffer to 10MB for commands */
  /* with a lot of output. This is not necessary */
  /* with spawn but it has other issues.         */
  /*---------------------------------------------*/
  exec(cmd, { maxBuffer: 1000*1024 }, function(err, stdout)
    {
    if      (!err)                   cb(stdout);
    else if (err.code | 0 == -4082) run(cmd, cb);
    else throw err;
    });
  };

/*******************************************************************************
* runCommand */
/**
* Logs the command and calls <c>run</c>.
*******************************************************************************/
var runCommand = function(cmd, cb)
  {
  console.log(cmd);
  run(cmd, cb);
  }

/*******************************************************************************
* Main line
*******************************************************************************/
var doLinks  = (process.argv[2] || "").toLowerCase() == 'links';
var names    = Object.keys(packages);
var name;
var installed;
var links;

/*------------------------------------------*/
/* Get the list of installed packages for   */
/* version comparison and install packages. */
/*------------------------------------------*/
console.log('Configuring global Node environment...')
run('npm ls -g --json', function(stdout)
  {
  installed = JSON.parse(stdout).dependencies || {};
  doWhile();
  });

/*--------------------------------------------*/
/* Start of asynchronous package installation */
/* loop. Do until all packages installed.     */
/*--------------------------------------------*/
var doWhile = function()
  {
  if (name = names.shift())
    doWhile0();
  }

var doWhile0 = function()
  {
  /*----------------------------------------------*/
  /* Installed package specification comes from   */
  /* 'from' field of installed packages. Required */
  /* specification comes from the packages list.  */
  /*----------------------------------------------*/
  var current  = (installed[name] || {}).from;
  var required =   packages[name];

  /*---------------------------------------*/
  /* Install the package if not installed. */
  /*---------------------------------------*/
  if (!current)
    runCommand('npm install -g '+required, doWhile1);

  /*------------------------------------*/
  /* If the installed version does not  */
  /* match, uninstall and then install. */
  /*------------------------------------*/
  else if (current != required)
    {
    delete installed[name];
    runCommand('npm remove -g '+name, function() 
      {
      runCommand('npm remove '+name, doWhile0);
      });
    }

  /*------------------------------------*/
  /* Skip package if already installed. */
  /*------------------------------------*/
  else
    doWhile1();
  };

var doWhile1 = function()
  {
  /*-------------------------------------------------------*/
  /* Create link to global package from local environment. */
  /*-------------------------------------------------------*/
  if (doLinks && !fs.existsSync(path.join('node_modules', name)))
    runCommand('npm link '+name, doWhile);
  else
    doWhile();
  };

Now if I want to update a global tool for our developers, I update the "packages" object and check in the new script. My developers check it out and either run it with "node npm-setup.js" or by "npm install" from any of the products under development to update the global environment. The whole thing takes 5 minutes.

In addition, to configure the environment for the a new developer, they must first only install NodeJS and GIT for Windows, reboot their computer, check out the "Shared Files" folder and any products under development, and start working.

The "package.json" for the .NET product calls this script prior to install:

{ 
"name"                    : "Books",
"description"             : "Node (npm) configuration for Books Database Web Application Tools",
"version"                 : "2.1.1",
"private"                 : true,
"scripts":
  {
  "preinstall"            : "node ../../SharedFiles/npm-setup.js links",
  "postinstall"           : "bower install"
  },
"dependencies": {}
}

Notes

  • Note the script reference requires forward slashes even in a Windows environment.

  • "npm ls" will give "npm ERR! extraneous:" messages for all packages locally linked because they are not listed in the "package.json" "dependencies".

Edit 1/29/16

The updated npm-setup.js script above has been modified as follows:

  • Package "version" in var packages is now the "package" value passed to npm install on the command line. This was changed to allow for installing packages from somewhere other than the registered repository.

  • If the package is already installed but is not the one requested, the existing package is removed and the correct one installed.

  • For reasons unknown, npm will periodically throw an EBUSY error (-4082) when performing an install or link. This error is trapped and the command re-executed. The error rarely happens a second time and seems to always clear up.

httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

Your hosts file does not include a valid FQDN, nor is localhost an FQDN. An FQDN must include a hostname part, as well as a domain name part. For example, the following is a valid FQDN:

host.server4-245.com

Choose an FQDN and include it both in your /etc/hosts file on both the IPv4 and IPv6 addresses you are using (in your case, localhost or 127.0.0.1), and change your ServerName in your httpd configuration to match.

/etc/hosts:

127.0.0.1    localhost.localdomain localhost host.server4-245.com
::1          localhost.localdomain localhost host.server4-245.com

httpd.conf:

ServerName host.server4-245.com

How to clear the interpreter console?

I might be late to the part but here is a very easy way to do it

Type:

def cls():
    os.system("cls")

So what ever you want to clear the screen just type in your code

cls()

Best way possible! (Credit : https://www.youtube.com/watch?annotation_id=annotation_3770292585&feature=iv&src_vid=bguKhMnvmb8&v=LtGEp9c6Z-U)

How to darken an image on mouseover?

Put a black, semitransparent, div on top of it.

Opening Chrome From Command Line

you can create batch file and insert into it the bellow line:

cmd /k start chrome "http://yourWebSite.com

after that you do just double click on this batch file.

how to fix java.lang.IndexOutOfBoundsException

for ( int i=0 ; i<=list.size() ; i++){
....}

By executing this for loop , the loop will execute with a thrown exception as IndexOutOfBoundException cause, suppose list size is 10 , so when index i will get to 10 i.e when i=10 the exception will be thrown cause index=size, i.e. i=size and as known that Java considers index starting from 0,1,2...etc the expression which Java agrees upon is index < size. So the solution for such exception is to make the statement in loop as i<list.size()

for ( int i=0 ; i<list.size() ; i++){
...}

SQL Plus change current directory

I don't think that you can change the directory in SQL*Plus.

Instead of changing directory, you can use @@filename, which reads in another script whose location is relative to the directory the current script is running in. For example, if you have two scripts

C:\Foo\Bar\script1.sql
C:\Foo\Bar\Baz\script2.sql

then script1.sql can run script2.sql if it contains the line

@@Baz\script2.sql

See this for more info about @@.

Get Cell Value from a DataTable in C#

You can iterate DataTable like this:

private void button1_Click(object sender, EventArgs e)
{
    for(int i = 0; i< dt.Rows.Count;i++)
        for (int j = 0; j <dt.Columns.Count ; j++)
        {
            object o = dt.Rows[i].ItemArray[j];
            //if you want to get the string
            //string s = o = dt.Rows[i].ItemArray[j].ToString();
        }
}

Depending on the type of the data in the DataTable cell, you can cast the object to whatever you want.

How to change bower's default components folder?

Something worth mentioning...

As noted above by other contributors, using a .bowerrc file with the JSON

{ "directory": "some/path" }

is necessary -- HOWEVER, you may run into an issue on Windows while creating that file. If Windows gives you a message imploring you to add a "file name", simply use a text editor / IDE such as Notepad++.

Add the JSON to an unnamed file, save it as .bowerrc -- you're good to go!

Probably an easy assumption, but I hope this save others the unnecessary headache :)

how to convert string into time format and add two hours

Being a fan of the Joda Time library, here's how you can do it that way using a Joda DateTime:

import org.joda.time.format.*;
import org.joda.time.*;

...    

String dateString = "2009-04-17 10:41:33";

// parse the string
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
DateTime dateTime = formatter.parseDateTime(dateString);

// add two hours
dateTime = dateTime.plusHours(2); // easier than mucking about with Calendar and constants

System.out.println(dateTime);

If you still need to use java.util.Date objects before/after this conversion, the Joda DateTime API provides some easy toDate() and toCalendar() methods for easy translation.

The Joda API provides so much more in the way of convenience over the Java Date/Calendar API.

How to ignore deprecation warnings in Python

None of these answers worked for me so I will post my way to solve this. I use the following at the beginning of my main.py script and it works fine.


Use the following as it is (copy-paste it):

def warn(*args, **kwargs):
    pass
import warnings
warnings.warn = warn

Example:

import "blabla"
import "blabla"

def warn(*args, **kwargs):
    pass
import warnings
warnings.warn = warn

# more code here...
# more code here...

Changing the row height of a datagridview

Try

datagridview.RowTemplate.MinimumHeight = 25;//25 is height.

I did that and it worked fine!

how to configuring a xampp web server for different root directory

  • Go to C:\xampp\apache\conf\httpd.conf
  • Open httpd.conf
  • Find tag : DocumentRoot "C:/xampp/htdocs"
  • Edit tag to : DocumentRoot "C:/xampp/htdocs/myproject/web"
  • Now find tag and change it to < Directory "C:/xampp/htdocs/myproject/web" >

  • Restart Your Apache

"undefined" function declared in another file?

If your source folder is structured /go/src/blog (assuming the name of your source folder is blog).

  1. cd /go/src/blog ... (cd inside the folder that has your package)
  2. go install
  3. blog

That should run all of your files at the same time, instead of you having to list the files manually or "bashing" a method on the command line.

Spring CrudRepository findByInventoryIds(List<Long> inventoryIdList) - equivalent to IN clause

findByInventoryIdIn(List<Long> inventoryIdList) should do the trick.

The HTTP request parameter format would be like so:

Yes ?id=1,2,3
No  ?id=1&id=2&id=3

The complete list of JPA repository keywords can be found in the current documentation listing. It shows that IsIn is equivalent – if you prefer the verb for readability – and that JPA also supports NotIn and IsNotIn.

How to add a hook to the application context initialization event?

Since Spring 4.2 you can use @EventListener (documentation)

@Component
class MyClassWithEventListeners {

    @EventListener({ContextRefreshedEvent.class})
    void contextRefreshedEvent() {
        System.out.println("a context refreshed event happened");
    }
}

How can I tell if a DOM element is visible in the current viewport?

This checks if an element is at least partially in view (vertical dimension):

function inView(element) {
    var box = element.getBoundingClientRect();
    return inViewBox(box);
}

function inViewBox(box) {
    return ((box.bottom < 0) || (box.top > getWindowSize().h)) ? false : true;
}


function getWindowSize() {
    return { w: document.body.offsetWidth || document.documentElement.offsetWidth || window.innerWidth, h: document.body.offsetHeight || document.documentElement.offsetHeight || window.innerHeight}
}

How do I display images from Google Drive on a website?

if you want to embedded Google drive images in your blogger or any sites then just follow the instructions : -

Blogger

  1. upload the image on google drive
  2. click on image and share with public
  3. <img src='https://drive.google.com/uc?export=view&amp;id=1OCx6mUEMbWcwCQbDePA5PeeOh'/>

How to construct a std::string from a std::vector<char>?

Well, the best way is to use the following constructor:

template<class InputIterator> string (InputIterator begin, InputIterator end);

which would lead to something like:

std::vector<char> v;
std::string str(v.begin(), v.end());

Only numbers. Input number in React

 <input
        className="input-Flied2"
        type="TEXT"
        name="userMobileNo"
        placeholder="Moble No"
        value={phonNumber}
        maxLength="10"
        onChange={handleChangeInput}
        required
      />

  const handleChangeInput = (e) => {
const re = /^[0-9\b]+$/; //rules
if (e.target.value === "" || re.test(e.target.value)) {
  setPhoneNumber(e.target.value);
}

};

Auto Resize Image in CSS FlexBox Layout and keeping Aspect Ratio?

img {max-width:100%;} is one way of doing this. Just add it to your CSS code.

http://jsfiddle.net/89dtxt6s/

How to return multiple values?

You can only return one value, but it can be an object that has multiple fields - ie a "value object". Eg

public class MyResult {
    int returnCode;
    String errorMessage;
    // etc
}

public MyResult someMethod() {
    // impl here
}

Determine Whether Integer Is Between Two Other Integers?

You want the output to print the given statement if and only if the number falls between 10,000 and 30,000.

Code should be;

if number >= 10000 and number <= 30000:
    print("you have to pay 5% taxes")

passing object by reference in C++

What seems to be confusing you is the fact that functions that are declared to be pass-by-reference (using the &) aren't called using actual addresses, i.e. &a.

The simple answer is that declaring a function as pass-by-reference:

void foo(int& x);

is all we need. It's then passed by reference automatically.

You now call this function like so:

int y = 5;
foo(y);

and y will be passed by reference.

You could also do it like this (but why would you? The mantra is: Use references when possible, pointers when needed) :

#include <iostream>
using namespace std;

class CDummy {
public:
    int isitme (CDummy* param);
};


int CDummy::isitme (CDummy* param)
{
    if (param == this) return true;
    else return false;
}

int main () {
    CDummy a;
    CDummy* b = &a;             // assigning address of a to b
    if ( b->isitme(&a) )        // Called with &a (address of a) instead of a
        cout << "yes, &a is b";
    return 0;
}

Output:

yes, &a is b

How to suppress warnings globally in an R Script

You want options(warn=-1). However, note that warn=0 is not the safest warning level and it should not be assumed as the current one, particularly within scripts or functions. Thus the safest way to temporary turn off warnings is:

oldw <- getOption("warn")
options(warn = -1)

[your "silenced" code]

options(warn = oldw)

Android toolbar center title and custom font

private void makeTitleCenter(String title, Toolbar toolbar) {
    if (title != null && !TextUtils.isEmpty(title.trim())) {
        final String tag = " ";
        if (getSupportActionBar() != null) {
            getSupportActionBar().setTitle(tag);
        }
        TextView titleTv = null;
        View leftBtn = null;
        for (int i = 0; i < toolbar.getChildCount(); i++) {
            View view = toolbar.getChildAt(i);
            CharSequence text = null;
            if (view instanceof TextView && (text = ((TextView) view).getText()) != null && text.equals(tag)) {
                titleTv = (TextView) view;
            } else if (view instanceof ImageButton) {
                leftBtn = view;
            }
        }
        if (titleTv != null) {
            final TextView fTitleTv = titleTv;
            final View fLeftBtn = leftBtn;
            fTitleTv.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                @Override
                public void onGlobalLayout() {
                    fTitleTv.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    int leftWidgetWidth = fLeftBtn != null ? fLeftBtn.getWidth() : 0;
                    fTitleTv.setPadding(DimenUtil.getResources().getDisplayMetrics().widthPixels / 2 - leftWidgetWidth - fTitleTv.getWidth() / 2, 0, 0, 0);
                    fTitleTv.requestLayout();
                }
            });
        }
    }
}

Angles between two n-dimensional vectors in Python

Note: all of the other answers here will fail if the two vectors have either the same direction (ex, (1, 0, 0), (1, 0, 0)) or opposite directions (ex, (-1, 0, 0), (1, 0, 0)).

Here is a function which will correctly handle these cases:

import numpy as np

def unit_vector(vector):
    """ Returns the unit vector of the vector.  """
    return vector / np.linalg.norm(vector)

def angle_between(v1, v2):
    """ Returns the angle in radians between vectors 'v1' and 'v2'::

            >>> angle_between((1, 0, 0), (0, 1, 0))
            1.5707963267948966
            >>> angle_between((1, 0, 0), (1, 0, 0))
            0.0
            >>> angle_between((1, 0, 0), (-1, 0, 0))
            3.141592653589793
    """
    v1_u = unit_vector(v1)
    v2_u = unit_vector(v2)
    return np.arccos(np.clip(np.dot(v1_u, v2_u), -1.0, 1.0))

What is the difference between square brackets and parentheses in a regex?

These regexes are equivalent (for matching purposes):

  • /^(7|8|9)\d{9}$/
  • /^[789]\d{9}$/
  • /^[7-9]\d{9}$/

The explanation:

  • (a|b|c) is a regex "OR" and means "a or b or c", although the presence of brackets, necessary for the OR, also captures the digit. To be strictly equivalent, you would code (?:7|8|9) to make it a non capturing group.

  • [abc] is a "character class" that means "any character from a,b or c" (a character class may use ranges, e.g. [a-d] = [abcd])

The reason these regexes are similar is that a character class is a shorthand for an "or" (but only for single characters). In an alternation, you can also do something like (abc|def) which does not translate to a character class.

How to calculate difference between two dates in oracle 11g SQL

You can use this:

SET FEEDBACK OFF;
SET SERVEROUTPUT ON;

DECLARE
  V_START_DATE  CHAR(17) := '28/03/16 17:20:00';
  V_END_DATE    CHAR(17) := '30/03/16 17:50:10';
  V_DATE_DIFF   VARCHAR2(17);

BEGIN

SELECT
  (TO_NUMBER( SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 02, 9)) * 24) +
  (TO_NUMBER( SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 12, 2)))  || 
              SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 14, 6) AS "HH24:MI:SS"
  INTO V_DATE_DIFF
FROM 
  DUAL;

DBMS_OUTPUT.PUT_LINE(V_DATE_DIFF);
END;

How to start up spring-boot application via command line?

1.Run Spring Boot app with java -jar command

To run your Spring Boot app from a command line in a Terminal window you can use java -jar command. This is provided your Spring Boot app was packaged as an executable jar file.

java -jar target/app-0.0.1-SNAPSHOT.jar

2.Run Spring Boot app using Maven

You can also use Maven plugin to run your Spring Boot app. Use the below command to run your Spring Boot app with Maven plugin:

mvn spring-boot:run

3.Run Spring Boot App with Gradle

And if you use Gradle you can run the Spring Boot app with the following command:

gradle bootRun

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured

If you added "spring-boot-starter-data-jpa" dependency in pom.xml, Please add respective database in dependency like h2 and etc.

How do shift operators work in Java?

It will shift the bits by padding that many 0's.

For ex,

  • binary 10 which is digit 2 left shift by 2 is 1000 which is digit 8
  • binary 10 which is digit 2 left shift by 3 is 10000 which is digit 16

JPA With Hibernate Error: [PersistenceUnit: JPA] Unable to build EntityManagerFactory

Use above annotation if someone is facing :--org.hibernate.jpa.HibernatePersistenceProvider persistence provider when it attempted to create the container entity manager factory for the paymentenginePU persistence unit. The following error occurred: [PersistenceUnit: paymentenginePU] Unable to build Hibernate SessionFactory ** This is a solution if you are using Audit table.@Audit

Use:- @Audited(targetAuditMode = RelationTargetAuditMode.NOT_AUDITED) on superclass.

Integer division: How do you produce a double?

Best way to do this is

int i = 3;
Double d = i * 1.0;

d is 3.0 now.

Can I map a hostname *and* a port with /etc/hosts?

No, that's not possible. The port is not part of the hostname, so it has no meaning in the hosts-file.

CSS force new line

How about with a :before pseudoelement:

a:before {
  content: '\a';
  white-space: pre;
}

What is the equivalent of Java static methods in Kotlin?

You can achieve the static functionality in Kotlin by Companion Objects

  • Adding companion to the object declaration allows for adding the static functionality to an object even though the actual static concept does not exist in Kotlin.
  • A companion object can access all members of the class too, including the private constructors.
  • A companion object is initialized when the class is instantiated.
  • A companion object cannot be declared outside the class.

    class MyClass{
    
        companion object {
    
            val staticField = "This is an example of static field Object Decleration"
    
            fun getStaticFunction(): String {
                return "This is example of static function for Object Decleration"
            }
    
        }
    }
    

Members of the companion object can be called by using simply the class name as the qualifier:

Output:

MyClass.staticField // This is an example of static field Object Decleration

MyClass.getStaticFunction() : // This is an example of static function for Object Decleration

MVC Razor view nested foreach's model

You can simply use EditorTemplates to do that, you need to create a directory named "EditorTemplates" in your controller's view folder and place a seperate view for each of your nested entities (named as entity class name)

Main view :

@model ViewModels.MyViewModels.Theme

@Html.LabelFor(Model.Theme.name)
@Html.EditorFor(Model.Theme.Categories)

Category view (/MyController/EditorTemplates/Category.cshtml) :

@model ViewModels.MyViewModels.Category

@Html.LabelFor(Model.Name)
@Html.EditorFor(Model.Products)

Product view (/MyController/EditorTemplates/Product.cshtml) :

@model ViewModels.MyViewModels.Product

@Html.LabelFor(Model.Name)
@Html.EditorFor(Model.Orders)

and so on

this way Html.EditorFor helper will generate element's names in an ordered manner and therefore you won't have any further problem for retrieving the posted Theme entity as a whole

Print all properties of a Python Class

Just try beeprint

it prints something like this:

instance(Animal):
    legs: 2,
    name: 'Dog',
    color: 'Spotted',
    smell: 'Alot',
    age: 10,
    kids: 0,

I think is exactly what you need.

Access props inside quotes in React JSX

Best practices are to add getter method for that :

getImageURI() {
  return "images/" + this.props.image;
}

<img className="image" src={this.getImageURI()} />

Then , if you have more logic later on, you can maintain the code smoothly.

Floating Point Exception C++ Why and what is it?

Since this page is the number 1 result for the google search "c++ floating point exception", I want to add another thing that can cause such a problem: use of undefined variables.

JQuery to load Javascript file dynamically

Yes, use getScript instead of document.write - it will even allow for a callback once the file loads.

You might want to check if TinyMCE is defined, though, before including it (for subsequent calls to 'Add Comment') so the code might look something like this:

$('#add_comment').click(function() {
    if(typeof TinyMCE == "undefined") {
        $.getScript('tinymce.js', function() {
            TinyMCE.init();
        });
    }
});

Assuming you only have to call init on it once, that is. If not, you can figure it out from here :)

How to set the image from drawable dynamically in android?

int[] phptr=new int[5];

adding image pointer to array

for(int lv=0;lv<3;lv++)
    {
        String id="a"+String.valueOf(lv+1);
        phptr[lv]= getResources().getIdentifier(id, "drawable", getPackageName());
    }

for(int loopvariable=0;loopvariable<3;loopvariable++) 
    {
        et[loopvariable] = findViewById(p[loopvariable]);
    }



for(int lv=0;lv<3;lv++)
    {
        et[k].setImageResource(phptr[k]);
    }

html/css buttons that scroll down to different div sections on a webpage

try this:

<input type="button" onClick="document.getElementById('middle').scrollIntoView();" />

Capture close event on Bootstrap Modal

Though is answered in another stack overflow question Bind a function to Twitter Bootstrap Modal Close but for visual feel here is more detailed answer.

Source: http://getbootstrap.com/javascript/#modals-events

How to send a correct authorization header for basic authentication

If you are in a browser environment you can also use btoa.

btoa is a function which takes a string as argument and produces a Base64 encoded ASCII string. Its supported by 97% of browsers.

Example:

> "Basic " + btoa("billy"+":"+"secretpassword")
< "Basic YmlsbHk6c2VjcmV0cGFzc3dvcmQ="

You can then add Basic YmlsbHk6c2VjcmV0cGFzc3dvcmQ= to the authorization header.

Note that the usual caveats about HTTP BASIC auth apply, most importantly if you do not send your traffic over https an eavesdropped can simply decode the Base64 encoded string thus obtaining your password.

This security.stackexchange.com answer gives a good overview of some of the downsides.

Change application's starting activity

 <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

validate natural input number with ngpattern

This is working

<form name="myform" ng-submit="create()">
    <input type="number"
           name="price_field"
           ng-model="price"
           require
           ng-pattern="/^\d{0,9}(\.\d{1,9})?$/">
    <span  ng-show="myform.price_field.$error.pattern">Not valid number!</span>
    <input type="submit" class="btn">
 </form>

How do I calculate someone's age in Java?

public class CalculateAge { 

private int age;

private void setAge(int age){

    this.age=age;

}
public void calculateAge(Date date){

    Calendar calendar=Calendar.getInstance();

    Calendar calendarnow=Calendar.getInstance();    

    calendarnow.getTimeZone();

    calendar.setTime(date);

    int getmonth= calendar.get(calendar.MONTH);

    int getyears= calendar.get(calendar.YEAR);

    int currentmonth= calendarnow.get(calendarnow.MONTH);

    int currentyear= calendarnow.get(calendarnow.YEAR);

    int age = ((currentyear*12+currentmonth)-(getyears*12+getmonth))/12;

    setAge(age);
}
public int getAge(){

    return this.age;

}

Java AES encryption and decryption

Here is the implementation that was mentioned above:

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.StringUtils;

try
{
    String passEncrypt = "my password";
    byte[] saltEncrypt = "choose a better salt".getBytes();
    int iterationsEncrypt = 10000;
    SecretKeyFactory factoryKeyEncrypt = SecretKeyFactory
            .getInstance("PBKDF2WithHmacSHA1");
    SecretKey tmp = factoryKeyEncrypt.generateSecret(new PBEKeySpec(
            passEncrypt.toCharArray(), saltEncrypt, iterationsEncrypt,
            128));
    SecretKeySpec encryptKey = new SecretKeySpec(tmp.getEncoded(),
            "AES");

    Cipher aesCipherEncrypt = Cipher
            .getInstance("AES/ECB/PKCS5Padding");
    aesCipherEncrypt.init(Cipher.ENCRYPT_MODE, encryptKey);

    // get the bytes
    byte[] bytes = StringUtils.getBytesUtf8(toEncodeEncryptString);

    // encrypt the bytes
    byte[] encryptBytes = aesCipherEncrypt.doFinal(bytes);

    // encode 64 the encrypted bytes
    String encoded = Base64.encodeBase64URLSafeString(encryptBytes);

    System.out.println("e: " + encoded);

    // assume some transport happens here

    // create a new string, to make sure we are not pointing to the same
    // string as the one above
    String encodedEncrypted = new String(encoded);

    //we recreate the same salt/encrypt as if its a separate system
    String passDecrypt = "my password";
    byte[] saltDecrypt = "choose a better salt".getBytes();
    int iterationsDecrypt = 10000;
    SecretKeyFactory factoryKeyDecrypt = SecretKeyFactory
            .getInstance("PBKDF2WithHmacSHA1");
    SecretKey tmp2 = factoryKeyDecrypt.generateSecret(new PBEKeySpec(passDecrypt
            .toCharArray(), saltDecrypt, iterationsDecrypt, 128));
    SecretKeySpec decryptKey = new SecretKeySpec(tmp2.getEncoded(), "AES");

    Cipher aesCipherDecrypt = Cipher.getInstance("AES/ECB/PKCS5Padding");
            aesCipherDecrypt.init(Cipher.DECRYPT_MODE, decryptKey);

    //basically we reverse the process we did earlier

    // get the bytes from encodedEncrypted string
    byte[] e64bytes = StringUtils.getBytesUtf8(encodedEncrypted);

    // decode 64, now the bytes should be encrypted
    byte[] eBytes = Base64.decodeBase64(e64bytes);

    // decrypt the bytes
    byte[] cipherDecode = aesCipherDecrypt.doFinal(eBytes);

    // to string
    String decoded = StringUtils.newStringUtf8(cipherDecode);

    System.out.println("d: " + decoded);

}
catch (Exception e)
{
    e.printStackTrace();
}

Change old commit message on Git

FWIW, git rebase interactive now has a "reword" option, which makes this much less painful!

Adjust plot title (main) position

We can use title() function with negative line value to bring down the title.

See this example:

plot(1, 1)
title("Title", line = -2)

enter image description here

Why do I get a "permission denied" error while installing a gem?

Install rbenv or rvm as your Ruby version manager (I prefer rbenv) via homebrew (ie. brew update & brew install rbenv) but then for example in rbenv's case make sure to add rbenv to your $PATH as instructed here and here.

For a deeper explanation on how rbenv works I recommend this.

Check if an element is present in an array

Code:

function isInArray(value, array) {
  return array.indexOf(value) > -1;
}

Execution:

isInArray(1, [1,2,3]); // true

Update (2017):

In modern browsers which follow the ECMAScript 2016 (ES7) standard, you can use the function Array.prototype.includes, which makes it way more easier to check if an item is present in an array:

_x000D_
_x000D_
const array = [1, 2, 3];_x000D_
const value = 1;_x000D_
const isInArray = array.includes(value);_x000D_
console.log(isInArray); // true
_x000D_
_x000D_
_x000D_

How to check if variable's type matches Type stored in a variable

You need to see if the Type of your instance is equal to the Type of the class. To get the type of the instance you use the GetType() method:

 u.GetType().Equals(t);

or

 u.GetType.Equals(typeof(User));

should do it. Obviously you could use '==' to do your comparison if you prefer.

Maven: add a dependency to a jar by relative path

This is working for me: Let's say I have this dependency

<dependency>
    <groupId>com.company.app</groupId>
    <artifactId>my-library</artifactId>
    <version>1.0</version>
    <scope>system</scope>
    <systemPath>${project.basedir}/lib/my-library.jar</systemPath>
</dependency>

Then, add the class-path for your system dependency manually like this

<Class-Path>libs/my-library-1.0.jar</Class-Path>

Full config:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>2.4</version>
    <configuration>
        <archive>
            <manifestEntries>
                <Build-Jdk>${jdk.version}</Build-Jdk>
                <Implementation-Title>${project.name}</Implementation-Title>
                <Implementation-Version>${project.version}</Implementation-Version>
                <Specification-Title>${project.name} Library</Specification-Title>
                <Specification-Version>${project.version}</Specification-Version>
                <Class-Path>libs/my-library-1.0.jar</Class-Path>
            </manifestEntries>
            <manifest>
                <addClasspath>true</addClasspath>
                <mainClass>com.company.app.MainClass</mainClass>
                <classpathPrefix>libs/</classpathPrefix>
            </manifest>
        </archive>
    </configuration>
</plugin>
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <version>2.5.1</version>
    <executions>
        <execution>
            <id>copy-dependencies</id>
            <phase>package</phase>
            <goals>
                <goal>copy-dependencies</goal>
            </goals>
            <configuration>
                <outputDirectory>${project.build.directory}/libs/</outputDirectory>
            </configuration>
        </execution>
    </executions>
</plugin>

Display Bootstrap Modal using javascript onClick

You don't need an onclick. Assuming you're using Bootstrap 3 Bootstrap 3 Documentation

<div class="span4 proj-div" data-toggle="modal" data-target="#GSCCModal">Clickable content, graphics, whatever</div>

<div id="GSCCModal" class="modal fade" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
 <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;  </button>
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

If you're using Bootstrap 2, you'd follow the markup here: http://getbootstrap.com/2.3.2/javascript.html#modals

Using Server.MapPath() inside a static field in ASP.NET MVC

Try HostingEnvironment.MapPath, which is static.

See this SO question for confirmation that HostingEnvironment.MapPath returns the same value as Server.MapPath: What is the difference between Server.MapPath and HostingEnvironment.MapPath?

Removing nan values from an array

If you're using numpy

# first get the indices where the values are finite
ii = np.isfinite(x)

# second get the values
x = x[ii]

How to dismiss the dialog with click on outside of the dialog?

This method should completely avoid activities below the grey area retrieving click events.

Remove this line if you have it:

window.setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL, WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL);

Put this on your activity created

getWindow().setFlags(LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH, LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH);

then override the touch event with this

@Override
public boolean onTouchEvent(MotionEvent ev)
{
    if(MotionEvent.ACTION_DOWN == ev.getAction())
    {
        Rect dialogBounds = new Rect();
        getWindow().getDecorView().getHitRect(dialogBounds);
        if (!dialogBounds.contains((int) ev.getX(), (int) ev.getY())) {
            // You have clicked the grey area
            displayYourDialog();
            return false; // stop activity closing
        }
    }

    // Touch events inside are fine.
    return super.onTouchEvent(ev);
}

Why does a base64 encoded string have an = sign at the end

1: No.

2: As a short answer: The 65th character ("=" sign) is used only as a complement in the final process of encoding a message.

You will not have a '=' sign if your string has a multiple of 3 characters number, because Base64 encoding takes each three bytes (8 bits) and represents them as four printable characters in the ASCII standard.

Details:

(a) If you want to encode

ABCDEFG <=> [ABC] [DEF] [G

Base64 will deal with the first block (producing 4 characters) and the second (as they are complete). But for the third it will add a double == in the output in order to complete the 4 needed characters. Thus, the result will be QUJD REVG Rw== (without spaces).

(b) If you want to encode

ABCDEFGH <=> [ABC] [DEF] [GH

similarly, it will add just a single = in the end of the output to get 4 characters.

The result will be QUJD REVG R0g= (without spaces).

remove all special characters in java

use [\\W+] or "[^a-zA-Z0-9]" as regex to match any special characters and also use String.replaceAll(regex, String) to replace the spl charecter with an empty string. remember as the first arg of String.replaceAll is a regex you have to escape it with a backslash to treat em as a literal charcter.

          String c= "hjdg$h&jk8^i0ssh6";
        Pattern pt = Pattern.compile("[^a-zA-Z0-9]");
        Matcher match= pt.matcher(c);
        while(match.find())
        {
            String s= match.group();
        c=c.replaceAll("\\"+s, "");
        }
        System.out.println(c);

How to write an async method with out parameter?

You cannot have ref or out parameters in async methods (as was already noted).

This screams for some modelling in the data moving around:

public class Data
{
    public int Op {get; set;}
    public int Result {get; set;}
}

public async void Method1()
{
    Data data = await GetDataTaskAsync();
    // use data.Op and data.Result from here on
}

public async Task<Data> GetDataTaskAsync()
{
    var returnValue = new Data();
    // Fill up returnValue
    return returnValue;
}

You gain the ability to reuse your code more easily, plus it's way more readable than variables or tuples.

What is the "-->" operator in C/C++?

It's a combination of two operators. First -- is for decrementing the value, and > is for checking whether the value is greater than the right-hand operand.

#include<stdio.h>

int main()
{
    int x = 10;

    while (x-- > 0)
        printf("%d ",x);

    return 0;
}

The output will be:

9 8 7 6 5 4 3 2 1 0            

How to make a node.js application run permanently?

Try pm2 to make your application run forever.

npm install -g pm2

and then use

pm2 start server.js

to list and stop apps, use commnds

pm2 list

pm2 stop 0

How do I overload the [] operator in C#

public int this[int index]
{
    get => values[index];
}

How to install a private NPM module without my own registry?

I had this same problem, and after some searching around, I found Reggie (https://github.com/mbrevoort/node-reggie). It looks pretty solid. It allows for lightweight publishing of NPM modules to private servers. Not perfect (no authentication upon installation), and it's still really young, but I tested it locally, and it seems to do what it says it should do.

That is... (and this just from their docs)

npm install -g reggie
reggie-server -d ~/.reggie

then cd into your module directory and...

reggie -u http://<host:port> publish 
reggie -u http://127.0.0.1:8080 publish 

finally, you can install packages from reggie just by using that url either in a direct npm install command, or from within a package.json... like so

npm install http://<host:port>/package/<name>/<version>
npm install http://<host:port>/package/foo/1.0.0

or..

dependencies: {
    "foo": "http://<host:port>/package/foo/1.0.0"
}

xampp MySQL does not start

The is a simple and faster way to solve the problem.

You don't need to open a services or write any cmd code just follow my steps:

  1. from XAMPP control panel click Explorer button

  2. from directory find mysql_stop.bat file and run it.

Thats all!! super easy.

Refresh your netstat list, you will see that it has gone.

please make it as best answer.

How to install the current version of Go in Ubuntu Precise

[Updated (previous answer no longer applied)]

For fetching the latest version:

sudo add-apt-repository ppa:longsleep/golang-backports
sudo apt update
sudo apt install golang-go

Also see the wiki

Remove file from SVN repository without deleting local copy

In TortoiseSVN, you can also Shift + right-click to get a menu that includes "Delete (keep local)".

Postgresql - change the size of a varchar column to lower length

I was facing the same problem trying to truncate a VARCHAR from 32 to 8 and getting the ERROR: value too long for type character varying(8). I want to stay as close to SQL as possible because I'm using a self-made JPA-like structure that we might have to switch to different DBMS according to customer's choices (PostgreSQL being the default one). Hence, I don't want to use the trick of altering System tables.

I ended using the USING statement in the ALTER TABLE:

ALTER TABLE "MY_TABLE" ALTER COLUMN "MyColumn" TYPE varchar(8)
USING substr("MyColumn", 1, 8)

As @raylu noted, ALTER acquires an exclusive lock on the table so all other operations will be delayed until it completes.

Objective-C and Swift URL encoding

int strLength = 0;
NSString *urlStr = @"http://www";
NSLog(@" urlStr : %@", urlStr );
NSMutableString *mutableUrlStr = [urlStr mutableCopy];
NSLog(@" mutableUrlStr : %@", mutableUrlStr );
strLength = [mutableUrlStr length];
[mutableUrlStr replaceOccurrencesOfString:@":" withString:@"%3A" options:NSCaseInsensitiveSearch range:NSMakeRange(0, strLength)];
NSLog(@" mutableUrlStr : %@", mutableUrlStr );
strLength = [mutableUrlStr length];
[mutableUrlStr replaceOccurrencesOfString:@"/" withString:@"%2F" options:NSCaseInsensitiveSearch range:NSMakeRange(0, strLength)];
NSLog(@" mutableUrlStr : %@", mutableUrlStr );

Drop all data in a pandas dataframe

My favorite:

df = df.iloc[0:0]

But be aware df.index.max() will be nan. To add items I use:

df.loc[0 if math.isnan(df.index.max()) else df.index.max() + 1] = data

Load local images in React.js

If you want load image with a local relative URL as you are doing. React project has a default public folder. You should put your images folder inside. It will work.

enter image description here

Remove first 4 characters of a string with PHP

You can use this by php function with substr function

<?php
function removeChar($value) {
    $value2 = substr($value, 4); 
    return $value2;
}

echo removeChar("Dummy Text. Sample Text.");
?>

You get this result: " y Text. Sample Text. "

Modifying a query string without reloading the page

Then the history API is exactly what you are looking for. If you wish to support legacy browsers as well, then look for a library that falls back on manipulating the URL's hash tag if the browser doesn't provide the history API.

Why won't my PHP app send a 404 error?

That is correct behaviour, it's up to you to create the contents for the 404 page.
The 404 header is used by spiders and download-managers to determine if the file exists.
(A page with a 404 header won't be indexed by google or other search-engines)

Normal users however don't look at http-headers and use the page as a normal page.

How do you append an int to a string in C++?

Another possibility is Boost.Format:

#include <boost/format.hpp>
#include <iostream>
#include <string>

int main() {
  int i = 4;
  std::string text = "Player";
  std::cout << boost::format("%1% %2%\n") % text % i;
}

Rails find_or_create_by more than one attribute?

By passing a block to find_or_create, you can pass additional parameters that will be added to the object if it is created new. This is useful if you are validating the presence of a field that you aren't searching by.

Assuming:

class GroupMember < ActiveRecord::Base
    validates_presence_of :name
end

then

GroupMember.where(:member_id => 4, :group_id => 7).first_or_create { |gm| gm.name = "John Doe" }

will create a new GroupMember with the name "John Doe" if it doesn't find one with member_id 4 and group_id 7

Defining an abstract class without any abstract methods

Yes we can have an abstract class without Abstract Methods as both are independent concepts. Declaring a class abstract means that it can not be instantiated on its own and can only be sub classed. Declaring a method abstract means that Method will be defined in the subclass.

How can I find the location of origin/master in git, and how do I change it?

I had a problem that was similar to this where my working directory was ahead of origin by X commits but the git pull was resulting in Everything up-to-date. I did manage to fix it by following this advice. I'm posting this here in case it helps someone else with a similar problem.

The basic fix is as follows:

$ git push {remote} {localbranch}:{remotebranch}

Where the words in brackets should be replaced by your remote name, your local branch name and your remote branch name. e.g.

$ git push origin master:master

How to use '-prune' option of 'find' in sh?

If you read all the good answers here my understanding now is that the following all return the same results:

find . -path ./dir1\*  -prune -o -print

find . -path ./dir1  -prune -o -print

find . -path ./dir1\*  -o -print
#look no prune at all!

But the last one will take a lot longer as it still searches out everything in dir1. I guess the real question is how to -or out unwanted results without actually searching them.

So I guess prune means don't decent past matches but mark it as done...

http://www.gnu.org/software/findutils/manual/html_mono/find.html "This however is not due to the effect of the ‘-prune’ action (which only prevents further descent, it doesn't make sure we ignore that item). Instead, this effect is due to the use of ‘-o’. Since the left hand side of the “or” condition has succeeded for ./src/emacs, it is not necessary to evaluate the right-hand-side (‘-print’) at all for this particular file."

In Java, what does NaN mean?

Not a valid floating-point value (e.g. the result of division by zero)

http://en.wikipedia.org/wiki/NaN

What is the right way to debug in iPython notebook?

The %pdb magic command is good to use as well. Just say %pdb on and subsequently the pdb debugger will run on all exceptions, no matter how deep in the call stack. Very handy.

If you have a particular line that you want to debug, just raise an exception there (often you already are!) or use the %debug magic command that other folks have been suggesting.

node.js TypeError: path must be absolute or specify root to res.sendFile [failed to parse JSON]

The error is pretty straightforward. Most likely the reason is that your index.html file is not in the root directory.

Or if it is in the root directory then the relative referencing is not working.

So you need to tell the server exact location of your file. This could be done by using dirname method in NodeJs. Just replace your code with this one:

 app.get('/', function(req, res){
  res.sendFile(__dirname + '/index.html');
});

Make sure that your add the slash "/" symbol before your homepage. Otherwise your path will become: rootDirectoryindex.html

Whereas you want it to be: rootDirectory/index.html

Get Selected value of a Combobox

A simpler way to get the selected value from a ComboBox control is:

Private Sub myComboBox_Change()
  msgbox "You selected: " + myComboBox.SelText
End Sub

Retrieving JSON Object Literal from HttpServletRequest

Converting the retreived data from the request object to json object is as below using google-gson

Gson gson = new Gson();
ABCClass c1 = gson.fromJson(data, ABCClass.class);

//ABC class is a class whose strcuture matches to the data variable retrieved

How to check a boolean condition in EL?

You can check this way too

<c:if test="${theBooleanVariable ne true}">It's false!</c:if>

Xcode 4: How do you view the console?

If you just want to have the log output display when you run your app then you can go into XCode4 preferences -> Alerts and click on 'Run starts' on the left hand column.

Then select 'Show Debugger' and when you run the app the NSLog output will be displayed below the editor pane.

This way you don't have to select on the 'up arrow' button at the bottom bar.

Add Expires headers

The easiest way to add these headers is a .htaccess file that adds some configuration to your server. If the assets are hosted on a server that you don't control, there's nothing you can do about it.

Note that some hosting providers will not let you use .htaccess files, so check their terms if it doesn't seem to work.

The HTML5Boilerplate project has an excellent .htaccess file that covers the necessary settings. See the relevant part of the file at their Github repository

These are the important bits

# ----------------------------------------------------------------------
# Expires headers (for better cache control)
# ----------------------------------------------------------------------

# These are pretty far-future expires headers.
# They assume you control versioning with filename-based cache busting
# Additionally, consider that outdated proxies may miscache
# www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/

# If you don't use filenames to version, lower the CSS and JS to something like
# "access plus 1 week".

<IfModule mod_expires.c>
  ExpiresActive on

# Your document html
  ExpiresByType text/html "access plus 0 seconds"

# Media: images, video, audio
  ExpiresByType audio/ogg "access plus 1 month"
  ExpiresByType image/gif "access plus 1 month"
  ExpiresByType image/jpeg "access plus 1 month"
  ExpiresByType image/png "access plus 1 month"
  ExpiresByType video/mp4 "access plus 1 month"
  ExpiresByType video/ogg "access plus 1 month"
  ExpiresByType video/webm "access plus 1 month"

# CSS and JavaScript
  ExpiresByType application/javascript "access plus 1 year"
  ExpiresByType text/css "access plus 1 year"
</IfModule>

They have documented what that file does, the most important bit is that you need to rename your CSS and Javascript files whenever they change, because your visitor's browsers will not check them again for a year, once they are cached.

HTML Display Current date

This helped me:

<p>Date/Time: <span id="datetime"></span></p><script>var dt = new Date();
document.getElementById("datetime").innerHTML=dt.toLocaleString();</script>    

How to add external library in IntelliJ IDEA?

Easier procedure on latest versions:

  • Copy jar to libs directory in the app (you can create the directory it if not there)
  • Refresh project so libs show up in the structure (right click on project top level, refresh/synchronize)
  • Expand libs and right click on the jar
  • Select "Add as Library"

Done

How to merge rows in a column into one cell in excel?

Use VBA's already existing Join function. VBA functions aren't exposed in Excel, so I wrap Join in a user-defined function that exposes its functionality. The simplest form is:

Function JoinXL(arr As Variant, Optional delimiter As String = " ")
    'arr must be a one-dimensional array.
    JoinXL = Join(arr, delimiter)
End Function

Example usage:

=JoinXL(TRANSPOSE(A1:A4)," ") 

entered as an array formula (using Ctrl-Shift-Enter).

enter image description here


Now, JoinXL accepts only one-dimensional arrays as input. In Excel, ranges return two-dimensional arrays. In the above example, TRANSPOSE converts the 4×1 two-dimensional array into a 4-element one-dimensional array (this is the documented behaviour of TRANSPOSE when it is fed with a single-column two-dimensional array).

For a horizontal range, you would have to do a double TRANSPOSE:

=JoinXL(TRANSPOSE(TRANSPOSE(A1:D1)))

The inner TRANSPOSE converts the 1×4 two-dimensional array into a 4×1 two-dimensional array, which the outer TRANSPOSE then converts into the expected 4-element one-dimensional array.

enter image description here

This usage of TRANSPOSE is a well-known way of converting 2D arrays into 1D arrays in Excel, but it looks terrible. A more elegant solution would be to hide this away in the JoinXL VBA function.

How to place Text and an Image next to each other in HTML?

img {
    float:left;
}
h3 {
    float:right;
}

jsFiddle example

Note that you will probably want to use the style clear:both on whatever elements comes after the code you provided so that it doesn't slide up directly beneath the floated elements.

Converting Long to Date in Java returns 1970

1220227200 corresponds to Jan 15 1980 (and indeed new Date(1220227200).toString() returns "Thu Jan 15 03:57:07 CET 1970"). If you pass a long value to a date, that is before 01/01/1970 it will in fact return a date of 01/01/1970. Make sure that your values are not in this situation (lower than 82800000).

Sorting objects by property values

I have wrote this simple function for myself:

function sortObj(list, key) {
    function compare(a, b) {
        a = a[key];
        b = b[key];
        var type = (typeof(a) === 'string' ||
                    typeof(b) === 'string') ? 'string' : 'number';
        var result;
        if (type === 'string') result = a.localeCompare(b);
        else result = a - b;
        return result;
    }
    return list.sort(compare);
}

for example you have list of cars:

var cars= [{brand: 'audi', speed: 240}, {brand: 'fiat', speed: 190}];
var carsSortedByBrand = sortObj(cars, 'brand');
var carsSortedBySpeed = sortObj(cars, 'speed');

Centering a background image, using CSS

simply replace

background-image:url(../images/images2.jpg) no-repeat;

with

background:url(../images/images2.jpg)  center;

Best practices to test protected methods with PHPUnit

teastburn has the right approach. Even simpler is to call the method directly and return the answer:

class PHPUnitUtil
{
  public static function callMethod($obj, $name, array $args) {
        $class = new \ReflectionClass($obj);
        $method = $class->getMethod($name);
        $method->setAccessible(true);
        return $method->invokeArgs($obj, $args);
    }
}

You can call this simply in your tests by:

$returnVal = PHPUnitUtil::callMethod(
                $this->object,
                '_nameOfProtectedMethod', 
                array($arg1, $arg2)
             );