How to integrate Dart into a Rails app

If you run pub build --mode=debug the build directory contains the application without symlinks. The Dart code should be retained when --mode=debug is used.

Here is some discussion going on about this topic too Dart and it's place in Rails Assets Pipeline

Can't perform a React state update on an unmounted component

Inspired by @ford04 answer I use this hook, which also takes callbacks for success, errors, finally and an abortFn:

export const useAsync = (
        asyncFn, 
        onSuccess = false, 
        onError = false, 
        onFinally = false, 
        abortFn = false
    ) => {

    useEffect(() => {
        let isMounted = true;
        const run = async () => {
            try{
                let data = await asyncFn()
                if (isMounted && onSuccess) onSuccess(data)
            } catch(error) {
                if (isMounted && onError) onSuccess(error)
            } finally {
                if (isMounted && onFinally) onFinally()
            }
        }
        run()
        return () => {
            if(abortFn) abortFn()
            isMounted = false
        };
    }, [asyncFn, onSuccess])
}

If the asyncFn is doing some kind of fetch from back-end it often makes sense to abort it when the component is unmounted (not always though, sometimes if ie. you're loading some data into a store you might as well just want to finish it even if component is unmounted)

How to handle "Uncaught (in promise) DOMException: play() failed because the user didn't interact with the document first." on Desktop with Chrome 66?

I had some issues playing on Android Phone. After few tries I found out that when Data Saver is on there is no auto play:

There is no autoplay if Data Saver mode is enabled. If Data Saver mode is enabled, autoplay is disabled in Media settings.

Source

Angular: Cannot Get /

Check if in index.html base is set

<head>
  <base href="/">
  ...
</head>

Why I can't access remote Jupyter Notebook server?

I got the same problem but none of workarounds above work for me. But if I setup a docker version jupyter notebook, with the same configuration, it works out for me.

For my stituation, it might be iptables rule issues. Sometimes you may just using ufw to allow all route to your server. But mine just iptables -F to clear all rule. Then check iptables -L -n to see if its works.

Problem fixed.

Are dictionaries ordered in Python 3.6+?

I wanted to add to the discussion above but don't have the reputation to comment.

Python 3.8 is not quite released yet, but it will even include the reversed() function on dictionaries (removing another difference from OrderedDict.

Dict and dictviews are now iterable in reversed insertion order using reversed(). (Contributed by Rémi Lapeyre in bpo-33462.) See what's new in python 3.8

I don't see any mention of the equality operator or other features of OrderedDict so they are still not entirely the same.

angular-cli server - how to proxy API requests to another server?

I'll explain what you need to know on the example below:

{
  "/folder/sub-folder/*": {
    "target": "http://localhost:1100",
    "secure": false,
    "pathRewrite": {
      "^/folder/sub-folder/": "/new-folder/"
    },
    "changeOrigin": true,
    "logLevel": "debug"
  }
}

/folder/sub-folder/*: path says: When I see this path inside my angular app (the path can be stored anywhere) I want to do something with it. The * character indicates that everything that follows the sub-folder will be included. For instance, if you have multiple fonts inside /folder/sub-folder/, the * will pick up all of them
"target": "http://localhost:1100" for the path above make target URL the host/source, therefore in the background we will have http://localhost:1100/folder/sub-folder/
"pathRewrite": { "^/folder/sub-folder/": "/new-folder/" }, Now let's say that you want to test your app locally, the url http://localhost:1100/folder/sub-folder/ may contain an invalid path: /folder/sub-folder/. You want to change that path to a correct one which is http://localhost:1100/new-folder/, therefore the pathRewrite will become useful. It will exclude the path in the app(left side) and include the newly written one (right side)
"secure": represents wether we are using http or https. If https is used in the target attribute then set secure attribute to true otherwise set it to false
"changeOrigin": option is only necessary if your host target is not the current environment, for example: localhost. If you want to change the host to www.something.com which would be the target in the proxy then set the changeOrigin attribute to "true":
"logLevel": attribute specifies wether the developer wants to display proxying on his terminal/cmd, hence he would use the "debug" value as shown in the image

In general, the proxy helps in developing the application locally. You set your file paths for production purpose and if you have all these files locally inside your project you may just use proxy to access them without changing the path dynamically in your app.

If it works, you should see something like this in your cmd/terminal.

How do I pass data to Angular routed components?

I think since we don't have $rootScope kind of thing in angular 2 as in angular 1.x. We can use angular 2 shared service/class while in ngOnDestroy pass data to service and after routing take the data from the service in ngOnInit function:

Here I am using DataService to share hero object:

import { Hero } from './hero';
export class DataService {
  public hero: Hero;
}

Pass object from first page component:

 ngOnDestroy() {
    this.dataService.hero = this.hero; 
 }

Take object from second page component:

 ngOnInit() {
    this.hero = this.dataService.hero; 
 }

Here is an example: plunker

XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header

"Get" request with appending headers transform to "Options" request. So Cors policy problems occur. You have to implement "Options" request to your server.

How do you deploy Angular apps?

With the Angular CLI it's easy. An example for Heroku:

Create a Heroku account and install the CLI
Move the angular-cli dep to the dependencies in package.json (so that it gets installed when you push to Heroku.
Add a postinstall script that will run ng build when the code gets pushed to Heroku. Also add a start command for a Node server that will be created in the following step. This will place the static files for the app in a dist directory on the server and start the app afterward.

"scripts": {
  // ...
  "start": "node server.js",
  "postinstall": "ng build --aot -prod"
}

Create an Express server to serve the app.

// server.js
const express = require('express');
const app = express();
// Run the app by serving the static files
// in the dist directory
app.use(express.static(__dirname + '/dist'));
// Start the app by listening on the default
// Heroku port
app.listen(process.env.PORT || 8080);

Create a Heroku remote and push to depoy the app.

heroku create
git add .
git commit -m "first deploy"
git push heroku master

Here's a quick writeup I did that has more detail, including how to force requests to use HTTPS and how to handle PathLocationStrategy :)

Delegation: EventEmitter or Observable in Angular

I found out another solution for this case without using Reactivex neither services. I actually love the rxjx API however I think it goes best when resolving an async and/or complex function. Using It in that way, Its pretty exceeded to me.

What I think you are looking for is for a broadcast. Just that. And I found out this solution:

<app>
  <app-nav (selectedTab)="onSelectedTab($event)"></app-nav>
       // This component bellow wants to know when a tab is selected
       // broadcast here is a property of app component
  <app-interested [broadcast]="broadcast"></app-interested>
</app>

 @Component class App {
   broadcast: EventEmitter<tab>;

   constructor() {
     this.broadcast = new EventEmitter<tab>();
   }

   onSelectedTab(tab) {
     this.broadcast.emit(tab)
   }    
 }

 @Component class AppInterestedComponent implements OnInit {
   broadcast: EventEmitter<Tab>();

   doSomethingWhenTab(tab){ 
      ...
    }     

   ngOnInit() {
     this.broadcast.subscribe((tab) => this.doSomethingWhenTab(tab))
   }
 }

This is a full working example: https://plnkr.co/edit/xGVuFBOpk2GP0pRBImsE

Webpack "OTS parsing error" loading fonts

I experienced the same problem, but for different reasons.

After Will Madden's solution didn't help, I tried every alternative fix I could find via the Intertubes - also to no avail. Exploring further, I just happened to open up one of the font files at issue. The original content of the file had somehow been overwritten by Webpack to include some kind of configuration info, likely from previous tinkering with the file-loader. I replaced the corrupted files with the originals, and voilà, the errors disappeared (for both Chrome and Firefox).

Get list of filenames in folder with Javascript

For client side files, you cannot get a list of files in a user's local directory.

If the user has provided uploaded files, you can access them via their input element.

<input type="file" name="client-file" id="get-files" multiple />


<script>
var inp = document.getElementById("get-files");
// Access and handle the files 

for (i = 0; i < inp.files.length; i++) {
    let file = inp.files[i];
    // do things with file
}
</script>

The service cannot accept control messages at this time

I forgot I had mine attached to Visual Studio debugger. Be sure to disconnect from there, and then wait a moment. Otherwise killing the process viewing the PID from the Worker Processes functionality of IIS manager will work too.

"Could not find acceptable representation" using spring-boot-starter-web

I had a similar error using spring/jhipster RESTful service (via Postman)

The endpoint was something like:

@RequestMapping(value = "/index-entries/{id}",
        method = RequestMethod.GET,
        produces = MediaType.APPLICATION_JSON_VALUE)
@Timed
public ResponseEntity<IndexEntry> getIndexEntry(@PathVariable Long id) {

I was attempting to call the restful endpoint via Postman with header Accept: text/plain but I needed to use Accept: application/json

How to convert entire dataframe to numeric while preserving decimals?

df2 <- data.frame(apply(df1, 2, function(x) as.numeric(as.character(x))))

java.net.SocketException: Connection reset by peer: socket write error When serving a file

This problem is usually caused by writing to a connection that had already been closed by the peer. In this case it could indicate that the user cancelled the download for example.

Serving static web resources in Spring Boot & Spring Security application

i had the same issue with my spring boot application, so I thought it will be nice if i will share with you guys my solution. I just simply configure the antMatchers to be suited to specific type of filles. In my case that was only js filles and js.map. Here is a code:

   @Configuration
   @EnableWebSecurity
   public class SecurityConfig extends WebSecurityConfigurerAdapter {

   @Override
   protected void configure(HttpSecurity http) throws Exception {
       http.authorizeRequests()
      .antMatchers("/index.html", "/", "/home", 
       "/login","/favicon.ico","/*.js","/*.js.map").permitAll()
      .anyRequest().authenticated().and().csrf().disable();
   }
  }

What is interesting. I find out that resources path like "resources/myStyle.css" in antMatcher didnt work for me at all. If you will have folder inside your resoruces folder just add it in antMatcher like "/myFolder/myFille.js"* and it should work just fine.

Spring Boot not serving static content

This solution works for me:

First, put a resources folder under webapp/WEB-INF, as follow structure

-- src
  -- main
    -- webapp
      -- WEB-INF
        -- resources
          -- css
          -- image
          -- js
          -- ...

Second, in spring config file

@Configuration
@EnableWebMvc
public class MvcConfig extends WebMvcConfigurerAdapter{

    @Bean
    public ViewResolver getViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".html");
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(
            DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resource/**").addResourceLocations("WEB-INF/resources/");
    }
}

Then, you can access your resource content, such as http://localhost:8080/resource/image/yourimage.jpg

Flask Download a File

I was also developing a similar application. I was also getting not found error even though the file was there. This solve my problem. I mention my download folder in 'static_folder':

app = Flask(__name__,static_folder='pdf')

My code for the download is as follows:

@app.route('/pdf/<path:filename>', methods=['GET', 'POST'])
def download(filename):    
    return send_from_directory(directory='pdf', filename=filename)

This is how I am calling my file from html.

<a class="label label-primary" href=/pdf/{{  post.hashVal }}.pdf target="_blank"  style="margin-right: 5px;">Download pdf </a>
<a class="label label-primary" href=/pdf/{{  post.hashVal }}.png target="_blank"  style="margin-right: 5px;">Download png </a>

PostgreSQL return result set as JSON array?

TL;DR

SELECT json_agg(t) FROM t

for a JSON array of objects, and

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )
FROM t

for a JSON object of arrays.

List of objects

This section describes how to generate a JSON array of objects, with each row being converted to a single object. The result looks like this:

[{"a":1,"b":"value1"},{"a":2,"b":"value2"},{"a":3,"b":"value3"}]

9.3 and up

The json_agg function produces this result out of the box. It automatically figures out how to convert its input into JSON and aggregates it into an array.

SELECT json_agg(t) FROM t

There is no jsonb (introduced in 9.4) version of json_agg. You can either aggregate the rows into an array and then convert them:

SELECT to_jsonb(array_agg(t)) FROM t

or combine json_agg with a cast:

SELECT json_agg(t)::jsonb FROM t

My testing suggests that aggregating them into an array first is a little faster. I suspect that this is because the cast has to parse the entire JSON result.

9.2

9.2 does not have the json_agg or to_json functions, so you need to use the older array_to_json:

SELECT array_to_json(array_agg(t)) FROM t

You can optionally include a row_to_json call in the query:

SELECT array_to_json(array_agg(row_to_json(t))) FROM t

This converts each row to a JSON object, aggregates the JSON objects as an array, and then converts the array to a JSON array.

I wasn't able to discern any significant performance difference between the two.

Object of lists

This section describes how to generate a JSON object, with each key being a column in the table and each value being an array of the values of the column. It's the result that looks like this:

{"a":[1,2,3], "b":["value1","value2","value3"]}

9.5 and up

We can leverage the json_build_object function:

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )
FROM t

You can also aggregate the columns, creating a single row, and then convert that into an object:

SELECT to_json(r)
FROM (
    SELECT
        json_agg(t.a) AS a,
        json_agg(t.b) AS b
    FROM t
) r

Note that aliasing the arrays is absolutely required to ensure that the object has the desired names.

Which one is clearer is a matter of opinion. If using the json_build_object function, I highly recommend putting one key/value pair on a line to improve readability.

You could also use array_agg in place of json_agg, but my testing indicates that json_agg is slightly faster.

There is no jsonb version of the json_build_object function. You can aggregate into a single row and convert:

SELECT to_jsonb(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

Unlike the other queries for this kind of result, array_agg seems to be a little faster when using to_jsonb. I suspect this is due to overhead parsing and validating the JSON result of json_agg.

Or you can use an explicit cast:

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )::jsonb
FROM t

The to_jsonb version allows you to avoid the cast and is faster, according to my testing; again, I suspect this is due to overhead of parsing and validating the result.

9.4 and 9.3

The json_build_object function was new to 9.5, so you have to aggregate and convert to an object in previous versions:

SELECT to_json(r)
FROM (
    SELECT
        json_agg(t.a) AS a,
        json_agg(t.b) AS b
    FROM t
) r

SELECT to_jsonb(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

depending on whether you want json or jsonb.

(9.3 does not have jsonb.)

9.2

In 9.2, not even to_json exists. You must use row_to_json:

SELECT row_to_json(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

Documentation

Find the documentation for the JSON functions in JSON functions.

json_agg is on the aggregate functions page.

Design

If performance is important, ensure you benchmark your queries against your own schema and data, rather than trust my testing.

Whether it's a good design or not really depends on your specific application. In terms of maintainability, I don't see any particular problem. It simplifies your app code and means there's less to maintain in that portion of the app. If PG can give you exactly the result you need out of the box, the only reason I can think of to not use it would be performance considerations. Don't reinvent the wheel and all.

Nulls

Aggregate functions typically give back NULL when they operate over zero rows. If this is a possibility, you might want to use COALESCE to avoid them. A couple of examples:

SELECT COALESCE(json_agg(t), '[]'::json) FROM t

SELECT to_jsonb(COALESCE(array_agg(t), ARRAY[]::t[])) FROM t

_{Credit to Hannes Landeholm for pointing this out}

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyController':

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyController'

Make sure that you have added ojdbc14.jar into your library.

For oracle 11g, usie ojdbc6.jar.

How to use the 'main' parameter in package.json?

To answer your first question, the way you load a module is depending on the module entry point and the main parameter of the package.json.

Let's say you have the following file structure:

my-npm-module
|-- lib
|   |-- module.js
|-- package.json

Without main parameter in the package.json, you have to load the module by giving the module entry point: require('my-npm-module/lib/module.js').

If you set the package.json main parameter as follows "main": "lib/module.js", you will be able to load the module this way: require('my-npm-module').

json: cannot unmarshal object into Go value of type

Determining of root cause is not an issue since Go 1.8; field name now is shown in the error message:

json: cannot unmarshal object into Go struct field Comment.author of type string

PUT and POST getting 405 Method Not Allowed Error for Restful Web Services

I'm not sure if I am correct, but from the request header that you post:

Request headers

Accept: Application/json

Origin: chrome-extension://hgmloofddffdnphfgcellkdfbfbjeloo

User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.76 Safari/537.36

Content-Type: application/x-www-form-urlencoded

Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8

it seems like you didn't config your request body to JSON type.

Add x and y labels to a pandas plot

You can use do it like this:

import matplotlib.pyplot as plt 
import pandas as pd

plt.figure()
values = [[1, 2], [2, 5]]
df2 = pd.DataFrame(values, columns=['Type A', 'Type B'], 
                   index=['Index 1', 'Index 2'])
df2.plot(lw=2, colormap='jet', marker='.', markersize=10,
         title='Video streaming dropout by category')
plt.xlabel('xlabel')
plt.ylabel('ylabel')
plt.show()

Obviously you have to replace the strings 'xlabel' and 'ylabel' with what you want them to be.

Launching Spring application Address already in use

In my case, Oracle TNS Service was using port 8080, found that using running the command "netstat - anob" as an administrator. Simply used Shutdown Database from the Windows start menu to stop that service and was able to start the SpringBoot app without any issue.

Also if you cannot find out which app is using the 8080 port and just want to run the SprintBoot app, you can click on Run As... and in the VM arguments enter: -Dserver.port=0 (this will pick any random available port) or you can be specific like: -Dserver.port=8081

Hope it helps.

Cloudfront custom-origin distribution returns 502 "ERROR The request could not be satisfied." for some URLs

Fixed this issue by concatenating my certificates to generate a valid certificate chain (using GoDaddy Standard SSL + Nginx).

http://nginx.org/en/docs/http/configuring_https_servers.html#chains

To generate the chain:

cat 123456789.crt gd_bundle-g2-g1.crt > my.domain.com.chained.crt

Then:

ssl_certificate /etc/nginx/ssl/my.domain.com.chained.crt;
ssl_certificate_key /etc/nginx/ssl/my.domain.com.key;

Hope it helps!

How to serve static files in Flask

If you are just trying to open a file, you could use app.open_resource(). So reading a file would look something like

with app.open_resource('/static/path/yourfile'):
      #code to read the file and do something

How do I get Flask to run on port 80?

I had to set FLASK_RUN_PORT in my environment to the specified port number. Next time you start your app, Flask will load that environment variable with the port number you selected.

How do you decrease navbar height in Bootstrap 3?

If you have only one nav and you want to change it, you should change your variables.less: @navbar-height (somewhere near line 265, I can't recall how many lines I added to mine).

This is referenced by the mixin .navbar-vertical-align, which is used for example to position the "toggle" element, anything with .navbar-form, .navbar-btn, and .navbar-text.

If you have two navbars and want them to be different heights, Minder Saini's answer may work well enough, when qualified further by an , e.g., #topnav.navbar but should be tested across multiple device widths.

Map over object preserving keys

A mix fix for the underscore map bug :P

_.mixin({ 
    mapobj : function( obj, iteratee, context ) {
        if (obj == null) return [];
        iteratee = _.iteratee(iteratee, context);
        var keys = obj.length !== +obj.length && _.keys(obj),
            length = (keys || obj).length,
            results = {},
            currentKey;
        for (var index = 0; index < length; index++) {
          currentKey = keys ? keys[index] : index;
          results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
        }
        if ( _.isObject( obj ) ) {
            return _.object( results ) ;
        } 
        return results;
    }
});

A simple workaround that keeps the right key and return as object It is still used the same way as i guest you could used this function to override the bugy _.map function

or simply as me used it as a mixin

_.mapobj ( options , function( val, key, list )

AngularJS: how to enable $locationProvider.html5Mode with deeplinking

This was the best solution I found after more time than I care to admit. Basically, add target="_self" to each link that you need to insure a page reload.

http://blog.panjiesw.com/posts/2013/09/angularjs-normal-links-with-html5mode/

Difference between no-cache and must-revalidate

max-age=0, must-revalidate and no-cache aren't exactly identical. With must-revalidate, if the server doesn't respond to a revalidation request, the browser/proxy is supposed to return a 504 error. With no-cache, it would just show the cached content, which would be probably preferred by the user (better to have something stale than nothing at all). This is why must-revalidate is intended for critical transactions only.

How can I make this try_files directive work?

a very common try_files line which can be applied on your condition is

location / {
    try_files $uri $uri/ /test/index.html;
}

you probably understand the first part, location / matches all locations, unless it's matched by a more specific location, like location /test for example

The second part ( the try_files ) means when you receive a URI that's matched by this block try $uri first, for example http://example.com/images/image.jpg nginx will try to check if there's a file inside /images called image.jpg if found it will serve it first.

Second condition is $uri/ which means if you didn't find the first condition $uri try the URI as a directory, for example http://example.com/images/, ngixn will first check if a file called images exists then it wont find it, then goes to second check $uri/ and see if there's a directory called images exists then it will try serving it.

Side note: if you don't have autoindex on you'll probably get a 403 forbidden error, because directory listing is forbidden by default.

EDIT: I forgot to mention that if you have index defined, nginx will try to check if the index exists inside this folder before trying directory listing.

Third condition /test/index.html is considered a fall back option, (you need to use at least 2 options, one and a fall back), you can use as much as you can (never read of a constriction before), nginx will look for the file index.html inside the folder test and serve it if it exists.

If the third condition fails too, then nginx will serve the 404 error page.

Also there's something called named locations, like this

location @error {
}

You can call it with try_files like this

try_files $uri $uri/ @error;

TIP: If you only have 1 condition you want to serve, like for example inside folder images you only want to either serve the image or go to 404 error, you can write a line like this

location /images {
    try_files $uri =404;
}

which means either serve the file or serve a 404 error, you can't use only $uri by it self without =404 because you need to have a fallback option.
You can also choose which ever error code you want, like for example:

location /images {
    try_files $uri =403;
}

This will show a forbidden error if the image doesn't exist, or if you use 500 it will show server error, etc ..

Moving Git repository content to another repository preserving history

There are a lot of complicated answers, here; however, if you are not concerned with branch preservation, all you need to do is reset the remote origin, set the upstream, and push.

This worked to preserve all the commit history for me.

cd <location of local repo.>
git remote set-url origin <url>
git push -u origin master

Differences between hard real-time, soft real-time, and firm real-time?

To define "soft real-time," it is easiest to compare it with "hard real-time." Below we will see that the term "firm real-time" constitutes a misunderstanding about "soft real-time."

Speaking casually, most people implicitly have an informal mental model that considers information or an event as being "real-time"

• if, or to the extent that, it is manifest to them with a delay (latency) that can be related to its perceived currency

• i.e., in a time frame that the information or event has acceptably satisfactory value to them.

There are numerous different ad hoc definitions of "hard real-time," but in that mental model, hard real-time is represented by the "if" term. Specifically, assuming that real-time actions (such as tasks) have completion deadlines, acceptably satisfactory value of the event that all tasks complete is limited to the special case that all tasks meet their deadlines.

Hard real-time systems make the very strong assumptions that everything about the application and system and environment is static and known a' priori—e.g., which tasks, that they are periodic, their arrival times, their periods, their deadlines, that they won’t have resource conflicts, and overall the time evolution of the system. In an aircraft flight control system or automotive braking system and many other cases those assumptions can usually be satisfied so that all the deadlines will be met.

This mental model is deliberately and very usefully general enough to encompass both hard and soft real-time--soft is accommodated by the "to the extent that" phrase. For example, suppose that the task completions event has suboptimal but acceptable value if

no more than 10% of the tasks miss their deadlines
or no task is more than 20% tardy
or the average tardiness of all tasks is no more than 15%
or the maximum tardiness among all tasks is less than 10%

These are all common examples of soft real-time cases in a great many applications.

Consider the single-task application of picking your child up after school. That probably does not have an actual deadline, instead there is some value to you and your child based on when that event takes place. Too early wastes resources (such as your time) and too late has some negative value because your child might be left alone and potentially in harm's way (or at least inconvenienced).

Unlike the static hard real-time special case, soft real-time makes only the minimum necessary application-specific assumptions about the tasks and system, and uncertainties are expected. To pick up your child, you have to drive to the school, and the time to do that is dynamic depending on weather, traffic conditions, etc. You might be tempted to over-provision your system (i.e., allow what you hope is the worst case driving time) but again this is wasting resources (your time, and occupying the family vehicle, possibly denying use by other family members).

That example may not seem to be costly in terms of wasted resources, but consider other examples. All military combat systems are soft real-time. For example, consider performing an aircraft attack on a hostile ground vehicle using a missile guided with updates to it as the target maneuvers. The maximum satisfaction for completing the course update tasks is achieved by a direct destructive strike on the target. But an attempt to over-provision resources to make certain of this outcome is usually far too expensive and may even be impossible. In this case, you may be less but sufficiently satisfied if the missile strikes close enough to the target to disable it.

Obviously combat scenarios have a great many possible dynamic uncertainties that must be accommodated by the resource management. Soft real-time systems are also very common in many civilian systems, such as industrial automation, although obviously military ones are the most dangerous and urgent ones to achieve acceptably satisfactory value in.

The keystone of real-time systems is "predictability." The hard real-time case is interested in only one special case of predictability--i.e., that the tasks will all meet their deadlines and the maximum possible value will be achieved by that event. That special case is named "deterministic."

There is a spectrum of predictability. Deterministic (determinism) is one end-point (maximum predictability) on the predictability spectrum; the other end-point is minimum predictability (maximum non-determinism). The spectrum's metric and end-points have to be interpreted in terms of a chosen predictability model; everything between those two end-points is degrees of unpredictability (= degrees of non-determinism).

Most real-time systems (namely, soft ones) have non-deterministic predictability, for example, of the tasks' completions times and hence the values gained from those events.

In general (in theory), predictability, and hence acceptably satisfactory value, can be made as close to the deterministic end-point as necessary--but at a price which may be physically impossible or excessively expensive (as in combat or perhaps even in picking up your child from school).

Soft real-time requires an application-specific choice of a probability model (not the common frequentist model) and hence predictability model for reasoning about event latencies and resulting values.

Referring back to the above list of events that provide acceptable value, now we can add non-deterministic cases, such as

the probability that no task will miss its deadline by more than 5% is greater than 0.87. (Note the number of scheduling criteria expressed in there.)

In a missile defense application, given the fact that in combat the offense always has the advantage over the defense, which of these two real-time computing scenarios would you prefer:

because the perfect destruction of all the hostile missiles is very unlikely or impossible, assign your defensive resources to maximize the probability that as many of the most threatening (e.g., based on their targets) hostile missiles will be successfully intercepted (close interception counts because it can move the hostile missile off-course);
complain that this is not a real-time computing problem because it is dynamic instead of static, and traditional real-time concepts and techniques do not apply, and it sounds more difficult than static hard real-time, so you are not interested in it.

Despite the various misunderstandings about soft real-time in the real-time computing community, soft real-time is very general and powerful, albeit potentially complex compared with hard real-time. Soft real-time systems as summarized here have a lengthy successful history of use outside the real-time computing community.

To directly answer the OP question:

A hard real-time system can provide deterministic guarantees—most commonly that all tasks will meet their deadlines, interrupt or system call response time will always be less than x, etc.—IF AND ONLY IF very strong assumptions are made and are correct that everything that matters is static and known a' priori (in general, such guarantees for hard real-time systems are an open research problem except for rather simple cases)

A soft real-time system does not make deterministic guarantees, it is intended to provide the best possible analytically specified and accomplished probabilistic timeliness and predictability of timeliness that are feasible under the current dynamic circumstances, according to application-specific criteria.

Obviously hard real-time is a simple special case of soft real-time. Obviously soft real-time's analytical non-deterministic assurances can be very complex to provide, but are mandatory in the most common real-time cases (including the most dangerous safety-critical ones such as combat) since most real-time cases are dynamic not static.

"Firm real-time" is an ill-defined special case of "soft real-time." There is no need for this term if the term "soft real-time" is understood and used properly.

I have a more detailed much more precise discussion of real-time, hard real-time, soft real-time, predictability, determinism, and related topics on my web site real-time.org.

Can local storage ever be considered secure?

Well, the basic premise here is: no, it is not secure yet.

Basically, you can't run crypto in JavaScript: JavaScript Crypto Considered Harmful.

The problem is that you can't reliably get the crypto code into the browser, and even if you could, JS isn't designed to let you run it securely. So until browsers have a cryptographic container (which Encrypted Media Extensions provide, but are being rallied against for their DRM purposes), it will not be possible to do securely.

As far as a "Better way", there isn't one right now. Your only alternative is to store the data in plain text, and hope for the best. Or don't store the information at all. Either way.

Either that, or if you need that sort of security, and you need local storage, create a custom application...

Git copy file preserving history

Unlike subversion, git does not have a per-file history. If you look at the commit data structure, it only points to the previous commits and the new tree object for this commit. No explicit information is stored in the commit object which files are changed by the commit; nor the nature of these changes.

The tools to inspect changes can detect renames based on heuristics. E.g. "git diff" has the option -M that turns on rename detection. So in case of a rename, "git diff" might show you that one file has been deleted and another one created, while "git diff -M" will actually detect the move and display the change accordingly (see "man git diff" for details).

So in git this is not a matter of how you commit your changes but how you look at the committed changes later.

Convert pandas timezone-aware DateTimeIndex to naive timestamp, but in certain timezone

Because I always struggle to remember, a quick summary of what each of these do:

>>> pd.Timestamp.now()  # naive local time
Timestamp('2019-10-07 10:30:19.428748')

>>> pd.Timestamp.utcnow()  # tz aware UTC
Timestamp('2019-10-07 08:30:19.428748+0000', tz='UTC')

>>> pd.Timestamp.now(tz='Europe/Brussels')  # tz aware local time
Timestamp('2019-10-07 10:30:19.428748+0200', tz='Europe/Brussels')

>>> pd.Timestamp.now(tz='Europe/Brussels').tz_localize(None)  # naive local time
Timestamp('2019-10-07 10:30:19.428748')

>>> pd.Timestamp.now(tz='Europe/Brussels').tz_convert(None)  # naive UTC
Timestamp('2019-10-07 08:30:19.428748')

>>> pd.Timestamp.utcnow().tz_localize(None)  # naive UTC
Timestamp('2019-10-07 08:30:19.428748')

>>> pd.Timestamp.utcnow().tz_convert(None)  # naive UTC
Timestamp('2019-10-07 08:30:19.428748')

S3 Static Website Hosting Route All Paths to Index.html

I was looking for an answer to this myself. S3 appears to only support redirects, you can't just rewrite the URL and silently return a different resource. I'm considering using my build script to simply make copies of my index.html in all of the required path locations. Maybe that will work for you too.

Can I delete a git commit but keep the changes?

It's as simple as this:

git reset HEAD^

Note: some shells treat ^ as a special character (for example some Windows shells or ZSH with globbing enabled), so you may have to quote "HEAD^" in those cases.

git reset without a --hard or --soft moves your HEAD to point to the specified commit, without changing any files. HEAD^ refers to the (first) parent commit of your current commit, which in your case is the commit before the temporary one.

Note that another option is to carry on as normal, and then at the next commit point instead run:

git commit --amend [-m … etc]

which will instead edit the most recent commit, having the same effect as above.

Note that this (as with nearly every git answer) can cause problems if you've already pushed the bad commit to a place where someone else may have pulled it from. Try to avoid that

Can I serve multiple clients using just Flask app.run() as standalone?

Tips from 2020:

From Flask 1.0, it defaults to enable multiple threads (source), you don't need to do anything, just upgrade it with:

$ pip install -U flask

If you are using flask run instead of app.run() with older versions, you can control the threaded behavior with a command option (--with-threads/--without-threads):

$ flask run --with-threads

It's same as app.run(threaded=True)

How to capture no file for fs.readFileSync()?

You have to catch the error and then check what type of error it is.

try {
  var data = fs.readFileSync(...)
} catch (err) {
  // If the type is not what you want, then just throw the error again.
  if (err.code !== 'ENOENT') throw err;

  // Handle a file-not-found error
}

making matplotlib scatter plots from dataframes in Python's pandas

I will recommend to use an alternative method using seaborn which more powerful tool for data plotting. You can use seaborn scatterplot and define colum 3 as hue and size.

Working code:

import pandas as pd
import seaborn as sns
import numpy as np

#creating sample data 
sample_data={'col_name_1':np.random.rand(20),
      'col_name_2': np.random.rand(20),'col_name_3': np.arange(20)*100}
df= pd.DataFrame(sample_data)
sns.scatterplot(x="col_name_1", y="col_name_2", data=df, hue="col_name_3",size="col_name_3")

How to force addition instead of concatenation in javascript

Your code concatenates three strings, then converts the result to a number.

You need to convert each variable to a number by calling parseFloat() around each one.

total = parseFloat(myInt1) + parseFloat(myInt2) + parseFloat(myInt3);

Correct MIME Type for favicon.ico?

When you're serving an .ico file to be used as a favicon, it doesn't matter. All major browsers recognize both mime types correctly. So you could put:

<!-- IE -->
<link rel="shortcut icon" type="image/x-icon" href="favicon.ico" />
<!-- other browsers -->
<link rel="icon" type="image/x-icon" href="favicon.ico" />

or the same with image/vnd.microsoft.icon, and it will work with all browsers.

Note: There is no IANA specification for the MIME-type image/x-icon, so it does appear that it is a little more unofficial than image/vnd.microsoft.icon.

The only case in which there is a difference is if you were trying to use an .ico file in an <img> tag (which is pretty unusual). Based on previous testing, some browsers would only display .ico files as images when they were served with the MIME-type image/x-icon. More recent tests show: Chromium, Firefox and Edge are fine with both content types, IE11 is not. If you can, just avoid using ico files as images, use png.

HAProxy redirecting http to https (ssl)

Like Jay Taylor said, HAProxy 1.5-dev has the redirect scheme configuration directive, which accomplishes exactly what you need.

However, if you are unable to use 1.5, and if you're up for compiling HAProxy from source, I backported the redirect scheme functionality so it works in 1.4. You can get the patch here: http://marc.info/?l=haproxy&m=138456233430692&w=2

CORS Access-Control-Allow-Headers wildcard being ignored?

Those CORS headers do not support * as value, the only way is to replace * with this:

Accept, Accept-CH, Accept-Charset, Accept-Datetime, Accept-Encoding, Accept-Ext, Accept-Features, Accept-Language, Accept-Params, Accept-Ranges, Access-Control-Allow-Credentials, Access-Control-Allow-Headers, Access-Control-Allow-Methods, Access-Control-Allow-Origin, Access-Control-Expose-Headers, Access-Control-Max-Age, Access-Control-Request-Headers, Access-Control-Request-Method, Age, Allow, Alternates, Authentication-Info, Authorization, C-Ext, C-Man, C-Opt, C-PEP, C-PEP-Info, CONNECT, Cache-Control, Compliance, Connection, Content-Base, Content-Disposition, Content-Encoding, Content-ID, Content-Language, Content-Length, Content-Location, Content-MD5, Content-Range, Content-Script-Type, Content-Security-Policy, Content-Style-Type, Content-Transfer-Encoding, Content-Type, Content-Version, Cookie, Cost, DAV, DELETE, DNT, DPR, Date, Default-Style, Delta-Base, Depth, Derived-From, Destination, Differential-ID, Digest, ETag, Expect, Expires, Ext, From, GET, GetProfile, HEAD, HTTP-date, Host, IM, If, If-Match, If-Modified-Since, If-None-Match, If-Range, If-Unmodified-Since, Keep-Alive, Label, Last-Event-ID, Last-Modified, Link, Location, Lock-Token, MIME-Version, Man, Max-Forwards, Media-Range, Message-ID, Meter, Negotiate, Non-Compliance, OPTION, OPTIONS, OWS, Opt, Optional, Ordering-Type, Origin, Overwrite, P3P, PEP, PICS-Label, POST, PUT, Pep-Info, Permanent, Position, Pragma, ProfileObject, Protocol, Protocol-Query, Protocol-Request, Proxy-Authenticate, Proxy-Authentication-Info, Proxy-Authorization, Proxy-Features, Proxy-Instruction, Public, RWS, Range, Referer, Refresh, Resolution-Hint, Resolver-Location, Retry-After, Safe, Sec-Websocket-Extensions, Sec-Websocket-Key, Sec-Websocket-Origin, Sec-Websocket-Protocol, Sec-Websocket-Version, Security-Scheme, Server, Set-Cookie, Set-Cookie2, SetProfile, SoapAction, Status, Status-URI, Strict-Transport-Security, SubOK, Subst, Surrogate-Capability, Surrogate-Control, TCN, TE, TRACE, Timeout, Title, Trailer, Transfer-Encoding, UA-Color, UA-Media, UA-Pixels, UA-Resolution, UA-Windowpixels, URI, Upgrade, User-Agent, Variant-Vary, Vary, Version, Via, Viewport-Width, WWW-Authenticate, Want-Digest, Warning, Width, X-Content-Duration, X-Content-Security-Policy, X-Content-Type-Options, X-CustomHeader, X-DNSPrefetch-Control, X-Forwarded-For, X-Forwarded-Port, X-Forwarded-Proto, X-Frame-Options, X-Modified, X-OTHER, X-PING, X-PINGOTHER, X-Powered-By, X-Requested-With

`.htaccess` Example (CORS Included):

<IfModule mod_headers.c>
  Header unset Connection
  Header unset Time-Zone
  Header unset Keep-Alive
  Header unset Access-Control-Allow-Origin
  Header unset Access-Control-Allow-Headers
  Header unset Access-Control-Expose-Headers
  Header unset Access-Control-Allow-Methods
  Header unset Access-Control-Allow-Credentials

  Header set   Connection                         keep-alive
  Header set   Time-Zone                          "Asia/Jerusalem"
  Header set   Keep-Alive                         timeout=100,max=500
  Header set   Access-Control-Allow-Origin        "*"
  Header set   Access-Control-Allow-Headers       "Accept, Accept-CH, Accept-Charset, Accept-Datetime, Accept-Encoding, Accept-Ext, Accept-Features, Accept-Language, Accept-Params, Accept-Ranges, Access-Control-Allow-Credentials, Access-Control-Allow-Headers, Access-Control-Allow-Methods, Access-Control-Allow-Origin, Access-Control-Expose-Headers, Access-Control-Max-Age, Access-Control-Request-Headers, Access-Control-Request-Method, Age, Allow, Alternates, Authentication-Info, Authorization, C-Ext, C-Man, C-Opt, C-PEP, C-PEP-Info, CONNECT, Cache-Control, Compliance, Connection, Content-Base, Content-Disposition, Content-Encoding, Content-ID, Content-Language, Content-Length, Content-Location, Content-MD5, Content-Range, Content-Script-Type, Content-Security-Policy, Content-Style-Type, Content-Transfer-Encoding, Content-Type, Content-Version, Cookie, Cost, DAV, DELETE, DNT, DPR, Date, Default-Style, Delta-Base, Depth, Derived-From, Destination, Differential-ID, Digest, ETag, Expect, Expires, Ext, From, GET, GetProfile, HEAD, HTTP-date, Host, IM, If, If-Match, If-Modified-Since, If-None-Match, If-Range, If-Unmodified-Since, Keep-Alive, Label, Last-Event-ID, Last-Modified, Link, Location, Lock-Token, MIME-Version, Man, Max-Forwards, Media-Range, Message-ID, Meter, Negotiate, Non-Compliance, OPTION, OPTIONS, OWS, Opt, Optional, Ordering-Type, Origin, Overwrite, P3P, PEP, PICS-Label, POST, PUT, Pep-Info, Permanent, Position, Pragma, ProfileObject, Protocol, Protocol-Query, Protocol-Request, Proxy-Authenticate, Proxy-Authentication-Info, Proxy-Authorization, Proxy-Features, Proxy-Instruction, Public, RWS, Range, Referer, Refresh, Resolution-Hint, Resolver-Location, Retry-After, Safe, Sec-Websocket-Extensions, Sec-Websocket-Key, Sec-Websocket-Origin, Sec-Websocket-Protocol, Sec-Websocket-Version, Security-Scheme, Server, Set-Cookie, Set-Cookie2, SetProfile, SoapAction, Status, Status-URI, Strict-Transport-Security, SubOK, Subst, Surrogate-Capability, Surrogate-Control, TCN, TE, TRACE, Timeout, Title, Trailer, Transfer-Encoding, UA-Color, UA-Media, UA-Pixels, UA-Resolution, UA-Windowpixels, URI, Upgrade, User-Agent, Variant-Vary, Vary, Version, Via, Viewport-Width, WWW-Authenticate, Want-Digest, Warning, Width, X-Content-Duration, X-Content-Security-Policy, X-Content-Type-Options, X-CustomHeader, X-DNSPrefetch-Control, X-Forwarded-For, X-Forwarded-Port, X-Forwarded-Proto, X-Frame-Options, X-Modified, X-OTHER, X-PING, X-PINGOTHER, X-Powered-By, X-Requested-With"
  Header set   Access-Control-Expose-Headers      "Accept, Accept-CH, Accept-Charset, Accept-Datetime, Accept-Encoding, Accept-Ext, Accept-Features, Accept-Language, Accept-Params, Accept-Ranges, Access-Control-Allow-Credentials, Access-Control-Allow-Headers, Access-Control-Allow-Methods, Access-Control-Allow-Origin, Access-Control-Expose-Headers, Access-Control-Max-Age, Access-Control-Request-Headers, Access-Control-Request-Method, Age, Allow, Alternates, Authentication-Info, Authorization, C-Ext, C-Man, C-Opt, C-PEP, C-PEP-Info, CONNECT, Cache-Control, Compliance, Connection, Content-Base, Content-Disposition, Content-Encoding, Content-ID, Content-Language, Content-Length, Content-Location, Content-MD5, Content-Range, Content-Script-Type, Content-Security-Policy, Content-Style-Type, Content-Transfer-Encoding, Content-Type, Content-Version, Cookie, Cost, DAV, DELETE, DNT, DPR, Date, Default-Style, Delta-Base, Depth, Derived-From, Destination, Differential-ID, Digest, ETag, Expect, Expires, Ext, From, GET, GetProfile, HEAD, HTTP-date, Host, IM, If, If-Match, If-Modified-Since, If-None-Match, If-Range, If-Unmodified-Since, Keep-Alive, Label, Last-Event-ID, Last-Modified, Link, Location, Lock-Token, MIME-Version, Man, Max-Forwards, Media-Range, Message-ID, Meter, Negotiate, Non-Compliance, OPTION, OPTIONS, OWS, Opt, Optional, Ordering-Type, Origin, Overwrite, P3P, PEP, PICS-Label, POST, PUT, Pep-Info, Permanent, Position, Pragma, ProfileObject, Protocol, Protocol-Query, Protocol-Request, Proxy-Authenticate, Proxy-Authentication-Info, Proxy-Authorization, Proxy-Features, Proxy-Instruction, Public, RWS, Range, Referer, Refresh, Resolution-Hint, Resolver-Location, Retry-After, Safe, Sec-Websocket-Extensions, Sec-Websocket-Key, Sec-Websocket-Origin, Sec-Websocket-Protocol, Sec-Websocket-Version, Security-Scheme, Server, Set-Cookie, Set-Cookie2, SetProfile, SoapAction, Status, Status-URI, Strict-Transport-Security, SubOK, Subst, Surrogate-Capability, Surrogate-Control, TCN, TE, TRACE, Timeout, Title, Trailer, Transfer-Encoding, UA-Color, UA-Media, UA-Pixels, UA-Resolution, UA-Windowpixels, URI, Upgrade, User-Agent, Variant-Vary, Vary, Version, Via, Viewport-Width, WWW-Authenticate, Want-Digest, Warning, Width, X-Content-Duration, X-Content-Security-Policy, X-Content-Type-Options, X-CustomHeader, X-DNSPrefetch-Control, X-Forwarded-For, X-Forwarded-Port, X-Forwarded-Proto, X-Frame-Options, X-Modified, X-OTHER, X-PING, X-PINGOTHER, X-Powered-By, X-Requested-With"
  Header set   Access-Control-Allow-Methods       "CONNECT, DEBUG, DELETE, DONE, GET, HEAD, HTTP, HTTP/0.9, HTTP/1.0, HTTP/1.1, HTTP/2, OPTIONS, ORIGIN, ORIGINS, PATCH, POST, PUT, QUIC, REST, SESSION, SHOULD, SPDY, TRACE, TRACK"
  Header set   Access-Control-Allow-Credentials   "true"

  Header set DNT "0"
  Header set Accept-Ranges "bytes"
  Header set Vary "Accept-Encoding"
  Header set X-UA-Compatible "IE=edge,chrome=1"
  Header set X-Frame-Options "SAMEORIGIN"
  Header set X-Content-Type-Options "nosniff"
  Header set X-Xss-Protection "1; mode=block"
</IfModule>

F.A.Q:

Why Access-Control-Allow-Headers, Access-Control-Expose-Headers, Access-Control-Allow-Methods values are super long?

Those do not support the * syntax, so I've collected the most common (and exotic) headers from around the web, in various formats #1 #2 #3 _{(and I will update the list from time to time)}
Why do you use Header unset ______ syntax?

GoDaddy servers (which my website is hosted on..) have a weird bug where if the headers are already set, the previous value will join the existing one.. (instead of replacing it) this way I "pre-clean" existing values _{(really just a a quick && dirty solution)}
Is it safe for me to use 'as-is'?

Well.. mostly the answer would be YES since the .htaccess is limiting the headers to the scripts (PHP, HTML, ...) and resources (.JPG, .JS, .CSS) served from the following "folder"-location. You optionally might want to remove the Access-Control-Allow-Methods lines. _{Also Connection, Time-Zone, Keep-Alive and DNT, Accept-Ranges, Vary, X-UA-Compatible, X-Frame-Options, X-Content-Type-Options and X-Xss-Protection are just a suggestion I'm using for my online-service.. feel free to remove those too...}

_{taken from my comment above}

Where can I find the Tomcat 7 installation folder on Linux AMI in Elastic Beanstalk?

As of October 3, 2012, a new "Elastic Beanstalk for Java with Apache Tomcat 7" Linux x64 AMI deployed with the Sample Application has the install here:

/etc/tomcat7/

The /etc/tomcat7/tomcat7.conf file has the following settings:

# Where your java installation lives
JAVA_HOME="/usr/lib/jvm/jre"

# Where your tomcat installation lives
CATALINA_BASE="/usr/share/tomcat7"
CATALINA_HOME="/usr/share/tomcat7"
JASPER_HOME="/usr/share/tomcat7"
CATALINA_TMPDIR="/var/cache/tomcat7/temp"

Copying the cell value preserving the formatting from one cell to another in excel using VBA

I prefer to avoid using select

     With sheets("sheetname").range("I10") 
          .PasteSpecial Paste:=xlPasteValues, _
                  Operation:=xlNone, _
                  SkipBlanks:=False, _
                  Transpose:=False
          .PasteSpecial Paste:=xlPasteFormats, _
                  Operation:=xlNone, _
                  SkipBlanks:=False, _
                  Transpose:=False
          .font.color = sheets("sheetname").range("F10").font.color
      End With
      sheets("sheetname").range("I10:J10").merge

How to set max width of an image in CSS

Try this

 div#ImageContainer { width: 600px; }
 #ImageContainer img{ max-width: 600px}

trace a particular IP and port

you can use tcpdump on the server to check if the client even reaches the server.

  tcpdump -i any tcp port 9100

also make sure your firewall is not blocking incoming connections.

EDIT: you can also write the dump into a file and view it with wireshark on your client if you don't want to read it on the console.

2nd Edit: you can check if you can reach the port via

 nc ip 9100 -z -v

from your local PC.

How many concurrent requests does a single Flask process receive?

When running the development server - which is what you get by running app.run(), you get a single synchronous process, which means at most 1 request is being processed at a time.

By sticking Gunicorn in front of it in its default configuration and simply increasing the number of --workers, what you get is essentially a number of processes (managed by Gunicorn) that each behave like the app.run() development server. 4 workers == 4 concurrent requests. This is because Gunicorn uses its included sync worker type by default.

It is important to note that Gunicorn also includes asynchronous workers, namely eventlet and gevent (and also tornado, but that's best used with the Tornado framework, it seems). By specifying one of these async workers with the --worker-class flag, what you get is Gunicorn managing a number of async processes, each of which managing its own concurrency. These processes don't use threads, but instead coroutines. Basically, within each process, still only 1 thing can be happening at a time (1 thread), but objects can be 'paused' when they are waiting on external processes to finish (think database queries or waiting on network I/O).

This means, if you're using one of Gunicorn's async workers, each worker can handle many more than a single request at a time. Just how many workers is best depends on the nature of your app, its environment, the hardware it runs on, etc. More details can be found on Gunicorn's design page and notes on how gevent works on its intro page.

Error message "Forbidden You don't have permission to access / on this server"

On Ubuntu 14.04 using Apache 2.4, I did the following:

Add the following in the file, apache2.conf (under /etc/apache2):

<Directory /home/rocky/code/documentroot/>
  Options Indexes FollowSymLinks
  AllowOverride None
  Require all granted
</Directory>

and reload the server:

sudo service apache2 reload

Edit: This also works on OS X Yosemite with Apache 2.4. The all-important line is

Require all granted

Nginx -- static file serving confusion with root & alias

Just a quick addendum to @good_computer's very helpful answer, I wanted to replace to root of the URL with a folder, but only if it matched a subfolder containing static files (which I wanted to retain as part of the path).

For example if file requested is in /app/js or /app/css, look in /app/location/public/[that folder].

I got this to work using a regex.

 location ~ ^/app/((images/|stylesheets/|javascripts/).*)$ {
     alias /home/user/sites/app/public/$1;
     access_log off;
     expires max;
 }

Error creating bean with name

I think it comes from this line in your XML file:

<context:component-scan base-package="org.assessme.com.controller." />

Replace it by:

<context:component-scan base-package="org.assessme.com." />

It is because your Autowired service is not scanned by Spring since it is not in the right package.

How to send data in request body with a GET when using jQuery $.ajax()

Just in case somebody ist still coming along this question:

There is a body query object in any request. You do not need to parse it yourself.

E.g. if you want to send an accessToken from a client with GET, you could do it like this:

_x000D_

const request = require('superagent');_x000D_
_x000D_
request.get(`http://localhost:3000/download?accessToken=${accessToken}`).end((err, res) => {_x000D_
  if (err) throw new Error(err);_x000D_
  console.log(res);_x000D_
});

_x000D_

The server request object then looks like {request: { ... query: { accessToken: abcfed } ... } }

Adding a favicon to a static HTML page

Try to use the <link rel="icon" type="image/ico" href="images/favi.ico"/>

"Cannot GET /" with Connect on Node.js

You typically want to render templates like this:

app.get('/', function(req, res){
  res.render('index.ejs');
});

However you can also deliver static content - to do so use:

app.use(express.static(__dirname + '/public'));

Now everything in the /public directory of your project will be delivered as static content at the root of your site e.g. if you place default.htm in the public folder if will be available by visiting /default.htm

Take a look through the express API and Connect Static middleware docs for more info.

best way to preserve numpy arrays on disk

Another possibility to store numpy arrays efficiently is Bloscpack:

#!/usr/bin/python
import numpy as np
import bloscpack as bp
import time

n = 10000000

a = np.arange(n)
b = np.arange(n) * 10
c = np.arange(n) * -0.5
tsizeMB = sum(i.size*i.itemsize for i in (a,b,c)) / 2**20.

blosc_args = bp.DEFAULT_BLOSC_ARGS
blosc_args['clevel'] = 6
t = time.time()
bp.pack_ndarray_file(a, 'a.blp', blosc_args=blosc_args)
bp.pack_ndarray_file(b, 'b.blp', blosc_args=blosc_args)
bp.pack_ndarray_file(c, 'c.blp', blosc_args=blosc_args)
t1 = time.time() - t
print "store time = %.2f (%.2f MB/s)" % (t1, tsizeMB / t1)

t = time.time()
a1 = bp.unpack_ndarray_file('a.blp')
b1 = bp.unpack_ndarray_file('b.blp')
c1 = bp.unpack_ndarray_file('c.blp')
t1 = time.time() - t
print "loading time = %.2f (%.2f MB/s)" % (t1, tsizeMB / t1)

and the output for my laptop (a relatively old MacBook Air with a Core2 processor):

$ python store-blpk.py
store time = 0.19 (1216.45 MB/s)
loading time = 0.25 (898.08 MB/s)

that means that it can store really fast, i.e. the bottleneck is typically the disk. However, as the compression ratios are pretty good here, the effective speed is multiplied by the compression ratios. Here are the sizes for these 76 MB arrays:

$ ll -h *.blp
-rw-r--r--  1 faltet  staff   921K Mar  6 13:50 a.blp
-rw-r--r--  1 faltet  staff   2.2M Mar  6 13:50 b.blp
-rw-r--r--  1 faltet  staff   1.4M Mar  6 13:50 c.blp

Please note that the use of the Blosc compressor is fundamental for achieving this. The same script but using 'clevel' = 0 (i.e. disabling compression):

$ python bench/store-blpk.py
store time = 3.36 (68.04 MB/s)
loading time = 2.61 (87.80 MB/s)

is clearly bottlenecked by the disk performance.

Node JS Error: ENOENT

change

"/tmp/test.jpg".

"./tmp/test.jpg"

Spring 3 MVC resources and tag <mvc:resources />

It works for me:

<mvc:resources mapping="/static/**" location="/static/"/>
<mvc:default-servlet-handler />
<mvc:annotation-driven />

Strange Characters in database text: Ã, Ã, ¢, â‚ €,

The error usually gets introduced while creation of CSV. Try using Linux for saving the CSV as a TextCSV. Libre Office in Ubuntu can enforce the encoding to be UTF-8, worked for me. I wasted a lot of time trying this on Mac OS. Linux is the key. I've tested on Ubuntu.

Good Luck

Tuning nginx worker_process to obtain 100k hits per min

Config file:

worker_processes  4;  # 2 * Number of CPUs

events {
    worker_connections  19000;  # It's the key to high performance - have a lot of connections available
}

worker_rlimit_nofile    20000;  # Each connection needs a filehandle (or 2 if you are proxying)


# Total amount of users you can serve = worker_processes * worker_connections

more info: Optimizing nginx for high traffic loads

Apply function to each column in a data frame observing each columns existing data type

If you want to learn your data summary (df) provides the min, 1st quantile, median and mean, 3rd quantile and max of numerical columns and the frequency of the top levels of the factor columns.

IIS7: A process serving application pool 'YYYYY' suffered a fatal communication error with the Windows Process Activation Service

Debug Diagnostics Tool (DebugDiag) can be a lifesaver. It creates and analyze IIS crash dumps. I figured out my crash in minutes once I saw the call stack. https://support.microsoft.com/en-us/kb/919789

jQuery get content between <div> tags

var x = '<p>blah</p><div><a href="http://bs.serving-sys.com/BurstingPipe/adServer.bs?cn=brd&FlightID=2997227&Page=&PluID=0&Pos=9088" target="_blank"><img src="http://bs.serving-sys.com/BurstingPipe/adServer.bs?cn=bsr&FlightID=2997227&Page=&PluID=0&Pos=9088" border=0 width=300 height=250></a></div>';
$(x).children('div').html();

PHP Get Highest Value from Array

You are looking for asort()

How to create a HTTP server in Android?

Consider this one: https://github.com/NanoHttpd/nanohttpd. Very small, written in Java. I used it without any problem.

How to clear the cache of nginx?

We use nginx for caching lots of stuff. There are tens of thousands of items in the cache directory. To find items and delete them, we have developed some scripts to simplify this process. You can find link to the code repository containing these scripts below:

https://github.com/zafergurel/nginx-cache-cleaner

The idea is simple. To create an index of the cache (with cache keys and corresponding cache files) and search within this index file. It really helped us to speed-up finding items (from minutes to sub-second) and delete them accordingly.

When should I use a trailing slash in my URL?

The trailing slash does not matter for your root domain or subdomain. Google sees the two as equivalent.

But trailing slashes do matter for everything else because Google sees the two versions (one with a trailing slash and one without) as being different URLs. Conventionally, a trailing slash (/) at the end of a URL meant that the URL was a folder or directory.

A URL without a trailing slash at the end used to mean that the URL was a file.

Google recommendation

How to install mod_ssl for Apache httpd?

Are any other LoadModule commands referencing modules in the /usr/lib/httpd/modules folder? If so, you should be fine just adding LoadModule ssl_module /usr/lib/httpd/modules/mod_ssl.so to your conf file.

Otherwise, you'll want to copy the mod_ssl.so file to whatever directory the other modules are being loaded from and reference it there.

batch/bat to copy folder and content at once

I suspect that the xcopy command is the magic bullet you're looking for.

It can copy files, directories, and even entire drives while preserving the original directory hierarchy. There are also a handful of additional options available, compared to the basic copy command.

Check out the documentation here.

If your batch file only needs to run on Windows Vista or later, you can use robocopy instead, which is an even more powerful tool than xcopy, and is now built into the operating system. It's documentation is available here.

LD_LIBRARY_PATH vs LIBRARY_PATH

LD_LIBRARY_PATH is searched when the program starts, LIBRARY_PATH is searched at link time.

caveat from comments:

When linking libraries with ld (instead of gcc or g++), the LIBRARY_PATH or LD_LIBRARY_PATH environment variables are not read.
When linking libraries with gcc or g++, the LIBRARY_PATH environment variable is read (see documentation "gcc uses these directories when searching for ordinary libraries").

Is there a way to cast float as a decimal without rounding and preserving its precision?

cast (field1 as decimal(53,8)
) field 1

The default is: decimal(18,0)

Mime type for WOFF fonts?

Thing that did it for me was to add this to my mime_types.rb initializer:

Rack::Mime::MIME_TYPES['.woff'] = 'font/woff'

and wipe out the cache

rake tmp:cache:clear

before restarting the server.

Source: https://github.com/sstephenson/sprockets/issues/366#issuecomment-9085509

C: convert double to float, preserving decimal point precision

Floating point numbers are represented in scientific notation as a number of only seven significant digits multiplied by a larger number that represents the place of the decimal place. More information about it on Wikipedia:

http://en.wikipedia.org/wiki/Floating_point

Text Progress Bar in the Console

Putting together some of the ideas I found here, and adding estimated time left:

import datetime, sys

start = datetime.datetime.now()

def print_progress_bar (iteration, total):

    process_duration_samples = []
    average_samples = 5

    end = datetime.datetime.now()

    process_duration = end - start

    if len(process_duration_samples) == 0:
        process_duration_samples = [process_duration] * average_samples

    process_duration_samples = process_duration_samples[1:average_samples-1] + [process_duration]
    average_process_duration = sum(process_duration_samples, datetime.timedelta()) / len(process_duration_samples)
    remaining_steps = total - iteration
    remaining_time_estimation = remaining_steps * average_process_duration

    bars_string = int(float(iteration) / float(total) * 20.)
    sys.stdout.write(
        "\r[%-20s] %d%% (%s/%s) Estimated time left: %s" % (
            '='*bars_string, float(iteration) / float(total) * 100,
            iteration,
            total,
            remaining_time_estimation
        ) 
    )
    sys.stdout.flush()
    if iteration + 1 == total:
        print 


# Sample usage

for i in range(0,300):
    print_progress_bar(i, 300)

Unicode characters in URLs

Depending on your URL scheme, you can make the UTF-8 encoded part "not important". For example, if you look at Stack Overflow URLs, they're of the following form:

http://stackoverflow.com/questions/2742852/unicode-characters-in-urls

However, the server doesn't actually care if you get the part after the identifier wrong, so this also works:

http://stackoverflow.com/questions/2742852/?????????????????

So if you had a layout like this, then you could potentially use UTF-8 in the part after the identifier and it wouldn't really matter if it got garbled. Of course this probably only works in somewhat specialised circumstances...

Add querystring parameters to link_to

The API docs on link_to show some examples of adding querystrings to both named and oldstyle routes. Is this what you want?

link_to can also produce links with anchors or query strings:

link_to "Comment wall", profile_path(@profile, :anchor => "wall")
#=> <a href="/profiles/1#wall">Comment wall</a>

link_to "Ruby on Rails search", :controller => "searches", :query => "ruby on rails"
#=> <a href="/searches?query=ruby+on+rails">Ruby on Rails search</a>

link_to "Nonsense search", searches_path(:foo => "bar", :baz => "quux")
#=> <a href="/searches?foo=bar&amp;baz=quux">Nonsense search</a>

Block direct access to a file over http but allow php script access

in httpd.conf to block browser & wget access to include files especially say db.inc or config.inc . Note you cannot chain file types in the directive instead create multiple file directives.

<Files ~ "\.inc$">
Order allow,deny
Deny from all
</Files>

to test your config before restarting apache

service httpd configtest

then (graceful restart)

service httpd graceful

ISO time (ISO 8601) in Python

ISO 8601 Time Representation

The international standard ISO 8601 describes a string representation for dates and times. Two simple examples of this format are

2010-12-16 17:22:15
20101216T172215

(which both stand for the 16th of December 2010), but the format also allows for sub-second resolution times and to specify time zones. This format is of course not Python-specific, but it is good for storing dates and times in a portable format. Details about this format can be found in the Markus Kuhn entry.

I recommend use of this format to store times in files.

One way to get the current time in this representation is to use strftime from the time module in the Python standard library:

>>> from time import strftime
>>> strftime("%Y-%m-%d %H:%M:%S")
'2010-03-03 21:16:45'

You can use the strptime constructor of the datetime class:

>>> from datetime import datetime
>>> datetime.strptime("2010-06-04 21:08:12", "%Y-%m-%d %H:%M:%S")
datetime.datetime(2010, 6, 4, 21, 8, 12)

The most robust is the Egenix mxDateTime module:

>>> from mx.DateTime.ISO import ParseDateTimeUTC
>>> from datetime import datetime
>>> x = ParseDateTimeUTC("2010-06-04 21:08:12")
>>> datetime.fromtimestamp(x)
datetime.datetime(2010, 3, 6, 21, 8, 12)

References

c# Image resizing to different size while preserving aspect ratio

I created a extension method that is much simpiler than the answers that are posted. and the aspect ratio is applied without cropping the image.

public static Image Resize(this Image image, int width, int height) {
     var scale = Math.Min(height / (float)image.Height, width / (float)image.Width);
     return image.GetThumbnailImage((int)(image.Width * scale), (int)(image.Height * scale), () => false, IntPtr.Zero);
}

Example usage:

using (var img = Image.FromFile(pathToOriginalImage)) {
    using (var thumbnail = img.Resize(60, 60)){
        // Here you can do whatever you need to do with thumnail
    }
}

Simplest way to serve static data from outside the application server in a Java web application

I've seen some suggestions like having the image directory being a symbolic link pointing to a directory outside the web container, but will this approach work both on Windows and *nix environments?

If you adhere the *nix filesystem path rules (i.e. you use exclusively forward slashes as in /path/to/files), then it will work on Windows as well without the need to fiddle around with ugly File.separator string-concatenations. It would however only be scanned on the same working disk as from where this command is been invoked. So if Tomcat is for example installed on C: then the /path/to/files would actually point to C:\path\to\files.

If the files are all located outside the webapp, and you want to have Tomcat's DefaultServlet to handle them, then all you basically need to do in Tomcat is to add the following Context element to /conf/server.xml inside <Host> tag:

<Context docBase="/path/to/files" path="/files" />

This way they'll be accessible through http://example.com/files/.... For Tomcat-based servers such as JBoss EAP 6.x or older, the approach is basically the same, see also here. GlassFish/Payara configuration example can be found here and WildFly configuration example can be found here.

If you want to have control over reading/writing files yourself, then you need to create a Servlet for this which basically just gets an InputStream of the file in flavor of for example FileInputStream and writes it to the OutputStream of the HttpServletResponse.

On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.

Here's a basic example of such a servlet:

@WebServlet("/files/*")
public class FileServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        String filename = URLDecoder.decode(request.getPathInfo().substring(1), "UTF-8");
        File file = new File("/path/to/files", filename);
        response.setHeader("Content-Type", getServletContext().getMimeType(filename));
        response.setHeader("Content-Length", String.valueOf(file.length()));
        response.setHeader("Content-Disposition", "inline; filename=\"" + file.getName() + "\"");
        Files.copy(file.toPath(), response.getOutputStream());
    }

}

When mapped on an url-pattern of for example /files/*, then you can call it by http://example.com/files/image.png. This way you can have more control over the requests than the DefaultServlet does, such as providing a default image (i.e. if (!file.exists()) file = new File("/path/to/files", "404.gif") or so). Also using the request.getPathInfo() is preferred above request.getParameter() because it is more SEO friendly and otherwise IE won't pick the correct filename during Save As.

You can reuse the same logic for serving files from database. Simply replace new FileInputStream() by ResultSet#getInputStream().

Hope this helps.

Android WebView Cookie Problem

Note that it may be better use subdomains instead of usual URL. So, set .example.com instead of https://example.com/.

Thanks to Jody Jacobus Geers and others I wrote so:

if (savedInstanceState == null) {
    val cookieManager = CookieManager.getInstance()
    cookieManager.acceptCookie()
    val domain = ".example.com"
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        cookieManager.setCookie(domain, "token=$token") {
            view.webView.loadUrl(url)
        }
        cookieManager.setAcceptThirdPartyCookies(view.webView, true)
    } else {
        cookieManager.setCookie(domain, "token=$token")
        view.webView.loadUrl(url)
    }
} else {
    // Check whether we're recreating a previously destroyed instance.
    view.webView.restoreState(savedInstanceState)
}

Move existing, uncommitted work to a new branch in Git

Update 2020 / Git 2.23

Git 2.23 adds the new switch subcommand in an attempt to clear some of the confusion that comes from the overloaded usage of checkout (switching branches, restoring files, detaching HEAD, etc.)

Starting with this version of Git, replace above's command with:

git switch -c <new-branch>

The behavior is identical and remains unchanged.

Before Update 2020 / Git 2.23

Use the following:

git checkout -b <new-branch>

This will leave your current branch as it is, create and checkout a new branch and keep all your changes. You can then stage changes in files to commit with:

git add <files>

and commit to your new branch with:

git commit -m "<Brief description of this commit>"

The changes in the working directory and changes staged in index do not belong to any branch yet. This changes the branch where those modifications would end in.

You don't reset your original branch, it stays as it is. The last commit on <old-branch> will still be the same. Therefore you checkout -b and then commit.

How to move files from one git repo to another (not a clone), preserving history

This answer provide interesting commands based on git am and presented using examples, step by step.

Objective

You want to move some or all files from one repository to another.
You want to keep their history.
But you do not care about keeping tags and branches.
You accept limited history for renamed files (and files in renamed directories).

Procedure

Extract history in email format using
git log --pretty=email -p --reverse --full-index --binary
Reorganize file tree and update filename change in history [optional]
Apply new history using git am

1. Extract history in email format

Example: Extract history of file3, file4 and file5

my_repo
+-- dirA
¦   +-- file1
¦   +-- file2
+-- dirB            ^
¦   +-- subdir      | To be moved
¦   ¦   +-- file3   | with history
¦   ¦   +-- file4   | 
¦   +-- file5       v
+-- dirC
    +-- file6
    +-- file7

Clean the temporary directory destination

export historydir=/tmp/mail/dir  # Absolute path
rm -rf "$historydir"             # Caution when cleaning

Clean your the repo source

git commit ...           # Commit your working files
rm .gitignore            # Disable gitignore
git clean -n             # Simulate removal
git clean -f             # Remove untracked file
git checkout .gitignore  # Restore gitignore

Extract history of each file in email format

cd my_repo/dirB
find -name .git -prune -o -type d -o -exec bash -c 'mkdir -p "$historydir/${0%/*}" && git log --pretty=email -p --stat --reverse --full-index --binary -- "$0" > "$historydir/$0"' {} ';'

Unfortunately option --follow or --find-copies-harder cannot be combined with --reverse. This is why history is cut when file is renamed (or when a parent directory is renamed).

After: Temporary history in email format

/tmp/mail/dir
    +-- subdir
    ¦   +-- file3
    ¦   +-- file4
    +-- file5

2. Reorganize file tree and update filename change in history [optional]

Suppose you want to move these three files in this other repo (can be the same repo).

my_other_repo
+-- dirF
¦   +-- file55
¦   +-- file56
+-- dirB              # New tree
¦   +-- dirB1         # was subdir
¦   ¦   +-- file33    # was file3
¦   ¦   +-- file44    # was file4
¦   +-- dirB2         # new dir
¦        +-- file5    # = file5
+-- dirH
    +-- file77

Therefore reorganize your files:

cd /tmp/mail/dir
mkdir     dirB
mv subdir dirB/dirB1
mv dirB/dirB1/file3 dirB/dirB1/file33
mv dirB/dirB1/file4 dirB/dirB1/file44
mkdir    dirB/dirB2
mv file5 dirB/dirB2

Your temporary history is now:

/tmp/mail/dir
    +-- dirB
        +-- dirB1
        ¦   +-- file33
        ¦   +-- file44
        +-- dirB2
             +-- file5

Change also filenames within the history:

cd "$historydir"
find * -type f -exec bash -c 'sed "/^diff --git a\|^--- a\|^+++ b/s:\( [ab]\)/[^ ]*:\1/$0:g" -i "$0"' {} ';'

Note: This rewrites the history to reflect the change of path and filename.
^{(i.e. the change of the new location/name within the new repo)}

3. Apply new history

Your other repo is:

my_other_repo
+-- dirF
¦   +-- file55
¦   +-- file56
+-- dirH
    +-- file77

Apply commits from temporary history files:

cd my_other_repo
find "$historydir" -type f -exec cat {} + | git am

Your other repo is now:

my_other_repo
+-- dirF
¦   +-- file55
¦   +-- file56
+-- dirB            ^
¦   +-- dirB1       | New files
¦   ¦   +-- file33  | with
¦   ¦   +-- file44  | history
¦   +-- dirB2       | kept
¦        +-- file5  v
+-- dirH
    +-- file77

Use git status to see amount of commits ready to be pushed :-)

Note: As the history has been rewritten to reflect the path and filename change:
^{(i.e. compared to the location/name within the previous repo)}

No need to git mv to change the location/filename.
No need to git log --follow to access full history.

Extra trick: Detect renamed/moved files within your repo

To list the files having been renamed:

find -name .git -prune -o -exec git log --pretty=tformat:'' --numstat --follow {} ';' | grep '=>'

More customizations: You can complete the command git log using options --find-copies-harder or --reverse. You can also remove the first two columns using cut -f3- and grepping complete pattern '{.* => .*}'.

find -name .git -prune -o -exec git log --pretty=tformat:'' --numstat --follow --find-copies-harder --reverse {} ';' | cut -f3- | grep '{.* => .*}'

How to Rotate a UIImage 90 degrees?

As strange as this seems, the following code solved the problem for me:

+ (UIImage*)unrotateImage:(UIImage*)image {
    CGSize size = image.size;
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0,0,size.width ,size.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

Rethrowing exceptions in Java without losing the stack trace

catch (WhateverException e) {
    throw e;
}

will simply rethrow the exception you've caught (obviously the surrounding method has to permit this via its signature etc.). The exception will maintain the original stack trace.

Uses of content-disposition in an HTTP response header

Refer to RFC 6266 (Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)) http://tools.ietf.org/html/rfc6266

Enter key press behaves like a Tab in Javascript

Map [Enter] key to work like the [Tab] key

I've rewritten Andre Van Zuydam's answer, which didn't work for me, in jQuery. This caputures both Enter and Shift+Enter. Enter tabs forward, and Shift+Enter tabs back.

I've also rewritten the way self is initialized by the current item in focus. The form is also selected that way. Here's the code:

// Map [Enter] key to work like the [Tab] key
// Daniel P. Clark 2014

// Catch the keydown for the entire document
$(document).keydown(function(e) {

  // Set self as the current item in focus
  var self = $(':focus'),
      // Set the form by the current item in focus
      form = self.parents('form:eq(0)'),
      focusable;

  // Array of Indexable/Tab-able items
  focusable = form.find('input,a,select,button,textarea,div[contenteditable=true]').filter(':visible');

  function enterKey(){
    if (e.which === 13 && !self.is('textarea,div[contenteditable=true]')) { // [Enter] key

      // If not a regular hyperlink/button/textarea
      if ($.inArray(self, focusable) && (!self.is('a,button'))){
        // Then prevent the default [Enter] key behaviour from submitting the form
        e.preventDefault();
      } // Otherwise follow the link/button as by design, or put new line in textarea

      // Focus on the next item (either previous or next depending on shift)
      focusable.eq(focusable.index(self) + (e.shiftKey ? -1 : 1)).focus();

      return false;
    }
  }
  // We need to capture the [Shift] key and check the [Enter] key either way.
  if (e.shiftKey) { enterKey() } else { enterKey() }
});

The reason `textarea`

is included is because we "do" want to tab into it. Also, once in, we don't want to stop the default behavior of Enter from putting in a new line.

The reason `a` and `button`

allow the default action, "and" still focus on the next item, is because they don't always load another page. There can be a trigger/effect on those such as an accordion or tabbed content. So once you trigger the default behavior, and the page does its special effect, you still want to go to the next item since your trigger may have well introduced it.

How to redirect a URL path in IIS?

Format the redirect URL in the following way:

stuff.mysite.org.uk$S$Q

The $S will say that any path must be applied to the new URL. $Q says that any parameter variables must be passed to the new URL.

In IIS 7.0, you must enable the option Redirect to exact destination. I believe there must be an option like this in IIS 6.0 too.

How can I reverse the order of lines in a file?

This will work on both BSD and GNU.

awk '{arr[i++]=$0} END {while (i>0) print arr[--i] }' filename

How do I make an http request using cookies on Android?

It turns out that Google Android ships with Apache HttpClient 4.0, and I was able to figure out how to do it using the "Form based logon" example in the HttpClient docs:

https://github.com/apache/httpcomponents-client/blob/master/httpclient5/src/test/java/org/apache/hc/client5/http/examples/ClientFormLogin.java

import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;

/**
 * A example that demonstrates how HttpClient APIs can be used to perform
 * form-based logon.
 */
public class ClientFormLogin {

    public static void main(String[] args) throws Exception {

        DefaultHttpClient httpclient = new DefaultHttpClient();

        HttpGet httpget = new HttpGet("https://portal.sun.com/portal/dt");

        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();

        System.out.println("Login form get: " + response.getStatusLine());
        if (entity != null) {
            entity.consumeContent();
        }
        System.out.println("Initial set of cookies:");
        List<Cookie> cookies = httpclient.getCookieStore().getCookies();
        if (cookies.isEmpty()) {
            System.out.println("None");
        } else {
            for (int i = 0; i < cookies.size(); i++) {
                System.out.println("- " + cookies.get(i).toString());
            }
        }

        HttpPost httpost = new HttpPost("https://portal.sun.com/amserver/UI/Login?" +
                "org=self_registered_users&" +
                "goto=/portal/dt&" +
                "gotoOnFail=/portal/dt?error=true");

        List <NameValuePair> nvps = new ArrayList <NameValuePair>();
        nvps.add(new BasicNameValuePair("IDToken1", "username"));
        nvps.add(new BasicNameValuePair("IDToken2", "password"));

        httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));

        response = httpclient.execute(httpost);
        entity = response.getEntity();

        System.out.println("Login form get: " + response.getStatusLine());
        if (entity != null) {
            entity.consumeContent();
        }

        System.out.println("Post logon cookies:");
        cookies = httpclient.getCookieStore().getCookies();
        if (cookies.isEmpty()) {
            System.out.println("None");
        } else {
            for (int i = 0; i < cookies.size(); i++) {
                System.out.println("- " + cookies.get(i).toString());
            }
        }

        // When HttpClient instance is no longer needed, 
        // shut down the connection manager to ensure
        // immediate deallocation of all system resources
        httpclient.getConnectionManager().shutdown();        
    }
}

Is it more efficient to copy a vector by reserving and copying, or by creating and swapping?

Your second example does not work if you send the argument by reference. Did you mean

void copyVecFast(vec<int> original) // no reference
{

  vector<int> new_;
  new_.swap(original); 
}

That would work, but an easier way is

vector<int> new_(original);

Serving favicon.ico in ASP.NET MVC

Placing favicon.ico in the root of your domain only really affects IE5, IIRC. For more modern browsers you should be able to include a link tag to point to another directory:

<link rel="SHORTCUT ICON" href="http://www.mydomain.com/content/favicon.ico"/>

You can also use non-ico files for browsers other than IE, for which I'd maybe use the following conditional statement to serve a PNG to FF,etc, and an ICO to IE:

<link rel="icon" type="image/png" href="http://www.mydomain.com/content/favicon.png" />
<!--[if IE]>
<link rel="shortcut icon" href="http://www.mydomain.com/content/favicon.ico" type="image/vnd.microsoft.icon" />
<![endif]-->

How do you remove duplicates from a list whilst preserving order?

Not to kick a dead horse (this question is very old and already has lots of good answers), but here is a solution using pandas that is quite fast in many circumstances and is dead simple to use.

import pandas as pd

my_list = [0, 1, 2, 3, 4, 1, 2, 3, 5]

>>> pd.Series(my_list).drop_duplicates().tolist()
# Output:
# [0, 1, 2, 3, 4, 5]

How to find event listeners on a DOM node when debugging or from the JavaScript code?

WebKit Inspector in Chrome or Safari browsers now does this. It will display the event listeners for a DOM element when you select it in the Elements pane.

How do you display code snippets in MS Word preserving format and syntax highlighting?

You can use VS code to keep code format and highlighting. Directly copy and paste code from VS.

Servlet for serving static content

I had the same problem and I solved it by using the code of the 'default servlet' from the Tomcat codebase.

https://github.com/apache/tomcat/blob/master/java/org/apache/catalina/servlets/DefaultServlet.java

The DefaultServlet is the servlet that serves the static resources (jpg,html,css,gif etc) in Tomcat.

This servlet is very efficient and has some the properties you defined above.

I think that this source code, is a good way to start and remove the functionality or depedencies you don't need.

References to the org.apache.naming.resources package can be removed or replaced with java.io.File code.
References to the org.apache.catalina.util package are propably only utility methods/classes that can be duplicated in your source code.
References to the org.apache.catalina.Globals class can be inlined or removed.

Top 5 Mobile App Development Companies In the UK 2024

Good tool for testing socket connections?

Hercules is fantastic. It's a fully functioning tcp/udp client/server, amazing for debugging sockets. More details on the web site.

How to debug PDO database queries?

The problem I had with the solution to catch PDO exemptions for debuging purposes is that it only caught PDO exemptions (duh), but didn't catch syntax errors which were registered as php errors (I'm not sure why this is, but "why" is irrelevant to the solution). All my PDO calls come from a single table model class that I extended for all my interactions with all tables... this complicated things when I was trying to debug code, because the error would register the line of php code where my execute call was called, but didn't tell me where the call was, actually, being made from. I used the following code to solve this problem:

/**
 * Executes a line of sql with PDO.
 * 
 * @param string $sql
 * @param array $params
 */
class TableModel{
    var $_db; //PDO connection
    var $_query; //PDO query

    function execute($sql, $params) { 
        //we're saving this as a global, so it's available to the error handler
        global $_tm;
        //setting these so they're available to the error handler as well
        $this->_sql = $sql;
        $this->_paramArray = $params;            

        $this->_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $this->_query = $this->_db->prepare($sql);

        try {
            //set a custom error handler for pdo to catch any php errors
            set_error_handler('pdoErrorHandler');

            //save the table model object to make it available to the pdoErrorHandler
            $_tm = $this;
            $this->_query->execute($params);

            //now we restore the normal error handler
            restore_error_handler();
        } catch (Exception $ex) {
            pdoErrorHandler();
            return false;
        }            
    }
}

So, the above code catches BOTH PDO exceptions AND php syntax errors and treats them the same way. My error handler looks something like this:

function pdoErrorHandler() {
    //get all the stuff that we set in the table model
    global $_tm;
    $sql = $_tm->_sql;
    $params = $_tm->_params;
    $query = $tm->_query;

    $message = 'PDO error: ' . $sql . ' (' . implode(', ', $params) . ") \n";

    //get trace info, so we can know where the sql call originated from
    ob_start();
    debug_backtrace(); //I have a custom method here that parses debug backtrace, but this will work as well
    $trace = ob_get_clean();

    //log the error in a civilized manner
    error_log($message);

    if(admin(){
        //print error to screen based on your environment, logged in credentials, etc.
        print_r($message);
    }
}

If anyone has any better ideas on how to get relevant info to my error handler than setting the table model as a global variable, I would be happy to hear it and edit my code.

Equivalent to AssemblyInfo in dotnet core/csproj

You can always add your own AssemblyInfo.cs, which comes in handy for InternalsVisibleToAttribute, CLSCompliantAttribute and others that are not automatically generated.

Adding AssemblyInfo.cs to a Project

In Solution Explorer, right click on <project name> > Add > New Folder.

Name the folder "Properties".

Right click on the "Properties" folder, and click Add > New Item....

Select "Class" and name it "AssemblyInfo.cs".

Suppressing Auto-Generated Attributes

If you want to move your attributes back to AssemblyInfo.cs instead of having them auto-generated, you can suppress them in MSBuild as natemcmaster pointed out in his answer.

How can I compare a date and a datetime in Python?

Here is another take, "stolen" from a comment at can't compare datetime.datetime to datetime.date ... convert the date to a datetime using this construct:

datetime.datetime(d.year, d.month, d.day)

Suggestion:

from datetime import datetime

def ensure_datetime(d):
    """
    Takes a date or a datetime as input, outputs a datetime
    """
    if isinstance(d, datetime):
        return d
    return datetime.datetime(d.year, d.month, d.day)

def datetime_cmp(d1, d2):
    """
    Compares two timestamps.  Tolerates dates.
    """
    return cmp(ensure_datetime(d1), ensure_datetime(d2))

Count frequency of words in a list and sort by frequency

Using Counter would be the best way, but if you don't want to do that, you can implement it yourself this way.

# The list you already have
word_list = ['words', ..., 'other', 'words']
# Get a set of unique words from the list
word_set = set(word_list)
# create your frequency dictionary
freq = {}
# iterate through them, once per unique word.
for word in word_set:
    freq[word] = word_list.count(word) / float(len(word_list))

freq will end up with the frequency of each word in the list you already have.

You need float in there to convert one of the integers to a float, so the resulting value will be a float.

Edit:

If you can't use a dict or set, here is another less efficient way:

# The list you already have
word_list = ['words', ..., 'other', 'words']
unique_words = []
for word in word_list:
    if word not in unique_words:
        unique_words += [word]
word_frequencies = []
for word in unique_words:
    word_frequencies += [float(word_list.count(word)) / len(word_list)]
for i in range(len(unique_words)):
    print(unique_words[i] + ": " + word_frequencies[i])

The indicies of unique_words and word_frequencies will match.

Print specific part of webpage

I wrote a tiny JavaScript module called PrintElements for dynamically printing parts of a webpage.

It works by iterating through selected node elements, and for each node, it traverses up the DOM tree until the BODY element. At each level, including the initial one (which is the to-be-printed node’s level), it attaches a marker class (pe-preserve-print) to the current node. Then attaches another marker class (pe-no-print) to all siblings of the current node, but only if there is no pe-preserve-print class on them. As a third act, it also attaches another class to preserved ancestor elements pe-preserve-ancestor.

A dead-simple supplementary print-only css will hide and show respective elements. Some benefits of this approach is that all styles are preserved, it does not open a new window, there is no need to move around a lot of DOM elements, and generally it is non-invasive with your original document.

See the demo, or read the related article for further details.

Anaconda version with Python 3.5

Per this announcement, Anaconda upgraded to Python 3.6 starting with version 4.3, so... you probably want the 4.2.0 package from the installer archive.

Encoding conversion in java

CharsetDecoder should be what you are looking for, no ?

Many network protocols and files store their characters with a byte-oriented character set such as ISO-8859-1 (ISO-Latin-1).
However, Java's native character encoding is ~~Unicode~~ UTF16BE (Sixteen-bit UCS Transformation Format, big-endian byte order).

See Charset. That doesn't mean UTF16 is the default charset (i.e.: the default "mapping between sequences of sixteen-bit Unicode code units and sequences of bytes"):

Every instance of the Java virtual machine has a default charset, which may or may not be one of the standard charsets.
[US-ASCII, ISO-8859-1 a.k.a. ISO-LATIN-1, UTF-8, UTF-16BE, UTF-16LE, UTF-16]
The default charset is determined during virtual-machine startup and typically depends upon the locale and charset being used by the underlying operating system.

This example demonstrates how to convert ISO-8859-1 encoded bytes in a ByteBuffer to a string in a CharBuffer and visa versa.

// Create the encoder and decoder for ISO-8859-1
Charset charset = Charset.forName("ISO-8859-1");
CharsetDecoder decoder = charset.newDecoder();
CharsetEncoder encoder = charset.newEncoder();

try {
    // Convert a string to ISO-LATIN-1 bytes in a ByteBuffer
    // The new ByteBuffer is ready to be read.
    ByteBuffer bbuf = encoder.encode(CharBuffer.wrap("a string"));

    // Convert ISO-LATIN-1 bytes in a ByteBuffer to a character ByteBuffer and then to a string.
    // The new ByteBuffer is ready to be read.
    CharBuffer cbuf = decoder.decode(bbuf);
    String s = cbuf.toString();
} catch (CharacterCodingException e) {
}

SecurityException: Permission denied (missing INTERNET permission?)

Just like Tom mentioned. When you start with capital A then autocomplete will complete it as.

ANDROID.PERMISSION.INTERNET

When you start typing with a then autocomplete will complete it as

android.permission.INTERNET

The second one is the correct one.

Where's the IE7/8/9/10-emulator in IE11 dev tools?

I posted an answer to this already when someone else asked the same question (see How to bring back "Browser mode" in IE11?).

Read my answer there for a fuller explaination, but in short:

They removed it deliberately, because compat mode is not actually really very good for testing compatibility.
If you really want to test for compatibility with any given version of IE, you need to test in a real copy of that IE version. MS provide free VMs on http://modern.ie/ for you to use for this purpose.
The only way to get compat mode in IE11 is to set the X-UA-Compatible header. When you have this and the site defaults to compat mode, you will be able to set the mode in dev tools, but only between edge or the specified compat mode; other modes will still not be available.

VBA Excel 2-Dimensional Arrays

Here's A generic VBA Array To Range function that writes an array to the sheet in a single 'hit' to the sheet. This is much faster than writing the data into the sheet one cell at a time in loops for the rows and columns... However, there's some housekeeping to do, as you must specify the size of the target range correctly.

This 'housekeeping' looks like a lot of work and it's probably rather slow: but this is 'last mile' code to write to the sheet, and everything is faster than writing to the worksheet. Or at least, so much faster that it's effectively instantaneous, compared with a read or write to the worksheet, even in VBA, and you should do everything you possibly can in code before you hit the sheet.

A major component of this is error-trapping that I used to see turning up everywhere . I hate repetitive coding: I've coded it all here, and - hopefully - you'll never have to write it again.

A VBA 'Array to Range' function

Public Sub ArrayToRange(rngTarget As Excel.Range, InputArray As Variant)
' Write an array to an Excel range in a single 'hit' to the sheet
' InputArray must be a 2-Dimensional structure of the form Variant(Rows, Columns)

' The target range is resized automatically to the dimensions of the array, with
' the top left cell used as the start point.

' This subroutine saves repetitive coding for a common VBA and Excel task.

' If you think you won't need the code that works around common errors (long strings
' and objects in the array, etc) then feel free to comment them out.

On Error Resume Next

'
' Author: Nigel Heffernan
' HTTP://Excellerando.blogspot.com
'
' This code is in te public domain: take care to mark it clearly, and segregate
' it from proprietary code if you intend to assert intellectual property rights
' or impose commercial confidentiality restrictions on that proprietary code

Dim rngOutput As Excel.Range

Dim iRowCount   As Long
Dim iColCount   As Long
Dim iRow        As Long
Dim iCol        As Long
Dim arrTemp     As Variant
Dim iDimensions As Integer

Dim iRowOffset  As Long
Dim iColOffset  As Long
Dim iStart      As Long


Application.EnableEvents = False
If rngTarget.Cells.Count > 1 Then
    rngTarget.ClearContents
End If
Application.EnableEvents = True

If IsEmpty(InputArray) Then
    Exit Sub
End If


If TypeName(InputArray) = "Range" Then
    InputArray = InputArray.Value
End If

' Is it actually an array? IsArray is sadly broken so...
If Not InStr(TypeName(InputArray), "(") Then
    rngTarget.Cells(1, 1).Value2 = InputArray
    Exit Sub
End If


iDimensions = ArrayDimensions(InputArray)

If iDimensions < 1 Then

    rngTarget.Value = CStr(InputArray)

ElseIf iDimensions = 1 Then

    iRowCount = UBound(InputArray) - LBound(InputArray)
    iStart = LBound(InputArray)
    iColCount = 1

    If iRowCount > (655354 - rngTarget.Row) Then
        iRowCount = 655354 + iStart - rngTarget.Row
        ReDim Preserve InputArray(iStart To iRowCount)
    End If

    iRowCount = UBound(InputArray) - LBound(InputArray)
    iColCount = 1

    ' It's a vector. Yes, I asked for a 2-Dimensional array. But I'm feeling generous.
    ' By convention, a vector is presented in Excel as an arry of 1 to n rows and 1 column.
    ReDim arrTemp(LBound(InputArray, 1) To UBound(InputArray, 1), 1 To 1)
    For iRow = LBound(InputArray, 1) To UBound(InputArray, 1)
        arrTemp(iRow, 1) = InputArray(iRow)
    Next

    With rngTarget.Worksheet
        Set rngOutput = .Range(rngTarget.Cells(1, 1), rngTarget.Cells(iRowCount + 1, iColCount))
        rngOutput.Value2 = arrTemp
        Set rngTarget = rngOutput
    End With

    Erase arrTemp

ElseIf iDimensions = 2 Then

    iRowCount = UBound(InputArray, 1) - LBound(InputArray, 1)
    iColCount = UBound(InputArray, 2) - LBound(InputArray, 2)

    iStart = LBound(InputArray, 1)

    If iRowCount > (65534 - rngTarget.Row) Then
        iRowCount = 65534 - rngTarget.Row
        InputArray = ArrayTranspose(InputArray)
        ReDim Preserve InputArray(LBound(InputArray, 1) To UBound(InputArray, 1), iStart To iRowCount)
        InputArray = ArrayTranspose(InputArray)
    End If


    iStart = LBound(InputArray, 2)
    If iColCount > (254 - rngTarget.Column) Then
        ReDim Preserve InputArray(LBound(InputArray, 1) To UBound(InputArray, 1), iStart To iColCount)
    End If



    With rngTarget.Worksheet

        Set rngOutput = .Range(rngTarget.Cells(1, 1), rngTarget.Cells(iRowCount + 1, iColCount + 1))

        Err.Clear
        Application.EnableEvents = False
        rngOutput.Value2 = InputArray
        Application.EnableEvents = True

        If Err.Number <> 0 Then
            For iRow = LBound(InputArray, 1) To UBound(InputArray, 1)
                For iCol = LBound(InputArray, 2) To UBound(InputArray, 2)
                    If IsNumeric(InputArray(iRow, iCol)) Then
                        ' no action
                    Else
                        InputArray(iRow, iCol) = "" & InputArray(iRow, iCol)
                        InputArray(iRow, iCol) = Trim(InputArray(iRow, iCol))
                    End If
                Next iCol
            Next iRow
            Err.Clear
            rngOutput.Formula = InputArray
        End If 'err<>0

        If Err <> 0 Then
            For iRow = LBound(InputArray, 1) To UBound(InputArray, 1)
                For iCol = LBound(InputArray, 2) To UBound(InputArray, 2)
                    If IsNumeric(InputArray(iRow, iCol)) Then
                        ' no action
                    Else
                        If Left(InputArray(iRow, iCol), 1) = "=" Then
                            InputArray(iRow, iCol) = "'" & InputArray(iRow, iCol)
                        End If
                        If Left(InputArray(iRow, iCol), 1) = "+" Then
                            InputArray(iRow, iCol) = "'" & InputArray(iRow, iCol)
                        End If
                        If Left(InputArray(iRow, iCol), 1) = "*" Then
                            InputArray(iRow, iCol) = "'" & InputArray(iRow, iCol)
                        End If
                    End If
                Next iCol
            Next iRow
            Err.Clear
            rngOutput.Value2 = InputArray
        End If 'err<>0

        If Err <> 0 Then
            For iRow = LBound(InputArray, 1) To UBound(InputArray, 1)
                For iCol = LBound(InputArray, 2) To UBound(InputArray, 2)

                    If IsObject(InputArray(iRow, iCol)) Then
                        InputArray(iRow, iCol) = "[OBJECT] " & TypeName(InputArray(iRow, iCol))
                    ElseIf IsArray(InputArray(iRow, iCol)) Then
                        InputArray(iRow, iCol) = Split(InputArray(iRow, iCol), ",")
                    ElseIf IsNumeric(InputArray(iRow, iCol)) Then
                        ' no action
                    Else
                        InputArray(iRow, iCol) = "" & InputArray(iRow, iCol)
                        If Len(InputArray(iRow, iCol)) > 255 Then
                            ' Block-write operations fail on strings exceeding 255 chars. You *have*
                            ' to go back and check, and write this masterpiece one cell at a time...
                            InputArray(iRow, iCol) = Left(Trim(InputArray(iRow, iCol)), 255)
                        End If
                    End If
                Next iCol
            Next iRow
            Err.Clear
            rngOutput.Text = InputArray
        End If 'err<>0

        If Err <> 0 Then
            Application.ScreenUpdating = False
            Application.Calculation = xlCalculationManual
            iRowOffset = LBound(InputArray, 1) - 1
            iColOffset = LBound(InputArray, 2) - 1
            For iRow = 1 To iRowCount
                If iRow Mod 100 = 0 Then
                    Application.StatusBar = "Filling range... " & CInt(100# * iRow / iRowCount) & "%"
                End If
                For iCol = 1 To iColCount
                    rngOutput.Cells(iRow, iCol) = InputArray(iRow + iRowOffset, iCol + iColOffset)
                Next iCol
            Next iRow
            Application.StatusBar = False
            Application.ScreenUpdating = True


        End If 'err<>0


        Set rngTarget = rngOutput   ' resizes the range This is useful, *most* of the time

    End With

End If

End Sub

You will need the source for ArrayDimensions:

This API declaration is required in the module header:

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
                   (Destination As Any, _
                    Source As Any, _
                    ByVal Length As Long)

...And here's the function itself:

Private Function ArrayDimensions(arr As Variant) As Integer
  '-----------------------------------------------------------------
  ' will return:
  ' -1 if not an array
  ' 0  if an un-dimmed array
  ' 1  or more indicating the number of dimensions of a dimmed array
  '-----------------------------------------------------------------


  ' Retrieved from Chris Rae's VBA Code Archive - http://chrisrae.com/vba
  ' Code written by Chris Rae, 25/5/00

  ' Originally published by R. B. Smissaert.
  ' Additional credits to Bob Phillips, Rick Rothstein, and Thomas Eyde on VB2TheMax

  Dim ptr As Long
  Dim vType As Integer

  Const VT_BYREF = &H4000&

  'get the real VarType of the argument
  'this is similar to VarType(), but returns also the VT_BYREF bit
  CopyMemory vType, arr, 2

  'exit if not an array
  If (vType And vbArray) = 0 Then
    ArrayDimensions = -1
    Exit Function
  End If

  'get the address of the SAFEARRAY descriptor
  'this is stored in the second half of the
  'Variant parameter that has received the array
  CopyMemory ptr, ByVal VarPtr(arr) + 8, 4

  'see whether the routine was passed a Variant
  'that contains an array, rather than directly an array
  'in the former case ptr already points to the SA structure.
  'Thanks to Monte Hansen for this fix

  If (vType And VT_BYREF) Then
    ' ptr is a pointer to a pointer
    CopyMemory ptr, ByVal ptr, 4
  End If

  'get the address of the SAFEARRAY structure
  'this is stored in the descriptor

  'get the first word of the SAFEARRAY structure
  'which holds the number of dimensions
  '...but first check that saAddr is non-zero, otherwise
  'this routine bombs when the array is uninitialized

  If ptr Then
    CopyMemory ArrayDimensions, ByVal ptr, 2
  End If

End Function

Also: I would advise you to keep that declaration private. If you must make it a public Sub in another module, insert the Option Private Module statement in the module header. You really don't want your users calling any function with CopyMemoryoperations and pointer arithmetic.

What's the Android ADB shell "dumpsys" tool and what are its benefits?

According to official Android information about dumpsys:

The dumpsys tool runs on the device and provides information about the status of system services.

To get a list of available services use

adb shell dumpsys -l

How can I open Java .class files in a human-readable way?

CFR - another java decompiler is a great decompiler for modern Java written i Java 6.

n-grams in python, four, five, six grams?

Nltk is great, but sometimes is a overhead for some projects:

import re
def tokenize(text, ngrams=1):
    text = re.sub(r'[\b\(\)\\\"\'\/\[\]\s+\,\.:\?;]', ' ', text)
    text = re.sub(r'\s+', ' ', text)
    tokens = text.split()
    return [tuple(tokens[i:i+ngrams]) for i in xrange(len(tokens)-ngrams+1)]

Example use:

>> text = "This is an example text"
>> tokenize(text, 2)
[('This', 'is'), ('is', 'an'), ('an', 'example'), ('example', 'text')]
>> tokenize(text, 3)
[('This', 'is', 'an'), ('is', 'an', 'example'), ('an', 'example', 'text')]

Java: Simplest way to get last word in a string

String testString = "This is a sentence";
String[] parts = testString.split(" ");
String lastWord = parts[parts.length - 1];
System.out.println(lastWord); // "sentence"

Passing parameters to a JQuery function

Do you want to pass parameters to another page or to the function only?

If only the function, you don't need to add the $.ajax() tvanfosson added. Just add your function content instead. Like:

function DoAction (id, name ) {
    // ...
    // do anything you want here
    alert ("id: "+id+" - name: "+name);
    //...
}

This will return an alert box with the id and name values.

How to edit the size of the submit button on a form?

I tried all the above no good. So I just add a padding individually:

 #button {

    font-size: 20px;
    color: white;
    background: crimson;
    border: 2px solid rgb(37, 34, 34);
    border-radius: 10px;
    padding-top: 10px;
    padding-bottom: 10px;
    padding-right: 10px;
    padding-left: 10px;
 }

How to iterate std::set?

You must dereference the iterator in order to retrieve the member of your set.

std::set<unsigned long>::iterator it;
for (it = SERVER_IPS.begin(); it != SERVER_IPS.end(); ++it) {
    u_long f = *it; // Note the "*" here
}

If you have C++11 features, you can use a range-based for loop:

for(auto f : SERVER_IPS) {
  // use f here
}

Increase max_execution_time in PHP?

For increasing execution time and file size, you need to mention below values in your .htaccess file. It will work.

php_value upload_max_filesize 80M
php_value post_max_size 80M
php_value max_input_time 18000
php_value max_execution_time 18000

How do I write stderr to a file while using "tee" with a pipe?

I'm assuming you want to still see STDERR and STDOUT on the terminal. You could go for Josh Kelley's answer, but I find keeping a tail around in the background which outputs your log file very hackish and cludgy. Notice how you need to keep an exra FD and do cleanup afterward by killing it and technically should be doing that in a trap '...' EXIT.

There is a better way to do this, and you've already discovered it: tee.

Only, instead of just using it for your stdout, have a tee for stdout and one for stderr. How will you accomplish this? Process substitution and file redirection:

command > >(tee -a stdout.log) 2> >(tee -a stderr.log >&2)

Let's split it up and explain:

> >(..)

>(...) (process substitution) creates a FIFO and lets tee listen on it. Then, it uses > (file redirection) to redirect the STDOUT of command to the FIFO that your first tee is listening on.

Same thing for the second:

2> >(tee -a stderr.log >&2)

We use process substitution again to make a tee process that reads from STDIN and dumps it into stderr.log. tee outputs its input back on STDOUT, but since its input is our STDERR, we want to redirect tee's STDOUT to our STDERR again. Then we use file redirection to redirect command's STDERR to the FIFO's input (tee's STDIN).

See http://mywiki.wooledge.org/BashGuide/InputAndOutput

Process substitution is one of those really lovely things you get as a bonus of choosing bash as your shell as opposed to sh (POSIX or Bourne).

In sh, you'd have to do things manually:

out="${TMPDIR:-/tmp}/out.$$" err="${TMPDIR:-/tmp}/err.$$"
mkfifo "$out" "$err"
trap 'rm "$out" "$err"' EXIT
tee -a stdout.log < "$out" &
tee -a stderr.log < "$err" >&2 &
command >"$out" 2>"$err"

Enum Naming Convention - Plural

Coming in a bit late...

There's an important difference between your question and the one you mention (which I asked ;-):

You put the enum definition out of the class, which allows you to have the same name for the enum and the property:

public enum EntityType { 
  Type1, Type2 
} 

public class SomeClass { 
  public EntityType EntityType {get; set;} // This is legal

}

In this case, I'd follow the MS guidelins and use a singular name for the enum (plural for flags). It's probaby the easiest solution.

My problem (in the other question) is when the enum is defined in the scope of the class, preventing the use of a property named exactly after the enum.

PHP Regex to check date is in YYYY-MM-DD format

To work with dates in php you should follow the php standard so the given regex will assure that you have valid date that can operate with PHP.

    preg_match("/^([0-9]{4})-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)

jQuery .attr("disabled", "disabled") not working in Chrome

if you are removing all disabled attributes from input, then why not just do:

$("input").removeAttr('disabled');

Then after ajax success:

$("input[type='text']").attr('disabled', true);

Make sure you use remove the disabled attribute before submit, or it won't submit that data. If you need to submit it before changing, you need to use readonly instead.

R command for setting working directory to source file location in Rstudio

If you work on Linux you can try this:

setwd(system("pwd", intern = T) )

It works for me.

Is there a replacement for unistd.h for Windows (Visual C)?

Try including the io.h file. It seems to be the Visual Studio's equivalent of unistd.h.

I hope this helps.

How to replace all strings to numbers contained in each string in Notepad++?

psxls gave a great answer but I think my Notepad++ version is slightly different so the $ (dollar sign) capturing did not work.

I have Notepad++ v.5.9.3 and here's how you can accomplish your task:

Search for the pattern: value=\"([0-9]*)\" And replace with: \1 (whatever you want to do around that capturing group)

Ex. Surround with square brackets

[\1] --> will produce value="[4]"

What is *.o file?

A file ending in .o is an object file. The compiler creates an object file for each source file, before linking them together, into the final executable.

Get generic type of java.util.List

Short answer: no.

This is probably a duplicate, can't find an appropriate one right now.

Java uses something called type erasure, which means at runtime both objects are equivalent. The compiler knows the lists contain integers or strings, and as such can maintain a type safe environment. This information is lost (on an object instance basis) at runtime, and the list only contain 'Objects'.

You CAN find out a little about the class, what types it might be parametrized by, but normally this is just anything that extends "Object", i.e. anything. If you define a type as

class <A extends MyClass> AClass {....}

AClass.class will only contain the fact that the parameter A is bounded by MyClass, but more than that, there's no way to tell.

How do you do natural logs (e.g. "ln()") with numpy in Python?

You could simple just do the reverse by making the base of log to e.

import math

e = 2.718281

math.log(e, 10) = 2.302585093
ln(10) = 2.30258093

Use JavaScript to place cursor at end of text in text input element

Try this one works with Vanilla JavaScript.

<input type="text" id="yourId" onfocus=" let value = this.value; this.value = null; this.value=value" name="nameYouWant" class="yourClass" value="yourValue" placeholder="yourPlaceholder...">

In Js

document.getElementById("yourId").focus()

How to resize image (Bitmap) to a given size?

Bitmap scaledBitmap = scaleDown(realImage, MAX_IMAGE_SIZE, true);

Scale down method:

public static Bitmap scaleDown(Bitmap realImage, float maxImageSize,
        boolean filter) {
    float ratio = Math.min(
            (float) maxImageSize / realImage.getWidth(),
            (float) maxImageSize / realImage.getHeight());
    int width = Math.round((float) ratio * realImage.getWidth());
    int height = Math.round((float) ratio * realImage.getHeight());

    Bitmap newBitmap = Bitmap.createScaledBitmap(realImage, width,
            height, filter);
    return newBitmap;
}

Git diff between current branch and master but not including unmerged master commits

According to Documentation

git diff Shows changes between the working tree and the index or a tree, changes between the index and a tree, changes between two trees, changes resulting from a merge, changes between two blob objects, or changes between two files on disk.

In git diff - There's a significant difference between two dots .. and 3 dots ... in the way we compare branches or pull requests in our repository. I'll give you an easy example which demonstrates it easily.

Example: Let's assume we're checking out new branch from master and pushing some code in.

  G---H---I feature (Branch)
 /
A---B---C---D master (Branch)

Two dots - If we want to show the diffs between all changes happened in the current time on both sides, We would use the git diff origin/master..feature or just git diff origin/master
,output: ( H, I against A, B, C, D )
Three dots - If we want to show the diffs between the last common ancestor (A), aka the check point we started our new branch ,we use git diff origin/master...feature,output: (H, I against A ).
I'd rather use the 3 dots in most circumstances.

How do I run a batch file from my Java Application?

The following is working fine:

String path="cmd /c start d:\\sample\\sample.bat";
Runtime rn=Runtime.getRuntime();
Process pr=rn.exec(path);

Display TIFF image in all web browser

This comes down to browser image support; it looks like the only mainstream browser that supports tiff is Safari:

http://en.wikipedia.org/wiki/Comparison_of_web_browsers#Image_format_support

Where are you getting the tiff images from? Is it possible for them to be generated in a different format?

If you have a static set of images then I'd recommend using something like PaintShop Pro to batch convert them, changing the format.

If this isn't an option then there might be some mileage in looking for a pre-written Java applet (or another browser plugin) that can display the images in the browser.

Using Cygwin to Compile a C program; Execution error

This file (cygwin1.dll) is cygwin dependency similar to qt dependency.you must copy this file and similar files that appear in such messages error, from "cygwin/bin" to folder of the your program .Also this is necessary to run in another computer that have NOT cygwin!

How to detect if a string contains special characters?

SELECT * FROM tableName WHERE columnName LIKE "%#%" OR columnName LIKE "%$%" OR (etc.)

JavaFX: How to get stage from controller during initialization?

You can get the instance of the controller from the FXMLLoader after initialization via getController(), but you need to instantiate an FXMLLoader instead of using the static methods then.

I'd pass the stage after calling load() directly to the controller afterwards:

FXMLLoader loader = new FXMLLoader(getClass().getResource("MyGui.fxml"));
Parent root = (Parent)loader.load();
MyController controller = (MyController)loader.getController();
controller.setStageAndSetupListeners(stage); // or what you want to do

Excel Calculate the date difference from today from a cell of "7/6/2012 10:26:42"

DAYS(start_date,end_date):

For example:

DAYS(A1,TODAY())

Remove HTML Tags from an NSString on the iPhone

If you want to get the content without the html tags from the web page (HTML document) , then use this code inside the UIWebViewDidfinishLoading delegate method.

  NSString *myText = [webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.textContent"];

What's the difference between "2*2" and "2**2" in Python?

To specifically answer your question Why is the code1 used if we can use code2? I might suggest that the programmer was thinking in a mathematically broader sense. Specifically, perhaps the broader equation is a power equation, and the fact that both first numbers are "2" is more coincidence than mathematical reality. I'd want to make sure that the broader context of the code supports it being

var = x * x * y

in all cases, rather than in this specific case alone. This could get you in big trouble if x is anything but 2.

Using Panel or PlaceHolder

PlaceHolder control

Use the PlaceHolder control as a container to store server controls that are dynamically added to the Web page. The PlaceHolder control does not produce any visible output and is used only as a container for other controls on the Web page. You can use the Control.Controls collection to add, insert, or remove a control in the PlaceHolder control.

Panel control

The Panel control is a container for other controls. It is especially useful when you want to generate controls programmatically, hide/show a group of controls, or localize a group of controls.

The Direction property is useful for localizing a Panel control's content to display text for languages that are written from right to left, such as Arabic or Hebrew.

The Panel control provides several properties that allow you to customize the behavior and display of its contents. Use the BackImageUrl property to display a custom image for the Panel control. Use the ScrollBars property to specify scroll bars for the control.

Small differences when rendering HTML: a PlaceHolder control will render nothing, but Panel control will render as a <div>.

More information at ASP.NET Forums

how to POST/Submit an Input Checkbox that is disabled?

You could handle it this way... For each checkbox, create a hidden field with the same name attribute. But set the value of that hidden field with some default value that you could test against. For example..

<input type="checkbox" name="myCheckbox" value="agree" />
<input type="hidden" name="myCheckbox" value="false" />

If the checkbox is "checked" when the form is submitted, then the value of that form parameter will be

"agree,false"

If the checkbox is not checked, then the value would be

"false"

You could use any value instead of "false", but you get the idea.

Using DNS to redirect to another URL with a path

Difference between string object and string literal

In the first case, there are two objects created.

In the second case, it's just one.

Although both ways str is referring to "abc".

How can I copy data from one column to another in the same table?

How about this

UPDATE table SET columnB = columnA;

This will update every row.

insert data into database using servlet and jsp in eclipse

Same problem fetch main problem in PreparedStatement use simple statement then you successfully insert record same use below.

String  st2="insert into 
user(gender,name,address,telephone,fax,email,
     destination,sdate,edate,Participant,hcategory,
     Culture,Nature,People,Cities,Beaches,Festivals,username,password) 
values('"+gender+"','"+name+"','"+address+"','"+phone+"','"+fax+"',
       '"+email+"','"+desti+"','"+sdate+"','"+edate+"','"+parti+"',
       '"+hotel+"','"+chk1+"','"+chk2+"','"+chk3+"','"+chk4+"',
       '"+chk5+"','"+chk6+"','"+user+"','"+password+"')";


int i=stm.executeUpdate(st2);

PHP code to get selected text of a combo box

if you fetching it from database then

<select id="cmbMake" name="Make" >
<option value="">Select Manufacturer</option>
<?php $s2="select * from <tablename>"; 
$q2=mysql_query($s2); 
while($rw2=mysql_fetch_array($q2)) { 
?>
<option value="<?php echo $rw2['id']; ?>"><?php echo $rw2['carname']; ?></option><?php } ?>
</select>

Does Hive have a String split function?

Just a clarification on the answer given by Bkkbrad.

I tried this suggestion and it did not work for me.

For example,

split('aa|bb','\\|')

produced:

["","a","a","|","b","b",""]

But,

split('aa|bb','[|]')

produced the desired result:

["aa","bb"]

Including the metacharacter '|' inside the square brackets causes it to be interpreted literally, as intended, rather than as a metacharacter.

For elaboration of this behaviour of regexp, see: http://www.regular-expressions.info/charclass.html

Add unique constraint to combination of two columns

Once you have removed your duplicate(s):

ALTER TABLE dbo.yourtablename
  ADD CONSTRAINT uq_yourtablename UNIQUE(column1, column2);

CREATE UNIQUE INDEX uq_yourtablename
  ON dbo.yourtablename(column1, column2);

Of course, it can often be better to check for this violation first, before just letting SQL Server try to insert the row and returning an exception (exceptions are expensive).

http://www.sqlperformance.com/2012/08/t-sql-queries/error-handling

http://www.mssqltips.com/sqlservertip/2632/checking-for-potential-constraint-violations-before-entering-sql-server-try-and-catch-logic/

If you want to prevent exceptions from bubbling up to the application, without making changes to the application, you can use an INSTEAD OF trigger:

CREATE TRIGGER dbo.BlockDuplicatesYourTable
 ON dbo.YourTable
 INSTEAD OF INSERT
AS
BEGIN
  SET NOCOUNT ON;

  IF NOT EXISTS (SELECT 1 FROM inserted AS i 
    INNER JOIN dbo.YourTable AS t
    ON i.column1 = t.column1
    AND i.column2 = t.column2
  )
  BEGIN
    INSERT dbo.YourTable(column1, column2, ...)
      SELECT column1, column2, ... FROM inserted;
  END
  ELSE
  BEGIN
    PRINT 'Did nothing.';
  END
END
GO

But if you don't tell the user they didn't perform the insert, they're going to wonder why the data isn't there and no exception was reported.

EDIT here is an example that does exactly what you're asking for, even using the same names as your question, and proves it. You should try it out before assuming the above ideas only treat one column or the other as opposed to the combination...

USE tempdb;
GO

CREATE TABLE dbo.Person
(
  ID INT IDENTITY(1,1) PRIMARY KEY,
  Name NVARCHAR(32),
  Active BIT,
  PersonNumber INT
);
GO

ALTER TABLE dbo.Person 
  ADD CONSTRAINT uq_Person UNIQUE(PersonNumber, Active);
GO

-- succeeds:
INSERT dbo.Person(Name, Active, PersonNumber)
  VALUES(N'foo', 1, 22);
GO

-- succeeds:
INSERT dbo.Person(Name, Active, PersonNumber)
  VALUES(N'foo', 0, 22);
GO

-- fails:
INSERT dbo.Person(Name, Active, PersonNumber)
  VALUES(N'foo', 1, 22);
GO

Data in the table after all of this:

ID   Name   Active PersonNumber
---- ------ ------ ------------
1    foo    1      22
2    foo    0      22

Error message on the last insert:

Msg 2627, Level 14, State 1, Line 3 Violation of UNIQUE KEY constraint 'uq_Person'. Cannot insert duplicate key in object 'dbo.Person'. The statement has been terminated.

Converting a char to ASCII?

You can use chars as is as single byte integers.

Error: Cannot pull with rebase: You have unstaged changes

Pulling with rebase is a good practice in general.

However you cannot do that if your index is not clean, i.e. you have made changes that have not been committed.

You can do this to work around, assuming you want to keep your changes:

stash your changes with: git stash
pull from master with rebase
reapply the changes you stashed in (1) with: git stash apply stash@{0} or the simpler git stash pop

Emulate a 403 error page

Use ModRewrite:

RewriteRule ^403.html$ - [F]

Just make sure you create a blank document called "403.html" in your www root or you'll get a 404 error instead of 403.

How to compile multiple java source files in command line

OR you could just use javac file1.java and then also use javac file2.java afterwards.

Summarizing multiple columns with dplyr?

The dplyr package contains summarise_all for this aim:

library(dplyr)
# summarise_all was replaced with the summarise(acrosss(..)) syntax dplyr >=1.00
df %>% group_by(grp) %>% summarise(across(everything(), list(mean)))
#> # A tibble: 3 x 5
#>     grp     a     b     c     d
#>   <int> <dbl> <dbl> <dbl> <dbl>
#> 1     1  3.08  2.98  2.98  2.91
#> 2     2  3.03  3.04  2.97  2.87
#> 3     3  2.85  2.95  2.95  3.06

Alternatively, the purrrlyr package provides the same functionality:

library(purrrlyr)
df %>% slice_rows("grp") %>% dmap(mean)
#> # A tibble: 3 x 5
#>     grp     a     b     c     d
#>   <int> <dbl> <dbl> <dbl> <dbl>
#> 1     1  3.08  2.98  2.98  2.91
#> 2     2  3.03  3.04  2.97  2.87
#> 3     3  2.85  2.95  2.95  3.06

Also don't forget about data.table (use keyby to sort sort groups):

library(data.table)
setDT(df)[, lapply(.SD, mean), keyby = grp]
#>    grp        a        b        c        d
#> 1:   1 3.079412 2.979412 2.979412 2.914706
#> 2:   2 3.029126 3.038835 2.967638 2.873786
#> 3:   3 2.854701 2.948718 2.951567 3.062678

Let's try to compare performance.

library(dplyr)
library(purrrlyr)
library(data.table)
library(bench)
set.seed(123)
n <- 10000
df <- data.frame(
  a = sample(1:5, n, replace = TRUE), 
  b = sample(1:5, n, replace = TRUE), 
  c = sample(1:5, n, replace = TRUE), 
  d = sample(1:5, n, replace = TRUE), 
  grp = sample(1:3, n, replace = TRUE)
)
dt <- setDT(df)
mark(
  dplyr = df %>% group_by(grp) %>% summarise(across(everything(), list(mean))),
  purrrlyr = df %>% slice_rows("grp") %>% dmap(mean),
  data.table = dt[, lapply(.SD, mean), keyby = grp],
  check = FALSE
)
#> # A tibble: 3 x 6
#>   expression      min   median `itr/sec` mem_alloc `gc/sec`
#>   <bch:expr> <bch:tm> <bch:tm>     <dbl> <bch:byt>    <dbl>
#> 1 dplyr        2.81ms   2.85ms      328.        NA     17.3
#> 2 purrrlyr     7.96ms   8.04ms      123.        NA     24.5
#> 3 data.table 596.33µs 707.91µs     1409.        NA     10.3

Sorting a Python list by two fields

like this:

import operator
list1 = sorted(csv1, key=operator.itemgetter(1, 2))

What is the difference between readonly="true" & readonly="readonly"?

This is a property setting rather than a valued attribute

These property settings are values per see and don't need any assignments to them. When they are present, an element has this boolean property set to true, when they're absent they're false.

<input type="text" readonly />

It's actually browsers that are liberal toward value assignment to them. If you assign any value to them it will simply get ignored. Browsers will only see the presence of a particular property and ignore the value you're trying to assign to them.

This is of course good, because some frameworks don't have the ability to add such properties without providing their value along with them. Asp.net MVC Html helpers are one of them. jQuery used to be the same until version 1.6 where they added the concept of properties.

There are of course some implications that are related to XHTML as well, because attributes in XML need values in order to be well formed. But that's a different story. Hence browsers have to ignore value assignments.

Anyway. Never mind the value you're assigning to them as long as the name is correctly spelled so it will be detected by browsers. But for readability and maintainability it's better to assign meaningful values to them like:

readonly="true" <-- arguably best human readable
readonly="readonly"

as opposed to

readonly="johndoe"
readonly="01/01/2000"

that may confuse future developers maintaining your code and may interfere with future specification that may define more strict rules to such property settings.

Pythonic way to add datetime.date and datetime.time objects

It's in the python docs.

import datetime
datetime.datetime.combine(datetime.date(2011, 1, 1), 
                          datetime.time(10, 23))

returns

datetime.datetime(2011, 1, 1, 10, 23)

How can I scroll a web page using selenium webdriver in python?

This is how you scroll down the webpage:

driver.execute_script("window.scrollTo(0, 1000);")

How can I read the contents of an URL with Python?

from urllib.request import urlopen

# if has Chinese, apply decode()
html = urlopen("https://blog.csdn.net/qq_39591494/article/details/83934260").read().decode('utf-8')
print(html)

Android: Difference between Parcelable and Serializable?

The Serializable interface can be used the same way as the Parcelable one, resulting in (not much) better performances. Just overwrite those two methods to handle manual marshalling and unmarshalling process:

private void writeObject(java.io.ObjectOutputStream out)
    throws IOException
private void readObject(java.io.ObjectInputStream in)
    throws IOException, ClassNotFoundException

Still, it seems to me that when developing native Android, using the Android api is the way to go.

See :

Having the output of a console application in Visual Studio instead of the console

I know this is just another answer, but I thought I'd write something down for the new Web Developers, who might get confused about the "Change to a Windows Application" part, because I think by default an MVC application in Visual Studio 2013 defaults to an Output Type of Class Library.

My Web Application by default is set as an output type of "Class Library." You don't have to change that. All I had to do was follow the suggestions of going to Tools > Options > Debugging > Redirect all Output Window text to the Immediate Window. I then used the System.Diagnostics.Trace suggestion by Joel Coehoorn above.

Iterate through pairs of items in a Python list

>>> a = [5, 7, 11, 4, 5]
>>> for n,k in enumerate(a[:-1]):
...     print a[n],a[n+1]
...
5 7
7 11
11 4
4 5

What is a Y-combinator?

If you're ready for a long read, Mike Vanier has a great explanation. Long story short, it allows you to implement recursion in a language that doesn't necessarily support it natively.

document.getelementbyId will return null if element is not defined?

getElementById is defined by DOM Level 1 HTML to return null in the case no element is matched.

!==null is the most explicit form of the check, and probably the best, but there is no non-null falsy value that getElementById can return - you can only get null or an always-truthy Element object. So there's no practical difference here between !==null, !=null or the looser if (document.getElementById('xx')).

Java: convert List<String> to a String

If you're using Eclipse Collections (formerly GS Collections), you can use the makeString() method.

List<String> list = Arrays.asList("Bill", "Bob", "Steve");

String string = ListAdapter.adapt(list).makeString(" and ");

Assert.assertEquals("Bill and Bob and Steve", string);

If you can convert your List to an Eclipse Collections type, then you can get rid of the adapter.

MutableList<String> list = Lists.mutable.with("Bill", "Bob", "Steve");
String string = list.makeString(" and ");

If you just want a comma separated string, you can use the version of makeString() that takes no parameters.

Assert.assertEquals(
    "Bill, Bob, Steve", 
    Lists.mutable.with("Bill", "Bob", "Steve").makeString());

Note: I am a committer for Eclipse Collections.

how to calculate percentage in python

marks = raw_input('Enter your Obtain marks:')
outof = raw_input('Enter Out of marks:')
marks = int(marks)
outof = int(outof)
per = marks*100/outof
print 'Your Percentage is:'+str(per)

Note : raw_input() function is used to take input from console and its return string formatted value. So we need to convert into integer otherwise it give error of conversion.

from unix timestamp to datetime

Looks like you might want the ISO format so that you can retain the timezone.

var dateTime = new Date(1370001284000);
dateTime.toISOString(); // Returns "2013-05-31T11:54:44.000Z"

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString

Add one year in current date PYTHON

Here's one more answer that I've found to be pretty concise and doesn't use external packages:

import datetime as dt
import calendar

# Today, in `dt.date` type
day = dt.datetime.now().date()

one_year_delta = dt.timedelta(days=366 if ((day.month >= 3 and calendar.isleap(day.year+1)) or
                                            (day.month < 3 and calendar.isleap(day.year))) else 365)

# Add one year to the current date
print(day + one_year_delta)

How to disable RecyclerView scrolling?

Extend the LayoutManager and override canScrollHorizontally()and canScrollVertically() to disable scrolling.

Be aware that inserting items at the beginning will not automatically scroll back to the beginning, to get around this do something like:

  private void clampRecyclerViewScroll(final RecyclerView recyclerView)
  {
    recyclerView.getAdapter().registerAdapterDataObserver(new RecyclerView.AdapterDataObserver()
    {
      @Override
      public void onItemRangeInserted(int positionStart, int itemCount)
      {
        super.onItemRangeInserted(positionStart, itemCount);
        // maintain scroll position at top
        if (positionStart == 0)
        {
          RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
          if (layoutManager instanceof GridLayoutManager)
          {
            ((GridLayoutManager) layoutManager).scrollToPositionWithOffset(0, 0);
          }else if(layoutManager instanceof LinearLayoutManager)
          {
            ((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(0, 0);
          }
        }
      }
    });
  }

What are the ways to sum matrix elements in MATLAB?

Another answer for the first question is to use one for loop and perform linear indexing into the array using the function NUMEL to get the total number of elements:

total = 0;
for i = 1:numel(A)
  total = total+A(i);
end

How do I programmatically get the GUID of an application in .NET 2.0

Or, just as easy:

string assyGuid = Assembly.GetExecutingAssembly().GetCustomAttribute<GuidAttribute>().Value.ToUpper();

It works for me...

PostgreSQL ERROR: canceling statement due to conflict with recovery

The table data on the hot standby slave server is modified while a long running query is running. A solution (PostgreSQL 9.1+) to make sure the table data is not modified is to suspend the replication and resume after the query:

select pg_xlog_replay_pause(); -- suspend
select * from foo; -- your query
select pg_xlog_replay_resume(); --resume

jquery stop child triggering parent event

Or, rather than having an extra event handler to prevent another handler, you can use the Event Object argument passed to your click event handler to determine whether a child was clicked. target will be the clicked element and currentTarget will be the .header div:

$(".header").click(function(e){
     //Do nothing if .header was not directly clicked
     if(e.target !== e.currentTarget) return;

     $(this).children(".children").toggle();
});

UIView bottom border?

Swift 4

Based on https://stackoverflow.com/a/32513578/5391914

import UIKit
enum ViewBorder: String {
    case Left = "borderLeft"
    case Right = "borderRight"
    case Top = "borderTop"
    case Bottom = "borderBottom"
}

extension UIView {
    
    func addBorder(vBorders: [ViewBorder], color: UIColor, width: CGFloat) {
        vBorders.forEach { vBorder in
            let border = CALayer()
            border.backgroundColor = color.cgColor
            border.name = vBorder.rawValue
            switch vBorder {
            case .Left:
                border.frame = CGRect(x: 0, y: 0, width: width, height: self.frame.size.height)
            case .Right:
                border.frame = CGRect(x:self.frame.size.width - width, y: 0, width: width, height: self.frame.size.height)
            case .Top:
                border.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: width)
            case .Bottom:
                border.frame = CGRect(x: 0, y: self.frame.size.height - width , width: self.frame.size.width, height: width)
            }
            self.layer.addSublayer(border)
        }
    }
}

What is the difference between fastcgi and fpm?

What Anthony says is absolutely correct, but I'd like to add that your experience will likely show a lot better performance and efficiency (due not to fpm-vs-fcgi but more to the implementation of your httpd).

For example, I had a quad-core machine running lighttpd + fcgi humming along nicely. I upgraded to a 16-core machine to cope with growth, and two things exploded: RAM usage, and segfaults. I found myself restarting lighttpd every 30 minutes to keep the website up.

I switched to php-fpm and nginx, and RAM usage dropped from >20GB to 2GB. Segfaults disappeared as well. After doing some research, I learned that lighttpd and fcgi don't get along well on multi-core machines under load, and also have memory leak issues in certain instances.

Is this due to php-fpm being better than fcgi? Not entirely, but how you hook into php-fpm seems to be a whole heckuva lot more efficient than how you serve via fcgi.

What does "hard coded" mean?

The antonym of Hard-Coding is Soft-Coding. For a better understanding of Hard Coding, I will introduce both terms.

Hard-coding: feature is coded to the system not allowing for configuration;
Parametric: feature is configurable via table driven, or properties files with limited parametric values ;
Soft-coding: feature uses “engines” that derive results based on any number of parametric values (e.g. business rules in BRE); rules are coded but exist as parameters in system, written in script form

Examples:

// firstName has a hard-coded value of "hello world"
string firstName = "hello world";

// firstName has a non-hard-coded provided as input
Console.WriteLine("first name :");
string firstName = Console.ReadLine();

A hard-coded constant^[1]:

float areaOfCircle(int radius)
{
    float area = 0;
    area = 3.14*radius*radius;  //  3.14 is a hard-coded value
    return area;
}

Additionally, hard-coding and soft-coding could be considered to be anti-patterns^[2]. Thus, one should strive for balance between hard and soft-coding.

Hard Coding “Hard coding” is a well-known antipattern against which most web development books warns us right in the preface. Hard coding is the unfortunate practice in which we store configuration or input data, such as a file path or a remote host name, in the source code rather than obtaining it from a configuration file, a database, a user input, or another external source.

The main problem with hard code is that it only works properly in a certain environment, and at any time the conditions change, we need to modify the source code, usually in multiple separate places.

Soft Coding
If we try very hard to avoid the pitfall of hard coding, we can easily run into another antipattern called “soft coding”, which is its exact opposite.

In soft coding, we put things that should be in the source code into external sources, for example we store business logic in the database. The most common reason why we do so, is the fear that business rules will change in the future, therefore we will need to rewrite the code.

In extreme cases, a soft coded program can become so abstract and convoluted that it is almost impossible to comprehend it (especially for new team members), and extremely hard to maintain and debug.

Sources and Citations:

1: Quora: What does hard-coded something mean in computer programming context?
2: Hongkiat: The 10 Coding Antipatterns You Must Avoid

Further Reading:

Software Engineering SE: Is it ever a good idea to hardcode values into our applications?
Wikipedia: Hardcoding
Wikipedia: Soft-coding

WPF checkbox binding

You must make your binding bidirectional :

<checkbox IsChecked="{Binding Path=MyProperty, Mode=TwoWay}"/>

fatal: 'origin' does not appear to be a git repository

I had the same error on git pull origin branchname when setting the remote origin as path fs and not ssh in .git/config:

fatal: '/path/to/repo.git' does not appear to be a git repository 
fatal: The remote end hung up unexpectedly

It was like so (this only works for users on same server of git that have access to git):

url = file:///path/to/repo.git/

Fixed it like so (this works on all users that have access to git user (ssh authorizes_keys or password)):

url = [email protected]:path/to/repo.git

the reason I had it as a directory path was because the git files are on the same server.

Wildcards in jQuery selectors

Since the title suggests wildcard you could also use this:

_x000D_

$(document).ready(function(){_x000D_
  console.log($('[id*=ander]'));_x000D_
});

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="jander1"></div>_x000D_
<div id="jander2"></div>

_x000D_

This will select the given string anywhere in the id.

Is it possible to embed animated GIFs in PDFs?

You can use Tikz/pgfplots for creating animations in beamer. http://www.texample.net/tikz/examples/tag/animations/

Switching to landscape mode in Android Emulator

Ctrl + F12 also works well on linux(ubuntu).

base64 encode in MySQL

Yet another custom implementation that doesn't require support table:

drop function if exists base64_encode;
create function base64_encode(_data blob)
returns text
begin
    declare _alphabet char(64) default 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    declare _lim int unsigned default length(_data);
    declare _i int unsigned default 0;
    declare _chk3 char(6) default '';
    declare _chk3int int default 0;
    declare _enc text default '';

    while _i < _lim do
        set _chk3 = rpad(hex(binary substr(_data, _i + 1, 3)), 6, '0');
        set _chk3int = conv(_chk3, 16, 10);
        set _enc = concat(
            _enc
            ,                  substr(_alphabet, ((_chk3int >> 18) & 63) + 1, 1)
            , if (_lim-_i > 0, substr(_alphabet, ((_chk3int >> 12) & 63) + 1, 1), '=')
            , if (_lim-_i > 1, substr(_alphabet, ((_chk3int >>  6) & 63) + 1, 1), '=')
            , if (_lim-_i > 2, substr(_alphabet, ((_chk3int >>  0) & 63) + 1, 1), '=')
        );
        set _i = _i + 3;
    end while;

    return _enc;
end;

drop function if exists base64_decode;
create function base64_decode(_enc text)
returns blob
begin
    declare _alphabet char(64) default 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    declare _lim int unsigned default 0;
    declare _i int unsigned default 0;
    declare _chr1byte tinyint default 0;
    declare _chk4int int default 0;
    declare _chk4int_bits tinyint default 0;
    declare _dec blob default '';
    declare _rem tinyint default 0;
    set _enc = trim(_enc);
    set _rem = if(right(_enc, 3) = '===', 3, if(right(_enc, 2) = '==', 2, if(right(_enc, 1) = '=', 1, 0)));
    set _lim = length(_enc) - _rem;

    while _i < _lim
    do
        set _chr1byte = locate(substr(_enc, _i + 1, 1), binary _alphabet) - 1;
        if (_chr1byte > -1)
        then
            set _chk4int = (_chk4int << 6) | _chr1byte;
            set _chk4int_bits = _chk4int_bits + 6;

            if (_chk4int_bits = 24 or _i = _lim-1)
            then
                if (_i = _lim-1 and _chk4int_bits != 24)
                then
                    set _chk4int = _chk4int << 0;
                end if;

                set _dec = concat(
                    _dec
                    ,                        char((_chk4int >> (_chk4int_bits -  8)) & 0xff)
                    , if(_chk4int_bits >  8, char((_chk4int >> (_chk4int_bits - 16)) & 0xff), '\0')
                    , if(_chk4int_bits > 16, char((_chk4int >> (_chk4int_bits - 24)) & 0xff), '\0')
                );
                set _chk4int = 0;
                set _chk4int_bits = 0;
            end if;
        end if;
        set _i = _i + 1;
    end while;

    return substr(_dec, 1, length(_dec) - _rem);
end;

Gist

You should convert charset after decoding: convert(base64_decode(base64_encode('????')) using utf8)

Fail during installation of Pillow (Python module) in Linux

The quickest fix is upgrate the pip. Did worked for me:

pip install --upgrade pip

How can I call PHP functions by JavaScript?

I created this library JS PHP Import which you can download from github, and use whenever and wherever you want.

The library allows importing php functions and class methods into javascript browser environment thus they can be accessed as javascript functions and methods by using their actual names. The code uses javascript promises so you can chain functions returns.

I hope it may useful to you.

Example:

<script>
$scandir(PATH_TO_FOLDER).then(function(result) {
  resultObj.html(result.join('<br>'));
});

$system('ls -l').then(function(result) {
  resultObj.append(result);
});

$str_replace(' ').then(function(result) {
  resultObj.append(result);
});

// Chaining functions 
$testfn(34, 56).exec(function(result) { // first call
   return $testfn(34, result); // second call with the result of the first call as a parameter
}).exec(function(result) {
   resultObj.append('result: ' + result + '<br><br>');
});
</script>

What is the difference between procedural programming and functional programming?

Procedural programming divides sequences of statements and conditional constructs into separate blocks called procedures that are parameterized over arguments that are (non-functional) values.

Functional programming is the same except that functions are first-class values, so they can be passed as arguments to other functions and returned as results from function calls.

Note that functional programming is a generalization of procedural programming in this interpretation. However, a minority interpret "functional programming" to mean side-effect-free which is quite different but irrelevant for all major functional languages except Haskell.

How to Detect Browser Back Button event - Cross Browser

I solved it by keeping track of the original event that triggered the hashchange (be it a swipe, a click or a wheel), so that the event wouldn't be mistaken for a simple landing-on-page, and using an additional flag in each of my event bindings. The browser won't set the flag again to false when hitting the back button:

var evt = null,
canGoBackToThePast = true;

$('#next-slide').on('click touch', function(e) {
    evt = e;
    canGobackToThePast = false;
    // your logic (remember to set the 'canGoBackToThePast' flag back to 'true' at the end of it)
}

Float and double datatype in Java

Floating-point numbers, also known as real numbers, are used when evaluating expressions that require fractional precision. For example, calculations such as square root, or transcendentals such as sine and cosine, result in a value whose precision requires a floating-point type. Java implements the standard (IEEE–754) set of floatingpoint types and operators. There are two kinds of floating-point types, float and double, which represent single- and double-precision numbers, respectively. Their width and ranges are shown here:

   Name     Width in Bits   Range 
    double  64              1 .7e–308 to 1.7e+308
    float   32              3 .4e–038 to 3.4e+038

float

The type float specifies a single-precision value that uses 32 bits of storage. Single precision is faster on some processors and takes half as much space as double precision, but will become imprecise when the values are either very large or very small. Variables of type float are useful when you need a fractional component, but don't require a large degree of precision.

Here are some example float variable declarations:

float hightemp, lowtemp;

double

Double precision, as denoted by the double keyword, uses 64 bits to store a value. Double precision is actually faster than single precision on some modern processors that have been optimized for high-speed mathematical calculations. All transcendental math functions, such as sin( ), cos( ), and sqrt( ), return double values. When you need to maintain accuracy over many iterative calculations, or are manipulating large-valued numbers, double is the best choice.

How do I create a chart with multiple series using different X values for each series?

You need to use the Scatter chart type instead of Line. That will allow you to define separate X values for each series.

How to redirect output to a file and stdout

Using tail -f output should work.

Entity Framework 6 GUID as primary key: Cannot insert the value NULL into column 'Id', table 'FileStore'; column does not allow nulls

You can not. You will / do break a lot of things. Like relationships. WHich rely on the number being pulled back which EF can not do in the way you set it up. THe price for breaking every pattern there is.

Generate the GUID in the C# layer, so that relationships can continue working.

How can I return pivot table output in MySQL?

This basically is a pivot table.

A nice tutorial on how to achieve this can be found here: http://www.artfulsoftware.com/infotree/qrytip.php?id=78

I advise reading this post and adapt this solution to your needs.

Update

After the link above is currently not available any longer I feel obliged to provide some additional information for all of you searching for mysql pivot answers in here. It really had a vast amount of information, and I won't put everything from there in here (even more since I just don't want to copy their vast knowledge), but I'll give some advice on how to deal with pivot tables the sql way generally with the example from peku who asked the question in the first place.

Maybe the link comes back soon, I'll keep an eye out for it.

The spreadsheet way...

Many people just use a tool like MSExcel, OpenOffice or other spreadsheet-tools for this purpose. This is a valid solution, just copy the data over there and use the tools the GUI offer to solve this.

But... this wasn't the question, and it might even lead to some disadvantages, like how to get the data into the spreadsheet, problematic scaling and so on.

The SQL way...

Given his table looks something like this:

CREATE TABLE `test_pivot` (
  `pid` bigint(20) NOT NULL AUTO_INCREMENT,
  `company_name` varchar(32) DEFAULT NULL,
  `action` varchar(16) DEFAULT NULL,
  `pagecount` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`pid`)
) ENGINE=MyISAM;

Now look into his/her desired table:

company_name    EMAIL   PRINT 1 pages   PRINT 2 pages   PRINT 3 pages
-------------------------------------------------------------
CompanyA        0       0               1               3
CompanyB        1       1               2               0

The rows (EMAIL, PRINT x pages) resemble conditions. The main grouping is by company_name.

In order to set up the conditions this rather shouts for using the CASE-statement. In order to group by something, well, use ... GROUP BY.

The basic SQL providing this pivot can look something like this:

SELECT  P.`company_name`,
    COUNT(
        CASE 
            WHEN P.`action`='EMAIL' 
            THEN 1 
            ELSE NULL 
        END
    ) AS 'EMAIL',
    COUNT(
        CASE 
            WHEN P.`action`='PRINT' AND P.`pagecount` = '1' 
            THEN P.`pagecount` 
            ELSE NULL 
        END
    ) AS 'PRINT 1 pages',
    COUNT(
        CASE 
            WHEN P.`action`='PRINT' AND P.`pagecount` = '2' 
            THEN P.`pagecount` 
            ELSE NULL 
        END
    ) AS 'PRINT 2 pages',
    COUNT(
        CASE 
            WHEN P.`action`='PRINT' AND P.`pagecount` = '3' 
            THEN P.`pagecount` 
            ELSE NULL 
        END
    ) AS 'PRINT 3 pages'
FROM    test_pivot P
GROUP BY P.`company_name`;

This should provide the desired result very fast. The major downside for this approach, the more rows you want in your pivot table, the more conditions you need to define in your SQL statement.

This can be dealt with, too, therefore people tend to use prepared statements, routines, counters and such.

Some additional links about this topic:

The property 'Id' is part of the object's key information and cannot be modified

You should add

 db.Entry(contact).State = EntityState.Detached;

After the .SaveChanges();

How to use Python's pip to download and keep the zipped files for a package?

pip install --download is deprecated. Starting from version 8.0.0 you should use pip download command:

 pip download <package-name>

jQuery `.is(":visible")` not working in Chrome

I added next style on the parent and .is(":visible") worked.

display: inline-block;

How to generate Entity Relationship (ER) Diagram of a database using Microsoft SQL Server Management Studio?

Diagrams are back as of the June 11 2019 release

Download latest

as stated:

Yes, we’ve heard the feedback; Database Diagrams is back.

SQL Server Management Studio (SSMS) 18.1 is now generally available

?? Latest Version Does Not Included It ??

Sadly, the last version of SSMS to have database diagrams as a feature was version v17.9.

Since that version, the newer preview versions starting at v18.* have, in their words "...feature has been deprecated".

Hope is not lost though, for one can still download and use v17.9 to use database diagrams which as an aside for this question is technically not a ER diagramming tool.

As of this writing it is unclear if the release version of 18 will have the feature, I hope so because it is a feature I use extensively.

Using gradle to find dependency tree

For Android, use this line

 gradle app:dependencies

or if you have a gradle wrapper:

./gradlew app:dependencies

where app is your project module.

Additionally, if you want to check if something is compile vs. testCompile vs androidTestCompile dependency as well as what is pulling it in:

./gradlew :app:dependencyInsight --configuration compile --dependency <name>
./gradlew :app:dependencyInsight --configuration testCompile --dependency <name>
./gradlew :app:dependencyInsight --configuration androidTestCompile --dependency <name>

If the application doesn't use modules, try:

gradle dependencies

List of special characters for SQL LIKE clause

ANSI SQL92:

%
_
an ESCAPE character only if specified.

It is disappointing that many databases do not stick to the standard rules and add extra characters, or incorrectly enable ESCAPE with a default value of ‘\’ when it is missing. Like we don't already have enough trouble with ‘\’!

It's impossible to write DBMS-independent code here, because you don't know what characters you're going to have to escape, and the standard says you can't escape things that don't need to be escaped. (See section 8.5/General Rules/3.a.ii.)

Thank you SQL! gnnn

How to create a HTTP server in Android?

If you are using kotlin,consider these library. It's build for kotlin language.

AndroidHttpServer is a simple demo using ServerSocket to handle http request

https://github.com/weeChanc/AndroidHttpServer

https://github.com/ktorio/ktor

AndroidHttpServer is very small , but the feature is less as well.

Ktor is a very nice library,and the usage is simple too

Retrieve column values of the selected row of a multicolumn Access listbox

Just a little addition. If you've only selected 1 row then the code below will select the value of a column (index of 4, but 5th column) for the selected row:

me.lstIssues.Column(4)

This saves having to use the ItemsSelected property.

Kristian

Disable/Enable button in Excel/VBA

The following works for me (Excel 2010)

Dim b1 As Button

Set b1 = ActiveSheet.Buttons("Button 1")

b1.Font.ColorIndex = 15
b1.Enabled = False
Application.Cursor = xlWait
Call aLongAction
b1.Enabled = True
b1.Font.ColorIndex = 1
Application.Cursor = xlDefault

Be aware that .enabled = False does not gray out a button.

The font color has to be set explicitely to get it grayed.

Build query string for System.Net.HttpClient get

To avoid double encoding issue described in taras.roshko's answer and to keep possibility to easily work with query parameters, you can use uriBuilder.Uri.ParseQueryString() instead of HttpUtility.ParseQueryString().

Javascript to sort contents of select element

This solution worked very nicely for me using jquery, thought I'd cross reference it here as I found this page before the other one. Someone else might do the same.

$("#id").html($("#id option").sort(function (a, b) {
    return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
}))

from Sorting dropdown list using Javascript

WampServer: php-win.exe The program can't start because MSVCR110.dll is missing

What solves my problem: I am using 64 bit Windows 7, so I thought I could install 64 bit Wamp. After I Installed the 32-bit version the error does not appear. So something in the developing process at Wamp went wrong...

How to define the basic HTTP authentication using cURL correctly?

curl -u username:password http://
curl -u username http://

From the documentation page:

-u, --user <user:password>

Specify the user name and password to use for server authentication. Overrides -n, --netrc and --netrc-optional.

If you simply specify the user name, curl will prompt for a password.

The user name and passwords are split up on the first colon, which makes it impossible to use a colon in the user name with this option. The password can, still.

When using Kerberos V5 with a Windows based server you should include the Windows domain name in the user name, in order for the server to succesfully obtain a Kerberos Ticket. If you don't then the initial authentication handshake may fail.

When using NTLM, the user name can be specified simply as the user name, without the domain, if there is a single domain and forest in your setup for example.

To specify the domain name use either Down-Level Logon Name or UPN (User Principal Name) formats. For example, EXAMPLE\user and [email protected] respectively.

If you use a Windows SSPI-enabled curl binary and perform Kerberos V5, Negotiate, NTLM or Digest authentication then you can tell curl to select the user name and password from your environment by specifying a single colon with this option: "-u :".

If this option is used several times, the last one will be used.

http://curl.haxx.se/docs/manpage.html#-u

Note that you do not need --basic flag as it is the default.

Find JavaScript function definition in Chrome

Lets say we're looking for function named foo:

(open Chrome dev-tools),
Windows: ctrl + shift + F, or macOS: cmd + optn + F. This opens a window for searching across all scripts.
check "Regular expression" checkbox,
search for foo\s*=\s*function (searches for foo = function with any number of spaces between those three tokens),
press on a returned result.

Another variant for function definition is function\s*foo\s*\( for function foo( with any number of spaces between those three tokens.

Windows 7 - 'make' is not recognized as an internal or external command, operable program or batch file

In Windows10, I solved this issue by adding "C:\MinGW\bin" to Path then called it using MinGW32-make not make

Implementing a Custom Error page on an ASP.Net website

Is it a spelling error in your closing tag ie:

</CustomErrors> instead of </CustomError>?

default value for struct member in C

If you only use this structure for once, i.e. create a global/static variable, you can remove typedef, and initialized this variable instantly:

struct {
    int id;
    char *name;
} employee = {
    .id = 0,
    .name = "none"
};

Then, you can use employee in your code after that.

Get all photos from Instagram which have a specific hashtag with PHP

If you only need to display the images base on a tag, then there is not to include the wrapper class "instagram.class.php". As the Media & Tag Endpoints in Instagram API do not require authentication. You can use the following curl based function to retrieve results based on your tag.

 function callInstagram($url)
    {
    $ch = curl_init();
    curl_setopt_array($ch, array(
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => 2
    ));

    $result = curl_exec($ch);
    curl_close($ch);
    return $result;
    }

    $tag = 'YOUR_TAG_HERE';
    $client_id = "YOUR_CLIENT_ID";
    $url = 'https://api.instagram.com/v1/tags/'.$tag.'/media/recent?client_id='.$client_id;

    $inst_stream = callInstagram($url);
    $results = json_decode($inst_stream, true);

    //Now parse through the $results array to display your results... 
    foreach($results['data'] as $item){
        $image_link = $item['images']['low_resolution']['url'];
        echo '<img src="'.$image_link.'" />';
    }

How does #include <bits/stdc++.h> work in C++?

#include <bits/stdc++.h> is an implementation file for a precompiled header.

From, software engineering perspective, it is a good idea to minimize the include. If you use it actually includes a lot of files, which your program may not need, thus increase both compile-time and program size unnecessarily. [edit: as pointed out by @Swordfish in the comments that the output program size remains unaffected. But still, it's good practice to include only the libraries you actually need, unless it's some competitive competition]

But in contests, using this file is a good idea, when you want to reduce the time wasted in doing chores; especially when your rank is time-sensitive.

It works in most online judges, programming contest environments, including ACM-ICPC (Sub-Regionals, Regionals, and World Finals) and many online judges.

The disadvantages of it are that it:

increases the compilation time.
uses an internal non-standard header file of the GNU C++ library, and so will not compile in MSVC, XCode, and many other compilers

How to add minutes to my Date

Once you have you date parsed, I use this utility function to add hours, minutes or seconds:

public class DateTimeUtils {
    private static final long ONE_HOUR_IN_MS = 3600000;
    private static final long ONE_MIN_IN_MS = 60000;
    private static final long ONE_SEC_IN_MS = 1000;

    public static Date sumTimeToDate(Date date, int hours, int mins, int secs) {
        long hoursToAddInMs = hours * ONE_HOUR_IN_MS;
        long minsToAddInMs = mins * ONE_MIN_IN_MS;
        long secsToAddInMs = secs * ONE_SEC_IN_MS;
        return new Date(date.getTime() + hoursToAddInMs + minsToAddInMs + secsToAddInMs);
    }
}

Be careful when adding long periods of time, 1 day is not always 24 hours (daylight savings-type adjustments, leap seconds and so on), Calendar is recommended for that.

How do I make a C++ console program exit?

Yes! exit(). It's in <cstdlib>.

Swift: Display HTML data in a label or textView

I know that this will look little over the top but ... This code will add html support to UILabel, UITextView, UIButton and you can easily add this support to any view that has attributed string support :

public protocol CSHasAttributedTextProtocol: AnyObject {
    func attributedText() -> NSAttributedString?
    func attributed(text: NSAttributedString?) -> Self
}

extension UIButton: CSHasAttributedTextProtocol {
    public func attributedText() -> NSAttributedString? {
        attributedTitle(for: .normal)
    }

    public func attributed(text: NSAttributedString?) -> Self {
        setAttributedTitle(text, for: .normal); return self
    }
}

extension UITextView: CSHasAttributedTextProtocol {
    public func attributedText() -> NSAttributedString? { attributedText }

    public func attributed(text: NSAttributedString?) -> Self { attributedText = text; return self }
}

extension UILabel: CSHasAttributedTextProtocol {
    public func attributedText() -> NSAttributedString? { attributedText }

    public func attributed(text: NSAttributedString?) -> Self { attributedText = text; return self }
}

public extension CSHasAttributedTextProtocol
        where Self: CSHasFontProtocol, Self: CSHasTextColorProtocol {
    @discardableResult
    func html(_ text: String) -> Self { html(text: text) }

    @discardableResult
    func html(text: String) -> Self {
        let html = """
                   <html><body style="color:\(textColor!.hexValue()!); 
                                font-family:\(font()!.fontName); 
                                font-size:\(font()!.pointSize);">\(text)</body></html>
                   """
        html.data(using: .unicode, allowLossyConversion: true).notNil { data in
            attributed(text: try? NSAttributedString(data: data, options: [
                .documentType: NSAttributedString.DocumentType.html,
                .characterEncoding: NSNumber(value: String.Encoding.utf8.rawValue)
            ], documentAttributes: nil))
        }
        return self
    }
}


public protocol CSHasFontProtocol: AnyObject {
    func font() -> UIFont?
    func font(_ font: UIFont?) -> Self
}

extension UIButton: CSHasFontProtocol {
    public func font() -> UIFont? { titleLabel?.font }

    public func font(_ font: UIFont?) -> Self { titleLabel?.font = font; return self }
}

extension UITextView: CSHasFontProtocol {
    public func font() -> UIFont? { font }

    public func font(_ font: UIFont?) -> Self { self.font = font; return self }
}

extension UILabel: CSHasFontProtocol {
    public func font() -> UIFont? { font }

    public func font(_ font: UIFont?) -> Self { self.font = font; return self }
}

public protocol CSHasTextColorProtocol: AnyObject {
    func textColor() -> UIColor?
    func text(color: UIColor?) -> Self
}

extension UIButton: CSHasTextColorProtocol {
    public func textColor() -> UIColor? { titleColor(for: .normal) }

    public func text(color: UIColor?) -> Self { setTitleColor(color, for: .normal); return self }
}

extension UITextView: CSHasTextColorProtocol {
    public func textColor() -> UIColor? { textColor }

    public func text(color: UIColor?) -> Self { textColor = color; return self }
}

extension UILabel: CSHasTextColorProtocol {
    public func textColor() -> UIColor? { textColor }

    public func text(color: UIColor?) -> Self { textColor = color; return self }
}

How to construct a REST API that takes an array of id's for the resources

 api.com/users?id=id1,id2,id3,id4,id5
 api.com/users?ids[]=id1&ids[]=id2&ids[]=id3&ids[]=id4&ids[]=id5

IMO, above calls does not looks RESTful, however these are quick and efficient workaround (y). But length of the URL is limited by webserver, eg tomcat.

RESTful attempt:

POST http://example.com/api/batchtask

   [
    {
      method : "GET",
      headers : [..],
      url : "/users/id1"
    },
    {
      method : "GET",
      headers : [..],
      url : "/users/id2"
    }
   ]

Server will reply URI of newly created batchtask resource.

201 Created
Location: "http://example.com/api/batchtask/1254"

Now client can fetch batch response or task progress by polling

GET http://example.com/api/batchtask/1254

This is how others attempted to solve this issue:

MySQL JOIN the most recent row only?

For anyone who must work with an older version of MySQL (pre-5.0 ish) you are unable to do sub-queries for this type of query. Here is the solution I was able to do and it seemed to work great.

SELECT MAX(d.id), d2.*, CONCAT(title,' ',forename,' ',surname) AS name
FROM customer AS c 
LEFT JOIN customer_data as d ON c.customer_id=d.customer_id 
LEFT JOIN customer_data as d2 ON d.id=d2.id
WHERE CONCAT(title, ' ', forename, ' ', surname) LIKE '%Smith%'
GROUP BY c.customer_id LIMIT 10, 20;

Essentially this is finding the max id of your data table joining it to the customer then joining the data table to the max id found. The reason for this is because selecting the max of a group doesn't guarantee that the rest of the data matches with the id unless you join it back onto itself.

I haven't tested this on newer versions of MySQL but it works on 4.0.30.

No resource found that matches the given name: attr 'android:keyboardNavigationCluster'. when updating to Support Library 26.0.0

I updated my project app/build.gradle to have

compileSDkVersion 26
buildToolsVersion '26.0.1'

However, the problem was actually with the react-native-fbsdk package. I had to change the same settings in node_modules/react-native-fbsdk/android/build.gradle.

Excel error HRESULT: 0x800A03EC while trying to get range with cell's name

Interesting enough, this error also occurs, at time of opening when the .XLS? file is incorrectly formed or require repairs.

A hard to find error is to many rows on a .xls (old excel) file.

Test it: manually open the affected file with excel desktop .

I use automation to process a few hundred files daily, when this error show up, I notify the owner via mail and save the unprocessed file on a temporary location.

What is the method for converting radians to degrees?

a complete circle in radians is 2*pi. A complete circle in degrees is 360. To go from degrees to radians, it's (d/360) * 2*pi, or d*pi/180.

Extract Data from PDF and Add to Worksheet

Since I do not prefer to rely on external libraries and/or other programs, I have extended your solution so that it works. The actual change here is using the GetFromClipboard function instead of Paste which is mainly used to paste a range of cells. Of course, the downside is that the user must not change focus or intervene during the whole process.

Dim pathPDF As String, textPDF As String
Dim openPDF As Object
Dim objPDF As MsForms.DataObject

pathPDF = "C:\some\path\data.pdf"
Set openPDF = CreateObject("Shell.Application")
openPDF.Open (pathPDF)
'TIME TO WAIT BEFORE/AFTER COPY AND PASTE SENDKEYS
Application.Wait Now + TimeValue("00:00:2")
SendKeys "^a"
Application.Wait Now + TimeValue("00:00:2")
SendKeys "^c"
Application.Wait Now + TimeValue("00:00:1")

AppActivate ActiveWorkbook.Windows(1).Caption
objPDF.GetFromClipboard
textPDF = objPDF.GetText(1)
MsgBox textPDF

If you're interested see my project in github.

How do I break out of nested loops in Java?

Like @1800 INFORMATION suggestion, use the condition that breaks the inner loop as a condition on the outer loop:

boolean hasAccess = false;
for (int i = 0; i < x && hasAccess == false; i++){
    for (int j = 0; j < y; j++){
        if (condition == true){
            hasAccess = true;
            break;
        }
    }
}

ASP.NET - How to write some html in the page? With Response.Write?

You should really use the Literal ASP.NET control for that.

iterating through json object javascript

Here is my recursive approach:

function visit(object) {
    if (isIterable(object)) {
        forEachIn(object, function (accessor, child) {
            visit(child);
        });
    }
    else {
        var value = object;
        console.log(value);
    }
}

function forEachIn(iterable, functionRef) {
    for (var accessor in iterable) {
        functionRef(accessor, iterable[accessor]);
    }
}

function isIterable(element) {
    return isArray(element) || isObject(element);
}

function isArray(element) {
    return element.constructor == Array;
}

function isObject(element) {
    return element.constructor == Object;
}

How can I convert a string to a float in mysql?

It turns out I was just missing DECIMAL on the CAST() description:

DECIMAL[(M[,D])]

Converts a value to DECIMAL data type. The optional arguments M and D specify the precision (M specifies the total number of digits) and the scale (D specifies the number of digits after the decimal point) of the decimal value. The default precision is two digits after the decimal point.

Thus, the following query worked:

UPDATE table SET
latitude = CAST(old_latitude AS DECIMAL(10,6)),
longitude = CAST(old_longitude AS DECIMAL(10,6));

How to force Chrome browser to reload .css file while debugging in Visual Studio?

Just had this problem where one person running Chrome (on a Mac) suddenly stopped loading the CSS file. CMD + R did NOT work at all. I don't like the suggestions above that force a permanent reload on the production system.

What worked was changing the name of the CSS file in the HTML file (and renaming the CSS file of course). This forced Chrome to go get the latest CSS file.

How do I change the background color of a plot made with ggplot2

To avoid deprecated opts and theme_rect use:

myplot + theme(panel.background = element_rect(fill='green', colour='red'))

To define your own custom theme, based on theme_gray but with some of your changes and a few added extras including control of gridline colour/size (more options available to play with at ggplot2.org):

theme_jack <- function (base_size = 12, base_family = "") {
    theme_gray(base_size = base_size, base_family = base_family) %+replace% 
        theme(
            axis.text = element_text(colour = "white"),
            axis.title.x = element_text(colour = "pink", size=rel(3)),
            axis.title.y = element_text(colour = "blue", angle=45),
            panel.background = element_rect(fill="green"),
            panel.grid.minor.y = element_line(size=3),
            panel.grid.major = element_line(colour = "orange"),
            plot.background = element_rect(fill="red")
    )   
}

To make your custom theme the default when ggplot is called in future, without masking:

theme_set(theme_jack())

If you want to change an element of the currently set theme:

theme_update(plot.background = element_rect(fill="pink"), axis.title.x = element_text(colour = "red"))

To store the current default theme as an object:

theme_pink <- theme_get()

Note that theme_pink is a list whereas theme_jack was a function. So to return the theme to theme_jack use theme_set(theme_jack()) whereas to return to theme_pink use theme_set(theme_pink).

You can replace theme_gray by theme_bw in the definition of theme_jack if you prefer. For your custom theme to resemble theme_bw but with all gridlines (x, y, major and minor) turned off:

theme_nogrid <- function (base_size = 12, base_family = "") {
    theme_bw(base_size = base_size, base_family = base_family) %+replace% 
        theme(
            panel.grid = element_blank()
    )   
}

Finally a more radical theme useful when plotting choropleths or other maps in ggplot, based on discussion here but updated to avoid deprecation. The aim here is to remove the gray background, and any other features that might distract from the map.

theme_map <- function (base_size = 12, base_family = "") {
    theme_gray(base_size = base_size, base_family = base_family) %+replace% 
        theme(
            axis.line=element_blank(),
            axis.text.x=element_blank(),
            axis.text.y=element_blank(),
            axis.ticks=element_blank(),
            axis.ticks.length=unit(0.3, "lines"),
            axis.ticks.margin=unit(0.5, "lines"),
            axis.title.x=element_blank(),
            axis.title.y=element_blank(),
            legend.background=element_rect(fill="white", colour=NA),
            legend.key=element_rect(colour="white"),
            legend.key.size=unit(1.2, "lines"),
            legend.position="right",
            legend.text=element_text(size=rel(0.8)),
            legend.title=element_text(size=rel(0.8), face="bold", hjust=0),
            panel.background=element_blank(),
            panel.border=element_blank(),
            panel.grid.major=element_blank(),
            panel.grid.minor=element_blank(),
            panel.margin=unit(0, "lines"),
            plot.background=element_blank(),
            plot.margin=unit(c(1, 1, 0.5, 0.5), "lines"),
            plot.title=element_text(size=rel(1.2)),
            strip.background=element_rect(fill="grey90", colour="grey50"),
            strip.text.x=element_text(size=rel(0.8)),
            strip.text.y=element_text(size=rel(0.8), angle=-90) 
        )   
}

best way to get the key of a key/value javascript object

use for each loop for accessing keys in Object or Maps in javascript

for(key in foo){
   console.log(key);//for key name in your case it will be bar
   console.log(foo[key]);// for key value in your case it will be baz
}

Note: you can also use

Object.keys(foo);

it will give you like this output:

[bar];

Why does my sorting loop seem to append an element where it shouldn't?

Starting from Java 8, you can also use parallelSort which is useful if you have arrays containing a lot of elements.

Example:

public static void main(String[] args) {
    String[] strings = { "x", "a", "c", "b", "y" };
    Arrays.parallelSort(strings);
    System.out.println(Arrays.toString(strings));   // [a, b, c, x, y]
}

If you want to ignore the case, you can use:

public static void main(String[] args) {
    String[] strings = { "x", "a", "c", "B", "y" };
    Arrays.parallelSort(strings, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {              
            return o1.compareToIgnoreCase(o2);
        }
    });
    System.out.println(Arrays.toString(strings));   // [a, B, c, x, y]
}

otherwise B will be before a.

If you want to ignore the trailing spaces during the comparison, you can use trim():

public static void main(String[] args) {
    String[] strings = { "x", "  a", "c ", " b", "y" };
    Arrays.parallelSort(strings, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {              
            return o1.trim().compareTo(o2.trim());
        }
    });
    System.out.println(Arrays.toString(strings)); // [  a,  b, c , x, y]
}

See:

How to use a ViewBag to create a dropdownlist?

@Html.DropDownListFor(m => m.Departments.id, (SelectList)ViewBag.Department, "Select", htmlAttributes: new { @class = "form-control" })

Creating files in C++

use c methods FILE *fp =fopen("filename","mode"); fclose(fp); mode means a for appending r for reading ,w for writing

   / / using ofstream constructors.
      #include <iostream>
       #include <fstream>  
      std::string input="some text to write"
     std::ofstream outfile ("test.txt");

    outfile <<input << std::endl;

       outfile.close();

How to determine if a String has non-alphanumeric characters?

You can use isLetter(char c) static method of Character class in Java.lang .

public boolean isAlpha(String s) {
    char[] charArr = s.toCharArray();

    for(char c : charArr) {
        if(!Character.isLetter(c)) {
            return false;
        }
    }
    return true;
}

C++ obtaining milliseconds time on Linux -- clock() doesn't seem to work properly

clock() doesn't return milliseconds or seconds on linux. Usually clock() returns microseconds on a linux system. The proper way to interpret the value returned by clock() is to divide it by CLOCKS_PER_SEC to figure out how much time has passed.

When do I need to use AtomicBoolean in Java?

The AtomicBoolean class gives you a boolean value that you can update atomically. Use it when you have multiple threads accessing a boolean variable.

The java.util.concurrent.atomic package overview gives you a good high-level description of what the classes in this package do and when to use them. I'd also recommend the book Java Concurrency in Practice by Brian Goetz.

Bash Shell Script - Check for a flag and grab its value

Try shFlags -- Advanced command-line flag library for Unix shell scripts.

http://code.google.com/p/shflags/

It is very good and very flexible.

FLAG TYPES: This is a list of the DEFINE_*'s that you can do. All flags take a name, default value, help-string, and optional 'short' name (one-letter name). Some flags have other arguments, which are described with the flag.

DEFINE_string: takes any input, and intreprets it as a string.

DEFINE_boolean: typically does not take any argument: say --myflag to set FLAGS_myflag to true, or --nomyflag to set FLAGS_myflag to false. Alternately, you can say --myflag=true or --myflag=t or --myflag=0 or --myflag=false or --myflag=f or --myflag=1 Passing an option has the same affect as passing the option once.

DEFINE_float: takes an input and intreprets it as a floating point number. As shell does not support floats per-se, the input is merely validated as being a valid floating point value.

DEFINE_integer: takes an input and intreprets it as an integer.

SPECIAL FLAGS: There are a few flags that have special meaning: --help (or -?) prints a list of all the flags in a human-readable fashion --flagfile=foo read flags from foo. (not implemented yet) -- as in getopt(), terminates flag-processing

EXAMPLE USAGE:

-- begin hello.sh --
 ! /bin/sh
. ./shflags
DEFINE_string name 'world' "somebody's name" n
FLAGS "$@" || exit $?
eval set -- "${FLAGS_ARGV}"
echo "Hello, ${FLAGS_name}."
-- end hello.sh --

$ ./hello.sh -n Kate
Hello, Kate.

Note: I took this text from shflags documentation

Error: 0xC0202009 at Data Flow Task, OLE DB Destination [43]: SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80040E21

So this error is occurring because you have a value in your source for the AppID column that is not valid for your AppID column in the destination.

Some possible examples:

You're trying to insert a 10 character value into an 8 character field.
You're trying to insert a value larger than 127 into a tinyint field.
You're trying to insert the value 6.4578 into a decimal(5,1) field.

SSIS is governed by metadata, and it expects that you've set up your inputs and outputs properly such that the acceptable values for both are within the same range.

What type of hash does WordPress use?

MD5 worked for me changing my database manually. See: Resetting Your Password

docker command not found even though installed with apt-get

The Ubuntu package docker actually refers to a GUI application, not the beloved DevOps tool we've come out to look for.

The instructions for docker can be followed per instructions on the docker page here: https://docs.docker.com/engine/install/ubuntu/

=== UPDATED (thanks @Scott Stensland) ===

You now run the following install script to get docker:

`sudo curl -sSL https://get.docker.com/ | sh`

Note: review the script on the website and make sure you have the right link before continuing since you are running this as sudo.

This will run a script that installs docker. Note the last part of the script:

If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:

  `sudo usermod -aG docker stens`

Remember that you will have to log out and back in for this to take effect!

To update Docker run:

`sudo apt-get update && sudo apt-get upgrade`

For more details on what's going on, See the docker install documentation or @Scott Stensland's answer below

=== UPDATE: For those uncomfortable w/ sudo | sh ===

Some in the comments have mentioned that it a risk to run an arbitrary script as sudo. The above option is a convenience script from docker to make the task simple. However, for those that are security-focused but don't want to read the script you can do the following:

Add Dependencies

sudo apt-get update; \
sudo apt-get install \
 apt-transport-https \
 ca-certificates \
 curl \
 gnupg-agent \
 software-properties-common

Add docker gpg key

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

(Security check, verify key fingerprint 9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88

$ sudo apt-key fingerprint 0EBFCD88

pub   rsa4096 2017-02-22 [SCEA]
      9DC8 5822 9FC7 DD38 854A  E2D8 8D81 803C 0EBF CD88
uid           [ unknown] Docker Release (CE deb) <[email protected]>
sub   rsa4096 2017-02-22 [S]

)

Setup Repository

sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

Install Docker

sudo apt-get update; \
sudo apt-get install docker-ce docker-ce-cli containerd.io

If you want to verify that it worked run: sudo docker run hello-world

The following explains why it is named like this: Why install docker on ubuntu should be `sudo apt-get install docker.io`?

jQuery count number of divs with a certain class?

For better performance you should use:

var numItems = $('div.item').length;

Since it will only look for the div elements in DOM and will be quick.

Suggestion: using size() instead of length property means one extra step in the processing since SIZE() uses length property in the function definition and returns the result.

How to change XML Attribute

If the attribute you want to change doesn't exist or has been accidentally removed, then an exception occurs. I suggest you first create a new attribute and send it to a function like the following:

private void SetAttrSafe(XmlNode node,params XmlAttribute[] attrList)
    {
        foreach (var attr in attrList)
        {
            if (node.Attributes[attr.Name] != null)
            {
                node.Attributes[attr.Name].Value = attr.Value;
            }
            else
            {
                node.Attributes.Append(attr);
            }
        }
    }

Usage:

   XmlAttribute attr = dom.CreateAttribute("name");
   attr.Value = value;
   SetAttrSafe(node, attr);

Big-O summary for Java Collections Framework implementations?

The Javadocs from Sun for each collection class will generally tell you exactly what you want. HashMap, for example:

This implementation provides constant-time performance for the basic operations (get and put), assuming the hash function disperses the elements properly among the buckets. Iteration over collection views requires time proportional to the "capacity" of the HashMap instance (the number of buckets) plus its size (the number of key-value mappings).

TreeMap:

This implementation provides guaranteed log(n) time cost for the containsKey, get, put and remove operations.

TreeSet:

This implementation provides guaranteed log(n) time cost for the basic operations (add, remove and contains).

(emphasis mine)

What is the difference between cssSelector & Xpath and which is better with respect to performance for cross browser testing?

CSS selectors perform far better than Xpath and it is well documented in Selenium community. Here are some reasons,

Xpath engines are different in each browser, hence make them inconsistent
IE does not have a native xpath engine, therefore selenium injects its own xpath engine for compatibility of its API. Hence we lose the advantage of using native browser features that WebDriver inherently promotes.
Xpath tend to become complex and hence make hard to read in my opinion

However there are some situations where, you need to use xpath, for example, searching for a parent element or searching element by its text (I wouldn't recommend the later).

You can read blog from Simon here . He also recommends CSS over Xpath.

If you are testing content then do not use selectors that are dependent on the content of the elements. That will be a maintenance nightmare for every locale. Try talking with developers and use techniques that they used to externalize the text in the application, like dictionaries or resource bundles etc. Here is my blog that explains it in detail.

edit 1

Thanks to @parishodak, here is the link which provides the numbers proving that CSS performance is better

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

To answer TJJ: But is it also possible to do this without copying the whole file? So, just to somehow create an additional vmdk-metafile, that references the raw dd-image.

Yes, it's possible. Here's how to use a flat disk image in VirtualBox:

First you create an image with dd in the usual way:

dd bs=512 count=60000 if=/dev/zero of=usbdrv.img

Then you can create a file for VirtualBox that references this image:

VBoxManage internalcommands createrawvmdk -filename "usbdrv.vmdk" -rawdisk "usbdrv.img"

You can use this image in VirtualBox as is, but depending on the guest OS it might not be visible immediately. For example, I experimented on using this method with a Windows guest OS and I had to do the following to give it a drive letter:

Go to the Control Panel.
Go to Administrative Tools.
Go to Computer Management.
Go to Storage\Disk Management in the left side panel.
You'll see your disk here. Create a partition on it and format it. Use FAT for small volumes, FAT32 or NTFS for large volumes.

You might want to access your files on Linux. First dismount it from the guest OS to be sure and remove it from the virtual machine. Now we need to create a virtual device that references the partition.

sfdisk -d usbdrv.img

Response:

label: dos
label-id: 0xd367a714
device: usbdrv.img
unit: sectors

usbdrv.img1 : start=          63, size=       48132, type=4

Take note of the start position of the partition: 63. In the command below I used loop4 because it was the first available loop device in my case.

sudo losetup -o $((63*512)) loop4 usbdrv.img
mkdir usbdrv
sudo mount /dev/loop4 usbdrv
ls usbdrv -l

Response:

total 0
-rwxr-xr-x. 1 root root 0 Apr  5 17:13 'Test file.txt'

Yay!

What is the best collation to use for MySQL with PHP?

Collations affect how data is sorted and how strings are compared to each other. That means you should use the collation that most of your users expect.

Example from the documentation for charset unicode:

utf8_general_ci also is satisfactory for both German and French, except that ‘ß’ is equal to ‘s’, and not to ‘ss’. If this is acceptable for your application, then you should use utf8_general_ci because it is faster. Otherwise, use utf8_unicode_ci because it is more accurate.

So - it depends on your expected user base and on how much you need correct sorting. For an English user base, utf8_general_ci should suffice, for other languages, like Swedish, special collations have been created.

How to Convert an int to a String?

Did you try:

text_Rate.setText(String.valueOf(sdRate));

Flutter: Trying to bottom-center an item in a Column, but it keeps left-aligning

Expanded(
  child: Align(
    alignment: FractionalOffset.bottomCenter,
      child: Padding(
        padding: EdgeInsets.only(bottom: 10.0),
          child: //Your widget here,
    ),
  ),
),

Psql could not connect to server: No such file or directory, 5432 error?

I recommend you should clarify port that postgres. In my case I didn't know which port postgres was running on.

lsof -i | grep 'post'

then you can know which port is listening.

psql -U postgres -p "port_in_use"

with port option, might be answer. you can use psql.

No mapping found for HTTP request with URI.... in DispatcherServlet with name

Check ur Bean xmlns..

I also had similar problem, but I resolved it by adding mvc xmlns.

<?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:mvc="http://www.springframework.org/schema/mvc" 
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.2.xsd 
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">


    <context:component-scan base-package="net.viralpatel.spring3.controller" />
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

Error CS1705: "which has a higher version than referenced assembly"

My team just ran into this problem within our build environment. The issue was due to a difference in the <HintPath> element of the .csproj file.

Our common assembly had a correct relative path to the directory containing our reference assemblies. The dependent assembly had a path from a former directory structure. The solution successfully compiled on dev machines as the GAC resolved the dependent's reference to the correct version installed in C:\Program Files. The build environment had a legacy install of the assembly (even though it should have had none) that it fell back to and thus the error. Updating the <HintPath> in a text editor corrected the problem.

jQuery selector first td of each row

try this selector -

$("tr").find("td:first")

Demo --> http://jsfiddle.net/66HbV/

$("tr td:first-child")

Demo --> http://jsfiddle.net/66HbV/1/

</td>foobar</td> should be <td>foobar</td>

Filter Excel pivot table using VBA

In Excel 2007 onwards, you can use the much simpler code using a more precise reference:

dim pvt as PivotTable
dim pvtField as PivotField

set pvt = ActiveSheet.PivotTables("PivotTable2")
set pvtField = pvt.PivotFields("SavedFamilyCode")

pvtField.PivotFilters.Add xlCaptionEquals, Value1:= "K123223"

How to format font style and color in echo

You should also use the style 'color' and not 'font-color'

<?php

foreach($months as $key => $month){
  if(strpos($filename,$month)!==false){
        echo "<style = 'color: #ff0000;'> Movie List for {$key} 2013 </style>";
    }
}

?>

In general, the comments on double and single quotes are correct in other suggestions. $Variables only execute in double quotes.

Can't find bundle for base name /Bundle, locale en_US

The exception is telling that a Bundle_en_US.properties, or Bundle_en.properties, or at least Bundle.properties file is expected in the root of the classpath, but there is actually none.

Make sure that at least one of the mentioned files is present in the root of the classpath. Or, make sure that you provide the proper bundle name. For example, if the bundle files are actually been placed in the package com.example.i18n, then you need to pass com.example.i18n.Bundle as bundle name instead of Bundle.

In case you're using Eclipse "Dynamic Web Project", the classpath root is represented by src folder, there where all your Java packages are. In case you're using a Maven project, the classpath root for resource files is represented by src/main/resources folder.

How to fill in form field, and submit, using javascript?

document.getElementById('username').value="moo"
document.forms[0].submit()

How to Change color of Button in Android when Clicked?

If you want to change the backgorund image or color of the button when it is pressed, then just copy this code and paste in your project at exact location described below.

      <!-- Create new xml file like mybtn_layout.xml file in drawable -->
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:drawable="@drawable/pressed" /> <!--pressed --> 
<item android:drawable="@drawable/normal" /> <!-- Normal -->
</selector>
  <!-- Now this file should be in a drawable folder and use this 
  single line code in    button code to get all the properties of this xml file -->

    <Button
      android:id="@+id/street_btn"
      android:layout_width="wrap_content"
      android:background="@drawable/layout_a" > <!-- your required code -->
    </Button>

How to clean old dependencies from maven repositories?

Download all actual dependencies of your projects

find your-projects-dir -name pom.xml -exec mvn -f '{}' dependency:resolve

Move your local maven repository to temporary location
```
mv ~/.m2 ~/saved-m2
```

Rename all files maven-metadata-central.xml* from saved repository into maven-metadata.xml*

find . -type f -name "maven-metadata-central.xml*" -exec rename -v -- 's/-central//' '{}' \;

To setup the modified copy of the local repository as a mirror, create the directory ~/.m2 and the file ~/.m2/settings.xml with the following content (replacing user with your username):

<settings>
 <mirrors>
  <mirror>
   <id>mycentral</id>
   <name>My Central</name>
   <url>file:/home/user/saved-m2/</url>
   <mirrorOf>central</mirrorOf>
  </mirror>
 </mirrors>
</settings>

Resolve your projects dependencies again:

find your-projects-dir -name pom.xml -exec mvn -f '{}' dependency:resolve

Now you have local maven repository with minimal of necessary artifacts. Remove local mirror from config file and from file system.

How to get to Model or Viewbag Variables in a Script Tag

You can do this way, providing Json or Any other variable:

1) For exemple, in the controller, you can use Json.NET to provide Json to the ViewBag:

ViewBag.Number = 10;
ViewBag.FooObj = JsonConvert.SerializeObject(new Foo { Text = "Im a foo." });

2) In the View, put the script like this at the bottom of the page.

<script type="text/javascript">
    var number = parseInt(@ViewBag.Number); //Accessing the number from the ViewBag
    alert("Number is: " + number);
    var model = @Html.Raw(@ViewBag.FooObj); //Accessing the Json Object from ViewBag
    alert("Text is: " + model.Text);
</script>

get the value of "onclick" with jQuery?

$('#google').attr('onclick') + ""

However, Firebug shows that this returns a function 'onclick'. You can call the function later on using the following approach:

(new Function ($('#google').attr('onclick') + ';onclick();'))()

... or use a RegEx to strip the function and get only the statements within it.

How to get the current time in YYYY-MM-DD HH:MI:Sec.Millisecond format in Java?

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");

SQL query for extracting year from a date

How about this one?

SELECT TO_CHAR(ASOFDATE, 'YYYY') FROM PSASOFDATE

Sublime Text 2 Code Formatting

A similar option in Sublime Text is the built in Edit->Line->Reindent. You can put this code in Preferences -> Key Bindings User:

{ "keys": ["alt+shift+f"], "command": "reindent"}

I use alt+shift+f because I'm a Netbeans user.

To format your code, select all by pressing ctrl+a and "your key combination". Excuse me for my bad english.

Or if you don't want to select all before formatting, add an argument to the command instead:

{ "keys": ["alt+shift+f"], "command": "reindent", "args": {"single_line": false} }

(as per comment by @Supr below)

How to update Ruby with Homebrew?

brew upgrade ruby

Should pull latest version of the package and install it.

brew update updates brew itself, not packages (formulas they call it)

Assigning strings to arrays of characters

You can use this:

yylval.sval=strdup("VHDL + Volcal trance...");

Where yylval is char*. strdup from does the job.

Cannot find or open the PDB file in Visual Studio C++ 2010

you just add the path of .pdb to work directory of VS!

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

I have been looking at the answers all impressive. I think He should provide the code that is giving him a problem. Given the example below, If you have a script to link to jquery in page.php then you get that notice.

$().ready(function () {
    $.ajax({url: "page.php",
        type: 'GET',
        success: function (result) {
        $("#page").html(result);
   }});
 });

align 3 images in same row with equal spaces?

I assumed the first DIV is #content :

<div id="content">
   <img src="@Url.Content("~/images/image1.bmp")" alt="" />
   <img src="@Url.Content("~/images/image2.bmp")" alt="" />
   <img src="@Url.Content("~/images/image3.bmp")" alt="" />
</div>

And CSS :

#content{
         width: 700px;
         display: block;
         height: auto;
     }
     #content > img{
        float: left; width: 200px;
        height: 200px;
        margin: 5px 8px;
     }

Android center view in FrameLayout doesn't work

Set 'center_horizontal' and 'center_vertical' or just 'center' of the layout_gravity attribute of the widget

    <?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MovieActivity"
    android:id="@+id/mainContainerMovie"
    >


    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#3a3f51b5"
       />

    <ProgressBar
        android:id="@+id/movieprogressbar"
        style="?android:attr/progressBarStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical|center_horizontal" />
</FrameLayout>

SQL is null and = null

It's important to note, that NULL doesn't equal NULL.

NULL is not a value, and therefore cannot be compared to another value.

where x is null checks whether x is a null value.

where x = null is checking whether x equals NULL, which will never be true

Disable html5 video autoplay

You can set autoplay=""

<video width="640" height="480" controls="controls" type="video/mp4" autoplay="">
<source src="http://example.com/mytestfile.mp4">
Your browser does not support the video tag.
</video>

ps. for enabling you can use autoplay or autoplay="autoplay"

how to destroy bootstrap modal window completely?

This completely removes the modal from the DOM , is working for the "appended" modals as well .

#pickoptionmodal is the id of my modal window.

$(document).on('hidden.bs.modal','#pickoptionmodal',function(e){

e.preventDefault();

$("#pickoptionmodal").remove();

});

How to show empty data message in Datatables

Late to the game, but you can also use a localisation file

DataTable provides a .json localized file, which contains the key sEmptyTable and the corresponding localized message.

For example, just download the localized json file on the above link, then initialize your Datatable like that :

$('#example').dataTable( {
    "language": {
        "url": "path/to/your/json/file.json"
    }
});

IMHO, that's a lot cleaner, because your localized content is located in an external file.

This syntax works for DataTables 1.10.16, I didn't test on previous versions.

How to fix 'android.os.NetworkOnMainThreadException'?

You are not allowed to implement network operations on the UI thread on Android. You will have to use AsyncTask class to perform network related operations like sending API request, downloading image from a URL, etc. and using callback methods of AsyncTask, you can get you result in onPostExecute menthod and you will be in the UI thread and you can populate UI with data from web service or something like that.

Example: Suppose you want to download image from an URL: https://www.samplewebsite.com/sampleimage.jpg

Solution using AsyncTask: are respectively.

    public class MyDownloader extends AsyncTask<String,Void,Bitmap>
    {
        @Override
        protected void onPreExecute() {
            // Show progress dialog
            super.onPreExecute();
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            //Populate Ui
            super.onPostExecute(bitmap);
        }

        @Override
        protected Bitmap doInBackground(String... params) {
            // Open URL connection read bitmaps and return form here
            return result;
        }

        @Override
        protected void onProgressUpdate(Void... values) {
            // Show progress update
            super.onProgressUpdate(values);
        }


    }
}

Note: Do not forget to add the Internet permission in the Android manifest file. It will work like a charm. :)

Java, How to add library files in netbeans?

How to import a commons-library into netbeans.

Evaluate the error message in NetBeans:

java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory

NoClassDeffFoundError means somewhere under the hood in the code you used, a method called another method which invoked a class that cannot be found. So what that means is your code did this: MyFoobarClass foobar = new MyFoobarClass() and the compiler is confused because nowhere is defined this MyFoobarClass. This is why you get an error.
To know what to do next, you have to look at the error message closely. The words 'org/apache/commons' lets you know that this is the codebase that provides the tools you need. You have a choice, either you can import EVERYTHING in apache commons, or you could import JUST the LogFactory class, or you could do something in between. Like for example just get the logging bit of apache commons.
You'll want to go the middle of the road and get commons-logging. Excellent choice, fire up the google and search for apache commons-logging. The first link takes you to http://commons.apache.org/proper/commons-logging/. Go to downloads. There you will find the most up-to-date ones. If your project was compiled under ancient versions of commons-logging, then use those same ancient ones because if you use the newer ones, the code may fail because the newer versions are different.
You're going to want to download the commons-logging-1.1.3-bin.zip or something to that effect. Read what the name is saying. The .zip means it's a compressed file. commons-logging means that this one should contain the LogFactory class you desire. the middle 1.1.3 means that is the version. if you are compiling for an old version, you'll need to match these up, or else you risk the code not compiling right due to changes due to upgrading.
Download that zip. Unzip it. Search around for things that end in .jar. In netbeans right click your project, click properties, click libraries, click "add jar/folder" and import those jars. Save the project, and re-run, and the errors should be gone.

The binaries don't include the source code, so you won't be able to drill down and see what is happening when you debug. As programmers you should be downloading "the source" of apache commons and compiling from source, generating the jars yourself and importing those for experience. You should be smart enough to understand and correct the source code you are importing. These ancient versions of apache commons might have been compiled under an older version of Java, so if you go too far back, they may not even compile unless you compile them under an ancient version of java.

DataGridView.Clear()

all you need to do is clear your datatable before you fill it... and then just set it as you dgv's datasource

How do I create a WPF Rounded Corner container?

I just had to do this myself, so I thought I would post another answer here.

Here is another way to create a rounded corner border and clip its inner content. This is the straightforward way by using the Clip property. It's nice if you want to avoid a VisualBrush.

The xaml:

<Border
    Width="200"
    Height="25"
    CornerRadius="11"
    Background="#FF919194"
>
    <Border.Clip>
        <RectangleGeometry
            RadiusX="{Binding CornerRadius.TopLeft, RelativeSource={RelativeSource AncestorType={x:Type Border}}}"
            RadiusY="{Binding RadiusX, RelativeSource={RelativeSource Self}}"
        >
            <RectangleGeometry.Rect>
                <MultiBinding
                    Converter="{StaticResource widthAndHeightToRectConverter}"
                >
                    <Binding
                        Path="ActualWidth"
                        RelativeSource="{RelativeSource AncestorType={x:Type Border}}"
                    />
                    <Binding
                        Path="ActualHeight"
                        RelativeSource="{RelativeSource AncestorType={x:Type Border}}"
                    />
                </MultiBinding>
            </RectangleGeometry.Rect>
        </RectangleGeometry>
    </Border.Clip>

    <Rectangle
        Width="100"
        Height="100"
        Fill="Blue"
        HorizontalAlignment="Left"
        VerticalAlignment="Center"
    />
</Border>

The code for the converter:

public class WidthAndHeightToRectConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        double width = (double)values[0];
        double height = (double)values[1];
        return new Rect(0, 0, width, height);
    }
    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

How to grep with a list of words

You need to use the option -f:

$ grep -f A B

The option -F does a fixed string search where as -f is for specifying a file of patterns. You may want both if the file only contains fixed strings and not regexps.

$ grep -Ff A B

You may also want the -w option for matching whole words only:

$ grep -wFf A B

Read man grep for a description of all the possible arguments and what they do.

How to calculate md5 hash of a file using javascript

Apart from the impossibility to get file system access in JS, I would not put any trust at all in a client-generated checksum. So generating the checksum on the server is mandatory in any case. – Tomalak Apr 20 '09 at 14:05

Which is useless in most cases. You want the MD5 computed at client side, so that you can compare it with the code recomputed at server side and conclude the upload went wrong if they differ. I have needed to do that in applications working with large files of scientific data, where receiving uncorrupted files were key. My cases was simple, cause users had the MD5 already computed from their data analysis tools, so I just needed to ask it to them with a text field.

Reporting Services permissions on SQL Server R2 SSRS

in my case this error resolved by adding permission level to root folder .

i previously only granted permission in 2 place. one in site setting and one in a new folder that has custom permission .

but the user permission to browse the root folder was also required. Note The "Folder setting" in root folder

another time i had similar problem and adding users in the following windows group SQLServerReportServerUser$servername$MSRS10_50.MSSQLSERVER and running IE as Administrator or turning off UAC resolved my problem .

jQuery - multiple $(document).ready ...?

$(document).ready(); is the same as any other function. it fires once the document is ready - ie loaded. the question is about what happens when multiple $(document).ready()'s are fired not when you fire the same function within multiple $(document).ready()'s

//this
<div id="target"></div>

$(document).ready(function(){
   jQuery('#target').append('target edit 1<br>');
});
$(document).ready(function(){
   jQuery('#target').append('target edit 2<br>');
});
$(document).ready(function(){
   jQuery('#target').append('target edit 3<br>');
});

//is the same as
<div id="target"></div>

$(document).ready(function(){

    jQuery('#target').append('target edit 1<br>');

    jQuery('#target').append('target edit 2<br>');

    jQuery('#target').append('target edit 3<br>');

});

both will behave exactly the same. the only difference is that although the former will achieve the same results. the latter will run a fraction of a second faster and requires less typing. :)

in conclusion where ever possible only use 1 $(document).ready();

//old answer

They will both get called in order. Best practice would be to combine them. but dont worry if its not possible. the page will not explode.

On linux SUSE or RedHat, how do I load Python 2.7

The accepted answer by dr jimbob (using make altinstall) got me most of the way there, with python2.7 in /usr/local/bin but I also needed to install some third party modules. The nice thing is that easy_install gets its installation locations from the version of Python you are running, but I found I still needed to install easy_install for Python 2.7 otherwise I would get ImportError: No module named pkg_resources. So I did this:

wget http://pypi.python.org/packages/2.7/s/setuptools/setuptools-0.6c11-py2.7.egg
sudo -i
export PATH=$PATH:/usr/local/bin
sh setuptools-0.6c11-py2.7.egg
exit

Now I have easy_install and easy_install-2.7 in /usr/local/bin and the former overrides my system's 2.6 version of easy_install, so I removed it:

sudo rm /usr/local/bin/easy_install

Now I can install libraries for the 2.7 version of Python like this:

sudo /usr/local/bin/easy_install-2.7 numpy

git with development, staging and production branches

We do it differently. IMHO we do it in an easier way: in master we are working on the next major version.

Each larger feature gets its own branch (derived from master) and will be rebased (+ force pushed) on top of master regularly by the developer. Rebasing only works fine if a single developer works on this feature. If the feature is finished, it will be freshly rebased onto master and then the master fast-forwarded to the latest feature commit.

To avoid the rebasing/forced push one also can merge master changes regularly to the feature branch and if it's finished merge the feature branch into master (normal merge or squash merge). But IMHO this makes the feature branch less clear and makes it much more difficult to reorder/cleanup the commits.

If a new release is coming, we create a side-branch out of master, e.g. release-5 where only bugs get fixed.

Getting an element from a Set

Object objectToGet = ...
Map<Object, Object> map = new HashMap<Object, Object>(set.size());
for (Object o : set) {
    map.put(o, o);
}
Object objectFromSet = map.get(objectToGet);

If you only do one get this will not be very performing because you will loop over all your elements but when performing multiple retrieves on a big set you will notice the difference.

SSIS expression: convert date to string

Something simpler than what @Milen proposed but it gives YYYY-MM-DD instead of the DD-MM-YYYY you wanted :

SUBSTRING((DT_STR,30, 1252) GETDATE(), 1, 10)

Expression builder screen:

What's the difference between session.persist() and session.save() in Hibernate?

Actually, the difference between hibernate save() and persist() methods depends on generator class we are using.
If our generator class is assigned, then there is no difference between save() and persist() methods. Because generator ‘assigned’ means, as a programmer we need to give the primary key value to save in the database right [ Hope you know this generators concept ] In case of other than assigned generator class, suppose if our generator class name is Increment means hibernate itself will assign the primary key id value into the database right [other than assigned generator, hibernate only used to take care the primary key id value remember], so in this case if we call save() or persist() method, then it will insert the record into the database normally.
But here, thing is, save() method can return that primary key id value which is generated by hibernate and we can see it by
long s = session.save(k);
In this same case, persist() will never give any value back to the client, return type void.
persist() also guarantees that it will not execute an INSERT statement if it is called outside of transaction boundaries.
whereas in save(), INSERT happens immediately, no matter if you are inside or outside of a transaction.

How to enable CORS in AngularJs

This issue occurs because of web application security model policy that is Same Origin Policy Under the policy, a web browser permits scripts contained in a first web page to access data in a second web page, but only if both web pages have the same origin. That means requester must match the exact host, protocol, and port of requesting site.

We have multiple options to over come this CORS header issue.

Using Proxy - In this solution we will run a proxy such that when request goes through the proxy it will appear like it is some same origin. If you are using the nodeJS you can use cors-anywhere to do the proxy stuff. https://www.npmjs.com/package/cors-anywhere.

Example:-

var host = process.env.HOST || '0.0.0.0';
var port = process.env.PORT || 8080;
var cors_proxy = require('cors-anywhere');
cors_proxy.createServer({
    originWhitelist: [], // Allow all origins
    requireHeader: ['origin', 'x-requested-with'],
    removeHeaders: ['cookie', 'cookie2']
}).listen(port, host, function() {
    console.log('Running CORS Anywhere on ' + host + ':' + port);
});

JSONP - JSONP is a method for sending JSON data without worrying about cross-domain issues.It does not use the XMLHttpRequest object.It uses the <script> tag instead. https://www.w3schools.com/js/js_json_jsonp.asp
Server Side - On server side we need to enable cross-origin requests. First we will get the Preflighted requests (OPTIONS) and we need to allow the request that is status code 200 (ok).

Preflighted requests first send an HTTP OPTIONS request header to the resource on the other domain, in order to determine whether the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data. In particular, a request is preflighted if it uses methods other than GET or POST. Also, if POST is used to send request data with a Content-Type other than application/x-www-form-urlencoded, multipart/form-data, or text/plain, e.g. if the POST request sends an XML payload to the server using application/xml or text/xml, then the request is preflighted. It sets custom headers in the request (e.g. the request uses a header such as X-PINGOTHER)

If you are using the spring just adding the bellow code will resolves the issue. Here I have disabled the csrf token that doesn't matter enable/disable according to your requirement.
```
@SpringBootApplication
public class SupplierServicesApplication {

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

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**").allowedOrigins("*");
            }
        };
    }
}
```
If you are using the spring security use below code along with above code.
```
@Configuration
@EnableWebSecurity
public class SupplierSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable().authorizeRequests().antMatchers(HttpMethod.OPTIONS, "/**").permitAll().antMatchers("/**").authenticated().and()
                .httpBasic();
    }

}
```

Prevent browser caching of AJAX call result

What about using a POST request instead of a GET...? (Which you should anyway...)

Regex for numbers only

Use the beginning and end anchors.

Regex regex = new Regex(@"^\d$");

Use "^\d+$" if you need to match more than one digit.

Note that "\d" will match [0-9] and other digit characters like the Eastern Arabic numerals ??????????. Use "^[0-9]+$" to restrict matches to just the Arabic numerals 0 - 9.

If you need to include any numeric representations other than just digits (like decimal values for starters), then see @tchrist's comprehensive guide to parsing numbers with regular expressions.

What is the default value for Guid?

To extend answers above, you cannot use Guid default value with Guid.Empty as an optional argument in method, indexer or delegate definition, because it will give you compile time error. Use default(Guid) or new Guid() instead.

How to crop an image using PIL?

You need to import PIL (Pillow) for this. Suppose you have an image of size 1200, 1600. We will crop image from 400, 400 to 800, 800

from PIL import Image
img = Image.open("ImageName.jpg")
area = (400, 400, 800, 800)
cropped_img = img.crop(area)
cropped_img.show()

Static constant string (class member)

The class static variables can be declared in the header but must be defined in a .cpp file. This is because there can be only one instance of a static variable and the compiler can't decide in which generated object file to put it so you have to make the decision, instead.

To keep the definition of a static value with the declaration in C++11 a nested static structure can be used. In this case the static member is a structure and has to be defined in a .cpp file, but the values are in the header.

class A
{
private:
  static struct _Shapes {
     const std::string RECTANGLE {"rectangle"};
     const std::string CIRCLE {"circle"};
  } shape;
};

Instead of initializing individual members the whole static structure is initialized in .cpp:

A::_Shapes A::shape;

The values are accessed with

A::shape.RECTANGLE;

or -- since the members are private and are meant to be used only from A -- with

shape.RECTANGLE;

Note that this solution still suffers from the problem of the order of initialization of the static variables. When a static value is used to initialize another static variable, the first may not be initialized, yet.

// file.h
class File {
public:
  static struct _Extensions {
    const std::string h{ ".h" };
    const std::string hpp{ ".hpp" };
    const std::string c{ ".c" };
    const std::string cpp{ ".cpp" };
  } extension;
};

// file.cpp
File::_Extensions File::extension;

// module.cpp
static std::set<std::string> headers{ File::extension.h, File::extension.hpp };

In this case the static variable headers will contain either { "" } or { ".h", ".hpp" }, depending on the order of initialization created by the linker.

As mentioned by @abyss.7 you could also use constexpr if the value of the variable can be computed at compile time. But if you declare your strings with static constexpr const char* and your program uses std::string otherwise there will be an overhead because a new std::string object will be created every time you use such a constant:

class A {
public:
   static constexpr const char* STRING = "some value";
};
void foo(const std::string& bar);
int main() {
   foo(A::STRING); // a new std::string is constructed and destroyed.
}

How to loop through a JSON object with typescript (Angular2)

Assuming your json object from your GET request looks like the one you posted above simply do:

let list: string[] = [];

json.Results.forEach(element => {
    list.push(element.Id);
});

Or am I missing something that prevents you from doing it this way?

"Proxy server connection failed" in google chrome

Internet explorer has a reset to factory button and luckily so does chrome! try the link below and let us know. the other option is to stop chrome and delete the c:\users\%username%\appdata\local\google folder entirely then reinstall chrome but this will loose all you local settings and data.

Google doc on how to factory reset: https://support.google.com/chrome/answer/3296214?hl=en

setTimeout in for-loop does not print consecutive values

Well, another working solution based on Cody's answer but a little more general can be something like this:

function timedAlert(msg, timing){
    setTimeout(function(){
        alert(msg);    
    }, timing);
}

function yourFunction(time, counter){
    for (var i = 1; i <= counter; i++) {
        var msg = i, timing = i * time * 1000; //this is in seconds
        timedAlert (msg, timing);
    };
}

yourFunction(timeInSeconds, counter); // well here are the values of your choice.

Programmatically add new column to DataGridView

Keep it simple

dataGridView1.Columns.Add("newColumnName", "Column Name in Text");

To add rows

dataGridView1.Rows.Add("Value for column#1"); // [,"column 2",...]

How to install npm peer dependencies automatically?

Install yarn an then run

yarn global add install-peerdeps

Same font except its weight seems different on different browsers

Try text-rendering: geometricPrecision;.

Different from text-rendering: optimizeLegibility;, it takes care of kerning problems when scaling fonts, while the last enables kerning and ligatures.

HTML meta tag for content language

<meta name="language" content="Spanish">

This isn't defined in any specification (including the HTML5 draft)

<meta http-equiv="content-language" content="es">

This is a poor man's version of a real HTTP header and should really be expressed in the headers. For example:

Content-language: es
Content-type: text/html;charset=UTF-8

It says that the document is intended for Spanish language speakers (it doesn't, however mean the document is written in Spanish; it could, for example, be written in English as part of a language course for Spanish speakers).

From the spec:

The Content-Language entity-header field describes the natural language(s) of the intended audience for the enclosed entity. Note that this might not be equivalent to all the languages used within the entity-body.

If you want to state that a document is written in Spanish then use:

<html lang="es">

How to use boolean datatype in C?

C99 has a boolean datatype, actually, but if you must use older versions, just define a type:

typedef enum {false=0, true=1} bool;

Running Google Maps v2 on the Android emulator

I recommend using the emulator by Genymotion instead of Google's emulators. It launches way faster and responds almost in real-time. It also supports Google Play Services and therefore Google Maps.

Google Maps on Genymotion

Give it a try! Here is a blog post which helps you setting up the emulator.

How to set up a fast emulator for Android on Linux?

How to use UTF-8 in resource properties with ResourceBundle

From Java 9, the default to load properties file has been changed to UTF-8. https://docs.oracle.com/javase/9/intl/internationalization-enhancements-jdk-9.htm

What is the best way to remove accents (normalize) in a Python unicode string?

Unidecode is the correct answer for this. It transliterates any unicode string into the closest possible representation in ascii text.

Example:

accented_string = u'Málaga'
# accented_string is of type 'unicode'
import unidecode
unaccented_string = unidecode.unidecode(accented_string)
# unaccented_string contains 'Malaga'and is of type 'str'

Flattening a shallow list in Python

What about:

from operator import add
reduce(add, map(lambda x: list(x.image_set.all()), [mi for mi in list_of_menuitems]))

But, Guido is recommending against performing too much in a single line of code since it reduces readability. There is minimal, if any, performance gain by performing what you want in a single line vs. multiple lines.

Programs & Examples On #Serving

How to integrate Dart into a Rails app

Can't perform a React state update on an unmounted component

How to handle "Uncaught (in promise) DOMException: play() failed because the user didn't interact with the document first." on Desktop with Chrome 66?

Angular: Cannot Get /

Why I can't access remote Jupyter Notebook server?

Are dictionaries ordered in Python 3.6+?

angular-cli server - how to proxy API requests to another server?

How do I pass data to Angular routed components?

XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header

How do you deploy Angular apps?

Delegation: EventEmitter or Observable in Angular

Webpack "OTS parsing error" loading fonts

Get list of filenames in folder with Javascript

The service cannot accept control messages at this time

"Could not find acceptable representation" using spring-boot-starter-web

How to convert entire dataframe to numeric while preserving decimals?

java.net.SocketException: Connection reset by peer: socket write error When serving a file

Serving static web resources in Spring Boot & Spring Security application

Spring Boot not serving static content

Flask Download a File

PostgreSQL return result set as JSON array?

TL;DR

List of objects

9.3 and up

9.2

Object of lists

9.5 and up

9.4 and 9.3

9.2

Documentation

Design

Nulls

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyController':

How to use the 'main' parameter in package.json?

json: cannot unmarshal object into Go value of type

PUT and POST getting 405 Method Not Allowed Error for Restful Web Services

Add x and y labels to a pandas plot

Launching Spring application Address already in use

Cloudfront custom-origin distribution returns 502 "ERROR The request could not be satisfied." for some URLs

How to serve static files in Flask

How do I get Flask to run on port 80?

How do you decrease navbar height in Bootstrap 3?

Map over object preserving keys

AngularJS: how to enable $locationProvider.html5Mode with deeplinking

Difference between no-cache and must-revalidate

How can I make this try_files directive work?

Moving Git repository content to another repository preserving history

Differences between hard real-time, soft real-time, and firm real-time?

Can local storage ever be considered secure?

Git copy file preserving history

Convert pandas timezone-aware DateTimeIndex to naive timestamp, but in certain timezone

S3 Static Website Hosting Route All Paths to Index.html

Can I delete a git commit but keep the changes?

Can I serve multiple clients using just Flask app.run() as standalone?

How to capture no file for fs.readFileSync()?

making matplotlib scatter plots from dataframes in Python's pandas

How to force addition instead of concatenation in javascript

Correct MIME Type for favicon.ico?

HAProxy redirecting http to https (ssl)

CORS Access-Control-Allow-Headers wildcard being ignored?

.htaccess Example (CORS Included):

F.A.Q:

Where can I find the Tomcat 7 installation folder on Linux AMI in Elastic Beanstalk?

Copying the cell value preserving the formatting from one cell to another in excel using VBA

How to set max width of an image in CSS

trace a particular IP and port

How many concurrent requests does a single Flask process receive?

Error message "Forbidden You don't have permission to access / on this server"

Nginx -- static file serving confusion with root & alias

Error creating bean with name

How to send data in request body with a GET when using jQuery $.ajax()

Adding a favicon to a static HTML page

"Cannot GET /" with Connect on Node.js

best way to preserve numpy arrays on disk

Node JS Error: ENOENT

Spring 3 MVC resources and tag <mvc:resources />

Strange Characters in database text: Ã, Ã, ¢, â‚ €,

Tuning nginx worker_process to obtain 100k hits per min

Apply function to each column in a data frame observing each columns existing data type

`.htaccess` Example (CORS Included):

The reason `textarea`

The reason `a` and `button`