Programs & Examples On #Webcontent

com.apple.WebKit.WebContent drops 113 error: Could not find specified service

On OS X, it's necessary to make sure Sandbox capabilities are set-up properly in order to use WKWebView.

This link made this clear to me: https://forums.developer.apple.com/thread/92265

Sharing hoping that it will help someone.


Select the Project File in the Navigator, select Capabilities, then make sure that:
* App Sandbox is OFF,
OR
* App Sandbox is ON AND Outgoing Connections (Client) is checked.

BootStrap : Uncaught TypeError: $(...).datetimepicker is not a function

You are using an old version of the date picker js. Upgrade datepicker js with latest one.

Replace your bootstrap-datetimepicker.min.js file with this will work..

<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/3.1.3/js/bootstrap-datetimepicker.min.js"></script>

Direct download from Google Drive using Google Drive API

Using a Service Account might work for you.

org.apache.jasper.JasperException: Unable to compile class for JSP:

The problem is caused because you need to import the pageNumber.Member class in your JSP. Make sure to also include another packages and classes like java.util.List.

<%@ page import="pageNumber.*, java.util.*" %>

Still, you have a major problem by using scriptlets in your JSP. Refer to How to avoid Java Code in JSP-Files? and start practicing EL and JSTL and focusing more on a MVC solution instead.

Google drive limit number of download

This limit is indeed not specified, however their TOS mentions that: "FOR EXAMPLE, WE DON’T MAKE ANY COMMITMENTS ABOUT THE CONTENT WITHIN THE SERVICES, THE SPECIFIC FUNCTIONS OF THE SERVICES, OR THEIR RELIABILITY, AVAILABILITY, OR ABILITY TO MEET YOUR NEEDS. WE PROVIDE THE SERVICES “AS IS”. "

This means to me that the download limit is calculated based on a set of factors that describe the user and is subject to change from one to another.

Maybe using the TOR network may help you do your job.

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

Scenario #1: You accidentially re-deployed from the command line while tomcat was already running.

Short Answer: Stop Tomcat, delete target folder, mvn package, then re-deploy


Scenario #2: request.getRequestDispatcher("MIS_SPELLED_FILE_NAME.jsp")

Short Answer: Check file name spelling, make sure case is correct.


Scenario #3: Class Not Found Exceptions (Answer put here because: Question# 17982240 ) (java.lang.ClassNotFoundException for servlet in tomcat with eclipse ) (was marked as duplicate and directed me here )

Short Answer #3.1: web.xml has wrong package path in servlet-class tag.

Short Answer #3.2: java file has wrong import statement.


Below is further details for Scenario #1:


1: Stop Tomcat

  • Option 1: Via CTRL+C in terminal.
  • Option 2: (terminal closed while tomcat still running)
  • ------------ 2.1: press:Windows+R --> type:"services.msc"
  • ------------ 2.2: Find "Apache Tomcat #.# Tomcat#" in Name column of list.
  • ------------ 2.3: Right Click --> "stop"

2: Delete the "target" folder. (mvn clean will not help you here)

3: mvn package

4: YOUR_DEPLOYMENT_COMMAND_HERE

(Mine: java -jar target/dependency/webapp-runner.jar --port 5190 target/*.war )

Full Back Story:


Accidentially opened a new git-bash window and tried to deploy a .war file for my heroku project via:

java -jar target/dependency/webapp-runner.jar --port 5190 target/*.war

After a failure to deploy, I realized I had two git-bash windows open, and had not used CTLR+C to stop the previous deployment.

I was met with:

HTTP Status 404 – Not Found Type Status Report

Message /if-student-test.jsp

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

Apache Tomcat/8.5.31

Below is further details for Scenario #3:


SCENARIO 3.1: The servlet-class package path is wrong in your web.xml file.

It should MATCH the package statement at top of your java servlet class.

File: my_stuff/MyClass.java:

   package my_stuff;

File: PRJ_ROOT/src/main/webapp/WEB-INF/web.xml

   <servlet-class>
   my_stuff.MyClass
   </servlet-class>

SCENARIO 3.2:

You put the wrong "package" statement at top of your myClass.java file.

For example:

File is in: "/my_stuff" folder

You mistakenly write:

package com.my_stuff

This is tricky because:

1: The maven build (mvn package) will not report any errors here.

2: servlet-class line in web.xml can have CORRECT package path. E.g:

<servlet-class>
my_stuff.MyClass
</servlet-class>

Stack Used: Notepad++ + GitBash + Maven + Heroku Web App Runner + Tomcat9 + Windows10:

How to get RegistrationID using GCM in android

Use this code to get Registration ID using GCM

String regId = "", msg = "";

public void getRegisterationID() {

    new AsyncTask() {
        @Override
        protected Object doInBackground(Object...params) {

            String msg = "";
            try {
                if (gcm == null) {
                    gcm = GoogleCloudMessaging.getInstance(Login.this);
                }
                regId = gcm.register(YOUR_SENDER_ID);
                Log.d("in async task", regId);

                // try
                msg = "Device registered, registration ID=" + regId;

            } catch (IOException ex) {
                msg = "Error :" + ex.getMessage();
            }
            return msg;
        }
    }.execute(null, null, null);
 }

and don't forget to write permissions in manifest...
I hope it helps!

Eclipse Build Path Nesting Errors

Try this:

From the libraries tab:

Eclipse -> right click on project name in sidebar -> configure build path -> Libraries

Remove your web app libraries:

click on "Web App Libraries" -> click "remove"

Add them back in:

click "Add Library" -> click to highlight "Web App Libraries" -> click "next" -> confirm your desired project is the selected option -> click "Finish"

Highlighting "Web App Libraries":

Highlighting "Web App Libraries"

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'customerService' is defined

Please make sure that your applicationContext.xml file is loaded by specifying it in your web.xml file:

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>

scale fit mobile web content using viewport meta tag

I had same problem as yours, but my concern was list view. When i try to scroll list view fixed header also scroll little bit. Problem was list view height smaller than viewport (browser) height. You just need to reduce your viewport height lower than content tag (list view within content tag) height. Here is my meta tag;

<meta name="viewport" content="width=device-width,height=90%,  user-scalable = no"> 

Hope this will help.Thnks.

how to load CSS file into jsp

You can write like that. This is for whenever you change context path you don't need to modify your jsp file.

<link rel="stylesheet" href="${pageContext.request.contextPath}/css/styles.css" />

How get the base URL via context path in JSF?

JSTL 1.2 variation leveraged from BalusC answer

<c:set var="baseURL" value="${pageContext.request.requestURL.substring(0, pageContext.request.requestURL.length() - pageContext.request.requestURI.length())}${pageContext.request.contextPath}/" />

<head>
  <base href="${baseURL}" />

Configure hibernate to connect to database via JNDI Datasource

I was getting the same error in my IBM Websphere with c3p0 jar files. I have Oracle 10g database. I simply added the oraclejdbc.jar files in the Application server JVM in IBM Classpath using Websphere Console and the error was resolved.

The oraclejdbc.jar should be set with your C3P0 jar files in your Server Class path whatever it be tomcat, glassfish of IBM.

Ant build failed: "Target "build..xml" does not exist"

  1. Probably you don't have environment variable ANT_HOME set properly
  2. It seems that you are calling Ant like this: "ant build..xml". If your ant script has name build.xml you need to specify only a target in command line. For example: "ant target1".

:touch CSS pseudo-class or something similar?

Since mobile doesn't give hover feedback, I want, as a user, to see instant feedback when a link is tapped. I noticed that -webkit-tap-highlight-color is the fastest to respond (subjective).

Add the following to your body and your links will have a tap effect.

body {
    -webkit-tap-highlight-color: #ccc;
}

If Radio Button is selected, perform validation on Checkboxes

function validateDays() {
    if (document.getElementById("option1").checked == true) {
        alert("You have selected Option 1");
    }
    else if (document.getElementById("option2").checked == true) {
        alert("You have selected Option 2");
    }
    else if (document.getElementById("option3").checked == true) {
        alert("You have selected Option 3");
    }
    else {
        // DO NOTHING
        }
    }

How to set a Fragment tag by code?

Yes. So the only way is at transaction time, e.g. using add, replace, or as part of the layout.

I determined this through an examination of the compatibility sources as I briefly looked for similar at some point in the past.

How can I check whether a radio button is selected with JavaScript?

An example:

if (!checkRadioArray(document.ExamEntry.level)) { 
    msg+="What is your level of entry? \n"; 
    document.getElementById('entry').style.color="red"; 
    result = false; 
} 

if(msg==""){ 
    return result;  
} 
else{ 
    alert(msg) 
    return result;
} 

function Radio() { 
    var level = radio.value; 
    alert("Your level is: " + level + " \nIf this is not the level your taking then please choose another.") 
} 

function checkRadioArray(radioButtons) { 
    for(var r=0;r < radioButtons.length; r++) { 
        if (radioButtons[r].checked) { 
            return true; 
        } 
    } 
    return false; 
} 

What is the exact meaning of Git Bash?

Bash is a Command Line Interface that was created over twenty-seven years ago by Brian Fox as a free software replacement for the Bourne Shell. A shell is a specific kind of Command Line Interface. Bash is "open source" which means that anyone can read the code and suggest changes. Since its beginning, it has been supported by a large community of engineers who have worked to make it an incredible tool. Bash is the default shell for Linux and Mac. For these reasons, Bash is the most used and widely distributed shell.

Windows has a different Command Line Interface, called Command Prompt. While this has many of the same features as Bash, Bash is much more popular. Because of the strength of the open source community and the tools they provide, mastering Bash is a better investment than mastering Command Prompt.

To use Bash on a Windows computer, we need to download and install a program called Git Bash. Git Bash (Is the Bash for windows) allows us to easily access Bash as well as another tool called Git, inside the Windows environment.

How can I get the timezone name in JavaScript?

You can simply write your own code by using the mapping table here: http://www.timeanddate.com/time/zones/

or, use moment-timezone library: http://momentjs.com/timezone/docs/

See zone.name; // America/Los_Angeles

or, this library: https://github.com/Canop/tzdetect.js

How do you convert a byte array to a hexadecimal string in C?

I know this question already has an answer but I think my solution could help someone.

So, in my case I had a byte array representing the key and I needed to convert this byte array to char array of hexadecimal values in order to print it out in one line. I extracted my code to a function like this:

char const * keyToStr(uint8_t const *key)
{
    uint8_t offset = 0;
    static char keyStr[2 * KEY_SIZE + 1];

    for (size_t i = 0; i < KEY_SIZE; i++)
    {
        offset += sprintf(keyStr + offset, "%02X", key[i]);
    }
    sprintf(keyStr + offset, "%c", '\0');

    return keyStr;
}

Now, I can use my function like this:

Serial.print("Public key: ");
Serial.println(keyToStr(m_publicKey));

Serial object is part of Arduino library and m_publicKey is member of my class with the following declaration uint8_t m_publicKey[32].

Python extending with - using super() Python 3 vs Python 2

Just to have a simple and complete example for Python 3, which most people seem to be using now.

class MySuper(object):
    def __init__(self,a):
        self.a = a

class MySub(MySuper):
    def __init__(self,a,b):
        self.b = b
        super().__init__(a)

my_sub = MySub(42,'chickenman')
print(my_sub.a)
print(my_sub.b)

gives

42
chickenman

C# '@' before a String

As a side note, you also should keep in mind that "escaping" means "using the back-slash as an indicator for special characters". You can put an end of line in a string doing that, for instance:

String foo = "Hello\

There";

Use basic authentication with jQuery and Ajax

There are 3 ways to achieve this as shown below

Method 1:

var uName="abc";
var passwrd="pqr";

$.ajax({
    type: '{GET/POST}',
    url: '{urlpath}',
    headers: {
        "Authorization": "Basic " + btoa(uName+":"+passwrd);
    },
    success : function(data) {
      //Success block  
    },
   error: function (xhr,ajaxOptions,throwError){
    //Error block 
  },
});

Method 2:

var uName="abc";
var passwrd="pqr";

$.ajax({
    type: '{GET/POST}',
    url: '{urlpath}',
     beforeSend: function (xhr){ 
        xhr.setRequestHeader('Authorization', "Basic " + btoa(uName+":"+passwrd)); 
    },
    success : function(data) {
      //Success block 
   },
   error: function (xhr,ajaxOptions,throwError){
    //Error block 
  },
});

Method 3:

var uName="abc";
var passwrd="pqr";

$.ajax({
    type: '{GET/POST}',
    url: '{urlpath}',
    username:uName,
    password:passwrd, 
    success : function(data) {
    //Success block  
   },
    error: function (xhr,ajaxOptions,throwError){
    //Error block 
  },
});

Remove a character at a certain position in a string - javascript

    var str = 'Hello World';
                str = setCharAt(str, 3, '');
                alert(str);

function setCharAt(str, index, chr)
        {
            if (index > str.length - 1) return str;
            return str.substr(0, index) + chr + str.substr(index + 1);
        }

changing visibility using javascript

If you just want to display it when you get a response add this to your loadpage()

function loadpage(page_request, containerid){
   if (page_request.readyState == 4 && page_request.status==200) { 
      var container = document.getElementById(containerid);
      container.innerHTML=page_request.responseText;
      container.style.visibility = 'visible';
      // or 
      container.style.display = 'block';
}

but this depend entirely on how you hid the div in the first place

Convert hexadecimal string (hex) to a binary string

import java.util.*;
public class HexadeciamlToBinary
{
   public static void main()
   {
       Scanner sc=new Scanner(System.in);
       System.out.println("enter the hexadecimal number");
       String s=sc.nextLine();
       String p="";
       long n=0;
       int c=0;
       for(int i=s.length()-1;i>=0;i--)
       {
          if(s.charAt(i)=='A')
          {
             n=n+(long)(Math.pow(16,c)*10);
             c++;
          }
         else if(s.charAt(i)=='B')
         {
            n=n+(long)(Math.pow(16,c)*11);
            c++;
         }
        else if(s.charAt(i)=='C')
        {
            n=n+(long)(Math.pow(16,c)*12);
            c++;
        }
        else if(s.charAt(i)=='D')
        {
           n=n+(long)(Math.pow(16,c)*13);
           c++;
        }
        else if(s.charAt(i)=='E')
        {
            n=n+(long)(Math.pow(16,c)*14);
            c++;
        }
        else if(s.charAt(i)=='F')
        {
            n=n+(long)(Math.pow(16,c)*15);
            c++;
        }
        else
        {
            n=n+(long)Math.pow(16,c)*(long)s.charAt(i);
            c++;
        }
    }
    String s1="",k="";
    if(n>1)
    {
    while(n>0)
    {
        if(n%2==0)
        {
            k=k+"0";
            n=n/2;
        }
        else
        {
            k=k+"1";
            n=n/2;
        }
    }
    for(int i=0;i<k.length();i++)
    {
        s1=k.charAt(i)+s1;
    }
    System.out.println("The respective binary number is : "+s1);
    }
    else
    {
        System.out.println("The respective binary number is : "+n);
    }
  }
}

MySQL Foreign Key Error 1005 errno 150 primary key as foreign key

I had the exact same problem, but the solution to my problem was entirely different. I had, somewhere else in the database, a foreign key with the same name. That caused the error 1005.

Renaming my foreign key to something more specific to that situation solved the problem.

How To Set Text In An EditText

If you want to set text at design time in xml file just simple android:text="username" add this property.

<EditText
    android:id="@+id/edtUsername"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="username"/>

If you want to set text programmatically in Java

EditText edtUsername = findViewById(R.id.edtUsername);
edtUsername.setText("username");

and in kotlin same like java using getter/setter

edtUsername.setText("username")

But if you want to use .text from principle then

edtUsername.text = Editable.Factory.getInstance().newEditable("username")

because of EditText.text requires an editable at firstplace not String

What is the easiest way to install BLAS and LAPACK for scipy?

Either use SciPy whl, download the appropriate one and run pip install <whl_file>

OR

Read through SciPy Windows issue and run one of the methods.

OR

Use Miniconda.

Additionally, install Visual C++ compiler for python2.7 in-case it asks for it.

How to remove all elements in String array in java?

list.clear() is documented for clearing the ArrayList.

list.removeAll() has no documentation at all in Eclipse.

Maven: Failed to read artifact descriptor

You can always try mvn -U clean install

-U forces a check for updated releases and snapshots on remote repositories.

Refused to load the font 'data:font/woff.....'it violates the following Content Security Policy directive: "default-src 'self'". Note that 'font-src'

You would have used inline styles at many places, which CSP(Content Security Policy) prohibits because it could be dangerous.

Just try removing those inline styles and put it inside dedicated stylesheet.

How do I add a Font Awesome icon to input field?

You can use another tag instead of input and apply FontAwesome the normal way.

instead of your input with type image you can use this:

<i class="icon-search icon-2x"></i>

quick CSS:

.icon-search {
    color:white;
    background-color:black;
}

Here is a quick fiddle: DEMO

You can style it a little better and add event functionality, to the i object, which you can do by using a <button type="submit"> object instead of i, or with javascript.

The button sollution would be something like this:

<button type="submit" class="icon-search icon-large"></button>

And the CSS:

.icon-search {
    height:32px;
    width:32px;
    border: none;
    cursor: pointer;
    color:white;
    background-color:black;
    position:relative;
}

here is my fiddle updated with the button instead of i: DEMO


Update: Using FontAwesome on any tag

The problem with FontAwsome is that its stylesheet uses :before pseudo-elements to add the icons to an element - and pseudo elements don't work/are not allowed on input elements. This is why using FontAwesome the normal way will not work with input.

But there is a solution - you can use FontAwesome as a regular font like so:

CSS:

input[type="submit"] {
    font-family: FontAwesome;
}

HTML:

<input type="submit" class="search" value="&#xf002;" />

The glyphs can be passed as values of the value attribute. The ascii codes for the individual letters/icons can be found in the FontAwesome css file, you just need to change them into a HTML ascii number like \f002 to &#xf002; and it should work.

Link to the FontAwesome ascii code (cheatsheet): fortawesome.github.io/Font-Awesome/cheatsheet

The size of the icons can be easily adjusted via font-size.

See the above example using an input element in a jsfidde:

DEMO


Update: FontAwesome 5

With FontAwesome version 5 the CSS required for this solution has changed - the font family name has changed and the font weight must be specified:

input[type="submit"] {
    font-family: "Font Awesome 5 Free"; // for the open access version
    font-size: 1.3333333333333333em;
    font-weight: 900;
}

See @WillFastie 's comment with link to updated fiddle bellow. Thanks!

How does @synchronized lock/unlock in Objective-C?

The Objective-C language level synchronization uses the mutex, just like NSLock does. Semantically there are some small technical differences, but it is basically correct to think of them as two separate interfaces implemented on top of a common (more primitive) entity.

In particular with a NSLock you have an explicit lock whereas with @synchronized you have an implicit lock associated with the object you are using to synchronize. The benefit of the language level locking is the compiler understands it so it can deal with scoping issues, but mechanically they behave basically the same.

You can think of @synchronized as a compiler rewrite:

- (NSString *)myString {
  @synchronized(self) {
    return [[myString retain] autorelease];
  }
}

is transformed into:

- (NSString *)myString {
  NSString *retval = nil;
  pthread_mutex_t *self_mutex = LOOK_UP_MUTEX(self);
  pthread_mutex_lock(self_mutex);
  retval = [[myString retain] autorelease];
  pthread_mutex_unlock(self_mutex);
  return retval;
}

That is not exactly correct because the actual transform is more complex and uses recursive locks, but it should get the point across.

How to fix nginx throws 400 bad request headers on any header testing tools?

Yes changing the error_to debug level as Emmanuel Joubaud suggested worked out (edit /etc/nginx/sites-enabled/default ):

        error_log /var/log/nginx/error.log debug;

Then after restaring nginx I got in the error log with my Python application using uwsgi:

        2017/02/08 22:32:24 [debug] 1322#1322: *1 connect to unix:///run/uwsgi/app/socket, fd:20 #2
        2017/02/08 22:32:24 [debug] 1322#1322: *1 connected
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http upstream connect: 0
        2017/02/08 22:32:24 [debug] 1322#1322: *1 posix_memalign: 0000560E1F25A2A0:128 @16
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http upstream send request
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http upstream send request body
        2017/02/08 22:32:24 [debug] 1322#1322: *1 chain writer buf fl:0 s:454
        2017/02/08 22:32:24 [debug] 1322#1322: *1 chain writer in: 0000560E1F2A0928
        2017/02/08 22:32:24 [debug] 1322#1322: *1 writev: 454 of 454
        2017/02/08 22:32:24 [debug] 1322#1322: *1 chain writer out: 0000000000000000
        2017/02/08 22:32:24 [debug] 1322#1322: *1 event timer add: 20: 60000:1486593204249
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http finalize request: -4, "/?" a:1, c:2
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http request count:2 blk:0
        2017/02/08 22:32:24 [debug] 1322#1322: *1 post event 0000560E1F2E5DE0
        2017/02/08 22:32:24 [debug] 1322#1322: *1 post event 0000560E1F2E5E40
        2017/02/08 22:32:24 [debug] 1322#1322: *1 delete posted event 0000560E1F2E5DE0
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http run request: "/?"
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http upstream check client, write event:1, "/"
        2017/02/08 22:32:24 [debug] 1322#1322: *1 http upstream recv(): -1 (11: Resource temporarily unavailable)

Then I took a look to my uwsgi log and found out that:

        Invalid HTTP_HOST header: 'www.mysite.local'. You may need to add u'www.mysite.local' to ALLOWED_HOSTS.
        [pid: 10903|app: 0|req: 2/4] 192.168.221.2 () {38 vars in 450 bytes} [Wed Feb  8 22:32:24 2017] GET / => generated 54098 bytes in 55 msecs (HTTP/1.1 400) 4 headers in 135 bytes (1 switches on core 0)

And adding www.mysite.local to the settings.py ALLOWED_HOSTS fixed the issue :)

        ALLOWED_HOSTS = ['www.mysite.local']

How to store Node.js deployment settings/configuration files?

npm i config

In config/default.json
{
    "app": {
        "port": 3000
    },
    "db": {
        "port": 27017,
        "name": "dev_db_name"
    }
}

In config/production.json
{
    "app": {
        "port": 4000
    },
    "db": {
        "port": 27000,
        "name": "prod_db_name"
    }
}

In index.js

const config = require('config');

let appPort = config.get('app.port');
console.log(`Application port: ${appPort}`);

let dbPort = config.get('db.port');
console.log(`Database port: ${dbPort}`);

let dbName = config.get('db.name');
console.log(`Database name: ${dbName}`);

console.log('NODE_ENV: ' + config.util.getEnv('NODE_ENV'));

$ node index.js
Application port: 3000
Database port: 27017
Database name: dev_db_name
NODE_ENV: development

For production
$ set NODE_ENV=production
$ node index.js
Application port: 4000
Database port: 27000
Database name: prod_db_name
NODE_ENV: production

JQuery add class to parent element

$(this.parentNode).addClass('newClass');

Setting CSS pseudo-class rules from JavaScript

You can't style a pseudo-class on a particular element alone, in the same way that you can't have a pseudo-class in an inline style="..." attribute (as there is no selector).

You can do it by altering the stylesheet, for example by adding the rule:

#elid:hover { background: red; }

assuming each element you want to affect has a unique ID to allow it to be selected.

In theory the document you want is http://www.w3.org/TR/DOM-Level-2-Style/Overview.html which means you can (given a pre-existing embedded or linked stylesheet) using syntax like:

document.styleSheets[0].insertRule('#elid:hover { background-color: red; }', 0);
document.styleSheets[0].cssRules[0].style.backgroundColor= 'red';

IE, of course, requires its own syntax:

document.styleSheets[0].addRule('#elid:hover', 'background-color: red', 0);
document.styleSheets[0].rules[0].style.backgroundColor= 'red';

Older and minor browsers are likely not to support either syntax. Dynamic stylesheet-fiddling is rarely done because it's quite annoying to get right, rarely needed, and historically troublesome.

How to convert a String to Bytearray

I suppose C# and Java produce equal byte arrays. If you have non-ASCII characters, it's not enough to add an additional 0. My example contains a few special characters:

var str = "Hell ö € O ";
var bytes = [];
var charCode;

for (var i = 0; i < str.length; ++i)
{
    charCode = str.charCodeAt(i);
    bytes.push((charCode & 0xFF00) >> 8);
    bytes.push(charCode & 0xFF);
}

alert(bytes.join(' '));
// 0 72 0 101 0 108 0 108 0 32 0 246 0 32 32 172 0 32 3 169 0 32 216 52 221 30

I don't know if C# places BOM (Byte Order Marks), but if using UTF-16, Java String.getBytes adds following bytes: 254 255.

String s = "Hell ö € O ";
// now add a character outside the BMP (Basic Multilingual Plane)
// we take the violin-symbol (U+1D11E) MUSICAL SYMBOL G CLEF
s += new String(Character.toChars(0x1D11E));
// surrogate codepoints are: d834, dd1e, so one could also write "\ud834\udd1e"

byte[] bytes = s.getBytes("UTF-16");
for (byte aByte : bytes) {
    System.out.print((0xFF & aByte) + " ");
}
// 254 255 0 72 0 101 0 108 0 108 0 32 0 246 0 32 32 172 0 32 3 169 0 32 216 52 221 30

Edit:

Added a special character (U+1D11E) MUSICAL SYMBOL G CLEF (outside BPM, so taking not only 2 bytes in UTF-16, but 4.

Current JavaScript versions use "UCS-2" internally, so this symbol takes the space of 2 normal characters.

I'm not sure but when using charCodeAt it seems we get exactly the surrogate codepoints also used in UTF-16, so non-BPM characters are handled correctly.

This problem is absolutely non-trivial. It might depend on the used JavaScript versions and engines. So if you want reliable solutions, you should have a look at:

How to use cURL in Java?

Some people have already mentioned HttpURLConnection, URL and URLConnection. If you need all the control and extra features that the curl library provides you (and more), I'd recommend Apache's httpclient.

What is the difference between public, protected, package-private and private in Java?

Access modifiers are there to restrict access at several levels.

Public: It is basically as simple as you can access from any class whether that is in same package or not.

To access if you are in same package you can access directly, but if you are in another package then you can create an object of the class.

Default: It is accessible in the same package from any of the class of package.

To access you can create an object of the class. But you can not access this variable outside of the package.

Protected: you can access variables in same package as well as subclass in any other package. so basically it is default + Inherited behavior.

To access protected field defined in base class you can create object of child class.

Private: it can be access in same class.

In non-static methods you can access directly because of this reference (also in constructors)but to access in static methods you need to create object of the class.

Correct way to work with vector of arrays

Use:

vector<vector<float>> vecArray; //both dimensions are open!

Moving items around in an ArrayList

Applying recursion to reorder items in an arraylist

public class ArrayListUtils {
            public static <T> void reArrange(List<T> list,int from, int to){
                if(from != to){
                     if(from > to)
                        reArrange(list,from -1, to);
                      else
                        reArrange(list,from +1, to);

                     Collections.swap(list, from, to);
                }
            }
    }

INSERT ... ON DUPLICATE KEY (do nothing)

Yes, use INSERT ... ON DUPLICATE KEY UPDATE id=id (it won't trigger row update even though id is assigned to itself).

If you don't care about errors (conversion errors, foreign key errors) and autoincrement field exhaustion (it's incremented even if the row is not inserted due to duplicate key), then use INSERT IGNORE.

if condition in sql server update query

Since you're using SQL 2008:

UPDATE
    table_Name

SET
    column_A  
     = CASE
        WHEN @flag = '1' THEN @new_value
        ELSE 0
    END + column_A,

    column_B  
     = CASE
        WHEN @flag = '0' THEN @new_value
        ELSE 0
    END + column_B 
WHERE
    ID = @ID

If you were using SQL 2012:

UPDATE
    table_Name
SET
    column_A  = column_A + IIF(@flag = '1', @new_value, 0),
    column_B  = column_B + IIF(@flag = '0', @new_value, 0)
WHERE
    ID = @ID

Enable the display of line numbers in Visual Studio

Line numbers are not on by default. To turn on line numbers just go to Tools -> Options -> Text Editor -> All Languages -> General -> Display and check Line numbers:

http://blogs.msdn.com/blogfiles/zainnab/WindowsLiveWriter/TurnonLineNumbers_A5E7/image_thumb.png

List Git commits not pushed to the origin yet

git log origin/master..master

or, more generally:

git log <since>..<until>

You can use this with grep to check for a specific, known commit:

git log <since>..<until> | grep <commit-hash>

Or you can also use git-rev-list to search for a specific commit:

git rev-list origin/master | grep <commit-hash>

Get response from PHP file using AJAX

<script type="text/javascript">
        function returnwasset(){
            alert('return sent');
            $.ajax({
                type: "POST",
                url: "process.php",
                data: somedata;
                dataType:'text'; //or HTML, JSON, etc.
                success: function(response){
                    alert(response);
                    //echo what the server sent back...
                }
            });
        }
    </script>

Convert date to YYYYMM format

You can convert your date in many formats, for example :

CONVERT(NVARCHAR(10), DATE_OF_DAY, 103) => 15/09/2016
CONVERT(NVARCHAR(10), DATE_OF_DAY, 3) => 15/09/16

Syntaxe :

CONVERT('TheTypeYouWant', 'TheDateToConvert', 'TheCodeForFormating' * )
  • The code is an integer, here 3 is the third formating without century, if you want the century just change the code to 103.

In your case, i've just converted and restrict size by nvarchar(6) like this :

CONVERT(NVARCHAR(6), DATE_OF_DAY, 112) => 201609

See more at : http://www.w3schools.com/sql/func_convert.asp

Is it possible to disable floating headers in UITableView with UITableViewStylePlain?

A tricky way is add an empty section for header. Because section has no cell, it will not floating at all.

How do you configure HttpOnly cookies in tomcat / java webapps?

For cookies that I am explicitly setting, I switched to use SimpleCookie provided by Apache Shiro. It does not inherit from javax.servlet.http.Cookie so it takes a bit more juggling to get everything to work correctly however it does provide a property set HttpOnly and it works with Servlet 2.5.

For setting a cookie on a response, rather than doing response.addCookie(cookie) you need to do cookie.saveTo(request, response).

How to get a random value from dictionary?

If you don't want to use random.choice() you can try this way:

>>> list(myDictionary)[i]
'VENEZUELA'
>>> myDictionary = {'VENEZUELA':'CARACAS', 'IRAN' : 'TEHRAN'}
>>> import random
>>> i = random.randint(0, len(myDictionary) - 1)
>>> myDictionary[list(myDictionary)[i]]
'TEHRAN'
>>> list(myDictionary)[i]
'IRAN'

HTML5 Number Input - Always show 2 decimal places

The solutions which use input="number" step="0.01" work great for me in Chrome, however do not work in some browsers, specifically Frontmotion Firefox 35 in my case.. which I must support.

My solution was to jQuery with Igor Escobar's jQuery Mask plugin, as follows:

_x000D_
_x000D_
$(document).ready(function () {
  $('.usd_input').mask('00000.00', { reverse: true });
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.mask/1.14.16/jquery.mask.min.js" integrity="sha512-pHVGpX7F/27yZ0ISY+VVjyULApbDlD0/X0rgGbTqCE7WFW5MezNTWG/dnhtbBuICzsd0WQPgpE4REBLv+UqChw==" crossorigin="anonymous"></script>

<input type="text" autocomplete="off" class="usd_input" name="dollar_amt">
_x000D_
_x000D_
_x000D_

This works well, of course one should check the submitted value afterward :) NOTE, if I did not have to do this for browser compatibility I would use the above answer by @Rich Bradshaw.

Use different Python version with virtualenv

Here is the stepbystep how to create the Virtual environment in Visual Studio Code folder: I used Powershell (Administrator mode):
1. I create a VSCode folder - "D:\Code_Python_VE" where I want to create Virtual environment.
2. Next I type the command - "pip3 install virtualenv". (D:\Code_Python_VE> pip3 install virtualenv) 3. D:\Code_Python_VE> python3 -m venv project_env
4. D:\Code_Python_VE>project_env\Scripts\activate.bat
5. D:\Code_Python_VE> ls - This will list a new directory "project_env".
6. D:\Code_Python_VE> code . This will start Visual Studio Code. Make sure the command is (code .).
7. Create launch.jason with following content:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "python",
            "request": "launch",
            "name": "Python: Current File (Integrated Terminal 1)",
            "program": "${file}"
        },
        {
            "name": "Python: Current File (Integrated Terminal 2)",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal"
        }
    ]
}

(Please search how to go to Debug window and Add new Configuration in VS Code).

  1. Press F1 in Visual studio code and the command pallet will open - Select Python Interpreter and select the virtual environment project_env.
  2. Add test.py file with one statement print("Hello World").
  3. Run this program.
  4. In Visual studio Code terminal -
    (project_env) d:\Code_Python_VE>python -m pip install --upgrade
    I hope this helps.

How to make modal dialog in WPF?

Did you try showing your window using the ShowDialog method?

Don't forget to set the Owner property on the dialog window to the main window. This will avoid weird behavior when Alt+Tabbing, etc.

How can I get the first two digits of a number?

Both of the previous 2 answers have at least O(n) time complexity and the string conversion has O(n) space complexity too. Here's a solution for constant time and space:

num // 10 ** (int(math.log(num, 10)) - 1)

Function:

import math

def first_n_digits(num, n):
    return num // 10 ** (int(math.log(num, 10)) - n + 1)

Output:

>>> first_n_digits(123456, 1)
1
>>> first_n_digits(123456, 2)
12
>>> first_n_digits(123456, 3)
123
>>> first_n_digits(123456, 4)
1234
>>> first_n_digits(123456, 5)
12345
>>> first_n_digits(123456, 6)
123456

You will need to add some checks if it's possible that your input number has less digits than you want.

ASP.NET Setting width of DataBound column in GridView

<asp:GridView ID="GridView1" AutoGenerateEditButton="True" 
ondatabound="gv_DataBound" runat="server" DataSourceID="SqlDataSource1"
AutoGenerateColumns="False" width="600px">

<Columns>
                <asp:BoundField HeaderText="UserId" 
                DataField="UserId" 
                SortExpression="UserId" ItemStyle-Width="400px"></asp:BoundField>
   </Columns>
</asp:GridView>

How to add a list item to an existing unordered list?

You should append to the container, not the last element:

$("#content ul").append('<li><a href="/user/messages"><span class="tab">Message Center</span></a></li>');

The append() function should've probably been called add() in jQuery because it sometimes confuses people. You would think it appends something after the given element, while it actually adds it to the element.

Check if an HTML input element is empty or has no value entered by user

Your first one was basically right. This, FYI, is bad. It does an equality check between a DOM node and a string:

if (document.getElementById('customx') == ""){

DOM nodes are actually their own type of JavaScript object. Thus this comparison would never work at all since it's doing an equality comparison on two distinctly different data types.

if else condition in blade file (laravel 5.3)

No curly braces required you can directly write

@if($user->status =='waiting')         
      <td><a href="#" class="viewPopLink btn btn-default1" role="button" data-id="{{ $user->travel_id }}" data-toggle="modal" data-target="#myModal">Approve/Reject<a></td>         
@else
      <td>{{ $user->status }}</td>        
@endif

how to automatically scroll down a html page?

here is the example using Pure JavaScript

_x000D_
_x000D_
function scrollpage() {  _x000D_
 function f() _x000D_
 {_x000D_
  window.scrollTo(0,i);_x000D_
  if(status==0) {_x000D_
      i=i+40;_x000D_
   if(i>=Height){ status=1; } _x000D_
  } else {_x000D_
   i=i-40;_x000D_
   if(i<=1){ status=0; }  // if you don't want continue scroll then remove this line_x000D_
  }_x000D_
 setTimeout( f, 0.01 );_x000D_
 }f();_x000D_
}_x000D_
var Height=document.documentElement.scrollHeight;_x000D_
var i=1,j=Height,status=0;_x000D_
scrollpage();_x000D_
</script>
_x000D_
<style type="text/css">_x000D_
_x000D_
 #top { border: 1px solid black;  height: 20000px; }_x000D_
 #bottom { border: 1px solid red; }_x000D_
_x000D_
</style>
_x000D_
<div id="top">top</div>_x000D_
<div id="bottom">bottom</div>
_x000D_
_x000D_
_x000D_

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

A few comments:

import sun.misc.*; Don't do this. It is non-standard and not guaranteed to be the same between implementations. There are other libraries with Base64 conversion available.

byte[] encVal = c.doFinal(Data.getBytes()); You are relying on the default character encoding here. Always specify what character encoding you are using: byte[] encVal = c.doFinal(Data.getBytes("UTF-8")); Defaults might be different in different places.

As @thegrinner pointed out, you need to explicitly check the length of your byte arrays. If there is a discrepancy, then compare them byte by byte to see where the difference is creeping in.

How can I make a link from a <td> table cell

I would recommend using an actual anchor element, and set it as block.

<div class="divBox">
    <a href="#">Link</a>
</div>

.divBox
{
    width: 300px;
    height: 100px;
}
.divBox a
{
    width: 100%;
    height: 100%;
    display: block;
}

This will set the anchor to the same dimensions of the parent div.

what is right way to do API call in react js?

I would like you to have a look at redux http://redux.js.org/index.html

They have very well defined way of handling async calls ie API calls, and instead of using jQuery for API calls, I would like to recommend using fetch or request npm packages, fetch is currently supported by modern browsers, but a shim is also available for server side.

There is also this another amazing package superagent, which has alot many options when making an API request and its very easy to use.

How to convert an object to a byte array in C#

To convert an object to a byte array:

// Convert an object to a byte array
public static byte[] ObjectToByteArray(Object obj)
{
    BinaryFormatter bf = new BinaryFormatter();
    using (var ms = new MemoryStream())
    {
        bf.Serialize(ms, obj);
        return ms.ToArray();
    }
}

You just need copy this function to your code and send to it the object that you need to convert to a byte array. If you need convert the byte array to an object again you can use the function below:

// Convert a byte array to an Object
public static Object ByteArrayToObject(byte[] arrBytes)
{
    using (var memStream = new MemoryStream())
    {
        var binForm = new BinaryFormatter();
        memStream.Write(arrBytes, 0, arrBytes.Length);
        memStream.Seek(0, SeekOrigin.Begin);
        var obj = binForm.Deserialize(memStream);
        return obj;
    }
}

You can use these functions with custom classes. You just need add the [Serializable] attribute in your class to enable serialization

1 = false and 0 = true?

It may very well be a mistake on the original author, however the notion that 1 is true and 0 is false is not a universal concept. In shell scripting 0 is returned for success, and any other number for failure. In other languages such as Ruby, only nil and false are considered false, and any other value is considered true, so in Ruby both 1 and 0 would be considered true.

Why is Python running my module when I import it, and how do I stop it?

Use the if __name__ == '__main__' idiom -- __name__ is a special variable whose value is '__main__' if the module is being run as a script, and the module name if it's imported. So you'd do something like

# imports
# class/function definitions
if __name__ == '__main__':
    # code here will only run when you invoke 'python main.py'

Jmeter - Run .jmx file through command line and get the summary report in a excel

This worked for me on mac os High sierra 10.13.6, java 8 64-bit, jmeter 4.0

$  jmeter -n --testfile /path/to/Test_Plan.jmx

Sample output:

Creating summariser <summary>
Created the tree successfully using ./src/test/jmeter/Test_Plan.jmx
Starting the test @ Fri Aug 24 17:18:18 PDT 2018 (1535156298333)
Waiting for possible Shutdown/StopTestNow/Heapdump message on port 4445
summary =     10 in 00:00:09 =    1.1/s Avg:  6666 Min:  1000 Max:  8950 Err:     
0 (0.00%)
Tidying up ...    @ Fri Aug 24 17:18:28 PDT 2018 (1535156308049)
... end of run

How to highlight text using javascript

We if you also want it to be highlighted on page load, there is a new way.

just add #:~:text=Highlight%20These

try accessing this link in a new tab

https://stackoverflow.com/questions/38588721#:~:text=Highlight%20a%20text

Using CMake with GNU Make: How can I see the exact commands?

When you run make, add VERBOSE=1 to see the full command output. For example:

cmake .
make VERBOSE=1

Or you can add -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON to the cmake command for permanent verbose command output from the generated Makefiles.

cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make

To reduce some possibly less-interesting output you might like to use the following options. The option CMAKE_RULE_MESSAGES=OFF removes lines like [ 33%] Building C object..., while --no-print-directory tells make to not print out the current directory filtering out lines like make[1]: Entering directory and make[1]: Leaving directory.

cmake -DCMAKE_RULE_MESSAGES:BOOL=OFF -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make --no-print-directory

Retrieve Button value with jQuery

Inspired by postpostmodern I have made this, to make .val() work throughout my javascript code:

jQuery(function($) {

    if($.browser.msie) {
        // Fixes a know issue, that buttons value is overwritten with the text

        // Someone with more jQuery experience can probably tell me
        // how not to polute jQuery.fn here:
        jQuery.fn._orig_val = jQuery.fn.val

        jQuery.fn.val = function(value) {
            var elem = $(this);
            var html
            if(elem.attr('type') == 'button') {
                // if button, hide button text while getting val()
                html = elem.html()
                elem.html('')
            }
            // Use original function
            var result = elem._orig_val(value);
            if(elem.attr('type') == 'button') {
                elem.html(html)
            }
            return result;
        }
    }
})

It does however, not solve the submit problem, solved by postpostmodern. Perhaps this could be included in postpostmodern's solution here: http://gist.github.com/251287

Angular 2 Dropdown Options Default Value

<select class="form-control" name='someting' [ngModel]="selectedWorkout" (ngModelChange)="updateWorkout($event)">
    <option value="{{workout.name}}" *ngFor="#workout of workouts">{{workout.name}}</option>
</select>

If you are using form there should be name field inside select tag.

All you need to do is just add value to the option tag.

selectedWorkout value should be "back" , and its done.

Compiling LaTex bib source

You have to run 'bibtex':

latex paper.tex
bibtex paper
latex paper.tex
latex paper.tex
dvipdf paper.dvi

How to check the function's return value if true or false

Wrong syntax. You can't compare a Boolean to a string like "false" or "true". In your case, just test it's inverse:

if(!ValidateForm()) { ...

You could test against the constant false, but it's rather ugly and generally frowned upon:

if(ValidateForm() == false) { ...

Pass correct "this" context to setTimeout callback?

NOTE: This won't work in IE

var ob = {
    p: "ob.p"
}

var p = "window.p";

setTimeout(function(){
    console.log(this.p); // will print "window.p"
},1000); 

setTimeout(function(){
    console.log(this.p); // will print "ob.p"
}.bind(ob),1000);

How do I change data-type of pandas data frame to string with a defined format?

I'm putting this in a new answer because no linebreaks / codeblocks in comments. I assume you want those nans to turn into a blank string? I couldn't find a nice way to do this, only do the ugly method:

s = pd.Series([1001.,1002.,None])
a = s.loc[s.isnull()].fillna('')
b = s.loc[s.notnull()].astype(int).astype(str)
result = pd.concat([a,b])

Combine two columns and add into one new column

Did you check the string concatenation function? Something like:

update table_c set column_a = column_b || column_c 

should work. More here

how to get GET and POST variables with JQuery?

If your $_GET is multidimensional, this might be what you're wanting:

var $_GET = {};
document.location.search.replace(/\??(?:([^=]+)=([^&]*)&?)/g, function () {
    function decode(s) {
            return decodeURIComponent(s.split("+").join(" "));
    }

    //handling for multidimensional arrays
    if(decode(arguments[1]).indexOf("[]") > 0){
        var newName = decode(arguments[1]).substring(0, decode(arguments[1]).length - 2);
        if(typeof $_GET[newName] == 'undefined'){
            $_GET[newName] = new Array();
        }
        $_GET[newName].push(decode(arguments[2]));
    }else{
        $_GET[decode(arguments[1])] = decode(arguments[2]);
    }
});

JUnit Eclipse Plugin?

Junit is included by default with Eclipse (at least the Java EE version I'm sure). You may just need to add the view to your perspective.

How to refer to Excel objects in Access VBA?

I dissent from both the answers. Don't create a reference at all, but use late binding:

  Dim objExcelApp As Object
  Dim wb As Object

  Sub Initialize()
    Set objExcelApp = CreateObject("Excel.Application")
  End Sub

  Sub ProcessDataWorkbook()
     Set wb = objExcelApp.Workbooks.Open("path to my workbook")
     Dim ws As Object
     Set ws = wb.Sheets(1)

     ws.Cells(1, 1).Value = "Hello"
     ws.Cells(1, 2).Value = "World"

     'Close the workbook
     wb.Close
     Set wb = Nothing
  End Sub

You will note that the only difference in the code above is that the variables are all declared as objects and you instantiate the Excel instance with CreateObject().

This code will run no matter what version of Excel is installed, while using a reference can easily cause your code to break if there's a different version of Excel installed, or if it's installed in a different location.

Also, the error handling could be added to the code above so that if the initial instantiation of the Excel instance fails (say, because Excel is not installed or not properly registered), your code can continue. With a reference set, your whole Access application will fail if Excel is not installed.

Android Studio-No Module

Try first in Android Studio:

File -> Sync Project with Gradle Files

How to use executables from a package installed locally in node_modules?

update: If you're on the recent npm (version >5.2)

You can use:

npx <command>

npx looks for command in .bin directory of your node_modules

old answer:

For Windows

Store the following in a file called npm-exec.bat and add it to your %PATH%

@echo off
set cmd="npm bin"
FOR /F "tokens=*" %%i IN (' %cmd% ') DO SET modules=%%i
"%modules%"\%*

Usage

Then you can use it like npm-exec <command> <arg0> <arg1> ...

For example

To execute wdio installed in local node_modules directory, do:

npm-exec wdio wdio.conf.js

i.e. it will run .\node_modules\.bin\wdio wdio.conf.js

What is the difference between ( for... in ) and ( for... of ) statements?

The for...in statement iterates over the enumerable properties of an object, in an arbitrary order. Enumerable properties are those properties whose internal [[Enumerable]] flag is set to true, hence if there is any enumerable property in the prototype chain, the for...in loop will iterate on those as well.

The for...of statement iterates over data that iterable object defines to be iterated over.

Example:

Object.prototype.objCustom = function() {}; 
Array.prototype.arrCustom = function() {};

let iterable = [3, 5, 7];

for (let i in iterable) {
  console.log(i); // logs: 0, 1, 2, "arrCustom", "objCustom"
}

for (let i in iterable) {
  if (iterable.hasOwnProperty(i)) {
    console.log(i); // logs: 0, 1, 2,
  }
}

for (let i of iterable) {
  console.log(i); // logs: 3, 5, 7
}

Like earlier, you can skip adding hasOwnProperty in for...of loops.

php create object without class

you can always use new stdClass(). Example code:

   $object = new stdClass();
   $object->property = 'Here we go';

   var_dump($object);
   /*
   outputs:

   object(stdClass)#2 (1) {
      ["property"]=>
      string(10) "Here we go"
    }
   */

Also as of PHP 5.4 you can get same output with:

$object = (object) ['property' => 'Here we go'];

How to convert a string to character array in c (or) how to extract a single char form string?

In C, a string is actually stored as an array of characters, so the 'string pointer' is pointing to the first character. For instance,

char myString[] = "This is some text";

You can access any character as a simple char by using myString as an array, thus:

char myChar = myString[6];
printf("%c\n", myChar); // Prints s

Hope this helps! David

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

In my situation, I was trying to run a java web service in Tomcat 7 via a connector in Eclipse. The app ran well when I deployed the war file to an instance of Tomcat 7 on my laptop. The app requires a jdbc type 2 driver for "IBM DB2 9.5". For some odd reason the connector in Eclispe could not see or use the paths in the IBM DB2 environment variables, to reach the dll files installed on my laptop as the jcc client. The error message either stated that it failed to find the db2jcct2 dll file or it failed to find the dependent libraries for that dll file. Ultimately, I deleted the connector and rebuilt it. Then it worked properly. I'm adding this solution here as documentation, because I failed to find this specific solution anywhere else.

How to skip a iteration/loop in while-loop

You don't need to skip the iteration, since the rest of it is in the else statement, it will only be executed if the condition is not true.

But if you really need to skip it, you can use the continue; statement.

Div width 100% minus fixed amount of pixels

I had a similar issue where I wanted a banner across the top of the screen that had one image on the left and a repeating image on the right to the edge of the screen. I ended up resolving it like so:

CSS:

.banner_left {
position: absolute;
top: 0px;
left: 0px;
width: 131px;
height: 150px;
background-image: url("left_image.jpg");
background-repeat: no-repeat;
}

.banner_right {
position: absolute;
top: 0px;
left: 131px;
right: 0px;
height: 150px;
background-image: url("right_repeating_image.jpg");
background-repeat: repeat-x;
background-position: top left;
}

The key was the right tag. I'm basically specifying that I want it to repeat from 131px in from the left to 0px from the right.

How to negate specific word in regex?

I wish to complement the accepted answer and contribute to the discussion with my late answer.

@ChrisVanOpstal shared this regex tutorial which is a great resource for learning regex.

However, it was really time consuming to read through.

I made a cheatsheet for mnemonic convenience.

This reference is based on the braces [], (), and {} leading each class, and I find it easy to recall.

Regex = {
 'single_character': ['[]', '.', {'negate':'^'}],
 'capturing_group' : ['()', '|', '\\', 'backreferences and named group'],
 'repetition'      : ['{}', '*', '+', '?', 'greedy v.s. lazy'],
 'anchor'          : ['^', '\b', '$'],
 'non_printable'   : ['\n', '\t', '\r', '\f', '\v'],
 'shorthand'       : ['\d', '\w', '\s'],
 }

Server is already running in Rails

TL;DR Just Run this command to Kill it

sudo kill -9 $(lsof -i :3000 -t)

Root Cause: Because PID is locked in a file and web server thinks that if that file exists then it means it is already running. Normally when a web server is closed that file is deleted, but in some cases, proper deletion doesn't happen so you have to remove the file manually New Solutions

when you run rails s

=> Booting WEBrick

=> Rails 4.0.4 application starting in development on http://0.0.0.0:3000

=> Run rails server -h for more startup options

=> Ctrl-C to shutdown server

A server is already running. Check /your_project_path/tmp/pids/server.pid. Exiting

So place your path shown here /your_project_path/tmp/pids/server.pid

and remove this server.pid file:

rm /your_project_path/tmp/pids/server.pid

OR Incase you're server was detached then follow below guidelines:

If you detached you rails server by using command "rails -d" then,

Remove rails detached server by using command

ps -aef | grep rails

OR by this command

sudo lsof -wni tcp:3000

then

kill -9 pID

OR use this command

To find and kill process by port name on which that program is running. For 3000 replace port on which your program is running.

sudo kill -9 $(lsof -i :3000 -t)

Old Solution:

rails s -p 4000 -P tmp/pids/server2.pid

Also you can find this post for more options Rails Update to 3.2.11 breaks running multiple servers

LISTAGG in Oracle to return distinct values

If you do not need a particular order of concatenated values, and the separator can be a comma, you can do:

select col1, stragg(distinct col2)
  from table
 group by col1

Create a string with n characters

You can use standard String.format function for generate N spaces. For example:

String.format("%5c", ' ');

Makes a string with 5 spaces.

or

int count = 15;
String fifteenSpacebars = String.format("%" + count + "c", ' ');

Makes a string of 15 spacebars.

If you want another symbol to repeat, you must replace spaces with your desired symbol:

int count = 7;
char mySymbol = '#';
System.out.println(String.format("%" + count + "c", ' ').replaceAll("\\ ", "\\" + mySymbol));

Output:

#######

Printf width specifier to maintain precision of floating-point value

I run a small experiment to verify that printing with DBL_DECIMAL_DIG does indeed exactly preserve the number's binary representation. It turned out that for the compilers and C libraries I tried, DBL_DECIMAL_DIG is indeed the number of digits required, and printing with even one digit less creates a significant problem.

#include <float.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

union {
    short s[4];
    double d;
} u;

void
test(int digits)
{
    int i, j;
    char buff[40];
    double d2;
    int n, num_equal, bin_equal;

    srand(17);
    n = num_equal = bin_equal = 0;
    for (i = 0; i < 1000000; i++) {
        for (j = 0; j < 4; j++)
            u.s[j] = (rand() << 8) ^ rand();
        if (isnan(u.d))
            continue;
        n++;
        sprintf(buff, "%.*g", digits, u.d);
        sscanf(buff, "%lg", &d2);
        if (u.d == d2)
            num_equal++;
        if (memcmp(&u.d, &d2, sizeof(double)) == 0)
            bin_equal++;
    }
    printf("Tested %d values with %d digits: %d found numericaly equal, %d found binary equal\n", n, digits, num_equal, bin_equal);
}

int
main()
{
    test(DBL_DECIMAL_DIG);
    test(DBL_DECIMAL_DIG - 1);
    return 0;
}

I run this with Microsoft's C compiler 19.00.24215.1 and gcc version 7.4.0 20170516 (Debian 6.3.0-18+deb9u1). Using one less decimal digit halves the number of numbers that compare exactly equal. (I also verified that rand() as used indeed produces about one million different numbers.) Here are the detailed results.

Microsoft C

Tested 999507 values with 17 digits: 999507 found numericaly equal, 999507 found binary equal
Tested 999507 values with 16 digits: 545389 found numericaly equal, 545389 found binary equal

GCC

Tested 999485 values with 17 digits: 999485 found numericaly equal, 999485 found binary equal
Tested 999485 values with 16 digits: 545402 found numericaly equal, 545402 found binary equal

Bootstrap 3 - jumbotron background image effect

After inspecting the sample website you provided, I found that the author might achieve the effect by using a library called Stellar.js, take a look at the library site, cheers!

check / uncheck checkbox using jquery?

For jQuery 1.6+ :

.attr() is deprecated for properties; use the new .prop() function instead as:

$('#myCheckbox').prop('checked', true); // Checks it
$('#myCheckbox').prop('checked', false); // Unchecks it

For jQuery < 1.6:

To check/uncheck a checkbox, use the attribute checked and alter that. With jQuery you can do:

$('#myCheckbox').attr('checked', true); // Checks it
$('#myCheckbox').attr('checked', false); // Unchecks it

Cause you know, in HTML, it would look something like:

<input type="checkbox" id="myCheckbox" checked="checked" /> <!-- Checked -->
<input type="checkbox" id="myCheckbox" /> <!-- Unchecked -->

However, you cannot trust the .attr() method to get the value of the checkbox (if you need to). You will have to rely in the .prop() method.

Add a duration to a moment (moment.js)

I am working on an application in which we track live route. Passenger wants to show current position of driver and the expected arrival time to reach at his/her location. So I need to add some duration into current time.

So I found the below mentioned way to do the same. We can add any duration(hour,minutes and seconds) in our current time by moment:

var travelTime = moment().add(642, 'seconds').format('hh:mm A');// it will add 642 seconds in the current time and will give time in 03:35 PM format

var travelTime = moment().add(11, 'minutes').format('hh:mm A');// it will add 11 mins in the current time and will give time in 03:35 PM format; can use m or minutes 

var travelTime = moment().add(2, 'hours').format('hh:mm A');// it will add 2 hours in the current time and will give time in 03:35 PM format

It fulfills my requirement. May be it can help you.

How can I do time/hours arithmetic in Google Spreadsheet?

Type the values in single cells, because google spreadsheet cant handle duration formats at all, in any way shape or form. Or you have to learn to make scripts and graduate as a chopper pilot. that is also a option.

return value after a promise

The best way to do this would be to use the promise returning function as it is, like this

lookupValue(file).then(function(res) {
    // Write the code which depends on the `res.val`, here
});

The function which invokes an asynchronous function cannot wait till the async function returns a value. Because, it just invokes the async function and executes the rest of the code in it. So, when an async function returns a value, it will not be received by the same function which invoked it.

So, the general idea is to write the code which depends on the return value of an async function, in the async function itself.

Scroll Position of div with "overflow: auto"

You need to use the scrollTop property.

document.getElementById('box').scrollTop

Export from pandas to_excel without row names (index)?

You need to set index=False in to_excel in order for it to not write the index column out, this semantic is followed in other Pandas IO tools, see http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.to_excel.html and http://pandas.pydata.org/pandas-docs/stable/io.html

Concatenating Matrices in R

Sounds like you're looking for rbind:

> a<-matrix(nrow=10,ncol=5)
> b<-matrix(nrow=20,ncol=5)
> dim(rbind(a,b))
[1] 30  5

Similarly, cbind stacks the matrices horizontally.

I am not entirely sure what you mean by the last question ("Can I do this for matrices of different rows and columns.?")

Switch on ranges of integers in JavaScript

If you need check ranges you are probably better off with if and else if statements, like so:

if (range > 0 && range < 5)
{
    // ..
}
else if (range > 5 && range < 9)
{
    // ..
}
else
{
    // Fall through
}

A switch could get large on bigger ranges.

how to convert integer to string?

NSArray *myArray = [NSArray arrayWithObjects:[NSNumber numberWithInt:1], [NSNumber numberWithInt:2], [NSNumber numberWithInt:3]];

Update for new Objective-C syntax:

NSArray *myArray = @[@1, @2, @3];

Those two declarations are identical from the compiler's perspective.

if you're just wanting to use an integer in a string for putting into a textbox or something:

int myInteger = 5;
NSString* myNewString = [NSString stringWithFormat:@"%i", myInteger];

How to get the number of characters in a std::string?

It might be the easiest way to input a string and find its length.

// Finding length of a string in C++ 
#include<iostream>
#include<string>
using namespace std;

int count(string);

int main()
{
string str;
cout << "Enter a string: ";
getline(cin,str);
cout << "\nString: " << str << endl;
cout << count(str) << endl;

return 0;

}

int count(string s){
if(s == "")
  return 0;
if(s.length() == 1)
  return 1;
else
    return (s.length());

}

jQuery Screen Resolution Height Adjustment

var space = $(window).height();
var diff = space - HEIGHT;
var margin = (diff > 0) ? (space - HEIGHT)/2 : 0;
$('#container').css({'margin-top': margin});

A warning - comparison between signed and unsigned integer expressions

It is usually a good idea to declare variables as unsigned or size_t if they will be compared to sizes, to avoid this issue. Whenever possible, use the exact type you will be comparing against (for example, use std::string::size_type when comparing with a std::string's length).

Compilers give warnings about comparing signed and unsigned types because the ranges of signed and unsigned ints are different, and when they are compared to one another, the results can be surprising. If you have to make such a comparison, you should explicitly convert one of the values to a type compatible with the other, perhaps after checking to ensure that the conversion is valid. For example:

unsigned u = GetSomeUnsignedValue();
int i = GetSomeSignedValue();

if (i >= 0)
{
    // i is nonnegative, so it is safe to cast to unsigned value
    if ((unsigned)i >= u)
        iIsGreaterThanOrEqualToU();
    else
        iIsLessThanU();
}
else
{
    iIsNegative();
}

jQuery UI DatePicker to show month year only

I had the problem of date picker mixed with month picker. I solved it like that.

    $('.monthpicker').focus(function()
    {
    $(".ui-datepicker-calendar").show();
    }).datepicker( {
        changeMonth: true,
        changeYear: true,
        showButtonPanel: true,
        dateFormat: 'MM/yy',
        create: function (input, inst) { 

         },
        onClose: function(dateText, inst) { 
            var month = 1+parseInt($("#ui-datepicker-div .ui-datepicker-month :selected").val());           
            var year = $("#ui-datepicker-div .ui-datepicker-year :selected").val();

        }
    });

TypeScript: Creating an empty typed container array

For publicly access use like below:

public arr: Criminal[] = [];

What's the difference between emulation and simulation?

Based on software and system engineering experience, I'd summarise the difference as follows:

Simulation: for me, this is always in software - every aspect of the real system is only MODELLED by some code and/or mathematics. Simulation attempts to accurately reproduce the behaviour (or predict it) of the real system, but only approximates it.

Emulation: As opposed to simulation, it does not APPROXIMATE the behaviour of the real system, it COPIES the behaviour of the real system. An emulator may involve hardware. But it may also be entirely in software. E.g. you get these software EMULATORS for old game consoles like the Sega Genesis. That is an emulator because it COPIES the real genesis functionality so much so that you can run the original Genesis code in the emulator. A genesis simulator would not be able to run the original code, it would only APPROXIMATE its behaviour, producing similar results, depending on how good the models of the original system were.

An emulator of a system component can be included in a larger system, completely replacing the component it is emulating - a simulator could not because it is not an accurate enough representation of the original component behaviour.

Xcode 6: Keyboard does not show up in simulator

In the new simulator Hardware option is removed,

If you want to find a Keyboard option manually, Then click on the I/O section,

I/O -> Keyboard ->Toggle Software Keyboard(?K)

enter image description here

Get my phone number in android

As Answered here

Use below code :

TelephonyManager tMgr = (TelephonyManager)mAppContext.getSystemService(Context.TELEPHONY_SERVICE);
String mPhoneNumber = tMgr.getLine1Number();

In AndroidManifest.xml, give the following permission:

 <uses-permission android:name="android.permission.READ_PHONE_STATE"/> 

But remember, this code does not always work, since Cell phone number is dependent on the SIM Card and the Network operator / Cell phone carrier.

Also, try checking in Phone--> Settings --> About --> Phone Identity, If you are able to view the Number there, the probability of getting the phone number from above code is higher. If you are not able to view the phone number in the settings, then you won't be able to get via this code!

Suggested Workaround:

  1. Get the user's phone number as manual input from the user.
  2. Send a code to the user's mobile number via SMS.
  3. Ask user to enter the code to confirm the phone number.
  4. Save the number in sharedpreference.

Do the above 4 steps as one time activity during the app's first launch. Later on, whenever phone number is required, use the value available in shared preference.

HTTP Status 405 - Method Not Allowed Error for Rest API

@Produces({"text/plain","application/xml","application/json"}) change this to @Produces("text/plain") and try,

ASP.NET MVC DropDownListFor with model of type List<string>

To make a dropdown list you need two properties:

  1. a property to which you will bind to (usually a scalar property of type integer or string)
  2. a list of items containing two properties (one for the values and one for the text)

In your case you only have a list of string which cannot be exploited to create a usable drop down list.

While for number 2. you could have the value and the text be the same you need a property to bind to. You could use a weakly typed version of the helper:

@model List<string>
@Html.DropDownList(
    "Foo", 
    new SelectList(
        Model.Select(x => new { Value = x, Text = x }),
        "Value",
        "Text"
    )
)

where Foo will be the name of the ddl and used by the default model binder. So the generated markup might look something like this:

<select name="Foo" id="Foo">
    <option value="item 1">item 1</option>
    <option value="item 2">item 2</option>
    <option value="item 3">item 3</option>
    ...
</select>

This being said a far better view model for a drop down list is the following:

public class MyListModel
{
    public string SelectedItemId { get; set; }
    public IEnumerable<SelectListItem> Items { get; set; }
}

and then:

@model MyListModel
@Html.DropDownListFor(
    x => x.SelectedItemId,
    new SelectList(Model.Items, "Value", "Text")
)

and if you wanted to preselect some option in this list all you need to do is to set the SelectedItemId property of this view model to the corresponding Value of some element in the Items collection.

Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0

For me the cause was incorrect url for jcenter. To solve it I simply changed url for app and proect level build.gradle

from

jcenter { url "http://jcenter.bintray.com/"}

to

jcenter()

AngularJs: Reload page

This can be done by calling the reload() method of the window object in plain JavaScript

window.location.reload();

How to install pandas from pip on windows cmd?

Since both pip nor python commands are not installed along Python in Windows, you will need to use the Windows alternative py, which is included by default when you installed Python. Then you have the option to specify a general or specific version number after the py command.

C:\> py      -m pip install pandas  %= one of Python on the system =%
C:\> py -2   -m pip install pandas  %= one of Python 2 on the system =%
C:\> py -2.7 -m pip install pandas  %= only for Python 2.7 =%
C:\> py -3   -m pip install pandas  %= one of Python 3 on the system =%
C:\> py -3.6 -m pip install pandas  %= only for Python 3.6 =%

Alternatively, in order to get pip to work without py -m part, you will need to add pip to the PATH environment variable.

C:\> setx PATH "%PATH%;C:\<path\to\python\folder>\Scripts"

Now you can run the following command as expected.

C:\> pip install pandas

Troubleshooting:


Problem:

connection error: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed

Solution:

This is caused by your SSL certificate is unable to verify the host server. You can add pypi.python.org to the trusted host or specify an alternative SSL certificate. For more information, please see this post. (Thanks to Anuj Varshney for suggesting this)

C:\> py -m pip install --trusted-host pypi.python.org pip pandas

Problem:

PermissionError: [WinError 5] Access is denied

Solution:

This is a caused by when you don't permission to modify the Python site-package folders. You can avoid this with one of the following methods:

  • Run Windows Command Prompt as administrator (thanks to DataGirl's suggestion) by:

    1. Windows-Key + R to open run
    2. type in cmd.exe in the search box
    3. CTRL + SHIFT + ENTER
    4. An alternative method for step 1-3 would be to manually locate cmd.exe, right click, then click Run as Administrator.
  • Run pip in user mode by adding --user option when installing with pip. Which typically install the package to the local %APPDATA% Python folder.

C:\> py -m pip install --user pandas
C:\> py -m venv c:\path\to\new\venv
C:\> <path\to\the\new\venv>\Scripts\activate.bat

How do I rename the android package name?

I found a good work around for this problem. Taking the example mentioned in the question, following are the steps for changing the package name from com.example.test to com.example2.test :

  1. create a temporary directory, say temp inside the directory example (alongside directory test).
  2. Go back to the Intellij project, select the folder com.example and Click Shift + F6. Now it offers to rename the text example. Here you can enter the new text you want and IntelliJ will do the rest for you.
  3. Delete the temporary directory temp from the file system.

This idea can be used to refactor any part of the package name.

Good luck!!

How can I change text color via keyboard shortcut in MS word 2010

You could use a macro, but it’s simpler to use styles. Define a character style that has the desired text color and assign a shortcut key to it, say Alt+R. In order to be able to switch color using just the keyboard, define another character style, say “normal”, that has no special feature—just for use to get normal text after switching to your colored style, and assign another shortcut to it, say Alt+N. Then you would just type text, press Alt+R to switch to colored text, type that text, press Alt+N to resume normal text color, etc.

How to set HTTP headers (for cache-control)?

To use cache-control in HTML, you use the meta tag, e.g.

<meta http-equiv="Cache-control" content="public">

The value in the content field is defined as one of the four values below.

Some information on the Cache-Control header is as follows

HTTP 1.1. Allowed values = PUBLIC | PRIVATE | NO-CACHE | NO-STORE.

Public - may be cached in public shared caches.
Private - may only be cached in private cache.
No-Cache - may not be cached.
No-Store - may be cached but not archived.

The directive CACHE-CONTROL:NO-CACHE indicates cached information should not be used and instead requests should be forwarded to the origin server. This directive has the same semantics as the PRAGMA:NO-CACHE.

Clients SHOULD include both PRAGMA: NO-CACHE and CACHE-CONTROL: NO-CACHE when a no-cache request is sent to a server not known to be HTTP/1.1 compliant. Also see EXPIRES.

Note: It may be better to specify cache commands in HTTP than in META statements, where they can influence more than the browser, but proxies and other intermediaries that may cache information.

Excel VBA Automation Error: The object invoked has disconnected from its clients

I had this same problem in a large Excel 2000 spreadsheet with hundreds of lines of code. My solution was to make the Worksheet active at the beginning of the Class. I.E. ThisWorkbook.Worksheets("WorkSheetName").Activate This was finally discovered when I noticed that if "WorkSheetName" was active when starting the operation (the code) the error didn't occur. Drove me crazy for quite awhile.

How to check if variable's type matches Type stored in a variable

The other answers all contain significant omissions.

The is operator does not check if the runtime type of the operand is exactly the given type; rather, it checks to see if the runtime type is compatible with the given type:

class Animal {}
class Tiger : Animal {}
...
object x = new Tiger();
bool b1 = x is Tiger; // true
bool b2 = x is Animal; // true also! Every tiger is an animal.

But checking for type identity with reflection checks for identity, not for compatibility

bool b5 = x.GetType() == typeof(Tiger); // true
bool b6 = x.GetType() == typeof(Animal); // false! even though x is an animal

or with the type variable
bool b7 = t == typeof(Tiger); // true
bool b8 = t == typeof(Animal); // false! even though x is an 

If that's not what you want, then you probably want IsAssignableFrom:

bool b9 = typeof(Tiger).IsAssignableFrom(x.GetType()); // true
bool b10 = typeof(Animal).IsAssignableFrom(x.GetType()); // true! A variable of type Animal may be assigned a Tiger.

or with the type variable
bool b11 = t.IsAssignableFrom(x.GetType()); // true
bool b12 = t.IsAssignableFrom(x.GetType()); // true! A 

How to get the integer value of day of week

If you want to set first day of the week to Monday with integer value 1 and Sunday with integer value 7

int day = ((int)DateTime.Now.DayOfWeek == 0) ? 7 : (int)DateTime.Now.DayOfWeek;

What is MATLAB good for? Why is it so used by universities? When is it better than Python?

Matlab is good at doing number crunching. Also Matrix and matrix manipulation. It has many helpful built in libraries(depends on the what version) I think it is easier to use than python if you are going to be calculating equations.

Meaning of delta or epsilon argument of assertEquals for double values

Epsilon is the value that the 2 numbers can be off by. So it will assert to true as long as Math.abs(expected - actual) < epsilon

How to update Xcode from command line

I was facing the same problem, resolved it by using the following command.

sudo xcode-select -s /Library/Developer/CommandLineTools

After running the above command then xcode-select -p command showed the following.

/Library/Developer/CommandLineTools

Datatables - Search Box outside datatable

This one helped me for DataTables Version 1.10.4, because its new API

var oTable = $('#myTable').DataTable();    
$('#myInputTextField').keyup(function(){
   oTable.search( $(this).val() ).draw();
})

How do you specify a debugger program in Code::Blocks 12.11?

Click on settings in top tool bar;

Click on debugger;

In tree, highlight "gdb/cdb debugger" by clicking it

Click "create configuration"

Click default configuration, a dialogue will appear to the right for "executable path" with a button to the right.

Click on that button and it will bring up the file that codeblocks is installed in. Just keep clicking until you create the path to the gdb.exe (it sort of finds itself).

How to use setprecision in C++

#include <bits/stdc++.h>                        // to include all libraries 
using namespace std; 
int main() 
{ 
double a,b;
cin>>a>>b;
double x=a/b;                                 //say we want to divide a/b                                 
cout<<fixed<<setprecision(10)<<x;             //for precision upto 10 digit 
return 0; 
} 

input: 1987 31

output: 662.3333333333 10 digits after decimal point

How to define Typescript Map of key value pair. where key is a number and value is an array of objects

The most simple way is to use Record type Record<number, productDetails >

interface productDetails {
   productId : number , 
   price : number , 
   discount : number
};

const myVar : Record<number, productDetails> = {
   1: {
       productId : number , 
       price : number , 
       discount : number
   }
}

Is there a foreach loop in Go?

The following example shows how to use the range operator in a for loop to implement a foreach loop.

func PrintXml (out io.Writer, value interface{}) error {
    var data []byte
    var err error

    for _, action := range []func() {
        func () { data, err = xml.MarshalIndent(value, "", "  ") },
        func () { _, err = out.Write([]byte(xml.Header)) },
        func () { _, err = out.Write(data) },
        func () { _, err = out.Write([]byte("\n")) }} {
        action();
        if err != nil {
            return err
        }
    }
    return nil;
}

The example iterates over an array of functions to unify the error handling for the functions. A complete example is at Google´s playground.

PS: it shows also that hanging braces are a bad idea for the readability of code. Hint: the for condition ends just before the action() call. Obvious, isn't it?

Does Python's time.time() return the local or UTC timestamp?

I eventually settled for:

>>> import time
>>> time.mktime(time.gmtime())
1509467455.0

Insert current date into a date column using T-SQL?

To insert a new row into a given table (tblTable) :

INSERT INTO tblTable (DateColumn) VALUES (GETDATE())

To update an existing row :

UPDATE tblTable SET DateColumn = GETDATE()
 WHERE ID = RequiredUpdateID

Note that when INSERTing a new row you will need to observe any constraints which are on the table - most likely the NOT NULL constraint - so you may need to provide values for other columns eg...

 INSERT INTO tblTable (Name, Type, DateColumn) VALUES ('John', 7, GETDATE())

Print in one line dynamically

In Python 3 you can do it this way:

for item in range(1,10):
    print(item, end =" ")

Outputs:

1 2 3 4 5 6 7 8 9 

Tuple: You can do the same thing with a tuple:

tup = (1,2,3,4,5)

for n in tup:
    print(n, end = " - ")

Outputs:

1 - 2 - 3 - 4 - 5 - 

Another example:

list_of_tuples = [(1,2),('A','B'), (3,4), ('Cat', 'Dog')]
for item in list_of_tuples:
    print(item)

Outputs:

(1, 2)
('A', 'B')
(3, 4)
('Cat', 'Dog')

You can even unpack your tuple like this:

list_of_tuples = [(1,2),('A','B'), (3,4), ('Cat', 'Dog')]

# Tuple unpacking so that you can deal with elements inside of the tuple individually
for (item1, item2) in list_of_tuples:
    print(item1, item2)   

Outputs:

1 2
A B
3 4
Cat Dog

another variation:

list_of_tuples = [(1,2),('A','B'), (3,4), ('Cat', 'Dog')]
for (item1, item2) in list_of_tuples:
    print(item1)
    print(item2)
    print('\n')

Outputs:

1
2


A
B


3
4


Cat
Dog

The most sophisticated way for creating comma-separated Strings from a Collection/Array/List?

String.join(", ", collectionOfStrings)

available in the Java8 api.

alternative to (without the need to add a google guava dependency):

Joiner.on(",").join(collectionOfStrings);

How to display string that contains HTML in twig template?

You can also use:

{{ word|striptags('<b>')|raw }}

so that only <b> tag will be allowed.

Get size of folder or file

I've tested du -c <folderpath> and is 2x faster than nio.Files or recursion

private static long getFolderSize(File folder){
  if (folder != null && folder.exists() && folder.canRead()){
    try {
      Process p = new ProcessBuilder("du","-c",folder.getAbsolutePath()).start();
      BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
      String total = "";
      for (String line; null != (line = r.readLine());)
        total = line;
      r.close();
      p.waitFor();
      if (total.length() > 0 && total.endsWith("total"))
        return Long.parseLong(total.split("\\s+")[0]) * 1024;
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }
  return -1;
}

How do I print out the value of this boolean? (Java)

you should just remove the 'boolean' in front of your boolean variable.

Do it like this:

boolean isLeapYear = true;
System.out.println(isLeapYear);

or

boolean isLeapYear = true;
System.out.println(isLeapYear?"yes":"no");

The other thing ist hat you seems not to call the method at all! The method and the variable are both not static, thus, you have to create an instance of your class first. Or you just make both static and than simply call your method directly from your maim method.

Thus there are a couple of mistakes in the code. May be you shoud start with a more simple example and than rework it until it does what you want.

Example:

import java.util.Scanner;

public class booleanfun    {
    static boolean isLeapYear;

    public static void main(String[] args)
    {
        System.out.println("Enter a year to determine if it is a leap year or not: ");
        Scanner kboard = new Scanner(System.in);
        int year = kboard.nextInt();
        isLeapYear(year);
    }
    public static boolean isLeapYear(int year) {
        if (year % 4 != 0)
        isLeapYear = false;

        else if ((year % 4 == 0) && (year % 100 == 0))

        isLeapYear = false;

        else if ((year % 4 == 0) && (year % 100 == 0) && (year % 400 == 0))
            isLeapYear = true;

        else
            isLeapYear = false;

        System.out.println(isLeapYear);

        return isLeapYear;
    }
}

SQL select everything in an array

SELECT * FROM products WHERE catid IN ('1', '2', '3', '4')

In what cases will HTTP_REFERER be empty

It will also be empty if the new Referrer Policy standard draft is used to prevent that the referer header is sent to the request origin. Example:

<meta name="referrer" content="none">

Although Chrome and Firefox have already implemented a draft version of the Referrer Policy, you should be careful with it because for example Chrome expects no-referrer instead of none (and I have seen also never somewhere).

Best way to get child nodes

Sounds like you're overthinking it. You've observed the difference between childNodes and children, which is that childNodes contains all nodes, including text nodes consisting entirely of whitespace, while children is a collection of just the child nodes that are elements. That's really all there is to it.

There is nothing unpredictable about either collection, although there are a couple of issues to be aware of:

  • IE <= 8 do not include white space-only text nodes in childNodes while other browsers do
  • IE <= 8 includes comment nodes within children while other browsers only have elements

children, firstElementChild and friends are just conveniences, presenting a filtered view of the DOM restricted to just elements.

How to correctly use "section" tag in HTML5?

In the W3 wiki page about structuring HTML5, it says:

<section>: Used to either group different articles into different purposes or subjects, or to define the different sections of a single article.

And then displays an image that I cleaned up:

enter image description here

It's also important to know how to use the <article> tag (from the same W3 link above):

<article> is related to <section>, but is distinctly different. Whereas <section> is for grouping distinct sections of content or functionality, <article> is for containing related individual standalone pieces of content, such as individual blog posts, videos, images or news items. Think of it this way - if you have a number of items of content, each of which would be suitable for reading on their own, and would make sense to syndicate as separate items in an RSS feed, then <article> is suitable for marking them up.

In our example, <section id="main"> contains blog entries. Each blog entry would be suitable for syndicating as an item in an RSS feed, and would make sense when read on its own, out of context, therefore <article> is perfect for them:

<section id="main">
    <article>
      <!-- first blog post -->
    </article>

    <article>
      <!-- second blog post  -->
    </article>

    <article>
      <!-- third blog post -->
    </article>
</section>

Simple huh? Be aware though that you can also nest sections inside articles, where it makes sense to do so. For example, if each one of these blog posts has a consistent structure of distinct sections, then you could put sections inside your articles as well. It could look something like this:

<article>
  <section id="introduction">
  </section>

  <section id="content">
  </section>

  <section id="summary">
  </section>
</article>

Generating a SHA-256 hash from the Linux command line

I believe that echo outputs a trailing newline. Try using -n as a parameter to echo to skip the newline.

How to loop through all but the last item of a list?

If you want to get all the elements in the sequence pair wise, use this approach (the pairwise function is from the examples in the itertools module).

from itertools import tee, izip, chain

def pairwise(seq):
    a,b = tee(seq)
    b.next()
    return izip(a,b)

for current_item, next_item in pairwise(y):
    if compare(current_item, next_item):
        # do what you have to do

If you need to compare the last value to some special value, chain that value to the end

for current, next_item in pairwise(chain(y, [None])):

How to get back Lost phpMyAdmin Password, XAMPP

Hi this worked for me "/opt/lampp/xampp security" in Centos

[root@XXXXX ~]# /opt/lampp/xampp security

XAMPP: Quick security check...

XAMPP: Your XAMPP pages are secured by a password.

XAMPP: Do you want to change the password anyway? [no] yes

XAMPP: Password:

XAMPP: Password (again):

XAMPP: Password protection active. Please use 'xampp' as user name!

XAMPP: MySQL is not accessable via network. Good.

XAMPP: MySQL has a root passwort set. Fine! :)

XAMPP: The FTP password for user 'daemon' is still set to 'xampp'.

XAMPP: Do you want to change the password? [yes]

XAMPP: Password:

XAMPP: Password (again):

XAMPP: Reload ProFTPD...ok.

XAMPP: Done.

[root@XXXXX ~]#

Python: 'break' outside loop

Because break can only be used inside a loop. It is used to break out of a loop (stop the loop).

set height of imageview as matchparent programmatically

You can use the MATCH_PARENT constant or its numeric value -1.

Numeric for loop in Django templates

Maybe like this?

{% for i in "x"|rjust:"100" %}
...
{% endfor %}

Oracle - How to create a readonly user

you can create user and grant privilege

create user read_only identified by read_only; grant create session,select any table to read_only;

Converting a string to an integer on Android

See the Integer class and the static parseInt() method:

http://developer.android.com/reference/java/lang/Integer.html

Integer.parseInt(et.getText().toString());

You will need to catch NumberFormatException though in case of problems whilst parsing, so:

int myNum = 0;

try {
    myNum = Integer.parseInt(et.getText().toString());
} catch(NumberFormatException nfe) {
   System.out.println("Could not parse " + nfe);
} 

SQL Inner join more than two tables

select * from Employee inner join [Order] 
On Employee.Employee_id=[Order].Employee_id
inner join Book 
On Book.Book_id=[Order].Book_id
inner join Book_Author
On Book_Author.Book_id=Book.Book_id
inner join Author
On Book_Author.Author_id=Author.Author_id;

multiple plot in one figure in Python

Since I don't have a high enough reputation to comment I'll answer liang question on Feb 20 at 10:01 as an answer to the original question.

In order for the for the line labels to show you need to add plt.legend to your code. to build on the previous example above that also includes title, ylabel and xlabel:

import matplotlib.pyplot as plt

plt.plot(<X AXIS VALUES HERE>, <Y AXIS VALUES HERE>, 'line type', label='label here')
plt.plot(<X AXIS VALUES HERE>, <Y AXIS VALUES HERE>, 'line type', label='label here')
plt.title('title')
plt.ylabel('ylabel')
plt.xlabel('xlabel')
plt.legend()
plt.show()

How do I deal with special characters like \^$.?*|+()[{ in my regex?

I think the easiest way to match the characters like

\^$.?*|+()[

are using character classes from within R. Consider the following to clean column headers from a data file, which could contain spaces, and punctuation characters:

> library(stringr)
> colnames(order_table) <- str_replace_all(colnames(order_table),"[:punct:]|[:space:]","")

This approach allows us to string character classes to match punctation characters, in addition to whitespace characters, something you would normally have to escape with \\ to detect. You can learn more about the character classes at this cheatsheet below, and you can also type in ?regexp to see more info about this.

https://www.rstudio.com/wp-content/uploads/2016/09/RegExCheatsheet.pdf

Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2:java (default-cli)

To solve this problem in IntelliJ...
1) Put your .fxml files into resources directory
2) In the Start method define the path to .fxml file in the following way:
Parent root = FXMLLoader.load(getClass().getResource("/sample.fxml"));
The / seemed to solve this problem for me :)

How to avoid pressing Enter with getchar() for reading a single character only?

yes you can do this on windows too, here's the code below, using the conio.h library

#include <iostream> //basic input/output
#include <conio.h>  //provides non standard getch() function
using namespace std;

int main()
{  
  cout << "Password: ";  
  string pass;
  while(true)
  {
             char ch = getch();    

             if(ch=='\r'){  //when a carriage return is found [enter] key
             cout << endl << "Your password is: " << pass <<endl; 
             break;
             }

             pass+=ch;             
             cout << "*";
             }
  getch();
  return 0;
}

How can I directly view blobs in MySQL Workbench

I pieced a few of the other posts together, as the workbench 'preferences' fix did not work for me. (WB 6.3)

SELECT CAST(`column` AS CHAR(10000) CHARACTER SET utf8) FROM `table`;

How to implement if-else statement in XSLT?

If I may offer some suggestions (two years later but hopefully helpful to future readers):

  • Factor out the common h2 element.
  • Factor out the common ooooooooooooo text.
  • Be aware of new XPath 2.0 if/then/else construct if using XSLT 2.0.

XSLT 1.0 Solution (also works with XSLT 2.0)

<h2>
  <xsl:choose>
    <xsl:when test="$CreatedDate > $IDAppendedDate">m</xsl:when>
    <xsl:otherwise>d</xsl:otherwise>
  </xsl:choose>
  ooooooooooooo
</h2>

XSLT 2.0 Solution

<h2>
   <xsl:value-of select="if ($CreatedDate > $IDAppendedDate) then 'm' else 'd'"/>
   ooooooooooooo
</h2>

Convert 24 Hour time to 12 Hour plus AM/PM indication Oracle SQL

For the 24-hour time, you need to use HH24 instead of HH.

For the 12-hour time, the AM/PM indicator is written as A.M. (if you want periods in the result) or AM (if you don't). For example:

SELECT invoice_date,
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH24:MI:SS') "Date 24Hr",
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH:MI:SS AM') "Date 12Hr"
  FROM invoices
;

For more information on the format models you can use with TO_CHAR on a date, see http://docs.oracle.com/cd/E16655_01/server.121/e17750/ch4datetime.htm#NLSPG004.

Short rot13 function - Python

Here's a maketrans/translate solution

import string
rot13 = string.maketrans( 
    "ABCDEFGHIJKLMabcdefghijklmNOPQRSTUVWXYZnopqrstuvwxyz", 
    "NOPQRSTUVWXYZnopqrstuvwxyzABCDEFGHIJKLMabcdefghijklm")
string.translate("Hello World!", rot13)
# 'Uryyb Jbeyq!'

How to delete migration files in Rails 3

I usually:

  1. Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
  2. Delete the migration file manually.
  3. If there are pending migrations (i.e., the migration I removed was not the last one), I just perform a new rake db:migrate again.

If your application is already on production or staging, it's safer to just write another migration that destroys your table or columns.

Another great reference for migrations is: http://guides.rubyonrails.org/migrations.html

select a value where it doesn't exist in another table

You could use NOT IN:

SELECT A.* FROM A WHERE ID NOT IN(SELECT ID FROM B)

However, meanwhile i prefer NOT EXISTS:

SELECT A.* FROM A WHERE NOT EXISTS(SELECT 1 FROM B WHERE B.ID=A.ID)

There are other options as well, this article explains all advantages and disadvantages very well:

Should I use NOT IN, OUTER APPLY, LEFT OUTER JOIN, EXCEPT, or NOT EXISTS?

SET NOCOUNT ON usage

SET NOCOUNT ON even does allows to access to the affected rows like this:

SET NOCOUNT ON

DECLARE @test TABLE (ID int)

INSERT INTO @test
VALUES (1),(2),(3)

DECLARE @affectedRows int = -99  

DELETE top (1)
  FROM @test
SET @affectedRows = @@rowcount

SELECT @affectedRows as affectedRows

Results

affectedRows

1

Messages

Commands completed successfully.

Completion time: 2020-06-18T16:20:16.9686874+02:00

How to update Android Studio automatically?

Through Android Studio:

  1. Help
  2. Check for latest update
  3. Update

What is a reasonable length limit on person "Name" fields?

What you're really asking is a related, but substantially different question: how often do I want to truncate names in order to fit them in the database? The answer depends both on the frequency of different lengths of names as well as the maximum lengths chosen. This concern is balanced by the concerns about resources used by the database. Considering how little overhead difference there is between different max lengths for a varchar field I'd generally err on the side of never being forced to truncate a name and make the field as large as I dared.

Haskell: Converting Int to String

An example based on Chuck's answer:

myIntToStr :: Int -> String
myIntToStr x
    | x < 3     = show x ++ " is less than three"
    | otherwise = "normal"

Note that without the show the third line will not compile.

Function pointer as a member of a C struct

Maybe I am missing something here, but did you allocate any memory for that PString before you accessed it?

PString * initializeString() {
    PString *str;
    str = (PString *) malloc(sizeof(PString));
    str->length = &length;
    return str;
}

Using bind variables with dynamic SELECT INTO clause in PL/SQL

Put the select statement in a dynamic PL/SQL block.

CREATE OR REPLACE FUNCTION get_num_of_employees (p_loc VARCHAR2, p_job VARCHAR2) 
RETURN NUMBER
IS
  v_query_str VARCHAR2(1000);
  v_num_of_employees NUMBER;
BEGIN
  v_query_str := 'begin SELECT COUNT(*) INTO :into_bind FROM emp_' 
                 || p_loc
                 || ' WHERE job = :bind_job; end;';
  EXECUTE IMMEDIATE v_query_str
    USING out v_num_of_employees, p_job;
  RETURN v_num_of_employees;
END;
/

How to compile a 32-bit binary on a 64-bit linux machine with gcc/cmake

For C++, you could do:

export CXXFLAGS=-m32

This works with cmake.

jQuery DatePicker with today as maxDate

For those who dont want to use datepicker method

var alldatepicker=  $("[class$=hasDatepicker]");

alldatepicker.each(function(){

var value=$(this).val();

var today = new Date();

var dd = today.getDate();

var mm = today.getMonth()+1; //January is 0!

var yyyy = today.getFullYear();

if(dd<10) {

    dd='0'+dd

} 
if(mm<10) {

    mm='0'+mm

} 
today = mm+'/'+dd+'/'+yyyy;
if(value!=''){
if(value>today){
alert("Date cannot be greater than current date");
}
}
}); 

Java time-based map/cache with expiring keys

Sounds like ehcache is overkill for what you want, however note that it does not need external configuration files.

It is generally a good idea to move configuration into a declarative configuration files ( so you don't need to recompile when a new installation requires a different expiry time ), but it is not at all required, you can still configure it programmatically. http://www.ehcache.org/documentation/user-guide/configuration

Maven 3 Archetype for Project With Spring, Spring MVC, Hibernate, JPA

A great Spring MVC quickstart archetype is available on GitHub, courtesy of kolorobot. Good instructions are provided on how to install it to your local Maven repo and use it to create a new Spring MVC project. He’s even helpfully included the Tomcat 7 Maven plugin in the archetypical project so that the newly created Spring MVC can be run from the command line without having to manually deploy it to an application server.

Kolorobot’s example application includes the following:

  • No-xml Spring MVC 3.2 web application for Servlet 3.0 environment
  • Apache Tiles with configuration in place,
  • Bootstrap
  • JPA 2.0 (Hibernate/HSQLDB)
  • JUnit/Mockito
  • Spring Security 3.1

What is the difference between == and equals() in Java?

The difference between == and equals confused me for sometime until I decided to have a closer look at it. Many of them say that for comparing string you should use equals and not ==. Hope in this answer I will be able to say the difference.

The best way to answer this question will be by asking a few questions to yourself. so let's start:

What is the output for the below program:

String mango = "mango";
String mango2 = "mango";
System.out.println(mango != mango2);
System.out.println(mango == mango2);

if you say,

false
true

I will say you are right but why did you say that? and If you say the output is,

true
false

I will say you are wrong but I will still ask you, why you think that is right?

Ok, Let's try to answer this one:

What is the output for the below program:

String mango = "mango";
String mango3 = new String("mango");
System.out.println(mango != mango3);
System.out.println(mango == mango3);

Now If you say,

false
true

I will say you are wrong but why is it wrong now? the correct output for this program is

true
false

Please compare the above program and try to think about it.

Ok. Now this might help (please read this : print the address of object - not possible but still we can use it.)

String mango = "mango";
String mango2 = "mango";
String mango3 = new String("mango");
System.out.println(mango != mango2);
System.out.println(mango == mango2);
System.out.println(mango3 != mango2);
System.out.println(mango3 == mango2);
// mango2 = "mang";
System.out.println(mango+" "+ mango2);
System.out.println(mango != mango2);
System.out.println(mango == mango2);

System.out.println(System.identityHashCode(mango));
System.out.println(System.identityHashCode(mango2));
System.out.println(System.identityHashCode(mango3));

can you just try to think about the output of the last three lines in the code above: for me ideone printed this out (you can check the code here):

false
true
true
false
mango mango
false
true
17225372
17225372
5433634

Oh! Now you see the identityHashCode(mango) is equal to identityHashCode(mango2) But it is not equal to identityHashCode(mango3)

Even though all the string variables - mango, mango2 and mango3 - have the same value, which is "mango", identityHashCode() is still not the same for all.

Now try to uncomment this line // mango2 = "mang"; and run it again this time you will see all three identityHashCode() are different. Hmm that is a helpful hint

we know that if hashcode(x)=N and hashcode(y)=N => x is equal to y

I am not sure how java works internally but I assume this is what happened when I said:

mango = "mango";

java created a string "mango" which was pointed(referenced) by the variable mango something like this

mango ----> "mango"

Now in the next line when I said:

mango2 = "mango";

It actually reused the same string "mango" which looks something like this

mango ----> "mango" <---- mango2

Both mango and mango2 pointing to the same reference Now when I said

mango3 = new String("mango")

It actually created a completely new reference(string) for "mango". which looks something like this,

mango -----> "mango" <------ mango2

mango3 ------> "mango"

and that's why when I put out the values for mango == mango2, it put out true. and when I put out the value for mango3 == mango2, it put out false (even when the values were the same).

and when you uncommented the line // mango2 = "mang"; It actually created a string "mang" which turned our graph like this:

mango ---->"mango"
mango2 ----> "mang"
mango3 -----> "mango"

This is why the identityHashCode is not the same for all.

Hope this helps you guys. Actually, I wanted to generate a test case where == fails and equals() pass. Please feel free to comment and let me know If I am wrong.

How can I change my default database in SQL Server without using MS SQL Server Management Studio?

This may or may not exactly answer the question, but I ran into this issue (and question) when I had changed my account to have a new database I had created as my "default database". Then I deleted that database and wanted to test my creation script, from scratch. I logged off SSMS and was going to go back in, but was denied -- cannot log into default database was the error. D'oh!

What I did was, on the login dialog for SSMS, go to Options, Connection Properties, then type master on the "Connect to database" combobox. Click Connect. Got me in. From there you can run the command to:

ALTER LOGIN [DOMAIN\useracct] WITH DEFAULT_DATABASE=[master]
GO

Make a URL-encoded POST request using `http.NewRequest(...)`

URL-encoded payload must be provided on the body parameter of the http.NewRequest(method, urlStr string, body io.Reader) method, as a type that implements io.Reader interface.

Based on the sample code:

package main

import (
    "fmt"
    "net/http"
    "net/url"
    "strconv"
    "strings"
)

func main() {
    apiUrl := "https://api.com"
    resource := "/user/"
    data := url.Values{}
    data.Set("name", "foo")
    data.Set("surname", "bar")

    u, _ := url.ParseRequestURI(apiUrl)
    u.Path = resource
    urlStr := u.String() // "https://api.com/user/"

    client := &http.Client{}
    r, _ := http.NewRequest(http.MethodPost, urlStr, strings.NewReader(data.Encode())) // URL-encoded payload
    r.Header.Add("Authorization", "auth_token=\"XXXXXXX\"")
    r.Header.Add("Content-Type", "application/x-www-form-urlencoded")
    r.Header.Add("Content-Length", strconv.Itoa(len(data.Encode())))

    resp, _ := client.Do(r)
    fmt.Println(resp.Status)
}

resp.Status is 200 OK this way.

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

The best way to do this is avoid base *apply functions, which coerces the entire data frame to an array, possibly losing information.

If you wanted to apply a function as.numeric to every column, a simple way is using mutate_all from dplyr:

t %>% mutate_all(as.numeric)

Alternatively use colwise from plyr, which will "turn a function that operates on a vector into a function that operates column-wise on a data.frame."

t %>% (colwise(as.numeric))

In the special case of reading in a data table of character vectors and coercing columns into the correct data type, use type.convert or type_convert from readr.


Less interesting answer: we can apply on each column with a for-loop:

for (i in 1:nrow(t)) { t[, i] <- parse_guess(t[, i]) }

I don't know of a good way of doing assignment with *apply while preserving data frame structure.

GROUP BY having MAX date

There's no need to group in that subquery... a where clause would suffice:

SELECT * FROM tblpm n
WHERE date_updated=(SELECT MAX(date_updated)
    FROM tblpm WHERE control_number=n.control_number)

Also, do you have an index on the 'date_updated' column? That would certainly help.

Return string without trailing slash

The easies way i know of is this

function stipTrailingSlash(str){
   if(srt.charAt(str.length-1) == "/"){ str = str.substr(0, str.length - 1);}
   return str
}

This will then check for a / on the end and if its there remove it if its not will return your string as it was

Just one thing that i cant comment on yet @ThiefMaster wow you dont care about memory do you lol runnign a substr just for an if?

Fixed the calucation for zero-based index on the string.

How to change the default collation of a table?

It sets the default collation for the table; if you create a new column, that should be collated with latin_general_ci -- I think. Try specifying the collation for the individual column and see if that works. MySQL has some really bizarre behavior in regards to the way it handles this.

Adding a column to an existing table in a Rails migration

When I've done this, rather than fiddling the original migration, I create a new one with just the add column in the up section and a drop column in the down section.

You can change the original and rerun it if you migrate down between, but in this case I think that's made a migration that won't work properly.

As currently posted, you're adding the column and then creating the table.

If you change the order it might work. Or, as you're modifying an existing migration, just add it to the create table instead of doing a separate add column.

How can I run PowerShell with the .NET 4 runtime?

Here is the contents of the configuration file I used to support both .NET 2.0 and .NET 4 assemblies:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <!-- http://msdn.microsoft.com/en-us/library/w4atty68.aspx -->
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" />
    <supportedRuntime version="v2.0.50727" />
  </startup>
</configuration>

Also, here’s a simplified version of the PowerShell 1.0 compatible code I used to execute our scripts from the passed in command line arguments:

class Program {
  static void Main( string[] args ) {
    Console.WriteLine( ".NET " + Environment.Version );

    string script = "& " + string.Join( " ", args );
    Console.WriteLine( script );
    Console.WriteLine( );

    // Simple host that sends output to System.Console
    PSHost host = new ConsoleHost( this );
    Runspace runspace = RunspaceFactory.CreateRunspace( host );

    Pipeline pipeline = runspace.CreatePipeline( );
    pipeline.Commands.AddScript( script );

    try {
      runspace.Open( );
      IEnumerable<PSObject> output = pipeline.Invoke( );
      runspace.Close( );

      // ...
    }
    catch( RuntimeException ex ) {
      string psLine = ex.ErrorRecord.InvocationInfo.PositionMessage;
      Console.WriteLine( "error : {0}: {1}{2}", ex.GetType( ), ex.Message, psLine );
      ExitCode = -1;
    }
  }
}

In addition to the basic error handling shown above, we also inject a trap statement into the script to display additional diagnostic information (similar to Jeffrey Snover's Resolve-Error function).

How do I kill this tomcat process in Terminal?

this works very well (find tomcat processes and kill them forcibly)

ps -ef | grep tomcat | awk '{print $2}' | xargs kill -9

Adding a regression line on a ggplot

If you want to fit other type of models, like a dose-response curve using logistic models you would also need to create more data points with the function predict if you want to have a smoother regression line:

fit: your fit of a logistic regression curve

#Create a range of doses:
mm <- data.frame(DOSE = seq(0, max(data$DOSE), length.out = 100))
#Create a new data frame for ggplot using predict and your range of new 
#doses:
fit.ggplot=data.frame(y=predict(fit, newdata=mm),x=mm$DOSE)

ggplot(data=data,aes(x=log10(DOSE),y=log(viability)))+geom_point()+
geom_line(data=fit.ggplot,aes(x=log10(x),y=log(y)))

how to enable sqlite3 for php?

Edit: This answer is outdated, but can't be removed because it's accepted. Please see the solution from Stacey Richards for the correct answer.

 sudo apt-get install php5-cli php5-dev make
 sudo apt-get install libsqlite3-0 libsqlite3-dev
 sudo apt-get install php5-sqlite3
 sudo apt-get remove php5-sqlite3
 cd ~
 wget http://pecl.php.net/get/sqlite3-0.6.tgz
 tar -zxf sqlite3-0.6.tgz
 cd sqlite3-0.6/
 sudo phpize
 sudo ./configure
 sudo make
 sudo make install
 sudo apache2ctl restart

Ripped from the ubuntu form.

Python data structure sort list alphabetically

ListName.sort() will sort it alphabetically. You can add reverse=False/True in the brackets to reverse the order of items: ListName.sort(reverse=False)

Detect click outside React component

For those who need absolute positioning, a simple option I opted for is to add a wrapper component that is styled to cover the whole page with a transparent background. Then you can add an onClick on this element to close your inside component.

<div style={{
        position: 'fixed',
        top: '0', right: '0', bottom: '0', left: '0',
        zIndex: '1000',
      }} onClick={() => handleOutsideClick()} >
    <Content style={{position: 'absolute'}}/>
</div>

As it is right now if you add a click handler on content, the event will also be propagated to the upper div and therefore trigger the handlerOutsideClick. If this is not your desired behavior, simply stop the event progation on your handler.

<Content style={{position: 'absolute'}} onClick={e => {
                                          e.stopPropagation();
                                          desiredFunctionCall();
                                        }}/>

`

std::string to float or double

My Problem:

  1. Locale independent string to double (decimal separator always '.')
  2. Error detection if string conversion fails

My solution (uses the Windows function _wcstod_l):

// string to convert. Note: decimal seperator is ',' here
std::wstring str = L"1,101";

// Use this for error detection
wchar_t* stopString;

// Create a locale for "C". Thus a '.' is expected as decimal separator
double dbl = _wcstod_l(str.c_str(), &stopString, _create_locale(LC_ALL, "C")); 

if (wcslen(stopString) != 0)
{
    // ... error handling ... we'll run into this because of the separator
}

HTH ... took me pretty long to get to this solution. And I still have the feeling that I don't know enough about string localization and stuff...

Change collations of all columns of all tables in SQL Server

Using the cursor based variations above as a starting point, the script below will just output a set of UPDATE statements to set to DATABASE_DEFAULT, it won't actually do the UPDATES.

It supports schema, the full set of char and text types and retains the existing NULL / NOT NULL.

I plan to use the output to find to statements that fail in a lower environment and then manually adapt the resulting script to drop and recreate the constraints as needed.

DECLARE @collate nvarchar(100);
DECLARE @schema nvarchar(255);
DECLARE @table nvarchar(255);
DECLARE @column_name nvarchar(255);
DECLARE @column_id int;
DECLARE @data_type nvarchar(255);
DECLARE @max_length int;
DECLARE @max_length_str nvarchar(100);
DECLARE @is_nullable bit;
DECLARE @row_id int;
DECLARE @sql nvarchar(max);
DECLARE @sql_column nvarchar(max);

SET @collate = 'DATABASE_DEFAULT';

DECLARE local_table_cursor CURSOR FOR

SELECT (s.[name])schemaName, (o.[name])[tableName]
FROM sysobjects sy 
INNER JOIN sys.objects  o on o.name = sy.name
INNER JOIN sys.schemas s ON o.schema_id = s.schema_id
WHERE OBJECTPROPERTY(sy.id, N'IsUserTable') = 1
ORDER BY s.[name], o.[name]

OPEN local_table_cursor FETCH NEXT FROM local_table_cursor INTO @schema,@table

WHILE @@FETCH_STATUS = 0
BEGIN
    DECLARE local_change_cursor CURSOR FOR

    SELECT ROW_NUMBER() OVER (ORDER BY c.column_id) AS row_id
        , c.name column_name
        , t.Name data_type
        , col.CHARACTER_MAXIMUM_LENGTH
        , c.column_id
        , c.is_nullable
    FROM sys.columns c
    JOIN sys.types t ON c.system_type_id = t.system_type_id
    JOIN INFORMATION_SCHEMA.COLUMNS col on col.COLUMN_NAME = c.name and c.object_id = OBJECT_ID(col.TABLE_NAME)
    LEFT OUTER JOIN sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
    LEFT OUTER JOIN sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
    WHERE c.object_id = OBJECT_ID(@schema+'.'+@table) AND (t.Name LIKE '%char%' OR t.Name LIKE '%text%') 
    ORDER BY c.column_id

    OPEN local_change_cursor
    FETCH NEXT FROM local_change_cursor
    INTO @row_id, @column_name, @data_type, @max_length, @column_id, @is_nullable

    WHILE @@FETCH_STATUS = 0
    BEGIN

        SET @max_length_str = @max_length
        IF (@max_length = -1) SET @max_length_str = 'max'
        IF (@max_length > 4000) SET @max_length_str = '4000'

        SET @sql =
        CASE 
            WHEN @data_type like '%text%' 
            THEN 'ALTER TABLE [' + @schema+ '].['+ @table + '] ALTER COLUMN [' + @column_name + '] ' + @data_type + ' COLLATE ' + @collate + ' ' + CASE WHEN @is_nullable = 0 THEN 'NOT NULL' ELSE 'NULL' END
            ELSE 'ALTER TABLE [' + @schema+ '].['+ @table + '] ALTER COLUMN [' + @column_name + '] ' + @data_type + '(' + @max_length_str + ') COLLATE ' + @collate + ' ' + CASE WHEN @is_nullable = 0 THEN 'NOT NULL' ELSE 'NULL' END
        END
        PRINT @sql

        FETCH NEXT FROM local_change_cursor
        INTO @row_id, @column_name, @data_type, @max_length, @column_id, @is_nullable

    END

    CLOSE local_change_cursor
    DEALLOCATE local_change_cursor

    FETCH NEXT FROM local_table_cursor
    INTO @schema, @table
END

CLOSE local_table_cursor
DEALLOCATE local_table_cursor
GO

Why don’t my SVG images scale using the CSS "width" property?

You can also use the transform: scale("") option.

Android 6.0 Marshmallow. Cannot write to SD Card

I faced the same problem. There are two types of permissions in Android:

  • Dangerous (access to contacts, write to external storage...)
  • Normal

Normal permissions are automatically approved by Android while dangerous permissions need to be approved by Android users.

Here is the strategy to get dangerous permissions in Android 6.0

  1. Check if you have the permission granted
  2. If your app is already granted the permission, go ahead and perform normally.
  3. If your app doesn't have the permission yet, ask for user to approve
  4. Listen to user approval in onRequestPermissionsResult

Here is my case: I need to write to external storage.

First, I check if I have the permission:

...
private static final int REQUEST_WRITE_STORAGE = 112;
...
boolean hasPermission = (ContextCompat.checkSelfPermission(activity,
            Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED);
if (!hasPermission) {
    ActivityCompat.requestPermissions(parentActivity,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                REQUEST_WRITE_STORAGE);
}

Then check the user's approval:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode)
    {
        case REQUEST_WRITE_STORAGE: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                //reload my activity with permission granted or use the features what required the permission
            } else
            {
                Toast.makeText(parentActivity, "The app was not allowed to write to your storage. Hence, it cannot function properly. Please consider granting it this permission", Toast.LENGTH_LONG).show();
            }
        }
    }

}

You can read more about the new permission model here: https://developer.android.com/training/permissions/requesting.html

Activate tabpage of TabControl

Use SelectTab like this:

TabPage t = tabControl1.TabPages[2];
tabControl1.SelectTab(t); //go to tab

Use SelectedTab like this:

TabPage t = tabControl1.TabPages[2];
tabControl1.SelectedTab = t; //go to tab

Android Studio shortcuts like Eclipse

you can not remember all shortcuts :)
android studio(actually intellij) has a solution

quick command search : ctrl+shift+A

enter image description here

html form - make inputs appear on the same line

Try just putting a div around the first and last name inputs/labels like this:

<div class="name">
        <label for="First_Name">First Name:</label>
        <input name="first_name" id="First_Name" type="text" />

        <label for="Name">Last Name:</label>
        <input name="last_name" id="Last_Name" type="text" /> 
</div>

Look at the fiddle here: http://jsfiddle.net/XAkXg/

SQL Server : error converting data type varchar to numeric

I think the problem is not in sub-query but in WHERE clause of outer query. When you use

WHERE account_code between 503100 and 503105

SQL server will try to convert every value in your Account_code field to integer to test it in provided condition. Obviously it will fail to do so if there will be non-integer characters in some rows.

403 Access Denied on Tomcat 8 Manager App without prompting for user/password

I follwed the same tutorial but after some months I strangely got the error "403 Access Denied" while tryed to use Manager App. In this case I was using the ipaddress:8080 in the address bar and Tomcat Manager App didin't prompting for user/password. In case of localhost:8080 the error was "401", the dialogbox asking for username and password was displayed but the user not recognized.

I tried all the previous suggestions / solutions without lucky. The only way I found is been to repeat again the entire tutorial overwriting also the files. When finished, I found again the old deployed project into the webapps directory. Now Apache Tomcat/8.5.16 Manager App are working again. I do not know what happened I didn't understand also because I'm a newbie in Tomcat user

How to get the last five characters of a string using Substring() in C#?

If your input string could be less than five characters long then you should be aware that string.Substring will throw an ArgumentOutOfRangeException if the startIndex argument is negative.

To solve this potential problem you can use the following code:

string sub = input.Substring(Math.Max(0, input.Length - 5));

Or more explicitly:

public static string Right(string input, int length)
{
    if (length >= input.Length)
    {
        return input;
    }
    else
    {
        return input.Substring(input.Length - length);
    }
}

Accessing private member variables from prototype-defined functions

Can't you put the variables in a higher scope?

(function () {
    var privateVariable = true;

    var MyClass = function () {
        if (privateVariable) console.log('readable from private scope!');
    };

    MyClass.prototype.publicMethod = function () {
        if (privateVariable) console.log('readable from public scope!');
    };
}))();

How to split a string into a list?

str.split()

Return a list of the words in the string, using sep as the delimiter ... If sep is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace.

>>> line="a sentence with a few words"
>>> line.split()
['a', 'sentence', 'with', 'a', 'few', 'words']
>>> 

Show hide div using codebehind

Hiding on the Client Side with javascript

Using plain old javascript, you can easily hide the same element in this manner:

var myDivElem = document.getElementById("myDiv");
myDivElem.style.display = "none";

Then to show again:

myDivElem.style.display = "";

jQuery makes hiding elements a little simpler if you prefer to use jQuery:

var myDiv = $("#<%=myDiv.ClientID%>");
myDiv.hide();

... and to show:

myDiv.show();

Fastest way to check if a string is JSON in PHP?

Another simple way

function is_json($str)
{
    return is_array(json_decode($str,true));
}

Remove Blank option from Select Option with AngularJS

Also check whether you have any falsy value or not. Angularjs will insert an empty option if you do have falsy value. I struggled for 2 days just due to falsy value. I hope it will be helpful for someone.

I had options as [0, 1] and initially I was set the model to 0 due to that it was inserted empty option. Workaround for this was ["0" , "1"].

How do you clone a Git repository into a specific folder?

Make sure you remove the .git repository if you are trying to check thing out into the current directory.

rm -rf .git then git clone https://github.com/symfony/symfony-sandbox.git

Format date and Subtract days using Moment.js

startdate = moment().subtract(1, 'days').format('DD-MM-YYYY');

ReferenceError: describe is not defined NodeJs

if you are using vscode, want to debug your files

I used tdd before, it throw ReferenceError: describe is not defined

But, when I use bdd, it works!

waste half day to solve it....

    {
      "type": "node",
      "request": "launch",
      "name": "Mocha Tests",
      "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
      "args": [
        "-u",
        "bdd",// set to bdd, not tdd
        "--timeout",
        "999999",
        "--colors",
        "${workspaceFolder}/test/**/*.js"
      ],
      "internalConsoleOptions": "openOnSessionStart"
},

How to resolve cURL Error (7): couldn't connect to host?

Are you able to hit that URL by browser or by PHP script? The error shown is that you could not connect. So first confirm that the URL is accessible.

How to find whether a ResultSet is empty or not in Java?

if (rs == null || !rs.first()) {
    //empty
} else {
    //not empty
}

Note that after this method call, if the resultset is not empty, it is at the beginning.

Firebase FCM notifications click_action payload

Well this is clear from firebase docs that your onMessageReceived will not work when app is in background.

When your app is in background and click on your notification your default launcher will be launched. To launch your desired activity you need to specify click_action in your notification payload.

$noti = array
    (
    'icon' => 'new',
    'title' => 'title',
    'body' => 'new msg',
    'click_action' => 'your activity name comes here'
); 

And in your android.manifest file

Add the following code where you registered your activity

     <activity
                android:name="your activity name">
                <intent-filter>
                    <action android:name="your activity name" />
                   <category android:name="android.intent.category.DEFAULT"/>
               </intent-filter>
   </activity>

Is there a vr (vertical rule) in html?

How about:

writing-mode:tb-rl

Where top->bottom, right->left?

We will need vertical rule for this.

Testing socket connection in Python

It seems that you catch not the exception you wanna catch out there :)

if the s is a socket.socket() object, then the right way to call .connect would be:

import socket
s = socket.socket()
address = '127.0.0.1'
port = 80  # port number is a number, not string
try:
    s.connect((address, port)) 
    # originally, it was 
    # except Exception, e: 
    # but this syntax is not supported anymore. 
except Exception as e: 
    print("something's wrong with %s:%d. Exception is %s" % (address, port, e))
finally:
    s.close()

Always try to see what kind of exception is what you're catching in a try-except loop.

You can check what types of exceptions in a socket module represent what kind of errors (timeout, unable to resolve address, etc) and make separate except statement for each one of them - this way you'll be able to react differently for different kind of problems.

Find which rows have different values for a given column in Teradata SQL

This works for PL/SQL:

select count(*), id,address from table group by id,address having count(*)<2

How to check the value given is a positive or negative integer?

Starting from the base that the received value is a number and not a string, what about use Math.abs()? This JavaScript native function returns the absolute value of a number:

Math.abs(-1) // 1

So you can use it this way:

var a = -1;
if(a == Math.abs(a)){
    // false 
}

var b = 1;   
if(b == Math.abs(b)){
    // true
}