Programs & Examples On #Mips32

Advantage of switch over if-else statement

I would pick the if statement for the sake of clarity and convention, although I'm sure that some would disagree. After all, you are wanting to do something if some condition is true! Having a switch with one action seems a little... unneccesary.

Can I add and remove elements of enumeration at runtime in Java

No, enums are supposed to be a complete static enumeration.

At compile time, you might want to generate your enum .java file from another source file of some sort. You could even create a .class file like this.

In some cases you might want a set of standard values but allow extension. The usual way to do this is have an interface for the interface and an enum that implements that interface for the standard values. Of course, you lose the ability to switch when you only have a reference to the interface.

How to run cron once, daily at 10pm

Here is what I look at everytime I am writing a new crontab entry:

To start editing from terminal -type:

 zee$ crontab -e

what you will add to crontab file:

0 22 * * 0  some-user /opt/somescript/to/run.sh

What it means:

[ 
+ user => 'some-user',      
+ minute => ‘0’,             <<= on top of the hour.
+ hour => '22',              <<= at 10 PM. Military time.
+ monthday => '*',           <<= Every day of the month*
+ month => '*',              <<= Every month*
+ weekday => ‘0’,            <<= Everyday (0 thru 6) = sunday thru saturday
] 

Also, check what shell your machine is running and name the the file accordingly OR it wont execute.

Check the shell with either echo $SHELL or echo $0

It can be "Bourne shell (sh) , Bourne again shell (bash),Korn shell (ksh)..etc"

How to check if a process id (PID) exists

here i store the PID in a file called .pid (which is kind of like /run/...) and only execute the script if not already being executed.

#!/bin/bash
if [ -f .pid ]; then
  read pid < .pid
  echo $pid
  ps -p $pid > /dev/null
  r=$?
  if [ $r -eq 0 ]; then
    echo "$pid is currently running, not executing $0 twice, exiting now..."
    exit 1
  fi
fi

echo $$ > .pid

# do things here

rm .pid

note: there is a race condition as it does not check how that pid is called. if the system is rebooted and .pid exists but is used by a different application this might lead 'unforeseen consequences'.

.htaccess redirect www to non-www with SSL/HTTPS

This worked for me:

RewriteEngine On
RewriteCond %{HTTPS} on
RewriteCond %{HTTP_HOST} ^www\.(.*)
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

Custom Cell Row Height setting in storyboard is not responding

I think it is a bug.

Try adjust height not by Utility inspector but by mouse drag on the storyboard directly.

I solved this problem with this method.

How to add jQuery in JS file

just copy the code from the two files into your file at the top.

or use something like this http://code.google.com/p/minify/ to combine your files dynamically.

Josh

React-router: How to manually invoke Link?

In the version 5.x, you can use useHistory hook of react-router-dom:

// Sample extracted from https://reacttraining.com/react-router/core/api/Hooks/usehistory
import { useHistory } from "react-router-dom";

function HomeButton() {
  const history = useHistory();

  function handleClick() {
    history.push("/home");
  }

  return (
    <button type="button" onClick={handleClick}>
      Go home
    </button>
  );
}

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

Convert regular Python string to raw string

raw strings apply only to string literals. they exist so that you can more conveniently express strings that would be modified by escape sequence processing. This is most especially useful when writing out regular expressions, or other forms of code in string literals. if you want a unicode string without escape processing, just prefix it with ur, like ur'somestring'.

Get name of current script in Python

You can use __file__ to get the name of the current file. When used in the main module, this is the name of the script that was originally invoked.

If you want to omit the directory part (which might be present), you can use os.path.basename(__file__).

Is header('Content-Type:text/plain'); necessary at all?

Define "necessary".

It is necessary if you want the browser to know what the type of the file is. PHP automatically sets the Content-Type header to text/html if you don't override it so your browser is treating it as an HTML file that doesn't contain any HTML. If your output contained any HTML you'd see very different outcomes. If you were to send:

<b><i>test</i></b>

a Content-Type: text/html would output:

test

whereas Content-Type: text/plain would output:

<b><i>test</i></b>

TLDR Version: If you really are only outputing text then it doesn't really matter, but it IS wrong.

How to set a primary key in MongoDB?

Simple you can use

db.collectionName.createIndex({urfield:1},{unique:true});

How do you display a Toast from a background thread on Android?

Kotlin Code with runOnUiThread

runOnUiThread(
        object : Runnable {
            override fun run() {
                Toast.makeText(applicationContext, "Calling from runOnUiThread()", Toast.LENGTH_SHORT)  
            }
        }
)

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1

Can you try to change your json without data key like below?

[{"target_id":9503123,"target_type":"user"}]

Access is denied when attaching a database

In my case what solved the problem was the folowing:

USE [master]
GO
CREATE DATABASE [AdventureWorks2008R2] ON
( FILENAME = 'C:\Program Files\Microsfot SQL Server\MSSQL10_50.SQLEXPRESS\MSSQL\DATA\AdventureWors2008R2_Data.mdf')
FOR ATTACH_REBUILD_LOG

500 internal server error at GetResponse()

Finally I get rid of internal server error message with the following code. Not sure if there is another way to achieve it.


string uri = "Path.asmx";
string soap = "soap xml string";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Headers.Add("SOAPAction", "\"http://xxxxxx"");
request.ContentType = "text/xml;charset=\"utf-8\"";
request.Accept = "text/xml";
request.Method = "POST";

using (Stream stm = request.GetRequestStream())
{
    using (StreamWriter stmw = new StreamWriter(stm))
    {
        stmw.Write(soap);
    }
}

using (WebResponse webResponse = request.GetResponse())
{
}

How can I send JSON response in symfony2 controller

If your data is already serialized:

a) send a JSON response

public function someAction()
{
    $response = new Response();
    $response->setContent(file_get_contents('path/to/file'));
    $response->headers->set('Content-Type', 'application/json');
    return $response;
}

b) send a JSONP response (with callback)

public function someAction()
{
    $response = new Response();
    $response->setContent('/**/FUNCTION_CALLBACK_NAME(' . file_get_contents('path/to/file') . ');');
    $response->headers->set('Content-Type', 'text/javascript');
    return $response;
}

If your data needs be serialized:

c) send a JSON response

public function someAction()
{
    $response = new JsonResponse();
    $response->setData([some array]);
    return $response;
}

d) send a JSONP response (with callback)

public function someAction()
{
    $response = new JsonResponse();
    $response->setData([some array]);
    $response->setCallback('FUNCTION_CALLBACK_NAME');
    return $response;
}

e) use groups in Symfony 3.x.x

Create groups inside your Entities

<?php

namespace Mindlahus;

use Symfony\Component\Serializer\Annotation\Groups;

/**
 * Some Super Class Name
 *
 * @ORM    able("table_name")
 * @ORM\Entity(repositoryClass="SomeSuperClassNameRepository")
 * @UniqueEntity(
 *  fields={"foo", "boo"},
 *  ignoreNull=false
 * )
 */
class SomeSuperClassName
{
    /**
     * @Groups({"group1", "group2"})
     */
    public $foo;
    /**
     * @Groups({"group1"})
     */
    public $date;

    /**
     * @Groups({"group3"})
     */
    public function getBar() // is* methods are also supported
    {
        return $this->bar;
    }

    // ...
}

Normalize your Doctrine Object inside the logic of your application

<?php

use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactory;
// For annotations
use Doctrine\Common\Annotations\AnnotationReader;
use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
use Symfony\Component\Serializer\Serializer;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Encoder\JsonEncoder;

...

$repository = $this->getDoctrine()->getRepository('Mindlahus:SomeSuperClassName');
$SomeSuperObject = $repository->findOneById($id);

$classMetadataFactory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));
$encoder = new JsonEncoder();
$normalizer = new ObjectNormalizer($classMetadataFactory);
$callback = function ($dateTime) {
    return $dateTime instanceof \DateTime
        ? $dateTime->format('m-d-Y')
        : '';
};
$normalizer->setCallbacks(array('date' => $callback));
$serializer = new Serializer(array($normalizer), array($encoder));
$data = $serializer->normalize($SomeSuperObject, null, array('groups' => array('group1')));

$response = new Response();
$response->setContent($serializer->serialize($data, 'json'));
$response->headers->set('Content-Type', 'application/json');
return $response;

Getting the folder name from a path

var fullPath = @"C:\folder1\folder2\file.txt";
var lastDirectory = Path.GetDirectoryName(fullPath).Split('\\').LastOrDefault();

Command to collapse all sections of code?

The following key combinations are used to do things:

CTRL + M + M → Collapse / Expand current preset area (e.g. Method)

CTRL + M + H → Collapse / Hide (Expand) current selection

CTRL + M + O → Collapse all(Collapse declaration bodies)

CTRL + M + A → Collapse all

CTRL + M + X → Expand all

CTRL + M + L → Toggle all

There some options in the context menu under Outlining.

Creating a Shopping Cart using only HTML/JavaScript

For a project this size, you should stop writing pure JavaScript and turn to some of the libraries available. I'd recommend jQuery (http://jquery.com/), which allows you to select elements by css-selectors, which I recon should speed up your development quite a bit.

Example of your code then becomes;

function AddtoCart() {
  var len = $("#Items tr").length, $row, $inp1, $inp2, $cells;

  $row = $("#Items td:first").clone(true);
  $cells = $row.find("td");

  $cells.get(0).html( len );

  $inp1 = $cells.get(1).find("input:first");
  $inp1.attr("id", $inp1.attr("id") + len).val("");

  $inp2 = $cells.get(2).find("input:first");
  $inp2.attr("id", $inp2.attr("id") + len).val("");

  $("#Items").append($row);
    }

I can see that you might not understand that code yet, but take a look at jQuery, it's easy to learn and will make this development way faster.

I would use the libraries already created specifically for js shopping carts if I were you though.

To your problem; If i look at your jsFiddle, it doesn't even seem like you have defined a table with the id Items? Maybe that's why it doesn't work?

How to run eclipse in clean mode? what happens if we do so?

Two ways to run eclipse in clean mode.

1 ) In Eclipse.ini file

  • Open the eclipse.ini file located in the Eclipse installation directory.
  • Add -clean first line in the file.
  • Save the file.
  • Restart Eclipse.

enter image description here

2 ) From Command prompt (cmd/command)

  • Go to folder where Eclipse installed.
  • Take the path of Eclipse
  • C:..\eclipse\eclipse.exe -clean
  • press enter button

enter image description here

Control flow in T-SQL SP using IF..ELSE IF - are there other ways?

Nope IF is the way to go, what is the problem you have with using it?

BTW your example won't ever get to the third block of code as it and the second block are exactly alike.

Smooth scroll without the use of jQuery

Here's the code that worked for me.

`$('a[href*="#"]')

    .not('[href="#"]')
    .not('[href="#0"]')
    .click(function(event) {
     if (
       location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '')
       &&
       location.hostname == this.hostname
        ) {

  var target = $(this.hash);
  target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
  if (target.length) {

    event.preventDefault();
    $('html, body').animate({
      scrollTop: target.offset().top
    }, 1000, function() {

      var $target = $(target);
      $target.focus();
      if ($target.is(":focus")) { 
        return false;
      } else {
        $target.attr('tabindex','-1'); 
        $target.focus(); 
      };
    });
    }
   }
  });

`

Error: Could not find gradle wrapper within Android SDK. Might need to update your Android SDK - Android

Run:

cordova platform update [email protected]

And make sure that Android Studio and Android Studio environment variable refrence to same location.

I fix this by copying Android Studio from:

D:\Program Files\Android

to

C:\Program Files\Android

Why does fatal error "LNK1104: cannot open file 'C:\Program.obj'" occur when I compile a C++ project in Visual Studio?

I checked all my settings according to this list: http://msdn.microsoft.com/en-us/library/ts7eyw4s.aspx#feedback . It is helpful to me and for my situation, I find out that Link Dependency of projects' properties has double-quote, which should not be there.

Python function global variables?

Within a Python scope, any assignment to a variable not already declared within that scope creates a new local variable unless that variable is declared earlier in the function as referring to a globally scoped variable with the keyword global.

Let's look at a modified version of your pseudocode to see what happens:

# Here, we're creating a variable 'x', in the __main__ scope.
x = 'None!'

def func_A():
  # The below declaration lets the function know that we
  #  mean the global 'x' when we refer to that variable, not
  #  any local one

  global x
  x = 'A'
  return x

def func_B():
  # Here, we are somewhat mislead.  We're actually involving two different
  #  variables named 'x'.  One is local to func_B, the other is global.

  # By calling func_A(), we do two things: we're reassigning the value
  #  of the GLOBAL x as part of func_A, and then taking that same value
  #  since it's returned by func_A, and assigning it to a LOCAL variable
  #  named 'x'.     
  x = func_A() # look at this as: x_local = func_A()

  # Here, we're assigning the value of 'B' to the LOCAL x.
  x = 'B' # look at this as: x_local = 'B'

  return x # look at this as: return x_local

In fact, you could rewrite all of func_B with the variable named x_local and it would work identically.

The order matters only as far as the order in which your functions do operations that change the value of the global x. Thus in our example, order doesn't matter, since func_B calls func_A. In this example, order does matter:

def a():
  global foo
  foo = 'A'

def b():
  global foo
  foo = 'B'

b()
a()
print foo
# prints 'A' because a() was the last function to modify 'foo'.

Note that global is only required to modify global objects. You can still access them from within a function without declaring global. Thus, we have:

x = 5

def access_only():
  return x
  # This returns whatever the global value of 'x' is

def modify():
  global x
  x = 'modified'
  return x
  # This function makes the global 'x' equal to 'modified', and then returns that value

def create_locally():
  x = 'local!'
  return x
  # This function creates a new local variable named 'x', and sets it as 'local',
  #  and returns that.  The global 'x' is untouched.

Note the difference between create_locally and access_only -- access_only is accessing the global x despite not calling global, and even though create_locally doesn't use global either, it creates a local copy since it's assigning a value.

The confusion here is why you shouldn't use global variables.

how can I enable scrollbars on the WPF Datagrid?

If any of the parent containers RowDefinition Height set to "Auto" also stoppers for scrollbars

Alternatively you may set Height "*"

Which happened in my case.

PowerShell Connect to FTP server and get files

Invoke-WebRequest can download HTTP, HTTPS, and FTP links.

$source = 'ftp://Blah.com/somefile.txt'
$target = 'C:\Users\someuser\Desktop\BlahFiles\somefile.txt'
$password = Microsoft.PowerShell.Security\ConvertTo-SecureString -String 'mypassword' -AsPlainText -Force
$credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList myuserid, $password

# Download
Invoke-WebRequest -Uri $source -OutFile $target -Credential $credential -UseBasicParsing

Since the cmdlet uses IE parsing you may need the -UseBasicParsing switch. Test to make sure.

How can one develop iPhone apps in Java?

If you plan on integrating app functionality with a website, I'd highly recommend the GWT + PhoneGap model:

http://blog.daniel-kurka.de/2012/02/mgwt-and-phonegap-talk-at-webmontag-in.html http://turbomanage.wordpress.com/2010/09/24/gwt-phonegap-native-mobile-apps-quickly/

Here's my two cents from my own experience: We use the same Java POJOs for our Hibernate database, our REST API, our website, and our iPhone app. The workflow is simple and beautiful:

Database ---1---> REST API ---2---> iPhone App / Website

  • 1: Hibernate
  • 2: GSON Serialization and GWT JSON Deserialization

There is another benefit to this approach as well - any Java code that can be compiled with GWT and any JavaScript library become available for use in your iPhone app.

How to create a directive with a dynamic template in AngularJS?

One way is using a template function in your directive:

...
template: function(tElem, tAttrs){
    return '<div ng-include="' + tAttrs.template + '" />';
}
...

How can I bold the fonts of a specific row or cell in an Excel worksheet with C#?

I have done this in a project a long time ago. The code given below write a whole rows bold with specific column names and all of these columns are written in bold format.

private void WriteColumnHeaders(DataColumnCollection columnCollection, int row, int column)
    {
        // row represent particular row you want to bold its content.
        for (i = 0; i < columnCollection.Count; i++)
        {
            DataColumn col = columnCollection[i];
            xlWorkSheet.Cells[row, column + i + 1] = col.Caption;
            // Some Font Styles
            xlWorkSheet.Cells[row, column + i + 1].Style.Font.Bold = true;
            xlWorkSheet.Cells[row, column + i + 1].Interior.Color = Color.FromArgb(192, 192, 192);
            //xlWorkSheet.Columns[i + 1].ColumnWidth = xlWorkSheet.Columns[i+1].ColumnWidth + 10;
        }
    }

You must pass value of row 0 so that first row of your excel sheets have column headers with bold font size. Just change DataColumnCollection to your columns name and change col.Caption to specific column name.

Alternate

You may do this to cell of excel sheet you want bold.

xlWorkSheet.Cells[row, column].Style.Font.Bold = true;

Bootstrap Columns Not Working

Try this:

DEMO

<div class="container-fluid"> <!-- If Needed Left and Right Padding in 'md' and 'lg' screen means use container class -->
            <div class="row">
                <div class="col-xs-4 col-sm-4 col-md-4 col-lg-4">
                    <a href="#">About</a>
                </div>
                <div class="col-xs-4 col-sm-4 col-md-4 col-lg-4">
                    <img src="image.png" />
                </div>
                <div class="col-xs-4 col-sm-4 col-md-4 col-lg-4">
                    <a href="#myModal1" data-toggle="modal">SHARE</a>
                </div>
            </div>
        </div>

Clear the entire history stack and start a new activity on Android

Sometimes your android emulator might fails to connect eclipse DDMS tool and ask for adb to start manually. In that case you can start or stop the adb using the command prompt.

Dynamically change bootstrap progress bar value when checkboxes checked

Try this maybe :

Bootply : http://www.bootply.com/106527

Js :

$('input').on('click', function(){
  var valeur = 0;
  $('input:checked').each(function(){
       if ( $(this).attr('value') > valeur )
       {
           valeur =  $(this).attr('value');
       }
  });
  $('.progress-bar').css('width', valeur+'%').attr('aria-valuenow', valeur);    
});

HTML :

 <div class="progress progress-striped active">
        <div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">
        </div>
    </div>
<div class="row tasks">
        <div class="col-md-6">
          <p><span>Identify your campaign audience.</span>Who are we talking to here? Understand your buyer persona before launching into a campaign, so you can target them correctly.</p>
        </div>
        <div class="col-md-2">
          <label>2014-01-29</label>
        </div>
        <div class="col-md-2">
          <input name="progress" class="progress" type="checkbox" value="10">
        </div>
        <div class="col-md-2">
          <input name="done" class="done" type="checkbox" value="20">
        </div>
      </div><!-- tasks -->

<div class="row tasks">
        <div class="col-md-6">
          <p><span>Set your goals + benchmarks</span>Having SMART goals can help you be
sure that you’ll have tangible results to share with the world (or your
boss) at the end of your campaign.</p>
        </div>
        <div class="col-md-2">
          <label>2014-01-25</label>
        </div>
        <div class="col-md-2">
          <input name="progress" class="progress" type="checkbox" value="30">
        </div>
        <div class="col-md-2">
          <input name="done" class="done" type="checkbox" value="40">
        </div>
      </div><!-- tasks -->

Css

.tasks{
    background-color: #F6F8F8;
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
}
.tasks span{
    font-weight: bold;
}
.tasks input{
    display: block;
    margin: 0 auto;
    margin-top: 10px;
}
.tasks a{
    color: #000;
    text-decoration: none;
    border:none;
}
.tasks a:hover{
    border-bottom: dashed 1px #0088cc;
}
.tasks label{
    display: block;
    text-align: center;
}

_x000D_
_x000D_
$(function(){_x000D_
$('input').on('click', function(){_x000D_
  var valeur = 0;_x000D_
  $('input:checked').each(function(){_x000D_
       if ( $(this).attr('value') > valeur )_x000D_
       {_x000D_
           valeur =  $(this).attr('value');_x000D_
       }_x000D_
  });_x000D_
  $('.progress-bar').css('width', valeur+'%').attr('aria-valuenow', valeur);    _x000D_
});_x000D_
_x000D_
});
_x000D_
.tasks{_x000D_
 background-color: #F6F8F8;_x000D_
 padding: 10px;_x000D_
 border-radius: 5px;_x000D_
 margin-top: 10px;_x000D_
}_x000D_
.tasks span{_x000D_
 font-weight: bold;_x000D_
}_x000D_
.tasks input{_x000D_
 display: block;_x000D_
 margin: 0 auto;_x000D_
 margin-top: 10px;_x000D_
}_x000D_
.tasks a{_x000D_
 color: #000;_x000D_
 text-decoration: none;_x000D_
 border:none;_x000D_
}_x000D_
.tasks a:hover{_x000D_
 border-bottom: dashed 1px #0088cc;_x000D_
}_x000D_
.tasks label{_x000D_
 display: block;_x000D_
 text-align: center;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
 <div class="progress progress-striped active">_x000D_
        <div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">_x000D_
        </div>_x000D_
    </div>_x000D_
<div class="row tasks">_x000D_
        <div class="col-md-6">_x000D_
          <p><span>Identify your campaign audience.</span>Who are we talking to here? Understand your buyer persona before launching into a campaign, so you can target them correctly.</p>_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <label>2014-01-29</label>_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <input name="progress" class="progress" type="checkbox" value="10">_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <input name="done" class="done" type="checkbox" value="20">_x000D_
        </div>_x000D_
      </div><!-- tasks -->_x000D_
_x000D_
<div class="row tasks">_x000D_
        <div class="col-md-6">_x000D_
          <p><span>Set your goals + benchmarks</span>Having SMART goals can help you be_x000D_
sure that you’ll have tangible results to share with the world (or your_x000D_
boss) at the end of your campaign.</p>_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <label>2014-01-25</label>_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <input name="progress" class="progress" type="checkbox" value="30">_x000D_
        </div>_x000D_
        <div class="col-md-2">_x000D_
          <input name="done" class="done" type="checkbox" value="40">_x000D_
        </div>_x000D_
      </div><!-- tasks -->
_x000D_
_x000D_
_x000D_

HTML5 Form Input Pattern Currency Format

How about :

^\d+\.\d{2}$

This matches one or more digits, a dot and 2 digits after the dot.

To match also comma as thousands delimiter :

^\d+(?:,\d{3})*\.\d{2}$

How to manually send HTTP POST requests from Firefox or Chrome browser?

CURL is AWESOME to do what you want ! It's a simple but effective command line tool.

Rest implementation test commands :

curl -i -X GET http://rest-api.io/items
curl -i -X GET http://rest-api.io/items/5069b47aa892630aae059584
curl -i -X DELETE http://rest-api.io/items/5069b47aa892630aae059584
curl -i -X POST -H 'Content-Type: application/json' -d '{"name": "New item", "year": "2009"}' http://rest-api.io/items
curl -i -X PUT -H 'Content-Type: application/json' -d '{"name": "Updated item", "year": "2010"}' http://rest-api.io/items/5069b47aa892630aae059584

Difference between InvariantCulture and Ordinal string comparison

InvariantCulture

Uses a "standard" set of character orderings (a,b,c, ... etc.). This is in contrast to some specific locales, which may sort characters in different orders ('a-with-acute' may be before or after 'a', depending on the locale, and so on).

Ordinal

On the other hand, looks purely at the values of the raw byte(s) that represent the character.


There's a great sample at http://msdn.microsoft.com/en-us/library/e6883c06.aspx that shows the results of the various StringComparison values. All the way at the end, it shows (excerpted):

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

You can see that where InvariantCulture yields (U+0069, U+0049, U+00131), Ordinal yields (U+0049, U+0069, U+00131).

SQL Server Creating a temp table for this query

If you want to query the results from a temporary table inside the same query, you can use # temp tables, or @ table variables (I personally prefer @), for querying outside of the scope you would either want to use ## global temp tables or create a new table with the results.

DECLARE 
@ProjectID int = 3,
@Year int = 2010,
@MeterTypeID int = 1,
@StartDate datetime,
@EndDate datetime

SET @StartDate = '07/01/' + CAST(@Year as VARCHAR)
SET @EndDate = '06/30/' + CAST(@Year+1 as VARCHAR)

DECLARE @MyTempTable TABLE (SiteName varchar(50), BillingMonth varchar(10), Consumption float)

INSERT INTO @MyTempTable (SiteName, BillingMonth, Consumption)
SELECT  tblMEP_Sites.Name AS SiteName, convert(varchar(10),BillingMonth ,101) AS BillingMonth, SUM(Consumption) AS Consumption
FROM tblMEP_Projects

Will iOS launch my app into the background if it was force-quit by the user?

The answer is YES, but shouldn't use 'Background Fetch' or 'Remote notification'. PushKit is the answer you desire.

In summary, PushKit, the new framework in ios 8, is the new push notification mechanism which can silently launch your app into the background with no visual alert prompt even your app was killed by swiping out from app switcher, amazingly you even cannot see it from app switcher.

PushKit reference from Apple:

The PushKit framework provides the classes for your iOS apps to receive pushes from remote servers. Pushes can be of one of two types: standard and VoIP. Standard pushes can deliver notifications just as in previous versions of iOS. VoIP pushes provide additional functionality on top of the standard push that is needed to VoIP apps to perform on-demand processing of the push before displaying a notification to the user.

To deploy this new feature, please refer to this tutorial: https://zeropush.com/guide/guide-to-pushkit-and-voip - I've tested it on my device and it works as expected.

How to solve a pair of nonlinear equations using Python?

Try this one, I assure you that it will work perfectly.

    import scipy.optimize as opt
    from numpy import exp
    import timeit

    st1 = timeit.default_timer()

    def f(variables) :
        (x,y) = variables

        first_eq = x + y**2 -4
        second_eq = exp(x) + x*y - 3
        return [first_eq, second_eq]

    solution = opt.fsolve(f, (0.1,1) )
    print(solution)


    st2 = timeit.default_timer()
    print("RUN TIME : {0}".format(st2-st1))

->

[ 0.62034452  1.83838393]
RUN TIME : 0.0009331008900937708

FYI. as mentioned above, you can also use 'Broyden's approximation' by replacing 'fsolve' with 'broyden1'. It works. I did it.

I don't know exactly how Broyden's approximation works, but it took 0.02 s.

And I recommend you do not use Sympy's functions <- convenient indeed, but in terms of speed, it's quite slow. You will see.

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

The first part of your question is a duplicate of Why do I get a JsonReaderException with this code?, but the most relevant part from that (my) answer is this:

[A] JObject isn't the elementary base type of everything in JSON.net, but JToken is. So even though you could say,

object i = new int[0];

in C#, you can't say,

JObject i = JObject.Parse("[0, 0, 0]");

in JSON.net.

What you want is JArray.Parse, which will accept the array you're passing it (denoted by the opening [ in your API response). This is what the "StartArray" in the error message is telling you.

As for what happened when you used JArray, you're using arr instead of obj:

var rcvdData = JsonConvert.DeserializeObject<LocationData>(arr /* <-- Here */.ToString(), settings);

Swap that, and I believe it should work.

Although I'd be tempted to deserialize arr directly as an IEnumerable<LocationData>, which would save some code and effort of looping through the array. If you aren't going to use the parsed version separately, it's best to avoid it.

fatal: early EOF fatal: index-pack failed

I got this error when git ran out of memory.

Freeing up some memory (in this case: letting a compile job finish) and trying again worked for me.

How do I call a Django function on button click?

The following answer could be helpful for the first part of your question:

Django: How can I call a view function from template?

Convert LocalDateTime to LocalDateTime in UTC

Question?

Looking at the answers and the question, it seems the question has been modified significantly. So to answer the current question:

Convert LocalDateTime to LocalDateTime in UTC.

Timezone?

LocalDateTime does not store any information about the time-zone, it just basically holds the values of year, month, day, hour, minute, second, and smaller units. So an important question is: What is the timezone of the original LocalDateTime? It might as well be UTC already, therefore no conversion has to be made.

System Default Timezone

Considering that you asked the question anyway, you probably meant that the original time is in your system-default timezone and you want to convert it to UTC. Because usually a LocalDateTime object is created by using LocalDateTime.now() which returns the current time in the system-default timezone. In this case, the conversion would be the following:

LocalDateTime convertToUtc(LocalDateTime time) {
    return time.atZone(ZoneId.systemDefault()).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}

An example of the conversion process:

2019-02-25 11:39 // [time] original LocalDateTime without a timezone
2019-02-25 11:39 GMT+1 // [atZone] converted to ZonedDateTime (system timezone is Madrid)
2019-02-25 10:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2019-02-25 10:39 // [toLocalDateTime] losing the timezone information

Explicit Timezone

In any other case, when you explicitly specify the timezone of the time to convert, the conversion would be the following:

LocalDateTime convertToUtc(LocalDateTime time, ZoneId zone) {
    return time.atZone(zone).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}

An example of the conversion process:

2019-02-25 11:39 // [time] original LocalDateTime without a timezone
2019-02-25 11:39 GMT+2 // [atZone] converted to ZonedDateTime (zone is Europe/Tallinn)
2019-02-25 09:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2019-02-25 09:39 // [toLocalDateTime] losing the timezone information

The atZone() Method

The result of the atZone() method depends on the time passed as its argument, because it considers all the rules of the timezone, including Daylight Saving Time (DST). In the examples, the time was 25th February, in Europe this means winter time (no DST).

If we were to use a different date, let's say 25th August from last year, the result would be different, considering DST:

2018-08-25 11:39 // [time] original LocalDateTime without a timezone
2018-08-25 11:39 GMT+3 // [atZone] converted to ZonedDateTime (zone is Europe/Tallinn)
2018-08-25 08:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2018-08-25 08:39 // [toLocalDateTime] losing the timezone information

The GMT time does not change. Therefore the offsets in the other timezones are adjusted. In this example, the summer time of Estonia is GMT+3, and winter time GMT+2.

Also, if you specify a time within the transition of changing clocks back one hour. E.g. October 28th, 2018 03:30 for Estonia, this can mean two different times:

2018-10-28 03:30 GMT+3 // summer time [UTC 2018-10-28 00:30]
2018-10-28 04:00 GMT+3 // clocks are turned back 1 hour [UTC 2018-10-28 01:00]
2018-10-28 03:00 GMT+2 // same as above [UTC 2018-10-28 01:00]
2018-10-28 03:30 GMT+2 // winter time [UTC 2018-10-28 01:30]

Without specifying the offset manually (GMT+2 or GMT+3), the time 03:30 for the timezone Europe/Tallinn can mean two different UTC times, and two different offsets.

Summary

As you can see, the end result depends on the timezone of the time passed as an argument. Because the timezone cannot be extracted from the LocalDateTime object, you have to know yourself which timezone it is coming from in order to convert it to UTC.

How to Find And Replace Text In A File With C#

This is how I did it with a large (50 GB) file:

I tried 2 different ways: the first, reading the file into memory and using Regex Replace or String Replace. Then I appended the entire string to a temporary file.

The first method works well for a few Regex replacements, but Regex.Replace or String.Replace could cause out of memory error if you do many replaces in a large file.

The second is by reading the temp file line by line and manually building each line using StringBuilder and appending each processed line to the result file. This method was pretty fast.

static void ProcessLargeFile()
{
        if (File.Exists(outFileName)) File.Delete(outFileName);

        string text = File.ReadAllText(inputFileName, Encoding.UTF8);

        // EX 1 This opens entire file in memory and uses Replace and Regex Replace --> might cause out of memory error

        text = text.Replace("</text>", "");

        text = Regex.Replace(text, @"\<ref.*?\</ref\>", "");

        File.WriteAllText(outFileName, text);




        // EX 2 This reads file line by line 

        if (File.Exists(outFileName)) File.Delete(outFileName);

        using (var sw = new StreamWriter(outFileName))      
        using (var fs = File.OpenRead(inFileName))
        using (var sr = new StreamReader(fs, Encoding.UTF8)) //use UTF8 encoding or whatever encoding your file uses
        {
            string line, newLine;

            while ((line = sr.ReadLine()) != null)
            {
              //note: call your own replace function or use String.Replace here 
              newLine = Util.ReplaceDoubleBrackets(line);

              sw.WriteLine(newLine);
            }
        }
    }

    public static string ReplaceDoubleBrackets(string str)
    {
        //note: this replaces the first occurrence of a word delimited by [[ ]]

        //replace [[ with your own delimiter
        if (str.IndexOf("[[") < 0)
            return str;

        StringBuilder sb = new StringBuilder();

        //this part gets the string to replace, put this in a loop if more than one occurrence  per line.
        int posStart = str.IndexOf("[[");
        int posEnd = str.IndexOf("]]");
        int length = posEnd - posStart;


        // ... code to replace with newstr


        sb.Append(newstr);

        return sb.ToString();
    }

Split function equivalent in T-SQL?

/* *Object:  UserDefinedFunction [dbo].[Split]    Script Date: 10/04/2013 18:18:38* */
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [dbo].[Split]
(@List varchar(8000),@SplitOn Nvarchar(5))
RETURNS @RtnValue table
(Id int identity(1,1),Value nvarchar(100))
AS
BEGIN
    Set @List = Replace(@List,'''','')
    While (Charindex(@SplitOn,@List)>0)
    Begin

    Insert Into @RtnValue (value)
    Select
    Value = ltrim(rtrim(Substring(@List,1,Charindex(@SplitOn,@List)-1)))

    Set @List = Substring(@List,Charindex(@SplitOn,@List)+len(@SplitOn),len(@List))
    End

    Insert Into @RtnValue (Value)
    Select Value = ltrim(rtrim(@List))

    Return
END
go

Select *
From [Clv].[Split] ('1,2,3,3,3,3,',',')
GO

Can dplyr package be used for conditional mutating?

Since you ask for other better ways to handle the problem, here's another way using data.table:

require(data.table) ## 1.9.2+
setDT(df)
df[a %in% c(0,1,3,4) | c == 4, g := 3L]
df[a %in% c(2,5,7) | (a==1 & b==4), g := 2L]

Note the order of conditional statements is reversed to get g correctly. There's no copy of g made, even during the second assignment - it's replaced in-place.

On larger data this would have better performance than using nested if-else, as it can evaluate both 'yes' and 'no' cases, and nesting can get harder to read/maintain IMHO.


Here's a benchmark on relatively bigger data:

# R version 3.1.0
require(data.table) ## 1.9.2
require(dplyr)
DT <- setDT(lapply(1:6, function(x) sample(7, 1e7, TRUE)))
setnames(DT, letters[1:6])
# > dim(DT) 
# [1] 10000000        6
DF <- as.data.frame(DT)

DT_fun <- function(DT) {
    DT[(a %in% c(0,1,3,4) | c == 4), g := 3L]
    DT[a %in% c(2,5,7) | (a==1 & b==4), g := 2L]
}

DPLYR_fun <- function(DF) {
    mutate(DF, g = ifelse(a %in% c(2,5,7) | (a==1 & b==4), 2L, 
            ifelse(a %in% c(0,1,3,4) | c==4, 3L, NA_integer_)))
}

BASE_fun <- function(DF) { # R v3.1.0
    transform(DF, g = ifelse(a %in% c(2,5,7) | (a==1 & b==4), 2L, 
            ifelse(a %in% c(0,1,3,4) | c==4, 3L, NA_integer_)))
}

system.time(ans1 <- DT_fun(DT))
#   user  system elapsed 
#  2.659   0.420   3.107 

system.time(ans2 <- DPLYR_fun(DF))
#   user  system elapsed 
# 11.822   1.075  12.976 

system.time(ans3 <- BASE_fun(DF))
#   user  system elapsed 
# 11.676   1.530  13.319 

identical(as.data.frame(ans1), as.data.frame(ans2))
# [1] TRUE

identical(as.data.frame(ans1), as.data.frame(ans3))
# [1] TRUE

Not sure if this is an alternative you'd asked for, but I hope it helps.

How to get difference between two rows for a column field?

select t1.rowInt,t1.Value,t2.Value-t1.Value as diff
from (select * from myTable) as t1,
     (select * from myTable where rowInt!=1
      union all select top 1 rowInt=COUNT(*)+1,Value=0 from myTable) as t2
where t1.rowInt=t2.rowInt-1

Using JQuery to check if no radio button in a group has been checked

You could do something like this:

var radio_buttons = $("input[name='html_elements']");
if( radio_buttons.filter(':checked').length == 0){
  // None checked
} else {
  // If you need to use the result you can do so without
  // another (costly) jQuery selector call:
  var val = radio_buttons.val();
}

(change) vs (ngModelChange) in angular

1 - (change) is bound to the HTML onchange event. The documentation about HTML onchange says the following :

Execute a JavaScript when a user changes the selected option of a <select> element

Source : https://www.w3schools.com/jsref/event_onchange.asp

2 - As stated before, (ngModelChange) is bound to the model variable binded to your input.

So, my interpretation is :

  • (change) triggers when the user changes the input
  • (ngModelChange) triggers when the model changes, whether it's consecutive to a user action or not

SQL Query to fetch data from the last 30 days?

SELECT productid FROM product WHERE purchase_date > sysdate-30

How to use a DataAdapter with stored procedure and parameter

I got it!...hehe

protected DataTable RetrieveEmployeeSubInfo(string employeeNo)
        {
            SqlCommand cmd = new SqlCommand();
            SqlDataAdapter da = new SqlDataAdapter();
            DataTable dt = new DataTable();
            try
            {
                cmd = new SqlCommand("RETRIEVE_EMPLOYEE", pl.ConnOpen());
                cmd.Parameters.Add(new SqlParameter("@EMPLOYEENO", employeeNo));
                cmd.CommandType = CommandType.StoredProcedure;
                da.SelectCommand = cmd;
                da.Fill(dt);
                dataGridView1.DataSource = dt;
            }
            catch (Exception x)
            {
                MessageBox.Show(x.GetBaseException().ToString(), "Error",
                        MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                cmd.Dispose();
                pl.MySQLConn.Close();
            }
            return dt;
        }

How to return HTTP 500 from ASP.NET Core RC2 Web Api?

A better way to handle this as of now (1.1) is to do this in Startup.cs's Configure():

app.UseExceptionHandler("/Error");

This will execute the route for /Error. This will save you from adding try-catch blocks to every action you write.

Of course, you'll need to add an ErrorController similar to this:

[Route("[controller]")]
public class ErrorController : Controller
{
    [Route("")]
    [AllowAnonymous]
    public IActionResult Get()
    {
        return StatusCode(StatusCodes.Status500InternalServerError);
    }
}

More information here.


In case you want to get the actual exception data, you may add this to the above Get() right before the return statement.

// Get the details of the exception that occurred
var exceptionFeature = HttpContext.Features.Get<IExceptionHandlerPathFeature>();

if (exceptionFeature != null)
{
    // Get which route the exception occurred at
    string routeWhereExceptionOccurred = exceptionFeature.Path;

    // Get the exception that occurred
    Exception exceptionThatOccurred = exceptionFeature.Error;

    // TODO: Do something with the exception
    // Log it with Serilog?
    // Send an e-mail, text, fax, or carrier pidgeon?  Maybe all of the above?
    // Whatever you do, be careful to catch any exceptions, otherwise you'll end up with a blank page and throwing a 500
}

Above snippet taken from Scott Sauber's blog.

Setting up a git remote origin

Using SSH

git remote add origin ssh://login@IP/path/to/repository

Using HTTP

git remote add origin http://IP/path/to/repository

However having a simple git pull as a deployment process is usually a bad idea and should be avoided in favor of a real deployment script.

javascript setTimeout() not working

Two things.

  1. Remove the parenthesis in setTimeout(startTimer(),startInterval);. Keeping the parentheses invokes the function immediately.

  2. Your startTimer function will overwrite the page content with your use of document.write (without the above fix), and wipes out the script and HTML in the process.

Select multiple columns from a table, but group by one

    WITH CTE_SUM AS (
      SELECT ProductID, Sum(OrderQuantity) AS TotalOrderQuantity 
      FROM OrderDetails GROUP BY ProductID
    )
    SELECT DISTINCT OrderDetails.ProductID, OrderDetails.ProductName, OrderDetails.OrderQuantity,CTE_SUM.TotalOrderQuantity 
    FROM 
    OrderDetails INNER JOIN CTE_SUM 
    ON OrderDetails.ProductID = CTE_SUM.ProductID

Please check if this works.

Receive JSON POST with PHP

Quite late.
It seems, (OP) had already tried all the answers given to him.
Still if you (OP) were not receiving what had been passed to the ".PHP" file, error could be, incorrect URL.
Check whether you are calling the correct ".PHP" file.
(spelling mistake or capital letter in URL)
and most important
Check whether your URL has "s" (secure) after "http".
Example:

"http://yourdomain.com/read_result.php"

should be

"https://yourdomain.com/read_result.php"

or either way.
add or remove the "s" to match your URL.

<meta charset="utf-8"> vs <meta http-equiv="Content-Type">

In HTML5, they are equivalent. Use the shorter one, it is easier to remember and type. Browser support is fine since it was designed for backwards compatibility.

Sorting arrays in javascript by object key value

This worked for me

var files=data.Contents;
          files = files.sort(function(a,b){
        return a.LastModified - b. LastModified;
      });

OR use Lodash to sort the array

files = _.orderBy(files,'LastModified','asc');

Percentage calculation

Mathematically, to get percentage from two numbers:

percentage = (yourNumber / totalNumber) * 100;

And also, to calculate from a percentage :

number = (percentage / 100) * totalNumber;

Why is there no multiple inheritance in Java, but implementing multiple interfaces is allowed?

One of my college instructors explained it to me this way:

Suppose I have one class, which is a Toaster, and another class, which is NuclearBomb. They both might have a "darkness" setting. They both have an on() method. (One has an off(), the other doesn't.) If I want to create a class that's a subclass of both of these...as you can see, this is a problem that could really blow up in my face here.

So one of the main issues is that if you have two parent classes, they might have different implementations of the same feature — or possibly two different features with the same name, as in my instructor's example. Then you have to deal with deciding which one your subclass is going to use. There are ways of handling this, certainly — C++ does so — but the designers of Java felt that this would make things too complicated.

With an interface, though, you're describing something the class is capable of doing, rather than borrowing another class's method of doing something. Multiple interfaces are much less likely to cause tricky conflicts that need to be resolved than are multiple parent classes.

Python progression path - From apprentice to guru

I learned python first by myself over a summer just by doing the tutorial on the python site (sadly, I don't seem to be able to find that anymore, so I can't post a link).

Later, python was taught to me in one of my first year courses at university. In the summer that followed, I practiced with PythonChallenge and with problems from Google Code Jam. Solving these problems help from an algorithmic perspective as well as from the perspective of learning what Python can do as well as how to manipulate it to get the fullest out of python.

For similar reasons, I have heard that code golf works as well, but i have never tried it for myself.

Error: getaddrinfo ENOTFOUND in nodejs for get call

When I tried to install a new ionic app, I got the same error as follows, I tried many sources and found the mistake made in User Environment and System Environment unnecessarily included the PROXY value. I removed the ```user variables http://host:port PROXY

system Variables http_proxy http://username:password@host:port ```` and now it is working fine without trouble.

[ERROR] Network connectivity error occurred, are you offline?

        If you are behind a firewall and need to configure proxy settings, see: https://ion.link/cli-proxy-docs

        Error: getaddrinfo ENOTFOUND host host:80

How to run Python script on terminal?

You first must install python. Mac comes with python 2.7 installed to install Python 3 you can follow this tutorial: http://docs.python-guide.org/en/latest/starting/install3/osx/.

To run the program you can then copy and paste in this code:

python /Users/luca/Documents/python/gameover.py

Or you can go to the directory of the file with cd followed by the folder. When you are in the folder you can then python YourFile.py.

Capturing image from webcam in java?

I have used JMF on a videoconference application and it worked well on two laptops: one with integrated webcam and another with an old USB webcam. It requires JMF being installed and configured before-hand, but once you're done you can access the hardware via Java code fairly easily.

Setting network adapter metric priority in Windows 7

Windows has two different settings in which priority is established. There is the metric value which you have already set in the adapter settings, and then there is the connection priority in the network connections settings.

To change the priority of the connections:

  • Open your Adapter Settings (Control Panel\Network and Internet\Network Connections)
  • Click Alt to pull up the menu bar
  • Select Advanced -> Advanced Settings
  • Change the order of the connections so that the connection you want to have priority is top on the list

jquery - is not a function error

change

});


$(document).ready(function () {
    $('.smallTabsHeader a').pluginbutton();
});

to

})(jQuery); //<-- ADD THIS


$(document).ready(function () {
    $('.smallTabsHeader a').pluginbutton();
});

This is needed because, you need to call the anonymous function that you created with

(function($){

and notice that it expects an argument that it will use internally as $, so you need to pass a reference to the jQuery object.

Additionally, you will need to change all the this. to $(this)., except the first one, in which you do return this.each

In the first one (where you do not need the $()) it is because in the plugin body, this holds a reference to the jQuery object matching your selector, but anywhere deeper than that, this refers to the specific DOM element, so you need to wrap it in $().

Full code at http://jsfiddle.net/gaby/NXESk/

How to simplify a null-safe compareTo() implementation?

In case anyone using Spring, there is a class org.springframework.util.comparator.NullSafeComparator that does this for you as well. Just decorate your own comparable with it like this

new NullSafeComparator<YourObject>(new YourComparable(), true)

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/util/comparator/NullSafeComparator.html

Angular 2 router no base href set

Check your index.html. If you have accidentally removed the following part, include it and it will be fine

<base href="/">

<meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/x-icon" href="favicon.ico">

How can I get a first element from a sorted list?

playersList.get(0)

Java has limited operator polymorphism. So you use the get() method on List objects, not the array index operator ([])

How To Change DataType of a DataColumn in a DataTable?

if you want to change only a column.for example from string to int32 you can use Expression property:

DataColumn col = new DataColumn("col_int" , typeof(int));
table.Columns.Add(col);
col.Expression = "table_exist_col_string"; // digit string convert to int  

Check orientation on Android phone

A fully way to specify the current orientation of the phone:

public String getRotation(Context context) {
    final int rotation = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getOrientation();
    switch (rotation) {
        case Surface.ROTATION_0:
            return "portrait";
        case Surface.ROTATION_90:
            return "landscape";
        case Surface.ROTATION_180:
            return "reverse portrait";
        default:
            return "reverse landscape";
    }
}

Push method in React Hooks (useState)?

The same way you do it with "normal" state in React class components.

example:

function App() {
  const [state, setState] = useState([]);

  return (
    <div>
      <p>You clicked {state.join(" and ")}</p>
      //destructuring
      <button onClick={() => setState([...state, "again"])}>Click me</button>
      //old way
      <button onClick={() => setState(state.concat("again"))}>Click me</button>
    </div>
  );
}

How do I use SELECT GROUP BY in DataTable.Select(Expression)?

dt.AsEnumerable()
    .GroupBy(r => new { Col1 = r["Col1"], Col2 = r["Col2"] })
    .Select(g =>
    {
        var row = dt.NewRow();

        row["PK"] = g.Min(r => r.Field<int>("PK"));
        row["Col1"] = g.Key.Col1;
        row["Col2"] = g.Key.Col2;

        return row;

    })
    .CopyToDataTable();

Can a CSV file have a comment?

I think the best way to add comments to a CSV file would be to add a "Comments" field or record right into the data.

Most CSV-parsing applications that I've used implement both field-mapping and record-choosing. So, to comment on the properties of a field, add a record just for field descriptions. To comment on a record, add a field at the end of it (well, all records, really) just for comments.

These are the only two reasons I can think of to comment a CSV file. But the only problem I can foresee would be programs that refuse to accept the file at all if any single record doesn't pass some validation rules. In that case, you'd have trouble writing a string-type field description record for any numeric fields.

I am by no means an expert, though, so feel free to point out any mistakes in my theory.

Compare two dates in Java

Here's what you can do for say yyyy-mm-dd comparison:

GregorianCalendar gc= new GregorianCalendar();
gc.setTimeInMillis(System.currentTimeMillis());
gc.roll(GregorianCalendar.DAY_OF_MONTH, true);

Date d1 = new Date();
Date d2 = gc.getTime();

SimpleDateFormat sf= new SimpleDateFormat("yyyy-MM-dd");

if(sf.format(d2).hashCode() < sf.format(d1).hashCode())
{
    System.out.println("date 2 is less than date 1");
}
else
{
    System.out.println("date 2 is equal or greater than date 1");
}

slashes in url variables

You need to escape the slashes as %2F.

React Hook Warnings for async function in useEffect: useEffect function must return a cleanup function or nothing

When you use an async function like

async () => {
    try {
        const response = await fetch(`https://www.reddit.com/r/${subreddit}.json`);
        const json = await response.json();
        setPosts(json.data.children.map(it => it.data));
    } catch (e) {
        console.error(e);
    }
}

it returns a promise and useEffect doesn't expect the callback function to return Promise, rather it expects that nothing is returned or a function is returned.

As a workaround for the warning you can use a self invoking async function.

useEffect(() => {
    (async function() {
        try {
            const response = await fetch(
                `https://www.reddit.com/r/${subreddit}.json`
            );
            const json = await response.json();
            setPosts(json.data.children.map(it => it.data));
        } catch (e) {
            console.error(e);
        }
    })();
}, []);

or to make it more cleaner you could define a function and then call it

useEffect(() => {
    async function fetchData() {
        try {
            const response = await fetch(
                `https://www.reddit.com/r/${subreddit}.json`
            );
            const json = await response.json();
            setPosts(json.data.children.map(it => it.data));
        } catch (e) {
            console.error(e);
        }
    };
    fetchData();
}, []);

the second solution will make it easier to read and will help you write code to cancel previous requests if a new one is fired or save the latest request response in state

Working codesandbox

Git Bash won't run my python files?

That command did not work for me, I used:

$ export PATH="$PATH:/c/Python27"

Then to make sure that git remembers the python path every time you open git type the following.

echo 'export PATH="$PATH:/c/Python27"' > .profile

Creating a blocking Queue<T> in .NET?

Use .net 4 BlockingCollection, to enqueue use Add(), to dequeue use Take(). It internally uses non-blocking ConcurrentQueue. More info here Fast and Best Producer/consumer queue technique BlockingCollection vs concurrent Queue

Android update activity UI from service

I would recommend checking out Otto, an EventBus tailored specifically to Android. Your Activity/UI can listen to events posted on the Bus from the Service, and decouple itself from the backend.

How to create a numpy array of arbitrary length strings?

You could use the object data type:

>>> import numpy
>>> s = numpy.array(['a', 'b', 'dude'], dtype='object')
>>> s[0] += 'bcdef'
>>> s
array([abcdef, b, dude], dtype=object)

Get GPS location from the web browser

There is the GeoLocation API, but browser support is rather thin on the ground at present. Most sites that care about such things use a GeoIP database (with the usual provisos about the inaccuracy of such a system). You could also look at third party services requiring user cooperation such as FireEagle.

How to use IntelliJ IDEA to find all unused code?

Just use Analyze | Inspect Code with appropriate inspection enabled (Unused declaration under Declaration redundancy group).

Using IntelliJ 11 CE you can now "Analyze | Run Inspection by Name ... | Unused declaration"

Concatenate two string literals

Your second example does not work because there is no operator + for two string literals. Note that a string literal is not of type string, but instead is of type const char *. Your second example will work if you revise it like this:

const string message = string("Hello") + ",world" + exclam;

SQL Server SELECT into existing table

There are two different ways to implement inserting data from one table to another table.

For Existing Table - INSERT INTO SELECT

This method is used when the table is already created in the database earlier and the data is to be inserted into this table from another table. If columns listed in insert clause and select clause are same, they are not required to list them. It is good practice to always list them for readability and scalability purpose.

----Create testable
CREATE TABLE TestTable (FirstName VARCHAR(100), LastName VARCHAR(100))
----INSERT INTO TestTable using SELECT
INSERT INTO TestTable (FirstName, LastName)
SELECT FirstName, LastName
FROM Person.Contact
WHERE EmailPromotion = 2
----Verify that Data in TestTable
SELECT FirstName, LastName
FROM TestTable
----Clean Up Database
DROP TABLE TestTable

For Non-Existing Table - SELECT INTO

This method is used when the table is not created earlier and needs to be created when data from one table is to be inserted into the newly created table from another table. The new table is created with the same data types as selected columns.

----Create a new table and insert into table using SELECT INSERT
SELECT FirstName, LastName
INTO TestTable
FROM Person.Contact
WHERE EmailPromotion = 2
----Verify that Data in TestTable
SELECT FirstName, LastName
FROM TestTable
----Clean Up Database
DROP TABLE TestTable

Ref 1 2

How to get root access on Android emulator?

I believe that the easiest way is to create an alias for the command sh, e.g.

adb shell
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
cd /system/bin
cat sh > su && chmod 4775 su

Tested on Android Emulator 3.0 and higher.

Code signing is required for product type 'Application' in SDK 'iOS5.1'

The other issue here lies under Code Signing Identity under the Build Settings. Be sure that it contains the Code Signing Identity: "iOS Developer" as opposed to "Don't Code Sign." This will allow you to deploy it to your iOS device. Especially, if you have downloaded a GitHub example or something to this effect.

jackson deserialization json to java-objects

You have to change the line

product userFromJSON = mapper.readValue(userDataJSON, product.class);

to

product[] userFromJSON = mapper.readValue(userDataJSON, product[].class);

since you are deserializing an array (btw: you should start your class names with upper case letters as mentioned earlier). Additionally you have to create setter methods for your fields or mark them as public in order to make this work.

Edit: You can also go with Steven Schlansker's suggestion and use

List<product> userFromJSON =
        mapper.readValue(userDataJSON, new TypeReference<List<product>>() {});

instead if you want to avoid arrays.

Rails: Address already in use - bind(2) (Errno::EADDRINUSE)

you can also try this trick:

ps aux | grep puma

sample output:

myname           77921   0.0  0.0  2433828   1972 s000  R+   11:17AM   0:00.00 grep puma
myname           67661   0.0  2.3  2680504 191204 s002  S+   11:00AM   0:18.38 puma 3.11.2 (tcp://localhost:3000) [my_proj]

then:

kill -9 67661

CMD: How do I recursively remove the "Hidden"-Attribute of files and directories

To make a batch file for its current directory and sub directories:

cd %~dp0
attrib -h -r -s /s /d /l *.*

Best way to center a <div> on a page vertically and horizontally?

Though I'm too late, but this is very easy and simple. Page center is always left 50%, and top 50%. So minus the div width and height 50% and set left margin and right margin. Hope it work's for everywhere -

_x000D_
_x000D_
body{_x000D_
  background: #EEE;_x000D_
}_x000D_
.center-div{_x000D_
  position: absolute;_x000D_
  width: 200px;_x000D_
  height: 60px;_x000D_
  left: 50%;  _x000D_
  margin-left: -100px;_x000D_
  top: 50%;_x000D_
  margin-top: -30px;_x000D_
  background: #CCC;_x000D_
  color: #000;_x000D_
  text-align: center;_x000D_
}
_x000D_
<div class="center-div">_x000D_
  <h3>This is center div</h3>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Double decimal formatting in Java

An alternative method is use the setMinimumFractionDigits method from the NumberFormat class.

Here you basically specify how many numbers you want to appear after the decimal point.

So an input of 4.0 would produce 4.00, assuming your specified amount was 2.

But, if your Double input contains more than the amount specified, it will take the minimum amount specified, then add one more digit rounded up/down

For example, 4.15465454 with a minimum amount of 2 specified will produce 4.155

NumberFormat nf = NumberFormat.getInstance();
nf.setMinimumFractionDigits(2);
Double myVal = 4.15465454;
System.out.println(nf.format(myVal));

Try it online

In Laravel, the best way to pass different types of flash messages in the session

For my application i made a helper function:

function message( $message , $status = 'success', $redirectPath = null )
{
     $redirectPath = $redirectPath == null ? back() : redirect( $redirectPath );

     return $redirectPath->with([
         'message'   =>  $message,
         'status'    =>  $status,
    ]);
}

message layout, main.layouts.message:

@if($status)
   <div class="center-block affix alert alert-{{$status}}">
     <i class="fa fa-{{ $status == 'success' ? 'check' : $status}}"></i>
     <span>
        {{ $message }}
     </span>
   </div>
@endif

and import every where to show message:

@include('main.layouts.message', [
    'status'    =>  session('status'),
    'message'   =>  session('message'),
])

INSERT INTO @TABLE EXEC @query with SQL Server 2000

DECLARE @q nvarchar(4000)
SET @q = 'DECLARE @tmp TABLE (code VARCHAR(50), mount MONEY)
INSERT INTO @tmp
  (
    code,
    mount
  )
SELECT coa_code,
       amount
FROM   T_Ledger_detail

SELECT *
FROM   @tmp'

EXEC sp_executesql @q

If you want in dynamic query

How to apply font anti-alias effects in CSS?

Works the best. If you want to use it sitewide, without having to add this syntax to every class or ID, add the following CSS to your css body:

body { 
    -webkit-font-smoothing: antialiased;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.004);
    background: url('./images/background.png');
    text-align: left;
    margin: auto;

}

How can I make visible an invisible control with jquery? (hide and show not work)

Here's some code I use to deal with this.

First we show the element, which will typically set the display type to "block" via .show() function, and then set the CSS rule to "visible":

jQuery( '.element' ).show().css( 'visibility', 'visible' );

Or, assuming that the class that is hiding the element is called hidden, such as in Twitter Bootstrap, toggleClass() can be useful:

jQuery( '.element' ).toggleClass( 'hidden' );

Lastly, if you want to chain functions, perhaps with fancy with a fading effect, you can do it like so:

jQuery( '.element' ).css( 'visibility', 'visible' ).fadeIn( 5000 );

How to input a path with a white space?

SOME_PATH=/mnt/someProject/some\ path

should work

The "backspace" escape character '\b': unexpected behavior?

..........
^ <= pointer to "print head"
            /* part1 */
            printf("hello worl");
hello worl
          ^ <= pointer to "print head"
            /* part2 */
            printf("\b");
hello worl
         ^ <= pointer to "print head"
            /* part3 */
            printf("\b");
hello worl
        ^ <= pointer to "print head"
            /* part4 */
            printf("d\n");
hello wodl

^ <= pointer to "print head" on the next line

How to preview an image before and after upload?

meVeekay's answer was good and am just making it more improvised by doing 2 things.

  1. Check whether browser supports HTML5 FileReader() or not.

  2. Allow only image file to be upload by checking its extension.

HTML :

<div id="wrapper">
    <input id="fileUpload" type="file" />
    <br />
    <div id="image-holder"></div>
</div> 

jQuery :

$("#fileUpload").on('change', function () {

    var imgPath = $(this)[0].value;
    var extn = imgPath.substring(imgPath.lastIndexOf('.') + 1).toLowerCase();

    if (extn == "gif" || extn == "png" || extn == "jpg" || extn == "jpeg") {
        if (typeof (FileReader) != "undefined") {

            var image_holder = $("#image-holder");
            image_holder.empty();

            var reader = new FileReader();
            reader.onload = function (e) {
                $("<img />", {
                    "src": e.target.result,
                        "class": "thumb-image"
                }).appendTo(image_holder);

            }
            image_holder.show();
            reader.readAsDataURL($(this)[0].files[0]);
        } else {
            alert("This browser does not support FileReader.");
        }
    } else {
        alert("Pls select only images");
    }
});

For detail understanding of FileReader()

Check this Article : Using FileReader() preview image before uploading.

How to validate an OAuth 2.0 access token for a resource server?

Update Nov. 2015: As per Hans Z. below - this is now indeed defined as part of RFC 7662.

Original Answer: The OAuth 2.0 spec (RFC 6749) doesn't clearly define the interaction between a Resource Server (RS) and Authorization Server (AS) for access token (AT) validation. It really depends on the AS's token format/strategy - some tokens are self-contained (like JSON Web Tokens) while others may be similar to a session cookie in that they just reference information held server side back at the AS.

There has been some discussion in the OAuth Working Group about creating a standard way for an RS to communicate with the AS for AT validation. My company (Ping Identity) has come up with one such approach for our commercial OAuth AS (PingFederate): https://support.pingidentity.com/s/document-item?bundleId=pingfederate-93&topicId=lzn1564003025072.html#lzn1564003025072__section_N10578_N1002A_N10001. It uses REST based interaction for this that is very complementary to OAuth 2.0.

How to check if a table contains an element in Lua?

You can put the values as the table's keys. For example:

function addToSet(set, key)
    set[key] = true
end

function removeFromSet(set, key)
    set[key] = nil
end

function setContains(set, key)
    return set[key] ~= nil
end

There's a more fully-featured example here.

".addEventListener is not a function" why does this error occur?

document.getElementsByClassName returns an array of elements. so may be you want to target a specific index of them: var comment = document.getElementsByClassName('button')[0]; should get you what you want.

Update #1:

var comments = document.getElementsByClassName('button');
var numComments = comments.length;

function showComment() {
  var place = document.getElementById('textfield');
  var commentBox = document.createElement('textarea');
  place.appendChild(commentBox);
}

for (var i = 0; i < numComments; i++) {
  comments[i].addEventListener('click', showComment, false);
}

Update #2: (with removeEventListener incorporated as well)

var comments = document.getElementsByClassName('button');
var numComments = comments.length;

function showComment(e) {
  var place = document.getElementById('textfield');
  var commentBox = document.createElement('textarea');
  place.appendChild(commentBox);
  for (var i = 0; i < numComments; i++) {
    comments[i].removeEventListener('click', showComment, false);
  }
}

for (var i = 0; i < numComments; i++) {
  comments[i].addEventListener('click', showComment, false);
}

How to set DialogFragment's width and height?

Set the Parent layout of Custom dialogue layout to RelativeLayout, get common width and height automatically .

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

Get the previous month's first and last day dates in c#

DateTime now = DateTime.Now;
int prevMonth = now.AddMonths(-1).Month;
int year = now.AddMonths(-1).Year;
int daysInPrevMonth = DateTime.DaysInMonth(year, prevMonth);
DateTime firstDayPrevMonth = new DateTime(year, prevMonth, 1);
DateTime lastDayPrevMonth = new DateTime(year, prevMonth, daysInPrevMonth);
Console.WriteLine("{0} {1}", firstDayPrevMonth.ToShortDateString(),
  lastDayPrevMonth.ToShortDateString());

How to draw a circle with given X and Y coordinates as the middle spot of the circle?

The fillOval fits an oval inside a rectangle, with width=r, height = r you get a circle. If you want fillOval(x,y,r,r) to draw a circle with the center at (x,y) you will have to displace the rectangle by half its width and half its height.

public void drawCenteredCircle(Graphics2D g, int x, int y, int r) {
  x = x-(r/2);
  y = y-(r/2);
  g.fillOval(x,y,r,r);
}

This will draw a circle with center at x,y

How can I render inline JavaScript with Jade / Pug?

Use script tag with the type specified, simply include it before the dot:

script(type="text/javascript").
  if (10 == 10) {
    alert("working");
  }

This will compile to:

<script type="text/javascript">
  if (10 == 10) {
    alert("working");
  }
</script>

Searching for Text within Oracle Stored Procedures

If you use UPPER(text), the like '%lah%' will always return zero results. Use '%LAH%'.

How to trap on UIViewAlertForUnsatisfiableConstraints?

You'll want to add a Symbolic Breakpoint. Apple provides an excellent guide on how to do this.

  1. Open the Breakpoint Navigator cmd+7 (cmd+8 in Xcode 9)
  2. Click the Add button in the lower left
  3. Select Add Symbolic Breakpoint...
  4. Where it says Symbol just type in UIViewAlertForUnsatisfiableConstraints

You can also treat it like any other breakpoint, turning it on and off, adding actions, or log messages.

Difference between EXISTS and IN in SQL?

Based on rule optimizer:

  • EXISTS is much faster than IN, when the sub-query results is very large.
  • IN is faster than EXISTS, when the sub-query results is very small.

Based on cost optimizer:

  • There is no difference.

Oracle pl-sql escape character (for a " ' ")

Your question implies that you're building the INSERT statement up by concatenating strings together. I suggest that this is a poor choice as it leaves you open to SQL injection attacks if the strings are derived from user input. A better choice is to use parameter markers and to bind the values to the markers. If you search for Oracle parameter markers you'll probably find some information for your specific implementation technology (e.g. C# and ADO, Java and JDBC, Ruby and RubyDBI, etc).

Share and enjoy.

Is there an opposite to display:none?

visibility:hidden will hide the element but element is their with DOM. And in case of display:none it'll remove the element from the DOM.

So you have option for element to either hide or unhide. But once you delete it ( I mean display none) it has not clear opposite value. display have several values like display:block,display:inline, display:inline-block and many other. you can check it out from W3C.

How can I access my localhost from my Android device?

Using a USB cable:

(for example, if you use WAMP server):

1) Install your Android drivers on your PC and download portable Android Tethering Reverse Tool and connect your Android device through the Reverse Tool application.

2) Click on WAMP icon > Put Online (after restarting).

3) Open your IP in the Android browser (i.e. http://192.168.1.22 OR http://164.92.124.42 )

To find your local IP address, click Start>Run>cmd and type ipconfig and your IP address will show up in the output.

That's all. Now you can access (open) localhost from Android.

Hash Table/Associative Array in VBA

I think you are looking for the Dictionary object, found in the Microsoft Scripting Runtime library. (Add a reference to your project from the Tools...References menu in the VBE.)

It pretty much works with any simple value that can fit in a variant (Keys can't be arrays, and trying to make them objects doesn't make much sense. See comment from @Nile below.):

Dim d As dictionary
Set d = New dictionary

d("x") = 42
d(42) = "forty-two"
d(CVErr(xlErrValue)) = "Excel #VALUE!"
Set d(101) = New Collection

You can also use the VBA Collection object if your needs are simpler and you just want string keys.

I don't know if either actually hashes on anything, so you might want to dig further if you need hashtable-like performance. (EDIT: Scripting.Dictionary does use a hash table internally.)

Left join only selected columns in R with the merge() function

You can do this by subsetting the data you pass into your merge:

merge(x = DF1, y = DF2[ , c("Client", "LO")], by = "Client", all.x=TRUE)

Or you can simply delete the column after your current merge :)

How to set div width using ng-style

The syntax of ng-style is not quite that. It accepts a dictionary of keys (attribute names) and values (the value they should take, an empty string unsets them) rather than only a string. I think what you want is this:

<div ng-style="{ 'width' : width, 'background' : bgColor }"></div>

And then in your controller:

$scope.width = '900px';
$scope.bgColor = 'red';

This preserves the separation of template and the controller: the controller holds the semantic values while the template maps them to the correct attribute name.

How to remove all callbacks from a Handler?

Define a new handler and runnable:

private Handler handler = new Handler(Looper.getMainLooper());
private Runnable runnable = new Runnable() {
        @Override
        public void run() {
            // Do what ever you want
        }
    };

Call post delayed:

handler.postDelayed(runnable, sleep_time);

Remove your callback from your handler:

handler.removeCallbacks(runnable);

Difference between java.exe and javaw.exe

java.exe is the command where it waits for application to complete untill it takes the next command. javaw.exe is the command which will not wait for the application to complete. you can go ahead with another commands.

open new tab(window) by clicking a link in jquery

Try this:

window.open(url, '_blank');

This will open in new tab (if your code is synchronous and in this case it is. in other case it would open a window)

MultipartException: Current request is not a multipart request

When you are using Postman for multipart request then don't specify a custom Content-Type in Header. So your Header tab in Postman should be empty. Postman will determine form-data boundary. In Body tab of Postman you should select form-data and select file type. You can find related discussion at https://github.com/postmanlabs/postman-app-support/issues/576

Will #if RELEASE work like #if DEBUG does in C#?

RELEASE is not defined, but you can use

#if (!DEBUG)
  ...
#endif

jQuery: how to trigger anchor link's click event

Try the following:

$("#myanchor")[0].click()

As simple as that.

MySQL select with CONCAT condition

Try this:

SELECT * 
  FROM  (
        SELECT neededfield, CONCAT(firstname, ' ', lastname) as firstlast 
        FROM users 
    ) a
WHERE firstlast = "Bob Michael Jones"

Trigger function when date is selected with jQuery UI datepicker

Use the following code:

$(document).ready(function() {
    $('.date-pick').datepicker( {
     onSelect: function(date) {
        alert(date)
     },
    selectWeek: true,
    inline: true,
    startDate: '01/01/2000',
    firstDay: 1,
  });
});

You can adjust the parameters yourself :-)

Error: The 'brew link' step did not complete successfully

I also managed to mess up my NPM and installed packages between these Homebrew versions and no matter how many time I unlinked / linked and uninstalled / installed node it still didn't work.

As it turns out you have to remove NPM from the path otherwise Homebrew won't install it: https://github.com/mxcl/homebrew/blob/master/Library/Formula/node.rb#L117

Hope this will help someone with the same problem and save that hour or so I had to spend looking for the problem...

Accessing localhost of PC from USB connected Android mobile device

I did this on a windows computer and it worked perfectly!

Turn on USB Tethering in your mobile. Type ipconfig in the command prompt in your computer and find the ipv4 for "ethernet adapter local area connection x" (mostly the first one) Now go to your mobile browser, type that ipv4 with the port number of your web application. eg:- 192.168.40.142:1342

It worked with those simple steps!

Finding the last index of an array

Array starts from index 0 and ends at n-1.

static void Main(string[] args)
{
    int[] arr = { 1, 2, 3, 4, 5 };
    int length = arr.Length - 1;   // starts from 0 to n-1

    Console.WriteLine(length);     // this will give the last index.
    Console.Read();
}

How To limit the number of characters in JTextField?

Great question, and it's odd that the Swing toolkit doesn't include this functionality natively for JTextFields. But, here's a great answer from my Udemy.com course "Learn Java Like a Kid":

txtGuess = new JTextField();
txtGuess.addKeyListener(new KeyAdapter() {
    public void keyTyped(KeyEvent e) { 
        if (txtGuess.getText().length() >= 3 ) // limit textfield to 3 characters
            e.consume(); 
    }  
});

This limits the number of characters in a guessing game text field to 3 characters, by overriding the keyTyped event and checking to see if the textfield already has 3 characters - if so, you're "consuming" the key event (e) so that it doesn't get processed like normal.

Video file formats supported in iPhone

Short answer: H.264 MPEG (MP4)

Long answer from Apple.com:

Video formats supported: H.264 video, up to 1.5 Mbps, 640 by 480 pixels, 30 frames per second,

Low-Complexity version of the H.264 Baseline Profile with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats; H.264 video, up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second,

Baseline Profile up to Level 3.0 with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats; MPEG-4 video, up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second,

Simple Profile with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats

http://www.apple.com/iphone/specs.html

Combine a list of data frames into one data frame by row

bind-plot

Code:

library(microbenchmark)

dflist <- vector(length=10,mode="list")
for(i in 1:100)
{
  dflist[[i]] <- data.frame(a=runif(n=260),b=runif(n=260),
                            c=rep(LETTERS,10),d=rep(LETTERS,10))
}


mb <- microbenchmark(
plyr::rbind.fill(dflist),
dplyr::bind_rows(dflist),
data.table::rbindlist(dflist),
plyr::ldply(dflist,data.frame),
do.call("rbind",dflist),
times=1000)

ggplot2::autoplot(mb)

Session:

R version 3.3.0 (2016-05-03)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

> packageVersion("plyr")
[1] ‘1.8.4’
> packageVersion("dplyr")
[1] ‘0.5.0’
> packageVersion("data.table")
[1] ‘1.9.6’

UPDATE: Rerun 31-Jan-2018. Ran on the same computer. New versions of packages. Added seed for seed lovers.

enter image description here

set.seed(21)
library(microbenchmark)

dflist <- vector(length=10,mode="list")
for(i in 1:100)
{
  dflist[[i]] <- data.frame(a=runif(n=260),b=runif(n=260),
                            c=rep(LETTERS,10),d=rep(LETTERS,10))
}


mb <- microbenchmark(
  plyr::rbind.fill(dflist),
  dplyr::bind_rows(dflist),
  data.table::rbindlist(dflist),
  plyr::ldply(dflist,data.frame),
  do.call("rbind",dflist),
  times=1000)

ggplot2::autoplot(mb)+theme_bw()


R version 3.4.0 (2017-04-21)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

> packageVersion("plyr")
[1] ‘1.8.4’
> packageVersion("dplyr")
[1] ‘0.7.2’
> packageVersion("data.table")
[1] ‘1.10.4’

UPDATE: Rerun 06-Aug-2019.

enter image description here

set.seed(21)
library(microbenchmark)

dflist <- vector(length=10,mode="list")
for(i in 1:100)
{
  dflist[[i]] <- data.frame(a=runif(n=260),b=runif(n=260),
                            c=rep(LETTERS,10),d=rep(LETTERS,10))
}


mb <- microbenchmark(
  plyr::rbind.fill(dflist),
  dplyr::bind_rows(dflist),
  data.table::rbindlist(dflist),
  plyr::ldply(dflist,data.frame),
  do.call("rbind",dflist),
  purrr::map_df(dflist,dplyr::bind_rows),
  times=1000)

ggplot2::autoplot(mb)+theme_bw()

R version 3.6.0 (2019-04-26)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.2 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/openblas/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/libopenblasp-r0.2.20.so

packageVersion("plyr")
packageVersion("dplyr")
packageVersion("data.table")
packageVersion("purrr")

>> packageVersion("plyr")
[1] ‘1.8.4’
>> packageVersion("dplyr")
[1] ‘0.8.3’
>> packageVersion("data.table")
[1] ‘1.12.2’
>> packageVersion("purrr")
[1] ‘0.3.2’

How to find out mySQL server ip address from phpmyadmin

MySQL doesn't care what IP its on. Closest you could get would be hostname:

select * from GLOBAL_variables where variable_name like 'hostname';

Input type DateTime - Value format?

with momentjs i use

moment(value).format("YYYY-MM-DDTHH:mm:ss")

Maintain aspect ratio of div but fill screen width and height in CSS?

Use the new CSS viewport units vw and vh (viewport width / viewport height)

FIDDLE

Resize vertically and horizontally and you'll see that the element will always fill the maximum viewport size without breaking the ratio and without scrollbars!

(PURE) CSS

div
{
    width: 100vw; 
    height: 56.25vw; /* height:width ratio = 9/16 = .5625  */
    background: pink;
    max-height: 100vh;
    max-width: 177.78vh; /* 16/9 = 1.778 */
    margin: auto;
    position: absolute;
    top:0;bottom:0; /* vertical center */
    left:0;right:0; /* horizontal center */
}

_x000D_
_x000D_
* {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
div {_x000D_
  width: 100vw;_x000D_
  height: 56.25vw;_x000D_
  /* 100/56.25 = 1.778 */_x000D_
  background: pink;_x000D_
  max-height: 100vh;_x000D_
  max-width: 177.78vh;_x000D_
  /* 16/9 = 1.778 */_x000D_
  margin: auto;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  /* vertical center */_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  /* horizontal center */_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

If you want to use a maximum of say 90% width and height of the viewport: FIDDLE

_x000D_
_x000D_
* {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
div {_x000D_
  width: 90vw;_x000D_
  /* 90% of viewport vidth */_x000D_
  height: 50.625vw;_x000D_
  /* ratio = 9/16 * 90 = 50.625 */_x000D_
  background: pink;_x000D_
  max-height: 90vh;_x000D_
  max-width: 160vh;_x000D_
  /* 16/9 * 90 = 160 */_x000D_
  margin: auto;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

Also, browser support is pretty good too: IE9+, FF, Chrome, Safari- caniuse

How to search text using php if ($text contains "World")

This might be what you are looking for:

<?php

$text = 'This is a Simple text.';

// this echoes "is is a Simple text." because 'i' is matched first
echo strpbrk($text, 'mi');

// this echoes "Simple text." because chars are case sensitive
echo strpbrk($text, 'S');
?>

Is it?

Or maybe this:

<?php
$mystring = 'abc';
$findme   = 'a';
$pos = strpos($mystring, $findme);

// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {
    echo "The string '$findme' was not found in the string '$mystring'";
} else {
    echo "The string '$findme' was found in the string '$mystring'";
    echo " and exists at position $pos";
}
?>

Or even this

<?php
$email  = '[email protected]';
$domain = strstr($email, '@');
echo $domain; // prints @example.com

$user = strstr($email, '@', true); // As of PHP 5.3.0
echo $user; // prints name
?>

You can read all about them in the documentation here:

http://php.net/manual/en/book.strings.php

How to add a column in TSQL after a specific column?

This is absolutely possible. Although you shouldn't do it unless you know what you are dealing with. Took me about 2 days to figure it out. Here is a stored procedure where i enter: ---database name (schema name is "_" for readability) ---table name ---column ---column data type (column added is always null, otherwise you won't be able to insert) ---the position of the new column.

Since I'm working with tables from SAM toolkit (and some of them have > 80 columns) , the typical variable won't be able to contain the query. That forces the need of external file. Now be careful where you store that file and who has access on NTFS and network level.

Cheers!

USE [master]
GO
/****** Object:  StoredProcedure [SP_Set].[TrasferDataAtColumnLevel]    Script Date: 8/27/2014 2:59:30 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE [SP_Set].[TrasferDataAtColumnLevel]
(
    @database varchar(100),
    @table varchar(100),
    @column varchar(100),
    @position int,
    @datatype varchar(20)    
)
AS
BEGIN
set nocount on
exec  ('
declare  @oldC varchar(200), @oldCDataType varchar(200), @oldCLen int,@oldCPos int
create table Test ( dummy int)
declare @columns varchar(max) = ''''
declare @columnVars varchar(max) = ''''
declare @columnsDecl varchar(max) = ''''
declare @printVars varchar(max) = ''''

DECLARE MY_CURSOR CURSOR LOCAL STATIC READ_ONLY FORWARD_ONLY FOR 
select column_name, data_type, character_maximum_length, ORDINAL_POSITION  from ' + @database + '.INFORMATION_SCHEMA.COLUMNS where table_name = ''' + @table + '''
OPEN MY_CURSOR FETCH NEXT FROM MY_CURSOR INTO @oldC, @oldCDataType, @oldCLen, @oldCPos WHILE @@FETCH_STATUS = 0 BEGIN

if(@oldCPos = ' + @position + ')
begin
    exec(''alter table Test add [' + @column + '] ' + @datatype + ' null'')
end

if(@oldCDataType != ''timestamp'')
begin

    set @columns += @oldC + '' , '' 
    set @columnVars += ''@'' + @oldC + '' , ''

    if(@oldCLen is null)
    begin
        if(@oldCDataType != ''uniqueidentifier'')
        begin
            set @printVars += '' print convert('' + @oldCDataType + '',@'' + @oldC + '')'' 
            set @columnsDecl += ''@'' + @oldC + '' '' + @oldCDataType + '', '' 
            exec(''alter table Test add ['' + @oldC + ''] '' + @oldCDataType + '' null'')
        end
        else
        begin
            set @printVars += '' print convert(varchar(50),@'' + @oldC + '')'' 
            set @columnsDecl += ''@'' + @oldC + '' '' + @oldCDataType + '', '' 
            exec(''alter table Test add ['' + @oldC + ''] '' + @oldCDataType + '' null'')
        end
    end
    else
    begin 
        if(@oldCLen < 0)
        begin
            set @oldCLen = 4000
        end
        set @printVars += '' print @'' + @oldC 
        set @columnsDecl += ''@'' + @oldC + '' '' + @oldCDataType + ''('' + convert(character,@oldCLen) + '') , '' 
        exec(''alter table Test add ['' + @oldC + ''] '' + @oldCDataType + ''('' + @oldCLen + '') null'')
    end
end

if exists (select column_name from INFORMATION_SCHEMA.COLUMNS where table_name = ''Test'' and column_name = ''dummy'')
begin
    alter table Test drop column dummy
end

FETCH NEXT FROM MY_CURSOR INTO  @oldC, @oldCDataType, @oldCLen, @oldCPos END CLOSE MY_CURSOR DEALLOCATE MY_CURSOR

set @columns = reverse(substring(reverse(@columns), charindex('','',reverse(@columns)) +1, len(@columns)))
set @columnVars = reverse(substring(reverse(@columnVars), charindex('','',reverse(@columnVars)) +1, len(@columnVars)))
set @columnsDecl = reverse(substring(reverse(@columnsDecl), charindex('','',reverse(@columnsDecl)) +1, len(@columnsDecl)))
set @columns = replace(replace(REPLACE(@columns, ''       '', ''''), char(9) + char(9),'' ''), char(9), '''')
set @columnVars = replace(replace(REPLACE(@columnVars, ''       '', ''''), char(9) + char(9),'' ''), char(9), '''')
set @columnsDecl = replace(replace(REPLACE(@columnsDecl, ''  '', ''''), char(9) + char(9),'' ''),char(9), '''')
set @printVars = REVERSE(substring(reverse(@printVars), charindex(''+'',reverse(@printVars))+1, len(@printVars))) 

create table query (id int identity(1,1), string varchar(max))

insert into query values  (''declare '' + @columnsDecl + ''
DECLARE MY_CURSOR CURSOR LOCAL STATIC READ_ONLY FORWARD_ONLY FOR '')

insert into query values   (''select '' + @columns + '' from ' + @database + '._.' + @table + ''')

insert into query values  (''OPEN MY_CURSOR FETCH NEXT FROM MY_CURSOR INTO '' + @columnVars + '' WHILE @@FETCH_STATUS = 0 BEGIN '')

insert into query values   (@printVars )

insert into query values   ( '' insert into Test ('')
insert into query values   (@columns) 
insert into query values   ( '') values ( '' + @columnVars + '')'')

insert into query values  (''FETCH NEXT FROM MY_CURSOR INTO  '' + @columnVars + '' END CLOSE MY_CURSOR DEALLOCATE MY_CURSOR'')

declare @path varchar(100) = ''C:\query.sql''
declare @query varchar(500) = ''bcp "select string from query order by id" queryout '' + @path + '' -t, -c -S  '' + @@servername +  '' -T''

exec master..xp_cmdshell @query

set @query  = ''sqlcmd -S '' + @@servername + '' -i '' + @path

EXEC xp_cmdshell  @query

set @query = ''del ''  + @path

exec xp_cmdshell @query

drop table ' + @database + '._.' + @table + '

select * into ' + @database + '._.' + @table + ' from Test 

drop table query
drop table Test  ')

END

CSS Margin: 0 is not setting to 0

h1 {
margin-top:0;
padding-top: 0;}

It' s just a misunderstanding with h1 tag. You have to set h1 tag margin-top and padding-top to 0 (zero).

Declare a dictionary inside a static class

Old question, but I found this useful. Turns out, there's also a specialized class for a Dictionary using a string for both the key and the value:

private static readonly StringDictionary SegmentSyntaxErrorCodes = new StringDictionary
{
    { "1", "Unrecognized segment ID" },
    { "2", "Unexpected segment" }
};

Edit: Per Chris's comment below, using Dictionary<string, string> over StringDictionary is generally preferred but will depend on your situation. If you're dealing with an older code base, you might be limited to the StringDictionary. Also, note that the following line:

myDict["foo"]

will return null if myDict is a StringDictionary, but an exception will be thrown in case of Dictionary<string, string>. See the SO post he mentioned for more information, which is the source of this edit.

'numpy.float64' object is not iterable

numpy.linspace() gives you a one-dimensional NumPy array. For example:

>>> my_array = numpy.linspace(1, 10, 10)
>>> my_array
array([  1.,   2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.])

Therefore:

for index,point in my_array

cannot work. You would need some kind of two-dimensional array with two elements in the second dimension:

>>> two_d = numpy.array([[1, 2], [4, 5]])
>>> two_d
array([[1, 2], [4, 5]])

Now you can do this:

>>> for x, y in two_d:
    print(x, y)

1 2
4 5

Threading Example in Android

One of Androids powerful feature is the AsyncTask class.

To work with it, you have to first extend it and override doInBackground(...). doInBackground automatically executes on a worker thread, and you can add some listeners on the UI Thread to get notified about status update, those functions are called: onPreExecute(), onPostExecute() and onProgressUpdate()

You can find a example here.

Refer to below post for other alternatives:

Handler vs AsyncTask vs Thread

How to "Open" and "Save" using java

You want to use a JFileChooser object. It will open and be modal, and block in the thread that opened it until you choose a file.

Open:

JFileChooser fileChooser = new JFileChooser();
if (fileChooser.showOpenDialog(modalToComponent) == JFileChooser.APPROVE_OPTION) {
  File file = fileChooser.getSelectedFile();
  // load from file
}

Save:

JFileChooser fileChooser = new JFileChooser();
if (fileChooser.showSaveDialog(modalToComponent) == JFileChooser.APPROVE_OPTION) {
  File file = fileChooser.getSelectedFile();
  // save to file
}

There are more options you can set to set the file name extension filter, or the current directory. See the API for the javax.swing.JFileChooser for details. There is also a page for "How to Use File Choosers" on Oracle's site:

http://download.oracle.com/javase/tutorial/uiswing/components/filechooser.html

:last-child not working as expected?

:last-child will not work if the element is not the VERY LAST element

In addition to Harry's answer, I think it's crucial to add/emphasize that :last-child will not work if the element is not the VERY LAST element in a container. For whatever reason it took me hours to realize that, and even though Harry's answer is very thorough I couldn't extract that information from "The last-child selector is used to select the last child element of a parent."

Suppose this is my selector: a:last-child {}

This works:

<div>
    <a></a>
    <a>This will be selected</a>
</div>

This doesn't:

<div>
    <a></a>
    <a>This will no longer be selected</a>
    <div>This is now the last child :'( </div>
</div>

It doesn't because the a element is not the last element inside its parent.

It may be obvious, but it was not for me...

How to find whether a number belongs to a particular range in Python?

I would use the numpy library, which would allow you to do this for a list of numbers as well:

from numpy import array
a = array([1, 2, 3, 4, 5, 6,])
a[a < 2]

Convert JSON array to an HTML table in jQuery

A still shorter way

$.makeTable = function (mydata) {
            if (mydata.length <= 0) return "";
           return $('<table border=1>').append("<tr>" + $.map(mydata[0], function (val, key) {
                return "<th>" + key + "</th>";
            }).join("\n") + "</tr>").append($.map(mydata, function (index, value) {
                return "<tr>" + $.map(index, function (val, key) {
                    return "<td>" + val + "</td>";
                }).join("\n") + "</tr>";
            }).join("\n"));
        };

Import data.sql MySQL Docker Container

Just write docker ps and get the container id and then write the following;

docker exec -i your_container_id mysql -u root -p123456 your_db_name < /Users/your_pc/your_project_folder/backup.sql

How do I fix the indentation of selected lines in Visual Studio

Selecting the text to fix, and CtrlK, CtrlF shortcut certainly works. However, I generally find that if a particular method (for instance) has it's indentation messed up, simply removing the closing brace of the method, and re-adding, in fact fixes the indentation anyway, thereby doing without the need to select the code before hand, ergo is quicker. ymmv.

Compiling with g++ using multiple cores

You can do this with make - with gnu make it is the -j flag (this will also help on a uniprocessor machine).

For example if you want 4 parallel jobs from make:

make -j 4

You can also run gcc in a pipe with

gcc -pipe

This will pipeline the compile stages, which will also help keep the cores busy.

If you have additional machines available too, you might check out distcc, which will farm compiles out to those as well.

Twitter Bootstrap 3: how to use media queries?

If you're using LESS or SCSS/SASS and you're using a LESS/SCSS version of Bootstrap, you can use variables as well, provided you have access to them. A LESS translation of @full-decent's answer would be as follows:

@media(max-width: @screen-xs-max){}
@media(min-width: @screen-sm-min){}  /* deprecated: @screen-tablet, or @screen-sm */
@media(min-width: @screen-md-min){}  /* deprecated: @screen-desktop, or @screen-md */
@media(min-width: @screen-lg-min){}  /* deprecated: @screen-lg-desktop, or @screen-lg */

There are also variables for @screen-sm-max and @screen-md-max, which are 1 pixel less than @screen-md-min and @screen-lg-min, respectively, typically for use with @media(max-width).

EDIT: If you're using SCSS/SASS, variables start with a $ instead of a @, so it'd be $screen-xs-max etc.

Extract MSI from EXE

Quick List: There are a number of common types of setup.exe files. Here are some of them in a "short-list". More fleshed-out details here (towards bottom).

Setup.exe Extract: (various flavors to try)

setup.exe /a
setup.exe /s /extract_all
setup.exe /s /extract_all:[path]
setup.exe /stage_only
setup.exe /extract "C:\My work"
setup.exe /x
setup.exe /x [path]
setup.exe /s /x /b"C:\FolderInWhichMSIWillBeExtracted" /v"/qn"

dark.exe -x outputfolder setup.exe

dark.exe is a WiX binary - install WiX to extract a WiX setup.exe (as of now). More (section 4).

There is always:

setup.exe /?

MSI Extract: msiexec.exe / File.msi extraction:

 msiexec /a File.msi
 msiexec /a File.msi TARGETDIR=C:\MyInstallPoint /qn

Many Setup Tools: It is impossible to cover all the different kinds of possible setup.exe files. They might feature all kinds of different command line switches. There are so many possible tools that can be used. (non-MSI,MSI, admin-tools, multi-platform, etc...).

NSIS / Inno: Commmon, free tools such as Inno Setup seem to make extraction hard (unofficial unpacker, not tried by me, run by virustotal.com). Whereas NSIS seems to use regular archives that standard archive software (7-zip et al) can open and extract.

General Tricks: One trick is to launch the setup.exe and look in the 1) system's temp folder for extracted files. Another trick is to use 2) 7-Zip, WinRAR, WinZip or similar archive tools to see if they can read the format. Some claim success by 3) opening the setup.exe in Visual Studio. Not a technique I use. 4) And there is obviously application repackaging - capturing the changes done to a computer after a setup has run and clean it up - requires a special tool (most of the free ones come and go, Advanced Installer Architect and AdminStudio are big players).


UPDATE: A quick presentation of various deployment tools used to create installers: How to create windows installer (comprehensive links).

And a simpler list view of the most used development tools as of now (2018), for quicker reading and overview.

And for safekeeping:


Just a disclaimer: A setup.exe file can contain an embedded MSI, it can be a legacy style (non-MSI) installer or it can be just a regular executable with no means of extraction whatsoever. The "discussion" below first presents the use of admin images for MSI files and how to extract MSI files from setup.exe files. Then it provides some links to handle other types of setup.exe files. Also see the comments section.

UPDATE: a few sections have now been added directly below, before the description of MSI file extract using administrative installation. Most significantly a blurb about extracting WiX setup.exe bundles (new kid on the block). Remember that a "last resort" to find extracted setup files, is to launch the installer and then look for extracted files in the temp folder (Hold down Windows Key, tap R, type %temp% or %tmp% and hit Enter) - try the other options first though - for reliability reasons.

Apologies for the "generalized mess" with all this heavy inter-linking. I do believe that you will find what you need if you dig enough in the links, but the content should really be cleaned up and organized better.

General links:

Extract content:

Vendor links:


WiX Toolkit & Burn Bundles (setup.exe files)

Tech Note: The WiX toolkit now delivers setup.exe files built with the bootstrapper tool Burn that you need the toolkit's own dark.exe decompiler to extract. Burn is used to build setup.exe files that can install several embedded MSI or executables in a specified sequence. Here is a sample extraction command:

dark.exe -x outputfolder MySetup.exe

Before you can run such an extraction, some prerequisite steps are required:

  1. Download and install the WiX toolkit (linking to a previous answer with some extra context information on WiX - as well as the download link).
  2. After installing WiX, just open a command prompt, CD to the folder where the setup.exe resides. Then specify the above command and press Enter
  3. The output folder will contain a couple of sub-folders containing both extracted MSI and EXE files and manifests and resource file for the Burn GUI (if any existed in the setup.exe file in the first place of course).
  4. You can now, in turn, extract the contents of the extracted MSI files (or EXE files). For an MSI that would mean running an admin install - as described below.

There is built-in MSI support for file extraction (admin install)

MSI or Windows Installer has built-in support for this - the extraction of files from an MSI file. This is called an administrative installation. It is basically intended as a way to create a network installation point from which the install can be run on many target computers. This ensures that the source files are always available for any repair operations.

Note that running an admin install versus using a zip tool to extract the files is very different! The latter will not adjust the media layout of the media table so that the package is set to use external source files - which is the correct way. Always prefer to run the actual admin install over any hacky zip extractions. As to compression, there are actually three different compression algorithms used for the cab files inside the MSI file format: MSZip, LZX, and Storing (uncompressed). All of these are handled correctly by doing an admin install.

Important: Windows Installer caches installed MSI files on the system for repair, modify and uninstall scenarios. Starting with Windows 7 (MSI version 5) the MSI files are now cached full size to avoid breaking the file signature that prevents the UAC prompt on setup launch (a known Vista problem). This may cause a tremendous increase in disk space consumption (several gigabytes for some systems). To prevent caching a huge MSI file, you should run an admin-install of the package before installing. This is how a company with proper deployment in a managed network would do things, and it will strip out the cab files and make a network install point with a small MSI file and files besides it.


Admin-installs have many uses

It is recommended to read more about admin-installs since it is a useful concept, and I have written a post on stackoverflow: What is the purpose of administrative installation initiated using msiexec /a?.

In essence the admin install is important for:

  • Extracting and inspecting the installer files
    • To get an idea of what is actually being installed and where
    • To ensure that the files look trustworthy and secure (no viruses - malware and viruses can still hide inside the MSI file though)
  • Deployment via systems management software (for example SCCM)
  • Corporate application repackaging
  • Repair, modify and self-repair operations
  • Patching & upgrades
  • MSI advertisement (among other details this involves the "run from source" feature where you can run directly from a network share and you only install shortcuts and registry data)
  • A number of other smaller details

Please read the stackoverflow post linked above for more details. It is quite an important concept for system administrators, application packagers, setup developers, release managers, and even the average user to see what they are installing etc...


Admin-install, practical how-to

You can perform an admin-install in a few different ways depending on how the installer is delivered. Essentially it is either delivered as an MSI file or wrapped in an setup.exe file.

Run these commands from an elevated command prompt, and follow the instructions in the GUI for the interactive command lines:

  • MSI files:

    msiexec /a File.msi
    

    that's to run with GUI, you can do it silently too:

    msiexec /a File.msi TARGETDIR=C:\MyInstallPoint /qn
    
  • setup.exe files:

    setup.exe /a
    

A setup.exe file can also be a legacy style setup (non-MSI) or the dreaded Installscript MSI file type - a well known buggy Installshield project type with hybrid non-standards-compliant MSI format. It is essentially an MSI with a custom, more advanced GUI, but it is also full of bugs.

For legacy setup.exe files the /a will do nothing, but you can try the /extract_all:[path] switch as explained in this pdf. It is a good reference for silent installation and other things as well. Another resource is this list of Installshield setup.exe command line parameters.

MSI patch files (*.MSP) can be applied to an admin image to properly extract its files. 7Zip will also be able to extract the files, but they will not be properly formatted.

Finally - the last resort - if no other way works, you can get hold of extracted setup files by cleaning out the temp folder on your system, launch the setup.exe interactively and then wait for the first dialog to show up. In most cases the installer will have extracted a bunch of files to a temp folder. Sometimes the files are plain, other times in CAB format, but Winzip, 7Zip or even Universal Extractor (haven't tested this product) - may be able to open these.

How do I convert a Swift Array to a String?

Swift 3

["I Love","Swift"].joined(separator:" ") // previously joinWithSeparator(" ")

Convert string to datetime in vb.net

Pass the decode pattern to ParseExact

Dim d as string = "201210120956"
Dim dt = DateTime.ParseExact(d, "yyyyMMddhhmm", Nothing)

ParseExact is available only from Net FrameWork 2.0.
If you are still on 1.1 you could use Parse, but you need to provide the IFormatProvider adequate to your string

Send POST request with JSON data using Volley

You can also send data by overriding getBody() method of JsonObjectRequest class. As shown below.

    @Override
    public byte[] getBody()
    {

        JSONObject jsonObject = new JSONObject();
        String body = null;
        try
        {
            jsonObject.put("username", "user123");
            jsonObject.put("password", "Pass123");

            body = jsonObject.toString();
        } catch (JSONException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try
        {
            return body.toString().getBytes("utf-8");
        } catch (UnsupportedEncodingException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

NSRange to Range<String.Index>

extension StringProtocol where Index == String.Index {

    func nsRange(of string: String) -> NSRange? {
        guard let range = self.range(of: string) else {  return nil }
        return NSRange(range, in: self)
    }
}

How to create a List with a dynamic object type

It appears you might be a bit confused as to how the .Add method works. I will refer directly to your code in my explanation.

Basically in C#, the .Add method of a List of objects does not COPY new added objects into the list, it merely copies a reference to the object (it's address) into the List. So the reason every value in the list is pointing to the same value is because you've only created 1 new DyObj. So your list essentially looks like this.

DyObjectsList[0] = &DyObj; // pointing to DyObj
DyObjectsList[1] = &DyObj; // pointing to the same DyObj
DyObjectsList[2] = &DyObj; // pointing to the same DyObj

...

The easiest way to fix your code is to create a new DyObj for every .Add. Putting the new inside of the block with the .Add would accomplish this goal in this particular instance.

var DyObjectsList = new List<dynamic>; 
if (condition1) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = true; 
    DyObj.Message = "Message 1"; 
    DyObjectsList .Add(DyObj); 
} 
if (condition2) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = false; 
    DyObj.Message = "Message 2"; 
    DyObjectsList .Add(DyObj); 
} 

your resulting List essentially looks like this

DyObjectsList[0] = &DyObj0; // pointing to a DyObj
DyObjectsList[1] = &DyObj1; // pointing to a different DyObj
DyObjectsList[2] = &DyObj2; // pointing to another DyObj

Now in some other languages this approach wouldn't work, because as you leave the block, the objects declared in the scope of the block could go out of scope and be destroyed. Thus you would be left with a collection of pointers, pointing to garbage.

However in C#, if a reference to the new DyObjs exists when you leave the block (and they do exist in your List because of the .Add operation) then C# does not release the memory associated with that pointer. Therefore the Objects you created in that block persist and your List contains pointers to valid objects and your code works.

C multi-line macro: do/while(0) vs scope block

Andrey Tarasevich provides the following explanation:

  1. On Google Groups
  2. On bytes.com

[Minor changes to formatting made. Parenthetical annotations added in square brackets []].

The whole idea of using 'do/while' version is to make a macro which will expand into a regular statement, not into a compound statement. This is done in order to make the use of function-style macros uniform with the use of ordinary functions in all contexts.

Consider the following code sketch:

if (<condition>)
  foo(a);
else
  bar(a);

where foo and bar are ordinary functions. Now imagine that you'd like to replace function foo with a macro of the above nature [named CALL_FUNCS]:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

Now, if your macro is defined in accordance with the second approach (just { and }) the code will no longer compile, because the 'true' branch of if is now represented by a compound statement. And when you put a ; after this compound statement, you finished the whole if statement, thus orphaning the else branch (hence the compilation error).

One way to correct this problem is to remember not to put ; after macro "invocations":

if (<condition>)
  CALL_FUNCS(a)
else
  bar(a);

This will compile and work as expected, but this is not uniform. The more elegant solution is to make sure that macro expand into a regular statement, not into a compound one. One way to achieve that is to define the macro as follows:

#define CALL_FUNCS(x) \
do { \
  func1(x); \
  func2(x); \
  func3(x); \
} while (0)

Now this code:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

will compile without any problems.

However, note the small but important difference between my definition of CALL_FUNCS and the first version in your message. I didn't put a ; after } while (0). Putting a ; at the end of that definition would immediately defeat the entire point of using 'do/while' and make that macro pretty much equivalent to the compound-statement version.

I don't know why the author of the code you quoted in your original message put this ; after while (0). In this form both variants are equivalent. The whole idea behind using 'do/while' version is not to include this final ; into the macro (for the reasons that I explained above).

Can I create links with 'target="_blank"' in Markdown?

You can do this via native javascript code like so:

 
var pattern = /a href=/g;
var sanitizedMarkDownText = rawMarkDownText.replace(pattern,"a target='_blank' href=");

JSFiddle Code

How to shutdown a Spring Boot Application in a correct way?

They are many ways to shutdown a spring application. One is to call close() on the ApplicationContext:

ApplicationContext ctx =
    SpringApplication.run(HelloWorldApplication.class, args);
// ...
ctx.close()

Your question suggest you want to close your application by doing Ctrl+C, that is frequently used to terminate a command. In this case...

Use endpoints.shutdown.enabled=true is not the best recipe. It means you expose an end-point to terminate your application. So, depending on your use case and your environment, you will have to secure it...

Ctrl+C should work very well in your case. I assume your issue is caused by the ampersand (&) More explanation:

A Spring Application Context may have register a shutdown hook with the JVM runtime. See ApplicationContext documentation.

I don't know if Spring Boot configure this hook automatically as you said. I assume it is.

On Ctrl+C, your shell sends an INT signal to the foreground application. It means "please interrupt your execution". The application can trap this signal and do cleanup before its termination (the hook registered by Spring), or simply ignore it (bad).

nohup is command that execute the following program with a trap to ignore the HUP signal. HUP is used to terminate program when you hang up (close your ssh connexion for example). Moreover it redirects outputs to avoid that your program blocks on a vanished TTY. nohupdoes NOT ignore INT signal. So it does NOT prevent Ctrl+C to work.

I assume your issue is caused by the ampersand (&), not by nohup. Ctrl+C sends a signal to the foreground processes. The ampersand causes your application to be run in background. One solution: do

kill -INT pid

Use kill -9 or kill -KILL is bad because the application (here the JVM) cannot trap it to terminate gracefully.

Another solution is to bring back your application in foreground. Then Ctrl+C will work. Have a look on Bash Job control, more precisely on fg.

Identifying and solving javax.el.PropertyNotFoundException: Target Unreachable

1. Target Unreachable, identifier 'bean' resolved to null

This boils down to that the managed bean instance itself could not be found by exactly that identifier (managed bean name) in EL like so #{bean}.

Identifying the cause can be broken down into three steps:

a. Who's managing the bean?
b. What's the (default) managed bean name?
c. Where's the backing bean class?

1a. Who's managing the bean?

First step would be checking which bean management framework is responsible for managing the bean instance. Is it CDI via @Named? Or is it JSF via @ManagedBean? Or is it Spring via @Component? Can you make sure that you're not mixing multiple bean management framework specific annotations on the very same backing bean class? E.g. @Named @ManagedBean, @Named @Component, or @ManagedBean @Component. This is wrong. The bean must be managed by at most one bean management framework and that framework must be properly configured. If you already have no idea which to choose, head to Backing beans (@ManagedBean) or CDI Beans (@Named)? and Spring JSF integration: how to inject a Spring component/service in JSF managed bean?

In case it's CDI who's managing the bean via @Named, then you need to make sure of the following:

  • CDI 1.0 (Java EE 6) requires an /WEB-INF/beans.xml file in order to enable CDI in WAR. It can be empty or it can have just the following content:

      <?xml version="1.0" encoding="UTF-8"?>
      <beans xmlns="http://java.sun.com/xml/ns/javaee" 
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                                 http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
      </beans>
    
  • CDI 1.1 (Java EE 7) without any beans.xml, or an empty beans.xml file, or with the above CDI 1.0 compatible beans.xml will behave the same as CDI 1.0. When there's a CDI 1.1 compatible beans.xml with an explicit version="1.1", then it will by default only register @Named beans with an explicit CDI scope annotation such as @RequestScoped, @ViewScoped, @SessionScoped, @ApplicationScoped, etc. In case you intend to register all beans as CDI managed beans, even those without an explicit CDI scope, use the below CDI 1.1 compatible /WEB-INF/beans.xml with bean-discovery-mode="all" set (the default is bean-discovery-mode="annotated").

      <?xml version="1.0" encoding="UTF-8"?>
      <beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
                                 http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
             version="1.1" bean-discovery-mode="all">
      </beans>
    
  • When using CDI 1.1+ with bean-discovery-mode="annotated" (default), make sure that you didn't accidentally import a JSF scope such as javax.faces.bean.RequestScoped instead of a CDI scope javax.enterprise.context.RequestScoped. Watch out with IDE autocomplete.

  • When using Mojarra 2.3.0-2.3.2 and CDI 1.1+ with bean-discovery-mode="annotated" (default), then you need to upgrade Mojarra to 2.3.3 or newer due to a bug. In case you can't upgrade, then you need either to set bean-discovery-mode="all" in beans.xml, or to put the JSF 2.3 specific @FacesConfig annotation on an arbitrary class in the WAR (generally some sort of an application scoped startup class).

  • When using JSF 2.3 on a Servlet 4.0 container with a web.xml declared conform Servlet 4.0, then you need to explicitly put the JSF 2.3 specific @FacesConfig annotation on an arbitrary class in the WAR (generally some sort of an application scoped startup class). This is not necessary in Servlet 3.x.

  • Non-Java EE containers like Tomcat and Jetty doesn't ship with CDI bundled. You need to install it manually. It's a bit more work than just adding the library JAR(s). For Tomcat, make sure that you follow the instructions in this answer: How to install and use CDI on Tomcat?

  • Your runtime classpath is clean and free of duplicates in CDI API related JARs. Make sure that you're not mixing multiple CDI implementations (Weld, OpenWebBeans, etc). Make sure that you don't provide another CDI or even Java EE API JAR file along webapp when the target container already bundles CDI API out the box.

  • If you're packaging CDI managed beans for JSF views in a JAR, then make sure that the JAR has at least a valid /META-INF/beans.xml (which can be kept empty).


In case it's JSF who's managing the bean via the since 2.3 deprecated @ManagedBean, and you can't migrate to CDI, then you need to make sure of the following:

  • The faces-config.xml root declaration is compatible with JSF 2.0. So the XSD file and the version must at least specify JSF 2.0 or higher and thus not 1.x.

      <faces-config
          xmlns="http://java.sun.com/xml/ns/javaee"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"
          version="2.0">
    

    For JSF 2.1, just replace 2_0 and 2.0 by 2_1 and 2.1 respectively.

    If you're on JSF 2.2 or higher, then make sure you're using xmlns.jcp.org namespaces instead of java.sun.com over all place.

      <faces-config
          xmlns="http://xmlns.jcp.org/xml/ns/javaee"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
          version="2.2">
    

    For JSF 2.3, just replace 2_2 and 2.2 by 2_3 and 2.3 respectively.

  • You didn't accidentally import javax.annotation.ManagedBean instead of javax.faces.bean.ManagedBean. Watch out with IDE autocomplete, Eclipse is known to autosuggest the wrong one as first item in the list.

  • You didn't override the @ManagedBean by a JSF 1.x style <managed-bean> entry in faces-config.xml on the very same backing bean class along with a different managed bean name. This one will have precedence over @ManagedBean. Registering a managed bean in faces-config.xml is not necessary since JSF 2.0, just remove it.

  • Your runtime classpath is clean and free of duplicates in JSF API related JARs. Make sure that you're not mixing multiple JSF implementations (Mojarra and MyFaces). Make sure that you don't provide another JSF or even Java EE API JAR file along webapp when the target container already bundles JSF API out the box. See also "Installing JSF" section of our JSF wiki page for JSF installation instructions. In case you intend to upgrade container-bundled JSF from the WAR on instead of in container itself, make sure that you've instructed the target container to use WAR-bundled JSF API/impl.

  • If you're packaging JSF managed beans in a JAR, then make sure that the JAR has at least a JSF 2.0 compatible /META-INF/faces-config.xml. See also How to reference JSF managed beans which are provided in a JAR file?

  • If you're actually using the jurassic JSF 1.x, and you can't upgrade, then you need to register the bean via <managed-bean> in faces-config.xml instead of @ManagedBean. Don't forget to fix your project build path as such that you don't have JSF 2.x libraries anymore (so that the @ManagedBean annotation wouldn't confusingly successfully compile).


In case it's Spring who's managing the bean via @Component, then you need to make sure of the following:

  • Spring is being installed and integrated as per its documentation. Importantingly, you need to at least have this in web.xml:

      <listener>
          <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
      </listener>
    

    And this in faces-config.xml:

      <application>
          <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
      </application>
    
  • (above is all I know with regard to Spring — I don't do Spring — feel free to edit/comment with other probable Spring related causes; e.g. some XML configuration related trouble)


In case it's a repeater component who's managing the (nested) bean via its var attribute (e.g. <h:dataTable var="item">, <ui:repeat var="item">, <p:tabView var="item">, etc) and you actually got a "Target Unreachable, identifier 'item' resolved to null", then you need to make sure of the following:

  • The #{item} is not referenced in binding attribtue of any child component. This is incorrect as binding attribute runs during view build time, not during view render time. Moreover, there's physically only one component in the component tree which is simply reused during every iteration round. In other words, you should actually be using binding="#{bean.component}" instead of binding="#{item.component}". But much better is to get rid of component bining to bean altogether and investigate/ask the proper approach for the problem you thought to solve this way. See also How does the 'binding' attribute work in JSF? When and how should it be used?


1b. What's the (default) managed bean name?

Second step would be checking the registered managed bean name. JSF and Spring use conventions conform JavaBeans specification while CDI has exceptions depending on CDI impl/version.

  • A FooBean backing bean class like below,

      @Named
      public class FooBean {}
    

    will in all bean management frameworks have a default managed bean name of #{fooBean}, as per JavaBeans specification.

  • A FOOBean backing bean class like below,

      @Named
      public class FOOBean {}
    

    whose unqualified classname starts with at least two capitals will in JSF and Spring have a default managed bean name of exactly the unqualified class name #{FOOBean}, also conform JavaBeans specificiation. In CDI, this is also the case in Weld versions released before June 2015, but not in Weld versions released after June 2015 (2.2.14/2.3.0.B1/3.0.0.A9) nor in OpenWebBeans due to an oversight in CDI spec. In those Weld versions and in all OWB versions it is only with the first character lowercased #{fOOBean}.

  • If you have explicitly specified a managed bean name foo like below,

      @Named("foo")
      public class FooBean {}
    

    or equivalently with @ManagedBean(name="foo") or @Component("foo"), then it will only be available by #{foo} and thus not by #{fooBean}.


1c. Where's the backing bean class?

Third step would be doublechecking if the backing bean class is at the right place in the built and deployed WAR file. Make sure that you've properly performed a full clean, rebuild, redeploy and restart of the project and server in case you was actually busy writing code and impatiently pressing F5 in the browser. If still in vain, let the build system produce a WAR file, which you then extract and inspect with a ZIP tool. The compiled .class file of the backing bean class must reside in its package structure in /WEB-INF/classes. Or, when it's packaged as part of a JAR module, the JAR containing the compiled .class file must reside in /WEB-INF/lib and thus not e.g. EAR's /lib or elsewhere.

If you're using Eclipse, make sure that the backing bean class is in src and thus not WebContent, and make sure that Project > Build Automatically is enabled. If you're using Maven, make sure that the backing bean class is in src/main/java and thus not in src/main/resources or src/main/webapp.

If you're packaging the web application as part of an EAR with EJB+WAR(s), then you need to make sure that the backing bean classes are in WAR module and thus not in EAR module nor EJB module. The business tier (EJB) must be free of any web tier (WAR) related artifacts, so that the business tier is reusable across multiple different web tiers (JSF, JAX-RS, JSP/Servlet, etc).


2. Target Unreachable, 'entity' returned null

This boils down to that the nested property entity as in #{bean.entity.property} returned null. This usually only exposes when JSF needs to set the value for property via an input component like below, while the #{bean.entity} actually returned null.

<h:inputText value="#{bean.entity.property}" />

You need to make sure that you have prepared the model entity beforehand in a @PostConstruct, or <f:viewAction> method, or perhaps an add() action method in case you're working with CRUD lists and/or dialogs on same view.

@Named
@ViewScoped
public class Bean {

    private Entity entity; // +getter (setter is not necessary).

    @Inject
    private EntityService entityService;

    @PostConstruct
    public void init() {
        // In case you're updating an existing entity.
        entity = entityService.getById(entityId);

        // Or in case you want to create a new entity.
        entity = new Entity();
    }

    // ...
}

As to the importance of @PostConstruct; doing this in a regular constructor would fail in case you're using a bean management framework which uses proxies, such as CDI. Always use @PostConstruct to hook on managed bean instance initialization (and use @PreDestroy to hook on managed bean instance destruction). Additionally, in a constructor you wouldn't have access to any injected dependencies yet, see also NullPointerException while trying to access @Inject bean in constructor.

In case the entityId is supplied via <f:viewParam>, you'd need to use <f:viewAction> instead of @PostConstruct. See also When to use f:viewAction / preRenderView versus PostConstruct?

You also need to make sure that you preserve the non-null model during postbacks in case you're creating it only in an add() action method. Easiest would be to put the bean in the view scope. See also How to choose the right bean scope?


3. Target Unreachable, 'null' returned null

This has actually the same cause as #2, only the (older) EL implementation being used is somewhat buggy in preserving the property name to display in the exception message, which ultimately incorrectly exposed as 'null'. This only makes debugging and fixing a bit harder when you've quite some nested properties like so #{bean.entity.subentity.subsubentity.property}.

The solution is still the same: make sure that the nested entity in question is not null, in all levels.


4. Target Unreachable, ''0'' returned null

This has also the same cause as #2, only the (older) EL implementation being used is buggy in formulating the exception message. This exposes only when you use the brace notation [] in EL as in #{bean.collection[index]} where the #{bean.collection} itself is non-null, but the item at the specified index doesn't exist. Such a message must then be interpreted as:

Target Unreachable, 'collection[0]' returned null

The solution is also the same as #2: make sure that the collection item is available.


5. Target Unreachable, 'BracketSuffix' returned null

This has actually the same cause as #4, only the (older) EL implementation being used is somewhat buggy in preserving the iteration index to display in the exception message, which ultimately incorrectly exposed as 'BracketSuffix' which is really the character ]. This only makes debugging and fixing a bit harder when you've multiple items in the collection.


Other possible causes of javax.el.PropertyNotFoundException:

How to echo in PHP, HTML tags

Using the first mechanism given there will do it.

<?php
  ...
?>
<div>
 <h3><a href="#">First</a></h3>
 <div>Lorem ipsum dolor sit amet.</div>
</div>
<div>
<?php
  ...
?>

Interfaces vs. abstract classes

The advantages of an abstract class are:

  • Ability to specify default implementations of methods
  • Added invariant checking to functions
  • Have slightly more control in how the "interface" methods are called
  • Ability to provide behavior related or unrelated to the interface for "free"

Interfaces are merely data passing contracts and do not have these features. However, they are typically more flexible as a type can only be derived from one class, but can implement any number of interfaces.

iOS 7 App Icons, Launch images And Naming Convention While Keeping iOS 6 Icons

Absolutely Asset Catalog is you answer, it removes the need to follow naming conventions when you are adding or updating your app icons.

Below are the steps to Migrating an App Icon Set or Launch Image Set From Apple:

1- In the project navigator, select your target.

2- Select the General pane, and scroll to the App Icons section.

enter image description here

3- Specify an image in the App Icon table by clicking the folder icon on the right side of the image row and selecting the image file in the dialog that appears.

enter image description here

4-Migrate the images in the App Icon table to an asset catalog by clicking the Use Asset Catalog button, selecting an asset catalog from the popup menu, and clicking the Migrate button.

enter image description here

Alternatively, you can create an empty app icon set by choosing Editor > New App Icon, and add images to the set by dragging them from the Finder or by choosing Editor > Import.

Unique device identification

You can use the fingerprintJS2 library, it helps a lot with calculating a browser fingerprint.

By the way, on Panopticlick you can see how unique this usually is.

How to generate a random int in C?

Note: Don't use rand() for security. If you need a cryptographically secure number, see this answer instead.

#include <time.h>
#include <stdlib.h>

srand(time(NULL));   // Initialization, should only be called once.
int r = rand();      // Returns a pseudo-random integer between 0 and RAND_MAX.

On Linux, you might prefer to use random and srandom.

show validation error messages on submit in angularjs

There are two simple & elegant ways to do it.

Pure CSS:

After first form submission, despite the form validity, Angular will add a ng-submitted class to all form elements inside the form just submitted.

We can use .ng-submitted to controller our element via CSS.

if you want to display an error text only when user have submitted e.g.

.error { display: none }
.ng-submitted .error {
     display: block;
}

Using a value from Scope:
After first form submission, despite the form validity, Angular will set [your form name].$submitted to true. Thus, we can use that value to control elements.

<div ng-show="yourFormName.$submitted">error message</div>
<form name="yourFormName"></form>

How to set the text color of TextView in code?

In order to set color of a TextView, TextView.setTextColor(R.color.YOURCOLOR) is not enough!

It has to be used like this –

TextView myText = (TextView) findViewById(R.id.YoutTextViewID);

myText.setTextColor(getResources().getColor(R.color.YOURCOLOR);

OR

myText.setTextColor(Color.parseColor("#54D66A"));

Effects of the extern keyword on C functions

The reason it has no effect is because at the link-time the linker tries to resolve the extern definition (in your case extern int f()). It doesn't matter if it finds it in the same file or a different file, as long as it is found.

Hope this answers your question.

Send data from javascript to a mysql database

JavaScript, as defined in your question, can't directly work with MySql. This is because it isn't running on the same computer.

JavaScript runs on the client side (in the browser), and databases usually exist on the server side. You'll probably need to use an intermediate server-side language (like PHP, Java, .Net, or a server-side JavaScript stack like Node.js) to do the query.

Here's a tutorial on how to write some code that would bind PHP, JavaScript, and MySql together, with code running both in the browser, and on a server:

http://www.w3schools.com/php/php_ajax_database.asp

And here's the code from that page. It doesn't exactly match your scenario (it does a query, and doesn't store data in the DB), but it might help you start to understand the types of interactions you'll need in order to make this work.

In particular, pay attention to these bits of code from that article.

Bits of Javascript:

xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();

Bits of PHP code:

mysql_select_db("ajax_demo", $con);
$result = mysql_query($sql);
// ...
$row = mysql_fetch_array($result)
mysql_close($con);

Also, after you get a handle on how this sort of code works, I suggest you use the jQuery JavaScript library to do your AJAX calls. It is much cleaner and easier to deal with than the built-in AJAX support, and you won't have to write browser-specific code, as jQuery has cross-browser support built in. Here's the page for the jQuery AJAX API documentation.

The code from the article

HTML/Javascript code:

<html>
<head>
<script type="text/javascript">
function showUser(str)
{
if (str=="")
  {
  document.getElementById("txtHint").innerHTML="";
  return;
  } 
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>

<form>
<select name="users" onchange="showUser(this.value)">
<option value="">Select a person:</option>
<option value="1">Peter Griffin</option>
<option value="2">Lois Griffin</option>
<option value="3">Glenn Quagmire</option>
<option value="4">Joseph Swanson</option>
</select>
</form>
<br />
<div id="txtHint"><b>Person info will be listed here.</b></div>

</body>
</html>

PHP code:

<?php
$q=$_GET["q"];

$con = mysql_connect('localhost', 'peter', 'abc123');
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("ajax_demo", $con);

$sql="SELECT * FROM user WHERE id = '".$q."'";

$result = mysql_query($sql);

echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
<th>Hometown</th>
<th>Job</th>
</tr>";

while($row = mysql_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['FirstName'] . "</td>";
  echo "<td>" . $row['LastName'] . "</td>";
  echo "<td>" . $row['Age'] . "</td>";
  echo "<td>" . $row['Hometown'] . "</td>";
  echo "<td>" . $row['Job'] . "</td>";
  echo "</tr>";
  }
echo "</table>";

mysql_close($con);
?>

How to compile python script to binary executable

Or use PyInstaller as an alternative to py2exe. Here is a good starting point. PyInstaller also lets you create executables for linux and mac...

Here is how one could fairly easily use PyInstaller to solve the issue at hand:

pyinstaller oldlogs.py

From the tool's documentation:

PyInstaller analyzes myscript.py and:

  • Writes myscript.spec in the same folder as the script.
  • Creates a folder build in the same folder as the script if it does not exist.
  • Writes some log files and working files in the build folder.
  • Creates a folder dist in the same folder as the script if it does not exist.
  • Writes the myscript executable folder in the dist folder.

In the dist folder you find the bundled app you distribute to your users.

navigator.geolocation.getCurrentPosition sometimes works sometimes doesn't

For anyone working on an iPhone app...

If your code is running in a UIWebView on iOS 9+, then you must set NSLocationWhenInUseUsageDescription within your app's plist.

If you don't set it then getCurrentPosition will never call back and the user will never be prompted.

Colors in JavaScript console

This library is fantastic:

https://github.com/adamschwartz/log

Use Markdown for log messages.

When do items in HTML5 local storage expire?

Brynner Ferreira, has brought a good point: storing a sibling key where expiration info resides. This way, if you have a large amount of keys, or if your values are large Json objects, you don't need to parse them to access the timestamp.

here follows an improved version:

 /*  removeStorage: removes a key from localStorage and its sibling expiracy key
    params:
        key <string>     : localStorage key to remove
    returns:
        <boolean> : telling if operation succeeded
 */
 function removeStorage(name) {
    try {
        localStorage.removeItem(name);
        localStorage.removeItem(name + '_expiresIn');
    } catch(e) {
        console.log('removeStorage: Error removing key ['+ key + '] from localStorage: ' + JSON.stringify(e) );
        return false;
    }
    return true;
}
/*  getStorage: retrieves a key from localStorage previously set with setStorage().
    params:
        key <string> : localStorage key
    returns:
        <string> : value of localStorage key
        null : in case of expired key or failure
 */
function getStorage(key) {

    var now = Date.now();  //epoch time, lets deal only with integer
    // set expiration for storage
    var expiresIn = localStorage.getItem(key+'_expiresIn');
    if (expiresIn===undefined || expiresIn===null) { expiresIn = 0; }

    if (expiresIn < now) {// Expired
        removeStorage(key);
        return null;
    } else {
        try {
            var value = localStorage.getItem(key);
            return value;
        } catch(e) {
            console.log('getStorage: Error reading key ['+ key + '] from localStorage: ' + JSON.stringify(e) );
            return null;
        }
    }
}
/*  setStorage: writes a key into localStorage setting a expire time
    params:
        key <string>     : localStorage key
        value <string>   : localStorage value
        expires <number> : number of seconds from now to expire the key
    returns:
        <boolean> : telling if operation succeeded
 */
function setStorage(key, value, expires) {

    if (expires===undefined || expires===null) {
        expires = (24*60*60);  // default: seconds for 1 day
    } else {
        expires = Math.abs(expires); //make sure it's positive
    }

    var now = Date.now();  //millisecs since epoch time, lets deal only with integer
    var schedule = now + expires*1000; 
    try {
        localStorage.setItem(key, value);
        localStorage.setItem(key + '_expiresIn', schedule);
    } catch(e) {
        console.log('setStorage: Error setting key ['+ key + '] in localStorage: ' + JSON.stringify(e) );
        return false;
    }
    return true;
}

WordPress asking for my FTP credentials to install plugins

I changed the ownership of the wordpress folder to www-data recursively and restarted apache.

sudo chown -R www-data:www-data <folderpath>

It worked like a charm!

Java 8 method references: provide a Supplier capable of supplying a parameterized result

optionalUsers.orElseThrow(() -> new UsernameNotFoundException("Username not found"));

Data-frame Object has no Attribute

Check your DataFrame with data.columns

It should print something like this

Index([u'regiment', u'company',  u'name',u'postTestScore'], dtype='object')

Check for hidden white spaces..Then you can rename with

data = data.rename(columns={'Number ': 'Number'})

How to overwrite styling in Twitter Bootstrap

Came across this late, but I think it could use another answer.

If you're using sass, you can actually change the variables before you import bootstrap. http://twitter.github.com/bootstrap/customize.html#variables

Change any of them, such as:

$bodyBackground: red;
@import "bootstrap";

Alternatively if there isn't a variable available for what you want to change, you can override the styles or add your own.

Sass:

@import "bootstrap";

/* override anything manually, like rounded buttons */
.btn {
  border-radius: 0;
}

Also see this: Proper SCSS Asset Structure in Rails

How to recover just deleted rows in mysql?

For InnoDB tables, Percona has a recovery tool which may help. It is far from fail-safe or perfect, and how fast you stopped your MySQL server after the accidental deletes has a major impact. If you're quick enough, changes are you can recover quite a bit of data, but recovering all data is nigh impossible.

Of cours, proper daily backups, binlogs, and possibly a replication slave (which won't help for accidental deletes but does help in case of hardware failure) are the way to go, but this tool could enable you to save as much data as possible when you did not have those yet.

Is there a better way to compare dictionary values

>>> a = {'x': 1, 'y': 2}
>>> b = {'y': 2, 'x': 1}
>>> print a == b
True
>>> c = {'z': 1}
>>> print a == c
False
>>> 

Reverse a string without using reversed() or [::-1]?

reduce(lambda x, y : y + x, "hello world")

Laravel: Validation unique on update

If i understand what you want:

'email' => 'required|email|unique:users,email_address,'. $id .''

In model update method, for exemple, should receive the $id with parameter.

Sorry my bad english.

Django - filtering on foreign key properties

student_user = User.objects.get(id=user_id)
available_subjects = Subject.objects.exclude(subject_grade__student__user=student_user) # My ans
enrolled_subjects = SubjectGrade.objects.filter(student__user=student_user)
context.update({'available_subjects': available_subjects, 'student_user': student_user, 
                'request':request, 'enrolled_subjects': enrolled_subjects})

In my application above, i assume that once a student is enrolled, a subject SubjectGrade instance will be created that contains the subject enrolled and the student himself/herself.

Subject and Student User model is a Foreign Key to the SubjectGrade Model.

In "available_subjects", i excluded all the subjects that are already enrolled by the current student_user by checking all subjectgrade instance that has "student" attribute as the current student_user

PS. Apologies in Advance if you can't still understand because of my explanation. This is the best explanation i Can Provide. Thank you so much

Query for array elements inside JSON type

jsonb in Postgres 9.4+

You can use the same query as below, just with jsonb_array_elements().

But rather use the jsonb "contains" operator @> in combination with a matching GIN index on the expression data->'objects':

CREATE INDEX reports_data_gin_idx ON reports
USING gin ((data->'objects') jsonb_path_ops);

SELECT * FROM reports WHERE data->'objects' @> '[{"src":"foo.png"}]';

Since the key objects holds a JSON array, we need to match the structure in the search term and wrap the array element into square brackets, too. Drop the array brackets when searching a plain record.

More explanation and options:

json in Postgres 9.3+

Unnest the JSON array with the function json_array_elements() in a lateral join in the FROM clause and test for its elements:

SELECT data::text, obj
FROM   reports r, json_array_elements(r.data#>'{objects}') obj
WHERE  obj->>'src' = 'foo.png';

db<>fiddle here
Old sqlfiddle

The CTE (WITH query) just substitutes for a table reports.
Or, equivalent for just a single level of nesting:

SELECT *
FROM   reports r, json_array_elements(r.data->'objects') obj
WHERE  obj->>'src' = 'foo.png';

->>, -> and #> operators are explained in the manual.

Both queries use an implicit JOIN LATERAL.

Closely related:

What is the difference between signed and unsigned int

In practice, there are two differences:

  1. printing (eg with cout in C++ or printf in C): unsigned integer bit representation is interpreted as a nonnegative integer by print functions.
  2. ordering: the ordering depends on signed or unsigned specifications.

this code can identify the integer using ordering criterion:

char a = 0;
a--;
if (0 < a)
    printf("unsigned");
else
    printf("signed");

char is considered signed in some compilers and unsigned in other compilers. The code above determines which one is considered in a compiler, using the ordering criterion. If a is unsigned, after a--, it will be greater than 0, but if it is signed it will be less than zero. But in both cases, the bit representation of a is the same. That is, in both cases a-- does the same change to the bit representation.

getting the last item in a javascript object

Let obj be your object. Exec:

(_ => _[Object.keys(_).pop()])( obj )

How to download image using requests

Following code snippet downloads a file.

The file is saved with its filename as in specified url.

import requests

url = "http://example.com/image.jpg"
filename = url.split("/")[-1]
r = requests.get(url, timeout=0.5)

if r.status_code == 200:
    with open(filename, 'wb') as f:
        f.write(r.content)

d3.select("#element") not working when code above the html element

just add your <script src="./custom.js"></script> before </bod> tag. that is supply time to d3.select(#chart) detect your #chart element in html body

Html code as IFRAME source rather than a URL

You can do this with a data URL. This includes the entire document in a single string of HTML. For example, the following HTML:

<html><body>foo</body></html>

can be encoded as this:

data:text/html;charset=utf-8,%3Chtml%3E%3Cbody%3Efoo%3C/body%3E%3C/html%3E

and then set as the src attribute of the iframe. Example.


Edit: The other alternative is to do this with Javascript. This is almost certainly the technique I'd choose. You can't guarantee how long a data URL the browser will accept. The Javascript technique would look something like this:

var iframe = document.getElementById('foo'),
    iframedoc = iframe.contentDocument || iframe.contentWindow.document;

iframedoc.body.innerHTML = 'Hello world';

Example


Edit 2 (December 2017): use the Html5's srcdoc attribute, just like in Saurabh Chandra Patel's answer, who now should be the accepted answer! If you can detect IE/Edge efficiently, a tip is to use srcdoc-polyfill library only for them and the "pure" srcdoc attribute in all non-IE/Edge browsers (check caniuse.com to be sure).

<iframe srcdoc="<html><body>Hello, <b>world</b>.</body></html>"></iframe>

Javascript loop through object array?

Iterations

Method 1: forEach method

messages.forEach(function(message) {
   console.log(message);
}

Method 2: for..of method

for(let message of messages){
   console.log(message);
}

Note: This method might not work with objects, such as:

let obj = { a: 'foo', b: { c: 'bar', d: 'daz' }, e: 'qux' }

Method 2: for..in method

for(let key in messages){
       console.log(messages[key]);
 }

Writing file to web server - ASP.NET

There are methods like WriteAllText in the File class for common operations on files.

Use the MapPath method to get the physical path for a file in your web application.

File.WriteAllText(Server.MapPath("~/data.txt"), TextBox1.Text);

How to list installed packages from a given repo using yum

On newer versions of yum, this information is stored in the "yumdb" when the package is installed. This is the only 100% accurate way to get the information, and you can use:

yumdb search from_repo repoid

(or repoquery and grep -- don't grep yum output). However the command "find-repos-of-install" was part of yum-utils for a while which did the best guess without that information:

http://james.fedorapeople.org/yum/commands/find-repos-of-install.py

As floyd said, a lot of repos. include a unique "dist" tag in their release, and you can look for that ... however from what you said, I guess that isn't the case for you?

Creation timestamp and last update timestamp with Hibernate and MySQL

You can also use an interceptor to set the values

Create an interface called TimeStamped which your entities implement

public interface TimeStamped {
    public Date getCreatedDate();
    public void setCreatedDate(Date createdDate);
    public Date getLastUpdated();
    public void setLastUpdated(Date lastUpdatedDate);
}

Define the interceptor

public class TimeStampInterceptor extends EmptyInterceptor {

    public boolean onFlushDirty(Object entity, Serializable id, Object[] currentState, 
            Object[] previousState, String[] propertyNames, Type[] types) {
        if (entity instanceof TimeStamped) {
            int indexOf = ArrayUtils.indexOf(propertyNames, "lastUpdated");
            currentState[indexOf] = new Date();
            return true;
        }
        return false;
    }

    public boolean onSave(Object entity, Serializable id, Object[] state, 
            String[] propertyNames, Type[] types) {
            if (entity instanceof TimeStamped) {
                int indexOf = ArrayUtils.indexOf(propertyNames, "createdDate");
                state[indexOf] = new Date();
                return true;
            }
            return false;
    }
}

And register it with the session factory

Should I use PATCH or PUT in my REST API?

I would generally prefer something a bit simpler, like activate/deactivate sub-resource (linked by a Link header with rel=service).

POST /groups/api/v1/groups/{group id}/activate

or

POST /groups/api/v1/groups/{group id}/deactivate

For the consumer, this interface is dead-simple, and it follows REST principles without bogging you down in conceptualizing "activations" as individual resources.

PHP: HTTP or HTTPS?

$protocol = strtolower(substr($_SERVER["SERVER_PROTOCOL"],0,5))=='https'?'https':'http';

$protocol = isset($_SERVER["HTTPS"]) ? 'https' : 'http';

These should both work

How to delete columns that contain ONLY NAs?

Another option with Filter

Filter(function(x) !all(is.na(x)), df)

NOTE: Data from @Simon O'Hanlon's post.

jQuery Force set src attribute for iframe

While generating the links set the target to the iframes name property and you probably wont have to deal with jquery at all.

<a href="inventory.aspx" target="contentframe"  title="Title Inventory">
<iframe id="iframe1" name="contentframe"  ></iframe>

Java 8 - Difference between Optional.flatMap and Optional.map

Note:- below is the illustration of map and flatmap function, otherwise Optional is primarily designed to be used as a return type only.

As you already may know Optional is a kind of container which may or may not contain a single object, so it can be used wherever you anticipate a null value(You may never see NPE if use Optional properly). For example if you have a method which expects a person object which may be nullable you may want to write the method something like this:

void doSome(Optional<Person> person){
  /*and here you want to retrieve some property phone out of person
    you may write something like this:
  */
  Optional<String> phone = person.map((p)->p.getPhone());
  phone.ifPresent((ph)->dial(ph));
}
class Person{
  private String phone;
  //setter, getters
}

Here you have returned a String type which is automatically wrapped in an Optional type.

If person class looked like this, i.e. phone is also Optional

class Person{
  private Optional<String> phone;
  //setter,getter
}

In this case invoking map function will wrap the returned value in Optional and yield something like:

Optional<Optional<String>> 
//And you may want Optional<String> instead, here comes flatMap

void doSome(Optional<Person> person){
  Optional<String> phone = person.flatMap((p)->p.getPhone());
  phone.ifPresent((ph)->dial(ph));
}

PS; Never call get method (if you need to) on an Optional without checking it with isPresent() unless you can't live without NullPointerExceptions.

Auto height div with overflow and scroll when needed

I'm surprised no one's mentioned calc() yet.

I wasn't able to make-out your specific case from your fiddles, but I understand your problem: you want a height: 100% container that can still use overflow-y: auto.

This doesn't work out of the box because overflow requires some hard-coded size constraint to know when it ought to start handling overflow. So, if you went with height: 100px, it'd work as expected.

The good news is that calc() can help, but it's not as simple as height: 100%.

calc() lets you combine arbitrary units of measure.

So, for the situation you describe in the picture you include: picture of desired state

Since all the elements above and below the pink div are of a known height (let's say, 200px in total height), you can use calc to determine the height of ole pinky:

height: calc(100vh - 200px);

or, 'height is 100% of the view height minus 200px.'

Then, overflow-y: auto should work like a charm.