Programs & Examples On #Language history

How do I install Maven with Yum?

Not just mvn, for any util, you can find out yourself by giving yum whatprovides {command_name}

Algorithm to calculate the number of divisors of a given number

@Kendall

I tested your code and made some improvements, now it is even faster. I also tested with @???? ???????? code, this is also faster than his code.

long long int FindDivisors(long long int n) {
  long long int count = 0;
  long long int i, m = (long long int)sqrt(n);
  for(i = 1;i <= m;i++) {
    if(n % i == 0)
      count += 2;
  }
  if(n / m == m && n % m == 0)
    count--;
  return count;
}

How to know what the 'errno' means?

I use the following script:

#!/usr/bin/python

import errno
import os
import sys

toname = dict((str(getattr(errno, x)), x) 
              for x in dir(errno) 
              if x.startswith("E"))
tocode = dict((x, getattr(errno, x)) 
              for x in dir(errno) 
              if x.startswith("E"))

for arg in sys.argv[1:]:
    if arg in tocode:
        print arg, tocode[arg], os.strerror(tocode[arg])
    elif arg in toname:
        print toname[arg], arg, os.strerror(int(arg))
    else:
        print "Unknown:", arg

Insertion sort vs Bubble Sort Algorithms

Number of swap in each iteration

  • Insertion-sort does at most 1 swap in each iteration.
  • Bubble-sort does 0 to n swaps in each iteration.

Accessing and changing sorted part

  • Insertion-sort accesses(and changes when needed) the sorted part to find the correct position of a number in consideration.
  • When optimized, Bubble-sort does not access what is already sorted.

Online or not

  • Insertion-sort is online. That means Insertion-sort takes one input at a time before it puts in appropriate position. It does not have to compare only adjacent-inputs.
  • Bubble-sort is not-online. It does not operate one input at a time. It handles a group of inputs(if not all) in each iteration. Bubble-sort only compare and swap adjacent-inputs in each iteration.

Get screen width and height in Android

This set of utilities to work with the Size abstraction in Android.

It contains a class SizeFromDisplay.java You can use it like this:

ISize size = new SizeFromDisplay(getWindowManager().getDefaultDisplay());
size.width();
size.hight();

How to get the 'height' of the screen using jquery

use with responsive website (view in mobile or ipad)

jQuery(window).height();   // return height of browser viewport
jQuery(window).width();    // return width of browser viewport

rarely use

jQuery(document).height(); // return height of HTML document
jQuery(document).width();  // return width of HTML document

How can I implement the Iterable interface?

First off:

public class ProfileCollection implements Iterable<Profile> {

Second:

return m_Profiles.get(m_ActiveProfile);

VB.Net Properties - Public Get, Private Set

    Public Property Name() As String
        Get
            Return _name
        End Get
        Private Set(ByVal value As String)
            _name = value
        End Set
   End Property

How to set 24-hours format for date on java?

tl;dr

The modern approach uses java.time classes.

Instant.now()                                        // Capture current moment in UTC.
       .truncatedTo( ChronoUnit.SECONDS )            // Lop off any fractional second.
       .plus( 8 , ChronoUnit.HOURS )                 // Add eight hours.
       .atZone( ZoneId.of( "America/Montreal" ) )    // Adjust from UTC to the wall-clock time used by the people of a certain region (a time zone). Returns a `ZonedDateTime` object.
       .format(                                      // Generate a `String` object representing textually the value of the `ZonedDateTime` object.
           DateTimeFormatter.ofPattern( "dd/MM/uuuu HH:mm:ss" )
                            .withLocale( Locale.US ) // Specify a `Locale` to determine the human language and cultural norms used in localizing the text being generated. 
       )                                             // Returns a `String` object.

23/01/2017 15:34:56

java.time

FYI, the old Calendar and Date classes are now legacy. Supplanted by the java.time classes. Much of java.time is back-ported to Java 6, Java 7, and Android (see below).

Instant

Capture the current moment in UTC with the Instant class.

Instant instantNow = Instant.now();

instant.toString(): 2017-01-23T12:34:56.789Z

If you want only whole seconds, without any fraction of a second, truncate.

Instant instant = instantNow.truncatedTo( ChronoUnit.SECONDS );

instant.toString(): 2017-01-23T12:34:56Z

Math

The Instant class can do math, adding an amount of time. Specify the amount of time to add by the ChronoUnit enum, an implementation of TemporalUnit.

instant = instant.plus( 8 , ChronoUnit.HOURS );

instant.toString(): 2017-01-23T20:34:56Z

ZonedDateTime

To see that same moment through the lens of a particular region’s wall-clock time, apply a ZoneId to get a ZonedDateTime.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = instant.atZone( z );

zdt.toString(): 2017-01-23T15:34:56-05:00[America/Montreal]

Generate string

You can generate a String in your desired format by specifying a formatting pattern in a DateTimeFormatter object.

Note that case matters in the letters of your formatting pattern. The Question’s code had hh which is for 12-hour time while uppercase HH is 24-hour time (0-23) in both java.time.DateTimeFormatter as well as the legacy java.text.SimpleDateFormat.

The formatting codes in java.time are similar to those in the legacy SimpleDateFormat but not exactly the same. Carefully study the class doc. Here, HH happens to work identically.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd/MM/uuuu HH:mm:ss" ).withLocale( Locale.US );
String output = zdt.format( f );

Automatic localization

Rather than hard-coding a formatting pattern, consider letting java.time fully localize the generation of the String text by calling DateTimeFormatter.ofLocalizedDateTime.

And, by the way, be aware that time zone and Locale have nothing to do with one another; orthogonal issues. One is about content, the meaning (the wall-clock time). The other is about presentation, determining the human language and cultural norms used in presenting that meaning to the user.

Instant instant = Instant.parse( "2017-01-23T12:34:56Z" );
ZoneId z = ZoneId.of( "Pacific/Auckland" );  // Notice that time zone is unrelated to the `Locale` used in localizing.
ZonedDateTime zdt = instant.atZone( z );

DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.FULL )
                                       .withLocale( Locale.CANADA_FRENCH );  // The locale determines human language and cultural norms used in generating the text representing this date-time object.
String output = zdt.format( f );

instant.toString(): 2017-01-23T12:34:56Z

zdt.toString(): 2017-01-24T01:34:56+13:00[Pacific/Auckland]

output: mardi 24 janvier 2017 à 01:34:56 heure avancée de la Nouvelle-Zélande


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?


Joda-Time

Update: The Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes.

Joda-Time makes this kind of work much easier.

// © 2013 Basil Bourque. This source code may be used freely forever by anyone taking full responsibility for doing so.
// import org.joda.time.*;
// import org.joda.time.format.*;

DateTime later = DateTime.now().plusHours( 8 );
DateTimeFormatter formatter = DateTimeFormat.forPattern( "dd/MM/yyyy HH:mm:ss" );
String laterAsText = formatter.print( later );

System.out.println( "laterAsText: " + laterAsText );

When run…

laterAsText: 19/12/2013 02:50:18

Beware that this syntax uses default time zone. A better practice is to use an explicit DateTimeZone instance.

How to save public key from a certificate in .pem format

if it is a RSA key

openssl rsa  -pubout -in my_rsa_key.pem

if you need it in a format for openssh , please see Use RSA private key to generate public key?

Note that public key is generated from the private key and ssh uses the identity file (private key file) to generate and send public key to server and un-encrypt the encrypted token from the server via the private key in identity file.

HTML5 video won't play in Chrome only

Have you tried by setting the MIME type of your .m4v to "video/m4v" or "video/x-m4v" ?

Browsers might use the canPlayType method internally to check if a <source> is candidate to playback.

In Chrome, I have these results:

document.createElement("video").canPlayType("video/mp4"); // "maybe"
document.createElement("video").canPlayType("video/m4v"); // ""
document.createElement("video").canPlayType("video/x-m4v"); // "maybe"

Modify a Column's Type in sqlite3

It is possible by recreating table.Its work for me please follow following step:

  1. create temporary table using as select * from your table
  2. drop your table, create your table using modify column type
  3. now insert records from temp table to your newly created table
  4. drop temporary table

do all above steps in worker thread to reduce load on uithread

JNI converting jstring to char *

Thanks Jason Rogers's answer first.

In Android && cpp should be this:

const char *nativeString = env->GetStringUTFChars(javaString, nullptr);

// use your string

env->ReleaseStringUTFChars(javaString, nativeString);

Can fix this errors:

1.error: base operand of '->' has non-pointer type 'JNIEnv {aka _JNIEnv}'

2.error: no matching function for call to '_JNIEnv::GetStringUTFChars(JNIEnv*&, _jstring*&, bool)'

3.error: no matching function for call to '_JNIEnv::ReleaseStringUTFChars(JNIEnv*&, _jstring*&, char const*&)'

4.add "env->DeleteLocalRef(nativeString);" at end.

How to update the value stored in Dictionary in C#?

Here is a way to update by an index much like foo[x] = 9 where x is a key and 9 is the value

var views = new Dictionary<string, bool>();

foreach (var g in grantMasks)
{
    string m = g.ToString();
    for (int i = 0; i <= m.Length; i++)
    {
        views[views.ElementAt(i).Key] = m[i].Equals('1') ? true : false;
    }
}

C# "must declare a body because it is not marked abstract, extern, or partial"

You can just use the keywork value to accomplish this.

public int Hour {
    get{
        // Do some logic if you want
        //return some custom stuff based on logic

        // or just return the value
        return value;
    }; set { 
        // Do some logic stuff 
        if(value < MINVALUE){
            this.Hour = 0;
        } else {
            // Or just set the value
            this.Hour = value;
        }
    }
}

SQL Server - An expression of non-boolean type specified in a context where a condition is expected, near 'RETURN'

YOu can also rewrite it like this

FROM Resource r WHERE r.ResourceNo IN
        ( 
            SELECT m.ResourceNo FROM JobMember m
            JOIN Job j ON j.JobNo = m.JobNo
            WHERE j.ProjectManagerNo = @UserResourceNo 
            OR
            j.AlternateProjectManagerNo = @UserResourceNo

            Union All

            SELECT m.ResourceNo FROM JobMember m
            JOIN JobTask t ON t.JobTaskNo = m.JobTaskNo
            WHERE t.TaskManagerNo = @UserResourceNo
            OR
            t.AlternateTaskManagerNo = @UserResourceNo

        )

Also a return table is expected in your RETURN statement

Show Image View from file path?

You can also use:



    File imgFile = new  File(“filepath”);
    if(imgFile.exists())
    {
        ImageView myImage = new ImageView(this);
        myImage.setImageURI(Uri.fromFile(imgFile));

    }

This does the bitmap decoding implicit for you.

Anybody knows any knowledge base open source?

In addition to MediaWiki that was mentioned by Kenny, you might also look at MoinMoin.

Choosing between MediaWiki and MoinMoin can be a bit tough. Here are some points to consider:

MediaWiki

Pros:

  • Made for wikipedia, thus is very mature and scalable.
  • Fairly easy to set up.

    Cons:

  • Made soley for wikipedia. Thus it can be a bit of a pain to customize how you like it.

MoinMoin

Pros:

  • Very mature software.
  • Huge amount of plugins and third party modules available.

    Cons:

  • Can be a pain to install.

There are a huge amount of other wikis available, but those are the main two I would consider.

What is the difference between user variables and system variables?

System environment variables are globally accessed by all users.
User environment variables are specific only to the currently logged-in user.

How to use sha256 in php5.3.0

The first thing is to make a comparison of functions of SHA and opt for the safest algorithm that supports your programming language (PHP).

Then you can chew the official documentation to implement the hash() function that receives as argument the hashing algorithm you have chosen and the raw password.

sha256 => 64 bits sha384 => 96 bits sha512 => 128 bits

The more secure the hashing algorithm is, the higher the cost in terms of hashing and time to recover the original value from the server side.

$hashedPassword = hash('sha256', $password);

How can I shuffle the lines of a text file on the Unix command line or in a shell script?

I use a tiny perl script, which I call "unsort":

#!/usr/bin/perl
use List::Util 'shuffle';
@list = <STDIN>;
print shuffle(@list);

I've also got a NULL-delimited version, called "unsort0" ... handy for use with find -print0 and so on.

PS: Voted up 'shuf' too, I had no idea that was there in coreutils these days ... the above may still be useful if your systems doesn't have 'shuf'.

How do I find a stored procedure containing <text>?

SELECT * FROM sys.procedures WHERE Name LIKE '%CompanySpecialisation%'

This is what I have written in SQL 2012 to select all stored procedures where name like "CompanySpecialisation"

jQuery's .click - pass parameters to user function

You need to use an anonymous function like this:

$('.leadtoscore').click(function() {
  add_event('shot')
});

You can call it like you have in the example, just a function name without parameters, like this:

$('.leadtoscore').click(add_event);

But the add_event method won't get 'shot' as it's parameter, but rather whatever click passes to it's callback, which is the event object itself...so it's not applicable in this case, but works for many others. If you need to pass parameters, use an anonymous function...or, there's one other option, use .bind() and pass data, like this:

$('.leadtoscore').bind('click', { param: 'shot' }, add_event);

And access it in add_event, like this:

function add_event(event) {
  //event.data.param == "shot", use as needed
}

Using Camera in the Android emulator

Does not seem like it, but android recognises a webcam as a device. Every time I run the emulator my webcam's active light comes on.

java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication Maven

Adding below to pom.xml solved my problem

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

Update row with data from another row in the same table

Here's my go:

UPDATE test as t1 
    INNER JOIN test as t2 ON 
        t1.NAME = t2.NAME AND 
        t2.value IS NOT NULL 
SET t1.VALUE = t2.VALUE;

EDIT: Removed superfluous t1.id != t2.id condition.

Check if a process is running or not on Windows with Python

This works nicely

def running():
    n=0# number of instances of the program running 
    prog=[line.split() for line in subprocess.check_output("tasklist").splitlines()]
    [prog.pop(e) for e in [0,1,2]] #useless 
    for task in prog:
        if task[0]=="itunes.exe":
            n=n+1
    if n>0:
        return True
    else:
        return False

Image resolution for new iPhone 6 and 6+, @3x support added?

UPDATE:

New link for the icons image size by apple.

https://developer.apple.com/ios/human-interface-guidelines/graphics/image-size-and-resolution/

enter image description here


Yes it's True here it is Apple provide Official documentation regarding icon's or image size

enter image description here

you have to set images for iPhone6 and iPhone6+

For iPhone 6:

750 x 1334 (@2x) for portrait

1334 x 750 (@2x) for landscape

For iPhone 6 Plus:

1242 x 2208 (@3x) for portrait

2208 x 1242 (@3x) for landscape

For more info regarding Images and it's resolution this is best ever helpful post

For setting images size for controls you can set 1x @2x and @3x like following:

enter image description here

pop/remove items out of a python tuple

ok I figured out a crude way of doing it.

I store the "n" value in the for loop when condition is satisfied in a list (lets call it delList) then do the following:

    for ii in sorted(delList, reverse=True):
    tupleX.pop(ii)

Any other suggestions are welcome too.

javascript - match string against the array of regular expressions

let expressions = [ '/something/', '/something_else/', '/and_something_else/'];

let str = 'else';

here will be the check for following expressions:

if( expressions.find(expression => expression.includes(str) ) ) {

}

using Array .find() method to traverse array and .include to check substring

Defining arrays in Google Scripts

I think that maybe it is because you are declaring a variable that you already declared:

var Name = new Array(6);
//...
var Name[0] = Name_cell.getValue();  //  <-- Here's the issue: 'var'

I think this should be like this:

var Name = new Array(6);
//...
Name[0] = Name_cell.getValue();

Tell me if it works! ;)

How can I fix the Microsoft Visual Studio error: "package did not load correctly"?

Solution for Visual Studio 2017:

Step 1: open Visual Studio cmd in administrator mode (see start menu item: Developer Command Prompt for VS 2017 - Be sure to use: Run as administrator)

Step 2: change directory to the folder where Visual Studio 2017 is installed, for example:

cd C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise

(You can copy/paste this command to your cmd prompt. For Visual Studio Professional, the folder will be called "Professional" instead of "Enterprise", etc.)

Step 3: copy/paste the below command

gacutil -if Common7\IDE\PublicAssemblies\Microsoft.VisualStudio.Shell.Interop.8.0.dll

Hit Enter...

It will resolve the issue...

Otherwise, you can also add the following to the GAC as above:

Microsoft.VisualStudio.Shell.Interop.9.0.dll

Microsoft.VisualStudio.Shell.Interop.10.0.dll

Microsoft.VisualStudio.Shell.Interop.11.0.dll

Understanding generators in Python

I put up this piece of code which explains 3 key concepts about generators:

def numbers():
    for i in range(10):
            yield i

gen = numbers() #this line only returns a generator object, it does not run the code defined inside numbers

for i in gen: #we iterate over the generator and the values are printed
    print(i)

#the generator is now empty

for i in gen: #so this for block does not print anything
    print(i)

Android Studio - Unable to find valid certification path to requested target

Try to update your Android Studio, now is version 1.0.2

jQuery ajax post file field

This should help. How can I upload files asynchronously?

As the post suggest I recommend a plugin located here http://malsup.com/jquery/form/#code-samples

Foreach in a Foreach in MVC View

Assuming your controller's action method is something like this:

public ActionResult AllCategories(int id = 0)
{
    return View(db.Categories.Include(p => p.Products).ToList());
}

Modify your models to be something like this:

public class Product
{
    [Key]
    public int ID { get; set; }
    public int CategoryID { get; set; }
    //new code
    public virtual Category Category { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string Path { get; set; }

    //remove code below
    //public virtual ICollection<Category> Categories { get; set; }
}

public class Category
{
    [Key]
    public int CategoryID { get; set; }
    public string Name { get; set; }
    //new code
    public virtual ICollection<Product> Products{ get; set; }
}

Then your since now the controller takes in a Category as Model (instead of a Product):

foreach (var category in Model)
{
    <h3><u>@category.Name</u></h3>
    <div>
        <ul>    
            @foreach (var product in Model.Products)
            {
                // cut for brevity, need to add back more code from original
                <li>@product.Title</li>
            }
        </ul>
    </div>
}

UPDATED: Add ToList() to the controller return statement.

Change the image source on rollover using jQuery

A generic solution that doesn't limit you to "this image" and "that image" only may be to add the 'onmouseover' and 'onmouseout' tags to the HTML code itself.

HTML

<img src="img1.jpg" onmouseover="swap('img2.jpg')" onmouseout="swap('img1.jpg')" />

JavaScript

function swap(newImg){
  this.src = newImg;
}

Depending on your setup, maybe something like this would work better (and requires less HTML modification).

HTML

<img src="img1.jpg" id="ref1" />
<img src="img3.jpg" id="ref2" />
<img src="img5.jpg" id="ref3" />

JavaScript / jQuery

// Declare Arrays
  imgList = new Array();
  imgList["ref1"] = new Array();
  imgList["ref2"] = new Array();
  imgList["ref3"] = new Array();

//Set values for each mouse state
  imgList["ref1"]["out"] = "img1.jpg";
  imgList["ref1"]["over"] = "img2.jpg";
  imgList["ref2"]["out"] = "img3.jpg";
  imgList["ref2"]["over"] = "img4.jpg";
  imgList["ref3"]["out"] = "img5.jpg";
  imgList["ref3"]["over"] = "img6.jpg";

//Add the swapping functions
  $("img").mouseover(function(){
    $(this).attr("src", imgList[ $(this).attr("id") ]["over"]);
  }

  $("img").mouseout(function(){
    $(this).attr("src", imgList[ $(this).attr("id") ]["out"]);
  }

$.browser is undefined error

The .browser call has been removed in jquery 1.9 have a look at http://jquery.com/upgrade-guide/1.9/ for more details.

Preloading images with JavaScript

Solution for ECMAScript 2017 compliant browsers

Note: this will also work if you are using a transpiler like Babel.

'use strict';

function imageLoaded(src, alt = '') {
    return new Promise(function(resolve) {
        const image = document.createElement('img');

        image.setAttribute('alt', alt);
        image.setAttribute('src', src);

        image.addEventListener('load', function() {
            resolve(image);
        });
    });
}

async function runExample() {
    console.log("Fetching my cat's image...");

    const myCat = await imageLoaded('https://placekitten.com/500');

    console.log("My cat's image is ready! Now is the time to load my dog's image...");

    const myDog = await imageLoaded('https://placedog.net/500');

    console.log('Whoa! This is now the time to enable my galery.');

    document.body.appendChild(myCat);
    document.body.appendChild(myDog);
}

runExample();

You could also have waited for all images to load.

async function runExample() {
    const [myCat, myDog] = [
        await imageLoaded('https://placekitten.com/500'),
        await imageLoaded('https://placedog.net/500')
    ];

    document.body.appendChild(myCat);
    document.body.appendChild(myDog);
}

Or use Promise.all to load them in parallel.

async function runExample() {
    const [myCat, myDog] = await Promise.all([
        imageLoaded('https://placekitten.com/500'),
        imageLoaded('https://placedog.net/500')
    ]);

    document.body.appendChild(myCat);
    document.body.appendChild(myDog);
}

More about Promises.

More about "Async" functions.

More about the destructuring assignment.

More about ECMAScript 2015.

More about ECMAScript 2017.

How do I run a shell script without using "sh" or "bash" commands?

Add a "shebang" at the top of your file:

#!/bin/bash

And make your file executable (chmod +x script.sh).

Finally, modify your path to add the directory where your script is located:

export PATH=$PATH:/appropriate/directory

(typically, you want $HOME/bin for storing your own scripts)

Replacing characters in Ant property

Use some external app like sed:

<exec executable="sed" inputstring="${wersja}" outputproperty="wersjaDot">
  <arg value="s/_/./g"/>
</exec>
<echo>${wersjaDot}</echo>

If you run Windows get it googling for "gnuwin32 sed".

The command s/_/./g replaces every _ with . This script goes well under windows. Under linux arg may need quoting.

nvm is not compatible with the npm config "prefix" option:

Just resolved the issue. I symlinked $HOME/.nvm to $DEV_ZONE/env/node/nvm directory. I was facing same issue. I replaced NVM_DIR in $HOME/.zshrc as follows

export NVM_DIR="$DEV_ZONE/env/node/nvm"

BTW, please install NVM using curl or wget command not by using brew. For more please check the comment in this issue on Github: 855#issuecomment-146115434

ASP.NET Forms Authentication failed for the request. Reason: The ticket supplied has expired

AS Scott mentioned here http://weblogs.asp.net/scottgu/archive/2010/09/30/asp-net-security-fix-now-on-windows-update.aspx After windows installed security update for .net framework, you will meet this problem. just modify the configuration section in your web.config file and switch to a different cookie name.

javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake during web service communicaiton

I faced the same issue once. I think its because of the URL

String xmlServerURL = "https://example.com/soap/WsRouter";

Check whether its a proper one or not ??

javax.net.ssl.SSLHandshakeException is because the server not able to connect to the specified URL because of following reason-

  • Either the identity of the website is not verified.
  • Server's certificate does not match the URL.
  • Or, Server's certificate is not trusted.

How do I resolve a HTTP 414 "Request URI too long" error?

I got this error after using $.getJSON() from JQuery. I just changed to post:

data = getDataObjectByForm(form);
var jqxhr = $.post(url, data, function(){}, 'json')
    .done(function (response) {
        if (response instanceof Object)
            var json = response;
        else
            var json = $.parseJSON(response);
        // console.log(response);
        // console.log(json);
        jsonToDom(json);
        if (json.reload != undefined && json.reload)
            location.reload();
        $("body").delay(1000).css("cursor", "default");
    })
    .fail(function (jqxhr, textStatus, error) {
        var err = textStatus + ", " + error;
        console.log("Request Failed: " + err);
        alert("Fehler!");
    });

Add element to a list In Scala

I will try to explain the results of all the commands you tried.

scala> val l = 1.0 :: 5.5 :: Nil
l: List[Double] = List(1.0, 5.5)

First of all, List is a type alias to scala.collection.immutable.List (defined in Predef.scala).

Using the List companion object is more straightforward way to instantiate a List. Ex: List(1.0,5.5)

scala> l
res0: List[Double] = List(1.0, 5.5)

scala> l ::: List(2.2, 3.7)
res1: List[Double] = List(1.0, 5.5, 2.2, 3.7)

::: returns a list resulting from the concatenation of the given list prefix and this list

The original List is NOT modified

scala> List(l) :+ 2.2
res2: List[Any] = List(List(1.0, 5.5), 2.2)

List(l) is a List[List[Double]] Definitely not what you want.

:+ returns a new list consisting of all elements of this list followed by elem.

The type is List[Any] because it is the common superclass between List[Double] and Double

scala> l
res3: List[Double] = List(1.0, 5.5)

l is left unmodified because no method on immutable.List modified the List.

How to check for null/empty/whitespace values with a single test?

The NULLIF function will convert any column value with only whitespace into a NULL value. Works for T-SQL and SQL Server 2008 & up.

SELECT [column_name]
FROM [table_name]
WHERE NULLIF([column_name], '') IS NULL

How to change a PG column to NULLABLE TRUE?

From the fine manual:

ALTER TABLE mytable ALTER COLUMN mycolumn DROP NOT NULL;

There's no need to specify the type when you're just changing the nullability.

Java: convert seconds to minutes, hours and days

Thanks guys for all the help, I really appreciate but I actually did some thinking and start doing some pseudo code and came up with this.

import java.util.Scanner;

public class Project {

public static void main(String[] args) {



//variable declaration  
Scanner scan = new Scanner(System.in);
final int MIN = 60, HRS = 3600, DYS = 84600;
int input, days, seconds, minutes, hours, rDays, rHours;

//input 
System.out.println("Enter amount of seconds!");
input = scan.nextInt();


//calculations
days = input/DYS;
rDays = input%DYS;
hours = rDays/HRS;
rHours = rDays%HRS;
minutes = rHours/MIN;
seconds = rHours%MIN;

//output
if (input >= DYS) {
    System.out.println(input + " seconds equals to " + days + " days " + hours + " hours " + minutes + " minutes " + seconds + " seconds");
}

else if (input >= HRS && input < DYS) {
    System.out.println(input + " seconds equals to " + hours + " hours " + minutes + " minutes " + seconds + " seconds");
}

else if (input >= MIN && input < HRS) {
    System.out.println(input + " seconds equals to " + minutes + " minutes " + seconds + " seconds");
}

else if (input < MIN) {
    System.out.println(input + " seconds equals to seconds");
}

scan.close();


}   

I know it looks really noobie but keep in mind I'm still new not just Java but programming entirely, and who knew pseudo code was actually really helpful.

Getting list of items inside div using Selenium Webdriver

You're asking for all the elements of class facetContainerDiv, of which there is only one (your outer-most div). Why not do

List<WebElement> checks =  driver.findElements(By.class("facetCheck"));
// click the 3rd checkbox
checks.get(2).click();

Count specific character occurrences in a string

Public Function CountOccurrences(ByVal StToSerach As String, ByVal StToLookFor As String) As Int32

    Dim iPos = -1
    Dim iFound = 0
    Do
        iPos = StToSerach.IndexOf(StToLookFor, iPos + 1)
        If iPos <> -1 Then
            iFound += 1
        End If<br/>
    Loop Until iPos = -1
    Return iFound
End Function

Code Usage:

Dim iCountTimes As Integer = CountOccurrences("Can I call you now?", "a")

Also you can have it as an extension:

<Extension()> _
Public Function CountOccurrences(ByVal StToSerach As String, ByVal StToLookFor As String) As Int32
    Dim iPos = -1
    Dim iFound = 0
    Do
        iPos = StToSerach.IndexOf(StToLookFor, iPos + 1)
        If iPos <> -1 Then
            iFound += 1
        End If
    Loop Until iPos = -1
    Return iFound
End Function

Code Usage:

Dim iCountTimes2 As Integer = "Can I call you now?".CountOccurrences("a")

C: What is the difference between ++i and i++?

The Main Difference is

  • i++ Post(After Increment) and
  • ++i Pre (Before Increment)

    • post if i =1 the loop increments like 1,2,3,4,n
    • pre if i =1 the loop increments like 2,3,4,5,n

Convert month int to month name

var monthIndex = 1;
return month = DateTimeFormatInfo.CurrentInfo.GetAbbreviatedMonthName(monthIndex);

You can try this one as well

Wait for shell command to complete

what you proposed with a change at the parenthesis at the Run command worked fine with VBA for me

Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1
Dim errorCode As Integer
wsh.Run "C:\folder\runbat.bat", windowStyle, waitOnReturn

Difference Between ViewResult() and ActionResult()

In Controller i have specified the below code with ActionResult which is a base class that can have 11 subtypes in MVC like: ViewResult, PartialViewResult, EmptyResult, RedirectResult, RedirectToRouteResult, JsonResult, JavaScriptResult, ContentResult, FileContentResult, FileStreamResult, FilePathResult.

    public ActionResult Index()
                {
                    if (HttpContext.Session["LoggedInUser"] == null)
                    {
                        return RedirectToAction("Login", "Home");
                    }

                    else
                    {
                        return View(); // returns ViewResult
                    }

                }
//More Examples

    [HttpPost]
    public ActionResult Index(string Name)
    {
     ViewBag.Message = "Hello";
     return Redirect("Account/Login"); //returns RedirectResult
    }

    [HttpPost]
    public ActionResult Index(string Name)
    {
    return RedirectToRoute("RouteName"); // returns RedirectToRouteResult
    }

Likewise we can return all these 11 subtypes by using ActionResult() without specifying every subtype method explicitly. ActionResult is the best thing if you are returning different types of views.

How to modify JsonNode in Java?

JsonNode is immutable and is intended for parse operation. However, it can be cast into ObjectNode (and ArrayNode) that allow mutations:

((ObjectNode)jsonNode).put("value", "NO");

For an array, you can use:

((ObjectNode)jsonNode).putArray("arrayName").add(object.ge??tValue());

Android Studio Checkout Github Error "CreateProcess=2" (Windows)

I found what I think is a faster solution. Install Git for Windows from here: http://git-scm.com/download/win

That automatically adds its path to the system variable during installation if you tell the installer to do so (it asks for that). So you don't have to edit anything manually.

Just close and restart Android Studio if it's open and you're ready to go.

wizard sample

Windows ignores JAVA_HOME: how to set JDK as default?

After struggling with this issue for some time and researching about it, I finally managed to solve it following these steps:

1) install jdk version 12
2) Create new variable in systems variable
3) Name it as JAVA_HOME and give jdk installation path
4) add this variable in path and move it to top.
5) go to C:\Program Files (86)\Common Files\Oracle\Java\javapath and replace java.exe and javaw.exe with the corresponding files with the same names from the pathtojavajdk/bin folder

Finally, I checked the default version of java in cmd with "java -version" and it worked!

Expanding a parent <div> to the height of its children

If your content inside #childRightCol and #childRightCol are floated left or right, just add this into css:

#childRightCol:before { display: table; content: " "; }
#childRightCol:after { display: table; content: " "; clear: both; }
#childLeftCol:before { display: table; content: " "; }
#childLeftCol:after { display: table; content: " "; clear: both; }

How can I add (simple) tracing in C#?

DotNetCoders has a starter article on it: http://www.dotnetcoders.com/web/Articles/ShowArticle.aspx?article=50. They talk about how to set up the switches in the configuration file and how to write the code, but it is pretty old (2002).

There's another article on CodeProject: A Treatise on Using Debug and Trace classes, including Exception Handling, but it's the same age.

CodeGuru has another article on custom TraceListeners: Implementing a Custom TraceListener

How do I refresh the page in ASP.NET? (Let it reload itself by code)

Try this:

Response.Redirect(Request.Url.AbsoluteUri);

What does the "On Error Resume Next" statement do?

It enables error handling. The following is partly from https://msdn.microsoft.com/en-us/library/5hsw66as.aspx

' Enable error handling. When a run-time error occurs, control goes to the statement 
' immediately following the statement where the error occurred, and execution
' continues from that point.
On Error Resume Next

SomeCodeHere

If Err.Number = 0 Then
    WScript.Echo "No Error in SomeCodeHere."
Else
  WScript.Echo "Error in SomeCodeHere: " & Err.Number & ", " & Err.Source & ", " & Err.Description
  ' Clear the error or you'll see it again when you test Err.Number
  Err.Clear
End If

SomeMoreCodeHere

If Err.Number <> 0 Then
  WScript.Echo "Error in SomeMoreCodeHere:" & Err.Number & ", " & Err.Source & ", " & Err.Description
  ' Clear the error or you'll see it again when you test Err.Number
  Err.Clear
End If

' Disables enabled error handler in the current procedure and resets it to Nothing.
On Error Goto 0

' There are also `On Error Goto -1`, which disables the enabled exception in the current 
' procedure and resets it to Nothing, and `On Error Goto line`, 
' which enables the error-handling routine that starts at the line specified in the 
' required line argument. The line argument is any line label or line number. If a run-time 
' error occurs, control branches to the specified line, making the error handler active. 
' The specified line must be in the same procedure as the On Error statement, 
' or a compile-time error will occur.

"break;" out of "if" statement?

As already mentioned that, break-statement works only with switches and loops. Here is another way to achieve what is being asked. I am reproducing https://stackoverflow.com/a/257421/1188057 as nobody else mentioned it. It's just a trick involving the do-while loop.

do {
  // do something
  if (error) {
    break;
  }
  // do something else
  if (error) {
    break;
  }
  // etc..
} while (0);

Though I would prefer the use of goto-statement.

ReportViewer Client Print Control "Unable to load client print control"?

Unable to load Client Print Control!
Everytime, clients wanted to print report by clicking the button print on their report viewer, they always got this error message.

I had spent nearly two weeks to fix this problem.
My environment is:
- Window Server 2003 Standard Edition R2
- Report Server Version 10.X.X.X
- Clients with windowXP SP3
My Solution is:
- Replacing the CAP file (RSClientPrint-x86.cab) in C\Program Files\Microsoft SQL
Server\MSRS10.MSSQLSERVER\Reporting Services\ReportServer\bin\
- Extract the RSClientPrint-x86.cab and destribute it to clients.


Hear is the CAB file: https://sites.google.com/site/narithsite/Home/RSClientPrint-x86.cab?attredirects=0&d=1

Pivoting rows into columns dynamically in Oracle

Oracle 11g provides a PIVOT operation that does what you want.

Oracle 11g solution

select * from
(select id, k, v from _kv) 
pivot(max(v) for k in ('name', 'age', 'gender', 'status')

(Note: I do not have a copy of 11g to test this on so I have not verified its functionality)

I obtained this solution from: http://orafaq.com/wiki/PIVOT

EDIT -- pivot xml option (also Oracle 11g)
Apparently there is also a pivot xml option for when you do not know all the possible column headings that you may need. (see the XML TYPE section near the bottom of the page located at http://www.oracle.com/technetwork/articles/sql/11g-pivot-097235.html)

select * from
(select id, k, v from _kv) 
pivot xml (max(v)
for k in (any) )

(Note: As before I do not have a copy of 11g to test this on so I have not verified its functionality)

Edit2: Changed v in the pivot and pivot xml statements to max(v) since it is supposed to be aggregated as mentioned in one of the comments. I also added the in clause which is not optional for pivot. Of course, having to specify the values in the in clause defeats the goal of having a completely dynamic pivot/crosstab query as was the desire of this question's poster.

Switch statement fallthrough in C#?

You can 'goto case label' http://www.blackwasp.co.uk/CSharpGoto.aspx

The goto statement is a simple command that unconditionally transfers the control of the program to another statement. The command is often criticised with some developers advocating its removal from all high-level programming languages because it can lead to spaghetti code. This occurs when there are so many goto statements or similar jump statements that the code becomes difficult to read and maintain. However, there are programmers who point out that the goto statement, when used carefully, provides an elegant solution to some problems...

Correct modification of state arrays in React.js

This code work for me:

fetch('http://localhost:8080')
  .then(response => response.json())
  .then(json => {
    this.setState({mystate: this.state.mystate.push.apply(this.state.mystate, json)})
  })

GnuPG: "decryption failed: secret key not available" error from gpg on Windows

Yes, your secret key appears to be missing. Without it, you will not be able to decrypt the files.

Do you have the key backed up somewhere?

Re-creating the keys, whether you use the same passphrase or not, will not work. Each key pair is unique.

How to get a list of all files that changed between two Git commits?

With git show you can get a similar result. For look the commit (like it looks on git log view) with the list of files included in, use:

git show --name-only [commit-id_A]^..[commit-id_B]

Where [commit-id_A] is the initial commit and [commit-id_B] is the last commit than you want to show.

Special attention with ^ symbol. If you don't put that, the commit-id_A information will not deploy.

RSA: Get exponent and modulus given a public key

Apart from the above answers, we can use asn1parse to get the values

$ openssl asn1parse -i -in pub0.der -inform DER -offset 24
0:d=0  hl=4 l= 266 cons: SEQUENCE
4:d=1  hl=4 l= 257 prim:  INTEGER           :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
265:d=1  hl=2 l= 3 prim:  INTEGER           :010001

Now, to get to this offset,we try the default asn1parse

$ openssl asn1parse -i -in pub0.der -inform DER
 0:d=0  hl=4 l= 290 cons: SEQUENCE
 4:d=1  hl=2 l=  13 cons:  SEQUENCE
 6:d=2  hl=2 l=   9 prim:   OBJECT            :rsaEncryption
17:d=2  hl=2 l=   0 prim:   NULL
19:d=1  hl=4 l= 271 prim:  BIT STRING

We need to get to the BIT String part, so we add the sizes

depth_0_header(4) + depth_1_full_size(2 + 13) + Container_1_EOC_bit + BIT_STRING_header(4) = 24

This can be better visialized at: ASN.1 Parser, if you hover at tags, you will see the offsets

Another amazing resource: Microsoft's ASN.1 Docs

Make WPF Application Fullscreen (Cover startmenu)

You're probably missing the WindowState="Maximized", try the following:

<Window x:Class="HTA.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525"
    WindowStyle="None" ResizeMode="NoResize"  
    WindowStartupLocation="CenterScreen" WindowState="Maximized">

How to use Git for Unity3D source control?

I wanted to add a very simple workflow from someone who has been frustrated with git in the past. There are several ways to use git, probably the most common for unity are GitHub Desktop, Git Bash and GitHub Unity

https://assetstore.unity.com/packages/tools/version-control/github-for-unity-118069.

Essentially they all do the same thing but its user choice. You can have git for large file setup which allows 1GB free large file storage with additional storage available in data packs for $4/mo for 50GB, and this will allow you to push files >100mb to remote repositories (it stores the actual files on a server and in your repo a pointer)

https://git-lfs.github.com/

If you don't want to setup lfs for whatever reason you can scan your projects for files > 128 mb in windows by typing size:large in the directory where you have your project. This can be handy to search for large files, although there may be some files between 100mb and 128mb that get missed.

enter image description here

The general format of git bash is

git add . (adds files to be commited)

git commit -m 'message' (commits the files with a message, they are still on your pc and not in the remote repo, basically they have been 'versioned' as a new commit)

git push (push files to the repository)

The disadvantage of git bash for unity projects is that if there is a file > 100mb, you won't get an error until you push. You then have to undo your commit by resetting your head to the previous commit. Kind of a hassle, especially if you are new with git bash.

The advantage of GitHub Desktop, is BEFORE you commit files with 100mb it will give you a popup error message. You can then shrink those files or add them to a .gitignore file.

To use a .gitignore file, create a file called .gitignore in your local repository root directory. Simply add the files one line at a time you would like to omit. SharedAssets and other non-Asset folder files can usually be omitted and will automatically repopulate in the editor (packages can be re-imported etc). You can also use wildcards to exclude file types.

If other people are using your GitHub repo and you want to clone or pull you have those options available to you as well on GitHub desktop or Git bash.

I did not mention much about Unity GitHub package where you can use GitHub in the editor because personally I did not find the interface very useful, and I don't think overall its going to help anyone get familiar with git, but this is just my preference.

Drag and drop menuitems

jQuery UI draggable and droppable are the two plugins I would use to achieve this effect. As for the insertion marker, I would investigate modifying the div (or container) element that was about to have content dropped into it. It should be possible to modify the border in some way or add a JavaScript/jQuery listener that listens for the hover (element about to be dropped) event and modifies the border or adds an image of the insertion marker in the right place.

Make a link open a new window (not tab)

I know that its bit old Q but if u get here by searching a solution so i got a nice one via jquery

  jQuery('a[target^="_new"]').click(function() {
    var width = window.innerWidth * 0.66 ;
    // define the height in
    var height = width * window.innerHeight / window.innerWidth ;
    // Ratio the hight to the width as the user screen ratio
    window.open(this.href , 'newwindow', 'width=' + width + ', height=' + height + ', top=' + ((window.innerHeight - height) / 2) + ', left=' + ((window.innerWidth - width) / 2));

});

it will open all the <a target="_new"> in a new window

EDIT:

1st, I did some little changes in the original code now it open the new window perfectly followed the user screen ratio (for landscape desktops)

but, I would like to recommend you to use the following code that open the link in new tab if you in mobile (thanks to zvona answer in other question):

jQuery('a[target^="_new"]').click(function() {
    return openWindow(this.href);
}


function openWindow(url) {

    if (window.innerWidth <= 640) {
        // if width is smaller then 640px, create a temporary a elm that will open the link in new tab
        var a = document.createElement('a');
        a.setAttribute("href", url);
        a.setAttribute("target", "_blank");

        var dispatch = document.createEvent("HTMLEvents");
        dispatch.initEvent("click", true, true);

        a.dispatchEvent(dispatch);
    }
    else {
        var width = window.innerWidth * 0.66 ;
        // define the height in
        var height = width * window.innerHeight / window.innerWidth ;
        // Ratio the hight to the width as the user screen ratio
        window.open(url , 'newwindow', 'width=' + width + ', height=' + height + ', top=' + ((window.innerHeight - height) / 2) + ', left=' + ((window.innerWidth - width) / 2));
    }
    return false;
}

database attached is read only

If you have tried all of this and still no luck, try the detach/attach again.

calling another method from the main method in java

First java will not allow you to have do() method. Instead you can make it doOperation().

Second You cann't invoke directly non static methods from static function. Main is a static function. You need to instantiate the class first and then invoke method using that instance.

Third you can invoke static method directly from non static methods.

get list of packages installed in Anaconda

For more conda list usage details:

usage: conda-script.py list [-h][-n ENVIRONMENT | -p PATH][--json] [-v] [-q]
[--show-channel-urls] [-c] [-f] [--explicit][--md5] [-e] [-r] [--no-pip][regex]

Java command not found on Linux

I found the best way for me was to download unzip then symlink your new usr/java/jre-version/bin/java to your main bin as java.

Node.js: socket.io close client connection

try this to close the connection:

socket.close();

and if you want to open it again:

socket.connect();

Reset all the items in a form

    function setToggleInputsinPnl(pnlName) {
    var domCount = pnlName.length;
    for (var i = 0; i < domCount; i++) {
        if (pnlName[i].type == 'text') {
            pnlName[i].value = '';
        } else if (pnlName[i].type == 'select-one') {
               pnlName[i].value = '';
        }
    }
}

Receiving "Attempted import error:" in react app

import { combineReducers } from '../../store/reducers';

should be

import combineReducers from '../../store/reducers';

since it's a default export, and not a named export.

There's a good breakdown of the differences between the two here.

Convert byte[] to char[]

byte[] a = new byte[50];

char [] cArray= System.Text.Encoding.ASCII.GetString(a).ToCharArray();

From the URL thedixon posted

http://bytes.com/topic/c-sharp/answers/250261-byte-char

You cannot ToCharArray the byte without converting it to a string first.

To quote Jon Skeet there

There's no need for the copying here - just use Encoding.GetChars. However, there's no guarantee that ASCII is going to be the appropriate encoding to use.

Why can't I change my input value in React even with the onChange listener

You can do shortcut via inline function if you want to simply change the state variable without declaring a new function at top:

<input type="text" onChange={e => this.setState({ text: e.target.value })}/>

Difference between EXISTS and IN in SQL?

IN supports only equality relations (or inequality when preceded by NOT).
It is a synonym to =any / =some, e.g

select    * 
from      t1 
where     x in (select x from t2)
;

EXISTS supports variant types of relations, that cannot be expressed using IN, e.g. -

select    * 
from      t1 
where     exists (select    null 
                  from      t2 
                  where     t2.x=t1.x 
                        and t2.y>t1.y 
                        and t2.z like '?' || t1.z || '?'
                  )
;

And on a different note -

The allegedly performance and technical differences between EXISTS and IN may result from specific vendor's implementations/limitations/bugs, but many times they are nothing but myths created due to lack of understanding of the databases internals.

The tables' definition, statistics' accuracy, database configuration and optimizer's version have all impact on the execution plan and therefore on the performance metrics.

how to modify the size of a column

This was done using Toad for Oracle 12.8.0.49

ALTER TABLE SCHEMA.TABLENAME 
    MODIFY (COLUMNNAME NEWDATATYPE(LENGTH)) ;

For example,

ALTER TABLE PAYROLL.EMPLOYEES 
    MODIFY (JOBTITLE VARCHAR2(12)) ;

Easiest way to parse a comma delimited string to some kind of object I can loop through to access the individual values?

The pattern matches all non-digit characters. This will restrict you to non-negative integers, but for your example it will be more than sufficient.

string input = "0, 10, 20, 30, 100, 200";
Regex.Split(input, @"\D+");

How to select a record and update it, with a single queryset in Django?

Use the queryset object update method:

MyModel.objects.filter(pk=some_value).update(field1='some value')

How to Round to the nearest whole number in C#

If your working with integers rather than floating point numbers, here is the way.

#define ROUNDED_FRACTION(numr,denr) ((numr/denr)+(((numr%denr)<(denr/2))?0:1))

Here both "numr" and "denr" are unsigned integers.

Setting POST variable without using form

Yes, simply set it to another value:

$_POST['text'] = 'another value';

This will override the previous value corresponding to text key of the array. The $_POST is superglobal associative array and you can change the values like a normal PHP array.

Caution: This change is only visible within the same PHP execution scope. Once the execution is complete and the page has loaded, the $_POST array is cleared. A new form submission will generate a new $_POST array.

If you want to persist the value across form submissions, you will need to put it in the form as an input tag's value attribute or retrieve it from a data store.

How to configure Chrome's Java plugin so it uses an existing JDK in the machine

I came across a similar issue but instead of changing the regedit I decided to change the Chrome settings

Try the following steps

  1. In the chrome browser type: chrome://plugins/
  2. Click on + Details (top right corner) to expand all the plugin details.
  3. Find Java and click on Disable for the path(s) that you don't want to be used.

You might have to restart the browser to see the changes. This also assumes that the Java that you have enabled is the latest Java.

Hope this helps

Storing and displaying unicode string (??????) using PHP and MySQL

For Those who are facing difficulty just got to php admin and change collation to utf8_general_ci Select Table go to Operations>> table options>> collations should be there

How do I get an OAuth 2.0 authentication token in C#

This example get token thouth HttpWebRequest

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(pathapi);
        request.Method = "POST";
        string postData = "grant_type=password";
        ASCIIEncoding encoding = new ASCIIEncoding();
        byte[] byte1 = encoding.GetBytes(postData);

        request.ContentType = "application/x-www-form-urlencoded";

        request.ContentLength = byte1.Length;
        Stream newStream = request.GetRequestStream();
        newStream.Write(byte1, 0, byte1.Length);

        HttpWebResponse response = request.GetResponse() as HttpWebResponse;            
        using (Stream responseStream = response.GetResponseStream())
        {
            StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);
            getreaderjson = reader.ReadToEnd();
        }

Android Firebase, simply get one child object's data

just fetch specific node data and its working perfect for me

mFirebaseInstance.getReference("yourNodeName").getRef().addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {


        for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
            Log.e(TAG, "======="+postSnapshot.child("email").getValue());
            Log.e(TAG, "======="+postSnapshot.child("name").getValue());
        }
    }

    @Override
    public void onCancelled(DatabaseError error) {
        // Failed to read value
        Log.e(TAG, "Failed to read app title value.", error.toException());
    }
});

How to allow http content within an iframe on a https site

Using Google as the SSL proxy is not working currently,

Why?

If you opened any page from google, you will find there is a x-frame-options field in the header. Google response header

The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a <frame>, <iframe> or <object>. Sites can use this to avoid clickjacking attacks, by ensuring that their content is not embedded into other sites.

(Quote from MDN)

One of the solution

Below is my work around for this problem:

Upload the content to AWS S3, and it will create a https link for the resource.
Notice: set the permission to the html file for allowing everyone view it.

After that, we can using it as the src of iframe in the https websites. AWS

Android appcompat v7:23

Latest published version of the Support Library is 24.1.1, So you can use it like this,

compile 'com.android.support:appcompat-v7:24.1.1'
compile 'com.android.support:design:24.1.1'

Same as for other support components.

You can see the revisions here,
https://developer.android.com/topic/libraries/support-library/revisions.html

How to remove white space characters from a string in SQL Server

In that case, it isn't space that is in prefix/suffix.
The 1st row looks OK. Do the following for the contents of 2nd row.

ASCII(RIGHT(ProductAlternateKey, 1))

and

ASCII(LEFT(ProductAlternateKey, 1))

.htaccess not working apache

By default, Apache prohibits using an .htaccess file to apply rewrite rules, so

Step 1 — Enabling mod_rewrite (if not Enabled) First, we need to activate mod_rewrite. It's available but not enabled with a clean Apache 2 installation.

$ sudo a2enmod rewrite

This will activate the module or alert you that the module is already enabled. To put these changes into effect, restart Apache.

$ sudo systemctl restart apache2

mod_rewrite is now fully enabled. In the next step we will set up an .htaccess file that we'll use to define rewrite rules for redirects.

Step 2 — Setting Up .htaccess Open the default Apache configuration file using nano or your favorite text editor.

$ sudo nano /etc/apache2/sites-available/000-default.conf

Inside that file, you will find a block starting on the first line. Inside of that block, add the following new block so your configuration file looks like the following. Make sure that all blocks are properly indented.

/etc/apache2/sites-available/000-default.conf

<VirtualHost *:80>
    <Directory /var/www/html>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Require all granted
    </Directory>

    . . . 
</VirtualHost>

Save and close the file. To put these changes into effect, restart Apache.

$ sudo systemctl restart apache2

Done. Your .htacess should work. This link may actually help somebody https://www.digitalocean.com/community/tutorials/how-to-rewrite-urls-with-mod_rewrite-for-apache-on-ubuntu-16-04

What is the equivalent of the C++ Pair<L,R> in Java?

You can use javafx utility class, Pair which serves the same purpose as pair <> in c++. https://docs.oracle.com/javafx/2/api/javafx/util/Pair.html

Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

Tank´s Yogihosting

I have in my database one goups of tables from Open Streep Maps and I tested successful.

Distance work fine in meters.

SET @orig_lat=-8.116137;
SET @orig_lon=-34.897488;
SET @dist=1000;

SELECT *,(((acos(sin((@orig_lat*pi()/180)) * sin((dest.latitude*pi()/180))+cos((@orig_lat*pi()/180))*cos((dest.latitude*pi()/180))*cos(((@orig_lon-dest.longitude)*pi()/180))))*180/pi())*60*1.1515*1609.344) as distance FROM nodes AS dest HAVING distance < @dist ORDER BY distance ASC LIMIT 100;

Stopping a thread after a certain amount of time

If you want the threads to stop when your program exits (as implied by your example), then make them daemon threads.

If you want your threads to die on command, then you have to do it by hand. There are various methods, but all involve doing a check in your thread's loop to see if it's time to exit (see Nix's example).

Remove ListView items in Android

You will want to remove() the item from your adapter object and then just run the notifyDatasetChanged() on the Adapter, any ListViews will (should) recycle and update on it's own.

Here's a brief activity example with AlertDialogs:

adapter = new MyListAdapter(this);
    lv = (ListView) findViewById(android.R.id.list);
    lv.setAdapter(adapter);
    lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> a, View v, int position, long id) {
        AlertDialog.Builder adb=new AlertDialog.Builder(MyActivity.this);
        adb.setTitle("Delete?");
        adb.setMessage("Are you sure you want to delete " + position);
        final int positionToRemove = position;
        adb.setNegativeButton("Cancel", null);
        adb.setPositiveButton("Ok", new AlertDialog.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                MyDataObject.remove(positionToRemove);
                adapter.notifyDataSetChanged();
            }});
        adb.show();
        }
    });

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

As others have answered, this breaks because .ToString fails to translate to relevant SQL on the way into the database.

However, Microsoft provides the SqlFunctions class that is a collection of methods that can be used in situations like this.

For this case, what you are looking for here is SqlFunctions.StringConvert:

from p in context.pages
where  p.Serial == SqlFunctions.StringConvert((double)item.Key.Id)
select p;

Good when the solution with temporary variables is not desirable for whatever reasons.

Similar to SqlFunctions you also have the EntityFunctions (with EF6 obsoleted by DbFunctions) that provides a different set of functions that also are data source agnostic (not limited to e.g. SQL).

Convert String XML fragment to Document Node in Java

Try jcabi-xml, with a one liner:

Node node = new XMLDocument("<node>value</node>").node();

How to use a jQuery plugin inside Vue

I use it like this:

import jQuery from 'jQuery'

ready: function() {
    var self = this;
    jQuery(window).resize(function () {
      self.$refs.thisherechart.drawChart();
    })
  },

How do I link to a library with Code::Blocks?

The gdi32 library is already installed on your computer, few programs will run without it. Your compiler will (if installed properly) normally come with an import library, which is what the linker uses to make a binding between your program and the file in the system. (In the unlikely case that your compiler does not come with import libraries for the system libs, you will need to download the Microsoft Windows Platform SDK.)

To link with gdi32:

enter image description here

This will reliably work with MinGW-gcc for all system libraries (it should work if you use any other compiler too, but I can't talk about things I've not tried). You can also write the library's full name, but writing libgdi32.a has no advantage over gdi32 other than being more type work.
If it does not work for some reason, you may have to provide a different name (for example the library is named gdi32.lib for MSVC).

For libraries in some odd locations or project subfolders, you will need to provide a proper pathname (click on the "..." button for a file select dialog).

Laravel - check if Ajax request

You are using the wrong Request class. If you want to use the Facade like: Request::ajax() you have to import this class:

use Illuminate\Support\Facades\Request;

And not Illumiante\Http\Request


Another solution would be injecting an instance of the real request class:

public function index(Request $request){
    if($request->ajax()){
        return "AJAX";
    }

(Now here you have to import Illuminate\Http\Request)

Create table in SQLite only if it doesn't exist already

Am going to try and add value to this very good question and to build on @BrittonKerin's question in one of the comments under @David Wolever's fantastic answer. Wanted to share here because I had the same challenge as @BrittonKerin and I got something working (i.e. just want to run a piece of code only IF the table doesn't exist).

        # for completeness lets do the routine thing of connections and cursors
        conn = sqlite3.connect(db_file, timeout=1000) 

        cursor = conn.cursor() 

        # get the count of tables with the name  
        tablename = 'KABOOM' 
        cursor.execute("SELECT count(name) FROM sqlite_master WHERE type='table' AND name=? ", (tablename, ))

        print(cursor.fetchone()) # this SHOULD BE in a tuple containing count(name) integer.

        # check if the db has existing table named KABOOM
        # if the count is 1, then table exists 
        if cursor.fetchone()[0] ==1 : 
            print('Table exists. I can do my custom stuff here now.... ')
            pass
        else: 
           # then table doesn't exist. 
           custRET = myCustFunc(foo,bar) # replace this with your custom logic

How to add message box with 'OK' button?

@Override
protected Dialog onCreateDialog(int id)
{
    switch(id)
    {
    case 0:
    {               
        return new AlertDialog.Builder(this)
        .setMessage("text here")
        .setPositiveButton("OK", new DialogInterface.OnClickListener() 
        {                   
            @Override
            public void onClick(DialogInterface arg0, int arg1) 
            {
                try
                {

                }//end try
                catch(Exception e)
                {
                    Toast.makeText(getBaseContext(),  "", Toast.LENGTH_LONG).show();
                }//end catch
            }//end onClick()
        }).create();                
    }//end case
  }//end switch
    return null;
}//end onCreateDialog

Eclipse - no Java (JRE) / (JDK) ... no virtual machine

First go to computer then properties then advanced system settings then advanced

(3rd menu)

and then click environment variables button at the bottom.

To path in environment variables you add:

C:\Program Files\Java\jdk1.8.0_102\bin\;C:\Program Files\Java\jdk1.8.0_102\lib\; 

and the error will go away. This is the best one.

The other way is to copy the jre folder (C:\Program Files\Java\jre1.8.0_102) to

E:\eclipse-jee-indigo-SR2-win32\eclipse

folder. Then the error will go away.

How to calculate md5 hash of a file using javascript

hope you have found a good solution by now. If not, the solution below is an ES6 promise implementation based on js-spark-md5

import SparkMD5 from 'spark-md5';

// Read in chunks of 2MB
const CHUCK_SIZE = 2097152;

/**
 * Incrementally calculate checksum of a given file based on MD5 algorithm
 */
export const checksum = (file) =>
  new Promise((resolve, reject) => {
    let currentChunk = 0;
    const chunks = Math.ceil(file.size / CHUCK_SIZE);
    const blobSlice =
      File.prototype.slice ||
      File.prototype.mozSlice ||
      File.prototype.webkitSlice;
    const spark = new SparkMD5.ArrayBuffer();
    const fileReader = new FileReader();

    const loadNext = () => {
      const start = currentChunk * CHUCK_SIZE;
      const end =
        start + CHUCK_SIZE >= file.size ? file.size : start + CHUCK_SIZE;

      // Selectively read the file and only store part of it in memory.
      // This allows client-side applications to process huge files without the need for huge memory
      fileReader.readAsArrayBuffer(blobSlice.call(file, start, end));
    };

    fileReader.onload = e => {
      spark.append(e.target.result);
      currentChunk++;

      if (currentChunk < chunks) loadNext();
      else resolve(spark.end());
    };

    fileReader.onerror = () => {
      return reject('Calculating file checksum failed');
    };

    loadNext();
  });

Text not wrapping in p tag

Adding width: 100%; to the offending p element solved the problem for me. I don't know why it works.

NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

I have also encountered this error . Just i opened the new window ie Window -> New Window in eclipse .Then , I closed my old window. This solved my problem.

How to have css3 animation to loop forever

I stumbled upon the same problem: a page with many independent animations, each one with its own parameters, which must be repeated forever.

Merging this clue with this other clue I found an easy solution: after the end of all your animations the wrapping div is restored, forcing the animations to restart.

All you have to do is to add these few lines of Javascript, so easy they don't even need any external library, in the <head> section of your page:

<script>
setInterval(function(){
var container = document.getElementById('content');
var tmp = container.innerHTML;
container.innerHTML= tmp;
}, 35000 // length of the whole show in milliseconds
);
</script>

BTW, the closing </head> in your code is misplaced: it must be before the starting <body>.

How do I position an image at the bottom of div?

< img style="vertical-align: bottom" src="blah.png" >

Works for me. Inside a parallax div as well.

Angularjs if-then-else construction in expression

You can use ternary operator since version 1.1.5 and above like demonstrated in this little plunker (example in 1.1.5):

For history reasons (maybe plnkr.co get down for some reason in the future) here is the main code of my example:

{{true?true:false}}

Combining node.js and Python

I've had a lot of success using thoonk.js along with thoonk.py. Thoonk leverages Redis (in-memory key-value store) to give you feed (think publish/subscribe), queue and job patterns for communication.

Why is this better than unix sockets or direct tcp sockets? Overall performance may be decreased a little, however Thoonk provides a really simple API that simplifies having to manually deal with a socket. Thoonk also helps make it really trivial to implement a distributed computing model that allows you to scale your python workers to increase performance, since you just spin up new instances of your python workers and connect them to the same redis server.

How do I copy directories recursively with gulp?

So - the solution of providing a base works given that all of the paths have the same base path. But if you want to provide different base paths, this still won't work.

One way I solved this problem was by making the beginning of the path relative. For your case:

gulp.src([
    'index.php',
    '*css/**/*',
    '*js/**/*',
    '*src/**/*',
])
.pipe(gulp.dest('/var/www/'));

The reason this works is that Gulp sets the base to be the end of the first explicit chunk - the leading * causes it to set the base at the cwd (which is the result that we all want!)

This only works if you can ensure your folder structure won't have certain paths that could match twice. For example, if you had randomjs/ at the same level as js, you would end up matching both.

This is the only way that I have found to include these as part of a top-level gulp.src function. It would likely be simple to create a plugin/function that could separate out each of those globs so you could specify the base directory for them, however.

How enable auto-format code for Intellij IDEA?

if you want, you can use a saveActions plugin. You can reformat file, optimized the imports and more things, it's really customizable and easy to setup.

How can I get table names from an MS Access Database?

Schema information which is designed to be very close to that of the SQL-92 INFORMATION_SCHEMA may be obtained for the Jet/ACE engine (which is what I assume you mean by 'access') via the OLE DB providers.

See:

OpenSchema Method (ADO)

Supported Schema Rowsets

How to run ~/.bash_profile in mac terminal

You would never want to run that, but you may want to source it.

. ~/.bash_profile
source ~/.bash_profile

both should work. But this is an odd request, because that file should be sourced automatically when you start bash, unless you're explicitly starting it non-interactively. From the man page:

When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

Best data type to store money values in MySQL

If your application needs to handle money values up to a trillion then this should work: 13,2 If you need to comply with GAAP (Generally Accepted Accounting Principles) then use: 13,4

Usually you should sum your money values at 13,4 before rounding of the output to 13,2.

Actionbar notification count icon (badge) like Google has

Try looking at the answers to these questions, particularly the second one which has sample code:

How to implement dynamic values on menu item in Android

How to get text on an ActionBar Icon?

From what I see, You'll need to create your own custom ActionView implementation. An alternative might be a custom Drawable. Note that there appears to be no native implementation of a notification count for the Action Bar.

EDIT: The answer you were looking for, with code: Custom Notification View with sample implementation

What does the 'b' character do in front of a string literal?

To quote the Python 2.x documentation:

A prefix of 'b' or 'B' is ignored in Python 2; it indicates that the literal should become a bytes literal in Python 3 (e.g. when code is automatically converted with 2to3). A 'u' or 'b' prefix may be followed by an 'r' prefix.

The Python 3 documentation states:

Bytes literals are always prefixed with 'b' or 'B'; they produce an instance of the bytes type instead of the str type. They may only contain ASCII characters; bytes with a numeric value of 128 or greater must be expressed with escapes.

What values can I pass to the event attribute of the f:ajax tag?

The event attribute of <f:ajax> can hold at least all supported DOM events of the HTML element which is been generated by the JSF component in question. An easy way to find them all out is to check all on* attribues of the JSF input component of interest in the JSF tag library documentation and then remove the "on" prefix. For example, the <h:inputText> component which renders <input type="text"> lists the following on* attributes (of which I've already removed the "on" prefix so that it ultimately becomes the DOM event type name):

  • blur
  • change
  • click
  • dblclick
  • focus
  • keydown
  • keypress
  • keyup
  • mousedown
  • mousemove
  • mouseout
  • mouseover
  • mouseup
  • select

Additionally, JSF has two more special event names for EditableValueHolder and ActionSource components, the real HTML DOM event being rendered depends on the component type:

  • valueChange (will render as change on text/select inputs and as click on radio/checkbox inputs)
  • action (will render as click on command links/buttons)

The above two are the default events for the components in question.

Some JSF component libraries have additional customized event names which are generally more specialized kinds of valueChange or action events, such as PrimeFaces <p:ajax> which supports among others tabChange, itemSelect, itemUnselect, dateSelect, page, sort, filter, close, etc depending on the parent <p:xxx> component. You can find them all in the "Ajax Behavior Events" subsection of each component's chapter in PrimeFaces Users Guide.

cast class into another class or convert class to another

By using following code you can copy any class object to another class object for same name and same type of properties.

public class CopyClass
{
    /// <summary>
    /// Copy an object to destination object, only matching fields will be copied
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="sourceObject">An object with matching fields of the destination object</param>
    /// <param name="destObject">Destination object, must already be created</param>
    public static void CopyObject<T>(object sourceObject, ref T destObject)
    {
        //  If either the source, or destination is null, return
        if (sourceObject == null || destObject == null)
            return;

        //  Get the type of each object
        Type sourceType = sourceObject.GetType();
        Type targetType = destObject.GetType();

        //  Loop through the source properties
        foreach (PropertyInfo p in sourceType.GetProperties())
        {
            //  Get the matching property in the destination object
            PropertyInfo targetObj = targetType.GetProperty(p.Name);
            //  If there is none, skip
            if (targetObj == null)
                continue;

            //  Set the value in the destination
            targetObj.SetValue(destObject, p.GetValue(sourceObject, null), null);
        }
    }
}

Call Method Like,

ClassA objA = new ClassA();
ClassB objB = new ClassB();

CopyClass.CopyObject(objOfferMast, ref objB);

It will copy objA into objB.

How can I change IIS Express port for a site

I'm using VS 2019.

if your solution has more than one project / class libraries etc, then you may not see the Web tab when clicking on Solution explorer properties.

Clicking on the MVC project and then checking properties will reveal the web tab where you can change the port.

How to send image to PHP file using Ajax?

Jquery code which contains simple ajax :

   $("#product").on("input", function(event) {
      var data=$("#nameform").serialize();
    $.post("./__partails/search-productbyCat.php",data,function(e){
       $(".result").empty().append(e);

     });


    });

Html elements you can use any element:

     <form id="nameform">
     <input type="text" name="product" id="product">
     </form>

php Code:

  $pdo=new PDO("mysql:host=localhost;dbname=onlineshooping","root","");
  $Catagoryf=$_POST['product'];

 $pricef=$_POST['price'];
  $colorf=$_POST['color'];

  $stmtcat=$pdo->prepare('SELECT * from products where Catagory =?');
  $stmtcat->execute(array($Catagoryf));

  while($result=$stmtcat->fetch(PDO::FETCH_ASSOC)){
  $iddb=$result['ID'];
     $namedb=$result['Name'];
    $pricedb=$result['Price'];
     $colordb=$result['Color'];

   echo "<tr>";
   echo "<td><a href=./pages/productsinfo.php?id=".$iddb."> $namedb</a> </td>".'<br>'; 
   echo "<td><pre>$pricedb</pre></td>";
   echo "<td><pre>    $colordb</pre>";
   echo "</tr>";

The easy way

How to set a header for a HTTP GET request, and trigger file download?

i want to post my solution here which was done AngularJS, ASP.NET MVC. The code illustrates how to download file with authentication.

WebApi method along with helper class:

[RoutePrefix("filess")]
class FileController: ApiController
{
    [HttpGet]
    [Route("download-file")]
    [Authorize(Roles = "admin")]
    public HttpResponseMessage DownloadDocument([FromUri] int fileId)
    {
        var file = "someFile.docx"// asking storage service to get file path with id
        return Request.ReturnFile(file);
    }
}

static class DownloadFIleFromServerHelper
{
    public static HttpResponseMessage ReturnFile(this HttpRequestMessage request, string file)
    {
        var result = request.CreateResponse(HttpStatusCode.OK);

        result.Content = new StreamContent(new FileStream(file, FileMode.Open, FileAccess.Read));
        result.Content.Headers.Add("x-filename", Path.GetFileName(file)); // letters of header names will be lowercased anyway in JS.
        result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
        {
            FileName = Path.GetFileName(file)
        };

        return result;
    }
}

Web.config file changes to allow sending file name in custom header.

<configuration>
    <system.webServer>
        <httpProtocol>
            <customHeaders>
                <add name="Access-Control-Allow-Methods" value="POST,GET,PUT,PATCH,DELETE,OPTIONS" />
                <add name="Access-Control-Allow-Headers" value="Authorization,Content-Type,x-filename" />
                <add name="Access-Control-Expose-Headers" value="Authorization,Content-Type,x-filename" />
                <add name="Access-Control-Allow-Origin" value="*" />

Angular JS Service Part:

function proposalService($http, $cookies, config, FileSaver) {
        return {
                downloadDocument: downloadDocument
        };

    function downloadFile(documentId, errorCallback) {
    $http({
        url: config.apiUrl + "files/download-file?documentId=" + documentId,
        method: "GET",
        headers: {
            "Content-type": "application/json; charset=utf-8",
            "Authorization": "Bearer " + $cookies.get("api_key")
        },
        responseType: "arraybuffer"  
        })
    .success( function(data, status, headers) {
        var filename = headers()['x-filename'];

        var blob = new Blob([data], { type: "application/octet-binary" });
        FileSaver.saveAs(blob, filename);
    })
    .error(function(data, status) {
        console.log("Request failed with status: " + status);
        errorCallback(data, status);
    });
};
};

Module dependency for FileUpload: angular-file-download (gulp install angular-file-download --save). Registration looks like below.

var app = angular.module('cool',
[
    ...
    require('angular-file-saver'),
])
. // other staff.

Converting RGB to grayscale/intensity

What is the source of these values?

The "source" of the coefficients posted are the NTSC specifications which can be seen in Rec601 and Characteristics of Television.

The "ultimate source" are the CIE circa 1931 experiments on human color perception. The spectral response of human vision is not uniform. Experiments led to weighting of tristimulus values based on perception. Our L, M, and S cones1 are sensitive to the light wavelengths we identify as "Red", "Green", and "Blue" (respectively), which is where the tristimulus primary colors are derived.2

The linear light3 spectral weightings for sRGB (and Rec709) are:

Rlin * 0.2126 + Glin * 0.7152 + Blin * 0.0722 = Y

These are specific to the sRGB and Rec709 colorspaces, which are intended to represent computer monitors (sRGB) or HDTV monitors (Rec709), and are detailed in the ITU documents for Rec709 and also BT.2380-2 (10/2018)

FOOTNOTES (1) Cones are the color detecting cells of the eye's retina.
(2) However, the chosen tristimulus wavelengths are NOT at the "peak" of each cone type - instead tristimulus values are chosen such that they stimulate on particular cone type substantially more than another, i.e. separation of stimulus.
(3) You need to linearize your sRGB values before applying the coefficients. I discuss this in another answer here.

Uninstall Django completely

Remove any old versions of Django

If you are upgrading your installation of Django from a previous version, you will need to uninstall the old Django version before installing the new version.

If you installed Django using pip or easy_install previously, installing with pip or easy_install again will automatically take care of the old version, so you don’t need to do it yourself.

If you previously installed Django using python setup.py install, uninstalling is as simple as deleting the django directory from your Python site-packages. To find the directory you need to remove, you can run the following at your shell prompt (not the interactive Python prompt):

$ python -c "import django; print(django.path)"

How to refresh activity after changing language (Locale) inside application

This approach will work on all API level device.

  1. Use Base Activity for attachBaseContext to set the locale language and extend this activity for all activities

    open class  BaseAppCompactActivity() : AppCompatActivity() {
    
        override fun attachBaseContext(newBase: Context) {
            super.attachBaseContext(LocaleHelper.onAttach(newBase))    
        }
    
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)           
        }
    }
    
  2. Use Application attachBaseContext and onConfigurationChanged to set the locale language

    public class MyApplication extends Application {
        private static MyApplication application;
    
        @Override
        public void onCreate() {
            super.onCreate();
        }
    
        public static MyApplication getApplication() {
            return application;
        }
    
        /**
         * overide to change local sothat language can be chnaged from android device  nogaut and above
         */
        @Override
        protected void attachBaseContext(Context base) {
            super.attachBaseContext(LocaleHelper.INSTANCE.onAttach(base));
        }
    
        @Override
        public void onConfigurationChanged(Configuration newConfig) {
            setLanguageFromNewConfig(newConfig);
            super.onConfigurationChanged(newConfig);
        }
    
        /*** also handle chnage  language if  device language chnaged **/
        private void setLanguageFromNewConfig(Configuration newConfig){
            Prefs.putSaveLocaleLanguage(this,  selectedLocaleLanguage );
            LocaleHelper.INSTANCE.onAttach(this);
        }
    
  3. Use Locale Helper for handling language changes, this approach work on all device

    object LocaleHelper {
        private var defaultLanguage  :String = KycUtility.KYC_LANGUAGE.ENGLISH.languageCode
    
        fun onAttach(context: Context, defaultLanguage: String): Context {
            return setLocale(context, defaultLanguage)
        }
    
    
    
        fun setLocale(context: Context, language: String): Context {
            return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                updateResources(context, language)
            } else updateResourcesLegacy(context, language)
    
        }
    
    
        @TargetApi(Build.VERSION_CODES.N)
        private fun updateResources(context: Context, language: String): Context {
            val locale = Locale(language)
            Locale.setDefault(locale)
    
            val configuration = context.getResources().getConfiguration()
            configuration.setLocale(locale)
            configuration.setLayoutDirection(locale)
    
            return context.createConfigurationContext(configuration)
        }
    
        private fun updateResourcesLegacy(context: Context, language: String): Context {
            val locale = Locale(language)
            Locale.setDefault(locale)
    
            val resources = context.getResources()
    
            val configuration = resources.getConfiguration()
            configuration.locale = locale
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
                configuration.setLayoutDirection(locale)
            }
            resources.updateConfiguration(configuration, resources.getDisplayMetrics())
            return context
        }
    }
    

Most efficient way to remove special characters from string

It seems good to me. The only improvement I would make is to initialize the StringBuilder with the length of the string.

StringBuilder sb = new StringBuilder(str.Length);

Get json value from response

var results = {"id":"2231f87c-a62c-4c2c-8f5d-b76d11942301"}
console.log(results.id)
=>2231f87c-a62c-4c2c-8f5d-b76d11942301

results is now an object.

How can I escape square brackets in a LIKE clause?

If you would need to escape special characters like '_' (underscore), as it was in my case, and you are not willing/not able to define an ESCAPE clause, you may wish to enclose the special character with square brackets '[' and ']'.

This explains the meaning of the "weird" string '[[]' - it just embraces the '[' character with square brackets, effectively escaping it.

My use case was to specify the name of a stored procedure with underscores in it as a filter criteria for the Profiler. So I've put string '%name[_]of[_]a[_]stored[_]procedure%' in a TextData LIKE field and it gave me trace results I wanted to achieve.

Here is a good example from the documentation: LIKE (Transact-SQL) - Using Wildcard Characters As Literals

Test if string is a number in Ruby on Rails

no you're just using it wrong. your is_number? has an argument. you called it without the argument

you should be doing is_number?(mystring)

How to prevent rm from reporting that a file was not found?

The main use of -f is to force the removal of files that would not be removed using rm by itself (as a special case, it "removes" non-existent files, thus suppressing the error message).

You can also just redirect the error message using

$ rm file.txt 2> /dev/null

(or your operating system's equivalent). You can check the value of $? immediately after calling rm to see if a file was actually removed or not.

How to fix SSL certificate error when running Npm on Windows?

npm config set strict-ssl false

solved the issue for me. In this case both my agent and artifact depository are behind a private subnet on aws cloud

List comprehension vs. lambda + filter

Filter is just that. It filters out the elements of a list. You can see the definition mentions the same(in the official docs link I mentioned before). Whereas, list comprehension is something that produces a new list after acting upon something on the previous list.(Both filter and list comprehension creates new list and not perform operation in place of the older list. A new list here is something like a list with, say, an entirely new data type. Like converting integers to string ,etc)

In your example, it is better to use filter than list comprehension, as per the definition. However, if you want, say other_attribute from the list elements, in your example is to be retrieved as a new list, then you can use list comprehension.

return [item.other_attribute for item in my_list if item.attribute==value]

This is how I actually remember about filter and list comprehension. Remove a few things within a list and keep the other elements intact, use filter. Use some logic on your own at the elements and create a watered down list suitable for some purpose, use list comprehension.

Set today's date as default date in jQuery UI datepicker

try this:

$("#mydate").datepicker("setDate",'1d');

How can I get System variable value in Java?

Have you tried rebooting since you set the environment variable?

It appears that Windows keeps it's environment variable in some sort of cache, and rebooting is one method to refresh it. I'm not sure but there may be a different method, but if you are not going to be changing your variable value too often this may be good enough.

Print debugging info from stored procedure in MySQL

One workaround is just to use select without any other clauses.

http://lists.mysql.com/mysql/197901

R: Break for loop

Well, your code is not reproducible so we will never know for sure, but this is what help('break')says:

break breaks out of a for, while or repeat loop; control is transferred to the first statement outside the inner-most loop.

So yes, break only breaks the current loop. You can also see it in action with e.g.:

for (i in 1:10)
{
    for (j in 1:10)
    {
        for (k in 1:10)
        {
            cat(i," ",j," ",k,"\n")
            if (k ==5) break
        }   
    }
}

How to use multiple conditions (With AND) in IIF expressions in ssrs

You don't need an IIF() at all here. The comparisons return true or false anyway.

Also, since this row visibility is on a group row, make sure you use the same aggregate function on the fields as you use in the fields in the row. So if your group row shows sums, then you'd put this in the Hidden property.

=Sum(Fields!OpeningStock.Value) = 0 And
Sum(Fields!GrossDispatched.Value) = 0 And 
Sum(Fields!TransferOutToMW.Value) = 0 And
Sum(Fields!TransferOutToDW.Value) = 0 And
Sum(Fields!TransferOutToOW.Value) = 0 And
Sum(Fields!NetDispatched.Value) = 0 And
Sum(Fields!QtySold.Value) = 0 And
Sum(Fields!StockAdjustment.Value) = 0 And
Sum(Fields!ClosingStock.Value) = 0

But with the above version, if one record has value 1 and one has value -1 and all others are zero then sum is also zero and the row could be hidden. If that's not what you want you could write a more complex expression:

=Sum(
    IIF(
        Fields!OpeningStock.Value=0 AND
        Fields!GrossDispatched.Value=0 AND
        Fields!TransferOutToMW.Value=0 AND
        Fields!TransferOutToDW.Value=0 AND 
        Fields!TransferOutToOW.Value=0 AND
        Fields!NetDispatched.Value=0 AND
        Fields!QtySold.Value=0 AND
        Fields!StockAdjustment.Value=0 AND
        Fields!ClosingStock.Value=0,
        0,
        1
    )
) = 0

This is essentially a fancy way of counting the number of rows in which any field is not zero. If every field is zero for every row in the group then the expression returns true and the row is hidden.

Quickly create a large file on a Linux system

You can use "yes" command also. The syntax is fairly simple:

#yes >> myfile

Press "Ctrl + C" to stop this, else it will eat up all your space available.

To clean this file run:

#>myfile

will clean this file.

How to position a Bootstrap popover?

I've created a jQuery plugin that provides 4 additonal placements: topLeft, topRight, bottomLeft, bottomRight

You just include either the minified js or unminified js and have the matching css (minified vs unminified) in the same folder.

https://github.com/dkleehammer/bootstrap-popover-extra-placements

How to develop or migrate apps for iPhone 5 screen resolution?

If you have an app built for iPhone 4S or earlier, it'll run letterboxed on iPhone 5.

To adapt your app to the new taller screen, the first thing you do is to change the launch image to: [email protected]. Its size should be 1136x640 (HxW). Yep, having the default image in the new screen size is the key to let your app take the whole of new iPhone 5's screen.

(Note that the naming convention works only for the default image. Naming another image "[email protected]" will not cause it to be loaded in place of "[email protected]". If you need to load different images for different screen sizes, you'll have to do it programmatically.)

If you're very very lucky, that might be it... but in all likelihood, you'll have to take a few more steps.

  • Make sure, your Xibs/Views use auto-layout to resize themselves.
  • Use springs and struts to resize views.
  • If this is not good enough for your app, design your xib/storyboard for one specific screen size and reposition programmatically for the other.

In the extreme case (when none of the above suffices), design the two Xibs and load the appropriate one in the view controller.

To detect screen size:

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
{
    CGSize result = [[UIScreen mainScreen] bounds].size;
    if(result.height == 480)
    {
        // iPhone Classic
    }
    if(result.height == 568)
    {
        // iPhone 5
    }
}

How do I encode a JavaScript object as JSON?

All major browsers now include native JSON encoding/decoding.

// To encode an object (This produces a string)
var json_str = JSON.stringify(myobject); 

// To decode (This produces an object)
var obj = JSON.parse(json_str);

Note that only valid JSON data will be encoded. For example:

var obj = {'foo': 1, 'bar': (function (x) { return x; })}
JSON.stringify(obj) // --> "{\"foo\":1}"

Valid JSON types are: objects, strings, numbers, arrays, true, false, and null.

Some JSON resources:

How do I show a message in the foreach loop?

You are looking to see if a single value is in an array. Use in_array.

However note that case is important, as are any leading or trailing spaces. Use var_dump to find out the length of the strings too, and see if they fit.

Return multiple values in JavaScript?

You can do this from ECMAScript 6 onwards using arrays and "destructuring assignments". Note that these are not available in older Javascript versions (meaning — neither with ECMAScript 3rd nor 5th editions).

It allows you to assign to 1+ variables simultaneously:

var [x, y] = [1, 2];
x; // 1
y; // 2

// or

[x, y] = (function(){ return [3, 4]; })();
x; // 3
y; // 4

You can also use object destructuring combined with property value shorthand to name the return values in an object and pick out the ones you want:

let {baz, foo} = (function(){ return {foo: 3, bar: 500, baz: 40} })();
baz; // 40
foo; // 3

And by the way, don't be fooled by the fact that ECMAScript allows you to return 1, 2, .... What really happens there is not what might seem. An expression in return statement — 1, 2, 3 — is nothing but a comma operator applied to numeric literals (1 , 2, and 3) sequentially, which eventually evaluates to the value of its last expression — 3. That's why return 1, 2, 3 is functionally identical to nothing more but return 3.

return 1, 2, 3;
// becomes
return 2, 3;
// becomes
return 3;

Best way to deploy Visual Studio application that can run without installing

It is possible and is deceptively easy:

  1. "Publish" the application (to, say, some folder on drive C), either from menu Build or from the project's properties ? Publish. This will create an installer for a ClickOnce application.
  2. But instead of using the produced installer, find the produced files (the EXE file and the .config, .manifest, and .application files, along with any DLL files, etc.) - they are all in the same folder and typically in the bin\Debug folder below the project file (.csproj).
  3. Zip that folder (leave out any *.vhost.* files and the app.publish folder (they are not needed), and the .pdb files unless you foresee debugging directly on your user's system (for example, by remote control)), and provide it to the users.

An added advantage is that, as a ClickOnce application, it does not require administrative privileges to run (if your application follows the normal guidelines for which folders to use for application data, etc.).

As for .NET, you can check for the minimum required version of .NET being installed (or at all) in the application (most users will already have it installed) and present a dialog with a link to the download page on the Microsoft website (or point to one of your pages that could redirect to the Microsoft page - this makes it more robust if the Microsoft URL change). As it is a small utility, you could target .NET 2.0 to reduce the probability of a user to have to install .NET.

It works. We use this method during development and test to avoid having to constantly uninstall and install the application and still being quite close to how the final application will run.

How to get All input of POST in Laravel

It should be at least this:

public function login(Request $loginCredentials){
     $data = $loginCredentials->all();
     return $data['username'];
}

How can I add a new column and data to a datatable that already contains data?

Just keep going with your code - you're on the right track:

//call SQL helper class to get initial data 
DataTable dt = sql.ExecuteDataTable("sp_MyProc");

dt.Columns.Add("NewColumn", typeof(System.Int32));

foreach(DataRow row in dt.Rows)
{
    //need to set value to NewColumn column
    row["NewColumn"] = 0;   // or set it to some other value
}

// possibly save your Dataset here, after setting all the new values

What are the differences among grep, awk & sed?

Grep is useful if you want to quickly search for lines that match in a file. It can also return some other simple information like matching line numbers, match count, and file name lists.

Awk is an entire programming language built around reading CSV-style files, processing the records, and optionally printing out a result data set. It can do many things but it is not the easiest tool to use for simple tasks.

Sed is useful when you want to make changes to a file based on regular expressions. It allows you to easily match parts of lines, make modifications, and print out results. It's less expressive than awk but that lends it to somewhat easier use for simple tasks. It has many more complicated operators you can use (I think it's even turing complete), but in general you won't use those features.

Pylint, PyChecker or PyFlakes?

pep8 was recently added to PyPi.

  • pep8 - Python style guide checker
  • pep8 is a tool to check your Python code against some of the style conventions in PEP 8.

It is now super easy to check your code against pep8.

See http://pypi.python.org/pypi/pep8

Node.js: Gzip compression?

It's been a few good days with node, and you're right to say that you can't create a webserver without gzip.

There are quite a lot options given on the modules page on the Node.js Wiki. I tried out most of them, but this is the one which I'm finally using -

https://github.com/donnerjack13589/node.gzip

v1.0 is also out and it has been quite stable so far.

shell script to remove a file if it already exist

if [ $( ls <file> ) ]; then rm <file>; fi

Also, if you redirect your output with > instead of >> it will overwrite the previous file

Creating a node class in Java

Welcome to Java! This Nodes are like a blocks, they must be assembled to do amazing things! In this particular case, your nodes can represent a list, a linked list, You can see an example here:

public class ItemLinkedList {
    private ItemInfoNode head;
    private ItemInfoNode tail;
    private int size = 0;

    public int getSize() {
        return size;
    }

    public void addBack(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, null, tail);
            this.tail.next =node;
            this.tail = node;
        }
    }

    public void addFront(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, head, null);
            this.head.prev = node;
            this.head = node;
        }
    }

    public ItemInfo removeBack() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = tail.info;
            if (tail.prev != null) {
                tail.prev.next = null;
                tail = tail.prev;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public ItemInfo removeFront() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = head.info;
            if (head.next != null) {
                head.next.prev = null;
                head = head.next;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public class ItemInfoNode {

        private ItemInfoNode next;
        private ItemInfoNode prev;
        private ItemInfo info;

        public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev) {
            this.info = info;
            this.next = next;
            this.prev = prev;
        }

        public void setInfo(ItemInfo info) {
            this.info = info;
        }

        public void setNext(ItemInfoNode node) {
            next = node;
        }

        public void setPrev(ItemInfoNode node) {
            prev = node;
        }

        public ItemInfo getInfo() {
            return info;
        }

        public ItemInfoNode getNext() {
            return next;
        }

        public ItemInfoNode getPrev() {
            return prev;
        }
    }
}

EDIT:

Declare ItemInfo as this:

public class ItemInfo {
    private String name;
    private String rfdNumber;
    private double price;
    private String originalPosition;

    public ItemInfo(){
    }

    public ItemInfo(String name, String rfdNumber, double price, String originalPosition) {
        this.name = name;
        this.rfdNumber = rfdNumber;
        this.price = price;
        this.originalPosition = originalPosition;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRfdNumber() {
        return rfdNumber;
    }

    public void setRfdNumber(String rfdNumber) {
        this.rfdNumber = rfdNumber;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getOriginalPosition() {
        return originalPosition;
    }

    public void setOriginalPosition(String originalPosition) {
        this.originalPosition = originalPosition;
    }
}

Then, You can use your nodes inside the linked list like this:

public static void main(String[] args) {
    ItemLinkedList list = new ItemLinkedList();
    for (int i = 1; i <= 10; i++) {
        list.addBack(new ItemInfo("name-"+i, "rfd"+i, i, String.valueOf(i)));

    }
    while (list.size() > 0){
        System.out.println(list.removeFront().getName());
    }
}

Right way to split an std::string into a vector<string>

If the string has both spaces and commas you can use the string class function

found_index = myString.find_first_of(delims_str, begin_index) 

in a loop. Checking for != npos and inserting into a vector. If you prefer old school you can also use C's

strtok() 

method.

What is the mouse down selector in CSS?

I recently found out that :active:focus does the same thing in css as :active:hover if you need to override a custom css library, they might use both.

How to bind event listener for rendered elements in Angular 2?

HostListener should be the proper way to bind event into your component:

@Component({
  selector: 'your-element'
})

export class YourElement {
  @HostListener('click', ['$event']) onClick(event) {
     console.log('component is clicked');
     console.log(event);
  }
}

Bring element to front using CSS

Note: z-index only works on positioned elements (position:absolute, position:relative, or position:fixed). Use one of those.

What's a .sh file?

What is a file with extension .sh?

It is a Bourne shell script. They are used in many variations of UNIX-like operating systems. They have no "language" and are interpreted by your shell (interpreter of terminal commands) or if the first line is in the form

#!/path/to/interpreter

they will use that particular interpreter. Your file has the first line:

#!/bin/bash

and that means that it uses Bourne Again Shell, so called bash. It is for all practical purposes a replacement for good old sh.

Depending upon the interpreter you will have different language in which the file is written.

Keep in mind, that in UNIX world, it is not the extension of the file that determines what the file is (see How to execute a shell script).

If you come from the world of DOS/Windows, you will be familiar with files that have .bat or .cmd extensions (batch files). They are not similar in content, but are akin in design.

How to execute a shell script

Unlike some silly operating systems, *nix does not rely exclusively on extensions to determine what to do with a file. Permissions are also used. This means that if you attempt to run the shell script after downloading it, it will be the same as trying to "run" any text file. The ".sh" extension is there only for your convenience to recognize that file.

You will need to make the file executable. Let's assume that you have downloaded your file as file.sh, you can then run in your terminal:

chmod +x file.sh

chmod is a command for changing file's permissions, +x sets execute permissions (in this case for everybody) and finally you have your file name.

You can also do it in GUI. Most of the time you can right click on the file and select properties, in XUbuntu the permissions options look like this:

File permissions in XUbuntu

If you do not wish to change the permissions. You can also force the shell to run the command. In the terminal you can run:

bash file.sh

The shell should be the same as in the first line of your script.

How safe is it?

You may find it weird that you must perform another task manually in order to execute a file. But this is partially because of strong need for security.

Basically when you download and run a bash script, it is the same thing as somebody telling you "run all these commands in sequence on your computer, I promise that the results will be good and safe". Ask yourself if you trust the party that has supplied this file, ask yourself if you are sure that have downloaded the file from the same place as you thought, maybe even have a glance inside to see if something looks out of place (although that requires that you know something about *nix commands and bash programming).

Unfortunately apart from the warning above I cannot give a step-by-step description of what you should do to prevent evil things from happening with your computer; so just keep in mind that any time you get and run an executable file from someone you're actually saying, "Sure, you can use my computer to do something".

Difference between -XX:+UseParallelGC and -XX:+UseParNewGC

Parallel GC

  • XX:+UseParallelGC Use parallel garbage collection for scavenges. (Introduced in 1.4.1)
  • XX:+UseParallelOldGC Use parallel garbage collection for the full collections. Enabling this option automatically sets -XX:+UseParallelGC. (Introduced in 5.0 update 6.)

UseParNewGC

UseParNewGC A parallel version of the young generation copying collector is used with the concurrent collector (i.e. if -XX:+ UseConcMarkSweepGC is used on the command line then the flag UseParNewGC is also set to true if it is not otherwise explicitly set on the command line).

Perhaps the easiest way to understand was combinations of garbage collection algorithms made by Alexey Ragozin

_x000D_
_x000D_
<table border="1" style="width:100%">_x000D_
  <tr>_x000D_
    <td align="center">Young collector</td>_x000D_
    <td align="center">Old collector</td>_x000D_
    <td align="center">JVM option</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Serial (DefNew)</td>_x000D_
    <td>Serial Mark-Sweep-Compact</td>_x000D_
    <td>-XX:+UseSerialGC</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Parallel scavenge (PSYoungGen)</td>_x000D_
    <td>Serial Mark-Sweep-Compact (PSOldGen)</td>_x000D_
    <td>-XX:+UseParallelGC</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Parallel scavenge (PSYoungGen)</td>_x000D_
    <td>Parallel Mark-Sweep-Compact (ParOldGen)</td>_x000D_
    <td>-XX:+UseParallelOldGC</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Serial (DefNew)</td>_x000D_
    <td>Concurrent Mark Sweep</td>_x000D_
    <td>_x000D_
      <p>-XX:+UseConcMarkSweepGC</p>_x000D_
      <p>-XX:-UseParNewGC</p>_x000D_
    </td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Parallel (ParNew)</td>_x000D_
    <td>Concurrent Mark Sweep</td>_x000D_
    <td>_x000D_
      <p>-XX:+UseConcMarkSweepGC</p>_x000D_
      <p>-XX:+UseParNewGC</p>_x000D_
    </td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td colspan="2">G1</td>_x000D_
    <td>-XX:+UseG1GC</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Conclusion:

  1. Apply -XX:+UseParallelGC when you require parallel collection method over YOUNG generation ONLY, (but still) use serial-mark-sweep method as OLD generation collection
  2. Apply -XX:+UseParallelOldGC when you require parallel collection method over YOUNG generation (automatically sets -XX:+UseParallelGC) AND OLD generation collection
  3. Apply -XX:+UseParNewGC & -XX:+UseConcMarkSweepGC when you require parallel collection method over YOUNG generation AND require CMS method as your collection over OLD generation memory
  4. You can't apply -XX:+UseParallelGC or -XX:+UseParallelOldGC with -XX:+UseConcMarkSweepGC simultaneously, that's why your require -XX:+UseParNewGC to be paired with CMS otherwise use -XX:+UseSerialGC explicitly OR -XX:-UseParNewGC if you wish to use serial method against young generation

HttpClient does not exist in .net 4.0: what can I do?

Referring to the answers above, I am only adding this to help clarify things. It is possible to use HttpClient from .Net 4.0, and you have to install the package from here

However, the text is very confusion and contradicts itself.

This package is not supported in Visual Studio 2010, and is only required for projects targeting .NET Framework 4.5, Windows 8, or Windows Phone 8.1 when consuming a library that uses this package.

But underneath it states that these are the supported platforms.

Supported Platforms:

  • .NET Framework 4

  • Windows 8

  • Windows Phone 8.1

  • Windows Phone Silverlight 7.5

  • Silverlight 4

  • Portable Class Libraries

Ignore what it ways about targeting .Net 4.5. This is wrong. The package is all about using HttpClient in .Net 4.0. However, you may need to use VS2012 or higher. Not sure if it works in VS2010, but that may be worth testing.

What is the difference between `git merge` and `git merge --no-ff`?

Other answers indicate perfectly well that --no-ff results in a merge commit. This retains historical information about the feature branch which is useful since feature branches are regularly cleaned up and deleted.

This answer may provide context for when to use or not to use --no-ff.

Merging from feature into the main branch: use --no-ff

Worked example:

$ git checkout -b NewFeature
[work...work...work]
$ git commit -am  "New feature complete!"
$ git checkout main
$ git merge --no-ff NewFeature
$ git push origin main
$ git branch -d NewFeature

Merging changes from main into feature branch: leave off --no-ff

Worked example:

$ git checkout -b NewFeature
[work...work...work]
[New changes made for HotFix in the main branch! Lets get them...]
$ git commit -am  "New feature in progress"
$ git pull origin main
[shortcut for "git fetch origin main", "git merge origin main"]

receiving json and deserializing as List of object at spring mvc controller

I believe this will solve the issue

var z = '[{"name":"1","age":"2"},{"name":"1","age":"3"}]';
z = JSON.stringify(JSON.parse(z));
$.ajax({
    url: "/setTest",
    data: z,
    type: "POST",
    dataType:"json",
    contentType:'application/json'               
});

Get the Last Inserted Id Using Laravel Eloquent

public function store( UserStoreRequest $request ) {
    $input = $request->all();
    $user = User::create($input);
    $userId=$user->id 
}

How to differentiate single click event and double click event?

This answer is made obsolete through time, check @kyw's solution.

I created a solution inspired by the gist posted by @AdrienSchuler. Use this solution only when you want to bind a single click AND a double click to an element. Otherwise I recommend using the native click and dblclick listeners.

These are the differences:

  • Vanillajs, No dependencies
  • Don't wait on the setTimeout to handle the click or doubleclick handler
  • When double clicking it first fires the click handler, then the doubleclick handler

Javascript:

function makeDoubleClick(doubleClickCallback, singleClickCallback) {
    var clicks = 0, timeout;
    return function() {
        clicks++;
        if (clicks == 1) {
            singleClickCallback && singleClickCallback.apply(this, arguments);
            timeout = setTimeout(function() { clicks = 0; }, 400);
        } else {
            timeout && clearTimeout(timeout);
            doubleClickCallback && doubleClickCallback.apply(this, arguments);
            clicks = 0;
        }
    };
}

Usage:

var singleClick = function(){ console.log('single click') };
var doubleClick = function(){ console.log('double click') };
element.addEventListener('click', makeDoubleClick(doubleClick, singleClick));

Below is the usage in a jsfiddle, the jQuery button is the behavior of the accepted answer.

jsfiddle

tr:hover not working

tr:hover doesn't work in old browsers.

You can use jQuery for this:

.tr-hover
{  
  background-color:#fefefe;
}
$('.list1 tr').hover(function()
{
    $(this).addClass('tr-hover');
},function()
{
    $(this).removeClass('tr-hover');
});

How to add element in List while iterating in java?

Iterate through a copy of the list and add new elements to the original list.

for (String s : new ArrayList<String>(list))     
{
    list.add("u");
}

See How to make a copy of ArrayList object which is type of List?

How to force file download with PHP

try this:

header('Content-type: audio/mp3'); 
header('Content-disposition: attachment; 
filename=“'.$trackname'”');                             
readfile('folder name /'.$trackname);          
exit();

ASP.NET Setting width of DataBound column in GridView

I did a small demo for you. Demonstrating how to display long text.

In this example there is a column Name which may contain very long text. The boundField will display all content in a table cell and therefore the cell will expand as needed (because of the content)

The TemplateField will also be rendered as a cell BUT it contains a div which limits the width of any contet to eg 40px. So this column will have some kind of max-width!

    <asp:GridView ID="gvPersons" runat="server" AutoGenerateColumns="False" Width="100px">
        <Columns>
            <asp:BoundField HeaderText="ID" DataField="ID" />
            <asp:BoundField HeaderText="Name (long)" DataField="Name">
                <ItemStyle Width="40px"></ItemStyle>
            </asp:BoundField>
            <asp:TemplateField HeaderText="Name (short)">
                <ItemTemplate>
                    <div style="width: 40px; overflow: hidden; white-space: nowrap; text-overflow: ellipsis">
                        <%# Eval("Name") %>
                    </div>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

enter image description here

Here is my demo codeBehind

 public partial class gridViewLongText : System.Web.UI.Page
 {
     protected void Page_Load(object sender, EventArgs e)
     {
         #region init and bind data
         List<Person> list = new List<Person>();
         list.Add(new Person(1, "Sam"));
         list.Add(new Person(2, "Max"));
         list.Add(new Person(3, "Dave"));
         list.Add(new Person(4, "TabularasaVeryLongName"));
         gvPersons.DataSource = list;
         gvPersons.DataBind();
         #endregion
     }
 }

 public class Person
 {
     public int ID { get; set; }
     public string Name { get; set; }

     public Person(int _ID, string _Name)
     {
         ID = _ID;
         Name = _Name;
     }
 }

What is the meaning of "$" sign in JavaScript

Your snippet of code looks like it's referencing methods from one of the popular JavaScript libraries (jQuery, ProtoType, mooTools, and so on).

There's nothing mysterious about the use of $ in JavaScript. $ is simply a valid JavaScript identifier.

JavaScript allows upper and lower letters, numbers, and $ and _. The $ was intended to be used for machine-generated variables (such as $0001).

Prototype, jQuery, and most javascript libraries use the $ as the primary base object (or function). Most of them also have a way to relinquish the $ so that it can be used with another library that uses it. In that case you use jQuery instead of $. In fact, $ is just a shortcut for jQuery.

Is there a limit on how much JSON can hold?

JSON is similar to other data formats like XML - if you need to transmit more data, you just send more data. There's no inherent size limitation to the JSON request. Any limitation would be set by the server parsing the request. (For instance, ASP.NET has the "MaxJsonLength" property of the serializer.)

What are the differences between Visual Studio Code and Visual Studio?

For Unity3D users ...

  • VSCode is incredibly faster than VS. Files open instantly from Unity. VS is very slow. VSCode launches instantly. VS takes forever to launch.

  • VS can literally compile code, build apps and so on, it's a huge IDE like Unity itself or XCode. VSCode is indeed "just" a full-featured text editor. VSCode is NOT a compiler (far less a huge, build-everything system that can literally create apps and software of all types): VSCode is literally "just a text editor".

  • With VSCode, you DO need to install the "Visual Studio Code" package. (Not to be confused with the "Visual Studio" package.) (It seems to me that VS works fine without the VS package, but, with VS Code, you must install Unity's VSCode package.)

enter image description here

  • When you first download and install VSCode, simply open any C# file on your machine. It will instantly prompt you to install the needed C# package. This is harmless and easy.

  • Unfortunately VSCode generally has only one window! You cannot, really, easily drag files to separate windows. If this is important to you, you may need to go with VS.

  • The biggest problem with VS is that the overall concept of settings and preferences are absolutely horrible. In VS, it is all-but impossible to change the font, etc. In contrast, VSCode has FANTASTIC preferences - dead simple, never a problem.

  • As far as I can see, every single feature in VS which you use in Unity is present in VSCode. (So, code coloring, jump to definitions, it understands/autocompletes every single thing in Unity, it opens from Unity, double clicking something in the Unity console opens the file to that line, etc etc)

  • If you are used to VS. And you want to change to VSCode. It's always hard changing editors, they are so intimate, but it's pretty similar; you won't have a big heartache.

In short if you're a VS for Unity3D user,

and you're going to try VSCode...

  1. VSCode is on the order of 19 trillion times faster in every way. It will blow your mind.

  2. It does seem to have every feature.

  3. Basically VS is the world's biggest IDE and application building system: VSCode is just an editor. (Indeed, that's exactly what you want with Unity, since Unity itself is the IDE.)

  4. Don't forget to just click to install the relevant Unity package.

If I'm not mistaken, there is no reason whatsoever to use VS with Unity.

Unity is an IDE so you just need a text editor, and that is what VSCode is. VSCode is hugely better in both speed and preferences. The only possible problem - multiple-windows are a bit clunky in VSCode!

That horrible "double copy" problem in VS ... solved!

If you are using VS with Unity. There is an infuriating problem where often VS will try to open twice, that is you will end up with two or more copies of VS running. Nobody has ever been able to fix this or figure out what the hell causes it. Fortunately, this problem never happens with VSCode.

Installing VSCode on a Mac - unbelievably easy.

There are no installers, etc etc etc. On the download page, you download a zipped Mac app. Put it in the Applications folder and you're done.

Folding! (Mac/Windows keystrokes are different)

Bizarrely there's no menu entry / docu whatsoever for folding, but here are the keys:

https://stackoverflow.com/a/30077543/294884

Setting colors and so on in VSCode - the critical tips

Particularly for Mac users who may find the colors strange:

Priceless post #1:

https://stackoverflow.com/a/45640244/294884

Priceless post #2:

https://stackoverflow.com/a/63303503/294884

Meta files ...

To keep the "Explorer" list of files on the left tidy, in the Unity case:

enter image description here

ExecJS and could not find a JavaScript runtime

I started getting this problem when I started using rbenv with Ruby 1.9.3 where as my system ruby is 1.8.7. The gem is installed in both places but for some reason the rails script didn't pick it up. But adding the "execjs" and "therubyracer" to the Gemfile did the trick.

How do you format a Date/Time in TypeScript?

If you want the time out as well as the date you want Date.toLocaleString().

This was direct from my console:

> new Date().toLocaleString()
> "11/10/2016, 11:49:36 AM"

You can then input locale strings and format string to get the precise output you want.

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

Count words in a string method?

lambda, in which splitting and storing of the counted words is dispensed with
and only counting is done

String text = "counting w/o apostrophe's problems or consecutive   spaces";

int count = text.codePoints().boxed().collect(
    Collector.of(
        () -> new int[] {0, 0},
        (a, c) -> {
          if( ".,; \t".indexOf( c ) >= 0 )
            a[1] = 0;
          else if( a[1]++ == 0 ) a[0]++;
        }, (a, b) -> {a[0] += b[0]; return( a );},
        a -> a[0] ) );

gets: 7
works as a status machine that counts the transitions from spacing characters .,; \t to words

What does it mean when an HTTP request returns status code 0?

In addition to Lee's answer, you may find more information about the real cause by switching to synchronous requests, as you'll get also an exception :

function request(url) {
    var request = new XMLHttpRequest();
    try {
        request.open('GET', url, false);
        request.send(null);
    } catch (e) {
        console.log(url + ': ' + e);
    }
}

For example :

NetworkError: A network error occurred.

How to secure phpMyAdmin

Another solution is to use the config file without any settings. The first time you might have to include your mysql root login/password so it can install all its stuff but then remove it.

$cfg['Servers'][$i]['auth_type'] = 'cookie';

$cfg['Servers'][$i]['host'] = 'localhost';

$cfg['Servers'][$i]['connect_type'] = 'tcp';

$cfg['Servers'][$i]['compress'] = false;

$cfg['Servers'][$i]['extension'] = 'mysql';

Leaving it like that without any apache/lighhtpd aliases will just present to you a log in screen. enter image description here

You can log in with root but it is advised to create other users and only allow root for local access. Also remember to use string passwords, even if short but with a capital, and number of special character. for example !34sy2rmbr! aka "easy 2 remember"

-EDIT: A good password now a days is actually something like words that make no grammatical sense but you can remember because they funny. Or use keepass to generate strong randoms an have easy access to them

Does the join order matter in SQL?

For INNER joins, no, the order doesn't matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*.


For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much more complicated.

First, outer joins are not commutative, so a LEFT JOIN b is not the same as b LEFT JOIN a

Outer joins are not associative either, so in your examples which involve both (commutativity and associativity) properties:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id
  LEFT JOIN c
    ON c.ac_id = a.ac_id

is equivalent to:

a LEFT JOIN c 
    ON c.ac_id = a.ac_id
  LEFT JOIN b
    ON b.ab_id = a.ab_id

but:

a LEFT JOIN b 
    ON  b.ab_id = a.ab_id
  LEFT JOIN c
    ON  c.ac_id = a.ac_id
    AND c.bc_id = b.bc_id

is not equivalent to:

a LEFT JOIN c 
    ON  c.ac_id = a.ac_id
  LEFT JOIN b
    ON  b.ab_id = a.ab_id
    AND b.bc_id = c.bc_id

Another (hopefully simpler) associativity example. Think of this as (a LEFT JOIN b) LEFT JOIN c:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id          -- AB condition
 LEFT JOIN c
    ON c.bc_id = b.bc_id          -- BC condition

This is equivalent to a LEFT JOIN (b LEFT JOIN c):

a LEFT JOIN  
    b LEFT JOIN c
        ON c.bc_id = b.bc_id          -- BC condition
    ON b.ab_id = a.ab_id          -- AB condition

only because we have "nice" ON conditions. Both ON b.ab_id = a.ab_id and c.bc_id = b.bc_id are equality checks and do not involve NULL comparisons.

You can even have conditions with other operators or more complex ones like: ON a.x <= b.x or ON a.x = 7 or ON a.x LIKE b.x or ON (a.x, a.y) = (b.x, b.y) and the two queries would still be equivalent.

If however, any of these involved IS NULL or a function that is related to nulls like COALESCE(), for example if the condition was b.ab_id IS NULL, then the two queries would not be equivalent.

How to map a composite key with JPA and Hibernate?

To map a composite key, you can use the EmbeddedId or the IdClass annotations. I know this question is not strictly about JPA but the rules defined by the specification also applies. So here they are:

2.1.4 Primary Keys and Entity Identity

...

A composite primary key must correspond to either a single persistent field or property or to a set of such fields or properties as described below. A primary key class must be defined to represent a composite primary key. Composite primary keys typically arise when mapping from legacy databases when the database key is comprised of several columns. The EmbeddedId and IdClass annotations are used to denote composite primary keys. See sections 9.1.14 and 9.1.15.

...

The following rules apply for composite primary keys:

  • The primary key class must be public and must have a public no-arg constructor.
  • If property-based access is used, the properties of the primary key class must be public or protected.
  • The primary key class must be serializable.
  • The primary key class must define equals and hashCode methods. The semantics of value equality for these methods must be consistent with the database equality for the database types to which the key is mapped.
  • A composite primary key must either be represented and mapped as an embeddable class (see Section 9.1.14, “EmbeddedId Annotation”) or must be represented and mapped to multiple fields or properties of the entity class (see Section 9.1.15, “IdClass Annotation”).
  • If the composite primary key class is mapped to multiple fields or properties of the entity class, the names of primary key fields or properties in the primary key class and those of the entity class must correspond and their types must be the same.

With an IdClass

The class for the composite primary key could look like (could be a static inner class):

public class TimePK implements Serializable {
    protected Integer levelStation;
    protected Integer confPathID;

    public TimePK() {}

    public TimePK(Integer levelStation, Integer confPathID) {
        this.levelStation = levelStation;
        this.confPathID = confPathID;
    }
    // equals, hashCode
}

And the entity:

@Entity
@IdClass(TimePK.class)
class Time implements Serializable {
    @Id
    private Integer levelStation;
    @Id
    private Integer confPathID;

    private String src;
    private String dst;
    private Integer distance;
    private Integer price;

    // getters, setters
}

The IdClass annotation maps multiple fields to the table PK.

With EmbeddedId

The class for the composite primary key could look like (could be a static inner class):

@Embeddable
public class TimePK implements Serializable {
    protected Integer levelStation;
    protected Integer confPathID;

    public TimePK() {}

    public TimePK(Integer levelStation, Integer confPathID) {
        this.levelStation = levelStation;
        this.confPathID = confPathID;
    }
    // equals, hashCode
}

And the entity:

@Entity
class Time implements Serializable {
    @EmbeddedId
    private TimePK timePK;

    private String src;
    private String dst;
    private Integer distance;
    private Integer price;

    //...
}

The @EmbeddedId annotation maps a PK class to table PK.

Differences:

  • From the physical model point of view, there are no differences
  • @EmbeddedId somehow communicates more clearly that the key is a composite key and IMO makes sense when the combined pk is either a meaningful entity itself or it reused in your code.
  • @IdClass is useful to specify that some combination of fields is unique but these do not have a special meaning.

They also affect the way you write queries (making them more or less verbose):

  • with IdClass

    select t.levelStation from Time t
    
  • with EmbeddedId

    select t.timePK.levelStation from Time t
    

References

  • JPA 1.0 specification
    • Section 2.1.4 "Primary Keys and Entity Identity"
    • Section 9.1.14 "EmbeddedId Annotation"
    • Section 9.1.15 "IdClass Annotation"

How can I run a directive after the dom has finished rendering?

there is a ngcontentloaded event, I think you can use it

.directive('directiveExample', function(){
   return {
       restrict: 'A',
       link: function(scope, elem, attrs){

                $$window = $ $window


                init = function(){
                    contentHeight = elem.outerHeight()
                    //do the things
                }

                $$window.on('ngcontentloaded',init)

       }
   }
});

Hiding table data using <div style="display:none">

Give all the rows you want to hide a class name that you can use for hiding. Use javascript to add/remove this class from the different rows.

<table>
<tr><th>Test Table</th><tr>
<tr class="toHide"><td>123456789</td><tr>
<tr class="toHide"><td>123456789</td><tr>
<tr class="toHide"><td>123456789</td><tr>
</table>

CSS:

.toHide
{
 display: none;
}

JPA COUNT with composite primary key query not working

Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.

jQuery get values of checked checkboxes into array

I refactored your code a bit and believe I came with the solution for which you were looking. Basically instead of setting searchIDs to be the result of the .map() I just pushed the values into an array.

$("#merge_button").click(function(event){
  event.preventDefault();

  var searchIDs = [];

  $("#find-table input:checkbox:checked").map(function(){
    searchIDs.push($(this).val());
  });

  console.log(searchIDs);
});

I created a fiddle with the code running.

Best practices for circular shift (rotate) operations in C++

See also an earlier version of this answer on another rotate question with some more details about what asm gcc/clang produce for x86.

The most compiler-friendly way to express a rotate in C and C++ that avoids any Undefined Behaviour seems to be John Regehr's implementation. I've adapted it to rotate by the width of the type (using fixed-width types like uint32_t).

#include <stdint.h>   // for uint32_t
#include <limits.h>   // for CHAR_BIT
// #define NDEBUG
#include <assert.h>

static inline uint32_t rotl32 (uint32_t n, unsigned int c)
{
  const unsigned int mask = (CHAR_BIT*sizeof(n) - 1);  // assumes width is a power of 2.

  // assert ( (c<=mask) &&"rotate by type width or more");
  c &= mask;
  return (n<<c) | (n>>( (-c)&mask ));
}

static inline uint32_t rotr32 (uint32_t n, unsigned int c)
{
  const unsigned int mask = (CHAR_BIT*sizeof(n) - 1);

  // assert ( (c<=mask) &&"rotate by type width or more");
  c &= mask;
  return (n>>c) | (n<<( (-c)&mask ));
}

Works for any unsigned integer type, not just uint32_t, so you could make versions for other sizes.

See also a C++11 template version with lots of safety checks (including a static_assert that the type width is a power of 2), which isn't the case on some 24-bit DSPs or 36-bit mainframes, for example.

I'd recommend only using the template as a back-end for wrappers with names that include the rotate width explicitly. Integer-promotion rules mean that rotl_template(u16 & 0x11UL, 7) would do a 32 or 64-bit rotate, not 16 (depending on the width of unsigned long). Even uint16_t & uint16_t is promoted to signed int by C++'s integer-promotion rules, except on platforms where int is no wider than uint16_t.


On x86, this version inlines to a single rol r32, cl (or rol r32, imm8) with compilers that grok it, because the compiler knows that x86 rotate and shift instructions mask the shift-count the same way the C source does.

Compiler support for this UB-avoiding idiom on x86, for uint32_t x and unsigned int n for variable-count shifts:

  • clang: recognized for variable-count rotates since clang3.5, multiple shifts+or insns before that.
  • gcc: recognized for variable-count rotates since gcc4.9, multiple shifts+or insns before that. gcc5 and later optimize away the branch and mask in the wikipedia version, too, using just a ror or rol instruction for variable counts.
  • icc: supported for variable-count rotates since ICC13 or earlier. Constant-count rotates use shld edi,edi,7 which is slower and takes more bytes than rol edi,7 on some CPUs (especially AMD, but also some Intel), when BMI2 isn't available for rorx eax,edi,25 to save a MOV.
  • MSVC: x86-64 CL19: Only recognized for constant-count rotates. (The wikipedia idiom is recognized, but the branch and AND aren't optimized away). Use the _rotl / _rotr intrinsics from <intrin.h> on x86 (including x86-64).

gcc for ARM uses an and r1, r1, #31 for variable-count rotates, but still does the actual rotate with a single instruction: ror r0, r0, r1. So gcc doesn't realize that rotate-counts are inherently modular. As the ARM docs say, "ROR with shift length, n, more than 32 is the same as ROR with shift length n-32". I think gcc gets confused here because left/right shifts on ARM saturate the count, so a shift by 32 or more will clear the register. (Unlike x86, where shifts mask the count the same as rotates). It probably decides it needs an AND instruction before recognizing the rotate idiom, because of how non-circular shifts work on that target.

Current x86 compilers still use an extra instruction to mask a variable count for 8 and 16-bit rotates, probably for the same reason they don't avoid the AND on ARM. This is a missed optimization, because performance doesn't depend on the rotate count on any x86-64 CPU. (Masking of counts was introduced with 286 for performance reasons because it handled shifts iteratively, not with constant-latency like modern CPUs.)

BTW, prefer rotate-right for variable-count rotates, to avoid making the compiler do 32-n to implement a left rotate on architectures like ARM and MIPS that only provide a rotate-right. (This optimizes away with compile-time-constant counts.)

Fun fact: ARM doesn't really have dedicated shift/rotate instructions, it's just MOV with the source operand going through the barrel-shifter in ROR mode: mov r0, r0, ror r1. So a rotate can fold into a register-source operand for an EOR instruction or something.


Make sure you use unsigned types for n and the return value, or else it won't be a rotate. (gcc for x86 targets does arithmetic right shifts, shifting in copies of the sign-bit rather than zeroes, leading to a problem when you OR the two shifted values together. Right-shifts of negative signed integers is implementation-defined behaviour in C.)

Also, make sure the shift count is an unsigned type, because (-n)&31 with a signed type could be one's complement or sign/magnitude, and not the same as the modular 2^n you get with unsigned or two's complement. (See comments on Regehr's blog post). unsigned int does well on every compiler I've looked at, for every width of x. Some other types actually defeat the idiom-recognition for some compilers, so don't just use the same type as x.


Some compilers provide intrinsics for rotates, which is far better than inline-asm if the portable version doesn't generate good code on the compiler you're targeting. There aren't cross-platform intrinsics for any compilers that I know of. These are some of the x86 options:

  • Intel documents that <immintrin.h> provides _rotl and _rotl64 intrinsics, and same for right shift. MSVC requires <intrin.h>, while gcc require <x86intrin.h>. An #ifdef takes care of gcc vs. icc, but clang doesn't seem to provide them anywhere, except in MSVC compatibility mode with -fms-extensions -fms-compatibility -fms-compatibility-version=17.00. And the asm it emits for them sucks (extra masking and a CMOV).
  • MSVC: _rotr8 and _rotr16.
  • gcc and icc (not clang): <x86intrin.h> also provides __rolb/__rorb for 8-bit rotate left/right, __rolw/__rorw (16-bit), __rold/__rord (32-bit), __rolq/__rorq (64-bit, only defined for 64-bit targets). For narrow rotates, the implementation uses __builtin_ia32_rolhi or ...qi, but the 32 and 64-bit rotates are defined using shift/or (with no protection against UB, because the code in ia32intrin.h only has to work on gcc for x86). GNU C appears not to have any cross-platform __builtin_rotate functions the way it does for __builtin_popcount (which expands to whatever's optimal on the target platform, even if it's not a single instruction). Most of the time you get good code from idiom-recognition.

// For real use, probably use a rotate intrinsic for MSVC, or this idiom for other compilers.  This pattern of #ifdefs may be helpful
#if defined(__x86_64__) || defined(__i386__)

#ifdef _MSC_VER
#include <intrin.h>
#else
#include <x86intrin.h>  // Not just <immintrin.h> for compilers other than icc
#endif

uint32_t rotl32_x86_intrinsic(rotwidth_t x, unsigned n) {
  //return __builtin_ia32_rorhi(x, 7);  // 16-bit rotate, GNU C
  return _rotl(x, n);  // gcc, icc, msvc.  Intel-defined.
  //return __rold(x, n);  // gcc, icc.
  // can't find anything for clang
}
#endif

Presumably some non-x86 compilers have intrinsics, too, but let's not expand this community-wiki answer to include them all. (Maybe do that in the existing answer about intrinsics).


(The old version of this answer suggested MSVC-specific inline asm (which only works for 32bit x86 code), or http://www.devx.com/tips/Tip/14043 for a C version. The comments are replying to that.)

Inline asm defeats many optimizations, especially MSVC-style because it forces inputs to be stored/reloaded. A carefully-written GNU C inline-asm rotate would allow the count to be an immediate operand for compile-time-constant shift counts, but it still couldn't optimize away entirely if the value to be shifted is also a compile-time constant after inlining. https://gcc.gnu.org/wiki/DontUseInlineAsm.

How can I add to a List's first position?

 myList.Insert(0, item);

         

What does "O(1) access time" mean?

According to my perspective,

O(1) means time to execute one operation or instruction at a time is one, in time complexity analysis of algorithm for best case.

Reference requirements.txt for the install_requires kwarg in setuptools setup.py file

Install the current package in Travis. This avoids the use of a requirements.txt file. For example:

language: python
python:
  - "2.7"
  - "2.6"
install:
  - pip install -q -e .
script:
  - python runtests.py

Where to find extensions installed folder for Google Chrome on Mac?

The default locations of Chrome's profile directory are defined at http://www.chromium.org/user-experience/user-data-directory. For Chrome on Mac, it's

~/Library/Application\ Support/Google/Chrome/Default

The actual location can be different, by setting the --user-data-dir=path/to/directory flag.
If only one user is registered in Chrome, look in the Default/Extensions subdirectory. Otherwise, look in the <profile user name>/Extensions directory.

If that didn't help, you can always do a custom search.

  1. Go to chrome://extensions/, and find out the ID of an extension (32 lowercase letters) (if not done already, activate "Developer mode" first).

  2. Open the terminal, cd to the directory which is most likely a parent of your Chrome profile (if unsure, try ~ then /).

  3. Run find . -type d -iname "<EXTENSION ID HERE>", for example:

    find . -type d -iname jifpbeccnghkjeaalbbjmodiffmgedin
    

    Result:

    ./Library/Application Support/Google/Chrome/Default/Extensions/jifpbeccnghkjeaalbbjmodiffmgedin

Copy output of a JavaScript variable to the clipboard

I managed to copy text to the clipboard (without showing any text boxes) by adding a hidden input element to body, i.e.:

_x000D_
_x000D_
 function copy(txt){_x000D_
  var cb = document.getElementById("cb");_x000D_
  cb.value = txt;_x000D_
  cb.style.display='block';_x000D_
  cb.select();_x000D_
  document.execCommand('copy');_x000D_
  cb.style.display='none';_x000D_
 }
_x000D_
<button onclick="copy('Hello Clipboard!')"> copy </button>_x000D_
<input id="cb" type="text" hidden>
_x000D_
_x000D_
_x000D_

How to clear Route Caching on server: Laravel 5.2.37

you can define a route in web.php

Route::get('/clear/route', 'ConfigController@clearRoute');

and make ConfigController.php like this

   class ConfigController extends Controller
{
    public function clearRoute()
    {
        \Artisan::call('route:clear');
    }
}

and go to that route on server example http://your-domain/clear/route

Detect if value is number in MySQL

This should work in most cases.

SELECT * FROM myTable WHERE concat('',col1 * 1) = col1

It doesn't work for non-standard numbers like

  • 1e4
  • 1.2e5
  • 123. (trailing decimal)

How to use sed to extract substring

sed 's/[^"]*"\([^"]*\).*/\1/'

does the job.

explanation of the part inside ' '

  • s - tells sed to substitute
  • / - start of regex string to search for
  • [^"]* - any character that is not ", any number of times. (matching parameter name=)
  • " - just a ".
  • ([^"]*) - anything inside () will be saved for reference to use later. The \ are there so the brackets are not considered as characters to search for. [^"]* means the same as above. (matching RemoteHost for example)
  • .* - any character, any number of times. (matching " access="readWrite"> /parameter)
  • / - end of the search regex, and start of the substitute string.
  • \1 - reference to that string we found in the brackets above.
  • / end of the substitute string.

basically s/search for this/replace with this/ but we're telling him to replace the whole line with just a piece of it we found earlier.

Generate GUID in MySQL for existing Data?

I faced mostly the same issue. Im my case uuid is stored as BINARY(16) and has NOT NULL UNIQUE constraints. And i faced with the issue when the same UUID was generated for every row, and UNIQUE constraint does not allow this. So this query does not work:

UNHEX(REPLACE(uuid(), '-', ''))

But for me it worked, when i used such a query with nested inner select:

UNHEX(REPLACE((SELECT uuid()), '-', ''))

Then is produced unique result for every entry.