Programs & Examples On #Magic string

A magic string is an input that a programmer believes will never come externally and which activates otherwise hidden functionality. A user of this program would likely provide input that gives an expected response in most situations. However, if the user does in fact innocently provide the pre-defined input, invoking the internal functionality, the program response is often quite unexpected to the user (thus appearing 'magical').

ORA-00054: resource busy and acquire with NOWAIT specified

Depending on your situation, the table being locked may just be part of a normal operation & you don't want to just kill the blocking transaction. What you want to do is have your statement wait for the other resource. Oracle 11g has DDL timeouts which can be set to deal with this.

If you're dealing with 10g then you have to get more creative and write some PL/SQL to handle the re-try. Look at Getting around ORA-00054 in Oracle 10g This re-runs your statement when a resource_busy exception occurs.

Difference between 2 dates in SQLite

The SQLite documentation is a great reference and the DateAndTimeFunctions page is a good one to bookmark.

It's also helpful to remember that it's pretty easy to play with queries with the sqlite command line utility:

sqlite> select julianday(datetime('now'));
2454788.09219907
sqlite> select datetime(julianday(datetime('now')));
2008-11-17 14:13:55

How do I restart my C# WinForm Application?

I use the following and it does exactly what you are looking for:

ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
UpdateCheckInfo info = null;
info = ad.CheckForDetailedUpdate();
if (info.IsUpdateRequired)
{
    ad.UpdateAsync(); // I like the update dialog
    MessageBox.Show("Application was upgraded and will now restart.");
    Environment.Exit(0);
}

How to Cast Objects in PHP

Without using inheritance (as mentioned by author), it seems like you are looking for a solution that can transform one class to another with preassumption of the developer knows and understand the similarity of 2 classes.

There's no existing solution for transforming between objects. What you can try out are:

How to read existing text files without defining path

If your application is a web service, Directory.CurrentDirectory doesn't work.

Use System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "yourFileName.txt")) instead.

How to get the next auto-increment id in mysql

I suggest to rethink what you are doing. I never experienced one single use case where that special knowledge is required. The next id is a very special implementation detail and I wouldn't count on getting it is ACID safe.

Make one simple transaction which updates your inserted row with the last id:

BEGIN;

INSERT INTO payments (date, item, method)
     VALUES (NOW(), '1 Month', 'paypal');

UPDATE payments SET payment_code = CONCAT("sahf4d2fdd45", LAST_INSERT_ID())
     WHERE id = LAST_INSERT_ID();

COMMIT;

PHP Undefined Index

I don't see php file, but that could be that -
replace in your php file:

$query_age = $_GET['query_age'];

with:

$query_age = (isset($_GET['query_age']) ? $_GET['query_age'] : null);

Most probably, at first time you running your script without ?query_age=[something] and $_GET has no key like query_age.

How to avoid java.util.ConcurrentModificationException when iterating through and removing elements from an ArrayList

Instead of using For each loop, use normal for loop. for example,the below code removes all the element in the array list without giving java.util.ConcurrentModificationException. You can modify the condition in the loop according to your use case.

for(int i=0; i<abc.size(); i++)  {
       e.remove(i);
 }

Appending a list to a list of lists in R

By putting an assignment of list on a variable first

myVar <- list()

it opens the possibility of hiearchial assignments by

myVar[[1]] <- list()
myVar[[2]] <- list()

and so on... so now it's possible to do

myVar[[1]][[1]] <- c(...)
myVar[[1]][[2]] <- c(...)

or

myVar[[1]][['subVar']] <- c(...)

and so on

it is also possible to assign directly names (instead of $)

myVar[['nameofsubvar]] <- list()

and then

myVar[['nameofsubvar]][['nameofsubsubvar']] <- c('...')

important to remember is to always use double brackets to make the system work

then to get information is simple

myVar$nameofsubvar$nameofsubsubvar

and so on...

example:

a <-list()
a[['test']] <-list()
a[['test']][['subtest']] <- c(1,2,3)
a
$test
$test$subtest
[1] 1 2 3


a[['test']][['sub2test']] <- c(3,4,5)
a
$test
$test$subtest
[1] 1 2 3

$test$sub2test
[1] 3 4 5

a nice feature of the R language in it's hiearchial definition...

I used it for a complex implementation (with more than two levels) and it works!

Passing Javascript variable to <a href >

Alternatively you could just use a document.write:

<script type="text\javascript">
var loc = "http://";
document.write('<a href="' + loc + '">Link text</a>');
</script>

How to use wait and notify in Java without IllegalMonitorStateException?

To be able to call notify() you need to synchronize on the same object.

synchronized (someObject) {
    someObject.wait();
}

/* different thread / object */
synchronized (someObject) {
    someObject.notify();
}

if statement checks for null but still throws a NullPointerException

The edit shows exactly the difference between code that works and code that doesn't.

This check always evaluates both of the conditions, throwing an exception if str is null:

 if (str == null | str.length() == 0) {

Whereas this (using || instead of |) is short-circuiting - if the first condition evaluates to true, the second is not evaluated.

See section 15.24 of the JLS for a description of ||, and section 15.22.2 for binary |. The intro to section 15.24 is the important bit though:

The conditional-or operator || operator is like | (§15.22.2), but evaluates its right-hand operand only if the value of its left-hand operand is false.

How to call a function within class?

That doesn't work because distToPoint is inside your class, so you need to prefix it with the classname if you want to refer to it, like this: classname.distToPoint(self, p). You shouldn't do it like that, though. A better way to do it is to refer to the method directly through the class instance (which is the first argument of a class method), like so: self.distToPoint(p).

How to convert POJO to JSON and vice versa?

Take a look at https://www.json.org

[edited] Imagine that you have a simple Java class like this:

public class Person {

    private String name;
    private Integer age;

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

    public Integer getAge() { return this.age; }
    public void setAge( Integer age ) { this.age = age; }

}

So, to transform it to a JSon object, it's very simple. Like this:

import org.json.JSONObject;

public class JsonTest {

    public static void main( String[] args ) {
        Person person = new Person();
        person.setName( "Person Name" );
        person.setAge( 333 );

        JSONObject jsonObj = new JSONObject( person );
        System.out.println( jsonObj );
    }

}

Hope it helps.

[edited] Here there is other example, in this case using Jackson: https://brunozambiazi.wordpress.com/2015/08/15/working-with-json-in-java/

Maven:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.6.1</version>
</dependency>

And a link (below) to find the latest/greatest version:

https://search.maven.org/classic/#search%7Cga%7C1%7Cg%3A%22com.fasterxml.jackson.core%22%20AND%20a%3A%22jackson-databind%22

Graphical user interface Tutorial in C

My favourite UI tutorials all come from zetcode.com:

These are tutorials I'd consider to be "starting tutorials". The example tutorial gets you up and going, but doesn't show you anything too advanced or give much explanation. Still, often, I find the big problem is "how do I start?" and these have always proved useful to me.

Going to a specific line number using Less in Unix

To open at a specific line straight from the command line, use:

less +320123 filename

If you want to see the line numbers too:

less +320123 -N filename

You can also choose to display a specific line of the file at a specific line of the terminal, for when you need a few lines of context. For example, this will open the file with line 320123 on the 10th line of the terminal:

less +320123 -j 10 filename

*.h or *.hpp for your class definitions

You can call your includes whatever you like.

Just need to specify that full name in the #include.

I suggest that if you work with C to use .h and when with C++ to use .hpp.

It is in the end just a convention.

What is the correct syntax of ng-include?

This worked for me:

ng-include src="'views/templates/drivingskills.html'"

complete div:

<div id="drivivgskills" ng-controller="DrivingSkillsCtrl" ng-view ng-include src="'views/templates/drivingskills.html'" ></div>

Best Practice to Organize Javascript Library & CSS Folder Structure

 root/
   assets/
      lib/-------------------------libraries--------------------
          bootstrap/--------------Libraries can have js/css/images------------
              css/
              js/
              images/  
          jquery/
              js/
          font-awesome/
              css/
              images/
     common/--------------------common section will have application level resources             
          css/
          js/
          img/

 index.html

This is how I organized my application's static resources.

Initializing a member array in constructor initializer

  1. How can I do what I want to do (that is, initialize an array in a constructor (not assigning elements in the body)). Is it even possible?

Yes. It's using a struct that contains an array. You say you already know about that, but then I don't understand the question. That way, you do initialize an array in the constructor, without assignments in the body. This is what boost::array does.

Does the C++03 standard say anything special about initializing aggregates (including arrays) in ctor initializers? Or the invalidness of the above code is a corollary of some other rules?

A mem-initializer uses direct initialization. And the rules of clause 8 forbid this kind of thing. I'm not exactly sure about the following case, but some compilers do allow it.

struct A {
  char foo[6];
  A():foo("hello") { } /* valid? */
};

See this GCC PR for further details.

Do C++0x initializer lists solve the problem?

Yes, they do. However your syntax is invalid, I think. You have to use braces directly to fire off list initialization

struct A {
  int foo[3];
  A():foo{1, 2, 3} { }
  A():foo({1, 2, 3}) { } /* invalid */
};

fatal: The current branch master has no upstream branch

You need to configure the remote first, then push.

git remote add origin url-to-your-repo

Actual Instructions

MySQL query to select events between start/end date

If I understood correctly you are trying to use a single query, i think you can just merge your date search toghter in WHERE clauses

SELECT id 
FROM events 
WHERE start BETWEEN '2013-06-13' AND '2013-07-22' 
AND end BETWEEN '2013-06-13' AND '2013-07-22'

or even more simply you can just use both column to set search time filter

SELECT id 
FROM events 
WHERE start >= '2013-07-22' AND end <= '2013-06-13'

How to send 100,000 emails weekly?

Here is what I did recently in PHP on one of my bigger systems:

  1. User inputs newsletter text and selects the recipients (which generates a query to retrieve the email addresses for later).

  2. Add the newsletter text and recipients query to a row in mysql table called *email_queue*

    • (The table email_queue has the columns "to" "subject" "body" "priority")
  3. I created another script, which runs every minute as a cron job. It uses the SwiftMailer class. This script simply:

    • during business hours, sends all email with priority == 0

    • after hours, send other emails by priority

Depending on the hosts settings, I can now have it throttle using standard swiftmailers plugins like antiflood and throttle...

$mailer->registerPlugin(new Swift_Plugins_AntiFloodPlugin(50, 30));

and

$mailer->registerPlugin(new Swift_Plugins_ThrottlerPlugin( 100, Swift_Plugins_ThrottlerPlugin::MESSAGES_PER_MINUTE ));

etc, etc..

I have expanded it way beyond this pseudocode, with attachments, and many other configurable settings, but it works very well as long as your server is setup correctly to send email. (Probably wont work on shared hosting, but in theory it should...) Swiftmailer even has a setting

$message->setReturnPath

Which I now use to track bounces...

Happy Trails! (Happy Emails?)

`IF` statement with 3 possible answers each based on 3 different ranges

=IF(X2>=85,0.559,IF(X2>=80,0.327,IF(X2>=75,0.255,-1)))

Explanation:

=IF(X2>=85,                  'If the value is in the highest bracket
      0.559,                 'Use the appropriate number
      IF(X2>=80,             'Otherwise, if the number is in the next highest bracket
           0.327,            'Use the appropriate number
           IF(X2>=75,        'Otherwise, if the number is in the next highest bracket
              0.255,         'Use the appropriate number
              -1             'Otherwise, we're not in any of the ranges (Error)
             )
        )
   )

Find commit by hash SHA in Git

There are two ways to do this.

1. providing the SHA of the commit you want to see to git log

git log -p a2c25061

Where -p is short for patch

2. use git show

git show a2c25061

The output for both commands will be:

  • the commit
  • the author
  • the date
  • the commit message
  • the patch information

Compare DATETIME and DATE ignoring time portion

Use the CAST to the new DATE data type in SQL Server 2008 to compare just the date portion:

IF CAST(DateField1 AS DATE) = CAST(DateField2 AS DATE)

Benefits of inline functions in C++?

Conclusion from another discussion here:

Are there any drawbacks with inline functions?

Apparently, There is nothing wrong with using inline functions.

But it is worth noting the following points!

  • Overuse of inlining can actually make programs slower. Depending on a function's size, inlining it can cause the code size to increase or decrease. Inlining a very small accessor function will usually decrease code size while inlining a very large function can dramatically increase code size. On modern processors smaller code usually runs faster due to better use of the instruction cache. - Google Guidelines

  • The speed benefits of inline functions tend to diminish as the function grows in size. At some point the overhead of the function call becomes small compared to the execution of the function body, and the benefit is lost - Source

  • There are few situations where an inline function may not work:

    • For a function returning values; if a return statement exists.
    • For a function not returning any values; if a loop, switch or goto statement exists.
    • If a function is recursive. -Source
  • The __inline keyword causes a function to be inlined only if you specify the optimize option. If optimize is specified, whether or not __inline is honored depends on the setting of the inline optimizer option. By default, the inline option is in effect whenever the optimizer is run. If you specify optimize , you must also specify the noinline option if you want the __inline keyword to be ignored. -Source

Converting from byte to int in java

I thought it would be:

byte b = (byte)255;
int i = b &255;

How to use glOrtho() in OpenGL?

glOrtho describes a transformation that produces a parallel projection. The current matrix (see glMatrixMode) is multiplied by this matrix and the result replaces the current matrix, as if glMultMatrix were called with the following matrix as its argument:

OpenGL documentation (my bold)

The numbers define the locations of the clipping planes (left, right, bottom, top, near and far).

The "normal" projection is a perspective projection that provides the illusion of depth. Wikipedia defines a parallel projection as:

Parallel projections have lines of projection that are parallel both in reality and in the projection plane.

Parallel projection corresponds to a perspective projection with a hypothetical viewpoint—e.g., one where the camera lies an infinite distance away from the object and has an infinite focal length, or "zoom".

How to Merge Two Eloquent Collections?

All do not work for me on eloquent collections, laravel eloquent collections use the key from the items I think which causes merging issues, you need to get the first collection back as an array, put that into a fresh collection and then push the others into the new collection;

public function getFixturesAttribute()
{
    $fixtures = collect( $this->homeFixtures->all() );
    $this->awayFixtures->each( function( $fixture ) use ( $fixtures ) {
        $fixtures->push( $fixture );
    });
    return $fixtures;
}

Test if a property is available on a dynamic variable

Well, I faced a similar problem but on unit tests.

Using SharpTestsEx you can check if a property existis. I use this testing my controllers, because since the JSON object is dynamic, someone can change the name and forget to change it in the javascript or something, so testing for all properties when writing the controller should increase my safety.

Example:

dynamic testedObject = new ExpandoObject();
testedObject.MyName = "I am a testing object";

Now, using SharTestsEx:

Executing.This(delegate {var unused = testedObject.MyName; }).Should().NotThrow();
Executing.This(delegate {var unused = testedObject.NotExistingProperty; }).Should().Throw();

Using this, i test all existing properties using "Should().NotThrow()".

It's probably out of topic, but can be usefull for someone.

Char to int conversion in C

int i = c - '0';

You should be aware that this doesn't perform any validation against the character - for example, if the character was 'a' then you would get 91 - 48 = 49. Especially if you are dealing with user or network input, you should probably perform validation to avoid bad behavior in your program. Just check the range:

if ('0' <= c &&  c <= '9') {
    i = c - '0';
} else {
    /* handle error */
}

Note that if you want your conversion to handle hex digits you can check the range and perform the appropriate calculation.

if ('0' <= c && c <= '9') {
    i = c - '0';
} else if ('a' <= c && c <= 'f') {
    i = 10 + c - 'a';
} else if ('A' <= c && c <= 'F') {
    i = 10 + c - 'A';
} else {
    /* handle error */
}

That will convert a single hex character, upper or lowercase independent, into an integer.

How to get unique values in an array

If you want to leave the original array intact,

you need a second array to contain the uniqe elements of the first-

Most browsers have Array.prototype.filter:

var unique= array1.filter(function(itm, i){
    return array1.indexOf(itm)== i; 
    // returns true for only the first instance of itm
});


//if you need a 'shim':
Array.prototype.filter= Array.prototype.filter || function(fun, scope){
    var T= this, A= [], i= 0, itm, L= T.length;
    if(typeof fun== 'function'){
        while(i<L){
            if(i in T){
                itm= T[i];
                if(fun.call(scope, itm, i, T)) A[A.length]= itm;
            }
            ++i;
        }
    }
    return A;
}
 Array.prototype.indexOf= Array.prototype.indexOf || function(what, i){
        if(!i || typeof i!= 'number') i= 0;
        var L= this.length;
        while(i<L){
            if(this[i]=== what) return i;
            ++i;
        }
        return -1;
    }

SSIS Convert Between Unicode and Non-Unicode Error

  1. First, add a data conversion block into your data flow diagram.

  2. Open the data conversion block and tick the column for which the error is showing. Below change its data type to unicode string(DT_WSTR) or whatever datatype is expected and save.

  3. Go to the destination block. Go to mapping in it and map the newly created element to its corresponding address and save.

  4. Right click your project in the solution explorer.select properties. Select configuration properties and select debugging in it. In this, set the Run64BitRunTime option to false (as excel does not handle the 64 bit application very well).

Swift presentViewController

I had a similar issue but in my case, the solution was to dispatch the action as an async task in the main queue

DispatchQueue.main.async {
    let vc = self.storyboard?.instantiateViewController(withIdentifier: myVCID) as! myVCName
    self.present(vc, animated: true, completion: nil)
}

How to detect the screen resolution with JavaScript?

function getScreenWidth()
{
   var de = document.body.parentNode;
   var db = document.body;
   if(window.opera)return db.clientWidth;
   if (document.compatMode=='CSS1Compat') return de.clientWidth;
   else return db.clientWidth;
}

JQuery find first parent element with specific class prefix

Jquery later allowed you to to find the parents with the .parents() method.

Hence I recommend using:

var $div = $('#divid').parents('div[class^="div-a"]');

This gives all parent nodes matching the selector. To get the first parent matching the selector use:

var $div = $('#divid').parents('div[class^="div-a"]').eq(0);

For other such DOM traversal queries, check out the documentation on traversing the DOM.

How to monitor SQL Server table changes by using c#?

Another, very simple way of monitoring tables is table versioning. The system is proven working in constructions such as DNS synchronization. To make it work you create a table containing table names and table versions as decimal or bigint.In each table that you need monitored, create trigger on insert, update and delete that will increment appropriate table version in versioning table when executed. If you expect any of the monitored tables to be altered often, you need to provision for version reusing. Finally, in your application, every time you query monitored table, you also query its version and store it. When you go to alter the monitored table from your app, you first query its current version and process the change only if the version is unchanged. You can have stored proc on sql server do that work for you. This is extremely simple but proven solid solution. It has specific functional use (to ensure data consistency) and is light on resources (you do not raise brokered events that you would not watch for) but needs application to actively check for changes rather than passively wait for event to happen.

Error:Unable to locate adb within SDK in Android Studio

I struggled with this for a while. Tried to install/uninstall various packages under the SDK Manager without success. I even deleted Android Studio and reinstall it, it did not help.

I am running Android Studio 3.3 on OS X 10.14.2. At the end I tried the following:

rm -rf Library/Android/sdk

This removed the whole sdk folder. You should run this command on your home directory in terminal. (it is the default location when you open it)

I then started Android Studio and it could not find the sdk. So it prompted me to download it. I downloaded a fresh SDK and everything was working normally.

It might be an overkill but it worked.

Debugging WebSocket in Google Chrome

I have used Chrome extension called Simple WebSocket Client v0.1.3 that is published by user hakobera. It is very simple in its usage where it allows opening websockets on a given URL, send messages and close the socket connection. It is very minimalistic.

Print string and variable contents on the same line in R

The {glue} package offers string interpolation. In the example, {wd} is substituted with the contents of the variable. Complex expressions are also supported.

library(glue)

wd <- getwd()
glue("Current working dir: {wd}")
#> Current working dir: /tmp/RtmpteMv88/reprex46156826ee8c

Created on 2019-05-13 by the reprex package (v0.2.1)

Note how the printed output doesn't contain the [1] artifacts and the " quotes, for which other answers use cat().

What's wrong with nullable columns in composite primary keys?

A primary key defines a unique identifier for every row in a table: when a table has a primary key, you have a guranteed way to select any row from it.

A unique constraint does not necessarily identify every row; it just specifies that if a row has values in its columns, then they must be unique. This is not sufficient to uniquely identify every row, which is what a primary key must do.

Get JSON object from URL

$curl_handle=curl_init();
curl_setopt($curl_handle, CURLOPT_URL,'https://www.xxxSite/get_quote/ajaxGetQuoteJSON.jsp?symbol=IRCTC&series=EQ');
//Set the GET method by giving 0 value and for POST set as 1
//curl_setopt($curl_handle, CURLOPT_POST, 0);
curl_setopt($curl_handle, CURLOPT_CUSTOMREQUEST, "GET");
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
$query = curl_exec($curl_handle);
$data = json_decode($query, true);
curl_close($curl_handle);

//print complete object, just echo the variable not work so you need to use print_r to show the result
echo print_r( $data);
//at first layer
echo $data["tradedDate"];
//Inside the second layer
echo $data["data"][0]["companyName"];

Some time you might get 405, set the method type correctly.

Php, wait 5 seconds before executing an action

In Jan2018 the only solution worked for me:

<?php

if (ob_get_level() == 0) ob_start();
for ($i = 0; $i<10; $i++){

    echo "<br> Line to show.";
    echo str_pad('',4096)."\n";    

    ob_flush();
    flush();
    sleep(2);
}

echo "Done.";

ob_end_flush();

?>

How do I clear this setInterval inside a function?

Simplest way I could think of: add a class.

Simply add a class (on any element) and check inside the interval if it's there. This is more reliable, customisable and cross-language than any other way, I believe.

_x000D_
_x000D_
var i = 0;_x000D_
this.setInterval(function() {_x000D_
  if(!$('#counter').hasClass('pauseInterval')) { //only run if it hasn't got this class 'pauseInterval'_x000D_
    console.log('Counting...');_x000D_
    $('#counter').html(i++); //just for explaining and showing_x000D_
  } else {_x000D_
    console.log('Stopped counting');_x000D_
  }_x000D_
}, 500);_x000D_
_x000D_
/* In this example, I'm adding a class on mouseover and remove it again on mouseleave. You can of course do pretty much whatever you like */_x000D_
$('#counter').hover(function() { //mouse enter_x000D_
    $(this).addClass('pauseInterval');_x000D_
  },function() { //mouse leave_x000D_
    $(this).removeClass('pauseInterval');_x000D_
  }_x000D_
);_x000D_
_x000D_
/* Other example */_x000D_
$('#pauseInterval').click(function() {_x000D_
  $('#counter').toggleClass('pauseInterval');_x000D_
});
_x000D_
body {_x000D_
  background-color: #eee;_x000D_
  font-family: Calibri, Arial, sans-serif;_x000D_
}_x000D_
#counter {_x000D_
  width: 50%;_x000D_
  background: #ddd;_x000D_
  border: 2px solid #009afd;_x000D_
  border-radius: 5px;_x000D_
  padding: 5px;_x000D_
  text-align: center;_x000D_
  transition: .3s;_x000D_
  margin: 0 auto;_x000D_
}_x000D_
#counter.pauseInterval {_x000D_
  border-color: red;  _x000D_
}
_x000D_
<!-- you'll need jQuery for this. If you really want a vanilla version, ask -->_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
_x000D_
<p id="counter">&nbsp;</p>_x000D_
<button id="pauseInterval">Pause/unpause</button></p>
_x000D_
_x000D_
_x000D_

jQuery animate margin top

use 'marginTop' instead of MarginTop

$(this).find('.info').animate({ 'marginTop': '-50px', opacity: 0.5 }, 1000);

html5: display video inside canvas

var canvas = document.getElementById('canvas');
var ctx    = canvas.getContext('2d');
var video  = document.getElementById('video');

video.addEventListener('play', function () {
    var $this = this; //cache
    (function loop() {
        if (!$this.paused && !$this.ended) {
            ctx.drawImage($this, 0, 0);
            setTimeout(loop, 1000 / 30); // drawing at 30fps
        }
    })();
}, 0);

I guess the above code is self Explanatory, If not drop a comment below, I will try to explain the above few lines of code

Edit :
here's an online example, just for you :)
Demo

_x000D_
_x000D_
var canvas = document.getElementById('canvas');_x000D_
var ctx = canvas.getContext('2d');_x000D_
var video = document.getElementById('video');_x000D_
_x000D_
// set canvas size = video size when known_x000D_
video.addEventListener('loadedmetadata', function() {_x000D_
  canvas.width = video.videoWidth;_x000D_
  canvas.height = video.videoHeight;_x000D_
});_x000D_
_x000D_
video.addEventListener('play', function() {_x000D_
  var $this = this; //cache_x000D_
  (function loop() {_x000D_
    if (!$this.paused && !$this.ended) {_x000D_
      ctx.drawImage($this, 0, 0);_x000D_
      setTimeout(loop, 1000 / 30); // drawing at 30fps_x000D_
    }_x000D_
  })();_x000D_
}, 0);
_x000D_
<div id="theater">_x000D_
  <video id="video" src="http://upload.wikimedia.org/wikipedia/commons/7/79/Big_Buck_Bunny_small.ogv" controls="false"></video>_x000D_
  <canvas id="canvas"></canvas>_x000D_
  <label>_x000D_
    <br />Try to play me :)</label>_x000D_
  <br />_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to visualize an XML schema?

If you need a simple, more text-oriented documentation of your XSD, check out xs3p - a XSLT stylesheet that will transform your XSD into more readable HTML format. Quite nice, and totally free.

If that's not enough, check out some of the commercial tools out there - I personally prefer the Liquid XML Studio - not as expensive as others, and quite as capable!

How do I view executed queries within SQL Server Management Studio?

Run the following query from Management Studio on a running process:

DBCC inputbuffer( spid# )

This will return the SQL currently being run against the database for the SPID provided. Note that you need appropriate permissions to run this command.

This is better than running a trace since it targets a specific SPID. You can see if it's long running based on its CPUTime and DiskIO.

Example to get details of SPID 64:

DBCC inputbuffer(64)

CSS Font "Helvetica Neue"

Helvetica Neue is a paid font, so you shouldn't @font-face it, as you'd be freely distributing a copyrighted font. It's included in Mac systems but not in windows/linux ones, so yes, plenty of your users wont have it installed. Anyway, you can use 'Arial Narrow' as a windows substitute, which is it's windows equivalent.

Trim spaces from end of a NSString

Swift version

Only trims spaces at the end of the String:

private func removingSpacesAtTheEndOfAString(var str: String) -> String {
    var i: Int = countElements(str) - 1, j: Int = i

    while(i >= 0 && str[advance(str.startIndex, i)] == " ") {
        --i
    }

    return str.substringWithRange(Range<String.Index>(start: str.startIndex, end: advance(str.endIndex, -(j - i))))
}

Trims spaces on both sides of the String:

var str: String = " Yolo "
var trimmedStr: String = str.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())

How to see local history changes in Visual Studio Code?

I built an extension called Checkpoints, an alternative to Local History. Checkpoints has support for viewing history for all files (that has checkpoints) in the tree view, not just the currently active file. There are some other minor differences aswell, but overall they are pretty similar.

Dropdown using javascript onchange

easy

<script>
jQuery.noConflict()(document).ready(function() {
    $('#hide').css('display','none');
    $('#plano').change(function(){

        if(document.getElementById('plano').value == 1){
            $('#hide').show('slow');    

        }else 
            if(document.getElementById('plano').value == 0){

             $('#hide').hide('slow'); 
        }else
            if(document.getElementById('plano').value == 0){
             $('#hide').css('display','none');  

            }

    });
    $('#plano').change();
});
</script>

this example shows and hides the div if selected in combobox some specific value

How to open html file?

You can read HTML page using 'urllib'.

 #python 2.x

  import urllib

  page = urllib.urlopen("your path ").read()
  print page

Resize a picture to fit a JLabel

You can try it:

ImageIcon imageIcon = new ImageIcon(new ImageIcon("icon.png").getImage().getScaledInstance(20, 20, Image.SCALE_DEFAULT));
label.setIcon(imageIcon);

Or in one line:

label.setIcon(new ImageIcon(new ImageIcon("icon.png").getImage().getScaledInstance(20, 20, Image.SCALE_DEFAULT)));

The execution time is much more faster than File and ImageIO.

I recommend you to compare the two solutions in a loop.

How do I use regular expressions in bash scripts?

It was changed between 3.1 and 3.2:

This is a terse description of the new features added to bash-3.2 since the release of bash-3.1.

Quoting the string argument to the [[ command's =~ operator now forces string matching, as with the other pattern-matching operators.

So use it without the quotes thus:

i="test"
if [[ $i =~ 200[78] ]] ; then
    echo "OK"
else
    echo "not OK"
fi

send mail from linux terminal in one line

For Ubuntu users: First You need to install mailutils

sudo apt-get install mailutils

Setup an email server, if you are using gmail or smtp. follow this link. then use this command to send email.

echo "this is a test mail" | mail -s "Subject of mail" [email protected]

In case you are using gmail and still you are getting some authentication error then you need to change setting of gmail:

Turn on Access for less secure apps from here

Alter and Assign Object Without Side Effects

Try this instead:

var myArray = [];

myArray.push({ id: 0, value: 1 });
myArray.push({ id: 2, value: 3 });

or will this not work for your situation?

Chrome disable SSL checking for sites?

In my case I was developing an ASP.Net MVC5 web app and the certificate errors on my local dev machine (IISExpress certificate) started becoming a practical concern once I started working with service workers. Chrome simply wouldn't register my service worker because of the certificate error.

I did, however, notice that during my automated Selenium browser tests, Chrome seem to just "ignore" all these kinds of problems (e.g. the warning page about an insecure site), so I asked myself the question: How is Selenium starting Chrome for running its tests, and might it also solve the service worker problem?

Using Process Explorer on Windows, I was able to find out the command-line arguments with which Selenium is starting Chrome:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-background-networking --disable-client-side-phishing-detection --disable-default-apps --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --disable-web-resources --enable-automation --enable-logging --force-fieldtrials=SiteIsolationExtensions/Control --ignore-certificate-errors --log-level=0 --metrics-recording-only --no-first-run --password-store=basic --remote-debugging-port=12207 --safebrowsing-disable-auto-update --test-type=webdriver --use-mock-keychain --user-data-dir="C:\Users\Sam\AppData\Local\Temp\some-non-existent-directory" data:,

There are a bunch of parameters here that I didn't end up doing necessity-testing for, but if I run Chrome this way, my service worker registers and works as expected.

The only one that does seem to make a difference is the --user-data-dir parameter, which to make things work can be set to a non-existent directory (things won't work if you don't provide the parameter).

Hope that helps someone else with a similar problem. I'm using Chrome 60.0.3112.90.

Constructor overloading in Java - best practice

It really depends on the kind of classes as not all classes are created equal.

As general guideline I would suggest 2 options:

  • For value & immutable classes (Exception, Integer, DTOs and such) use single primary constructor as suggested in above answer
  • For everything else (session beans, services, mutable objects, JPA & JAXB entities and so on) use default constructor only with sensible defaults on all the properties so it can be used without additional configuration

Log4j: How to configure simplest possible file logging?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">

   <appender name="fileAppender" class="org.apache.log4j.RollingFileAppender">
      <param name="Threshold" value="INFO" />
      <param name="File" value="sample.log"/>
      <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d %-5p  [%c{1}] %m %n" />
      </layout>
   </appender>

  <root> 
    <priority value ="debug" /> 
    <appender-ref ref="fileAppender" /> 
  </root> 

</log4j:configuration>

Log4j can be a bit confusing. So lets try to understand what is going on in this file: In log4j you have two basic constructs appenders and loggers.

Appenders define how and where things are appended. Will it be logged to a file, to the console, to a database, etc.? In this case you are specifying that log statements directed to fileAppender will be put in the file sample.log using the pattern specified in the layout tags. You could just as easily create a appender for the console or the database. Where the console appender would specify things like the layout on the screen and the database appender would have connection details and table names.

Loggers respond to logging events as they bubble up. If an event catches the interest of a specific logger it will invoke its attached appenders. In the example below you have only one logger the root logger - which responds to all logging events by default. In addition to the root logger you can specify more specific loggers that respond to events from specific packages. These loggers can have their own appenders specified using the appender-ref tags or will otherwise inherit the appenders from the root logger. Using more specific loggers allows you to fine tune the logging level on specific packages or to direct certain packages to other appenders.

So what this file is saying is:

  1. Create a fileAppender that logs to file sample.log
  2. Attach that appender to the root logger.
  3. The root logger will respond to any events at least as detailed as 'debug' level
  4. The appender is configured to only log events that are at least as detailed as 'info'

The net out is that if you have a logger.debug("blah blah") in your code it will get ignored. A logger.info("Blah blah"); will output to sample.log.

The snippet below could be added to the file above with the log4j tags. This logger would inherit the appenders from <root> but would limit the all logging events from the package org.springframework to those logged at level info or above.

  <!-- Example Package level Logger -->
    <logger name="org.springframework">
        <level value="info"/>
    </logger>   

How to change the cursor into a hand when a user hovers over a list item?

In light of the passage of time, as people have mentioned, you can now safely just use:

li { cursor: pointer; }

Sort an ArrayList based on an object field

You can use the Bean Comparator to sort on any property in your custom class.

IF - ELSE IF - ELSE Structure in Excel

=IF(CR<=10, "RED", if(CR<50, "YELLOW", if(CR<101, "GREEN")))

CR = ColRow (Cell) This is an example. In this example when value in Cell is less then or equal to 10 then RED word will appear on that cell. In the same manner other if conditions are true if first if is false.

How to parse float with two decimal places in javascript?

Try this (see comments in code):

function fixInteger(el) {
    // this is element's value selector, you should use your own
    value = $(el).val();
    if (value == '') {
        value = 0;
    }
    newValue = parseInt(value);
    // if new value is Nan (when input is a string with no integers in it)
    if (isNaN(newValue)) {
        value = 0;
        newValue = parseInt(value);
    }
    // apply new value to element
    $(el).val(newValue);
}

function fixPrice(el) {
    // this is element's value selector, you should use your own
    value = $(el).val();
    if (value == '') {
        value = 0;
    }
    newValue = parseFloat(value.replace(',', '.')).toFixed(2);
    // if new value is Nan (when input is a string with no integers in it)
    if (isNaN(newValue)) {
        value = 0;
        newValue = parseFloat(value).toFixed(2);
    }
    // apply new value to element
    $(el).val(newValue);
}

Convert Newtonsoft.Json.Linq.JArray to a list of specific object type

I can think of different method to achieve the same

IList<SelectableEnumItem> result= array;

or (i had some situation that this one didn't work well)

var result = (List<SelectableEnumItem>) array;

or use linq extension

var result = array.CastTo<List<SelectableEnumItem>>();

or

var result= array.Select(x=> x).ToArray<SelectableEnumItem>();

or more explictly

var result= array.Select(x=> new SelectableEnumItem{FirstName= x.Name, Selected = bool.Parse(x.selected) });

please pay attention in above solution I used dynamic Object

I can think of some more solutions that are combinations of above solutions. but I think it covers almost all available methods out there.

Myself I use the first one

C# how to convert File.ReadLines into string array?

Change string[] lines = File.ReadLines("c:\\file.txt"); to IEnumerable<string> lines = File.ReadLines("c:\\file.txt"); The rest of your code should work fine.

Encoding Javascript Object to Json string

Unless the variable k is defined, that's probably what's causing your trouble. Something like this will do what you want:

var new_tweets = { };

new_tweets.k = { };

new_tweets.k.tweet_id = 98745521;
new_tweets.k.user_id = 54875;

new_tweets.k.data = { };

new_tweets.k.data.in_reply_to_screen_name = 'other_user';
new_tweets.k.data.text = 'tweet text';

// Will create the JSON string you're looking for.
var json = JSON.stringify(new_tweets);

You can also do it all at once:

var new_tweets = {
  k: {
    tweet_id: 98745521,
    user_id: 54875,
    data: {
      in_reply_to_screen_name: 'other_user',
      text: 'tweet_text'
    }
  }
}

How can I use a batch file to write to a text file?

echo "blahblah"> txt.txt will erase the txt and put blahblah in it's place

echo "blahblah">> txt.txt will write blahblah on a new line in the txt

I think that both will create a new txt if none exists (I know that the first one does)

Where "txt.txt" is written above, a file path can be inserted if wanted. e.g. C:\Users\<username>\desktop, which will put it on their desktop.

Spring Boot - inject map from application.yml

I run into the same problem today, but unfortunately Andy's solution didn't work for me. In Spring Boot 1.2.1.RELEASE it's even easier, but you have to be aware of a few things.

Here is the interesting part from my application.yml:

oauth:
  providers:
    google:
     api: org.scribe.builder.api.Google2Api
     key: api_key
     secret: api_secret
     callback: http://callback.your.host/oauth/google

providers map contains only one map entry, my goal is to provide dynamic configuration for other OAuth providers. I want to inject this map into a service that will initialize services based on the configuration provided in this yaml file. My initial implementation was:

@Service
@ConfigurationProperties(prefix = 'oauth')
class OAuth2ProvidersService implements InitializingBean {

    private Map<String, Map<String, String>> providers = [:]

    @Override
    void afterPropertiesSet() throws Exception {
       initialize()
    }

    private void initialize() {
       //....
    }
}

After starting the application, providers map in OAuth2ProvidersService was not initialized. I tried the solution suggested by Andy, but it didn't work as well. I use Groovy in that application, so I decided to remove private and let Groovy generates getter and setter. So my code looked like this:

@Service
@ConfigurationProperties(prefix = 'oauth')
class OAuth2ProvidersService implements InitializingBean {

    Map<String, Map<String, String>> providers = [:]

    @Override
    void afterPropertiesSet() throws Exception {
       initialize()
    }

    private void initialize() {
       //....
    }
}

After that small change everything worked.

Although there is one thing that might be worth mentioning. After I make it working I decided to make this field private and provide setter with straight argument type in the setter method. Unfortunately it wont work that. It causes org.springframework.beans.NotWritablePropertyException with message:

Invalid property 'providers[google]' of bean class [com.zinvoice.user.service.OAuth2ProvidersService]: Cannot access indexed value in property referenced in indexed property path 'providers[google]'; nested exception is org.springframework.beans.NotReadablePropertyException: Invalid property 'providers[google]' of bean class [com.zinvoice.user.service.OAuth2ProvidersService]: Bean property 'providers[google]' is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?

Keep it in mind if you're using Groovy in your Spring Boot application.

How can I get a side-by-side diff when I do "git diff"?

You can also try git diff --word-diff. It's not exactly side-by-side, but somehow better, so you might prefer it to your actual side-by-side need.

Android Studio Emulator and "Process finished with exit code 0"

I had this issue in Android Studio 3.1 :

I only have on board graphics. Went to Tools -> AVD Manager -> (Edit this AVD) under Actions -> Emulated Performance (Graphics): select "Software GLES 2.0".

How to create a file in Ruby

OK, now I feel stupid. The first two definitely do not work but the second two do. Not sure how I convinced my self that I had tried them. Sorry for wasting everyone's time.

In case this helps anyone else, this can occur when you are trying to make a new file in a directory that does not exist.

How to import a new font into a project - Angular 5

You need to put the font files in assets folder (may be a fonts sub-folder within assets) and refer to it in the styles:

@font-face {
  font-family: lato;
  src: url(assets/font/Lato.otf) format("opentype");
}

Once done, you can apply this font any where like:

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'lato', 'arial', sans-serif;
}

You can put the @font-face definition in your global styles.css or styles.scss and you would be able to refer to the font anywhere - even in your component specific CSS/SCSS. styles.css or styles.scss is already defined in angular-cli.json. Or, if you want you can create a separate CSS/SCSS file and declare it in angular-cli.json along with the styles.css or styles.scss like:

"styles": [
  "styles.css",
  "fonts.css"
],

How to delete row in gridview using rowdeleting event?

Your delete code looks like this

Gridview1.DeleteRow(e.RowIndex);
Gridview1.DataBind();

When you call Gridview1.DataBind() you will populate your gridview with the current datasource. So, it will delete all the existent rows, and it will add all the rows from CustomersSqlDataSource.

What you need to do is delete the row from the table that CustomersSqlDataSource querying.

You can do this very easy by setting a delete command to CustomersSqlDataSource, add a delete parameter, and then execute the delete command.

CustomersSqlDataSource.DeleteCommand = "DELETE FROM Customer Where CustomerID=@CustomerID"; // Customer is the name of the table where you take your data from. Maybe you named it different 
CustomersSqlDataSource.DeleteParameters.Add("CustomerID", Gridview1.DataKeys[e.RowIndex].Values["CustomerID"].ToString());
CustomersSqlDataSource.Delete();
Gridview1.DataBind();

But take into account that this will delete the data from the database.

set up device for development (???????????? no permissions)

Enter the following commands:

adb kill-server
sudo ./adb start-server
adb devices

This happens when you are not running adb server as root.

ResourceDictionary in a separate assembly

I'm working with .NET 4.5 and couldn't get this working... I was using WPF Custom Control Library. This worked for me in the end...

<ResourceDictionary Source="/MyAssembly;component/mytheme.xaml" />

source: http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/11a42336-8d87-4656-91a3-275413d3cc19

Initializing ArrayList with some predefined values

I would suggest to use Arrays.asList() for single line initialization. For different ways of declaring and initializing a List you can also refer Initialization of ArrayList in Java

How to resolve Unable to load authentication plugin 'caching_sha2_password' issue

Starting with MySQL 8.0.4, they have changed the default authentication plugin for MySQL server from mysql_native_password to caching_sha2_password.

You can run the below command to resolve the issue.

sample username / password => student / pass123

ALTER USER 'student'@'localhost' IDENTIFIED WITH mysql_native_password BY 'pass123';

Refer the official page for details: MySQL Reference Manual

Uncaught SyntaxError: Invalid or unexpected token

I also had an issue with multiline strings in this scenario. @Iman's backtick(`) solution worked great in the modern browsers but caused an invalid character error in Internet Explorer. I had to use the following:

'@item.MultiLineString.Replace(Environment.NewLine, "<br />")'

Then I had to put the carriage returns back again in the js function. Had to use RegEx to handle multiple carriage returns.

// This will work for the following:
// "hello\nworld"
// "hello<br>world"
// "hello<br />world"
$("#MyTextArea").val(multiLineString.replace(/\n|<br\s*\/?>/gi, "\r"));

How to convert image file data in a byte array to a Bitmap?

The answer of Uttam didnt work for me. I just got null when I do:

Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapdata, 0, bitmapdata.length);

In my case, bitmapdata only has the buffer of the pixels, so it is imposible for the function decodeByteArray to guess which the width, the height and the color bits use. So I tried this and it worked:

//Create bitmap with width, height, and 4 bytes color (RGBA)    
Bitmap bmp = Bitmap.createBitmap(imageWidth, imageHeight, Bitmap.Config.ARGB_8888);
ByteBuffer buffer = ByteBuffer.wrap(bitmapdata);
bmp.copyPixelsFromBuffer(buffer);

Check https://developer.android.com/reference/android/graphics/Bitmap.Config.html for different color options

Hibernate Group by Criteria Object

Please refer to this for the example .The main point is to use the groupProperty() , and the related aggregate functions provided by the Projections class.

For example :

SELECT column_name, max(column_name) , min (column_name) , count(column_name)
FROM table_name
WHERE column_name > xxxxx
GROUP BY column_name

Its equivalent criteria object is :

List result = session.createCriteria(SomeTable.class)       
                    .add(Restrictions.ge("someColumn", xxxxx))      
                    .setProjection(Projections.projectionList()
                            .add(Projections.groupProperty("someColumn"))
                            .add(Projections.max("someColumn"))
                            .add(Projections.min("someColumn"))
                            .add(Projections.count("someColumn"))           
                    ).list();

SQL Query to find the last day of the month

declare @date datetime;
set @date = getdate(); -- or some date
select dateadd(month,1+datediff(month,0,@date),-1);

Escape double quote in grep

The problem is that you aren't correctly escaping the input string, try:

echo "\"member\":\"time\"" | grep -e "member\""

Alternatively, you can use unescaped double quotes within single quotes:

echo '"member":"time"' | grep -e 'member"'

It's a matter of preference which you find clearer, although the second approach prevents you from nesting your command within another set of single quotes (e.g. ssh 'cmd').

linux: kill background task

This should kill all background processes:

jobs -p | xargs kill -9

Javascript : array.length returns undefined

Objects don't have a .length property.

A simple solution if you know you don't have to worry about hasOwnProperty checks, would be to do this:

Object.keys(data).length;

If you have to support IE 8 or lower, you'll have to use a loop, instead:

var length= 0;
for(var key in data) {
    if(data.hasOwnProperty(key)){
        length++;
    }
}

How can I pair socks from a pile efficiently?

Socks, whether real ones or some analogous data structure, would be supplied in pairs.

The simplest answer is prior to allowing the pair to be separated, a single data structure for the pair should have been initialized that contained a pointer to the left and right sock, thus enabling socks to be referred to directly or via their pair. A sock may also be extended to contain a pointer to its partner.

This solves any computational pairing problem by removing it with a layer of abstraction.

Applying the same idea to the practical problem of pairing socks, the apparent answer is: don't allow your socks to ever be unpaired. Socks are provided as a pair, put in the drawer as a pair (perhaps by balling them together), worn as a pair. But the point where unpairing is possible is in the washer, so all that's required is a physical mechanism that allows the socks to stay together and be washed efficiently.

There are two physical possibilities:

For a 'pair' object that keeps a pointer to each sock we could have a cloth bag that we use to keep the socks together. This seems like massive overhead.

But for each sock to keep a reference to the other, there is a neat solution: a popper (or a 'snap button' if you're American), such as these:

http://www.aliexpress.com/compare/compare-invisible-snap-buttons.html

Then all you do is snap your socks together right after you take them off and put them in your washing basket, and again you've removed the problem of needing to pair your socks with a physical abstraction of the 'pair' concept.

How to call Stored Procedure in Entity Framework 6 (Code-First)?

I solved it with ExecuteSqlCommand

Put your own method like mine in DbContext as your own instances:

public void addmessage(<yourEntity> _msg)
{
    var date = new SqlParameter("@date", _msg.MDate);
    var subject = new SqlParameter("@subject", _msg.MSubject);
    var body = new SqlParameter("@body", _msg.MBody);
    var fid = new SqlParameter("@fid", _msg.FID);
    this.Database.ExecuteSqlCommand("exec messageinsert @Date , @Subject , @Body , @Fid", date,subject,body,fid);
}

so you can have a method in your code-behind like this :

[WebMethod] //this method is static and i use web method because i call this method from client side
public static void AddMessage(string Date, string Subject, string Body, string Follower, string Department)
{
    try
    {
        using (DBContext reposit = new DBContext())
        {
            msge <yourEntity> Newmsg = new msge();
            Newmsg.MDate = Date;
            Newmsg.MSubject = Subject.Trim();
            Newmsg.MBody = Body.Trim();
            Newmsg.FID= 5;
            reposit.addmessage(Newmsg);
        }
    }
    catch (Exception)
    {
        throw;
    }
}

this is my SP :

Create PROCEDURE dbo.MessageInsert

    @Date nchar["size"],
    @Subject nchar["size"],
    @Body nchar["size"],
    @Fid int
AS
    insert into Msg (MDate,MSubject,MBody,FID) values (@Date,@Subject,@Body,@Fid)
    RETURN

hope helped you

How do you create a read-only user in PostgreSQL?

The not straightforward way of doing it would be granting select on each table of the database:

postgres=# grant select on db_name.table_name to read_only_user;

You could automate that by generating your grant statements from the database metadata.

Changing background color of selected cell?

For iOS7+ and if you are using Interface Builder then subclass your cell and implement:

Objective-C

- (void)awakeFromNib {
    [super awakeFromNib];
    // Default Select background
    UIView *v = [[UIView alloc] init];
    v.backgroundColor = [UIColor redColor];
    self.selectedBackgroundView = v;
}

Swift 2.2

override func awakeFromNib() {
    super.awakeFromNib()
    // Default Select background
    self.selectedBackgroundView = { view in
        view.backgroundColor = .redColor()
        return view
    }(UIView())
}

What is the purpose of Looper and how to use it?

What is Looper?

FROM DOCS

Looper

Looper Class used to run a message loop for a thread. Threads by default do not have a message loop associated with them; to create one, call prepare() in the thread that is to run the loop, and then loop() to have it process messages until the loop is stopped.

  • A Looper is a message handling loop:
  • An important character of Looper is that it's associated with the thread within which the Looper is created
  • The Looper class maintains a MessageQueue, which contains a list messages. An important character of Looper is that it's associated with the thread within which the Looper is created.
  • The Looper is named so because it implements the loop – takes the next task, executes it, then takes the next one and so on. The Handler is called a handler because someone could not invent a better name
  • Android Looper is a Java class within the Android user interface that together with the Handler class to process UI events such as button clicks, screen redraws and orientation switches.

How it works?

enter image description here

Creating Looper

A thread gets a Looper and MessageQueue by calling Looper.prepare() after its running. Looper.prepare() identifies the calling thread, creates a Looper and MessageQueue object and associate the thread

SAMPLE CODE

class MyLooperThread extends Thread {

      public Handler mHandler; 

      public void run() { 

          // preparing a looper on current thread  
          Looper.prepare();

          mHandler = new Handler() { 
              public void handleMessage(Message msg) { 
                 // process incoming messages here
                 // this will run in non-ui/background thread
              } 
          }; 

          Looper.loop();
      } 
  }

For more information check below post

Count lines in large files

On a multi-core server, use GNU parallel to count file lines in parallel. After each files line count is printed, bc sums all line counts.

find . -name '*.txt' | parallel 'wc -l {}' 2>/dev/null | paste -sd+ - | bc

To save space, you can even keep all files compressed. The following line uncompresses each file and counts its lines in parallel, then sums all counts.

find . -name '*.xz' | parallel 'xzcat {} | wc -l' 2>/dev/null | paste -sd+ - | bc

Using lambda expressions for event handlers

EventHandler handler = (s, e) => MessageBox.Show("Woho");

button.Click += handler;
button.Click -= handler;

How can I position my div at the bottom of its container?

Using the translateY and top property

Just set element child to position: relative and than move it top: 100% (that's the 100% height of the parent) and stick to bottom of parent by transform: translateY(-100%) (that's -100% of the height of the child).

BenefitS

  • you do not take the element from the page flow
  • it is dynamic

But still just workaround :(

.copyright{
   position: relative;
   top: 100%;
   transform: translateY(-100%);
}

Don't forget prefixes for the older browser.

jQuery $.ajax(), pass success data into separate function

You can use this keyword to access custom data, passed to $.ajax() function:

    $.ajax({
        // ... // --> put ajax configuration parameters here
        yourCustomData: {param1: 'any value', time: '1h24'},  // put your custom key/value pair here
        success: successHandler
    });

    function successHandler(data, textStatus, jqXHR) {
        alert(this.yourCustomData.param1);  // shows "any value"
        console.log(this.yourCustomData.time);
    }

Getting values from query string in an url using AngularJS $location

My fix is more simple, create a factory, and implement as one variable. For example

_x000D_
_x000D_
angular.module('myApp', [])_x000D_
_x000D_
// This a searchCustom factory. Copy the factory and implement in the controller_x000D_
.factory("searchCustom", function($http,$log){    _x000D_
    return {_x000D_
        valuesParams : function(params){_x000D_
            paramsResult = [];_x000D_
            params = params.replace('(', '').replace(')','').split("&");_x000D_
            _x000D_
            for(x in params){_x000D_
                paramsKeyTmp = params[x].split("=");_x000D_
                _x000D_
                // Si el parametro esta disponible anexamos al vector paramResult_x000D_
                if (paramsKeyTmp[1] !== '' && paramsKeyTmp[1] !== ' ' && _x000D_
                    paramsKeyTmp[1] !== null){          _x000D_
                    _x000D_
                    paramsResult.push(params[x]);_x000D_
                }_x000D_
            }_x000D_
            _x000D_
            return paramsResult;_x000D_
        }_x000D_
    }_x000D_
})_x000D_
_x000D_
.controller("SearchController", function($scope, $http,$routeParams,$log,searchCustom){_x000D_
    $ctrl = this;_x000D_
    _x000D_
    var valueParams = searchCustom.valuesParams($routeParams.value);_x000D_
    valueParams = valueParams.join('&');_x000D_
_x000D_
    $http({_x000D_
        method : "GET",_x000D_
        url: webservice+"q?"+valueParams_x000D_
    }).then( function successCallback(response){_x000D_
        data = response.data;_x000D_
        $scope.cantEncontrados = data.length; _x000D_
        $scope.dataSearch = data;_x000D_
        _x000D_
    } , function errorCallback(response){_x000D_
        console.log(response.statusText);_x000D_
    })_x000D_
      _x000D_
})
_x000D_
<html>_x000D_
<head>_x000D_
</head>_x000D_
<body ng-app="myApp">_x000D_
<div ng-controller="SearchController">_x000D_
<form action="#" >_x000D_
                          _x000D_
                            _x000D_
                            <input ng-model="param1" _x000D_
                                   placeholder="param1" />_x000D_
                            _x000D_
                            <input  ng-model="param2" _x000D_
                                    placeholder="param2"/>_x000D_
                        _x000D_
<!-- Implement in the html code _x000D_
(param1={{param1}}&param2={{param2}}) -> this is a one variable, the factory searchCustom split and restructure in the array params_x000D_
-->          _x000D_
                        <a href="#seach/(param1={{param1}}&param2={{param2}})">_x000D_
                            <buttom ng-click="searchData()" >Busqueda</buttom>_x000D_
                        </a>_x000D_
                    </form> _x000D_
</div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

Convert factor to integer

Quoting directly from the help page for factor:

To transform a factor f to its original numeric values, as.numeric(levels(f))[f] is recommended and slightly more efficient than as.numeric(as.character(f)).

Why do we use arrays instead of other data structures?

Time to go back in time for a lesson. While we don't think about these things much in our fancy managed languages today, they are built on the same foundation, so let's look at how memory is managed in C.

Before I dive in, a quick explanation of what the term "pointer" means. A pointer is simply a variable that "points" to a location in memory. It doesn't contain the actual value at this area of memory, it contains the memory address to it. Think of a block of memory as a mailbox. The pointer would be the address to that mailbox.

In C, an array is simply a pointer with an offset, the offset specifies how far in memory to look. This provides O(1) access time.

  MyArray   [5]
     ^       ^
  Pointer  Offset

All other data structures either build upon this, or do not use adjacent memory for storage, resulting in poor random access look up time (Though there are other benefits to not using sequential memory).

For example, let's say we have an array with 6 numbers (6,4,2,3,1,5) in it, in memory it would look like this:

=====================================
|  6  |  4  |  2  |  3  |  1  |  5  |
=====================================

In an array, we know that each element is next to each other in memory. A C array (Called MyArray here) is simply a pointer to the first element:

=====================================
|  6  |  4  |  2  |  3  |  1  |  5  |
=====================================
   ^
MyArray

If we wanted to look up MyArray[4], internally it would be accessed like this:

   0     1     2     3     4 
=====================================
|  6  |  4  |  2  |  3  |  1  |  5  |
=====================================
                           ^
MyArray + 4 ---------------/
(Pointer + Offset)

Because we can directly access any element in the array by adding the offset to the pointer, we can look up any element in the same amount of time, regardless of the size of the array. This means that getting MyArray[1000] would take the same amount of time as getting MyArray[5].

An alternative data structure is a linked list. This is a linear list of pointers, each pointing to the next node

========    ========    ========    ========    ========
| Data |    | Data |    | Data |    | Data |    | Data |
|      | -> |      | -> |      | -> |      | -> |      | 
|  P1  |    |  P2  |    |  P3  |    |  P4  |    |  P5  |        
========    ========    ========    ========    ========

P(X) stands for Pointer to next node.

Note that I made each "node" into its own block. This is because they are not guaranteed to be (and most likely won't be) adjacent in memory.

If I want to access P3, I can't directly access it, because I don't know where it is in memory. All I know is where the root (P1) is, so instead I have to start at P1, and follow each pointer to the desired node.

This is a O(N) look up time (The look up cost increases as each element is added). It is much more expensive to get to P1000 compared to getting to P4.

Higher level data structures, such as hashtables, stacks and queues, all may use an array (or multiple arrays) internally, while Linked Lists and Binary Trees usually use nodes and pointers.

You might wonder why anyone would use a data structure that requires linear traversal to look up a value instead of just using an array, but they have their uses.

Take our array again. This time, I want to find the array element that holds the value '5'.

=====================================
|  6  |  4  |  2  |  3  |  1  |  5  |
=====================================
   ^     ^     ^     ^     ^   FOUND!

In this situation, I don't know what offset to add to the pointer to find it, so I have to start at 0, and work my way up until I find it. This means I have to perform 6 checks.

Because of this, searching for a value in an array is considered O(N). The cost of searching increases as the array gets larger.

Remember up above where I said that sometimes using a non sequential data structure can have advantages? Searching for data is one of these advantages and one of the best examples is the Binary Tree.

A Binary Tree is a data structure similar to a linked list, however instead of linking to a single node, each node can link to two children nodes.

         ==========
         |  Root  |         
         ==========
        /          \ 
  =========       =========
  | Child |       | Child |
  =========       =========
                  /       \
            =========    =========
            | Child |    | Child |
            =========    =========

 Assume that each connector is really a Pointer

When data is inserted into a binary tree, it uses several rules to decide where to place the new node. The basic concept is that if the new value is greater than the parents, it inserts it to the left, if it is lower, it inserts it to the right.

This means that the values in a binary tree could look like this:

         ==========
         |   100  |         
         ==========
        /          \ 
  =========       =========
  |  200  |       |   50  |
  =========       =========
                  /       \
            =========    =========
            |   75  |    |   25  |
            =========    =========

When searching a binary tree for the value of 75, we only need to visit 3 nodes ( O(log N) ) because of this structure:

  • Is 75 less than 100? Look at Right Node
  • Is 75 greater than 50? Look at Left Node
  • There is the 75!

Even though there are 5 nodes in our tree, we did not need to look at the remaining two, because we knew that they (and their children) could not possibly contain the value we were looking for. This gives us a search time that at worst case means we have to visit every node, but in the best case we only have to visit a small portion of the nodes.

That is where arrays get beat, they provide a linear O(N) search time, despite O(1) access time.

This is an incredibly high level overview on data structures in memory, skipping over a lot of details, but hopefully it illustrates an array's strength and weakness compared to other data structures.

How do I resolve `The following packages have unmet dependencies`

If sudo apt-get install -f <package-name> doesn't work, try aptitude:

sudo apt-get install aptitude
sudo aptitude install <package-name>

Aptitude will try to resolve the problem.

As an example, in my case, I still receive some error when try to install libcurl4-openssl-dev:

sudo apt-get install -f libcurl4-openssl-dev

So i try aptitude, it turns out I have to downgrade some packages.

The following actions will resolve these dependencies:

    Keep the following packages at their current version:
    1)     libyaml-dev [Not Installed]                        

Accept this solution? [Y/n/q/? (n)

The following actions will resolve these dependencies:

    Downgrade the following packages:                                
    1)     libyaml-0-2 [0.1.4-3ubuntu3.1 (now) -> 0.1.4-3ubuntu3 (trusty)]

Accept this solution? [Y/n/q/?] (Y)

How can I drop a table if there is a foreign key constraint in SQL Server?

    --Find and drop the constraints

    DECLARE @dynamicSQL VARCHAR(MAX)
    DECLARE MY_CURSOR CURSOR 

    LOCAL STATIC READ_ONLY FORWARD_ONLY 
    FOR
        SELECT dynamicSQL = 'ALTER TABLE [' +  OBJECT_SCHEMA_NAME(parent_object_id) + '].[' + OBJECT_NAME(parent_object_id) + '] DROP CONSTRAINT [' + name + ']'
        FROM sys.foreign_keys
        WHERE object_name(referenced_object_id)  in ('table1', 'table2', 'table3')
    OPEN MY_CURSOR
    FETCH NEXT FROM MY_CURSOR INTO @dynamicSQL
    WHILE @@FETCH_STATUS = 0
    BEGIN

        PRINT @dynamicSQL
        EXEC (@dynamicSQL)

        FETCH NEXT FROM MY_CURSOR INTO @dynamicSQL
    END
    CLOSE MY_CURSOR
    DEALLOCATE MY_CURSOR


    -- Drop tables
    DROP 'table1'
    DROP 'table2'
    DROP 'table3'

Curl command without using cache

I know this is an older question, but I wanted to post an answer for users with the same question:

curl -H 'Cache-Control: no-cache' http://www.example.com

This curl command servers in its header request to return non-cached data from the web server.

Drop shadow on a div container?

You can try using the PNG drop shadows. IE6 doesn't support it, however it will degrade nicely.

http://www.positioniseverything.net/articles/dropshadows.html

You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application

For me this simple command solved the problem:

sudo apt-get install postgresql postgresql-contrib libpq-dev python-dev

Then I can do:

 pip install psycopg2

Multipart File Upload Using Spring Rest Template + Spring Web MVC

Here are my working example

@RequestMapping(value = "/api/v1/files/upload", method =RequestMethod.POST)
public ResponseEntity<?> upload(@RequestParam("files") MultipartFile[] files) {
    LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
    List<String> tempFileNames = new ArrayList<>();
    String tempFileName;
    FileOutputStream fo;

    try {
        for (MultipartFile file : files) {
            tempFileName = "/tmp/" + file.getOriginalFilename();
            tempFileNames.add(tempFileName);
            fo = new FileOutputStream(tempFileName);
            fo.write(file.getBytes());
            fo.close();
            map.add("files", new FileSystemResource(tempFileName));
        }

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);

        HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new HttpEntity<>(map, headers);
        String response = restTemplate.postForObject(uploadFilesUrl, requestEntity, String.class);

    } catch (IOException e) {
        e.printStackTrace();
    }

    for (String fileName : tempFileNames) {
        File f = new File(fileName);
        f.delete();
    }
    return new ResponseEntity<Object>(HttpStatus.OK);
}

What is the role of the bias in neural networks?

This thread really helped me developing my own project. Here are some further illustrations showing the result of a simple 2-layer feed forward neural network with and without bias units on a two-variable regression problem. Weights are initialized randomly and standard ReLU activation is used. As the answers before me concluded, without the bias the ReLU-network is not able to deviate from zero at (0,0).

enter image description here enter image description here enter image description here

Can I write native iPhone apps using Python?

Yes, nowadays you can develop apps for iOS in Python.

There are two frameworks that you may want to checkout: Kivy and PyMob.

Please consider the answers to this question too, as they are more up-to-date than this one.

Printing out a number in assembly language?

PRINT_SUM PROC NEAR
 CMP AL, 0
 JNE PRINT_AX
 PUSH AX
 MOV AL, '0'
 MOV AH, 0EH
 INT 10H
 POP AX
 RET 
    PRINT_AX:    
 PUSHA
 MOV AH, 0
 CMP AX, 0
 JE PN_DONE
 MOV DL, 10
 DIV DL    
 CALL PRINT_AX
 MOV AL, AH
 ADD AL, 30H
 MOV AH, 0EH
 INT 10H    
    PN_DONE:
 POPA  
 RET  
PRINT_SUM ENDP

Elegant way to read file into byte[] array in Java

Use a ByteArrayOutputStream. Here is the process:

  • Get an InputStream to read data
  • Create a ByteArrayOutputStream.
  • Copy all the InputStream into the OutputStream
  • Get your byte[] from the ByteArrayOutputStream using the toByteArray() method

React JS get current date

Your problem is that you are naming your component class Date. When you call new Date() within your class, it won't create an instance of the Date you expect it to create (which is likely this Date)- it will try to create an instance of your component class. Then the constructor will try to create another instance, and another instance, and another instance... Until you run out of stack space and get the error you're seeing.

If you want to use Date within your class, try naming your class something different such as Calendar or DateComponent.

The reason for this is how JavaScript deals with name scope: Whenever you create a new named entity, if there is already an entity with that name in scope, that name will stop referring to the previous entity and start referring to your new entity. So if you use the name Date within a class named Date, the name Date will refer to that class and not to any object named Date which existed before the class definition started.

Can I write a CSS selector selecting elements NOT having a certain class or attribute?

Example

  [class*='section-']:not(.section-name) {
    @include opacity(0.6);
    // Write your css code here
  }

// Opacity 0.6 all "section-" but not "section-name"

What does the exclamation mark do before the function?

Exclamation mark makes any function always return a boolean.
The final value is the negation of the value returned by the function.

!function bool() { return false; }() // true
!function bool() { return true; }() // false

Omitting ! in the above examples would be a SyntaxError.

function bool() { return true; }() // SyntaxError

However, a better way to achieve this would be:

(function bool() { return true; })() // true

How to map to multiple elements with Java 8 streams?

It's an interesting question, because it shows that there are a lot of different approaches to achieve the same result. Below I show three different implementations.


Default methods in Collection Framework: Java 8 added some methods to the collections classes, that are not directly related to the Stream API. Using these methods, you can significantly simplify the implementation of the non-stream implementation:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    Map<String, DataSet> result = new HashMap<>();
    multiDataPoints.forEach(pt ->
        pt.keyToData.forEach((key, value) ->
            result.computeIfAbsent(
                key, k -> new DataSet(k, new ArrayList<>()))
            .dataPoints.add(new DataPoint(pt.timestamp, value))));
    return result.values();
}

Stream API with flatten and intermediate data structure: The following implementation is almost identical to the solution provided by Stuart Marks. In contrast to his solution, the following implementation uses an anonymous inner class as intermediate data structure.

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .flatMap(mdp -> mdp.keyToData.entrySet().stream().map(e ->
            new Object() {
                String key = e.getKey();
                DataPoint dataPoint = new DataPoint(mdp.timestamp, e.getValue());
            }))
        .collect(
            collectingAndThen(
                groupingBy(t -> t.key, mapping(t -> t.dataPoint, toList())),
                m -> m.entrySet().stream().map(e -> new DataSet(e.getKey(), e.getValue())).collect(toList())));
}

Stream API with map merging: Instead of flattening the original data structures, you can also create a Map for each MultiDataPoint, and then merge all maps into a single map with a reduce operation. The code is a bit simpler than the above solution:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .map(mdp -> mdp.keyToData.entrySet().stream()
            .collect(toMap(e -> e.getKey(), e -> asList(new DataPoint(mdp.timestamp, e.getValue())))))
        .reduce(new HashMap<>(), mapMerger())
        .entrySet().stream()
        .map(e -> new DataSet(e.getKey(), e.getValue()))
        .collect(toList());
}

You can find an implementation of the map merger within the Collectors class. Unfortunately, it is a bit tricky to access it from the outside. Following is an alternative implementation of the map merger:

<K, V> BinaryOperator<Map<K, List<V>>> mapMerger() {
    return (lhs, rhs) -> {
        Map<K, List<V>> result = new HashMap<>();
        lhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        rhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        return result;
    };
}

Converting rows into columns and columns into rows using R

Simply use the base transpose function t, wrapped with as.data.frame:

final_df <- as.data.frame(t(starting_df))
final_df
     A    B    C    D
a    1    2    3    4
b 0.02 0.04 0.06 0.08
c Aaaa Bbbb Cccc Dddd

Above updated. As docendo discimus pointed out, t returns a matrix. As Mark suggested wrapping it with as.data.frame gets back a data frame instead of a matrix. Thanks!

How do I remove all null and empty string values from an object?

There is a very simple way to remove NULL values from JSON object. By default JSON object includes NULL values. Following can be used to remove NULL from JSON string

JsonConvert.SerializeObject(yourClassObject, new JsonSerializerSettings() {
                                       NullValueHandling = NullValueHandling.Ignore})) 

Exposing the current state name with ui router

I wrapped around $state around $timeout and it worked for me.

For example,

(function() {
  'use strict';

  angular
    .module('app')
    .controller('BodyController', BodyController);

  BodyController.$inject = ['$state', '$timeout'];

  /* @ngInject */
  function BodyController($state, $timeout) {
    $timeout(function(){
      console.log($state.current);
    });

  }
})();

How do I make Visual Studio pause after executing a console application in debug mode?

It would actually be more effort, but you could just build in VS.Net, run it from the regular command line (cmd.exe), and then attach to the process after it starts running. This is probably not the solution you are looking for however.

Background color for Tk in Python

config is another option:

widget1.config(bg='black')
widget2.config(bg='#000000')

or:

widget1.config(background='black')
widget2.config(background='#000000')

Length of array in function argument

length of an array(type int) with sizeof: sizeof(array)/sizeof(int)

Set an environment variable in git bash

If you want to set environment variables permanently in Git-Bash, you have two options:

  1. Set a regular Windows environment variable. Git-bash gets all existing Windows environment variables at startupp.

  2. Set up env variables in .bash_profile file.

.bash_profile is by default located in a user home folder, like C:\users\userName\git-home\.bash_profile. You can change the path to the bash home folder by setting HOME Windows environment variable.

.bash_profile file uses the regular Bash syntax and commands

# Export a variable in .bash_profile
export DIR=c:\dir
# Nix path style works too
export DIR=/c/dir

# And don't forget to add quotes if a variable contains whitespaces
export ANOTHER_DIR="c:\some dir"

Read more information about Bash configurations files.

ORA-12505: TNS:listener does not currently know of SID given in connect descriptor (DBD ERROR: OCIServerAttach)

You could try this.

In windows go to Administrative Tools->Services And see scroll down to where it says Oracle[instanceNameHere] and see if the listener and the service itself are running. You might have to start it. You can also set it to start automatically when you right-click on it and go to properties.

Python pandas insert list into a cell

df3.set_value(1, 'B', abc) works for any dataframe. Take care of the data type of column 'B'. Eg. a list can not be inserted into a float column, at that case df['B'] = df['B'].astype(object) can help.

Fixed header, footer with scrollable content

Something like this

<html>
  <body style="height:100%; width:100%">
    <div id="header" style="position:absolute; top:0px; left:0px; height:200px; right:0px;overflow:hidden;"> 
    </div> 
    <div id="content" style="position:absolute; top:200px; bottom:200px; left:0px; right:0px; overflow:auto;"> 
    </div> 
    <div id="footer" style="position:absolute; bottom:0px; height:200px; left:0px; right:0px; overflow:hidden;"> 
    </div>
  </body>
</html> 

HTML Button Close Window

Use the code below. It works every time.

<button onclick="self.close()">Close</button>

It works every time in Chrome and also works on Firefox.

How to call a stored procedure (with parameters) from another stored procedure without temp table

You can create table variable instead of tamp table in procedure A and execute procedure B and insert into temp table by below query.

DECLARE @T TABLE
(
TABLE DEFINITION
)
.
.
.
INSERT INTO @T
EXEC B @MYDATE

and you continue operation.

How to prevent page scrolling when scrolling a DIV element?

All you need is

e.preventDefault();

on child element.

Repeat each row of data.frame the number of times specified in a column

Here's one solution:

df.expanded <- df[rep(row.names(df), df$freq), 1:2]

Result:

    var1 var2
1      a    d
2      b    e
2.1    b    e
3      c    f
3.1    c    f
3.2    c    f

Set HTML dropdown selected option using JSTL

Real simple. You just need to have the string 'selected' added to the right option. In the following code, ${myBean.foo == val ? 'selected' : ' '} will add the string 'selected' if the option's value is the same as the bean value;

<select name="foo" id="foo" value="${myBean.foo}">
    <option value="">ALL</option>
    <c:forEach items="${fooList}" var="val"> 
        <option value="${val}" ${myBean.foo == val ? 'selected' : ' '}><c:out value="${val}" ></c:out></option>   
    </c:forEach>                     
</select>

How to recursively delete an entire directory with PowerShell 2.0?

For some reason John Rees' answer sometimes did not work in my case. But it led me in the following direction. First I try to delete the directory recursively with the buggy -recurse option. Afterwards I descend into every subdir that's left and delete all files.

function Remove-Tree($Path)
{ 
    Remove-Item $Path -force -Recurse -ErrorAction silentlycontinue

    if (Test-Path "$Path\" -ErrorAction silentlycontinue)
    {
        $folders = Get-ChildItem -Path $Path –Directory -Force
        ForEach ($folder in $folders)
        {
            Remove-Tree $folder.FullName
        }

        $files = Get-ChildItem -Path $Path -File -Force

        ForEach ($file in $files)
        {
            Remove-Item $file.FullName -force
        }

        if (Test-Path "$Path\" -ErrorAction silentlycontinue)
        {
            Remove-Item $Path -force
        }
    }
}

Call js-function using JQuery timer

jQuery 1.4 also includes a .delay( duration, [ queueName ] ) method if you only need it to trigger once and have already started using that version.

$('#foo').slideUp(300).delay(800).fadeIn(400);

http://api.jquery.com/delay/

Ooops....my mistake you were looking for an event to continue triggering. I'll leave this here, someone may find it helpful.

How to recompile with -fPIC

I hit this same issue trying to install Dashcast on Centos 7. The fix was adding -fPIC at the end of each of the CFLAGS in the x264 Makefile. Then I had to run make distclean for both x264 and ffmpeg and rebuild.

How do I bind onchange event of a TextBox using JQuery?

if you're trying to use jQuery autocomplete plugin, then I think you don't need to bind to onChange event, it will

How do I force Maven to use my local repository rather than going out to remote repos to retrieve artifacts?

The dependency has a snapshot version. For snapshots, Maven will check the local repository and if the artifact found in the local repository is too old, it will attempt to find an updated one in the remote repositories. That is probably what you are seeing.

Note that this behavior is controlled by the updatePolicy directive in the repository configuration (which is daily by default for snapshot repositories).

MVC 3 file upload and model binding

If you won't always have images posting to your action, you can do something like this:

[HttpPost]
public ActionResult Uploadfile(Container container, HttpPostedFileBase file) 
{
    //do container stuff

    if (Request.Files != null)
    {
        foreach (string requestFile in Request.Files)
        {
            HttpPostedFileBase file = Request.Files[requestFile]; 
            if (file.ContentLength > 0)
            {
                string fileName = Path.GetFileName(file.FileName);
                string directory = Server.MapPath("~/App_Data/uploads/");
                if (!Directory.Exists(directory))
                {
                    Directory.CreateDirectory(directory);
                }
                string path = Path.Combine(directory, fileName);
                file.SaveAs(path);
            }
        }
    }

} 

How to create a stopwatch using JavaScript?

well after a few modification of the code provided by mace,i ended up building a stopwatch. https://codepen.io/truestbyheart/pen/EGELmv

  <!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Stopwatch</title>
    <style>
    #center {
     margin: 30%  30%;
     font-family: tahoma;
     }
    .stopwatch {
         border:1px solid #000;
         background-color: #eee;
         text-align: center;
         width:656px;
         height: 230px;
         overflow: hidden;
     }
     .stopwatch span{
         display: block;
         font-size: 100px;
     }
     .stopwatch p{
         display: inline-block;
         font-size: 40px;
     }
     .stopwatch a{
       font-size:45px;
     }
     a:link,
     a:visited{
         color :#000;
         text-decoration: none;
         padding: 12px 14px;
         border: 1px solid #000;
     }
    </style>
  </head>
  <body>
      <div id="center">
            <div class="timer stopwatch"></div>
      </div>

    <script>
      const Stopwatch = function(elem, options) {
        let timer = createTimer(),
          startButton = createButton("start", start),
          stopButton = createButton("stop", stop),
          resetButton = createButton("reset", reset),
          offset,
          clock,
          interval,
          hrs = 0,
          min = 0;

        // default options
        options = options || {};
        options.delay = options.delay || 1;

        // append elements
        elem.appendChild(timer);
        elem.appendChild(startButton);
        elem.appendChild(stopButton);
        elem.appendChild(resetButton);

        // initialize
        reset();

        // private functions
        function createTimer() {
          return document.createElement("span");
        }

        function createButton(action, handler) {
          if (action !== "reset") {
            let a = document.createElement("a");
            a.href = "#" + action;
            a.innerHTML = action;
            a.addEventListener("click", function(event) {
              handler();
              event.preventDefault();
            });
            return a;
          } else if (action === "reset") {
            let a = document.createElement("a");
            a.href = "#" + action;
            a.innerHTML = action;
            a.addEventListener("click", function(event) {
              clean();
              event.preventDefault();
            });
            return a;
          }
        }

        function start() {
          if (!interval) {
            offset = Date.now();
            interval = setInterval(update, options.delay);
          }
        }

        function stop() {
          if (interval) {
            clearInterval(interval);
            interval = null;
          }
        }

        function reset() {
          clock = 0;
          render(0);
        }

        function clean() {
          min = 0;
          hrs = 0;
          clock = 0;
          render(0);
        }

        function update() {
          clock += delta();
          render();
        }

        function render() {
          if (Math.floor(clock / 1000) === 60) {
            min++;
            reset();
            if (min === 60) {
              min = 0;
              hrs++;
            }
          }
          timer.innerHTML =
            hrs + "<p>hrs</p>" + min + "<p>min</p>" + Math.floor(clock / 1000)+ "<p>sec</p>";
        }

        function delta() {
          var now = Date.now(),
            d = now - offset;

          offset = now;
          return d;
        }
      };

      // Initiating the Stopwatch
      var elems = document.getElementsByClassName("timer");

      for (var i = 0, len = elems.length; i < len; i++) {
        new Stopwatch(elems[i]);
      }
    </script>
  </body>
</html>

Distinct pair of values SQL

This will give you the result you're giving as an example:

SELECT DISTINCT a, b
FROM pairs

How to use mouseover and mouseout in Angular 6

CSS solution works without a glitch!

https://www.w3schools.com/code/tryit.asp?filename=GJ4PCJMVQ4LN https://www.w3schools.com/code/tryit.asp?filename=GJ4PPLCCEBRG

_x000D_
_x000D_
.col-info:hover>.popoverIcon {
    visibility: visible;
  }
}

.popoverIcon {
  visibility: hidden;
}
_x000D_
<div *ngFor="let i of [1,2,3,4]">

  <div class="col-info">
    <span class=" popoverIcon ">Show {{i}}</span>
  </div>

</div>
_x000D_
_x000D_
_x000D_

How do I URl encode something in Node.js?

The built-in module querystring is what you're looking for:

var querystring = require("querystring");
var result = querystring.stringify({query: "SELECT name FROM user WHERE uid = me()"});
console.log(result);
#prints 'query=SELECT%20name%20FROM%20user%20WHERE%20uid%20%3D%20me()'

Advantages of using display:inline-block vs float:left in CSS

If you want to align the div with pixel accurate, then use float. inline-block seems to always requires you to chop off a few pixels (at least in IE)

Removing all unused references from a project in Visual Studio projects

For anybody coming here looking for Visual studio 2012:

Download and Install Reference Assistant for Visual Studio 11

Later you can do:

enter image description here

How should you diagnose the error SEHException - External component has thrown an exception

Just another information... Had that problem today on a Windows 2012 R2 x64 TS system where the application was started from a unc/network path. The issue occured for one application for all terminal server users. Executing the application locally worked without problems. After a reboot it started working again - the SEHException's thrown had been Constructor init and TargetInvocationException

How to set a default value with Html.TextBoxFor?

This should work for MVC3 & MVC4

 @Html.TextBoxFor(m => m.Age, new { @Value = "12" }) 

If you want it to be a hidden field

 @Html.TextBoxFor(m => m.Age, new { @Value = "12",@type="hidden" }) 

How to write URLs in Latex?

You just need to escape characters that have special meaning: # $ % & ~ _ ^ \ { }

So

http://stack_overflow.com/~foo%20bar#link

would be

http://stack\_overflow.com/\~foo\%20bar\#link

How do you get the contextPath from JavaScript, the right way?

I think you can achieve what you are looking for by combining number 1 with calling a function like in number 3.

You don't want to execute scripts on page load and prefer to call a function later on? Fine, just create a function that returns the value you would have set in a variable:

function getContextPath() {
   return "<%=request.getContextPath()%>";
}

It's a function so it wont be executed until you actually call it, but it returns the value directly, without a need to do DOM traversals or tinkering with URLs.

At this point I agree with @BalusC to use EL:

function getContextPath() {
   return "${pageContext.request.contextPath}";
}

or depending on the version of JSP fallback to JSTL:

function getContextPath() {
   return "<c:out value="${pageContext.request.contextPath}" />";
}

Sort a Map<Key, Value> by values

Okay, this version works with two new Map objects and two iterations and sorts on values. Hope, the performs well although the map entries must be looped twice:

public static void main(String[] args) {
    Map<String, String> unsorted = new HashMap<String, String>();
    unsorted.put("Cde", "Cde_Value");
    unsorted.put("Abc", "Abc_Value");
    unsorted.put("Bcd", "Bcd_Value");

    Comparator<String> comparer = new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {
            return o1.compareTo(o2);
        }};

    System.out.println(sortByValue(unsorted, comparer));

}

public static <K, V> Map<K,V> sortByValue(Map<K, V> in, Comparator<? super V> compare) {
    Map<V, K> swapped = new TreeMap<V, K>(compare);
    for(Entry<K,V> entry: in.entrySet()) {
        if (entry.getValue() != null) {
            swapped.put(entry.getValue(), entry.getKey());
        }
    }
    LinkedHashMap<K, V> result = new LinkedHashMap<K, V>();
    for(Entry<V,K> entry: swapped.entrySet()) {
        if (entry.getValue() != null) {
            result.put(entry.getValue(), entry.getKey());
        }
    }
    return result;
}

The solution uses a TreeMap with a Comparator and sorts out all null keys and values. First, the ordering functionality from the TreeMap is used to sort upon the values, next the sorted Map is used to create a result as a LinkedHashMap that retains has the same order of values.

Greetz, GHad

How to compare pointers?

Yes, that is the definition of raw pointer equality: they both point to the same location (or are pointer aliases); usually in the virtual address space of the process running your application coded in C++ and managed by some operating system (but C++ can also be used for programming embedded devices with micro-controllers having a Harward architecture: on such microcontrollers some pointer casts are forbidden and makes no sense - since read only data could sit in code ROM)

For C++, read a good C++ programming book, see this C++ reference website, read the documentation of your C++ compiler (perhaps GCC or Clang) and consider coding with smart pointers. Maybe read also some draft C++ standard, like n4713 or buy the official standard from your ISO representative.

The concepts and terminology of garbage collection are also relevant when managing pointers and memory zones obtained by dynamic allocation (e.g. ::operator new), so read perhaps the GC handbook.

For pointers on Linux machines, see also this.

How to fix height of TR?

Your table width is 90% which is relative to it's container.

If you squeeze the page, you are probably squeezing the table width as well. The width of the cells reduce too and the browser compensate by increasing the height.

To have the height untouched, you have to make sure the widths of the cells can hold the intented content. Fixing the table width is probably something you want to try. Or perhaps play around with the min-width of the table.

JQuery, select first row of table

Ok so if an image in a table is clicked you want the data of the first row of the table this image is in.

//image click stuff here {
$(this). // our image
closest('table'). // Go upwards through our parents untill we hit the table
children('tr:first'); // Select the first row we find

var $row = $(this).closest('table').children('tr:first');

parent() will only get the direct parent, closest should do what we want here. From jQuery docs: Get the first ancestor element that matches the selector, beginning at the current element and progressing up through the DOM tree.

convert float into varchar in SQL server without scientific notation

None of the above worked for me. In the end I simply used this:

INSERT INTO [Destination_Table_Name]([Field_Name])
SELECT  CONCAT('#',CAST([Field_Name] AS decimal(38,0))) [Field_Name] 
FROM [dbo].[Source_Table_Name] WHERE ISNUMERIC([CIRCUIT_NUMBER]) = 1
 
INSERT INTO [Destination_Table_Name]([Field_Name])
SELECT  [Field_Name]
FROM [dbo].[Source_Table_Name] WHERE ISNUMERIC([CIRCUIT_NUMBER]) <> 1

What is the purpose of "pip install --user ..."?

Other answers mention site.USER_SITE as where Python packages get placed. If you're looking for binaries, these go in {site.USER_BASE}/bin.

If you want to add this directory to your shell's search path, use:

export PATH="${PATH}:$(python3 -c 'import site; print(site.USER_BASE)')/bin"

How to select an element with 2 classes

Just chain them together:

.a.b {
  color: #666;
}

Convert JSON string to dict using Python

json.loads()

import json

d = json.loads(j)
print d['glossary']['title']

Android intent for playing video?

Use setDataAndType on the Intent

Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse(newVideoPath), "video/mp4");
startActivity(intent);

Use "video/mp4" as MIME or use "video/*" if you don't know the type.

Can't start hostednetwork

Symptoms
You install an application that uses Microsoft Virtual WiFi technology on a computer that is running Windows 7 or Windows Server 2008 R2. However, the application does not work after the computer restarts. Additionally, you receive an error message that resembles the following:

The hosted network couldn't be started. The group or resource is not in the correct state to perform the requested operation.

Cause
This issue occurs because the Virtual Wi-Fi filter driver does not create the Virtual Wi-Fi Adapter correctly when a PNP resource rebalance occurs during the startup process.

Notes
1.This issue may occur when a Plug and Play (PNP) resource rebalance occurs during the startup process. The PNP resource rebalance is usually triggered by a change to the hardware configuration.
2.If you open Device Manager when this issue occurs, you notice that the Virtual WiFi Adapter is not created.

If you can't restart your hostednetwork after rebooting the OS ,just Try this hotfix .It fixed my problem. Or try to figure it out by yourself according to the Symptoms and Cause mentioned at the start of my answer.

Why does C# XmlDocument.LoadXml(string) fail when an XML header is included?

I had the same issue because the XML file I was uploading was encoded using UTF-8-BOM (UTF-8 byte-order mark).

Switched the encoding to UTF-8 in Notepad++ and was able to load the XML file in code.

Extend contigency table with proportions (percentages)

Your code doesn't seem so ugly to me...
however, an alternative (not much better) could be e.g. :

df <- data.frame(table(yn))
colnames(df) <- c('Smoker','Freq')
df$Perc <- df$Freq / sum(df$Freq) * 100

------------------
  Smoker Freq Perc
1     No   19 47.5
2    Yes   21 52.5

How to redirect page after click on Ok button on sweet alert?

To specify a callback function, you have to use an object as the first argument, and the callback function as the second argument.

echo '<script>
    setTimeout(function() {
        swal({
            title: "Wow!",
            text: "Message!",
            type: "success"
        }, function() {
            window.location = "redirectURL";
        });
    }, 1000);
</script>';

Excel formula to get week number in month (having Monday)

Jonathan from the ExcelCentral forums suggests:

=WEEKNUM(A1,2)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),2)+1 

This formula extracts the week of the year [...] and then subtracts it from the week of the first day in the month to get the week of the month. You can change the day that weeks begin by changing the second argument of both WEEKNUM functions (set to 2 [for Monday] in the above example). For weeks beginning on Sunday, use:

=WEEKNUM(A1,1)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),1)+1

For weeks beginning on Tuesday, use:

=WEEKNUM(A1,12)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),12)+1

etc.

I like it better because it's using the built in week calculation functionality of Excel (WEEKNUM).

Remove Last Comma from a string

Remove last comma. Working example

_x000D_
_x000D_
function truncateText() {_x000D_
  var str= document.getElementById('input').value;_x000D_
  str = str.replace(/,\s*$/, "");_x000D_
  console.log(str);_x000D_
}
_x000D_
<input id="input" value="address line one,"/>_x000D_
<button onclick="truncateText()">Truncate</button>
_x000D_
_x000D_
_x000D_

How to pop an alert message box using PHP?

You could use Javascript:

// This is in the PHP file and sends a Javascript alert to the client
$message = "wrong answer";
echo "<script type='text/javascript'>alert('$message');</script>";

Python Library Path

I think you're looking for sys.path

import sys
print (sys.path)

How to enable Ad Hoc Distributed Queries

The following command may help you..

EXEC sp_configure 'show advanced options', 1
RECONFIGURE
GO
EXEC sp_configure 'ad hoc distributed queries', 1
RECONFIGURE
GO

Angular2 QuickStart npm start is not working correctly

I solved my issue with the Quick Start program by following below link.

Angular 2 QuickStart Live-server error

Change the Package.json Scripts Settings

"start": "tsc && concurrently \"npm run tsc:w\" \"npm run lite\",

to:

"start": "concurrently \"npm run tsc:w\" \"npm run lite\" ",

Aligning a float:left div to center?

CSS Flexbox is well supported these days. Go here for a good tutorial on flexbox.

This works fine in all newer browsers:

_x000D_
_x000D_
#container {_x000D_
  display:         flex;_x000D_
  flex-wrap:       wrap;_x000D_
  justify-content: center;_x000D_
}_x000D_
_x000D_
.block {_x000D_
  width:              150px;_x000D_
  height:             150px;_x000D_
  background-color:   #cccccc;_x000D_
  margin:             10px;        _x000D_
}
_x000D_
<div id="container">_x000D_
  <div class="block">1</div>    _x000D_
  <div class="block">2</div>    _x000D_
  <div class="block">3</div>    _x000D_
  <div class="block">4</div>    _x000D_
  <div class="block">5</div>        _x000D_
</div>
_x000D_
_x000D_
_x000D_

Some may ask why not use display: inline-block? For simple things it is fine, but if you got complex code within the blocks, the layout may not be correctly centered anymore. Flexbox is more stable than float left.

Failed to authenticate on SMTP server error using gmail

This is how I solved this issue:

  1. Change the .env file as follow

Screenshot Reference

  1. Never forget to restart the server after you change the .env file

Sending emails with Javascript

The problem with the very idea is that the user has to have an email client, which is not the case if he rely on webmails, which is the case for many users. (at least there was no turn-around to redirect to this webmail when I investigated the issue a dozen years ago).

That's why the normal solution is to rely on php mail() for sending emails (server-side, then).

But if nowadays "email client" is always set, automatically, potentially to a webmail client, I'll be happy to know.

VBA to copy a file from one directory to another

This method is even easier if you're ok with fewer options:

FileCopy source, destination

How to document a method with parameter(s)?

Conventions:

Tools:


Update: Since Python 3.5 you can use type hints which is a compact, machine-readable syntax:

from typing import Dict, Union

def foo(i: int, d: Dict[str, Union[str, int]]) -> int:
    """
    Explanation: this function takes two arguments: `i` and `d`.
    `i` is annotated simply as `int`. `d` is a dictionary with `str` keys
    and values that can be either `str` or `int`.

    The return type is `int`.

    """

The main advantage of this syntax is that it is defined by the language and that it's unambiguous, so tools like PyCharm can easily take advantage from it.

Hiding a form and showing another when a button is clicked in a Windows Forms application

To link to a form you need:

Form2 form2 = new Form2();
        form2.show();

this.hide();

then hide the previous form

program cant start because php5.dll is missing

I had the same problem I switched from wamp to xampp and yes PHP was working because my path was still pointing to my old installation. I had forgotten to change it to point to my new php installation which version of php didn't match the rest at all.

Library not loaded: libmysqlclient.16.dylib error when trying to run 'rails server' on OS X 10.6 with mysql2 gem

This fix worked very well for me:

Add the following to to your ~/.profile

export DYLD_LIBRARY_PATH=/usr/local/mysql/lib:$DYLD_LIBRARY_PATH

http://www.rickwargo.com/2010/12/16/installing-mysql-5-5-on-os-x-10-6-snow-leopard-and-rails-3/

How to return dictionary keys as a list in Python?

If you need to store the keys separately, here's a solution that requires less typing than every other solution presented thus far, using Extended Iterable Unpacking (python3.x+).

newdict = {1: 0, 2: 0, 3: 0}
*k, = newdict

k
# [1, 2, 3]

            +---------------------------------------------------------+
            ¦ k = list(d)   ¦   9 characters (excluding whitespace)   ¦
            +---------------+-----------------------------------------¦
            ¦ k = [*d]      ¦   6 characters                          ¦
            +---------------+-----------------------------------------¦
            ¦ *k, = d       ¦   5 characters                          ¦
            +---------------------------------------------------------+

How do you allow spaces to be entered using scanf?

You can use the fgets() function to read a string or use scanf("%[^\n]s",name); so string reading will terminate upon encountering a newline character.

HTML Image not displaying, while the src url works

It wont work since you use URL link with "file://". Instead you should match your directory to your HTML file, for example:

Lets say my file placed in:

C:/myuser/project/file.html

And my wanted image is in:

C:/myuser/project2/image.png

All I have to do is matching the directory this way:

<img src="../project2/image.png" />

Creating a jQuery object from a big HTML-string

Update:

From jQuery 1.8, we can use $.parseHTML, which will parse the HTML string to an array of DOM nodes. eg:

var dom_nodes = $($.parseHTML('<div><input type="text" value="val" /></div>'));

alert( dom_nodes.find('input').val() );

DEMO


var string = '<div><input type="text" value="val" /></div>';

$('<div/>').html(string).contents();

DEMO

What's happening in this code:

  • $('<div/>') is a fake <div> that does not exist in the DOM
  • $('<div/>').html(string) appends string within that fake <div> as children
  • .contents() retrieves the children of that fake <div> as a jQuery object

If you want to make .find() work then try this:

var string = '<div><input type="text" value="val" /></div>',
    object = $('<div/>').html(string).contents();

alert( object.find('input').val() );

DEMO

How can you make a custom keyboard in Android?

Well Suragch gave the best answer so far but he skipped certain minor stuff that was important to getting the app compiled.

I hope to make a better answer than Suragch by improving on his answer. I will add all the missing elements he didnt put.

I compiled my apk using the android app , APK Builder 1.1.0. So let's begin.

To build an Android app we need couple files and folders that are organized in a certain format and capitalized accordingly.

res layout -> xml files depicting how app will look on phone. Similar to how html shapes how web page looks on browser. Allowing your app to fit on screens accordingly.

values -> constant data such as colors.xml, strings.xml, styles.xml. These files must be properly spelt.

drawable -> pics{jpeg, png,...}; Name them anything.

mipmap -> more pics. used for app icon?

xml -> more xml files.

src -> acts like JavaScript in html. layout files will initiate the starting view and your java file will dynamically control the tag elements and trigger events. Events can also be activated directly in the layout.xml just like in html.

AndroidManifest.xml -> This file registers what your app is about. Application name, Type of program, permissions needed, etc. This seems to make Android rather safe. Programs literally cannot do what they didnt ask for in the Manifest.

Now there are 4 types of Android programs, an activity, a service, a content provider, and a broadcast reciever. Our keyboard will be a service, which allows it to run in the background. It will not appear in the list of apps to launch; but it can be uninstalled.

To compile your app, involves gradle, and apk signing. You can research that one or use APK Builder for android. It is super easy.

Now that we understand Android development, let us create the files and folders.

  1. Create the files and folders as I discussed above. My directory wil look as follows:

    • NumPad
      • AndroidManifest.xml
      • src
        • Saragch
          • num_pad
            • MyInputMethodService.java
      • res
        • drawable
          • Suragch_NumPad_icon.png
        • layout
          • key_preview.xml
          • keyboard_view.xml
        • xml
          • method.xml
          • number_pad.xml
        • values
          • colors.xml
          • strings.xml
          • styles.xml

Remember if you are using an ide such as Android Studio it may have a project file.

  1. Write files.

A: NumPad/res/layout/key_preview.xml

<?xml version="1.0" encoding="utf-8"?>
   <TextView
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:gravity="center"
      android:background="@android:color/white"
      android:textColor="@android:color/black"
      android:textSize="30sp">
</TextView>

B: NumPad/res/layout/keyboard_view.xml

<?xml version="1.0" encoding="utf-8"?>
<android.inputmethodservice.KeyboardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/keyboard_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:keyPreviewLayout="@layout/key_preview"
    android:layout_alignParentBottom="true">

</android.inputmethodservice.KeyboardView>

C: NumPad/res/xml/method.xml

<?xml version="1.0" encoding="utf-8"?>
<input-method  xmlns:android="http://schemas.android.com/apk/res/android">
    <subtype  android:imeSubtypeMode="keyboard"/>
</input-method>

D: Numpad/res/xml/number_pad.xml

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:keyWidth="20%p"
    android:horizontalGap="5dp"
    android:verticalGap="5dp"
    android:keyHeight="60dp">

    <Row>
        <Key android:codes="49" android:keyLabel="1" android:keyEdgeFlags="left"/>
        <Key android:codes="50" android:keyLabel="2"/>
        <Key android:codes="51" android:keyLabel="3"/>
        <Key android:codes="52" android:keyLabel="4"/>
        <Key android:codes="53" android:keyLabel="5" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="54" android:keyLabel="6" android:keyEdgeFlags="left"/>
        <Key android:codes="55" android:keyLabel="7"/>
        <Key android:codes="56" android:keyLabel="8"/>
        <Key android:codes="57" android:keyLabel="9"/>
        <Key android:codes="48" android:keyLabel="0" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="-5"
             android:keyLabel="DELETE"
             android:keyWidth="40%p"
             android:keyEdgeFlags="left"
             android:isRepeatable="true"/>
        <Key android:codes="10"
             android:keyLabel="ENTER"
             android:keyWidth="60%p"
             android:keyEdgeFlags="right"/>
    </Row>

</Keyboard>

Of course this can be easily edited to your liking. You can even use images instead lf words for the label.

Suragch didnt demonstrate the files in the values folder and assumed we had access to Android Studio; which automatically creates them. Good thing I have APK Builder.

E: NumPad/res/values/colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
</resources>

F: NumPad/res/values/strings.xml

<resources>
    <string name="app_name">Suragch NumPad</string>
</resources>

G: NumPad/res/values/styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="android:Theme.Material.Light.DarkActionBar">
        <!-- Customize your theme here. -->
    </style>

</resources>

H: Numpad/AndroidManifest.xml

This is the file that was really up for contension. Here I felt I would never compile my program. sob. sob. If you check Suracgh's answer you see he leaves the first set of fields empty, and adds the activity tag in this file. As I said there are four types of Android programs. An activity is a regular app with a launcher icon. This numpad is not an activity! Further he didnt implement any activity.

My friends do not include the activity tag. Your program will compile, and when you try to launch it will crash! As for xmlns:android and uses-sdk; I cant help you there. Just try my settings if they work.

As you can see there is a service tag, which register it as a service. Also service.android:name must be name of public class extending service in our java file. It MUST be capitalized accordingly. Also package is the name of the package we declared in java file.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="Saragch.num_pad">

    <uses-sdk
        android:minSdkVersion="12"
        android:targetSdkVersion="27" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/Suragch_NumPad_icon"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <service
            android:name=".MyInputMethodService"
            android:label="Keyboard Display Name"
            android:permission="android.permission.BIND_INPUT_METHOD">

            <intent-filter>
                <action android:name="android.view.InputMethod"/>
            </intent-filter>

            <meta-data
                android:name="android.view.im"
                android:resource="@xml/method"/>

        </service>

    </application>
</manifest>

I: NumPad/src/Saragch/num_pad/MyInputMethodService.java

Note: I think java is an alternative to src.

This was another problem file but not as contentious as the manifest file. As I know Java good enough to know what is what, what is not. I barely know xml and how it ties in with Android development!

The problem here was he didnt import anything! I mean, he gave us a "complete" file which uses names that couldnt be resolved! InputMethodService, Keyboard, etc. That is bad practice Mr. Suragch. Thanks for helping me out but how did you expect the code to compile if the names cant be resolved?

Following is the correctly edited version. I just happened to pounce upon couple hints to drove me to the right place to learn what exactly to import.

package Saragch.num_pad;

import android.inputmethodservice.InputMethodService;
import android.inputmethodservice.KeyboardView;
import android.inputmethodservice.Keyboard;

import android.text.TextUtils;
import android.view.inputmethod.InputConnection;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;


public class MyInputMethodService extends InputMethodService implements KeyboardView.OnKeyboardActionListener 
{
    @Override
    public View onCreateInputView() 
    {
     // get the KeyboardView and add our Keyboard layout to it
     KeyboardView keyboardView = (KeyboardView)getLayoutInflater().inflate(R.layout.keyboard_view, null);
     Keyboard keyboard = new Keyboard(this, R.xml.number_pad);
     keyboardView.setKeyboard(keyboard);
     keyboardView.setOnKeyboardActionListener(this);
     return keyboardView;
    }

    @Override
    public void onKey(int primaryCode, int[] keyCodes) 
    {

        InputConnection ic = getCurrentInputConnection();

        if (ic == null) return;

        switch (primaryCode)
        {
         case Keyboard.KEYCODE_DELETE:
            CharSequence selectedText = ic.getSelectedText(0);

            if (TextUtils.isEmpty(selectedText)) 
            {
             // no selection, so delete previous character
             ic.deleteSurroundingText(1, 0);
            }

            else 
            {
             // delete the selection
             ic.commitText("", 1);
            }

            ic.deleteSurroundingText(1, 0);
            break;

         default:
            char code = (char) primaryCode;
            ic.commitText(String.valueOf(code), 1);
        }
    }

    @Override
    public void onPress(int primaryCode) { }

    @Override
    public void onRelease(int primaryCode) { }

    @Override
    public void onText(CharSequence text) { }

    @Override
    public void swipeLeft() { }

    @Override
    public void swipeRight() { }

    @Override
    public void swipeDown() { }

    @Override
    public void swipeUp() { }
}
  1. Compile and sign your project.

    This is where I am clueless as a newby Android developer. I would like to learn it manually, as I believe real programmers can compile manually.

I think gradle is one of the tools for compiling and packaging to apk. apk seems to be like a jar file or a rar for zip file. There are then two types of signing. debug key which is not alllowed on play store and private key.

Well lets give Mr. Saragch a hand. And thank you for watching my video. Like, subscribe.

WARNING: Setting property 'source' to 'org.eclipse.jst.jee.server:appname' did not find a matching property

Despite this question being rather old, I had to deal with a similar warning and wanted to share what I found out.

First of all this is a warning and not an error. So there is no need to worry too much about it. Basically it means, that Tomcat does not know what to do with the source attribute from context.

This source attribute is set by Eclipse (or to be more specific the Eclipse Web Tools Platform) to the server.xml file of Tomcat to match the running application to a project in workspace.

Tomcat generates a warning for every unknown markup in the server.xml (i.e. the source attribute) and this is the source of the warning. You can safely ignore it.

Delaying a jquery script until everything else has loaded

Multiple $(document).ready() will fire in order top down on the page. The last $(document).ready() will fire last on the page. Inside the last $(document).ready(), you can trigger a new custom event to fire after all the others..

Wrap your code in an event handler for the new custom event.

<html>
<head>
<script>
    $(document).on("my-event-afterLastDocumentReady", function () {
        // Fires LAST
    });
    $(document).ready(function() {
        // Fires FIRST
    });
    $(document).ready(function() {
        // Fires SECOND
    });
    $(document).ready(function() {
        // Fires THIRD
    });
</script>
<body>
... other code, scripts, etc....
</body>
</html>

<script>
    $(document).ready(function() {
        // Fires FOURTH
        // This event will fire after all the other $(document).ready() functions have completed.
        // Usefull when your script is at the top of the page, but you need it run last
        $(document).trigger("my-event-afterLastDocumentReady");
    });
</script>

How to animate RecyclerView items when they appear

A good place to start is this: https://github.com/wasabeef/recyclerview-animators/blob/master/animators/src/main/java/jp/wasabeef/recyclerview/adapters/AnimationAdapter.java

You don't even need the full library, that class is enough. Then if you just implement your Adapter class giving an animator like this:

@Override
protected Animator[] getAnimators(View view) {
    return new Animator[]{
            ObjectAnimator.ofFloat(view, "translationY", view.getMeasuredHeight(), 0)
    };
}

@Override
public long getItemId(final int position) {
    return getWrappedAdapter().getItemId(position);
}

you'll see items appearing from the bottom as they scroll, also avoiding the problem with the fast scroll.

SSH to Elastic Beanstalk instance

I have been playing with this as well.

  1. goto your elastic beanstalk service tab
  2. on your application overview goto action --> edit configuration
  3. add the name of a key as it appears in your EC2 tab (for the same region) to the existing keypair box and hit apply changes

The service will be relaunched so make a coffee for 5 mins

On your ec2 tab for the same region you'll see your new running instance. ssh to the public dns name as ec2-user using the key added in 3 e.g. ssh [email protected]

Gradle error: could not execute build using gradle distribution

As per answer by WarrenFaith, go to:

Settings -> Gradle -> Project-level settings

Change to Use customizable gradle wrapper.

Click OK and watch it build. If you still get an error at that stage, go back to:

Settings -> Gradle -> Project-level settings 

Change it back to Use default gradle wrapper (recommended)

Click OK. That fixed it for me.

jQuery check if it is clicked or not

Using jQuery, I would suggest a shorter solution.

var elementClicked;
$("element").click(function(){
   elementClicked = true;
});
if( elementClicked != true ) {
    alert("element not clicked");
}else{
    alert("element clicked");
}

("element" here is to be replaced with the actual name tag)

How do I output an ISO 8601 formatted string in JavaScript?

Almost every to-ISO method on the web drops the timezone information by applying a convert to "Z"ulu time (UTC) before outputting the string. Browser's native .toISOString() also drops timezone information.

This discards valuable information, as the server, or recipient, can always convert a full ISO date to Zulu time or whichever timezone it requires, while still getting the timezone information of the sender.

The best solution I've come across is to use the Moment.js javascript library and use the following code:

To get the current ISO time with timezone information and milliseconds

now = moment().format("YYYY-MM-DDTHH:mm:ss.SSSZZ")
// "2013-03-08T20:11:11.234+0100"

now = moment().utc().format("YYYY-MM-DDTHH:mm:ss.SSSZZ")
// "2013-03-08T19:11:11.234+0000"

now = moment().utc().format("YYYY-MM-DDTHH:mm:ss") + "Z"
// "2013-03-08T19:11:11Z" <- better use the native .toISOString() 

To get the ISO time of a native JavaScript Date object with timezone information but without milliseconds

var current_time = Date.now();
moment(current_time).format("YYYY-MM-DDTHH:mm:ssZZ")

This can be combined with Date.js to get functions like Date.today() whose result can then be passed to moment.

A date string formatted like this is JSON compilant, and lends itself well to get stored into a database. Python and C# seem to like it.

Excel VBA function to print an array to the workbook

On the same theme as other answers, keeping it simple

Sub PrintArray(Data As Variant, Cl As Range)
    Cl.Resize(UBound(Data, 1), UBound(Data, 2)) = Data
End Sub


Sub Test()
    Dim MyArray() As Variant

    ReDim MyArray(1 To 3, 1 To 3) ' make it flexible

    ' Fill array
    '  ...

    PrintArray MyArray, ActiveWorkbook.Worksheets("Sheet1").[A1]
End Sub

jQuery ui dialog change title after load-callback

I have found simpler solution:

$('#clickToCreate').live('click', function() {
     $('#yourDialogId')
         .dialog({
              title: "Set the title to Create"
         })
         .dialog('open'); 
});


$('#clickToEdit').live('click', function() {
     $('#yourDialogId')
         .dialog({
              title: "Set the title To Edit"
         })
         .dialog('open'); 
});

Hope that helps!

NoSQL Use Case Scenarios or WHEN to use NoSQL

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

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

  2. Query on large data set

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

  3. Disk I/O bottleneck

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

The definitive guide to form-based website authentication

I dont't know whether it was best to answer this as an answer or as a comment. I opted for the first option.

Regarding the poing PART IV: Forgotten Password Functionality in the first answer, I would make a point about Timing Attacks.

In the Remember your password forms, an attacker could potentially check a full list of emails and detect which are registered to the system (see link below).

Regarding the Forgotten Password Form, I would add that it is a good idea to equal times between successful and unsucessful queries with some delay function.

https://crypto.stanford.edu/~dabo/papers/webtiming.pdf

Populating Spring @Value during Unit Test

@ExtendWith(SpringExtension.class)    // @RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(initializers = ConfigDataApplicationContextInitializer.class)

May that could help. The key is ConfigDataApplicationContextInitializer get all props datas

Java string to date conversion

While some of the answers are technically correct, they are not advisable.

  • The java.util.Date & Calendar classes are notoriously troublesome. Because of flaws in design and implementation, avoid them. Fortunately we have our choice of two other excellent date-time libraries:
    • Joda-Time
      This popular open-source free-of-cost library can be used across several versions of Java. Many examples of its usage may be found on StackOverflow. Reading some of these will help get you up to speed quickly.
    • java.time.* package
      This new set of classes are inspired by Joda-Time and defined by JSR 310. These classes are built into Java 8. A project is underway to backport these classes to Java 7, but that backporting is not backed by Oracle.
  • As Kristopher Johnson correctly noted in his comment on the question, the other answers ignore vital issues of:
    • Time of Day
      Date has both a date portion and a time-of-day portion)
    • Time Zone
      The beginning of a day depends on the time zone. If you fail to specify a time zone, the JVM's default time zone is applied. That means the behavior of your code may change when run on other computers or with a modified time zone setting. Probably not what you want.
    • Locale
      The Locale's language specifies how to interpret the words (name of month and of day) encountered during parsing. (The answer by BalusC handles this properly.) Also, the Locale affects the output of some formatters when generating a string representation of your date-time.

Joda-Time

A few notes about Joda-Time follow.

Time Zone

In Joda-Time, a DateTime object truly knows its own assigned time zone. This contrasts the java.util.Date class which seems to have a time zone but does not.

Note in the example code below how we pass a time zone object to the formatter which parses the string. That time zone is used to interpret that date-time as having occurred in that time zone. So you need to think about and determine the time zone represented by that string input.

Since you have no time portion in your input string, Joda-Time assigns the first moment of the day of the specified time zone as the time-of-day. Usually this means 00:00:00 but not always, because of Daylight Saving Time (DST) or other anomalies. By the way, you can do the same to any DateTime instance by calling withTimeAtStartOfDay.

Formatter Pattern

The characters used in a formatter's pattern are similar in Joda-Time to those in java.util.Date/Calendar but not exactly the same. Carefully read the doc.

Immutability

We usually use the immutable classes in Joda-Time. Rather than modify an existing Date-Time object, we call methods that create a new fresh instance based on the other object with most aspects copied except where alterations were desired. An example is the call to withZone in last line below. Immutability helps to make Joda-Time very thread-safe, and can also make some work more clear.

Conversion

You will need java.util.Date objects for use with other classes/framework that do not know about Joda-Time objects. Fortunately, it is very easy to move back and forth.

Going from a java.util.Date object (here named date) to Joda-Time DateTime…

org.joda.time.DateTime dateTime = new DateTime( date, timeZone );

Going the other direction from Joda-Time to a java.util.Date object…

java.util.Date date = dateTime.toDate();

Sample Code

String input = "January 2, 2010";

java.util.Locale locale = java.util.Locale.US;
DateTimeZone timeZone = DateTimeZone.forID( "Pacific/Honolulu" ); // Arbitrarily chosen for example.
DateTimeFormatter formatter = DateTimeFormat.forPattern( "MMMM d, yyyy" ).withZone( timeZone ).withLocale( locale );
DateTime dateTime = formatter.parseDateTime( input );

System.out.println( "dateTime: " + dateTime );
System.out.println( "dateTime in UTC/GMT: " + dateTime.withZone( DateTimeZone.UTC ) );

When run…

dateTime: 2010-01-02T00:00:00.000-10:00
dateTime in UTC/GMT: 2010-01-02T10:00:00.000Z

How can I remove item from querystring in asp.net using c#?

Parse Querystring into a NameValueCollection. Remove an item. And use the toString to convert it back to a querystring.

using System.Collections.Specialized;

NameValueCollection filteredQueryString = System.Web.HttpUtility.ParseQueryString(Request.QueryString.ToString());
filteredQueryString.Remove("appKey");

var queryString = '?'+ filteredQueryString.ToString();

Sending intent to BroadcastReceiver from adb

As many already noticed, the problem manifests itself only if the extra string contains whitespaces.

The root cause is that OP's host OS/shell (i.e. Windows/cmd.exe) mangles the entered command - the " characters get lost, --es sms_body "test from adb" becomes --es sms_body test from adb. Which results in sms_body string extra getting assigned the value of test and the rest of the string becoming <URI>|<PACKAGE>|<COMPONENT> specifier.

To avoid all that you could use:

adb shell "am broadcast -a com.whereismywifeserver.intent.TEST --es sms_body 'test from adb' -n com.whereismywifeserver/.IntentReceiver"

or just start the interactive adb shell session first and run the am broadcast command from inside of it.

Why I get 'list' object has no attribute 'items'?

You have a dictionary within a list. You must first extract the dictionary from the list and then process the items in the dictionary.

If your list contained multiple dictionaries and you wanted the value from each dictionary stored in a list as you have shown do this:

result_list = [[int(v) for k,v in d.items()] for d in qs]

Which is the same as:

result_list = []
for d in qs:
    result_list.append([int(v) for k,v in d.items()])

The above will keep the values from each dictionary in their own separate list. If you just want all the values in one big list you can do this:

result_list = [int(v) for d in qs for k,v in d.items()]

How to convert a multipart file to File?

Although the accepted answer is correct but if you are just trying to upload your image to cloudinary, there's a better way:

Map upload = cloudinary.uploader().upload(multipartFile.getBytes(), ObjectUtils.emptyMap());

Where multipartFile is your org.springframework.web.multipart.MultipartFile.

jquery Ajax call - data parameters are not being passed to MVC Controller action

In my case, if I remove the the contentType, I get the Internal Server Error.

This is what I got working after multiple attempts:

var request =  $.ajax({
    type: 'POST',
    url: '/ControllerName/ActionName' ,
    contentType: 'application/json; charset=utf-8',
    data: JSON.stringify({ projId: 1, userId:1 }), //hard-coded value used for simplicity
    dataType: 'json'
});

request.done(function(msg) {
    alert(msg);
});

request.fail(function (jqXHR, textStatus, errorThrown) {
    alert("Request failed: " + jqXHR.responseStart +"-" + textStatus + "-" + errorThrown);
});

And this is the controller code:

public JsonResult ActionName(int projId, int userId)
{
    var obj = new ClassName();

    var result = obj.MethodName(projId, userId); // variable used for readability
    return Json(result, JsonRequestBehavior.AllowGet);
}

Please note, the case of ASP.NET is little different, we have to apply JSON.stringify() to the data as mentioned in the update of this answer.

http://localhost/ not working on Windows 7. What's the problem?

Assuming there is no problem doing a lookup on localhost (to 127.0.0.1), you need to make sure your server is listening to 127.0.0.1.

netstat works in both windows an UNIX. You probably need "netstat -a" to display listeners.

How to prevent auto-closing of console after the execution of batch file

Easy, add cmd to your last line of bat, BUT! if you reset or clear your system path, you must start your cmd with the full path, like:

%windir%\system32\cmd.exe

For example, I have a bat file to reset jdk to old version like this:

PATH=C:\Program Files\Java\jdk1.6.0_45\bin;C:\apache-ant-1.7.1\bin
SET JAVA_HOME=C:\Program Files\Java\jdk1.6.0_45
%windir%\system32\cmd.exe

since I reset the system path, I have to run cmd with the full path, or the system can't find cmd.exe, it will fail to run cmd, and just close the window, and you can't see the error msg.

Professional jQuery based Combobox control?

Unfortunately, the best thing I have seen is the jquery.combobox, but it doesn't really look like something I'd really want to use in my web applications. I think there are some usability issues with this control, but as a user I don't think I'd know to start typing for the dropdownlist to turn into a textbox.

I much prefer the Combo Dropdown Box, but it still has some features that I'd want and it's still in alpha. The only think I don't like about this other than its being alpha... is that once I type in the combobox, the original dropdownlist items disappear. However, maybe there is a setting for this... or maybe it could be added fairly easily.

Those are the only two options that I know of. Good luck in your search. I'd love to hear if you find one or if the second option works out for you.

concat scope variables into string in angular directive expression

I've created a working CodePen example demonstrating how to do this.

Relevant HTML:

<section ng-app="app" ng-controller="MainCtrl">
  <a href="#" ng-click="doSomething('#/path/{{obj.val1}}/{{obj.val2}}')">Click Me</a><br>
  debug: {{debug.val}}
</section>

Relevant javascript:

var app = angular.module('app', []);

app.controller('MainCtrl', function($scope) {
  $scope.obj = {
    val1: 'hello',
    val2: 'world'
  };

  $scope.debug = {
    val: ''
  };

  $scope.doSomething = function(input) {
    $scope.debug.val = input;
  };
});

How to expand/collapse a diff sections in Vimdiff?

Actually if you do Ctrl+W W, you won't need to add that extra Ctrl. Does the same thing.

You need to use a Theme.AppCompat theme (or descendant) with this activity

In my case such issue was appear when i tried to show Dialog. The problem was in context, I've use getBaseContext() which theoretically should return Activity context, but appears its not, or it return context before any Theme applied.

So I just replaced getBaseContexts() with "this", and now it work as expected.

        Dialog.showAlert(this, title, message,....);