Programs & Examples On #Zend debugger

How to use a keypress event in AngularJS?

I'm a bit late .. but i found a simpler solution using auto-focus .. This could be useful for buttons or other when popping a dialog :

<button auto-focus ng-click="func()">ok</button>

That should be fine if you want to press the button onSpace or Enter clicks .

JUnit Testing Exceptions

If your constructor is similar to this one:

public Example(String example) {
    if (example == null) {
        throw new NullPointerException();
    }
    //do fun things with valid example here
}

Then, when you run this JUnit test you will get a green bar:

@Test(expected = NullPointerException.class)
public void constructorShouldThrowNullPointerException() {
    Example example = new Example(null);
}

difference between width auto and width 100 percent

Width auto

The initial width of a block level element like div or p is auto. This makes it expand to occupy all available horizontal space within its containing block. If it has any horizontal padding or border, the widths of those do not add to the total width of the element.

Width 100%

On the other hand, if you specify width:100%, the element’s total width will be 100% of its containing block plus any horizontal margin, padding and border (unless you’ve used box-sizing:border-box, in which case only margins are added to the 100% to change how its total width is calculated). This may be what you want, but most likely it isn’t.

To visualise the difference see this picture:

enter image description here

Source

Javascript reduce() on Object

Try this one. It will sort numbers from other variables.

const obj = {
   a: 1,
   b: 2,
   c: 3
};
const result = Object.keys(obj)
.reduce((acc, rec) => typeof obj[rec] === "number" ? acc.concat([obj[rec]]) : acc, [])
.reduce((acc, rec) => acc + rec)

how to loop through json array in jquery?

Try this:

for(var i = 0; i < data.length; i++){
    console.log(data[i].com)
}

Change directory in Node.js command prompt

Type .exit in command prompt window, It terminates the node repl.

What is useState() in React?

Basically React.useState(0) magically sees that it should return the tuple count and setCount (a method to change count). The parameter useState takes sets the initial value of count.

  const [count, setCount] = React.useState(0);
  const [count2, setCount2] = React.useState(0);

  // increments count by 1 when first button clicked
  function handleClick(){
    setCount(count + 1);
  } 

  // increments count2 by 1 when second button clicked
  function handleClick2(){
    setCount2(count2 + 1);
  } 

  return (
    <div>
      <h2>A React counter made with the useState Hook!</h2>
      <p>You clicked {count} times</p>
      <p>You clicked {count2} times</p>
      <button onClick={handleClick}>
        Click me
      </button> 
      <button onClick={handleClick2}>
        Click me2
      </button>
  );

Based off Enmanuel Duran's example, but shows two counters and writes lambda functions as normal functions, so some people might understand it easier.

Twitter bootstrap collapse: change display of toggle button

I guess you could look inside your downloaded code where exactly there is a + sign (but this might not be very easy).

What I'd do? I'd find the class/id of the DOM elements that contain the + sign (suppose it's ".collapsible", and with Javascript (actually jQuery):

<script>
     $(document).ready(function() {
         var content=$(".collapsible").html().replace("+", "-");
         $(".collapsible").html(content));
     });
</script>

edit Alright... Sorry I haven't looked at the bootstrap code... but I guess it works with something like slideToggle, or slideDown and slideUp... Imagine it's a slideToggle for the elements of class .collapsible, which reveal contents of some .info elements. Then:

         $(".collapsible").click(function() { 
             var content=$(".collapsible").html();
             if $(this).next().css("display") === "none") { 
                 $(".collapsible").html(content.replace("+", "-"));
             }
             else $(".collapsible").html(content.replace("-", "+"));
         });

This seems like the opposite thing to do, but since the actual animation runs in parallel, you will check css before animation, and that's why you need to check if it's visible (which will mean it will be hidden once the animation is complete) and then set the corresponding + or -.

Putting images with options in a dropdown list

Checkout And Run The Following Code. It will help you...

_x000D_
_x000D_
 $( function() {_x000D_
    $.widget( "custom.iconselectmenu", $.ui.selectmenu, {_x000D_
      _renderItem: function( ul, item ) {_x000D_
        var li = $( "<li>" ),_x000D_
          wrapper = $( "<div>", { text: item.label } );_x000D_
 _x000D_
        if ( item.disabled ) {_x000D_
          li.addClass( "ui-state-disabled" );_x000D_
        }_x000D_
 _x000D_
        $( "<span>", {_x000D_
          style: item.element.attr( "data-style" ),_x000D_
          "class": "ui-icon " + item.element.attr( "data-class" )_x000D_
        })_x000D_
          .appendTo( wrapper );_x000D_
 _x000D_
        return li.append( wrapper ).appendTo( ul );_x000D_
      }_x000D_
    });_x000D_
 _x000D_
    $( "#filesA" )_x000D_
      .iconselectmenu()_x000D_
      .iconselectmenu( "menuWidget" )_x000D_
        .addClass( "ui-menu-icons" );_x000D_
 _x000D_
    $( "#filesB" )_x000D_
      .iconselectmenu()_x000D_
      .iconselectmenu( "menuWidget" )_x000D_
        .addClass( "ui-menu-icons customicons" );_x000D_
 _x000D_
    $( "#people" )_x000D_
      .iconselectmenu()_x000D_
      .iconselectmenu( "menuWidget")_x000D_
        .addClass( "ui-menu-icons avatar" );_x000D_
  } );_x000D_
  </script>_x000D_
  <style>_x000D_
    h2 {_x000D_
      margin: 30px 0 0 0;_x000D_
    }_x000D_
    fieldset {_x000D_
      border: 0;_x000D_
    }_x000D_
    label
_x000D_
{_x000D_
      display: block;_x000D_
    }_x000D_
 _x000D_
    /* select with custom icons */_x000D_
    .ui-selectmenu-menu .ui-menu.customicons .ui-menu-item-wrapper {_x000D_
      padding: 0.5em 0 0.5em 3em;_x000D_
    }_x000D_
    .ui-selectmenu-menu .ui-menu.customicons .ui-menu-item .ui-icon {_x000D_
      height: 24px;_x000D_
      width: 24px;_x000D_
      top: 0.1em;_x000D_
    }_x000D_
    .ui-icon.video {_x000D_
      background: url("images/24-video-square.png") 0 0 no-repeat;_x000D_
    }_x000D_
    .ui-icon.podcast {_x000D_
      background: url("images/24-podcast-square.png") 0 0 no-repeat;_x000D_
    }_x000D_
    .ui-icon.rss {_x000D_
      background: url("images/24-rss-square.png") 0 0 no-repeat;_x000D_
    }_x000D_
 _x000D_
    /* select with CSS avatar icons */_x000D_
    option.avatar {_x000D_
      background-repeat: no-repeat !important;_x000D_
      padding-left: 20px;_x000D_
    }_x000D_
    .avatar .ui-icon {_x000D_
      background-position: left top;_x000D_
    }
_x000D_
<link href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" rel="stylesheet"/>_x000D_
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>_x000D_
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>_x000D_
<!doctype html>_x000D_
<html lang="en">_x000D_
<head>_x000D_
  <meta charset="utf-8">_x000D_
  <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
  <title>jQuery UI Selectmenu - Custom Rendering</title>_x000D_
  _x000D_
</head>_x000D_
<body>_x000D_
 _x000D_
<div class="demo">_x000D_
 _x000D_
<form action="#">_x000D_
  <h2>Selectmenu with framework icons</h2>_x000D_
  <fieldset>_x000D_
    <label for="filesA">Select a File:</label>_x000D_
    <select name="filesA" id="filesA">_x000D_
      <option value="jquery" data-class="ui-icon-script">jQuery.js</option>_x000D_
      <option value="jquerylogo" data-class="ui-icon-image">jQuery Logo</option>_x000D_
      <option value="jqueryui" data-class="ui-icon-script">ui.jQuery.js</option>_x000D_
      <option value="jqueryuilogo" selected="selected" data-class="ui-icon-image">jQuery UI Logo</option>_x000D_
      <option value="somefile" disabled="disabled" data-class="ui-icon-help">Some unknown file</option>_x000D_
    </select>_x000D_
  </fieldset>_x000D_
 _x000D_
  <h2>Selectmenu with custom icon images</h2>_x000D_
  <fieldset>_x000D_
    <label for="filesB">Select a podcast:</label>_x000D_
    <select name="filesB" id="filesB">_x000D_
      <option value="mypodcast" data-class="podcast">John Resig Podcast</option>_x000D_
      <option value="myvideo" data-class="video">Scott González Video</option>_x000D_
      <option value="myrss" data-class="rss">jQuery RSS XML</option>_x000D_
    </select>_x000D_
  </fieldset>_x000D_
 _x000D_
  <h2>Selectmenu with custom avatar 16x16 images as CSS background</h2>_x000D_
  <fieldset>_x000D_
    <label for="people">Select a Person:</label>_x000D_
    <select name="people" id="people">_x000D_
      <option value="1" data-class="avatar" data-style="background-image: url(&apos;http://www.gravatar.com/avatar/b3e04a46e85ad3e165d66f5d927eb609?d=monsterid&amp;r=g&amp;s=16&apos;);">John Resig</option>_x000D_
      <option value="2" data-class="avatar" data-style="background-image: url(&apos;http://www.gravatar.com/avatar/e42b1e5c7cfd2be0933e696e292a4d5f?d=monsterid&amp;r=g&amp;s=16&apos;);">Tauren Mills</option>_x000D_
      <option value="3" data-class="avatar" data-style="background-image: url(&apos;http://www.gravatar.com/avatar/bdeaec11dd663f26fa58ced0eb7facc8?d=monsterid&amp;r=g&amp;s=16&apos;);">Jane Doe</option>_x000D_
    </select>_x000D_
  </fieldset>_x000D_
</form>_x000D_
 _x000D_
</div>_x000D_
 _x000D_
 _x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Powershell: convert string to number

Simply casting the string as an int won't work reliably. You need to convert it to an int32. For this you can use the .NET convert class and its ToInt32 method. The method requires a string ($strNum) as the main input, and the base number (10) for the number system to convert to. This is because you can not only convert to the decimal system (the 10 base number), but also to, for example, the binary system (base 2).

Give this method a try:

[string]$strNum = "1.500"
[int]$intNum = [convert]::ToInt32($strNum, 10)

$intNum

Force overwrite of local file with what's in origin repo?

If you want to overwrite only one file:

git fetch
git checkout origin/master <filepath>

If you want to overwrite all changed files:

git fetch
git reset --hard origin/master

(This assumes that you're working on master locally and you want the changes on the origin's master - if you're on a branch, substitute that in instead.)

Python, creating objects

class Student(object):
    name = ""
    age = 0
    major = ""

    # The class "constructor" - It's actually an initializer 
    def __init__(self, name, age, major):
        self.name = name
        self.age = age
        self.major = major

def make_student(name, age, major):
    student = Student(name, age, major)
    return student

Note that even though one of the principles in Python's philosophy is "there should be one—and preferably only one—obvious way to do it", there are still multiple ways to do this. You can also use the two following snippets of code to take advantage of Python's dynamic capabilities:

class Student(object):
    name = ""
    age = 0
    major = ""

def make_student(name, age, major):
    student = Student()
    student.name = name
    student.age = age
    student.major = major
    # Note: I didn't need to create a variable in the class definition before doing this.
    student.gpa = float(4.0)
    return student

I prefer the former, but there are instances where the latter can be useful – one being when working with document databases like MongoDB.

How to check Oracle patches are installed?

Here is an article on how to check and or install new patches :


To find the OPatch tool setup your database enviroment variables and then issue this comand:

cd $ORACLE_HOME/OPatch 
> pwd
/oracle/app/product/10.2.0/db_1/OPatch

To list all the patches applies to your database use the lsinventory option:

[oracle@DCG023 8828328]$ opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.4
Copyright (c) 2012, Oracle Corporation. All rights reserved.

Oracle Home : /u00/product/11.2.0/dbhome_1
Central Inventory : /u00/oraInventory
from : /u00/product/11.2.0/dbhome_1/oraInst.loc
OPatch version : 11.2.0.3.4
OUI version : 11.2.0.1.0
Log file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2013-11-13_13-55-22PM_1.log
Lsinventory Output file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/lsinv/lsinventory2013-11-13_13-55-22PM.txt


Installed Top-level Products (1):
Oracle Database 11g 11.2.0.1.0
There are 1 products installed in this Oracle Home.

Interim patches (1) :
Patch 8405205 : applied on Mon Aug 19 15:18:04 BRT 2013
Unique Patch ID: 11805160
Created on 23 Sep 2009, 02:41:32 hrs PST8PDT
Bugs fixed:
8405205

OPatch succeeded.

To list the patches using sql :

select * from registry$history;

Iterator Loop vs index loop

The special thing about iterators is that they provide the glue between algorithms and containers. For generic code, the recommendation would be to use a combination of STL algorithms (e.g. find, sort, remove, copy) etc. that carries out the computation that you have in mind on your data structure (vector, list, map etc.), and to supply that algorithm with iterators into your container.

Your particular example could be written as a combination of the for_each algorithm and the vector container (see option 3) below), but it's only one out of four distinct ways to iterate over a std::vector:

1) index-based iteration

for (std::size_t i = 0; i != v.size(); ++i) {
    // access element as v[i]

    // any code including continue, break, return
}

Advantages: familiar to anyone familiar with C-style code, can loop using different strides (e.g. i += 2).

Disadvantages: only for sequential random access containers (vector, array, deque), doesn't work for list, forward_list or the associative containers. Also the loop control is a little verbose (init, check, increment). People need to be aware of the 0-based indexing in C++.

2) iterator-based iteration

for (auto it = v.begin(); it != v.end(); ++it) {
    // if the current index is needed:
    auto i = std::distance(v.begin(), it); 

    // access element as *it

    // any code including continue, break, return
}

Advantages: more generic, works for all containers (even the new unordered associative containers, can also use different strides (e.g. std::advance(it, 2));

Disadvantages: need extra work to get the index of the current element (could be O(N) for list or forward_list). Again, the loop control is a little verbose (init, check, increment).

3) STL for_each algorithm + lambda

std::for_each(v.begin(), v.end(), [](T const& elem) {
     // if the current index is needed:
     auto i = &elem - &v[0];

     // cannot continue, break or return out of the loop
});

Advantages: same as 2) plus small reduction in loop control (no check and increment), this can greatly reduce your bug rate (wrong init, check or increment, off-by-one errors).

Disadvantages: same as explicit iterator-loop plus restricted possibilities for flow control in the loop (cannot use continue, break or return) and no option for different strides (unless you use an iterator adapter that overloads operator++).

4) range-for loop

for (auto& elem: v) {
     // if the current index is needed:
     auto i = &elem - &v[0];

    // any code including continue, break, return
}

Advantages: very compact loop control, direct access to the current element.

Disadvantages: extra statement to get the index. Cannot use different strides.

What to use?

For your particular example of iterating over std::vector: if you really need the index (e.g. access the previous or next element, printing/logging the index inside the loop etc.) or you need a stride different than 1, then I would go for the explicitly indexed-loop, otherwise I'd go for the range-for loop.

For generic algorithms on generic containers I'd go for the explicit iterator loop unless the code contained no flow control inside the loop and needed stride 1, in which case I'd go for the STL for_each + a lambda.

Threads vs Processes in Linux

If you want to create a pure a process as possible, you would use clone() and set all the clone flags. (Or save yourself the typing effort and call fork())

If you want to create a pure a thread as possible, you would use clone() and clear all the clone flags (Or save yourself the typing effort and call pthread_create())

There are 28 flags that dictate the level of sharing. This means that there are over 268 million flavors of tasks that you can create, depending on what you want to share.

This is what we mean when we say that Linux does not distinguish between a process and a thread, but rather alludes to any flow of control within a program as a task. The rationale for not distinguishing between the two is, well, not uniquely defining over 268 million flavors!

Therefore, making the "perfect decision" of whether to use a process or thread is really about deciding which of the 28 resources to clone

enter image description here

The matching wildcard is strict, but no declaration can be found for element 'context:component-scan

Add This Two Schema locations. That's enough and Efficient instead of adding all the unnecessary schema

 http://www.springframework.org/schema/context
 http://www.springframework.org/schema/context/spring-context.xsd

What does $(function() {} ); do?

I think you may be confusing Javascript with jQuery methods. Vanilla or plain Javascript is something like:

function example() {
}

A function of that nature can be called at any time, anywhere.

jQuery (a library built on Javascript) has built in functions that generally required the DOM to be fully rendered before being called. The syntax for when this is completed is:

$(document).ready(function() {
});

So a jQuery function, which is prefixed with the $ or the word jQuery generally is called from within that method.

$(document).ready(function() {        
    // Assign all list items on the page to be the  color red.  
    //      This does not work until AFTER the entire DOM is "ready", hence the $(document).ready()
    $('li').css('color', 'red');   
});

The pseudo-code for that block is:

When the document object model $(document) is ready .ready(), call the following function function() { }. In that function, check for all <li>'s on the page $('li') and using the jQuery method .CSS() to set the CSS property "color" to the value "red" .css('color', 'red');

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

You will have to annotate your service with @Service since you have said I am using annotations for mapping

regex string replace

Just change + to -:

str = str.replace(/[^a-z0-9-]/g, "");

You can read it as:

  1. [^ ]: match NOT from the set
  2. [^a-z0-9-]: match if not a-z, 0-9 or -
  3. / /g: do global match

More information:

how can the textbox width be reduced?

Is not nice to define textbox width without using CSS, be warned ;-)

<input type="text" name="d" value="4" size="4" />

Maven Modules + Building a Single Specific Module

If you have previously run mvn install on project B it will have been installed to your local repository, so when you build package A Maven can resolve the dependency. So as long as you install project B each time you change it your builds for project A will be up to date.

You can define a multi-module project with an aggregator pom to build a set of projects.

It's also worthwhile mentioning m2eclipse, it integrates Maven into Eclipse and allows you to (optionally) resolve dependencies from the workspace. So if you are hacking away on multiple projects, the workspace content will be used for compilation. Once you are happy with your changes, run mvn install (on each project in turn, or using an aggregator) to put them in your local repository.

Inserting a tab character into text using C#

In addition to the anwsers above you can use PadLeft or PadRight:

string name = "John";
string surname = "Smith";

Console.WriteLine("Name:".PadRight(15)+"Surname:".PadRight(15));
Console.WriteLine( name.PadRight(15) + surname.PadRight(15));

This will fill in the string with spaces to the left or right.

Label word wrapping

Refer to Automatically Wrap Text in Label. It describes how to create your own growing label.

Here is the full source taken from the above reference:

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

public class GrowLabel : Label {
  private bool mGrowing;
  public GrowLabel() {
    this.AutoSize = false;
  }
  private void resizeLabel() {
    if (mGrowing) return;
    try {
      mGrowing = true;
      Size sz = new Size(this.Width, Int32.MaxValue);
      sz = TextRenderer.MeasureText(this.Text, this.Font, sz, TextFormatFlags.WordBreak);
      this.Height = sz.Height;
    }
    finally {
      mGrowing = false;
    }
  }
  protected override void OnTextChanged(EventArgs e) {
    base.OnTextChanged(e);
    resizeLabel();
  }
  protected override void OnFontChanged(EventArgs e) {
    base.OnFontChanged(e);
    resizeLabel();
  }
  protected override void OnSizeChanged(EventArgs e) {
    base.OnSizeChanged(e);
    resizeLabel();
  }
}

unable to install pg gem

On Mac brew install postgres THEN bundle install

Secure hash and salt for PHP passwords

I'm using Phpass which is a simple one-file PHP class that could be implemented very easily in nearly every PHP project. See also The H.

By default it used strongest available encryption that is implemented in Phpass, which is bcrypt and falls back to other encryptions down to MD5 to provide backward compatibility to frameworks like Wordpress.

The returned hash could be stored in database as it is. Sample use for generating hash is:

$t_hasher = new PasswordHash(8, FALSE);
$hash = $t_hasher->HashPassword($password);

To verify password, one can use:

$t_hasher = new PasswordHash(8, FALSE);
$check = $t_hasher->CheckPassword($password, $hash);

How do I get a substring of a string in Python?

One example seems to be missing here: full (shallow) copy.

>>> x = "Hello World!"
>>> x
'Hello World!'
>>> x[:]
'Hello World!'
>>> x==x[:]
True
>>>

This is a common idiom for creating a copy of sequence types (not of interned strings), [:]. Shallow copies a list, see Python list slice syntax used for no obvious reason.

Python: TypeError: object of type 'NoneType' has no len()

shuffle(names) is an in-place operation. Drop the assignment.

This function returns None and that's why you have the error:

TypeError: object of type 'NoneType' has no len()

How to convert int[] to Integer[] in Java?

Native Java 8 (one line)

With Java 8, int[] can be converted to Integer[] easily:

int[] data = {1,2,3,4,5,6,7,8,9,10};

// To boxed array
Integer[] what = Arrays.stream( data ).boxed().toArray( Integer[]::new );
Integer[] ever = IntStream.of( data ).boxed().toArray( Integer[]::new );

// To boxed list
List<Integer> you  = Arrays.stream( data ).boxed().collect( Collectors.toList() );
List<Integer> like = IntStream.of( data ).boxed().collect( Collectors.toList() );

As others stated, Integer[] is usually not a good map key. But as far as conversion goes, we now have a relatively clean and native code.

how to select rows based on distinct values of A COLUMN only

Try this - you need a CTE (Common Table Expression) that partitions (groups) your data by distinct e-mail address, and sorts each group by ID - smallest first. Then you just select the first entry for each group - that should give you what you're looking for:

;WITH DistinctMails AS
(
    SELECT ID, MailID, EMailAddress, NAME,
        ROW_NUMBER() OVER(PARTITION BY EMailAddress ORDER BY ID) AS 'RowNum'
    FROM dbo.YourMailTable
)
SELECT *
FROM DistinctMails
WHERE RowNum = 1

This works on SQL Server 2005 and newer (you didn't mention what version you're using...)

Can't bind to 'ngForOf' since it isn't a known property of 'tr' (final release)

I received the error because the component I was using wasn't registered in the declarations: [] section of the module.

After adding the component the error went away. I would have hoped for something less obscure than this error message to indicate the real problem.

angular2 submit form by pressing enter without submit button

I prefer (keydown.enter)="mySubmit()" because there won't be added a line break if the cursor was somewhere within a <textarea> but not at its end.

SQL - using alias in Group By

SQL Server doesn't allow you to reference the alias in the GROUP BY clause because of the logical order of processing. The GROUP BY clause is processed before the SELECT clause, so the alias is not known when the GROUP BY clause is evaluated. This also explains why you can use the alias in the ORDER BY clause.

Here is one source for information on the SQL Server logical processing phases.

What are MVP and MVC and what is the difference?

enter image description here

MVC (Model View Controller)

The input is directed at the Controller first, not the view. That input might be coming from a user interacting with a page, but it could also be from simply entering a specific url into a browser. In either case, its a Controller that is interfaced with to kick off some functionality. There is a many-to-one relationship between the Controller and the View. That’s because a single controller may select different views to be rendered based on the operation being executed. Note the one way arrow from Controller to View. This is because the View doesn’t have any knowledge of or reference to the controller. The Controller does pass back the Model, so there is knowledge between the View and the expected Model being passed into it, but not the Controller serving it up.

MVP (Model View Presenter)

The input begins with the View, not the Presenter. There is a one-to-one mapping between the View and the associated Presenter. The View holds a reference to the Presenter. The Presenter is also reacting to events being triggered from the View, so its aware of the View its associated with. The Presenter updates the View based on the requested actions it performs on the Model, but the View is not Model aware.

For more Reference

Instagram how to get my user id from username?

I think the best, simplest and securest method is to open your instagram profile in a browser, view source code and look for user variable (ctrl+f "user":{") inside main javascript code. The id number inside user variable should be your id.

This is the code how it looked in the moment of writing this answer (it can, and probably will be changed in future):

"user":{"username":"...","profile_picture":"...","id":"..........","full_name":"..."}},

AngularJS : Why ng-bind is better than {{}} in angular?

Visibility:

While your angularjs is bootstrapping, the user might see your placed brackets in the html. This can be handled with ng-cloak. But for me this is a workaround, that I don't need to use, if I use ng-bind.


Performance:

The {{}} is much slower.

This ng-bind is a directive and will place a watcher on the passed variable. So the ng-bind will only apply, when the passed value does actually change.

The brackets on the other hand will be dirty checked and refreshed in every $digest, even if it's not necessary.


I am currently building a big single page app (~500 bindings per view). Changing from {{}} to strict ng-bind did save us about 20% in every scope.$digest.


Suggestion:

If you use a translation module such as angular-translate, always prefer directives before brackets annotation.

{{'WELCOME'|translate}} => <span ng-translate="WELCOME"></span>

If you need a filter function, better go for a directive, that actually just uses your custom filter. Documentation for $filter service


UPDATE 28.11.2014 (but maybe off the topic):

In Angular 1.3x the bindonce functionality was introduced. Therefore you can bind the value of an expression/attribute once (will be bound when != 'undefined').

This is useful when you don't expect your binding to change.

Usage: Place :: before your binding:

<ul>  
  <li ng-repeat="item in ::items">{{item}}</li>
</ul>  
<a-directive name="::item">
<span data-ng-bind="::value"></span>

Example:

ng-repeat to output some data in the table, with multiple bindings per row. Translation-bindings, filter outputs, which get executed in every scope digest.

Is there a simple way to delete a list element by value?

Usually Python will throw an Exception if you tell it to do something it can't so you'll have to do either:

if c in a:
    a.remove(c)

or:

try:
    a.remove(c)
except ValueError:
    pass

An Exception isn't necessarily a bad thing as long as it's one you're expecting and handle properly.

SQL How to remove duplicates within select query?

You have to convert the "DateTime" to a "Date". Then you can easier select just one for the given date no matter the time for that date.

"The Controls collection cannot be modified because the control contains code blocks"

I had this problem, but not via the Header. My placeholder was in the body. So I replaced all the <%= with <%# and did

protected void Page_Load(object sender, EventArgs e)
{
    Page.Header.DataBind();    
}

and it worked.

How to see the CREATE VIEW code for a view in PostgreSQL?

If you want an ANSI SQL-92 version:

select view_definition from information_schema.views where table_name = 'view_name';

How can I echo HTML in PHP?

$enter_string = '<textarea style="color:#FF0000;" name="message">EXAMPLE</textarea>';

echo('Echo as HTML' . htmlspecialchars((string)$enter_string));

What are alternatives to ExtJS?

Nothing compares to in terms of community size and presence on StackOverflow. Despite previous controversy, Ext JS now has a GPLv3 open source license. Its learning curve is long, but it can be quite rewarding once learned. Ext JS lacks a Material Design theme, and the team has repeatedly refused to release the source code on GitHub. For mobile, one must use the separate Sencha Touch library.

Have in mind also that,

large JavaScript libraries, such as YUI, have been receiving less attention from the community. Many developers today look at large JavaScript libraries as walled gardens they don’t want to be locked into.

-- Announcement of YUI development being ceased

That said, below are a number of Ext JS alternatives currently available.

Leading client widget libraries

  1. Blueprint is a React-based UI toolkit developed by big data analytics company Palantir in TypeScript, and "optimized for building complex data-dense interfaces for desktop applications". Actively developed on GitHub as of May 2019, with comprehensive documentation. Components range from simple (chips, toast, icons) to complex (tree, data table, tag input with autocomplete, date range picker. No accordion or resizer.

    Blueprint targets modern browsers (Chrome, Firefox, Safari, IE 11, and Microsoft Edge) and is licensed under a modified Apache license.

    Sandbox / demoGitHubDocs

  2. Webix - an advanced, easy to learn, mobile-friendly, responsive and rich free&open source JavaScript UI components library. Webix spun off from DHTMLX Touch (a project with 8 years of development behind it - see below) and went on to become a standalone UI components framework. The GPL3 edition allows commercial use and lets non-GPL applications using Webix keep their license, e.g. MIT, via a license exemption for FLOSS. Webix has 55 UI widgets, including trees, grids, treegrids and charts. Funding comes from a commercial edition with some advanced widgets (Pivot, Scheduler, Kanban, org chart etc.). Webix has an extensive list of free and commercial widgets, and integrates with most popular frameworks (React, Vue, Meteor, etc) and UI components.

    Webix

    Skins look modern, and include a Material Design theme. The Touch theme also looks quite Material Design-ish. See also the Skin Builder.

    Minimal GitHub presence, but includes the library code, and the documentation (which still needs major improvements). Webix suffers from a having a small team and a lack of marketing. However, they have been responsive to user feedback, both on GitHub and on their forum.

    The library was lean (128Kb gzip+minified for all 55 widgets as of ~2015), faster than ExtJS, dojo and others, and the design is pleasant-looking. The current version of Webix (v6, as of Nov 2018) got heavier (400 - 676kB minified but NOT gzipped).

    The demos on Webix.com look and function great. The developer, XB Software, uses Webix in solutions they build for paying customers, so there's likely a good, funded future ahead of it.

    Webix aims for backwards compatibility down to IE8, and as a result carries some technical debt.

    WikipediaGitHubPlayground/sandboxAdmin dashboard demoDemosWidget samples

  3. react-md - MIT-licensed Material Design UI components library for React. Responsive, accessible. Implements components from simple (buttons, cards) to complex (sortable tables, autocomplete, tags input, calendars). One lead author, ~1900 GitHub stars.

  4. - jQuery-based UI toolkit with 40+ basic open-source widgets, plus commercial professional widgets (grids, trees, charts etc.). Responsive&mobile support. Works with Bootstrap and AngularJS. Modern, with Material Design themes. The documentation is available on GitHub, which has enabled numerous contributions from users (4500+ commits, 500+ PRs as of Jan 2015).

    enter image description here

    Well-supported commercially, claiming millions of developers, and part of a large family of developer tools. Telerik has received many accolades, is a multi-national company (Bulgaria, US), was acquired by Progress Software, and is a thought leader.

    A Kendo UI Professional developer license costs $700 and posting access to most forums is conditioned upon having a license or being in the trial period.

    [Wikipedia] • GitHub/TelerikDemosPlaygroundTools

  5. OpenUI5 - jQuery-based UI framework with 180 widgets, Apache 2.0-licensed and fully-open sourced and funded by German software giant SAP SE.

    OpenUI5

    The community is much larger than that of Webix, SAP is hiring developers to grow OpenUI5, and they presented OpenUI5 at OSCON 2014.

    The desktop themes are rather lackluster, but the Fiori design for web and mobile looks clean and neat.

    WikipediaGitHubMobile-first controls demosDesktop controls demosSO

  6. DHTMLX - JavaScript library for building rich Web and Mobile apps. Looks most like ExtJS - check the demos. Has been developed since 2005 but still looks modern. All components except TreeGrid are available under GPLv2 but advanced features for many components are only available in the commercial PRO edition - see for example the tree. Claims to be used by many Fortune 500 companies.

    DHTMLX

    Minimal presence on GitHub (the main library code is missing) and StackOverflow but active forum. The documentation is not available on GitHub, which makes it difficult to improve by the community.

  7. Polymer, a Web Components polyfill, plus Polymer Paper, Google's implementation of the Material design. Aimed at web and mobile apps. Doesn't have advanced widgets like trees or even grids but the controls it provides are mobile-first and responsive. Used by many big players, e.g. IBM or USA Today.

    Polymer Paper Elements

  8. Ant Design claims it is "a design language for background applications", influenced by "nature" and helping designers "create low-entropy atmosphere for developer team". That's probably a poor translation from Chinese for "UI components for enterprise web applications". It's a React UI library written in TypeScript, with many components, from simple (buttons, cards) to advanced (autocomplete, calendar, tag input, table).

    The project was born in China, is popular with Chinese companies, and parts of the documentation are available only in Chinese. Quite popular on GitHub, yet it makes the mistake of splitting the community into Chinese and English chat rooms. The design looks Material-ish, but fonts are small and the information looks lost in a see of whitespace.

  9. PrimeUI - collection of 45+ rich widgets based on jQuery UI. Apache 2.0 license. Small GitHub community. 35 premium themes available.

  10. qooxdoo - "a universal JavaScript framework with a coherent set of individual components", developed and funded by German hosting provider 1&1 (see the contributors, one of the world's largest hosting companies. GPL/EPL (a business-friendly license).

    Mobile themes look modern but desktop themes look old (gradients).

    Qooxdoo

    WikipediaGitHubWeb/Mobile/Desktop demosWidgets Demo browserWidget browserSOPlaygroundCommunity

  11. jQuery UI - easy to pick up; looks a bit dated; lacks advanced widgets. Of course, you can combine it with independent widgets for particular needs, e.g. trees or other UI components, but the same can be said for any other framework.

  12. + Angular UI. While Angular is backed by Google, it's being radically revamped in the upcoming 2.0 version, and "users will need to get to grips with a new kind of architecture. It's also been confirmed that there will be no migration path from Angular 1.X to 2.0". Moreover, the consensus seems to be that Angular 2 won't really be ready for use until a year or two from now. Angular UI has relatively few widgets (no trees, for example).

  13. DojoToolkit and their powerful Dijit set of widgets. Completely open-sourced and actively developed on GitHub, but development is now (Nov 2018) focused on the new dojo.io framework, which has very few basic widgets. BSD/AFL license. Development started in 2004 and the Dojo Foundation is being sponsored by IBM, Google, and others - see Wikipedia. 7500 questions here on SO.

    Dojo Dijit

    Themes look desktop-oriented and dated - see the theme tester in dijit. The official theme previewer is broken and only shows "Claro". A Bootstrap theme exists, which looks a lot like Bootstrap, but doesn't use Bootstrap classes. In Jan 2015, I started a thread on building a Material Design theme for Dojo, which got quite popular within the first hours. However, there are questions regarding building that theme for the current Dojo 1.10 vs. the next Dojo 2.0. The response to that thread shows an active and wide community, covering many time zones.

    Unfortunately, Dojo has fallen out of popularity and fewer companies appear to use it, despite having (had?) a strong foothold in the enterprise world. In 2009-2012, its learning curve was steep and the documentation needed improvements; while the documentation has substantially improved, it's unclear how easy it is to pick up Dojo nowadays.

    With a Material Design theme, Dojo (2.0?) might be the killer UI components framework.

    WikipediaGitHubThemesDemosDesktop widgetsSO

  14. Enyo - front-end library aimed at mobile and TV apps (e.g. large touch-friendly controls). Developed by LG Electronix and Apache-licensed on GitHub.

  15. The radical Cappuccino - Objective-J (a superset of JavaScript) instead of HTML+CSS+DOM

  16. Mochaui, MooTools UI Library User Interface Library. <300 GitHub stars.

  17. CrossUI - cross-browser JS framework to develop and package the exactly same code and UI into Web Apps, Native Desktop Apps (Windows, OS X, Linux) and Mobile Apps (iOS, Android, Windows Phone, BlackBerry). Open sourced LGPL3. Featured RAD tool (form builder etc.). The UI looks desktop-, not web-oriented. Actively developed, small community. No presence on GitHub.

  18. ZinoUI - simple widgets. The DataTable, for instance, doesn't even support sorting.

  19. Wijmo - good-looking commercial widgets, with old (jQuery UI) widgets open-sourced on GitHub (their development stopped in 2013). Developed by ComponentOne, a division of GrapeCity. See Wijmo Complete vs. Open.

  20. CxJS - commercial JS framework based on React, Babel and webpack offering form elements, form validation, advanced grid control, navigational elements, tooltips, overlays, charts, routing, layout support, themes, culture dependent formatting and more.

CxJS

Widgets - Demo Apps - Examples - GitHub

Full-stack frameworks

  1. SproutCore - developed by Apple for web applications with native performance, handling large data sets on the client. Powers iCloud.com. Not intended for widgets.

  2. Wakanda: aimed at business/enterprise web apps - see What is Wakanda?. Architecture:

  3. Servoy - "a cross platform frontend development and deployment environment for SQL databases". Boasts a "full WYSIWIG (What You See Is What You Get) UI designer for HTML5 with built-in data-binding to back-end services", responsive design, support for HTML6 Web Components, Websockets and mobile platforms. Written in Java and generates JavaScript code using various JavaBeans.

  4. SmartClient/SmartGWT - mobile and cross-browser HTML5 UI components combined with a Java server. Aimed at building powerful business apps - see demos.

  5. Vaadin - full-stack Java/GWT + JavaScript/HTML3 web app framework

  6. Backbase - portal software

  7. Shiny - front-end library on top R, with visualization, layout and control widgets

  8. ZKOSS: Java+jQuery+Bootstrap framework for building enterprise web and mobile apps.

CSS libraries + minimal widgets

These libraries don't implement complex widgets such as tables with sorting/filtering, autocompletes, or trees.

  1. Bootstrap

  2. Foundation for Apps - responsive front-end framework on top of AngularJS; more of a grid/layout/navigation library

  3. UI Kit - similar to Bootstrap, with fewer widgets, but with official off-canvas.

Libraries using HTML Canvas

Using the canvas elements allows for complete control over the UI, and great cross-browser compatibility, but comes at the cost of missing native browser functionality, e.g. page search via Ctrl/Cmd+F.

  1. Zebra - demos

No longer developed as of Dec 2014

  1. Yahoo! User Interface - YUI, launched in 2005, but no longer maintained by the core contributors - see the announcement, which highlights reasons why large UI widget libraries are perceived as walled gardens that developers don't want to be locked into.
  2. echo3, GitHub. Supports writing either server-side Java applications that don't require developer knowledge of HTML, HTTP, or JavaScript, or client-side JavaScript-based applications do not require a server, but can communicate with one via AJAX. Last update: July 2013.
  3. ampleSDK
  4. Simpler widgets livepipe.net
  5. JxLib
  6. rialto
  7. Simple UI kit
  8. Prototype-ui

Other lists

printf \t option

A tab is a tab. How many spaces it consumes is a display issue, and depends on the settings of your shell.

If you want to control the width of your data, then you could use the width sub-specifiers in the printf format string. Eg. :

printf("%5d", 2);

It's not a complete solution (if the value is longer than 5 characters, it will not be truncated), but might be ok for your needs.

If you want complete control, you'll probably have to implement it yourself.

How to ORDER BY a SUM() in MySQL?

Without a GROUP BY clause, any summation will roll all rows up into a single row, so your query will indeed not work. If you grouped by, say, name, and ordered by sum(c_counts+f_counts), then you might get some useful results. But you would have to group by something.

Group by & count function in sqlalchemy

If you are using Table.query property:

from sqlalchemy import func
Table.query.with_entities(Table.column, func.count(Table.column)).group_by(Table.column).all()

If you are using session.query() method (as stated in miniwark's answer):

from sqlalchemy import func
session.query(Table.column, func.count(Table.column)).group_by(Table.column).all()

Testing if value is a function

Make sure you are calling typeof on the actual function, not a string literal:

function x() { 
    console.log("hi"); 
}

typeof "x"; // returns "string"

typeof x; // returns "function"

PostgreSQL INSERT ON CONFLICT UPDATE (upsert) use all excluded values

Postgres hasn't implemented an equivalent to INSERT OR REPLACE. From the ON CONFLICT docs (emphasis mine):

It can be either DO NOTHING, or a DO UPDATE clause specifying the exact details of the UPDATE action to be performed in case of a conflict.

Though it doesn't give you shorthand for replacement, ON CONFLICT DO UPDATE applies more generally, since it lets you set new values based on preexisting data. For example:

INSERT INTO users (id, level)
VALUES (1, 0)
ON CONFLICT (id) DO UPDATE
SET level = users.level + 1;

How to Free Inode Usage?

We faced similar issue recently, In case if a process refers to a deleted file, the Inode shall not be released, so you need to check lsof /, and kill/ restart the process will release the inodes.

Correct me if am wrong here.

@ variables in Ruby on Rails

title is a local variable. They only exists within its scope (current block)

@title is an instance variable - and is available to all methods within the class.

You can read more here: http://strugglingwithruby.blogspot.dk/2010/03/variables.html

In Ruby on Rails - declaring your variables in your controller as instance variables (@title) makes them available to your view.

How to return string value from the stored procedure

change your

return @str1+'present in the string' ;

to

set @r = @str1+'present in the string' 

Set default value of javascript object attributes

I saw an article yesterday that mentions an Object.__noSuchMethod__ property: JavascriptTips I've not had a chance to play around with it, so I don't know about browser support, but maybe you could use that in some way?

How to dispatch a Redux action with a timeout?

Using Redux-saga

As Dan Abramov said, if you want more advanced control over your async code, you might take a look at redux-saga.

This answer is a simple example, if you want better explanations on why redux-saga can be useful for your application, check this other answer.

The general idea is that Redux-saga offers an ES6 generators interpreter that permits you to easily write async code that looks like synchronous code (this is why you'll often find infinite while loops in Redux-saga). Somehow, Redux-saga is building its own language directly inside Javascript. Redux-saga can feel a bit difficult to learn at first, because you need basic understanding of generators, but also understand the language offered by Redux-saga.

I'll try here to describe here the notification system I built on top of redux-saga. This example currently runs in production.

Advanced notification system specification

  • You can request a notification to be displayed
  • You can request a notification to hide
  • A notification should not be displayed more than 4 seconds
  • Multiple notifications can be displayed at the same time
  • No more than 3 notifications can be displayed at the same time
  • If a notification is requested while there are already 3 displayed notifications, then queue/postpone it.

Result

Screenshot of my production app Stample.co

toasts

Code

Here I named the notification a toast but this is a naming detail.

function* toastSaga() {

    // Some config constants
    const MaxToasts = 3;
    const ToastDisplayTime = 4000;


    // Local generator state: you can put this state in Redux store
    // if it's really important to you, in my case it's not really
    let pendingToasts = []; // A queue of toasts waiting to be displayed
    let activeToasts = []; // Toasts currently displayed


    // Trigger the display of a toast for 4 seconds
    function* displayToast(toast) {
        if ( activeToasts.length >= MaxToasts ) {
            throw new Error("can't display more than " + MaxToasts + " at the same time");
        }
        activeToasts = [...activeToasts,toast]; // Add to active toasts
        yield put(events.toastDisplayed(toast)); // Display the toast (put means dispatch)
        yield call(delay,ToastDisplayTime); // Wait 4 seconds
        yield put(events.toastHidden(toast)); // Hide the toast
        activeToasts = _.without(activeToasts,toast); // Remove from active toasts
    }

    // Everytime we receive a toast display request, we put that request in the queue
    function* toastRequestsWatcher() {
        while ( true ) {
            // Take means the saga will block until TOAST_DISPLAY_REQUESTED action is dispatched
            const event = yield take(Names.TOAST_DISPLAY_REQUESTED);
            const newToast = event.data.toastData;
            pendingToasts = [...pendingToasts,newToast];
        }
    }


    // We try to read the queued toasts periodically and display a toast if it's a good time to do so...
    function* toastScheduler() {
        while ( true ) {
            const canDisplayToast = activeToasts.length < MaxToasts && pendingToasts.length > 0;
            if ( canDisplayToast ) {
                // We display the first pending toast of the queue
                const [firstToast,...remainingToasts] = pendingToasts;
                pendingToasts = remainingToasts;
                // Fork means we are creating a subprocess that will handle the display of a single toast
                yield fork(displayToast,firstToast);
                // Add little delay so that 2 concurrent toast requests aren't display at the same time
                yield call(delay,300);
            }
            else {
                yield call(delay,50);
            }
        }
    }

    // This toast saga is a composition of 2 smaller "sub-sagas" (we could also have used fork/spawn effects here, the difference is quite subtile: it depends if you want toastSaga to block)
    yield [
        call(toastRequestsWatcher),
        call(toastScheduler)
    ]
}

And the reducer:

const reducer = (state = [],event) => {
    switch (event.name) {
        case Names.TOAST_DISPLAYED:
            return [...state,event.data.toastData];
        case Names.TOAST_HIDDEN:
            return _.without(state,event.data.toastData);
        default:
            return state;
    }
};

Usage

You can simply dispatch TOAST_DISPLAY_REQUESTED events. If you dispatch 4 requests, only 3 notifications will be displayed, and the 4th one will appear a bit later once the 1st notification disappears.

Note that I don't specifically recommend dispatching TOAST_DISPLAY_REQUESTED from JSX. You'd rather add another saga that listens to your already-existing app events, and then dispatch the TOAST_DISPLAY_REQUESTED: your component that triggers the notification, does not have to be tightly coupled to the notification system.

Conclusion

My code is not perfect but runs in production with 0 bugs for months. Redux-saga and generators are a bit hard initially but once you understand them this kind of system is pretty easy to build.

It's even quite easy to implement more complex rules, like:

  • when too many notifications are "queued", give less display-time for each notification so that the queue size can decrease faster.
  • detect window size changes, and change the maximum number of displayed notifications accordingly (for example, desktop=3, phone portrait = 2, phone landscape = 1)

Honnestly, good luck implementing this kind of stuff properly with thunks.

Note you can do exactly the same kind of thing with redux-observable which is very similar to redux-saga. It's almost the same and is a matter of taste between generators and RxJS.

Uploading Files in ASP.net without using the FileUpload server control

In your aspx :

<form id="form1" runat="server" enctype="multipart/form-data">
 <input type="file" id="myFile" name="myFile" />
 <asp:Button runat="server" ID="btnUpload" OnClick="btnUploadClick" Text="Upload" />
</form>

In code behind :

protected void btnUploadClick(object sender, EventArgs e)
{
    HttpPostedFile file = Request.Files["myFile"];

    //check file was submitted
    if (file != null && file.ContentLength > 0)
    {
        string fname = Path.GetFileName(file.FileName);
        file.SaveAs(Server.MapPath(Path.Combine("~/App_Data/", fname)));
    }
}

Difference between Eclipse Europa, Helios, Galileo

The Eclipse releases are named after the moons of Jupiter, and each denotes a successive release.

Helios is the current release you can download eclipse as your programming needs http://www.eclipse.org/downloads/

How to find the files that are created in the last hour in unix

find ./ -cTime -1 -type f

OR

find ./ -cmin -60 -type f

Dialog with transparent background in Android

Make sure R.layout.themechanger has no background color because by default the dialog has a default background color.

You also need to add dialog.getWindow().setBackgroundDrawable(newColorDrawable(Color.TRANSPARENT));

And finally

<style name="TransparentDialog">
    <item name="android:windowIsFloating">true</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowTitleStyle">@null</item>
</style>

Getting net::ERR_UNKNOWN_URL_SCHEME while calling telephone number from HTML page in Android

Try this way,hope this will help you to solve your problem.

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">

    <WebView
        android:id="@+id/webView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

MyActivity.java

public class MyActivity extends Activity {

    private WebView webView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        webView = (WebView) findViewById(R.id.webView);
        webView.loadData("<a href=\"tel:+1800229933\">Call us free!</a>", "text/html", "utf-8");
    }

}

Please add this permission in AndroidManifest.xml

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

Space between two divs

You can try something like the following:

h1{
   margin-bottom:<x>px;
}
div{
   margin-bottom:<y>px;
}
div:last-of-type{
   margin-bottom:0;
}

or instead of the first h1 rule:

div:first-of-type{
   margin-top:<x>px;
}

or even better use the adjacent sibling selector. With the following selector, you could cover your case in one rule:

div + div{
   margin-bottom:<y>px;
}

Respectively, h1 + div would control the first div after your header, giving you additional styling options.

How to loop backwards in python?

All of these three solutions give the same results if the input is a string:

1.

def reverse(text):
    result = ""
    for i in range(len(text),0,-1):
        result += text[i-1]
    return (result)

2.

text[::-1]

3.

"".join(reversed(text))

Remove Top Line of Text File with PowerShell

While I really admire the answer from @hoge both for a very concise technique and a wrapper function to generalize it and I encourage upvotes for it, I am compelled to comment on the other two answers that use temp files (it gnaws at me like fingernails on a chalkboard!).

Assuming the file is not huge, you can force the pipeline to operate in discrete sections--thereby obviating the need for a temp file--with judicious use of parentheses:

(Get-Content $file | Select-Object -Skip 1) | Set-Content $file

... or in short form:

(gc $file | select -Skip 1) | sc $file

How does origin/HEAD get set?

What moves origin/HEAD "organically"?

  • git clone sets it once to the spot where HEAD is on origin
    • it serves as the default branch to checkout after cloning with git clone

What does HEAD on origin represent?

  • on bare repositories (often repositories “on servers”) it serves as a marker for the default branch, because git clone uses it in such a way
  • on non-bare repositories (local or remote), it reflects the repository’s current checkout

What sets origin/HEAD?

  • git clone fetches and sets it
  • it would make sense if git fetch updates it like any other reference, but it doesn’t
  • git remote set-head origin -a fetches and sets it
    • useful to update the local knowledge of what remote considers the “default branch”

Trivia

  • origin/HEAD can also be set to any other value without contacting the remote: git remote set-head origin <branch>
    • I see no use-case for this, except for testing
  • unfortunately nothing is able to set HEAD on the remote
  • older versions of git did not know which branch HEAD points to on the remote, only which commit hash it finally has: so it just hopefully picked a branch name pointing to the same hash

forEach() in React JSX does not output any HTML

You need to pass an array of element to jsx. The problem is that forEach does not return anything (i.e it returns undefined). So it's better to use map because map returns an array:

class QuestionSet extends Component {
render(){ 
    <div className="container">
       <h1>{this.props.question.text}</h1>
       {this.props.question.answers.map((answer, i) => {     
           console.log("Entered");                 
           // Return the element. Also pass key     
           return (<Answer key={answer} answer={answer} />) 
        })}
}

export default QuestionSet;

How to get First and Last record from a sql query?

I think this code gets the same and is easier to read.

SELECT <some columns> 
FROM mytable
<maybe some joins here>
WHERE date >= (SELECT date from mytable)
OR date <= (SELECT date from mytable);

MySQL root access from all hosts

if you have many networks attached to you OS, yo must especify one of this network in the bind-addres from my.conf file. an example:

[mysqld]
bind-address = 127.100.10.234

this ip is from a ethX configuration.

How to convert Integer to int?

As already written elsewhere:

  • For Java 1.5 and later you don't need to do (almost) anything, it's done by the compiler.
  • For Java 1.4 and before, use Integer.intValue() to convert from Integer to int.

BUT as you wrote, an Integer can be null, so it's wise to check that before trying to convert to int (or risk getting a NullPointerException).

pstmt.setInt(1, (tempID != null ? tempID : 0));  // Java 1.5 or later

or

pstmt.setInt(1, (tempID != null ? tempID.intValue() : 0));  // any version, no autoboxing  

* using a default of zero, could also do nothing, show a warning or ...

I mostly prefer not using autoboxing (second sample line) so it's clear what I want to do.

What should my Objective-C singleton look like?

Edit: This implementation obsoleted with ARC. Please have a look at How do I implement an Objective-C singleton that is compatible with ARC? for correct implementation.

All the implementations of initialize I've read in other answers share a common error.

+ (void) initialize {
  _instance = [[MySingletonClass alloc] init] // <----- Wrong!
}

+ (void) initialize {
  if (self == [MySingletonClass class]){ // <----- Correct!
      _instance = [[MySingletonClass alloc] init] 
  }
}

The Apple documentation recommend you check the class type in your initialize block. Because subclasses call the initialize by default. There exists a non-obvious case where subclasses may be created indirectly through KVO. For if you add the following line in another class:

[[MySingletonClass getInstance] addObserver:self forKeyPath:@"foo" options:0 context:nil]

Objective-C will implicitly create a subclass of MySingletonClass resulting in a second triggering of +initialize.

You may think that you should implicitly check for duplicate initialization in your init block as such:

- (id) init { <----- Wrong!
   if (_instance != nil) {
      // Some hack
   }
   else {
      // Do stuff
   }
  return self;
}

But you will shoot yourself in the foot; or worse give another developer the opportunity to shoot themselves in the foot.

- (id) init { <----- Correct!
   NSAssert(_instance == nil, @"Duplication initialization of singleton");
   self = [super init];
   if (self){
      // Do stuff
   }
   return self;
}

TL;DR, here's my implementation

@implementation MySingletonClass
static MySingletonClass * _instance;
+ (void) initialize {
   if (self == [MySingletonClass class]){
      _instance = [[MySingletonClass alloc] init];
   }
}

- (id) init {
   ZAssert (_instance == nil, @"Duplication initialization of singleton");
   self = [super init];
   if (self) {
      // Initialization
   }
   return self;
}

+ (id) getInstance {
   return _instance;
}
@end

(Replace ZAssert with our own assertion macro; or just NSAssert.)

apache server reached MaxClients setting, consider raising the MaxClients setting

Here's an approach that could resolve your problem, and if not would help with troubleshooting.

  1. Create a second Apache virtual server identical to the current one

  2. Send all "normal" user traffic to the original virtual server

  3. Send special or long-running traffic to the new virtual server

Special or long-running traffic could be report-generation, maintenance ops or anything else you don't expect to complete in <<1 second. This can happen serving APIs, not just web pages.

If your resource utilization is low but you still exceed MaxClients, the most likely answer is you have new connections arriving faster than they can be serviced. Putting any slow operations on a second virtual server will help prove if this is the case. Use the Apache access logs to quantify the effect.

No 'Access-Control-Allow-Origin' header is present on the requested resource- AngularJS

The Chrome Webstore has an extension that adds the 'Access-Control-Allow-Origin' header for you when there is an asynchronous call in the page that tries to access a different host than yours.

The name of the extension is: "Allow-Control-Allow-Origin: *" and this is the link: https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi

What are WSDL, SOAP and REST?

You're not going to "simply" understand something complex.

WSDL is an XML-based language for describing a web service. It describes the messages, operations, and network transport information used by the service. These web services usually use SOAP, but may use other protocols.

A WSDL is readable by a program, and so may be used to generate all, or part of the client code necessary to call the web service. This is what it means to call SOAP-based web services "self-describing".

REST is not related to WSDL at all.

Printing a java map Map<String, Object> - How?

There is a get method in HashMap:

for (String keys : objectSet.keySet())  
{
   System.out.println(keys + ":"+ objectSet.get(keys));
}

libpthread.so.0: error adding symbols: DSO missing from command line

What I have found is that sometimes the library that the linker complains about is not the one causing the problem. Possibly there is a clever way to work out where the problem is but this is what I do:

  • Comment out all the linked libraries in the link command.
  • Clean out all .o's, .so's etc (Usually make clean is enough, but you may want to run a recursive find + rm, or something similar).
  • Uncomment the libraries in the link command one at a time and re-arrange the order as necessary.

@peter karasev: I have come across the same problem with a gcc 4.8.2 cmake project on CentOS7. The order of the libraries in "target_link_libraries" section is important. I guess cmake just passes the list on to the linker as-is, i.e. it doesn't try and work out the correct order. This is reasonable - when you think about it cmake can't know what the correct order is until the linking is successfully completed.

Correct way of looping through C++ arrays

you need to understand difference between std::array::size and sizeof() operator. if you want loop to array elements in conventional way then you could use std::array::size. this will return number of elements in array but if you keen to use C++11 then prefer below code

for(const string &text : texts)
    cout << "value of text: " << text << endl;

How to get the current directory in a C program?

Look up the man page for getcwd.

Detect when browser receives file download

Based on Elmer's example I've prepared my own solution. After elements click with defined download class it lets to show custom message on the screen. I've used focus trigger to hide the message.

JavaScript

$(function(){$('.download').click(function() { ShowDownloadMessage(); }); })

function ShowDownloadMessage()
{
     $('#message-text').text('your report is creating, please wait...');
     $('#message').show();
     window.addEventListener('focus', HideDownloadMessage, false);
}

function HideDownloadMessage(){
    window.removeEventListener('focus', HideDownloadMessage, false);                   
    $('#message').hide();
}

HTML

<div id="message" style="display: none">
    <div id="message-screen-mask" class="ui-widget-overlay ui-front"></div>
    <div id="message-text" class="ui-dialog ui-widget ui-widget-content ui-corner-all ui-front ui-draggable ui-resizable waitmessage">please wait...</div>
</div>

Now you should implement any element to download:

<a class="download" href="file://www.ocelot.com.pl/prepare-report">Download report</a>

or

<input class="download" type="submit" value="Download" name="actionType">

After each download click you will see message your report is creating, please wait...

How to construct a set out of list items in python?

One general way to construct set in iterative way like this:

aset = {e for e in alist}

Adding machineKey to web.config on web-farm sites

This should answer:

How To: Configure MachineKey in ASP.NET 2.0 - Web Farm Deployment Considerations

Web Farm Deployment Considerations

If you deploy your application in a Web farm, you must ensure that the configuration files on each server share the same value for validationKey and decryptionKey, which are used for hashing and decryption respectively. This is required because you cannot guarantee which server will handle successive requests.

With manually generated key values, the settings should be similar to the following example.

<machineKey  
validationKey="21F090935F6E49C2C797F69BBAAD8402ABD2EE0B667A8B44EA7DD4374267A75D7
               AD972A119482D15A4127461DB1DC347C1A63AE5F1CCFAACFF1B72A7F0A281B"       

decryptionKey="ABAA84D7EC4BB56D75D217CECFFB9628809BDB8BF91CFCD64568A145BE59719F"
validation="SHA1"
decryption="AES"
/>

If you want to isolate your application from other applications on the same server, place the in the Web.config file for each application on each server in the farm. Ensure that you use separate key values for each application, but duplicate each application's keys across all servers in the farm.

In short, to set up the machine key refer the following link: Setting Up a Machine Key - Orchard Documentation.

Setting Up the Machine Key Using IIS Manager

If you have access to the IIS management console for the server where Orchard is installed, it is the easiest way to set-up a machine key.

Start the management console and then select the web site. Open the machine key configuration: The IIS web site configuration panel

The machine key control panel has the following settings:

The machine key configuration panel

Uncheck "Automatically generate at runtime" for both the validation key and the decryption key.

Click "Generate Keys" under "Actions" on the right side of the panel.

Click "Apply".

and add the following line to the web.config file in all the webservers under system.web tag if it does not exist.

<machineKey  
    validationKey="21F0SAMPLEKEY9C2C797F69BBAAD8402ABD2EE0B667A8B44EA7DD4374267A75D7
                   AD972A119482D15A4127461DB1DC347C1A63AE5F1CCFAACFF1B72A7F0A281B"           
    decryptionKey="ABAASAMPLEKEY56D75D217CECFFB9628809BDB8BF91CFCD64568A145BE59719F"
    validation="SHA1"
    decryption="AES"
/>

Please make sure that you have a permanent backup of the machine keys and web.config file

How do I access my webcam in Python?

John Montgomery's, answer is great, but at least on Windows, it is missing the line

vc.release()

before

cv2.destroyWindow("preview")

Without it, the camera resource is locked, and can not be captured again before the python console is killed.

Reading a simple text file

Place your text file in the /assets directory under the Android project. Use AssetManager class to access it.

AssetManager am = context.getAssets();
InputStream is = am.open("test.txt");

Or you can also put the file in the /res/raw directory, where the file will be indexed and is accessible by an id in the R file:

InputStream is = context.getResources().openRawResource(R.raw.test);

How do I define the name of image built with docker-compose

after you build your image do the following:

docker tag <image id> mynewtag:version

after that you will see your image is no longer named <none> when you go docker images.

"starting Tomcat server 7 at localhost has encountered a prob"

Open the terminal in ubuntu (ctrl+shift+t)
sudo gedit /etc/tomcat7/server.xml

change the default port in the server.xml,from 8080 to anything like 8081,8181,8008. Then save the file .

Now the project will work nicely without any interruption.

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

How to add an element to Array and shift indexes?

If you prefer to use Apache Commons instead of reinventing the wheel, the current approach is this:

a = ArrayUtils.insert(4, a, 87);

It used to be ArrayUtils.add(...) but that was deprecated a while ago. More info here: 1

Android, canvas: How do I clear (delete contents of) a canvas (= bitmaps), living in a surfaceView?

I tried the answer of @mobistry:

canvas.drawColor(Color.TRANSPARENT, Mode.CLEAR);

But it doesn't worked for me.

The solution, for me, was:

canvas.drawColor(Color.TRANSPARENT, Mode.MULTIPLY);

Maybe some one has the same problem.

What are Long-Polling, Websockets, Server-Sent Events (SSE) and Comet?

In the examples below the client is the browser and the server is the webserver hosting the website.

Before you can understand these technologies, you have to understand classic HTTP web traffic first.

Regular HTTP:

  1. A client requests a webpage from a server.
  2. The server calculates the response
  3. The server sends the response to the client.

HTTP

Ajax Polling:

  1. A client requests a webpage from a server using regular HTTP (see HTTP above).
  2. The client receives the requested webpage and executes the JavaScript on the page which requests a file from the server at regular intervals (e.g. 0.5 seconds).
  3. The server calculates each response and sends it back, just like normal HTTP traffic.

Ajax Polling

Ajax Long-Polling:

  1. A client requests a webpage from a server using regular HTTP (see HTTP above).
  2. The client receives the requested webpage and executes the JavaScript on the page which requests a file from the server.
  3. The server does not immediately respond with the requested information but waits until there's new information available.
  4. When there's new information available, the server responds with the new information.
  5. The client receives the new information and immediately sends another request to the server, re-starting the process.

Ajax Long-Polling

HTML5 Server Sent Events (SSE) / EventSource:

  1. A client requests a webpage from a server using regular HTTP (see HTTP above).
  2. The client receives the requested webpage and executes the JavaScript on the page which opens a connection to the server.
  3. The server sends an event to the client when there's new information available.

HTML5 SSE

HTML5 Websockets:

  1. A client requests a webpage from a server using regular http (see HTTP above).
  2. The client receives the requested webpage and executes the JavaScript on the page which opens a connection with the server.
  3. The server and the client can now send each other messages when new data (on either side) is available.

    • Real-time traffic from the server to the client and from the client to the server
    • You'll want to use a server that has an event loop
    • With WebSockets it is possible to connect with a server from another domain.
    • It is also possible to use a third party hosted websocket server, for example Pusher or others. This way you'll only have to implement the client side, which is very easy!
    • If you want to read more, I found these very useful: (article), (article) (tutorial).

HTML5 WebSockets

Comet:

Comet is a collection of techniques prior to HTML5 which use streaming and long-polling to achieve real time applications. Read more on wikipedia or this article.


Now, which one of them should I use for a realtime app (that I need to code). I have been hearing a lot about websockets (with socket.io [a node.js library]) but why not PHP ?

You can use PHP with WebSockets, check out Ratchet.

Read an Excel file directly from a R script

Given the proliferation of different ways to read an Excel file in R and the plethora of answers here, I thought I'd try to shed some light on which of the options mentioned here perform the best (in a few simple situations).

I myself have been using xlsx since I started using R, for inertia if nothing else, and I recently noticed there doesn't seem to be any objective information about which package works better.

Any benchmarking exercise is fraught with difficulties as some packages are sure to handle certain situations better than others, and a waterfall of other caveats.

That said, I'm using a (reproducible) data set that I think is in a pretty common format (8 string fields, 3 numeric, 1 integer, 3 dates):

set.seed(51423)
data.frame(
  str1 = sample(sprintf("%010d", 1:NN)), #ID field 1
  str2 = sample(sprintf("%09d", 1:NN)),  #ID field 2
  #varying length string field--think names/addresses, etc.
  str3 = 
    replicate(NN, paste0(sample(LETTERS, sample(10:30, 1L), TRUE),
                         collapse = "")),
  #factor-like string field with 50 "levels"
  str4 = sprintf("%05d", sample(sample(1e5, 50L), NN, TRUE)),
  #factor-like string field with 17 levels, varying length
  str5 = 
    sample(replicate(17L, paste0(sample(LETTERS, sample(15:25, 1L), TRUE),
                                 collapse = "")), NN, TRUE),
  #lognormally distributed numeric
  num1 = round(exp(rnorm(NN, mean = 6.5, sd = 1.5)), 2L),
  #3 binary strings
  str6 = sample(c("Y","N"), NN, TRUE),
  str7 = sample(c("M","F"), NN, TRUE),
  str8 = sample(c("B","W"), NN, TRUE),
  #right-skewed integer
  int1 = ceiling(rexp(NN)),
  #dates by month
  dat1 = 
    sample(seq(from = as.Date("2005-12-31"), 
               to = as.Date("2015-12-31"), by = "month"),
           NN, TRUE),
  dat2 = 
    sample(seq(from = as.Date("2005-12-31"), 
               to = as.Date("2015-12-31"), by = "month"),
           NN, TRUE),
  num2 = round(exp(rnorm(NN, mean = 6, sd = 1.5)), 2L),
  #date by day
  dat3 = 
    sample(seq(from = as.Date("2015-06-01"), 
               to = as.Date("2015-07-15"), by = "day"),
           NN, TRUE),
  #lognormal numeric that can be positive or negative
  num3 = 
    (-1) ^ sample(2, NN, TRUE) * round(exp(rnorm(NN, mean = 6, sd = 1.5)), 2L)
)

I then wrote this to csv and opened in LibreOffice and saved it as an .xlsx file, then benchmarked 4 of the packages mentioned in this thread: xlsx, openxlsx, readxl, and gdata, using the default options (I also tried a version of whether or not I specify column types, but this didn't change the rankings).

I'm excluding RODBC because I'm on Linux; XLConnect because it seems its primary purpose is not reading in single Excel sheets but importing entire Excel workbooks, so to put its horse in the race on only its reading capabilities seems unfair; and xlsReadWrite because it is no longer compatible with my version of R (seems to have been phased out).

I then ran benchmarks with NN=1000L and NN=25000L (resetting the seed before each declaration of the data.frame above) to allow for differences with respect to Excel file size. gc is primarily for xlsx, which I've found at times can create memory clogs. Without further ado, here are the results I found:

1,000-Row Excel File

benchmark1k <-
  microbenchmark(times = 100L,
                 xlsx = {xlsx::read.xlsx2(fl, sheetIndex=1); invisible(gc())},
                 openxlsx = {openxlsx::read.xlsx(fl); invisible(gc())},
                 readxl = {readxl::read_excel(fl); invisible(gc())},
                 gdata = {gdata::read.xls(fl); invisible(gc())})

# Unit: milliseconds
#      expr       min        lq      mean    median        uq       max neval
#      xlsx  194.1958  199.2662  214.1512  201.9063  212.7563  354.0327   100
#  openxlsx  142.2074  142.9028  151.9127  143.7239  148.0940  255.0124   100
#    readxl  122.0238  122.8448  132.4021  123.6964  130.2881  214.5138   100
#     gdata 2004.4745 2042.0732 2087.8724 2062.5259 2116.7795 2425.6345   100

So readxl is the winner, with openxlsx competitive and gdata a clear loser. Taking each measure relative to the column minimum:

#       expr   min    lq  mean median    uq   max
# 1     xlsx  1.59  1.62  1.62   1.63  1.63  1.65
# 2 openxlsx  1.17  1.16  1.15   1.16  1.14  1.19
# 3   readxl  1.00  1.00  1.00   1.00  1.00  1.00
# 4    gdata 16.43 16.62 15.77  16.67 16.25 11.31

We see my own favorite, xlsx is 60% slower than readxl.

25,000-Row Excel File

Due to the amount of time it takes, I only did 20 repetitions on the larger file, otherwise the commands were identical. Here's the raw data:

# Unit: milliseconds
#      expr        min         lq       mean     median         uq        max neval
#      xlsx  4451.9553  4539.4599  4738.6366  4762.1768  4941.2331  5091.0057    20
#  openxlsx   962.1579   981.0613   988.5006   986.1091   992.6017  1040.4158    20
#    readxl   341.0006   344.8904   347.0779   346.4518   348.9273   360.1808    20
#     gdata 43860.4013 44375.6340 44848.7797 44991.2208 45251.4441 45652.0826    20

Here's the relative data:

#       expr    min     lq   mean median     uq    max
# 1     xlsx  13.06  13.16  13.65  13.75  14.16  14.13
# 2 openxlsx   2.82   2.84   2.85   2.85   2.84   2.89
# 3   readxl   1.00   1.00   1.00   1.00   1.00   1.00
# 4    gdata 128.62 128.67 129.22 129.86 129.69 126.75

So readxl is the clear winner when it comes to speed. gdata better have something else going for it, as it's painfully slow in reading Excel files, and this problem is only exacerbated for larger tables.

Two draws of openxlsx are 1) its extensive other methods (readxl is designed to do only one thing, which is probably part of why it's so fast), especially its write.xlsx function, and 2) (more of a drawback for readxl) the col_types argument in readxl only (as of this writing) accepts some nonstandard R: "text" instead of "character" and "date" instead of "Date".

How do I import a .dmp file into Oracle?

I am Using Oracle Database Express Edition 11g Release 2.

Follow the Steps:

Open run SQl Command Line

Step 1: Login as system user

       SQL> connect system/tiger

Step 2 : SQL> CREATE USER UserName IDENTIFIED BY Password;

Step 3 : SQL> grant dba to UserName ;

Step 4 : SQL> GRANT UNLIMITED TABLESPACE TO UserName;

Step 5:

        SQL> CREATE BIGFILE TABLESPACE TSD_UserName
             DATAFILE 'tbs_perm_03.dat'
             SIZE 8G
             AUTOEXTEND ON;

Open Command Prompt in Windows or Terminal in Ubuntu. Then Type:

Note : if you Use Ubuntu then replace " \" to " /" in path.

Step 6: C:\> imp UserName/password@localhost file=D:\abc\xyz.dmp log=D:\abc\abc_1.log full=y;

Done....

I hope you Find Right solution here.

Thanks.

CertificateException: No name matching ssl.someUrl.de found

I've found a good resolution here: http://www.mkyong.com/webservices/jax-ws/java-security-cert-certificateexception-no-name-matching-localhost-found/

But my problem was a little bit different and solved it differently.

The web service was on remote host. For example: https://some.remote.host/MyWebService?wsdl

But it was available only by IP for any clients, but certificate was created for domain: some.remote.host (CN=some.remote.host). And this domain can't be resolved by IP because it is not presented in DNS).

So the same problem appeared: if I use IP to connect to web service by ssl, it can't be reached becase certificate CN=some.remote.host and it is not equal to host name I've specified (i.e. host IP).

I've resolved it by matching this hostname with IP in /etc/hosts file. The problem was fixed.

But in case when the Web Service is hosted on localhost app server, it think, it should be solved like mkyong described in his article.

Javascript to open popup window and disable parent window

This is how I finally did it! You can put a layer (full sized) over your body with high z-index and, of course hidden. You will make it visible when the window is open, make it focused on click over parent window (the layer), and finally will disappear it when the opened window is closed or submitted or whatever.

      .layer
  {
        position: fixed;
        opacity: 0.7;
        left: 0px;
        top: 0px;
        width: 100%;
        height: 100%;
        z-index: 999999;
        background-color: #BEBEBE;
        display: none;
        cursor: not-allowed;
  }

and layer in the body:

                <div class="layout" id="layout"></div>

function that opens the popup window:

    var new_window;
    function winOpen(){
        $(".layer").show();
        new_window=window.open(srcurl,'','height=750,width=700,left=300,top=200');
    }

keeping new window focused:

         $(document).ready(function(){
             $(".layout").click(function(e) {
                new_window.focus();
            }
        });

and in the opened window:

    function submit(){
        var doc = window.opener.document,
        doc.getElementById("layer").style.display="none";
         window.close();
    }   

   window.onbeforeunload = function(){
        var doc = window.opener.document;
        doc.getElementById("layout").style.display="none";
   }

I hope it would help :-)

Making TextView scrollable on Android

whenever you need to use the ScrollView as parent, And you also use the scroll movement method with TextView.

And When you portrait to landscape your device that time occur some issue. (like) entire page is scrollable but scroll movement method can't work.

if you still need to use ScrollView as parent or scroll movement method then you also use below desc.

If you do not have any problems then you use EditText instead of TextView

see below :

<EditText
     android:id="@+id/description_text_question"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:background="@null"
     android:editable="false"
     android:cursorVisible="false"
     android:maxLines="6"/>

Here, the EditText behaves like TextView

And your issue will be resolved

SyntaxError: cannot assign to operator

Python is upset because you are attempting to assign a value to something that can't be assigned a value.

((t[1])/length) * t[1] += string

When you use an assignment operator, you assign the value of what is on the right to the variable or element on the left. In your case, there is no variable or element on the left, but instead an interpreted value: you are trying to assign a value to something that isn't a "container".

Based on what you've written, you're just misunderstanding how this operator works. Just switch your operands, like so.

string += str(((t[1])/length) * t[1])

Note that I've wrapped the assigned value in str in order to convert it into a str so that it is compatible with the string variable it is being assigned to. (Numbers and strings can't be added together.)

Error loading the SDK when Eclipse starts

Working fine after removing the Android Wear ARM EABI v7a system image and wear intel x86 Atom System image.

ArrayList initialization equivalent to array initialization

Arrays.asList("Ryan", "Julie", "Bob");

R Language: How to print the first or last rows of a data set?

If you want to print the last 10 lines, use

tail(dataset, 10)

for the first 10, you could also do

head(dataset, 10)

How do I get total physical memory size using PowerShell without WMI?

Id like to say that instead of going with the systeminfo this would help over to get the total physical memory in GB's the machine

Get-CimInstance Win32_PhysicalMemory | Measure-Object -Property capacity -Sum | Foreach {"{0:N2}" -f ([math]::round(($_.Sum / 1GB),2))}

you can pass this value to the variable and get the gross output for the total physical memory in the machine

   $totalmemory = Get-CimInstance Win32_PhysicalMemory | Measure-Object -Property capacity -Sum | Foreach {"{0:N2}" -f ([math]::round(($_.Sum / 1GB),2))}
   $totalmemory

How to get rows count of internal table in abap?

There is also a built-in function for this task:

variable = lines( itab_name ).

Just like the "pure" ABAP syntax described by IronGoofy, the function "lines( )" writes the number of lines of table itab_name into the variable.

Regarding Java switch statements - using return and omitting breaks in each case

I suggest you not use literals.

Other than that the style itself looks fine.

Django set field value after a form is initialized

If you've already initialized the form, you can use the initial property of the field. For example,

form = CustomForm()
form.fields["Email"].initial = GetEmailString()

Group by month and year in MySQL

SELECT MONTHNAME(t.summaryDateTime) as month, YEAR(t.summaryDateTime) as year
FROM trading_summary t
GROUP BY YEAR(t.summaryDateTime) DESC, MONTH(t.summaryDateTime) DESC

Should use DESC for both YEAR and Month to get correct order.

Is there a way to run Bash scripts on Windows?

Best option? Windows 10. Native Bash support!

Escape string for use in Javascript regex

Short 'n Sweet

function escapeRegExp(string) {
  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}

Example

escapeRegExp("All of these should be escaped: \ ^ $ * + ? . ( ) | { } [ ]");

>>> "All of these should be escaped: \\ \^ \$ \* \+ \? \. \( \) \| \{ \} \[ \] "

(NOTE: the above is not the original answer; it was edited to show the one from MDN. This means it does not match what you will find in the code in the below npm, and does not match what is shown in the below long answer. The comments are also now confusing. My recommendation: use the above, or get it from MDN, and ignore the rest of this answer. -Darren,Nov 2019)

Install

Available on npm as escape-string-regexp

npm install --save escape-string-regexp

Note

See MDN: Javascript Guide: Regular Expressions

Other symbols (~`!@# ...) MAY be escaped without consequence, but are not required to be.

.

.

.

.

Test Case: A typical url

escapeRegExp("/path/to/resource.html?search=query");

>>> "\/path\/to\/resource\.html\?search=query"

The Long Answer

If you're going to use the function above at least link to this stack overflow post in your code's documentation so that it doesn't look like crazy hard-to-test voodoo.

var escapeRegExp;

(function () {
  // Referring to the table here:
  // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/regexp
  // these characters should be escaped
  // \ ^ $ * + ? . ( ) | { } [ ]
  // These characters only have special meaning inside of brackets
  // they do not need to be escaped, but they MAY be escaped
  // without any adverse effects (to the best of my knowledge and casual testing)
  // : ! , = 
  // my test "~!@#$%^&*(){}[]`/=?+\|-_;:'\",<.>".match(/[\#]/g)

  var specials = [
        // order matters for these
          "-"
        , "["
        , "]"
        // order doesn't matter for any of these
        , "/"
        , "{"
        , "}"
        , "("
        , ")"
        , "*"
        , "+"
        , "?"
        , "."
        , "\\"
        , "^"
        , "$"
        , "|"
      ]

      // I choose to escape every character with '\'
      // even though only some strictly require it when inside of []
    , regex = RegExp('[' + specials.join('\\') + ']', 'g')
    ;

  escapeRegExp = function (str) {
    return str.replace(regex, "\\$&");
  };

  // test escapeRegExp("/path/to/res?search=this.that")
}());

Android button with icon and text

@Liem Vo's answer is correct if you are using android.widget.Button without any overriding. If you are overriding your theme using MaterialComponents, this will not solve the issue.

So if you are

  1. Using com.google.android.material.button.MaterialButton or
  2. Overriding AppTheme using MaterialComponents

Use app:icon parameter.

<Button
    android:id="@+id/bSearch"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="16dp"
    android:text="Search"
    android:textSize="24sp"
    app:icon="@android:drawable/ic_menu_search" />

Remove All Event Listeners of Specific Type

 var events = [event_1, event_2,event_3]  // your events

//make a for loop of your events and remove them all in a single instance

 for (let i in events){
    canvas_1.removeEventListener("mousedown", events[i], false)
}

Resolving tree conflict

What you can do to resolve your conflict is

svn resolve --accept working -R <path>

where <path> is where you have your conflict (can be the root of your repo).

Explanations:

  • resolve asks svn to resolve the conflict
  • accept working specifies to keep your working files
  • -R stands for recursive

Hope this helps.

EDIT:

To sum up what was said in the comments below:

  • <path> should be the directory in conflict (C:\DevBranch\ in the case of the OP)
  • it's likely that the origin of the conflict is
    • either the use of the svn switch command
    • or having checked the Switch working copy to new branch/tag option at branch creation
  • more information about conflicts can be found in the dedicated section of Tortoise's documentation.
  • to be able to run the command, you should have the CLI tools installed together with Tortoise:

Command line client tools

How to check if running in Cygwin, Mac or Linux?

# This script fragment emits Cygwin rulez under bash/cygwin
if [[ $(uname -s) == CYGWIN* ]];then
    echo Cygwin rulez
else 
    echo Unix is king
fi

If the 6 first chars of uname -s command is "CYGWIN", a cygwin system is assumed

Submitting a form on 'Enter' with jQuery?

Also to maintain accessibility, you should use this to determine your keycode:

c = e.which ? e.which : e.keyCode;

if (c == 13) ...

Practical uses for the "internal" keyword in C#

How about this one: typically it is recommended that you do not expose a List object to external users of an assembly, rather expose an IEnumerable. But it is lot easier to use a List object inside the assembly, because you get the array syntax, and all other List methods. So, I typically have a internal property exposing a List to be used inside the assembly.

Comments are welcome about this approach.

How to count days between two dates in PHP?

In case your DateTime has also hour:minutes:seconds and you still want to have the number of days..

   /**
     * Returns the total number of days between to DateTimes, 
     * if it is within the same year
     * @param $start
     * @param $end
     */
    public function dateTimesToDays($start,$end){
       return intval($end->format('z')) - intval($start->format('z')) + 1;
    }

https://github.com/dukeatcoding/timespan-converter

SQL Logic Operator Precedence: And and Or

  1. Arithmetic operators
  2. Concatenation operator
  3. Comparison conditions
  4. IS [NOT] NULL, LIKE, [NOT] IN
  5. [NOT] BETWEEN
  6. Not equal to
  7. NOT logical condition
  8. AND logical condition
  9. OR logical condition

You can use parentheses to override rules of precedence.

Angular 4: no component factory found,did you add it to @NgModule.entryComponents?

I had same issue in Angular7 when I create dynamic components. There are two components(TreatListComponent, MyTreatComponent) that needs to be loaded dynamically. I just added entryComponents array in to my app.module.ts file.

    entryComponents: [
    TreatListComponent,
    MyTreatComponent
  ],

Matplotlib - Move X-Axis label downwards, but not X-Axis Ticks

use labelpad parameter:

pl.xlabel("...", labelpad=20)

or set it after:

ax.xaxis.labelpad = 20

Why are static variables considered evil?

a) Reason about programs.

If you have a small- to midsize-program, where the static variable Global.foo is accessed, the call to it normally comes from nowhere - there is no path, and therefore no timeline, how the variable comes to the place, where it is used. Now how do I know who set it to its actual value? How do I know, what happens, if I modify it right now? I have grep over the whole source, to collect all accesses, to know, what is going on.

If you know how you use it, because you just wrote the code, the problem is invisible, but if you try to understand foreign code, you will understand.

b) Do you really only need one?

Static variables often prevent multiple programs of the same kind running in the same JVM with different values. You often don't foresee usages, where more than one instance of your program is useful, but if it evolves, or if it is useful for others, they might experience situations, where they would like to start more than one instance of your program.

Only more or less useless code which will not be used by many people over a longer time in an intensive way might go well with static variables.

How to get all keys with their values in redis

Tried the given example, but over VPN and with 400k+ keys it was too slow for me. Also it did not give me the key objects.

I wrote a small Python called tool redis-mass-get to combine KEYS and MGET requests against Redis:

# installation:
pip install redis-mass-get

# pipeline example CSV:
redis-mass-get -f csv -och redis://my.redis.url product:* | less

# write to json-file example with progress indicator:
redis-mass-get -d results.json -jd redis://my.redis.url product:*

It supports JSON, CSV and TXT output to file or stdout for usage in pipes. More info can be found at: Reading multiple key/values from Redis.

Python Hexadecimal

I think this is what you want:

>>> def twoDigitHex( number ):
...     return '%02x' % number
... 
>>> twoDigitHex( 2 )
'02'
>>> twoDigitHex( 255 )
'ff'

python 2.7: cannot pip on windows "bash: pip: command not found"

If this is for Cygwin, it installs "pip" as "pip2". Just create a softlink to "pip2" in the same location where "pip2" is installed.

Is there an equivalent to background-size: cover and contain for image elements?

I know this is old, however many solutions I see above have an issue with the image/video being too large for the container so not actually acting like background-size cover. However, I decided to make "utility classes" so that it would work for images and videos. You simply give the container the class .media-cover-wrapper and the media item itself the class .media-cover

Then you have the following jQuery:

function adjustDimensions(item, minW, minH, maxW, maxH) {
  item.css({
  minWidth: minW,
  minHeight: minH,
  maxWidth: maxW,
  maxHeight: maxH
  });
} // end function adjustDimensions

function mediaCoverBounds() {
  var mediaCover = $('.media-cover');

  mediaCover.each(function() {
   adjustDimensions($(this), '', '', '', '');
   var mediaWrapper = $(this).parent();
   var mediaWrapperWidth = mediaWrapper.width();
   var mediaWrapperHeight = mediaWrapper.height();
   var mediaCoverWidth = $(this).width();
   var mediaCoverHeight = $(this).height();
   var maxCoverWidth;
   var maxCoverHeight;

   if (mediaCoverWidth > mediaWrapperWidth && mediaCoverHeight > mediaWrapperHeight) {

     if (mediaWrapperHeight/mediaWrapperWidth > mediaCoverHeight/mediaCoverWidth) {
       maxCoverWidth = '';
       maxCoverHeight = '100%';
     } else {
       maxCoverWidth = '100%';
       maxCoverHeight = '';
     } // end if

     adjustDimensions($(this), '', '', maxCoverWidth, maxCoverHeight);
   } else {
     adjustDimensions($(this), '100%', '100%', '', '');
   } // end if
 }); // end mediaCover.each
} // end function mediaCoverBounds

When calling it make sure to take care of page resizing:

mediaCoverBounds();

$(window).on('resize', function(){
  mediaCoverBounds();
});

Then the following CSS:

.media-cover-wrapper {
  position: relative;
  overflow: hidden;
}

.media-cover-wrapper .media-cover {
  position: absolute;
  z-index: -1;
  top: 50%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  -moz-transform: translate(-50%, -50%);
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

Yeah it may require jQuery but it responds quite well and acts exactly like background-size: cover and you can use it on image and/or videos to get that extra SEO value.

What EXACTLY is meant by "de-referencing a NULL pointer"?

Quoting from wikipedia:

A pointer references a location in memory, and obtaining the value at the location a pointer refers to is known as dereferencing the pointer.

Dereferencing is done by applying the unary * operator on the pointer.

int x = 5;
int * p;      // pointer declaration
p = &x;       // pointer assignment
*p = 7;       // pointer dereferencing, example 1
int y = *p;   // pointer dereferencing, example 2

"Dereferencing a NULL pointer" means performing *p when the p is NULL

Displaying one div on top of another

Use CSS position: absolute; followed by top: 0px; left 0px; in the style attribute of each DIV. Replace the pixel values with whatever you want.

You can use z-index: x; to set the vertical "order" (which one is "on top"). Replace x with a number, higher numbers are on top of lower numbers.

Here is how your new code would look:

<div>
  <div id="backdrop" style="z-index: 1; position: absolute; top: 0px; left: 0px;"><img alt="" src='/backdrop.png' /></div>
  <div id="curtain" style="z-index: 2; position: absolute; top: 0px; left: 0px; background-image:url(/curtain.png);background-position:100px 200px; height:250px; width:500px;">&nbsp;</div>
</div>

Converting a PDF to PNG

One can also use the command line utilities included in poppler-utils package:

sudo apt-get install poppler-utils
pdftoppm --help
pdftocairo --help

Example:

pdftocairo -png mypage.pdf mypage.png

How to convert a 3D point into 2D perspective projection?

You can project 3D point in 2D using: Commons Math: The Apache Commons Mathematics Library with just two classes.

Example for Java Swing.

import org.apache.commons.math3.geometry.euclidean.threed.Plane;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;


Plane planeX = new Plane(new Vector3D(1, 0, 0));
Plane planeY = new Plane(new Vector3D(0, 1, 0)); // Must be orthogonal plane of planeX

void drawPoint(Graphics2D g2, Vector3D v) {
    g2.drawLine(0, 0,
            (int) (world.unit * planeX.getOffset(v)),
            (int) (world.unit * planeY.getOffset(v)));
}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);

    drawPoint(g2, new Vector3D(2, 1, 0));
    drawPoint(g2, new Vector3D(0, 2, 0));
    drawPoint(g2, new Vector3D(0, 0, 2));
    drawPoint(g2, new Vector3D(1, 1, 1));
}

Now you only needs update the planeX and planeY to change the perspective-projection, to get things like this:

enter image description hereenter image description here

Replace one character with another in Bash

Use parameter substitution:

string=${string// /.}

Getting the HTTP Referrer in ASP.NET

I'm using .Net Core 2 mvc, this one work for me ( to get the previews page) :

HttpContext.Request.Headers["Referer"];

MySQL Check if username and password matches in Database

1.) Storage of database passwords Use some kind of hash with a salt and then alter the hash, obfuscate it, for example add a distinct value for each byte. That way your passwords a super secured against dictionary attacks and rainbow tables.

2.) To check if the password matches, create your hash for the password the user put in. Then perform a query against the database for the username and just check if the two password hashes are identical. If they are, give the user an authentication token.

The query should then look like this:

select hashedPassword from users where username=?

Then compare the password to the input.

Further questions?

How to get EditText value and display it on screen through TextView?

bb.setOnClickListener(
    new View.OnClickListener()
    {
        public void onClick(View view)
        {
            String s1=tt.getText().toString();
            tv.setText(s1);
        }
    }
);

Clear back stack using fragments

Reading the documentation and studying what the fragment id is, it appears to simply be the stack index, so this works:

fragmentManager.popBackStackImmediate(0, FragmentManager.POP_BACK_STACK_INCLUSIVE);

Zero (0) is the the bottom of the stack, so popping up to it inclusive clears the stack.

CAVEAT: Although the above works in my program, I hesitate a bit because the FragmentManager documentation never actually states that the id is the stack index. It makes sense that it would be, and all my debug logs bare out that it is, but perhaps in some special circumstance it would not? Can any one confirm this one way or the other? If it is, then the above is the best solution. If not, this is the alternative:

while(fragmentManager.getBackStackEntryCount() > 0) { fragmentManager.popBackStackImmediate(); }

Succeeded installing but could not start apache 2.4 on my windows 7 system

I have the same problem too, after upgrading win7 to win10. then I check services.msc and found "World Wide Web Publishing Service" was running automatically by default. So then I disabled it, and running the Apache service again.

How can I get key's value from dictionary in Swift?

For finding value use below

if let a = companies["AAPL"] {
   // a is the value
}

For traversing through the dictionary

for (key, value) in companies {
    print(key,"---", value)
}

Finally for searching key by value you firstly add the extension

extension Dictionary where Value: Equatable {
    func findKey(forValue val: Value) -> Key? {
        return first(where: { $1 == val })?.key
    }
}

Then just call

companies.findKey(val : "Apple Inc")

Calling async method synchronously

Well I am using this approach:

    private string RunSync()
    {
        var task = Task.Run(async () => await GenerateCodeService.GenerateCodeAsync());
        if (task.IsFaulted && task.Exception != null)
        {
            throw task.Exception;
        }

        return task.Result;
    }

How to run a command in the background and get no output?

Use nohup if your background job takes a long time to finish or you just use SecureCRT or something like it login the server.

Redirect the stdout and stderr to /dev/null to ignore the output.

nohup /path/to/your/script.sh > /dev/null 2>&1 &

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

real-time - Pertaining to a system or mode of operation in which computation is performed during the actual time that an external process occurs, in order that the computation results can be used to control, monitor, or respond to the external process in a timely manner. [IEEE Standard 610.12.1990]

I know this definition is old, very old. I can't, however, find a more recent definition by the IEEE (Institute of Electrical and Electronics Engineers).

operator << must take exactly one argument

If you define operator<< as a member function it will have a different decomposed syntax than if you used a non-member operator<<. A non-member operator<< is a binary operator, where a member operator<< is a unary operator.

// Declarations
struct MyObj;
std::ostream& operator<<(std::ostream& os, const MyObj& myObj);

struct MyObj
{
    // This is a member unary-operator, hence one argument
    MyObj& operator<<(std::ostream& os) { os << *this; return *this; }

    int value = 8;
};

// This is a non-member binary-operator, 2 arguments
std::ostream& operator<<(std::ostream& os, const MyObj& myObj)
{
    return os << myObj.value;
}

So.... how do you really call them? Operators are odd in some ways, I'll challenge you to write the operator<<(...) syntax in your head to make things make sense.

MyObj mo;

// Calling the unary operator
mo << std::cout;

// which decomposes to...
mo.operator<<(std::cout);

Or you could attempt to call the non-member binary operator:

MyObj mo;

// Calling the binary operator
std::cout << mo;

// which decomposes to...
operator<<(std::cout, mo);

You have no obligation to make these operators behave intuitively when you make them into member functions, you could define operator<<(int) to left shift some member variable if you wanted to, understand that people may be a bit caught off guard, no matter how many comments you may write.

Almost lastly, there may be times where both decompositions for an operator call are valid, you may get into trouble here and we'll defer that conversation.

Lastly, note how odd it might be to write a unary member operator that is supposed to look like a binary operator (as you can make member operators virtual..... also attempting to not devolve and run down this path....)

struct MyObj
{
    // Note that we now return the ostream
    std::ostream& operator<<(std::ostream& os) { os << *this; return os; }

    int value = 8;
};

This syntax will irritate many coders now....

MyObj mo;

mo << std::cout << "Words words words";

// this decomposes to...
mo.operator<<(std::cout) << "Words words words";

// ... or even further ...
operator<<(mo.operator<<(std::cout), "Words words words");

Note how the cout is the second argument in the chain here.... odd right?

Bootstrap modal - close modal when "call to action" button is clicked

Make as shown.

_x000D_
_x000D_
  $(document).ready(function(){_x000D_
    $('#myModal').modal('show');_x000D_
_x000D_
    $('#myBtn').on('click', function(){_x000D_
      $('#myModal').modal('show');_x000D_
    });_x000D_
    _x000D_
  });_x000D_
<br/>_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
<head>_x000D_
  <title>Bootstrap Example</title>_x000D_
  <meta charset="utf-8">_x000D_
  <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">_x000D_
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
</head>_x000D_
<body>_x000D_
_x000D_
<div class="container">_x000D_
  <h2>Activate Modal with JavaScript</h2>_x000D_
  <!-- Trigger the modal with a button -->_x000D_
  <button type="button" class="btn btn-info btn-lg" id="myBtn">Open Modal</button>_x000D_
_x000D_
  <!-- Modal -->_x000D_
  <div class="modal fade" id="myModal" role="dialog">_x000D_
    <div class="modal-dialog">_x000D_
    _x000D_
      <!-- Modal content-->_x000D_
      <div class="modal-content">_x000D_
        <div class="modal-header">_x000D_
          <button type="button" class="close" data-dismiss="modal">&times;</button>_x000D_
          <h4 class="modal-title">Modal Header</h4>_x000D_
        </div>_x000D_
        <div class="modal-body">_x000D_
          <p>Some text in the modal.</p>_x000D_
        </div>_x000D_
_x000D_
      </div>_x000D_
      _x000D_
    </div>_x000D_
  </div>_x000D_
  _x000D_
</div>
_x000D_
_x000D_
_x000D_

Positive Number to Negative Number in JavaScript?

If you don't feel like using Math.Abs * -1 you can you this simple if statement :P

if (x > 0) {
    x = -x;
}

Of course you could make this a function like this

function makeNegative(number) {
    if (number > 0) {
        number = -number;
    }
}

makeNegative(-3) => -3 makeNegative(5) => -5

Hope this helps! Math.abs will likely work for you but if it doesn't this little

how to write an array to a file Java

private static void saveArrayToFile(String fileName, int[] array) throws IOException {
    Files.write( // write to file
        Paths.get(fileName), // get path from file
        Collections.singleton(Arrays.toString(array)), // transform array to collection using singleton
        Charset.forName("UTF-8") // formatting
    );
}

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

This works for me on Mac OS Mojave:

<Directory "/Users/{USERNAME}/Sites/project">
    Options +Indexes +FollowSymLinks +MultiViews
    AllowOverride All
    require all granted
</Directory>

How to terminate a process in vbscript

The Win32_Process class provides access to both 32-bit and 64-bit processes when the script is run from a 64-bit command shell.

If this is not an option for you, you can try using the taskkill command:

Dim oShell : Set oShell = CreateObject("WScript.Shell")

' Launch notepad '
oShell.Run "notepad"
WScript.Sleep 3000

' Kill notepad '
oShell.Run "taskkill /im notepad.exe", , True

Getting the last element of a list

lst[-1] is the best approach, but with general iterables, consider more_itertools.last:

Code

import more_itertools as mit


mit.last([0, 1, 2, 3])
# 3

mit.last(iter([1, 2, 3]))
# 3

mit.last([], "some default")
# 'some default'

Why does JSON.parse fail with the empty string?

JSON.parse expects valid notation inside a string, whether that be object {}, array [], string "" or number types (int, float, doubles).

If there is potential for what is parsing to be an empty string then the developer should check for it.

If it was built into the function it would add extra cycles, since built in functions are expected to be extremely performant, it makes sense to not program them for the race case.

Using BufferedReader to read Text File

This is the problem:

while (br.readLine() != null) {
    System.out.println(br.readLine());
}

You've got two calls to readLine - the first only checks that there's a line (but reads it and throws it away) and the second reads the next line. You want:

String line;
while ((line = br.readLine()) != null) {
    System.out.println(line);
}

Now we're only calling readLine() once per loop iteration, and using the line that we've read both for the "have we finished?" and "print out the line" parts.

How to style a div to be a responsive square?

It is as easy as specifying a padding bottom the same size as the width in percent. So if you have a width of 50%, just use this example below

id or class{
    width: 50%;
    padding-bottom: 50%;
}

Here is a jsfiddle http://jsfiddle.net/kJL3u/2/

Edited version with responsive text: http://jsfiddle.net/kJL3u/394

How to change position of Toast in Android?

From the documentation,

Positioning your Toast

A standard toast notification appears near the bottom of the screen, centered horizontally. You can change this position with the setGravity(int, int, int) method. This accepts three parameters: a Gravity constant, an x-position offset, and a y-position offset.

For example, if you decide that the toast should appear in the top-left corner, you can set the gravity like this:

toast.setGravity(Gravity.TOP|Gravity.LEFT, 0, 0);

If you want to nudge the position to the right, increase the value of the second parameter. To nudge it down, increase the value of the last parameter.

Can you use @Autowired with static fields?

Wanted to add to answers that auto wiring static field (or constant) will be ignored, but also won't create any error:

@Autowired
private static String staticField = "staticValue";

How to connect to mysql with laravel?

I spent a lot of time trying to figure this one out. Finally, I tried shutting down my development server and booting it up again. Frustratingly, this worked for me. I came to the conclusion, that after editing the .env file in Laravel 5, you have to exit the server, and run php artisan serve again.

Python List & for-each access (Find/Replace in built-in list)

Python is not Java, nor C/C++ -- you need to stop thinking that way to really utilize the power of Python.

Python does not have pass-by-value, nor pass-by-reference, but instead uses pass-by-name (or pass-by-object) -- in other words, nearly everything is bound to a name that you can then use (the two obvious exceptions being tuple- and list-indexing).

When you do spam = "green", you have bound the name spam to the string object "green"; if you then do eggs = spam you have not copied anything, you have not made reference pointers; you have simply bound another name, eggs, to the same object ("green" in this case). If you then bind spam to something else (spam = 3.14159) eggs will still be bound to "green".

When a for-loop executes, it takes the name you give it, and binds it in turn to each object in the iterable while running the loop; when you call a function, it takes the names in the function header and binds them to the arguments passed; reassigning a name is actually rebinding a name (it can take a while to absorb this -- it did for me, anyway).

With for-loops utilizing lists, there are two basic ways to assign back to the list:

for i, item in enumerate(some_list):
    some_list[i] = process(item)

or

new_list = []
for item in some_list:
    new_list.append(process(item))
some_list[:] = new_list

Notice the [:] on that last some_list -- it is causing a mutation of some_list's elements (setting the entire thing to new_list's elements) instead of rebinding the name some_list to new_list. Is this important? It depends! If you have other names besides some_list bound to the same list object, and you want them to see the updates, then you need to use the slicing method; if you don't, or if you do not want them to see the updates, then rebind -- some_list = new_list.

Send multiple checkbox data to PHP via jQuery ajax()

Check this out.

<script type="text/javascript">
    function submitForm() {
$(document).ready(function() {
$("form#myForm").submit(function() {

        var myCheckboxes = new Array();
        $("input:checked").each(function() {
           myCheckboxes.push($(this).val());
        });

        $.ajax({
            type: "POST",
            url: "myurl.php",
            dataType: 'html',
            data: 'myField='+$("textarea[name=myField]").val()+'&myCheckboxes='+myCheckboxes,
            success: function(data){
                $('#myResponse').html(data)
            }
        });
        return false;
});
});
}
</script>

And on myurl.php you can use print_r($_POST['myCheckboxes']);

Codeigniter LIKE with wildcard(%)

If you do not want to use the wildcard (%) you can pass to the optional third argument the option 'none'.

$this->db->like('title', 'match', 'none'); 
// Produces: WHERE title LIKE 'match'

How can I prevent the backspace key from navigating back?

Sitepoint: Disable back for Javascript

event.stopPropagation() and event.preventDefault() do nothing in IE. I had to send return event.keyCode == 11 (I just picked something) instead of just saying "if not = 8, run the event" to make it work, though. event.returnValue = false also works.

What is the best way to insert source code examples into a Microsoft Word document?

There is an easy way if you want simple code formatting.

  1. Open word> Insert tab> click on "Get Add-ins"
  2. search for "Content mixer" 3.click on "Add"

Then content mixer add will open automatically and you can copy paste your code in there and click on "Insert" to insert it in word doc.

grep from tar.gz without extracting [faster one]

Am trying to grep pattern from dozen files .tar.gz but its very slow

tar -ztf file.tar.gz | while read FILENAME
do
        if tar -zxf file.tar.gz "$FILENAME" -O | grep "string" > /dev/null
        then
                echo "$FILENAME contains string"
        fi
done

That's actually very easy with ugrep option -z:

-z, --decompress
        Decompress files to search, when compressed.  Archives (.cpio,
        .pax, .tar, and .zip) and compressed archives (e.g. .taz, .tgz,
        .tpz, .tbz, .tbz2, .tb2, .tz2, .tlz, and .txz) are searched and
        matching pathnames of files in archives are output in braces.  If
        -g, -O, -M, or -t is specified, searches files within archives
        whose name matches globs, matches file name extensions, matches
        file signature magic bytes, or matches file types, respectively.
        Supported compression formats: gzip (.gz), compress (.Z), zip,
        bzip2 (requires suffix .bz, .bz2, .bzip2, .tbz, .tbz2, .tb2, .tz2),
        lzma and xz (requires suffix .lzma, .tlz, .xz, .txz).

Which requires just one command to search file.tar.gz as follows:

ugrep -z "string" file.tar.gz

This greps each of the archived files to display matches. Archived filenames are shown in braces to distinguish them from ordinary filenames. For example:

$ ugrep -z "Hello" archive.tgz
{Hello.bat}:echo "Hello World!"
Binary file archive.tgz{Hello.class} matches
{Hello.java}:public class Hello // prints a Hello World! greeting
{Hello.java}:  { System.out.println("Hello World!");
{Hello.pdf}:(Hello)
{Hello.sh}:echo "Hello World!"
{Hello.txt}:Hello

If you just want the file names, use option -l (--files-with-matches) and customize the filename output with option --format="%z%~" to get rid of the braces:

$ ugrep -z Hello -l --format="%z%~" archive.tgz
Hello.bat
Hello.class
Hello.java
Hello.pdf
Hello.sh
Hello.txt

CSS: How can I set image size relative to parent height?

Original Answer:

If you are ready to opt for CSS3, you can use css3 translate property. Resize based on whatever is bigger. If your height is bigger and width is smaller than container, width will be stretch to 100% and height will be trimmed from both side. Same goes for larger width as well.

Your need, HTML:

<div class="img-wrap">
  <img src="http://lorempixel.com/300/160/nature/" />
</div>
<div class="img-wrap">
  <img src="http://lorempixel.com/300/200/nature/" />
</div>
<div class="img-wrap">
  <img src="http://lorempixel.com/200/300/nature/" />
</div>

And CSS:

.img-wrap {
  width: 200px;
  height: 150px;
  position: relative;
  display: inline-block;
  overflow: hidden;
  margin: 0;
}

div > img {
  display: block;
  position: absolute;
  top: 50%;
  left: 50%;
  min-height: 100%;
  min-width: 100%;
  transform: translate(-50%, -50%);
}

Voila! Working: http://jsfiddle.net/shekhardesigner/aYrhG/

Explanation

DIV is set to the relative position. This means all the child elements will get the starting coordinates (origins) from where this DIV starts.

The image is set as a BLOCK element, min-width/height both set to 100% means to resize the image no matter of its size to be the minimum of 100% of it's parent. min is the key. If by min-height, the image height exceeded the parent's height, no problem. It will look for if min-width and try to set the minimum height to be 100% of parents. Both goes vice-versa. This ensures there are no gaps around the div but image is always bit bigger and gets trimmed by overflow:hidden;

Now image, this is set to an absolute position with left:50% and top:50%. Means push the image 50% from the top and left making sure the origin is taken from DIV. Left/Top units are measured from the parent.

Magic moment:

transform: translate(-50%, -50%);

Now, this translate function of CSS3 transform property moves/repositions an element in question. This property deals with the applied element hence the values (x, y) OR (-50%, -50%) means to move the image negative left by 50% of image size and move to the negative top by 50% of image size.

Eg. if Image size was 200px × 150px, transform:translate(-50%, -50%) will calculated to translate(-100px, -75px). % unit helps when we have various size of image.

This is just a tricky way to figure out centroid of the image and the parent DIV and match them.

Apologies for taking too long to explain!

Resources to read more:

Error :Request header field Content-Type is not allowed by Access-Control-Allow-Headers

As hinted at by this post Error in chrome: Content-Type is not allowed by Access-Control-Allow-Headers just add the additional header to your web.config like so...

<httpProtocol>
  <customHeaders>
    <add name="Access-Control-Allow-Origin" value="*" />
    <add name="Access-Control-Allow-Headers" value="Origin, X-Requested-With, Content-Type, Accept" />
  </customHeaders>
</httpProtocol>

Why am I getting an OPTIONS request instead of a GET request?

I was able to fix it with the help of following headers

Access-Control-Allow-Origin
Access-Control-Allow-Headers
Access-Control-Allow-Credentials
Access-Control-Allow-Methods

If you are on Nodejs, here is the code you can copy/paste.

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin','*');
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  res.header('Access-Control-Allow-Credentials', true);
  res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, PATCH');
  next();
});

'do...while' vs. 'while'

I ran across this while researching the proper loop to use for a situation I have. I believe this will fully satisfy a common situation where a do.. while loop is a better implementation than a while loop (C# language, since you stated that is your primary for work).

I am generating a list of strings based on the results of an SQL query. The returned object by my query is an SQLDataReader. This object has a function called Read() which advances the object to the next row of data, and returns true if there was another row. It will return false if there is not another row.

Using this information, I want to return each row to a list, then stop when there is no more data to return. A Do... While loop works best in this situation as it ensures that adding an item to the list will happen BEFORE checking if there is another row. The reason this must be done BEFORE checking the while(condition) is that when it checks, it also advances. Using a while loop in this situation would cause it to bypass the first row due to the nature of that particular function.

In short:

This won't work in my situation.

    //This will skip the first row because Read() returns true after advancing.
    while (_read.NextResult())
           {
               list.Add(_read.GetValue(0).ToString());
           }

   return list;

This will.

    //This will make sure the currently read row is added before advancing.
    do
        {
            list.Add(_read.GetValue(0).ToString());
        } 
        while (_read.NextResult());

    return list;

Clearing state es6 React

use deep copy, you can do it with lodash:

import _ from "lodash";

const INITIAL_STATE = {};

constructor(props) {
    super(props);
    this.state = _.cloneDeep(INITIAL_STATE);
}

reset() {
    this.setState(_.cloneDeep(INITIAL_STATE));
}

how to create a cookie and add to http response from inside my service layer?

A cookie is a object with key value pair to store information related to the customer. Main objective is to personalize the customer's experience.

An utility method can be created like

private Cookie createCookie(String cookieName, String cookieValue) {
    Cookie cookie = new Cookie(cookieName, cookieValue);
    cookie.setPath("/");
    cookie.setMaxAge(MAX_AGE_SECONDS);
    cookie.setHttpOnly(true);
    cookie.setSecure(true);
    return cookie;
}

If storing important information then we should alsways put setHttpOnly so that the cookie cannot be accessed/modified via javascript. setSecure is applicable if you are want cookies to be accessed only over https protocol.

using above utility method you can add cookies to response as

Cookie cookie = createCookie("name","value");
response.addCookie(cookie);

How can I specify the default JVM arguments for programs I run from eclipse?

Go to Window → Preferences → Java → Installed JREs. Select the JRE you're using, click Edit, and there will be a line for Default VM Arguments which will apply to every execution. For instance, I use this on OS X to hide the icon from the dock, increase max memory and turn on assertions:

-Xmx512m -ea -Djava.awt.headless=true

Exclude all transitive dependencies of a single dependency

Three years ago I recommended using Version 99 Does Not Exist, but now I've figured out a better way, especially since Version 99 is offline:

In your project's parent POM, use maven-enforcer-plugin to fail the build if the unwanted dependency creeps into the build. This can be done using the plugin's banned dependencies rule:

<plugin>
    <artifactId>maven-enforcer-plugin</artifactId>
    <version>1.0.1</version>
    <executions>
        <execution>
            <id>only-junit-dep-is-used</id>
            <goals>
                <goal>enforce</goal>
            </goals>
            <configuration>
                <rules>
                    <bannedDependencies>
                        <excludes>
                            <exclude>junit:junit</exclude>
                        </excludes>
                    </bannedDependencies>
                </rules>
            </configuration>
        </execution>
    </executions>
</plugin>

Then when that alerts you about an unwanted dependency, exclude it in the parent POM's <dependencyManagement> section:

<dependency>
    <groupId>org.springframework.batch</groupId>
    <artifactId>spring-batch-test</artifactId>
    <version>2.1.8.RELEASE</version>
    <exclusions>
        <exclusion>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </exclusion>
    </exclusions>
</dependency>

This way the unwanted dependency won't show up accidentally (unlike just an <exclusion> which is easy to forget), it won't be available even during compile time (unlike provided scope), there are no bogus dependencies (unlike Version 99) and it'll work without a custom repository (unlike Version 99). This approach will even work based on the artifact's version, classifiers, scope or a whole groupId - see the documentation for details.

Java Byte Array to String to Byte Array

You can't just take the returned string and construct a string from it... it's not a byte[] data type anymore, it's already a string; you need to parse it. For example :

String response = "[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]";      // response from the Python script

String[] byteValues = response.substring(1, response.length() - 1).split(",");
byte[] bytes = new byte[byteValues.length];

for (int i=0, len=bytes.length; i<len; i++) {
   bytes[i] = Byte.parseByte(byteValues[i].trim());     
}

String str = new String(bytes);

** EDIT **

You get an hint of your problem in your question, where you say "Whatever I seem to try I end up getting a byte array which looks as follows... [91, 45, ...", because 91 is the byte value for [, so [91, 45, ... is the byte array of the string "[-45, 1, 16, ..." string.

The method Arrays.toString() will return a String representation of the specified array; meaning that the returned value will not be a array anymore. For example :

byte[] b1 = new byte[] {97, 98, 99};

String s1 = Arrays.toString(b1);
String s2 = new String(b1);

System.out.println(s1);        // -> "[97, 98, 99]"
System.out.println(s2);        // -> "abc";

As you can see, s1 holds the string representation of the array b1, while s2 holds the string representation of the bytes contained in b1.

Now, in your problem, your server returns a string similar to s1, therefore to get the array representation back, you need the opposite constructor method. If s2.getBytes() is the opposite of new String(b1), you need to find the opposite of Arrays.toString(b1), thus the code I pasted in the first snippet of this answer.

#ifdef replacement in the Swift language

Yes you can do it.

In Swift you can still use the "#if/#else/#endif" preprocessor macros (although more constrained), as per Apple docs. Here's an example:

#if DEBUG
    let a = 2
#else
    let a = 3
#endif

Now, you must set the "DEBUG" symbol elsewhere, though. Set it in the "Swift Compiler - Custom Flags" section, "Other Swift Flags" line. You add the DEBUG symbol with the -D DEBUG entry.

As usual, you can set a different value when in Debug or when in Release.

I tested it in real code and it works; it doesn't seem to be recognized in a playground though.

You can read my original post here.


IMPORTANT NOTE: -DDEBUG=1 doesn't work. Only -D DEBUG works. Seems compiler is ignoring a flag with a specific value.

Which Radio button in the group is checked?

The OP wanted to get the checked RadioButton BY GROUP. While @SLaks' answer is excellent, it doesn't really answer the OP's main question. To improve on @SLaks' answer, just take the LINQ one step further.

Here's an example from my own working code. Per normal WPF, my RadioButtons are contained in a Grid (named "myGrid") with a bunch of other types of controls. I have two different RadioButton groups in the Grid.

To get the checked RadioButton from a particular group:

List<RadioButton> radioButtons = myGrid.Children.OfType<RadioButton>().ToList();
RadioButton rbTarget = radioButtons
      .Where(r => r.GroupName == "GroupName" && r.IsChecked)
      .Single();

If your code has the possibility of no RadioButtons being checked, then use SingleOrDefault() (If I'm not using tri-state buttons, then I always set one button "IsChecked" as a default selection.)

How can I resize an image using Java?

Image Magick has been mentioned. There is a JNI front end project called JMagick. It's not a particularly stable project (and Image Magick itself has been known to change a lot and even break compatibility). That said, we've had good experience using JMagick and a compatible version of Image Magick in a production environment to perform scaling at a high throughput, low latency rate. Speed was substantially better then with an all Java graphics library that we previously tried.

http://www.jmagick.org/index.html

Random alpha-numeric string in JavaScript?

for 32 characters:

for(var c = ''; c.length < 32;) c += Math.random().toString(36).substr(2, 1)

How can I send mail from an iPhone application

This is the code which can help u but dont forget to include message ui framewark and include delegates method MFMailComposeViewControllerDelegate

-(void)EmailButtonACtion{

        if ([MFMailComposeViewController canSendMail])
        {
            MFMailComposeViewController *controller = [[MFMailComposeViewController alloc] init];
            controller.mailComposeDelegate = self;
            [controller.navigationBar setBackgroundImage:[UIImage imageNamed:@"navigation_bg_iPhone.png"] forBarMetrics:UIBarMetricsDefault];
            controller.navigationBar.tintColor = [UIColor colorWithRed:51.0/255.0 green:51.0/255.0 blue:51.0/255.0 alpha:1.0];
            [controller setSubject:@""];
            [controller setMessageBody:@" " isHTML:YES];
            [controller setToRecipients:[NSArray arrayWithObjects:@"",nil]];
            UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
            UIImage *ui = resultimg.image;
            pasteboard.image = ui;
            NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(ui)];
            [controller addAttachmentData:imageData mimeType:@"image/png" fileName:@" "];
            [self presentViewController:controller animated:YES completion:NULL];
        }
        else{
            UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"alrt" message:nil delegate:self cancelButtonTitle:@"ok" otherButtonTitles: nil] ;
            [alert show];
        }

    }
    -(void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error
    {

        [MailAlert show];
        switch (result)
        {
            case MFMailComposeResultCancelled:
                MailAlert.message = @"Email Cancelled";
                break;
            case MFMailComposeResultSaved:
                MailAlert.message = @"Email Saved";
                break;
            case MFMailComposeResultSent:
                MailAlert.message = @"Email Sent";
                break;
            case MFMailComposeResultFailed:
                MailAlert.message = @"Email Failed";
                break;
            default:
                MailAlert.message = @"Email Not Sent";
                break;
        }
        [self dismissViewControllerAnimated:YES completion:NULL];
        [MailAlert show];
    }

How to truncate float values?

def trunc(f,n):
  return ('%.16f' % f)[:(n-16)]

Difference between Git and GitHub

Git — The version control tool that GitHub is built on top of.

GitHub — Our company and the name of our software. We build software and websites to help you interact with Git repositories in a nice way.

GitHub.com — The website you log into to view repositories online.

GitHub Desktop — An application that you can install on your computer to help you synchronize local code with GitHub.com.

source: https://guides.github.com/introduction/getting-your-project-on-github/

MVC - Set selected value of SelectList

The below code solves two problems: 1) dynamically set the selected value of the dropdownlist and 2) more importantly to create a dropdownlistfor for an indexed array in the model. the problem here is that everyone uses one instance of the selectlist which is the ViewBoag.List, while the array needs one Selectlist instance for each dropdownlistfor to be able to set the selected value.

create the ViewBag variable as List (not SelectList) int he controller

//controller code
ViewBag.Role = db.LUT_Role.ToList();

//in the view @Html.DropDownListFor(m => m.Contacts[i].Role, new SelectList(ViewBag.Role,"ID","Role",Model.Contacts[i].Role))

Javascript Iframe innerHTML

document.getElementById('iframe01').outerHTML

Best Way to View Generated Source of Webpage?

I was able to solve a similar issue by logging the results of the ajax call to the console. This was the html returned and I could easily see any issues that it had.

in my .done() function of my ajax call I added console.log(results) so I could see the html in the debugger console.

_x000D_
_x000D_
function GetReversals() {_x000D_
    $("#getReversalsLoadingButton").removeClass("d-none");_x000D_
    $("#getReversalsButton").addClass("d-none");_x000D_
_x000D_
    $.ajax({_x000D_
        url: '/Home/LookupReversals',_x000D_
        data: $("#LookupReversals").serialize(),_x000D_
        type: 'Post',_x000D_
        cache: false_x000D_
    }).done(function (result) {_x000D_
        $('#reversalResults').html(result);_x000D_
        console.log(result);_x000D_
    }).fail(function (jqXHR, textStatus, errorThrown) {_x000D_
        //alert("There was a problem getting results.  Please try again. " + jqXHR.responseText + " | " + jqXHR.statusText);_x000D_
        $("#reversalResults").html("<div class='text-danger'>" + jqXHR.responseText + "</div>");_x000D_
    }).always(function () {_x000D_
        $("#getReversalsLoadingButton").addClass("d-none");_x000D_
        $("#getReversalsButton").removeClass("d-none");_x000D_
    });_x000D_
}
_x000D_
_x000D_
_x000D_

CSS: Center block, but align contents to the left

THIS works

<div style="display:inline-block;margin:10px auto;">
    <ul style="list-style-type:none;">
        <li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>root keyword text box</em>.</li>
        <li style="text-align:left;"><span class="red">?</span> YouTube.com website <em>video search text box</em>.</li>
        <li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>scraped keywords listbox</em>.</li>
        <li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>right click context menu</em>.</li>
    </ul>
</div>

How can I listen to the form submit event in javascript?

This is the simplest way you can have your own javascript function be called when an onSubmit occurs.

HTML

<form>
    <input type="text" name="name">
    <input type="submit" name="submit">
</form>

JavaScript

window.onload = function() {
    var form = document.querySelector("form");
    form.onsubmit = submitted.bind(form);
}

function submitted(event) {
    event.preventDefault();
}

How to use sed to replace only the first occurrence in a file?

The following command removes the first occurrence of a string, within a file. It removes the empty line too. It is presented on an xml file, but it would work with any file.

Useful if you work with xml files and you want to remove a tag. In this example it removes the first occurrence of the "isTag" tag.

Command:

sed -e 0,/'<isTag>false<\/isTag>'/{s/'<isTag>false<\/isTag>'//}  -e 's/ *$//' -e  '/^$/d'  source.txt > output.txt

Source file (source.txt)

<xml>
    <testdata>
        <canUseUpdate>true</canUseUpdate>
        <isTag>false</isTag>
        <moduleLocations>
            <module>esa_jee6</module>
            <isTag>false</isTag>
        </moduleLocations>
        <node>
            <isTag>false</isTag>
        </node>
    </testdata>
</xml>

Result file (output.txt)

<xml>
    <testdata>
        <canUseUpdate>true</canUseUpdate>
        <moduleLocations>
            <module>esa_jee6</module>
            <isTag>false</isTag>
        </moduleLocations>
        <node>
            <isTag>false</isTag>
        </node>
    </testdata>
</xml>

ps: it didn't work for me on Solaris SunOS 5.10 (quite old), but it works on Linux 2.6, sed version 4.1.5

Simple UDP example to send and receive data from same socket

here is my soln to define the remote and local port and then write out to a file the received data, put this all in a class of your choice with the correct imports

    static UdpClient sendClient = new UdpClient();
    static int localPort = 49999;
    static int remotePort = 49000;
    static IPEndPoint localEP = new IPEndPoint(IPAddress.Any, localPort);
    static IPEndPoint remoteEP = new IPEndPoint(IPAddress.Parse("127.0.0.1"), remotePort);
    static string logPath = System.AppDomain.CurrentDomain.BaseDirectory + "/recvd.txt";
    static System.IO.StreamWriter fw = new System.IO.StreamWriter(logPath, true);


    private static void initStuff()
    {
      
        fw.AutoFlush = true;
        sendClient.ExclusiveAddressUse = false;
        sendClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        sendClient.Client.Bind(localEP);
        sendClient.BeginReceive(DataReceived, sendClient);
    }

    private static void DataReceived(IAsyncResult ar)
    {
        UdpClient c = (UdpClient)ar.AsyncState;
        IPEndPoint receivedIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
        Byte[] receivedBytes = c.EndReceive(ar, ref receivedIpEndPoint);
        fw.WriteLine(DateTime.Now.ToString("HH:mm:ss.ff tt") +  " (" + receivedBytes.Length + " bytes)");

        c.BeginReceive(DataReceived, ar.AsyncState);
    }


    static void Main(string[] args)
    {
        initStuff();
        byte[] emptyByte = {};
        sendClient.Send(emptyByte, emptyByte.Length, remoteEP);
    }

What is the cause for "angular is not defined"

I had the same problem as deke. I forgot to include the most important script: angular.js :)

<script type="text/javascript" src="bower_components/angular/angular.min.js"></script>

How to make the tab character 4 spaces instead of 8 spaces in nano?

For anyone who may stumble across this old question ...

There is one thing that I think needs to be addressed.

~/.nanorc is used to apply your user specific settings to nano, so if you are editing files that require the use of sudo nano for permissions then this is not going to work.

When using sudo your custom user configuration files will not be loaded when opening a program, as you are not running the program from your account so none of your configuration changes in ~/.nanorc will be applied.

If this is the situation you find yourself in (wanting to run sudo nano and use your own config settings) then you have three options :

  • using command line flags when running sudo nano
  • editing the /root/.nanorc file
  • editing the /etc/nanorc global config file

Keep in mind that /etc/nanorc is a global configuration file and as such it affects all users, which may or may not be a problem depending on whether you have a multi-user system.

Also, user config files will override the global one, so if you were to edit /etc/nanorc and ~/.nanorc with different settings, when you run nano it will load the settings from ~/.nanorc but if you run sudo nano then it will load the settings from /etc/nanorc.

Same goes for /root/.nanorc this will override /etc/nanorc when running sudo nano

Using flags is probably the best option unless you have a lot of options.

how to convert .java file to a .class file

Use the javac program that comes with the JDK (visit java.sun.com if you don't have it). The installer does not automatically add javac to your system path, so you'll need to add the bin directory of the installed path to your system path before you can use it easily.

How to force IE to reload javascript?

To eliminate the need to repeatedly press F5 in an IE tab while developing a website, use ReloadIt.

enter image description here

For each webpage displayed in IE, you can configure a filename, a directory, or a set of them. If any change occurs in any of those configured paths, ReloadIt refreshes the IE tab. A simple tool. It just works.

This will reload everything, not just javascript.

Clearing UIWebview cache

You can disable the caching by doing the following:

NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
[NSURLCache setSharedURLCache:sharedCache];
[sharedCache release];

ARC:

NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
[NSURLCache setSharedURLCache:sharedCache];

How to read single Excel cell value

Here's a solution that may work better in the case you are referencing objWorksheet.UsedRange.

Excel.Worksheet mySheet = ...(load a workbook, etc);
Excel.Range myRange = mySheet.UsedRange;
var values = (myRange.Value as Object[,]);
int rowNumber = 3, columnNumber = 5;
string cellValue = Convert.ToString(values[rowNumber, columnNumber]);

How to run a makefile in Windows?

Here is my quick and temporary way to run a Makefile

  • download make from SourceForge: gnuwin32
  • install it
  • go to the install folder

C:\Program Files (x86)\GnuWin32\bin

  • copy the all files in the bin to the folder that contains Makefile

libiconv2.dll libintl3.dll make.exe

  • open the cmd (you can do it with right click with shift) in the folder that contains Makefile and run

make.exe

done.

Plus, you can add arguments after the command, such as

make.exe skel

Pandas column of lists, create a row for each list element

lst_col = 'samples'

r = pd.DataFrame({
      col:np.repeat(df[col].values, df[lst_col].str.len())
      for col in df.columns.drop(lst_col)}
    ).assign(**{lst_col:np.concatenate(df[lst_col].values)})[df.columns]

Result:

In [103]: r
Out[103]:
    samples  subject  trial_num
0      0.10        1          1
1     -0.20        1          1
2      0.05        1          1
3      0.25        1          2
4      1.32        1          2
5     -0.17        1          2
6      0.64        1          3
7     -0.22        1          3
8     -0.71        1          3
9     -0.03        2          1
10    -0.65        2          1
11     0.76        2          1
12     1.77        2          2
13     0.89        2          2
14     0.65        2          2
15    -0.98        2          3
16     0.65        2          3
17    -0.30        2          3

PS here you may find a bit more generic solution


UPDATE: some explanations: IMO the easiest way to understand this code is to try to execute it step-by-step:

in the following line we are repeating values in one column N times where N - is the length of the corresponding list:

In [10]: np.repeat(df['trial_num'].values, df[lst_col].str.len())
Out[10]: array([1, 1, 1, 2, 2, 2, 3, 3, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3], dtype=int64)

this can be generalized for all columns, containing scalar values:

In [11]: pd.DataFrame({
    ...:           col:np.repeat(df[col].values, df[lst_col].str.len())
    ...:           for col in df.columns.drop(lst_col)}
    ...:         )
Out[11]:
    trial_num  subject
0           1        1
1           1        1
2           1        1
3           2        1
4           2        1
5           2        1
6           3        1
..        ...      ...
11          1        2
12          2        2
13          2        2
14          2        2
15          3        2
16          3        2
17          3        2

[18 rows x 2 columns]

using np.concatenate() we can flatten all values in the list column (samples) and get a 1D vector:

In [12]: np.concatenate(df[lst_col].values)
Out[12]: array([-1.04, -0.58, -1.32,  0.82, -0.59, -0.34,  0.25,  2.09,  0.12,  0.83, -0.88,  0.68,  0.55, -0.56,  0.65, -0.04,  0.36, -0.31])

putting all this together:

In [13]: pd.DataFrame({
    ...:           col:np.repeat(df[col].values, df[lst_col].str.len())
    ...:           for col in df.columns.drop(lst_col)}
    ...:         ).assign(**{lst_col:np.concatenate(df[lst_col].values)})
Out[13]:
    trial_num  subject  samples
0           1        1    -1.04
1           1        1    -0.58
2           1        1    -1.32
3           2        1     0.82
4           2        1    -0.59
5           2        1    -0.34
6           3        1     0.25
..        ...      ...      ...
11          1        2     0.68
12          2        2     0.55
13          2        2    -0.56
14          2        2     0.65
15          3        2    -0.04
16          3        2     0.36
17          3        2    -0.31

[18 rows x 3 columns]

using pd.DataFrame()[df.columns] will guarantee that we are selecting columns in the original order...

Argparse optional positional arguments?

As an extension to @VinaySajip answer. There are additional nargs worth mentioning.

  1. parser.add_argument('dir', nargs=1, default=os.getcwd())

N (an integer). N arguments from the command line will be gathered together into a list

  1. parser.add_argument('dir', nargs='*', default=os.getcwd())

'*'. All command-line arguments present are gathered into a list. Note that it generally doesn't make much sense to have more than one positional argument with nargs='*', but multiple optional arguments with nargs='*' is possible.

  1. parser.add_argument('dir', nargs='+', default=os.getcwd())

'+'. Just like '*', all command-line args present are gathered into a list. Additionally, an error message will be generated if there wasn’t at least one command-line argument present.

  1. parser.add_argument('dir', nargs=argparse.REMAINDER, default=os.getcwd())

argparse.REMAINDER. All the remaining command-line arguments are gathered into a list. This is commonly useful for command line utilities that dispatch to other command line utilities

If the nargs keyword argument is not provided, the number of arguments consumed is determined by the action. Generally this means a single command-line argument will be consumed and a single item (not a list) will be produced.

Edit (copied from a comment by @Acumenus) nargs='?' The docs say: '?'. One argument will be consumed from the command line if possible and produced as a single item. If no command-line argument is present, the value from default will be produced.

Regular expression to match a dot

In javascript you have to use \. to match a dot.

Example

"blah.tests.zibri.org".match('test\\..*')
null

and

"blah.test.zibri.org".match('test\\..*')
["test.zibri.org", index: 5, input: "blah.test.zibri.org", groups: undefined]

How to get a value inside an ArrayList java

You should name your list cars instead of car, so that its name matches its content.

Then you can simply say cars.get(0).getPrice(). And if your Car class doesn't have this method yet, you need to create it.

Redirect using AngularJS

With an example of the not-working code, it will be easy to answer this question, but with this information the best that I can think is that you are calling the $location.path outside of the AngularJS digest.

Try doing this on the directive scope.$apply(function() { $location.path("/route"); });

Abstract class in Java

A class that is declared using the abstract keyword is known as abstract class. Abstraction is a process of hiding the data implementation details, and showing only functionality to the user. Abstraction lets you focus on what the object does instead of how it does it.

Main things of abstract class

  • An abstract class may or may not contain abstract methods.There can be non abstract methods.

    An abstract method is a method that is declared without an implementation (without braces, and followed by a semicolon), like this:

    ex : abstract void moveTo(double deltaX, double deltaY);

  • If a class has at least one abstract method then that class must be abstract

  • Abstract classes may not be instantiated (You are not allowed to create object of Abstract class)

  • To use an abstract class, you have to inherit it from another class. Provide implementations to all the abstract methods in it.

  • If you inherit an abstract class, you have to provide implementations to all the abstract methods in it.

Declare abstract class Specifying abstract keyword before the class during declaration makes it abstract. Have a look at the code below:

abstract class AbstractDemo{ }

Declare abstract method Specifying abstract keyword before the method during declaration makes it abstract. Have a look at the code below,

abstract void moveTo();//no body

Why we need to abstract classes

In an object-oriented drawing application, you can draw circles, rectangles, lines, Bezier curves, and many other graphic objects. These objects all have certain states (for ex -: position, orientation, line color, fill color) and behaviors (for ex -: moveTo, rotate, resize, draw) in common. Some of these states and behaviors are the same for all graphic objects (for ex : fill color, position, and moveTo). Others require different implementation(for ex: resize or draw). All graphic objects must be able to draw or resize themselves, they just differ in how they do it.

This is a perfect situation for an abstract superclass. You can take advantage of the similarities, and declare all the graphic objects to inherit from the same abstract parent object (for ex : GraphicObject) as shown in the following figure. enter image description here

First, you declare an abstract class, GraphicObject, to provide member variables and methods that are wholly shared by all subclasses, such as the current position and the moveTo method. GraphicObject also declared abstract methods, such as draw or resize, that need to be a implemented by all subclasses but must be implemented in different ways. The GraphicObject class can look something like this:

abstract class GraphicObject {

  void moveTo(int x, int y) {
    // Inside this method we have to change the position of the graphic 
    // object according to x,y     
    // This is the same in every GraphicObject. Then we can implement here. 
  }

  abstract void draw(); // But every GraphicObject drawing case is 
                        // unique, not common. Then we have to create that 
                        // case inside each class. Then create these    
                        // methods as abstract 
  abstract void resize();
}

Usage of abstract method in sub classes Each non abstract subclasses of GraphicObject, such as Circle and Rectangle, must provide implementations for the draw and resize methods.

class Circle extends GraphicObject {
  void draw() {
    //Add to some implementation here
  }
  void resize() {
    //Add to some implementation here   
  }
}
class Rectangle extends GraphicObject {
  void draw() {
    //Add to some implementation here
  }
  void resize() {
    //Add to some implementation here
  }
}

Inside the main method you can call all methods like this:

public static void main(String args[]){
   GraphicObject c = new Circle();
   c.draw();
   c.resize();
   c.moveTo(4,5);   
}

Ways to achieve abstraction in Java

There are two ways to achieve abstraction in java

  • Abstract class (0 to 100%)
  • Interface (100%)

Abstract class with constructors, data members, methods, etc

abstract class GraphicObject {

  GraphicObject (){
    System.out.println("GraphicObject  is created");
  }
  void moveTo(int y, int x) {
       System.out.println("Change position according to "+ x+ " and " + y);
  }
  abstract void draw();
}

class Circle extends GraphicObject {
  void draw() {
    System.out.println("Draw the Circle");
  }
}

class TestAbstract {  
 public static void main(String args[]){

   GraphicObject  grObj = new Circle ();
   grObj.draw();
   grObj.moveTo(4,6);
 }
}

Output:

GraphicObject  is created
Draw the Circle
Change position according to 6 and 4

Remember two rules:

  • If the class has few abstract methods and few concrete methods, declare it as an abstract class.

  • If the class has only abstract methods, declare it as an interface.

References:

Use a list of values to select rows from a pandas dataframe

You can use isin method:

In [1]: df = pd.DataFrame({'A': [5,6,3,4], 'B': [1,2,3,5]})

In [2]: df
Out[2]:
   A  B
0  5  1
1  6  2
2  3  3
3  4  5

In [3]: df[df['A'].isin([3, 6])]
Out[3]:
   A  B
1  6  2
2  3  3

And to get the opposite use ~:

In [4]: df[~df['A'].isin([3, 6])]
Out[4]:
   A  B
0  5  1
3  4  5

Convert a character digit to the corresponding integer in C

If your digit is, say, '5', in ASCII it is represented as the binary number 0011 0101 (53). Every digit has the highest four bits 0011 and the lowest 4 bits represent the digit in bcd. So you just do

char cdig = '5';
int dig = cdig & 0xf; // dig contains the number 5

to get the lowest 4 bits, or, what its same, the digit. In asm, it uses and operation instead of sub(as in the other answers).

Java logical operator short-circuiting

In plain terms, short-circuiting means stopping evaluation once you know that the answer can no longer change. For example, if you are evaluating a chain of logical ANDs and you discover a FALSE in the middle of that chain, you know the result is going to be false, no matter what are the values of the rest of the expressions in the chain. Same goes for a chain of ORs: once you discover a TRUE, you know the answer right away, and so you can skip evaluating the rest of the expressions.

You indicate to Java that you want short-circuiting by using && instead of & and || instead of |. The first set in your post is short-circuiting.

Note that this is more than an attempt at saving a few CPU cycles: in expressions like this

if (mystring != null && mystring.indexOf('+') > 0) {
    ...
}

short-circuiting means a difference between correct operation and a crash (in the case where mystring is null).

Maven: mvn command not found

I tried solutions from other threads. Adding M2 and M2_HOME at System variables, and even at User variables. Running cmd as admin. None of the methods worked.

But today I added entire path to maven bin to my System variables "PATH" (C:\Program Files (x86)\Apache Software Foundation\apache-maven-3.1.0\bin) besides other paths, and so far it's working good. Hopefully it'll stay that way.

What's the best practice for putting multiple projects in a git repository?

While most people will tell you to just use multiple repositories, I feel it's worth mentioning there are other solutions.

Solution 1

A single repository can contain multiple independent branches, called orphan branches. Orphan branches are completely separate from each other; they do not share histories.

git checkout --orphan BRANCHNAME

This creates a new branch, unrelated to your current branch. Each project should be in its own orphaned branch.

Now for whatever reason, git needs a bit of cleanup after an orphan checkout.

rm .git/index
rm -r *

Make sure everything is committed before deleting

Once the orphan branch is clean, you can use it normally.

Solution 2

Avoid all the hassle of orphan branches. Create two independent repositories, and push them to the same remote. Just use different branch names for each repo.

# repo 1
git push origin master:master-1

# repo 2
git push origin master:master-2

Get class labels from Keras functional model

You must use the labels index you have, here what I do for text classification:

# data labels = [1, 2, 1...]
labels_index = { "website" : 0, "money" : 1 ....} 
# to feed model
label_categories = to_categorical(np.asarray(labels)) 

Then, for predictions:

texts = ["hello, rejoins moi sur skype", "bonjour comment ça va ?", "tu me donnes de l'argent"]

sequences = tokenizer.texts_to_sequences(texts)

data = pad_sequences(sequences, maxlen=MAX_SEQUENCE_LENGTH)

predictions = model.predict(data)

t = 0

for text in texts:
    i = 0
    print("Prediction for \"%s\": " % (text))
    for label in labels_index:
        print("\t%s ==> %f" % (label, predictions[t][i]))
        i = i + 1
    t = t + 1

This gives:

Prediction for "hello, rejoins moi sur skype": 
    website ==> 0.759483
    money ==> 0.037091
    under ==> 0.010587
    camsite ==> 0.114436
    email ==> 0.075975
    abuse ==> 0.002428
Prediction for "bonjour comment ça va ?": 
    website ==> 0.433079
    money ==> 0.084878
    under ==> 0.048375
    camsite ==> 0.036674
    email ==> 0.369197
    abuse ==> 0.027798
Prediction for "tu me donnes de l'argent": 
    website ==> 0.006223
    money ==> 0.095308
    under ==> 0.003586
    camsite ==> 0.003115
    email ==> 0.884112
    abuse ==> 0.007655

Excel VBA Macro: User Defined Type Not Defined

I am late for the party. Try replacing as below, mine worked perfectly- "DOMDocument" to "MSXML2.DOMDocument60" "XMLHTTP" to "MSXML2.XMLHTTP60"

IF Statement multiple conditions, same statement

if (checkbox.checked && columnname != a && columnname != b && columnname != c)
    {
      "statement 1"
    }
else if (columnname != a && columnname != b && columnname != c 
        && columnname != A2)
    {
      "statement 1"
    }

is one way to simplify a little.

IN vs OR in the SQL WHERE Clause

The best way to find out is looking at the Execution Plan.


I tried it with Oracle, and it was exactly the same.

CREATE TABLE performance_test AS ( SELECT * FROM dba_objects );

SELECT * FROM performance_test
WHERE object_name IN ('DBMS_STANDARD', 'DBMS_REGISTRY', 'DBMS_LOB' );

Even though the query uses IN, the Execution Plan says that it uses OR:

--------------------------------------------------------------------------------------    
| Id  | Operation         | Name             | Rows  | Bytes | Cost (%CPU)| Time     |    
--------------------------------------------------------------------------------------    
|   0 | SELECT STATEMENT  |                  |     8 |  1416 |   163   (2)| 00:00:02 |    
|*  1 |  TABLE ACCESS FULL| PERFORMANCE_TEST |     8 |  1416 |   163   (2)| 00:00:02 |    
--------------------------------------------------------------------------------------    

Predicate Information (identified by operation id):                                       
---------------------------------------------------                                       

   1 - filter("OBJECT_NAME"='DBMS_LOB' OR "OBJECT_NAME"='DBMS_REGISTRY' OR                
              "OBJECT_NAME"='DBMS_STANDARD')                                              

How do I calculate square root in Python?

You have to write: sqrt = x**(1/2.0), otherwise an integer division is performed and the expression 1/2 returns 0.

This behavior is "normal" in Python 2.x, whereas in Python 3.x 1/2 evaluates to 0.5. If you want your Python 2.x code to behave like 3.x w.r.t. division write from __future__ import division - then 1/2 will evaluate to 0.5 and for backwards compatibility, 1//2 will evaluate to 0.

And for the record, the preferred way to calculate a square root is this:

import math
math.sqrt(x)

How to select a CRAN mirror in R

I use the ~/.Rprofile solution suggested by Dirk, but I just wanted to point out that

chooseCRANmirror(graphics=FALSE)

seems to be the sensible thing to do instead of

chooseCRANmirror(81)

, which may work, but which involves the magic number 81 (or maybe this is subtle way to promote tourism to 81 = UK (Bristol) :-) )

How to detect READ_COMMITTED_SNAPSHOT is enabled?

SELECT is_read_committed_snapshot_on FROM sys.databases 
WHERE name= 'YourDatabase'

Return value:

  • 1: READ_COMMITTED_SNAPSHOT option is ON. Read operations under the READ COMMITTED isolation level are based on snapshot scans and do not acquire locks.
  • 0 (default): READ_COMMITTED_SNAPSHOT option is OFF. Read operations under the READ COMMITTED isolation level use Shared (S) locks.