Programs & Examples On #Qt vs addin

Slide up/down effect with ng-show and ng-animate

This class-based javascript animation works in AngularJS 1.2 (and 1.4 tested)

Edit: I ended up abandoning this code and went a completely different direction. I like my other answer much better. This answer will give you some problems in certain situations.

myApp.animation('.ng-show-toggle-slidedown', function(){
  return {
    beforeAddClass : function(element, className, done){
        if (className == 'ng-hide'){
            $(element).slideUp({duration: 400}, done);
        } else {done();}
    },
    beforeRemoveClass :  function(element, className, done){
        if (className == 'ng-hide'){
            $(element).css({display:'none'});
            $(element).slideDown({duration: 400}, done);
        } else {done();}
    }
}

});

Simply add the .ng-hide-toggle-slidedown class to the container element, and the jQuery slide down behavior will be implemented based on the ng-hide class.

You must include the $(element).css({display:'none'}) line in the beforeRemoveClass method because jQuery will not execute a slideDown unless the element is in a state of display: none prior to starting the jQuery animation. AngularJS uses the CSS

.ng-hide:not(.ng-hide-animate) {
    display: none !important;
}

to hide the element. jQuery is not aware of this state, and jQuery will need the display:none prior to the first slide down animation.

The AngularJS animation will add the .ng-hide-animate and .ng-animate classes while the animation is occuring.

Find and replace with a newline in Visual Studio Code

In version 1.1.1:

  • Ctrl+H
  • Check the regular exp icon .*
  • Search: ><
  • Replace: >\n<

How can I replace text with CSS?

Unlike what I see in every single other answer, you don't need to use pseudo elements in order to replace the content of a tag with an image

<div class="pvw-title">Facts</div>

    div.pvw-title { /* No :after or :before required */
        content: url("your URL here");
    }

What is a good pattern for using a Global Mutex in C#?

Using the accepted answer I create a helper class so you could use it in a similar way you would use the Lock statement. Just thought I'd share.

Use:

using (new SingleGlobalInstance(1000)) //1000ms timeout on global lock
{
    //Only 1 of these runs at a time
    RunSomeStuff();
}

And the helper class:

class SingleGlobalInstance : IDisposable
{
    //edit by user "jitbit" - renamed private fields to "_"
    public bool _hasHandle = false;
    Mutex _mutex;

    private void InitMutex()
    {
        string appGuid = ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value;
        string mutexId = string.Format("Global\\{{{0}}}", appGuid);
        _mutex = new Mutex(false, mutexId);

        var allowEveryoneRule = new MutexAccessRule(new SecurityIdentifier(WellKnownSidType.WorldSid, null), MutexRights.FullControl, AccessControlType.Allow);
        var securitySettings = new MutexSecurity();
        securitySettings.AddAccessRule(allowEveryoneRule);
        _mutex.SetAccessControl(securitySettings);
    }

    public SingleGlobalInstance(int timeOut)
    {
        InitMutex();
        try
        {
            if(timeOut < 0)
                _hasHandle = _mutex.WaitOne(Timeout.Infinite, false);
            else
                _hasHandle = _mutex.WaitOne(timeOut, false);

            if (_hasHandle == false)
                throw new TimeoutException("Timeout waiting for exclusive access on SingleInstance");
        }
        catch (AbandonedMutexException)
        {
            _hasHandle = true;
        }
    }


    public void Dispose()
    {
        if (_mutex != null)
        {
            if (_hasHandle)
                _mutex.ReleaseMutex();
            _mutex.Close();
        }
    }
}

How do you debug MySQL stored procedures?

MySql Connector/NET also includes a stored procedure debugger integrated in visual studio as of version 6.6, You can get the installer and the source here: http://dev.mysql.com/downloads/connector/net/

Some documentation / screenshots: https://dev.mysql.com/doc/visual-studio/en/visual-studio-debugger.html

You can follow the annoucements here: http://forums.mysql.com/read.php?38,561817,561817#msg-561817

UPDATE: The MySql for Visual Studio was split from Connector/NET into a separate product, you can pick it (including the debugger) from here https://dev.mysql.com/downloads/windows/visualstudio/1.2.html (still free & open source).

DISCLAIMER: I was the developer who authored the Stored procedures debugger engine for MySQL for Visual Studio product.

Rails 3 check if attribute changed

For rails 5.1+ callbacks

As of Ruby on Rails 5.1, the attribute_changed? and attribute_was ActiveRecord methods will be deprecated

Use saved_change_to_attribute? instead of attribute_changed?

@user.saved_change_to_street1? # => true/false

More examples here

PHP Convert String into Float/Double

If the function floatval does not work you can try to make this :

    $string = "2968789218";
    $float = $string * 1.0;
    echo $float;

But for me all the previous answer worked ( try it in http://writecodeonline.com/php/ ) Maybe the problem is on your server ?

Using LINQ to remove elements from a List<T>

Below is the example to remove the element from the list.

 List<int> items = new List<int>() { 2, 2, 3, 4, 2, 7, 3,3,3};

 var result = items.Remove(2);//Remove the first ocurence of matched elements and returns boolean value
 var result1 = items.RemoveAll(lst => lst == 3);// Remove all the matched elements and returns count of removed element
 items.RemoveAt(3);//Removes the elements at the specified index

How do I add a project as a dependency of another project?

Assuming the MyEjbProject is not another Maven Project you own or want to build with maven, you could use system dependencies to link to the existing jar file of the project like so

<project>
   ...
   <dependencies>
      <dependency>
         <groupId>yourgroup</groupId>
         <artifactId>myejbproject</artifactId>
         <version>2.0</version>
         <scope>system</scope>
         <systemPath>path/to/myejbproject.jar</systemPath>
      </dependency>
   </dependencies>
   ...
</project>

That said it is usually the better (and preferred way) to install the package to the repository either by making it a maven project and building it or installing it the way you already seem to do.


If they are, however, dependent on each other, you can always create a separate parent project (has to be a "pom" project) declaring the two other projects as its "modules". (The child projects would not have to declare the third project as their parent). As a consequence you'd get a new directory for the new parent project, where you'd also quite probably put the two independent projects like this:

parent
|- pom.xml
|- MyEJBProject
|   `- pom.xml
`- MyWarProject
    `- pom.xml

The parent project would get a "modules" section to name all the child modules. The aggregator would then use the dependencies in the child modules to actually find out the order in which the projects are to be built)

<project>
   ...
   <artifactId>myparentproject</artifactId>
   <groupId>...</groupId>
   <version>...</version>

   <packaging>pom</packaging>
   ...
   <modules>
     <module>MyEJBModule</module>
     <module>MyWarModule</module>
   </modules>
   ...
</project>

That way the projects can relate to each other but (once they are installed in the local repository) still be used independently as artifacts in other projects


Finally, if your projects are not in related directories, you might try to give them as relative modules:

filesystem
 |- mywarproject
 |   `pom.xml
 |- myejbproject
 |   `pom.xml
 `- parent
     `pom.xml

now you could just do this (worked in maven 2, just tried it):

<!--parent-->
<project>
  <modules>
    <module>../mywarproject</module>
    <module>../myejbproject</module>
  </modules>
</project>

how do you insert null values into sql server

INSERT INTO atable (x,y,z) VALUES ( NULL,NULL,NULL)

How does lock work exactly?

lock is actually hidden Monitor class.

Adding a stylesheet to asp.net (using Visual Studio 2010)

Several things here.

First off, you're defining your CSS in 3 places!

In line, in the head and externally. I suggest you only choose one. I'm going to suggest externally.

I suggest you update your code in your ASP form from

<td style="background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;" 
        class="style6">

to this:

<td  class="style6">

And then update your css too

.style6
    {
        height: 79px; background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;
    }

This removes the inline.

Now, to move it from the head of the webForm.

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>AR Toolbox</title>
    <link rel="Stylesheet" href="css/master.css" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<table class="style1">
    <tr>
        <td class="style6">
            <asp:Menu ID="Menu1" runat="server">
                <Items>
                    <asp:MenuItem Text="Home" Value="Home"></asp:MenuItem>
                    <asp:MenuItem Text="About" Value="About"></asp:MenuItem>
                    <asp:MenuItem Text="Compliance" Value="Compliance">
                        <asp:MenuItem Text="Item 1" Value="Item 1"></asp:MenuItem>
                        <asp:MenuItem Text="Item 2" Value="Item 2"></asp:MenuItem>
                    </asp:MenuItem>
                    <asp:MenuItem Text="Tools" Value="Tools"></asp:MenuItem>
                    <asp:MenuItem Text="Contact" Value="Contact"></asp:MenuItem>
                </Items>
            </asp:Menu>
        </td>
    </tr>
    <tr>
        <td class="style6">
            <img alt="South University'" class="style7" 
                src="file:///C:/Users/jnewnam/Documents/Visual%20Studio%202010/WebSites/WebSite1/img/suo_n_seal_hor_pantone.png" /></td>
    </tr>
    <tr>
        <td class="style2">
            <table class="style3">
                <tr>
                    <td>
                        &nbsp;</td>
                </tr>
            </table>
        </td>
    </tr>
    <tr>
        <td style="color: #FFFFFF; background-color: #A3A3A3">
            This is the footer.</td>
    </tr>
</table>
</form>
</body>
</html>

Now, in a new file called master.css (in your css folder) add

ul {
list-style-type:none;
margin:0;
padding:0;
}

li {
display:inline;
padding:20px;
}
.style1
{
    width: 100%;
}
.style2
{
    height: 459px;
}
.style3
{
    width: 100%;
    height: 100%;
}
.style6
{
    height: 79px; background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;
}
.style7
{
    width: 345px;
    height: 73px;
}

MongoDB: How to find the exact version of installed MongoDB

Sometimes you need to see version of mongodb after making a connection from your project/application/code. In this case you can follow like this:

 mongoose.connect(
    encodeURI(DB_URL), {
      keepAlive: true
    },
    (err) => {
      if (err) {
        console.log(err)
      }else{
           const con = new mongoose.mongo.Admin(mongoose.connection.db)
              con.buildInfo( (err, db) => {
              if(err){
                throw err
              }
             // see the db version
             console.log(db.version)
            })
      }
    }
  )

Hope this will be helpful for someone.

How an 'if (A && B)' statement is evaluated?

Yes, it is called Short-circuit Evaluation.

If the validity of the boolean statement can be assured after part of the statement, the rest is not evaluated.

This is very important when some of the statements have side-effects.

Parsing xml using powershell

[xml]$xmlfile = '<xml> <Section name="BackendStatus"> <BEName BE="crust" Status="1" /> <BEName BE="pizza" Status="1" /> <BEName BE="pie" Status="1" /> <BEName BE="bread" Status="1" /> <BEName BE="Kulcha" Status="1" /> <BEName BE="kulfi" Status="1" /> <BEName BE="cheese" Status="1" /> </Section> </xml>'

foreach ($bename in $xmlfile.xml.Section.BEName) {
    if($bename.Status -eq 1){
        #Do something
    }
}

How to show an alert box in PHP?

echo "<script>alert('same message');</script>";

This may help.

Vue.js : How to set a unique ID for each component instance?

If you're using TypeScript, without any plugin, you could simply add a static id in your class component and increment it in the created() method. Each component will have a unique id (add a string prefix to avoid collision with another components which use the same tip)

<template>
  <div>
    <label :for="id">Label text for {{id}}</label>
    <input :id="id" type="text" />
  </div>
</template>

<script lang="ts">
  ...
  @Component
  export default class MyComponent extends Vue {
    private id!: string;
    private static componentId = 0;
    ...
    created() {
      MyComponent.componentId += 1;
      this.id = `my-component-${MyComponent.componentId}`;
    }
 </script>

Smart way to truncate long strings

This function do the truncate space and words parts also.(ex: Mother into Moth...)

String.prototype.truc= function (length) {
        return this.length>length ? this.substring(0, length) + '&hellip;' : this;
};

usage:

"this is long length text".trunc(10);
"1234567890".trunc(5);

output:

this is lo...

12345...

Passing functions with arguments to another function in Python?

Use functools.partial, not lambdas! And ofc Perform is a useless function, you can pass around functions directly.

for func in [Action1, partial(Action2, p), partial(Action3, p, r)]:
  func()

How to deselect a selected UITableView cell?

This is a solution for Swift 4

 in tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)

just add

tableView.deselectRow(at: indexPath, animated: true)

it works like a charm

example:

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
//some code
}

Is it possible to display inline images from html in an Android TextView?

If you have a look at the documentation for Html.fromHtml(text) you'll see it says:

Any <img> tags in the HTML will display as a generic replacement image which your program can then go through and replace with real images.

If you don't want to do this replacement yourself you can use the other Html.fromHtml() method which takes an Html.TagHandler and an Html.ImageGetter as arguments as well as the text to parse.

In your case you could parse null as for the Html.TagHandler but you'd need to implement your own Html.ImageGetter as there isn't a default implementation.

However, the problem you're going to have is that the Html.ImageGetter needs to run synchronously and if you're downloading images from the web you'll probably want to do that asynchronously. If you can add any images you want to display as resources in your application the your ImageGetter implementation becomes a lot simpler. You could get away with something like:

private class ImageGetter implements Html.ImageGetter {

    public Drawable getDrawable(String source) {
        int id;

        if (source.equals("stack.jpg")) {
            id = R.drawable.stack;
        }
        else if (source.equals("overflow.jpg")) {
            id = R.drawable.overflow;
        }
        else {
            return null;
        }

        Drawable d = getResources().getDrawable(id);
        d.setBounds(0,0,d.getIntrinsicWidth(),d.getIntrinsicHeight());
        return d;
    }
};

You'd probably want to figure out something smarter for mapping source strings to resource IDs though.

Chrome refuses to execute an AJAX script due to wrong MIME type

I encountered this error using IIS 7.0 with a custom 404 error page, although I suspect this will happen with any 404 page. The server returned an html 404 response with a text/html mime type which could not (rightly) be executed.

CSV file written with Python has blank lines between each row

When using Python 3 the empty lines can be avoid by using the codecs module. As stated in the documentation, files are opened in binary mode so no change of the newline kwarg is necessary. I was running into the same issue recently and that worked for me:

with codecs.open( csv_file,  mode='w', encoding='utf-8') as out_csv:
     csv_out_file = csv.DictWriter(out_csv)

How to include a child object's child object in Entity Framework 5

With EF Core in .NET Core you can use the keyword ThenInclude :

return DatabaseContext.Applications
 .Include(a => a.Children).ThenInclude(c => c.ChildRelationshipType);

Include childs from childrens collection :

return DatabaseContext.Applications
 .Include(a => a.Childrens).ThenInclude(cs => cs.ChildRelationshipType1)
 .Include(a => a.Childrens).ThenInclude(cs => cs.ChildRelationshipType2);

Nginx: Permission denied for nginx on Ubuntu

Permission to view log files is granted to users being in the group adm.

To add a user to this group on the command line issue:

sudo usermod -aG adm <USER>

How do I solve the "server DNS address could not be found" error on Windows 10?

Steps to manually configure DNS:

  1. You can access Network and Sharing center by right clicking on the Network icon on the taskbar.

  2. Now choose adapter settings from the side menu.

  3. This will give you a list of the available network adapters in the system . From them right click on the adapter you are using to connect to the internet now and choose properties option.

  4. In the networking tab choose ‘Internet Protocol Version 4 (TCP/IPv4)’.

  5. Now you can see the properties dialogue box showing the properties of IPV4. Here you need to change some properties.

    Select ‘use the following DNS address’ option. Now fill the following fields as given here.

    Preferred DNS server: 208.67.222.222

    Alternate DNS server : 208.67.220.220

    This is an available Open DNS address. You may also use google DNS server addresses.

    After filling these fields. Check the ‘validate settings upon exit’ option. Now click OK.

You have to add this DNS server address in the router configuration also (by referring the router manual for more information).

Refer : for above method & alternative

If none of this works, then open command prompt(Run as Administrator) and run these:

ipconfig /flushdns
ipconfig /registerdns
ipconfig /release
ipconfig /renew
NETSH winsock reset catalog
NETSH int ipv4 reset reset.log
NETSH int ipv6 reset reset.log
Exit

Hopefully that fixes it, if its still not fixed there is a chance that its a NIC related issue(driver update or h/w).

Also FYI, this has a thread on Microsoft community : Windows 10 - DNS Issue

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

I'll also prefer ALTER LOGIN Command as in accepted answer and described here

But for GUI lover

  1. Go to [SERVER INSTANCE] --> Security --> Logins --> [YOUR LOGIN]
  2. Right Click on [YOUR LOGIN]
  3. Update the Default Database Option at the bottom of the page

Tired of reading!!! just look at following

enter image description here

Programmatically extract contents of InstallShield setup.exe

The free and open-source program called cabextract will list and extract the contents of not just .cab-files, but Macrovision's archives too:

% cabextract /tmp/QLWREL.EXE
Extracting cabinet: /tmp/QLWREL.EXE
  extracting ikernel.dll
  extracting IsProBENT.tlb
  ....
  extracting IScript.dll
  extracting iKernel.rgs

All done, no errors.

Is it possible to iterate through JSONArray?

You can use the opt(int) method and use a classical for loop.

simulate background-size:cover on <video> or <img>

Based on Daniel de Wit's answer and comments, I searched a bit more. Thanks to him for the solution.

The solution is to use object-fit: cover; which has a great support (every modern browser support it). If you really want to support IE, you can use a polyfill like object-fit-images or object-fit.

Demos :

_x000D_
_x000D_
img {_x000D_
  float: left;_x000D_
  width: 100px;_x000D_
  height: 80px;_x000D_
  border: 1px solid black;_x000D_
  margin-right: 1em;_x000D_
}_x000D_
.fill {_x000D_
  object-fit: fill;_x000D_
}_x000D_
.contain {_x000D_
  object-fit: contain;_x000D_
}_x000D_
.cover {_x000D_
  object-fit: cover;_x000D_
}_x000D_
.none {_x000D_
  object-fit: none;_x000D_
}_x000D_
.scale-down {_x000D_
  object-fit: scale-down;_x000D_
}
_x000D_
<img class="fill" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
<img class="contain" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
<img class="cover" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
<img class="none" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
<img class="scale-down" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>
_x000D_
_x000D_
_x000D_

and with a parent:

_x000D_
_x000D_
div {_x000D_
  float: left;_x000D_
  width: 100px;_x000D_
  height: 80px;_x000D_
  border: 1px solid black;_x000D_
  margin-right: 1em;_x000D_
}_x000D_
img {_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
}_x000D_
.fill {_x000D_
  object-fit: fill;_x000D_
}_x000D_
.contain {_x000D_
  object-fit: contain;_x000D_
}_x000D_
.cover {_x000D_
  object-fit: cover;_x000D_
}_x000D_
.none {_x000D_
  object-fit: none;_x000D_
}_x000D_
.scale-down {_x000D_
  object-fit: scale-down;_x000D_
}
_x000D_
<div>_x000D_
<img class="fill" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
</div><div>_x000D_
<img class="contain" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
</div><div>_x000D_
<img class="cover" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
</div><div>_x000D_
<img class="none" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
</div><div>_x000D_
<img class="scale-down" src="http://www.peppercarrot.com/data/wiki/medias/img/chara_carrot.jpg"/>_x000D_
</div>
_x000D_
_x000D_
_x000D_

mysqli::mysqli(): (HY000/2002): Can't connect to local MySQL server through socket 'MySQL' (2)

When you use just "localhost" the MySQL client library tries to use a Unix domain socket for the connection instead of a TCP/IP connection. The error is telling you that the socket, called MySQL, cannot be used to make the connection, probably because it does not exist (error number 2).

From the MySQL Documentation:

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option.

There are a few ways to solve this problem.

  1. You can just use TCP/IP instead of the Unix socket. You would do this by using 127.0.0.1 instead of localhost when you connect. The Unix socket might by faster and safer to use, though.
  2. You can change the socket in php.ini: open the MySQL configuration file my.cnf to find where MySQL creates the socket, and set PHP's mysqli.default_socket to that path. On my system it's /var/run/mysqld/mysqld.sock.
  3. Configure the socket directly in the PHP script when opening the connection. For example:

    $db = new MySQLi('localhost', 'kamil', '***', '', 0, 
                                  '/var/run/mysqld/mysqld.sock')
    

How can I consume a WSDL (SOAP) web service in Python?

I would recommend that you have a look at SUDS

"Suds is a lightweight SOAP python client for consuming Web Services."

How to make a GUI for bash scripts?

Please, take a look at my library: http://sites.google.com/site/easybashgui

It is intended to handle, with the same commands set, indifferently all four big tools "kdialog", "Xdialog", "cdialog" and "zenity", depending if X is running or not, if D.E. is KDE or Gnome or other. There are 15 different functions ( among them there are two called "progress" and "adjust" )...

Bye :-)

Detecting a long press with Android

The solution by MSquare works only if you hold a specific pixel, but that's an unreasonable expectation for an end user unless they use a mouse (which they don't, they use fingers).

So I added a bit of a threshold for the distance between the DOWN and the UP action in case there was a MOVE action inbetween.

final Handler longPressHandler = new Handler();
Runnable longPressedRunnable = new Runnable() {
    public void run() {
        Log.e(TAG, "Long press detected in long press Handler!");
        isLongPressHandlerActivated = true;
    }
};

private boolean isLongPressHandlerActivated = false;

private boolean isActionMoveEventStored = false;
private float lastActionMoveEventBeforeUpX;
private float lastActionMoveEventBeforeUpY;

@Override
public boolean dispatchTouchEvent(MotionEvent event) {
    if(event.getAction() == MotionEvent.ACTION_DOWN) {
        longPressHandler.postDelayed(longPressedRunnable, 1000);
    }
    if(event.getAction() == MotionEvent.ACTION_MOVE || event.getAction() == MotionEvent.ACTION_HOVER_MOVE) {
        if(!isActionMoveEventStored) {
            isActionMoveEventStored = true;
            lastActionMoveEventBeforeUpX = event.getX();
            lastActionMoveEventBeforeUpY = event.getY();
        } else {
            float currentX = event.getX();
            float currentY = event.getY();
            float firstX = lastActionMoveEventBeforeUpX;
            float firstY = lastActionMoveEventBeforeUpY;
            double distance = Math.sqrt(
                    (currentY - firstY) * (currentY - firstY) + ((currentX - firstX) * (currentX - firstX)));
            if(distance > 20) {
                longPressHandler.removeCallbacks(longPressedRunnable);
            }
        }
    }
    if(event.getAction() == MotionEvent.ACTION_UP) {
        isActionMoveEventStored = false;
        longPressHandler.removeCallbacks(longPressedRunnable);
        if(isLongPressHandlerActivated) {
            Log.d(TAG, "Long Press detected; halting propagation of motion event");
            isLongPressHandlerActivated = false;
            return false;
        }
    }
    return super.dispatchTouchEvent(event);
}

How to identify platform/compiler from preprocessor macros?

Here's what I use:

#ifdef _WIN32 // note the underscore: without it, it's not msdn official!
    // Windows (x64 and x86)
#elif __unix__ // all unices, not all compilers
    // Unix
#elif __linux__
    // linux
#elif __APPLE__
    // Mac OS, not sure if this is covered by __posix__ and/or __unix__ though...
#endif

EDIT: Although the above might work for the basics, remember to verify what macro you want to check for by looking at the Boost.Predef reference pages. Or just use Boost.Predef directly.

Oracle - Insert New Row with Auto Incremental ID

To get an auto increment number you need to use a sequence in Oracle. (See here and here).

CREATE SEQUENCE my_seq;

SELECT my_seq.NEXTVAL FROM DUAL; -- to get the next value

-- use in a trigger for your table demo
CREATE OR REPLACE TRIGGER demo_increment 
BEFORE INSERT ON demo
FOR EACH ROW

BEGIN
  SELECT my_seq.NEXTVAL
  INTO   :new.id
  FROM   dual;
END;
/

Getting the closest string match

I was presented with this problem about a year ago when it came to looking up user entered information about a oil rig in a database of miscellaneous information. The goal was to do some sort of fuzzy string search that could identify the database entry with the most common elements.

Part of the research involved implementing the Levenshtein distance algorithm, which determines how many changes must be made to a string or phrase to turn it into another string or phrase.

The implementation I came up with was relatively simple, and involved a weighted comparison of the length of the two phrases, the number of changes between each phrase, and whether each word could be found in the target entry.

The article is on a private site so I'll do my best to append the relevant contents here:


Fuzzy String Matching is the process of performing a human-like estimation of the similarity of two words or phrases. In many cases, it involves identifying words or phrases which are most similar to each other. This article describes an in-house solution to the fuzzy string matching problem and its usefulness in solving a variety of problems which can allow us to automate tasks which previously required tedious user involvement.

Introduction

The need to do fuzzy string matching originally came about while developing the Gulf of Mexico Validator tool. What existed was a database of known gulf of Mexico oil rigs and platforms, and people buying insurance would give us some badly typed out information about their assets and we had to match it to the database of known platforms. When there was very little information given, the best we could do is rely on an underwriter to "recognize" the one they were referring to and call up the proper information. This is where this automated solution comes in handy.

I spent a day researching methods of fuzzy string matching, and eventually stumbled upon the very useful Levenshtein distance algorithm on Wikipedia.

Implementation

After reading about the theory behind it, I implemented and found ways to optimize it. This is how my code looks like in VBA:

'Calculate the Levenshtein Distance between two strings (the number of insertions,
'deletions, and substitutions needed to transform the first string into the second)
Public Function LevenshteinDistance(ByRef S1 As String, ByVal S2 As String) As Long
    Dim L1 As Long, L2 As Long, D() As Long 'Length of input strings and distance matrix
    Dim i As Long, j As Long, cost As Long 'loop counters and cost of substitution for current letter
    Dim cI As Long, cD As Long, cS As Long 'cost of next Insertion, Deletion and Substitution
    L1 = Len(S1): L2 = Len(S2)
    ReDim D(0 To L1, 0 To L2)
    For i = 0 To L1: D(i, 0) = i: Next i
    For j = 0 To L2: D(0, j) = j: Next j

    For j = 1 To L2
        For i = 1 To L1
            cost = Abs(StrComp(Mid$(S1, i, 1), Mid$(S2, j, 1), vbTextCompare))
            cI = D(i - 1, j) + 1
            cD = D(i, j - 1) + 1
            cS = D(i - 1, j - 1) + cost
            If cI <= cD Then 'Insertion or Substitution
                If cI <= cS Then D(i, j) = cI Else D(i, j) = cS
            Else 'Deletion or Substitution
                If cD <= cS Then D(i, j) = cD Else D(i, j) = cS
            End If
        Next i
    Next j
    LevenshteinDistance = D(L1, L2)
End Function

Simple, speedy, and a very useful metric. Using this, I created two separate metrics for evaluating the similarity of two strings. One I call "valuePhrase" and one I call "valueWords". valuePhrase is just the Levenshtein distance between the two phrases, and valueWords splits the string into individual words, based on delimiters such as spaces, dashes, and anything else you'd like, and compares each word to each other word, summing up the shortest Levenshtein distance connecting any two words. Essentially, it measures whether the information in one 'phrase' is really contained in another, just as a word-wise permutation. I spent a few days as a side project coming up with the most efficient way possible of splitting a string based on delimiters.

valueWords, valuePhrase, and Split function:

Public Function valuePhrase#(ByRef S1$, ByRef S2$)
    valuePhrase = LevenshteinDistance(S1, S2)
End Function

Public Function valueWords#(ByRef S1$, ByRef S2$)
    Dim wordsS1$(), wordsS2$()
    wordsS1 = SplitMultiDelims(S1, " _-")
    wordsS2 = SplitMultiDelims(S2, " _-")
    Dim word1%, word2%, thisD#, wordbest#
    Dim wordsTotal#
    For word1 = LBound(wordsS1) To UBound(wordsS1)
        wordbest = Len(S2)
        For word2 = LBound(wordsS2) To UBound(wordsS2)
            thisD = LevenshteinDistance(wordsS1(word1), wordsS2(word2))
            If thisD < wordbest Then wordbest = thisD
            If thisD = 0 Then GoTo foundbest
        Next word2
foundbest:
        wordsTotal = wordsTotal + wordbest
    Next word1
    valueWords = wordsTotal
End Function

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' SplitMultiDelims
' This function splits Text into an array of substrings, each substring
' delimited by any character in DelimChars. Only a single character
' may be a delimiter between two substrings, but DelimChars may
' contain any number of delimiter characters. It returns a single element
' array containing all of text if DelimChars is empty, or a 1 or greater
' element array if the Text is successfully split into substrings.
' If IgnoreConsecutiveDelimiters is true, empty array elements will not occur.
' If Limit greater than 0, the function will only split Text into 'Limit'
' array elements or less. The last element will contain the rest of Text.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Function SplitMultiDelims(ByRef Text As String, ByRef DelimChars As String, _
        Optional ByVal IgnoreConsecutiveDelimiters As Boolean = False, _
        Optional ByVal Limit As Long = -1) As String()
    Dim ElemStart As Long, N As Long, M As Long, Elements As Long
    Dim lDelims As Long, lText As Long
    Dim Arr() As String

    lText = Len(Text)
    lDelims = Len(DelimChars)
    If lDelims = 0 Or lText = 0 Or Limit = 1 Then
        ReDim Arr(0 To 0)
        Arr(0) = Text
        SplitMultiDelims = Arr
        Exit Function
    End If
    ReDim Arr(0 To IIf(Limit = -1, lText - 1, Limit))

    Elements = 0: ElemStart = 1
    For N = 1 To lText
        If InStr(DelimChars, Mid(Text, N, 1)) Then
            Arr(Elements) = Mid(Text, ElemStart, N - ElemStart)
            If IgnoreConsecutiveDelimiters Then
                If Len(Arr(Elements)) > 0 Then Elements = Elements + 1
            Else
                Elements = Elements + 1
            End If
            ElemStart = N + 1
            If Elements + 1 = Limit Then Exit For
        End If
    Next N
    'Get the last token terminated by the end of the string into the array
    If ElemStart <= lText Then Arr(Elements) = Mid(Text, ElemStart)
    'Since the end of string counts as the terminating delimiter, if the last character
    'was also a delimiter, we treat the two as consecutive, and so ignore the last elemnent
    If IgnoreConsecutiveDelimiters Then If Len(Arr(Elements)) = 0 Then Elements = Elements - 1

    ReDim Preserve Arr(0 To Elements) 'Chop off unused array elements
    SplitMultiDelims = Arr
End Function

Measures of Similarity

Using these two metrics, and a third which simply computes the distance between two strings, I have a series of variables which I can run an optimization algorithm to achieve the greatest number of matches. Fuzzy string matching is, itself, a fuzzy science, and so by creating linearly independent metrics for measuring string similarity, and having a known set of strings we wish to match to each other, we can find the parameters that, for our specific styles of strings, give the best fuzzy match results.

Initially, the goal of the metric was to have a low search value for for an exact match, and increasing search values for increasingly permuted measures. In an impractical case, this was fairly easy to define using a set of well defined permutations, and engineering the final formula such that they had increasing search values results as desired.

Fuzzy String Matching Permutations

In the above screenshot, I tweaked my heuristic to come up with something that I felt scaled nicely to my perceived difference between the search term and result. The heuristic I used for Value Phrase in the above spreadsheet was =valuePhrase(A2,B2)-0.8*ABS(LEN(B2)-LEN(A2)). I was effectively reducing the penalty of the Levenstein distance by 80% of the difference in the length of the two "phrases". This way, "phrases" that have the same length suffer the full penalty, but "phrases" which contain 'additional information' (longer) but aside from that still mostly share the same characters suffer a reduced penalty. I used the Value Words function as is, and then my final SearchVal heuristic was defined as =MIN(D2,E2)*0.8+MAX(D2,E2)*0.2 - a weighted average. Whichever of the two scores was lower got weighted 80%, and 20% of the higher score. This was just a heuristic that suited my use case to get a good match rate. These weights are something that one could then tweak to get the best match rate with their test data.

Fuzzy String Matching Value Phrase

Fuzzy String Matching Value Words

As you can see, the last two metrics, which are fuzzy string matching metrics, already have a natural tendency to give low scores to strings that are meant to match (down the diagonal). This is very good.

Application To allow the optimization of fuzzy matching, I weight each metric. As such, every application of fuzzy string match can weight the parameters differently. The formula that defines the final score is a simply combination of the metrics and their weights:

value = Min(phraseWeight*phraseValue, wordsWeight*wordsValue)*minWeight
      + Max(phraseWeight*phraseValue, wordsWeight*wordsValue)*maxWeight
      + lengthWeight*lengthValue

Using an optimization algorithm (neural network is best here because it is a discrete, multi-dimentional problem), the goal is now to maximize the number of matches. I created a function that detects the number of correct matches of each set to each other, as can be seen in this final screenshot. A column or row gets a point if the lowest score is assigned the the string that was meant to be matched, and partial points are given if there is a tie for the lowest score, and the correct match is among the tied matched strings. I then optimized it. You can see that a green cell is the column that best matches the current row, and a blue square around the cell is the row that best matches the current column. The score in the bottom corner is roughly the number of successful matches and this is what we tell our optimization problem to maximize.

Fuzzy String Matching Optimized Metric

The algorithm was a wonderful success, and the solution parameters say a lot about this type of problem. You'll notice the optimized score was 44, and the best possible score is 48. The 5 columns at the end are decoys, and do not have any match at all to the row values. The more decoys there are, the harder it will naturally be to find the best match.

In this particular matching case, the length of the strings are irrelevant, because we are expecting abbreviations that represent longer words, so the optimal weight for length is -0.3, which means we do not penalize strings which vary in length. We reduce the score in anticipation of these abbreviations, giving more room for partial word matches to supersede non-word matches that simply require less substitutions because the string is shorter.

The word weight is 1.0 while the phrase weight is only 0.5, which means that we penalize whole words missing from one string and value more the entire phrase being intact. This is useful because a lot of these strings have one word in common (the peril) where what really matters is whether or not the combination (region and peril) are maintained.

Finally, the min weight is optimized at 10 and the max weight at 1. What this means is that if the best of the two scores (value phrase and value words) isn't very good, the match is greatly penalized, but we don't greatly penalize the worst of the two scores. Essentially, this puts emphasis on requiring either the valueWord or valuePhrase to have a good score, but not both. A sort of "take what we can get" mentality.

It's really fascinating what the optimized value of these 5 weights say about the sort of fuzzy string matching taking place. For completely different practical cases of fuzzy string matching, these parameters are very different. I've used it for 3 separate applications so far.

While unused in the final optimization, a benchmarking sheet was established which matches columns to themselves for all perfect results down the diagonal, and lets the user change parameters to control the rate at which scores diverge from 0, and note innate similarities between search phrases (which could in theory be used to offset false positives in the results)

Fuzzy String Matching Benchmark

Further Applications

This solution has potential to be used anywhere where the user wishes to have a computer system identify a string in a set of strings where there is no perfect match. (Like an approximate match vlookup for strings).


So what you should take from this, is that you probably want to use a combination of high level heuristics (finding words from one phrase in the other phrase, length of both phrases, etc) along with the implementation of the Levenshtein distance algorithm. Because deciding which is the "best" match is a heuristic (fuzzy) determination - you'll have to come up with a set of weights for any metrics you come up with to determine similarity.

With the appropriate set of heuristics and weights, you'll have your comparison program quickly making the decisions that you would have made.

Javascript - object key->value

obj["a"] is equivalent to obj.a so use obj[name] you get "A"

Select subset of columns in data.table R

This seems an improvement:

> cols<-!(colnames(dt) %in% c("V1","V2","V3","V5"))
> new_dt<-subset(dt,,cols)
> cor(new_dt)
            V4          V6          V7          V8         V9         V10
V4   1.0000000  0.14141578 -0.44466832  0.23697216 -0.1020074  0.48171747
V6   0.1414158  1.00000000 -0.21356218 -0.08510977 -0.1884202 -0.22242274
V7  -0.4446683 -0.21356218  1.00000000 -0.02050846  0.3209454 -0.15021528
V8   0.2369722 -0.08510977 -0.02050846  1.00000000  0.4627034 -0.07020571
V9  -0.1020074 -0.18842023  0.32094540  0.46270335  1.0000000 -0.19224973
V10  0.4817175 -0.22242274 -0.15021528 -0.07020571 -0.1922497  1.00000000

This one is not quite as easy to grasp but might have use for situations there there were a need to specify columns by a numeric vector:

subset(dt, , !grepl(paste0("V", c(1:3,5),collapse="|"),colnames(dt) ))

Convert a String to Modified Camel Case in Java or Title Case as is otherwise called

You can easily write the method to do that :

  public static String toCamelCase(final String init) {
    if (init == null)
        return null;

    final StringBuilder ret = new StringBuilder(init.length());

    for (final String word : init.split(" ")) {
        if (!word.isEmpty()) {
            ret.append(Character.toUpperCase(word.charAt(0)));
            ret.append(word.substring(1).toLowerCase());
        }
        if (!(ret.length() == init.length()))
            ret.append(" ");
    }

    return ret.toString();
}

How do I access (read, write) Google Sheets spreadsheets with Python?

The latest google api docs document how to write to a spreadsheet with python but it's a little difficult to navigate to. Here is a link to an example of how to append.

The following code is my first successful attempt at appending to a google spreadsheet.

import httplib2
import os

from apiclient import discovery
import oauth2client
from oauth2client import client
from oauth2client import tools

try:
    import argparse
    flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
except ImportError:
    flags = None

# If modifying these scopes, delete your previously saved credentials
# at ~/.credentials/sheets.googleapis.com-python-quickstart.json
SCOPES = 'https://www.googleapis.com/auth/spreadsheets'
CLIENT_SECRET_FILE = 'client_secret.json'
APPLICATION_NAME = 'Google Sheets API Python Quickstart'


def get_credentials():
    """Gets valid user credentials from storage.

    If nothing has been stored, or if the stored credentials are invalid,
    the OAuth2 flow is completed to obtain the new credentials.

    Returns:
        Credentials, the obtained credential.
    """
    home_dir = os.path.expanduser('~')
    credential_dir = os.path.join(home_dir, '.credentials')
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)
    credential_path = os.path.join(credential_dir,
                                   'mail_to_g_app.json')

    store = oauth2client.file.Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        if flags:
            credentials = tools.run_flow(flow, store, flags)
        else: # Needed only for compatibility with Python 2.6
            credentials = tools.run(flow, store)
        print('Storing credentials to ' + credential_path)
    return credentials

def add_todo():
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    discoveryUrl = ('https://sheets.googleapis.com/$discovery/rest?'
                    'version=v4')
    service = discovery.build('sheets', 'v4', http=http,
                              discoveryServiceUrl=discoveryUrl)

    spreadsheetId = 'PUT YOUR SPREADSHEET ID HERE'
    rangeName = 'A1:A'

    # https://developers.google.com/sheets/guides/values#appending_values
    values = {'values':[['Hello Saturn',],]}
    result = service.spreadsheets().values().append(
        spreadsheetId=spreadsheetId, range=rangeName,
        valueInputOption='RAW',
        body=values).execute()

if __name__ == '__main__':
    add_todo()

Column calculated from another column?

Generated Column is one of the good approach for MySql version which is 5.7.6 and above.

There are two kinds of Generated Columns:

  • Virtual (default) - column will be calculated on the fly when a record is read from a table
  • Stored - column will be calculated when a new record is written/updated in the table

Both types can have NOT NULL restrictions, but only a stored Generated Column can be a part of an index.

For current case, we are going to use stored generated column. To implement I have considered that both of the values required for calculation are present in table

CREATE TABLE order_details (price DOUBLE, quantity INT, amount DOUBLE AS (price * quantity));

INSERT INTO order_details (price, quantity) VALUES(100,1),(300,4),(60,8);

amount will automatically pop up in table and you can access it directly, also please note that whenever you will update any of the columns, amount will also get updated.

PHP XML how to output nice format

// ##### IN SUMMARY #####

$xmlFilepath = 'test.xml';
echoFormattedXML($xmlFilepath);

/*
 * echo xml in source format
 */
function echoFormattedXML($xmlFilepath) {
    header('Content-Type: text/xml'); // to show source, not execute the xml
    echo formatXML($xmlFilepath); // format the xml to make it readable
} // echoFormattedXML

/*
 * format xml so it can be easily read but will use more disk space
 */
function formatXML($xmlFilepath) {
    $loadxml = simplexml_load_file($xmlFilepath);

    $dom = new DOMDocument('1.0');
    $dom->preserveWhiteSpace = false;
    $dom->formatOutput = true;
    $dom->loadXML($loadxml->asXML());
    $formatxml = new SimpleXMLElement($dom->saveXML());
    //$formatxml->saveXML("testF.xml"); // save as file

    return $formatxml->saveXML();
} // formatXML

CSS: background image on background color

For me this solution didn't work out:

background-color: #6DB3F2;
background-image: url('images/checked.png');

But instead it worked the other way:

<div class="block">
<span>
...
</span>
</div>

the css:

.block{
  background-image: url('img.jpg') no-repeat;
  position: relative;
}

.block::before{
  background-color: rgba(0, 0, 0, 0.37);
  content: '';
  display: block;
  height: 100%;
  position: absolute;
  width: 100%;
}

Show datalist labels but submit the actual value

The solution I use is the following:

<input list="answers" id="answer">
<datalist id="answers">
  <option data-value="42" value="The answer">
</datalist>

Then access the value to be sent to the server using JavaScript like this:

var shownVal = document.getElementById("answer").value;
var value2send = document.querySelector("#answers option[value='"+shownVal+"']").dataset.value;


Hope it helps.

Find a file by name in Visual Studio Code

I believe the action name is "workbench.action.quickOpen".

Case-insensitive search

There are two ways for case insensitive comparison:

  1. Convert strings to upper case and then compare them using the strict operator (===). How strict operator treats operands read stuff at: http://www.thesstech.com/javascript/relational-logical-operators

  2. Pattern matching using string methods:

    Use the "search" string method for case insensitive search. Read about search and other string methods at: http://www.thesstech.com/pattern-matching-using-string-methods

    <!doctype html>
      <html>
        <head>
          <script>
    
            // 1st way
    
            var a = "apple";
            var b = "APPLE";  
            if (a.toUpperCase() === b.toUpperCase()) {
              alert("equal");
            }
    
            //2nd way
    
            var a = " Null and void";
            document.write(a.search(/null/i)); 
    
          </script>
        </head>
    </html>
    

Reset auto increment counter in postgres

If you have a table with an IDENTITY column that you want to reset the next value for you can use the following command:

ALTER TABLE <table name> 
    ALTER COLUMN <column name> 
        RESTART WITH <new value to restart with>;

How to compare binary files to check if they are the same?

For finding flash memory defects, I had to write this script which shows all 1K blocks which contain differences (not only the first one as cmp -b does)

#!/bin/sh

f1=testinput.dat
f2=testoutput.dat

size=$(stat -c%s $f1)
i=0
while [ $i -lt $size ]; do
  if ! r="`cmp -n 1024 -i $i -b $f1 $f2`"; then
    printf "%8x: %s\n" $i "$r"
  fi
  i=$(expr $i + 1024)
done

Output:

   2d400: testinput.dat testoutput.dat differ: byte 3, line 1 is 200 M-^@ 240 M- 
   2dc00: testinput.dat testoutput.dat differ: byte 8, line 1 is 327 M-W 127 W
   4d000: testinput.dat testoutput.dat differ: byte 37, line 1 is 270 M-8 260 M-0
   4d400: testinput.dat testoutput.dat differ: byte 19, line 1 is  46 &  44 $

Disclaimer: I hacked the script in 5 min. It doesn't support command line arguments nor does it support spaces in file names

"android.view.WindowManager$BadTokenException: Unable to add window" on buider.show()

In my case I refactored code and put the creation of the Dialog in a separate class. I only handed over the clicked View because a View contains a context object already. This led to the same error message although all ran on the MainThread.

I then switched to handing over the Activity as well and used its context in the dialog creation -> Everything works now.

    fun showDialogToDeletePhoto(baseActivity: BaseActivity, clickedParent: View, deletePhotoClickedListener: DeletePhotoClickedListener) {
        val dialog = AlertDialog.Builder(baseActivity) // <-- here
   .setTitle(baseActivity.getString(R.string.alert_delete_picture_dialog_title))
...
}

I , can't format the code snippet properly, sorry :(

Change the value in app.config file dynamically

Try:

Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.AppSettings.Settings.Remove("configFilePath");
config.AppSettings.Settings.Add("configFilePath", configFilePath);
config.Save(ConfigurationSaveMode.Modified,true);
config.SaveAs(@"C:\Users\USERNAME\Documents\Visual Studio 2010\Projects\ADI2v1.4\ADI2CE2\App.config",ConfigurationSaveMode.Modified, true); 

Getting list of pixel values from PIL

Or if you want to count white or black pixels

This is also a solution:

from PIL import Image
import operator

img = Image.open("your_file.png").convert('1')
black, white = img.getcolors()

print black[0]
print white[0]

Definition of a Balanced Tree

There are several ways to define "Balanced". The main goal is to keep the depths of all nodes to be O(log(n)).

It appears to me that the balance condition you were talking about is for AVL tree.
Here is the formal definition of AVL tree's balance condition:

For any node in AVL, the height of its left subtree differs by at most 1 from the height of its right subtree.

Next question, what is "height"?

The "height" of a node in a binary tree is the length of the longest path from that node to a leaf.

There is one weird but common case:

People define the height of an empty tree to be (-1).

For example, root's left child is null:

              A  (Height = 2)
           /     \
(height =-1)       B (Height = 1) <-- Unbalanced because 1-(-1)=2 >1
                    \
                     C (Height = 0)

Two more examples to determine:

Yes, A Balanced Tree Example:

        A (h=3)
     /     \
 B(h=1)     C (h=2)        
/          /   \
D (h=0)  E(h=0)  F (h=1)
               /
              G (h=0)

No, Not A Balanced Tree Example:

        A (h=3)
     /     \
 B(h=0)     C (h=2)        <-- Unbalanced: 2-0 =2 > 1
           /   \
        E(h=1)  F (h=0)
        /     \
      H (h=0)   G (h=0)      

Warning about `$HTTP_RAW_POST_DATA` being deprecated

I experienced the same issue on nginx server (DigitalOcean) - all I had to do is to log in as root and modify the file /etc/php5/fpm/php.ini.

To find the line with the always_populate_raw_post_data I first run grep:

grep -n 'always_populate_raw_post_data' php.ini

That returned the line 704

704:;always_populate_raw_post_data = -1

Then simply open php.ini on that line with vi editor:

vi +704 php.ini

Remove the semi colon to uncomment it and save the file :wq

Lastly reboot the server and the error went away.

Video file formats supported in iPhone

The short answer is the iPhone supports H.264 video, High profile and AAC audio, in container formats .mov, .mp4, or MPEG Segment .ts. MPEG Segment files are used for HTTP Live Streaming.

  • For maximum compatibility with Android and desktop browsers, use H.264 + AAC in an .mp4 container.
  • For extended length videos longer than 10 minutes you must use HTTP Live Streaming, which is H.264 + AAC in a series of small .ts container files (see App Store Review Guidelines rule 2.5.7).

Video

On the iPhone, H.264 is the only game in town. [1]

There are several different feature tiers or "profiles" available in H.264. All modern iPhones (3GS and above) support the High profile. These profiles are basically three different levels of algorithm "tricks" used to compress the video. More tricks give better compression, but require more CPU or dedicated hardware to decode. This is a table that lists the differences between the different profiles.

[1] Interestingly, Apple's own Facetime uses the newer H.265 (HEVC) video codec. However right now (August 2017) there is no Apple-provided library that gives access to a HEVC codec to developers. This is expected to change at some point.

In talking about what video format the iPhone supports, a distinction should be made between what the hardware can support, and what the (much lower) limits are for playback when streaming over a network.

The only data given about hardware video support by Apple about the current generation of iPhones (SE, 6S, 6S Plus, 7, 7 Plus) is that they support

4K [3840x2160] video recording at 30 fps

1080p [1920x1080] HD video recording at 30 fps or 60 fps.

Obviously the phone can play back what it can record, so we can guess that 3840x2160 at 30 fps and 1920x1080 at 60 fps represent design limits of the phone. In addition, the screen size on the 6S Plus and 7 Plus is 1920x1080. So if you're interested in playback on the phone, it doesn't make sense to send over more pixels then the screen can draw.

However, streaming video is a different matter. Since networks are slow and video is huge, it's typical to use lower resolutions, bitrates, and frame rates than the device's theoretical maximum.

The most detailed document giving recommendations for streaming is TN2224 Best Practices for Creating and Deploying HTTP Live Streaming Media for Apple Devices. Figure 3 in that document gives a table of recommended streaming parameters:

Table of Apple recommended video encoding settings This table is from May 2016.

As you can see, Apple recommends the relatively low resolution of 768x432 as the highest recommended resolution for streaming over a cellular network. Of course this is just a recommendation and YMMV.

Audio

The question is about video, but that video generally has one or more audio tracks with it. The iPhone supports a few audio formats, but the most modern and by far most widely used is AAC. The iPhone 7 / 7 Plus, 6S Plus / 6S, SE all support AAC bitrates of 8 to 320 Kbps.

Container

The audio and video tracks go inside a container. The purpose of the container is to combine (interleave) the different tracks together, to store metadata, and to support seeking. The iPhone supports

  1. QuickTime .mov,
  2. MP4, and
  3. MPEG-TS.

The .mov and .mp4 file formats are closely related (.mp4 is in fact based on .mov), however .mp4 is an ISO standard that has much wider support.

As noted above, you have to use MPEG-TS for videos longer than 10 minutes.

Android SDK Setup under Windows 7 Pro 64 bit

If SDK Setup.exe fails, please try to open a command-prompt and run "tools\android.bat" manually. That's all what SDK Setup does, however the current version has a bug in that it doesn't display errors that the batch might output:

 > cd <your-sdk>\tools
 > android.bat

That way you may see a more useful error message.

You must have a java.exe on your %PATH%.

Drop all tables whose names begin with a certain string

I saw this post when I was looking for mysql statement to drop all WordPress tables based on @Xenph Yan here is what I did eventually:

SELECT CONCAT(  'DROP TABLE `', TABLE_NAME,  '`;' ) AS query
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME LIKE  'wp_%'

this will give you the set of drop queries for all tables begins with wp_

How to pass data from Javascript to PHP and vice versa?

I'd use JSON as the format and Ajax (really XMLHttpRequest) as the client->server mechanism.

Algorithm/Data Structure Design Interview Questions

Once when I was interviewing for Microsoft in college, the guy asked me how to detect a cycle in a linked list.

Having discussed in class the prior week the optimal solution to the problem, I started to tell him.

He told me, "No, no, everybody gives me that solution. Give me a different one."

I argued that my solution was optimal. He said, "I know it's optimal. Give me a sub-optimal one."

At the same time, it's a pretty good problem.

Displaying tooltip on mouse hover of a text

As there is nothing in this question (but its age) that requires a solution in Windows.Forms, here is a way to do this in WPF in code-behind.

TextBlock tb = new TextBlock();
tb.Inlines.Add(new Run("Background indicates packet repeat status:"));
tb.Inlines.Add(new LineBreak());
tb.Inlines.Add(new LineBreak());
Run r = new Run("White");
r.Background = Brushes.White;
r.ToolTip = "This word has a White background";
tb.Inlines.Add(r);
tb.Inlines.Add(new Run("\t= Identical Packet received at this time."));
tb.Inlines.Add(new LineBreak());
r = new Run("SkyBlue");
r.ToolTip = "This word has a SkyBlue background";
r.Background = new SolidColorBrush(Colors.SkyBlue);
tb.Inlines.Add(r);
tb.Inlines.Add(new Run("\t= Original Packet received at this time."));

myControl.Content = tb;

Name attribute in @Entity and @Table

@Entity is useful with model classes to denote that this is the entity or table

@Table is used to provide any specific name to your table if you want to provide any different name

Note: if you don't use @Table then hibernate consider that @Entity is your table name by default and @Entity must

@Entity    
@Table(name = "emp")     
public class Employee implements java.io.Serializable    
{

}

How I add Headers to http.get or http.post in Typescript and angular 2?

I have used below code in Angular 9. note that it is using http class instead of normal httpClient.

  1. so import Headers from the module, otherwise Headers will be mistaken by typescript headers interface and gives error

    import {Http, Headers, RequestOptionsArgs } from "@angular/http";

  2. and in your method use following sample code and it is breaked down for easier understanding.

    let customHeaders = new Headers({ Authorization: "Bearer " + localStorage.getItem("token")});
    const requestOptions: RequestOptionsArgs = { headers: customHeaders };
    return this.http.get("/api/orders", requestOptions);
    

How to preSelect an html dropdown list with php?

First of all give a name to your select. Then do:

<select name="my_select">
<option value="1" <?= ($_POST['my_select'] == "1")? "selected":"";?>>Yes</options>
<option value="2" <?= ($_POST['my_select'] == "2")? "selected":"";?>>No</options>
<option value="3" <?= ($_POST['my_select'] == "3")? "selected":"";?>>Fine</options>
</select>

What that does is check if what was selected is the same for each and when its found echo "selected".

how to pass variable from shell script to sqlplus

You appear to have a heredoc containing a single SQL*Plus command, though it doesn't look right as noted in the comments. You can either pass a value in the heredoc:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql BUILDING
exit;
EOF

or if BUILDING is $2 in your script:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql $2
exit;
EOF

If your file.sql had an exit at the end then it would be even simpler as you wouldn't need the heredoc:

sqlplus -S user/pass@localhost @/opt/D2RQ/file.sql $2

In your SQL you can then refer to the position parameters using substitution variables:

...
}',SEM_Models('&1'),NULL,
...

The &1 will be replaced with the first value passed to the SQL script, BUILDING; because that is a string it still needs to be enclosed in quotes. You might want to set verify off to stop if showing you the substitutions in the output.


You can pass multiple values, and refer to them sequentially just as you would positional parameters in a shell script - the first passed parameter is &1, the second is &2, etc. You can use substitution variables anywhere in the SQL script, so they can be used as column aliases with no problem - you just have to be careful adding an extra parameter that you either add it to the end of the list (which makes the numbering out of order in the script, potentially) or adjust everything to match:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql total_count BUILDING
exit;
EOF

or:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql total_count $2
exit;
EOF

If total_count is being passed to your shell script then just use its positional parameter, $4 or whatever. And your SQL would then be:

SELECT COUNT(*) as &1
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&2'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

If you pass a lot of values you may find it clearer to use the positional parameters to define named parameters, so any ordering issues are all dealt with at the start of the script, where they are easier to maintain:

define MY_ALIAS = &1
define MY_MODEL = &2

SELECT COUNT(*) as &MY_ALIAS
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&MY_MODEL'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

From your separate question, maybe you just wanted:

SELECT COUNT(*) as &1
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&1'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

... so the alias will be the same value you're querying on (the value in $2, or BUILDING in the original part of the answer). You can refer to a substitution variable as many times as you want.

That might not be easy to use if you're running it multiple times, as it will appear as a header above the count value in each bit of output. Maybe this would be more parsable later:

select '&1' as QUERIED_VALUE, COUNT(*) as TOTAL_COUNT

If you set pages 0 and set heading off, your repeated calls might appear in a neat list. You might also need to set tab off and possibly use rpad('&1', 20) or similar to make that column always the same width. Or get the results as CSV with:

select '&1' ||','|| COUNT(*)

Depends what you're using the results for...

How do I position one image on top of another in HTML?

Here's code that may give you ideas:

<style>
.containerdiv { float: left; position: relative; } 
.cornerimage { position: absolute; top: 0; right: 0; } 
</style>

<div class="containerdiv">
    <img border="0" src="https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png" alt=""">
    <img class="cornerimage" border="0" src="http://www.gravatar.com/avatar/" alt="">
<div>

JSFiddle

I suspect that Espo's solution may be inconvenient because it requires you to position both images absolutely. You may want the first one to position itself in the flow.

Usually, there is a natural way to do that is CSS. You put position: relative on the container element, and then absolutely position children inside it. Unfortunately, you cannot put one image inside another. That's why I needed container div. Notice that I made it a float to make it autofit to its contents. Making it display: inline-block should theoretically work as well, but browser support is poor there.

EDIT: I deleted size attributes from the images to illustrate my point better. If you want the container image to have its default sizes and you don't know the size beforehand, you cannot use the background trick. If you do, it is a better way to go.

How do I delete virtual interface in Linux?

You can use sudo ip link delete to remove the interface.

How to change theme for AlertDialog

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Title");
builder.setMessage("Description");
builder.setPositiveButton("OK", null);
builder.setNegativeButton("Cancel", null);
builder.show();

Jquery find nearest matching element

You could try:

$(this).closest(".column").prev().find(".inputQty").val();

Docker Networking - nginx: [emerg] host not found in upstream

My problem was that I forgot to specify network alias in docker-compose.yml in php-fpm

    networks:
      - u-online

It is works well!

version: "3"
services:

  php-fpm:
    image: php:7.2-fpm
    container_name: php-fpm
    volumes:           
      - ./src:/var/www/basic/public_html
    ports:
      - 9000:9000
    networks:
      - u-online
      
  nginx: 
    image: nginx:1.19.2
    container_name: nginx   
    depends_on:
      - php-fpm       
    ports:
      - "80:8080"
      - "443:443"
    volumes:
      - ./docker/data/etc/nginx/conf.d/default.conf:/etc/nginx/conf.d/default.conf
      - ./docker/data/etc/nginx/nginx.conf:/etc/nginx/nginx.conf
      - ./src:/var/www/basic/public_html
    networks:
      - u-online

#Docker Networks
networks:
  u-online:
    driver: bridge

How to set component default props on React component

You forgot to close the Class bracket.

_x000D_
_x000D_
class AddAddressComponent extends React.Component {_x000D_
  render() {_x000D_
    let {provinceList,cityList} = this.props_x000D_
    if(cityList === undefined || provinceList === undefined){_x000D_
      console.log('undefined props')_x000D_
    } else {_x000D_
      console.log('defined props')_x000D_
    }_x000D_
_x000D_
    return (_x000D_
      <div>rendered</div>_x000D_
    )_x000D_
  }_x000D_
}_x000D_
_x000D_
AddAddressComponent.contextTypes = {_x000D_
  router: React.PropTypes.object.isRequired_x000D_
};_x000D_
_x000D_
AddAddressComponent.defaultProps = {_x000D_
  cityList: [],_x000D_
  provinceList: [],_x000D_
};_x000D_
_x000D_
AddAddressComponent.propTypes = {_x000D_
  userInfo: React.PropTypes.object,_x000D_
  cityList: React.PropTypes.array.isRequired,_x000D_
  provinceList: React.PropTypes.array.isRequired,_x000D_
}_x000D_
_x000D_
ReactDOM.render(_x000D_
  <AddAddressComponent />,_x000D_
  document.getElementById('app')_x000D_
)
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="app" />
_x000D_
_x000D_
_x000D_

Difference between multitasking, multithreading and multiprocessing?

Multiprogramming: More than one task/program/job/process can reside into the main memory at one point of time. This ability of the OS is called multiprogramming.

Multitasking: More than one task/program/job/process can reside into the same CPU at one point of time. This ability of the OS is called multitasking.

Markdown open a new window link

It is very dependent of the engine that you use for generating html files. If you are using Hugo for generating htmls you have to write down like this:

<a href="https://example.com" target="_blank" rel="noopener"><span>Example Text</span> </a>.

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

You are really talking about serialization, which can take many forms. Since you want small and binary, protocol buffers may be a viable option - giving version tolerance and portability as well. Unlike BinaryFormatter, the protocol buffers wire format doesn't include all the type metadata; just very terse markers to identify data.

In .NET there are a few implementations; in particular

I'd humbly argue that protobuf-net (which I wrote) allows more .NET-idiomatic usage with typical C# classes ("regular" protocol-buffers tends to demand code-generation); for example:

[ProtoContract]
public class Person {
   [ProtoMember(1)]
   public int Id {get;set;}
   [ProtoMember(2)]
   public string Name {get;set;}
}
....
Person person = new Person { Id = 123, Name = "abc" };
Serializer.Serialize(destStream, person);
...
Person anotherPerson = Serializer.Deserialize<Person>(sourceStream);

AngularJS sorting by property

Here is what i did and it works.
I just used a stringified object.

$scope.thread = [ 
  {
    mostRecent:{text:'hello world',timeStamp:12345678 } 
    allMessages:[]
  }
  {MoreThreads...}
  {etc....}
]

<div ng-repeat="message in thread | orderBy : '-mostRecent.timeStamp'" >

if i wanted to sort by text i would do

orderBy : 'mostRecent.text'

Select N random elements from a List<T> in C#

Was thinking about comment by @JohnShedletsky on the accepted answer regarding (paraphrase):

you should be able to to this in O(subset.Length), rather than O(originalList.Length)

Basically, you should be able to generate subset random indices and then pluck them from the original list.

The Method

public static class EnumerableExtensions {

    public static Random randomizer = new Random(); // you'd ideally be able to replace this with whatever makes you comfortable

    public static IEnumerable<T> GetRandom<T>(this IEnumerable<T> list, int numItems) {
        return (list as T[] ?? list.ToArray()).GetRandom(numItems);

        // because ReSharper whined about duplicate enumeration...
        /*
        items.Add(list.ElementAt(randomizer.Next(list.Count()))) ) numItems--;
        */
    }

    // just because the parentheses were getting confusing
    public static IEnumerable<T> GetRandom<T>(this T[] list, int numItems) {
        var items = new HashSet<T>(); // don't want to add the same item twice; otherwise use a list
        while (numItems > 0 )
            // if we successfully added it, move on
            if( items.Add(list[randomizer.Next(list.Length)]) ) numItems--;

        return items;
    }

    // and because it's really fun; note -- you may get repetition
    public static IEnumerable<T> PluckRandomly<T>(this IEnumerable<T> list) {
        while( true )
            yield return list.ElementAt(randomizer.Next(list.Count()));
    }

}

If you wanted to be even more efficient, you would probably use a HashSet of the indices, not the actual list elements (in case you've got complex types or expensive comparisons);

The Unit Test

And to make sure we don't have any collisions, etc.

[TestClass]
public class RandomizingTests : UnitTestBase {
    [TestMethod]
    public void GetRandomFromList() {
        this.testGetRandomFromList((list, num) => list.GetRandom(num));
    }

    [TestMethod]
    public void PluckRandomly() {
        this.testGetRandomFromList((list, num) => list.PluckRandomly().Take(num), requireDistinct:false);
    }

    private void testGetRandomFromList(Func<IEnumerable<int>, int, IEnumerable<int>> methodToGetRandomItems, int numToTake = 10, int repetitions = 100000, bool requireDistinct = true) {
        var items = Enumerable.Range(0, 100);
        IEnumerable<int> randomItems = null;

        while( repetitions-- > 0 ) {
            randomItems = methodToGetRandomItems(items, numToTake);
            Assert.AreEqual(numToTake, randomItems.Count(),
                            "Did not get expected number of items {0}; failed at {1} repetition--", numToTake, repetitions);
            if(requireDistinct) Assert.AreEqual(numToTake, randomItems.Distinct().Count(),
                            "Collisions (non-unique values) found, failed at {0} repetition--", repetitions);
            Assert.IsTrue(randomItems.All(o => items.Contains(o)),
                        "Some unknown values found; failed at {0} repetition--", repetitions);
        }
    }
}

What is the difference between RTP or RTSP in a streaming server?

Some basics:

RTSP server can be used for dead source as well as for live source. RTSP protocols provides you commands (Like your VCR Remote), and functionality depends upon your implementation.

RTP is real time protocol used for transporting audio and video in real time. Transport used can be unicast, multicast or broadcast, depending upon transport address and port. Besides transporting RTP does lots of things for you like packetization, reordering, jitter control, QoS, support for Lip sync.....

In your case if you want broadcasting streaming server then you need both RTSP (for control) as well as RTP (broadcasting audio and video)

To start with you can go through sample code provided by live555

Simulate low network connectivity for Android

have you tried this? Settings - Networks - More - Mobile Networks - Network mode - Select preferred network (2G for example).

Another method i used was mentioned above. Connect via iPhone hot spot. Hope this helps.

Execute and get the output of a shell command in node.js

Thanks to Renato answer, I have created a really basic example:

const exec = require('child_process').exec

exec('git config --global user.name', (err, stdout, stderr) => console.log(stdout))

It will just print your global git username :)

Delete terminal history in Linux

If you use bash, then the terminal history is saved in a file called .bash_history. Delete it, and history will be gone.

However, for MySQL the better approach is not to enter the password in the command line. If you just specify the -p option, without a value, then you will be prompted for the password and it won't be logged.

Another option, if you don't want to enter your password every time, is to store it in a my.cnf file. Create a file named ~/.my.cnf with something like:

[client]
user = <username>
password = <password>

Make sure to change the file permissions so that only you can read the file.

Of course, this way your password is still saved in a plaintext file in your home directory, just like it was previously saved in .bash_history.

Oracle error : ORA-00905: Missing keyword

Unless there is a single row in the ASSIGNMENT table and ASSIGNMENT_20081120 is a local PL/SQL variable of type ASSIGNMENT%ROWTYPE, this is not what you want.

Assuming you are trying to create a new table and copy the existing data to that new table

CREATE TABLE assignment_20081120
AS
SELECT *
  FROM assignment

Xcode project not showing list of simulators

Just go to Xcode -> Window -> Devices

Click + at the bottom left

Add your new Simulator

How to get the nvidia driver version from the command line?

To expand on ccc's answer, if you want to incorporate querying the card with a script, here is information on Nvidia site on how to do so:

https://nvidia.custhelp.com/app/answers/detail/a_id/3751/~/useful-nvidia-smi-queries

Also, I found this thread researching powershell. Here is an example command that runs the utility to get the true memory available on the GPU to get you started.

# get gpu metrics
$cmd = "& 'C:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi' --query-gpu=name,utilization.memory,driver_version --format=csv"
$gpuinfo = invoke-expression $cmd | ConvertFrom-CSV
$gpuname = $gpuinfo.name
$gpuutil = $gpuinfo.'utilization.memory [%]'.Split(' ')[0]
$gpuDriver = $gpuinfo.driver_version

What's the difference between "2*2" and "2**2" in Python?

Try:

2**3*2

and

2*3*2

to see the difference.

** is the operator for "power of". In your particular operation, 2 to the power of 2 yields the same as 2 times 2.

Drop-down box dependent on the option selected in another drop-down box

In this jsfiddle you'll find a solution I deviced. The idea is to have a selector pair in html and use (plain) javascript to filter the options in the dependent selector, based on the selected option of the first. For example:

<select id="continents">
 <option value = 0>All</option>   
 <option value = 1>Asia</option>
 <option value = 2>Europe</option>
 <option value = 3>Africa</option>
</select> 
<select id="selectcountries"></select>

Uses (in the jsFiddle)

 MAIN.createRelatedSelector
     ( document.querySelector('#continents')           // from select element
      ,document.querySelector('#selectcountries')      // to select element
      ,{                                               // values object 
        Asia: ['China','Japan','North Korea',
               'South Korea','India','Malaysia',
               'Uzbekistan'],
        Europe: ['France','Belgium','Spain','Netherlands','Sweden','Germany'],
        Africa: ['Mali','Namibia','Botswana','Zimbabwe','Burkina Faso','Burundi']
      }
      ,function(a,b){return a>b ? 1 : a<b ? -1 : 0;}   // sort method
 );

[Edit 2021] or use data-attributes, something like:

_x000D_
_x000D_
document.addEventListener("change", checkSelect);

function checkSelect(evt) {
  const origin = evt.target;

  if (origin.dataset.dependentSelector) {
    const selectedOptFrom = origin.querySelector("option:checked")
      .dataset.dependentOpt || "n/a";
    const addRemove = optData => (optData || "") === selectedOptFrom 
      ? "add" : "remove";
    document.querySelectorAll(`${origin.dataset.dependentSelector} option`)
      .forEach( opt => 
        opt.classList[addRemove(opt.dataset.fromDependent)]("display") );
  }
}
_x000D_
[data-from-dependent] {
  display: none;
}

[data-from-dependent].display {
  display: initial;
}
_x000D_
<select id="source" name="source" data-dependent-selector="#status">
  <option>MANUAL</option>
  <option data-dependent-opt="ONLINE">ONLINE</option>
  <option data-dependent-opt="UNKNOWN">UNKNOWN</option>
</select>

<select id="status" name="status">
  <option>OPEN</option>
  <option>DELIVERED</option>
  <option data-from-dependent="ONLINE">SHIPPED</option>
  <option data-from-dependent="UNKNOWN">SHOULD SELECT</option>
  <option data-from-dependent="UNKNOWN">MAYBE IN TRANSIT</option>
</select>
_x000D_
_x000D_
_x000D_

Convert UTF-8 with BOM to UTF-8 with no BOM in Python

I found this question because having trouble with configparser.ConfigParser().read(fp) when opening files with UTF8 BOM header.

For those who are looking for a solution to remove the header so that ConfigPhaser could open the config file instead of reporting an error of: File contains no section headers, please open the file like the following:

configparser.ConfigParser().read(config_file_path, encoding="utf-8-sig")

This could save you tons of effort by making the remove of the BOM header of the file unnecessary.

(I know this sounds unrelated, but hopefully this could help people struggling like me.)

Comparing strings in Java

did the same here needed to show "success" twice response is data from PHP

 String res=response.toString().trim;

                            Toast.makeText(sign_in.this,res,Toast.LENGTH_SHORT).show();
    if ( res.compareTo("success")==0){
    Toast.makeText(this,res,Toast.LENGTH_SHORT).show();
    }

How to serve static files in Flask

The preferred method is to use nginx or another web server to serve static files; they'll be able to do it more efficiently than Flask.

However, you can use send_from_directory to send files from a directory, which can be pretty convenient in some situations:

from flask import Flask, request, send_from_directory

# set the project root directory as the static folder, you can set others.
app = Flask(__name__, static_url_path='')

@app.route('/js/<path:path>')
def send_js(path):
    return send_from_directory('js', path)

if __name__ == "__main__":
    app.run()

Do not use send_file or send_static_file with a user-supplied path.

send_static_file example:

from flask import Flask, request
# set the project root directory as the static folder, you can set others.
app = Flask(__name__, static_url_path='')

@app.route('/')
def root():
    return app.send_static_file('index.html')

Open files in 'rt' and 'wt' modes

The 'r' is for reading, 'w' for writing and 'a' is for appending.

The 't' represents text mode as apposed to binary mode.

Several times here on SO I've seen people using rt and wt modes for reading and writing files.

Edit: Are you sure you saw rt and not rb?

These functions generally wrap the fopen function which is described here:

http://www.cplusplus.com/reference/cstdio/fopen/

As you can see it mentions the use of b to open the file in binary mode.

The document link you provided also makes reference to this b mode:

Appending 'b' is useful even on systems that don’t treat binary and text files differently, where it serves as documentation.

How to override the properties of a CSS class using another CSS class

If you list the bakground-none class after the other classes, its properties will override those already set. There is no need to use !important here.

For example:

.red { background-color: red; }
.background-none { background: none; }

and

<a class="red background-none" href="#carousel">...</a>

The link will not have a red background. Please note that this only overrides properties that have a selector that is less or equally specific.

Get querystring from URL using jQuery

We do it this way...

String.prototype.getValueByKey = function (k) {
    var p = new RegExp('\\b' + k + '\\b', 'gi');
    return this.search(p) != -1 ? decodeURIComponent(this.substr(this.search(p) + k.length + 1).substr(0, this.substr(this.search(p) + k.length + 1).search(/(&|;|$)/))) : "";
};

Sleep Command in T-SQL?

Look at the WAITFOR command.

E.g.

-- wait for 1 minute
WAITFOR DELAY '00:01'

-- wait for 1 second
WAITFOR DELAY '00:00:01'

This command allows you a high degree of precision but is only accurate within 10ms - 16ms on a typical machine as it relies on GetTickCount. So, for example, the call WAITFOR DELAY '00:00:00:001' is likely to result in no wait at all.

How to remove multiple deleted files in Git repository

When I have a lot of files I've deleted that are unstaged for commit, you can git rm them all in one show with:

for i in `git status | grep deleted | awk '{print $3}'`; do git rm $i; done

As question answerer mentioned, be careful with git rm.

Read and Write CSV files including unicode with Python 2.7

I couldn't respond to Mark above, but I just made one modification which fixed the error which was caused if data in the cells was not unicode, i.e. float or int data. I replaced this line into the UnicodeWriter function: "self.writer.writerow([s.encode("utf-8") if type(s)==types.UnicodeType else s for s in row])" so that it became:

class UnicodeWriter:
    def __init__(self, f, dialect=csv.excel, encoding="utf-8-sig", **kwds):
       self.queue = cStringIO.StringIO()
        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()
    def writerow(self, row):
        '''writerow(unicode) -> None
        This function takes a Unicode string and encodes it to the output.
        '''
        self.writer.writerow([s.encode("utf-8") if type(s)==types.UnicodeType else s for s in row])
        data = self.queue.getvalue()
        data = data.decode("utf-8")
        data = self.encoder.encode(data)
        self.stream.write(data)
        self.queue.truncate(0)

    def writerows(self, rows):
        for row in rows:
            self.writerow(row)

You will also need to "import types".

Design Documents (High Level and Low Level Design Documents)

High-Level Design (HLD) involves decomposing a system into modules, and representing the interfaces & invocation relationships among modules. An HLD is referred to as software architecture.

LLD, also known as a detailed design, is used to design internals of the individual modules identified during HLD i.e. data structures and algorithms of the modules are designed and documented.

Now, HLD and LLD are actually used in traditional Approach (Function-Oriented Software Design) whereas, in OOAD, the system is seen as a set of objects interacting with each other.

As per the above definitions, a high-level design document will usually include a high-level architecture diagram depicting the components, interfaces, and networks that need to be further specified or developed. The document may also depict or otherwise refer to work flows and/or data flows between component systems.

Class diagrams with all the methods and relations between classes come under LLD. Program specs are covered under LLD. LLD describes each and every module in an elaborate manner so that the programmer can directly code the program based on it. There will be at least 1 document for each module. The LLD will contain - a detailed functional logic of the module in pseudo code - database tables with all elements including their type and size - all interface details with complete API references(both requests and responses) - all dependency issues - error message listings - complete inputs and outputs for a module.

C# winforms combobox dynamic autocomplete

Here is my final solution. It works fine with a large amount of data. I use Timer to make sure the user want find current value. It looks like complex but it doesn't. Thanks to Max Lambertini for the idea.

        private bool _canUpdate = true; 

        private bool _needUpdate = false;       

        //If text has been changed then start timer
        //If the user doesn't change text while the timer runs then start search
        private void combobox1_TextChanged(object sender, EventArgs e)
        {
            if (_needUpdate)
            {
                if (_canUpdate)
                {
                    _canUpdate = false;
                    UpdateData();                   
                }
                else
                {
                    RestartTimer();
                }
            }
        }

        private void UpdateData()
        {
            if (combobox1.Text.Length > 1)
            {
                List<string> searchData = Search.GetData(combobox1.Text);
                HandleTextChanged(searchData);
            }
        }       

        //If an item was selected don't start new search
        private void combobox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            _needUpdate = false;
        }

        //Update data only when the user (not program) change something
        private void combobox1_TextUpdate(object sender, EventArgs e)
        {
            _needUpdate = true;
        }

        //While timer is running don't start search
        //timer1.Interval = 1500;
        private void RestartTimer()
        {
            timer1.Stop();
            _canUpdate = false;
            timer1.Start();
        }

        //Update data when timer stops
        private void timer1_Tick(object sender, EventArgs e)
        {
            _canUpdate = true;
            timer1.Stop();
            UpdateData();
        }

        //Update combobox with new data
        private void HandleTextChanged(List<string> dataSource)
        {
            var text = combobox1.Text;

            if (dataSource.Count() > 0)
            {
                combobox1.DataSource = dataSource;  

                var sText = combobox1.Items[0].ToString();
                combobox1.SelectionStart = text.Length;
                combobox1.SelectionLength = sText.Length - text.Length;
                combobox1.DroppedDown = true;


                return;
            }
            else
            {
                combobox1.DroppedDown = false;
                combobox1.SelectionStart = text.Length;
            }
        }

This solution isn't very cool. So if someone has another solution please share it with me.

How do you enable auto-complete functionality in Visual Studio C++ express edition?

I came across over the following post: http://blogs.msdn.com/b/raulperez/archive/2010/03/19/c-intellisense-options.aspx

The issue is that the "IntelliSense" option in c++ is disabled. This link explains about the IntelliSense database configuration and options.

After enabling the database you must close and reopen visual studio for autocomplete use 'ctrl'+'space'

What are the true benefits of ExpandoObject?

One advantage is for binding scenarios. Data grids and property grids will pick up the dynamic properties via the TypeDescriptor system. In addition, WPF data binding will understand dynamic properties, so WPF controls can bind to an ExpandoObject more readily than a dictionary.

Interoperability with dynamic languages, which will be expecting DLR properties rather than dictionary entries, may also be a consideration in some scenarios.

Docker: How to delete all local Docker images

Use this to delete everything:

docker system prune -a --volumes

Remove all unused containers, volumes, networks and images

WARNING! This will remove:
    - all stopped containers
    - all networks not used by at least one container
    - all volumes not used by at least one container
    - all images without at least one container associated to them
    - all build cache

https://docs.docker.com/engine/reference/commandline/system_prune/#extended-description

Javascript format date / time

I don't think that can be done RELIABLY with built in methods on the native Date object. The toLocaleString method gets close, but if I am remembering correctly, it won't work correctly in IE < 10. If you are able to use a library for this task, MomentJS is a really amazing library; and it makes working with dates and times easy. Otherwise, I think you will have to write a basic function to give you the format that you are after.

function formatDate(date) {
    var year = date.getFullYear(),
        month = date.getMonth() + 1, // months are zero indexed
        day = date.getDate(),
        hour = date.getHours(),
        minute = date.getMinutes(),
        second = date.getSeconds(),
        hourFormatted = hour % 12 || 12, // hour returned in 24 hour format
        minuteFormatted = minute < 10 ? "0" + minute : minute,
        morning = hour < 12 ? "am" : "pm";

    return month + "/" + day + "/" + year + " " + hourFormatted + ":" +
            minuteFormatted + morning;
}

Getting Date or Time only from a DateTime Object

You can also use DateTime.Now.ToString("yyyy-MM-dd") for the date, and DateTime.Now.ToString("hh:mm:ss") for the time.

Removing Conda environment

Because you can only deactivate the active environment, so conda deactivate does not need nor accept arguments. The error message is very explicit here.

Just call conda deactivate https://github.com/conda/conda/issues/7296#issuecomment-389504269

SQL Server - find nth occurrence in a string

DECLARE @LEN INT
DECLARE @VAR VARCHAR(20)
SET @VAR = 'HELLO WORLD'
SET @LEN = LEN(@VAR)
--SELECT @LEN
SELECT PATINDEX('%O%',SUBSTRING(@VAR,PATINDEX('%O%' ,@VAR) +  1 ,PATINDEX('%O%',@VAR) + 1)) + PATINDEX('%O%',@VAR)

Can git undo a checkout of unstaged files

Maybe your changes are not lost. Check "git reflog"

I quote the article below:

"Basically every action you perform inside of Git where data is stored, you can find it inside of the reflog. Git tries really hard not to lose your data, so if for some reason you think it has, chances are you can dig it out using git reflog"

See details:

http://gitready.com/intermediate/2009/02/09/reflog-your-safety-net.html

MySQL: Error dropping database (errno 13; errno 17; errno 39)

in linux , Just go to "/var/lib/mysql" right click and (open as adminstrator), find the folder corresponding to your database name inside mysql folder and delete it. that's it. Database is dropped.

Search all tables, all columns for a specific value SQL Server

I've just updated my blog post to correct the error in the script that you were having Jeff, you can see the updated script here: Search all fields in SQL Server Database

As requested, here's the script in case you want it but I'd recommend reviewing the blog post as I do update it from time to time

DECLARE @SearchStr nvarchar(100)
SET @SearchStr = '## YOUR STRING HERE ##'
 
 
-- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.
-- Purpose: To search all columns of all tables for a given search string
-- Written by: Narayana Vyas Kondreddi
-- Site: http://vyaskn.tripod.com
-- Updated and tested by Tim Gaunt
-- http://www.thesitedoctor.co.uk
-- http://blogs.thesitedoctor.co.uk/tim/2010/02/19/Search+Every+Table+And+Field+In+A+SQL+Server+Database+Updated.aspx
-- Tested on: SQL Server 7.0, SQL Server 2000, SQL Server 2005 and SQL Server 2010
-- Date modified: 03rd March 2011 19:00 GMT
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
 
SET NOCOUNT ON
 
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
 
WHILE @TableName IS NOT NULL
 
BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM     INFORMATION_SCHEMA.TABLES
        WHERE         TABLE_TYPE = 'BASE TABLE'
            AND    QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND    OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )
 
    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
         
    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM     INFORMATION_SCHEMA.COLUMNS
            WHERE         TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND    TABLE_NAME    = PARSENAME(@TableName, 1)
                AND    DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal')
                AND    QUOTENAME(COLUMN_NAME) > @ColumnName
        )
 
        IF @ColumnName IS NOT NULL
         
        BEGIN
            INSERT INTO #Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
            )
        END
    END   
END
 
SELECT ColumnName, ColumnValue FROM #Results
 
DROP TABLE #Results

Use URI builder in Android or create URL with variables

for the example in the second Answer I used this technique for the same URL

http://api.example.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7

Uri.Builder builder = new Uri.Builder();
            builder.scheme("https")
                    .authority("api.openweathermap.org")
                    .appendPath("data")
                    .appendPath("2.5")
                    .appendPath("forecast")
                    .appendPath("daily")
                    .appendQueryParameter("q", params[0])
                    .appendQueryParameter("mode", "json")
                    .appendQueryParameter("units", "metric")
                    .appendQueryParameter("cnt", "7")
                    .appendQueryParameter("APPID", BuildConfig.OPEN_WEATHER_MAP_API_KEY);

then after finish building it get it as URL like this

URL url = new URL(builder.build().toString());

and open a connection

  HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

and if link is simple like location uri, for example

geo:0,0?q=29203

Uri geoLocation = Uri.parse("geo:0,0?").buildUpon()
            .appendQueryParameter("q",29203).build();

Python pip install module is not found. How to link python to pip location?

For me the problem was that I had weird configuration settings in file pydistutils.cfg

Try running rm ~/.pydistutils.cfg

Class method decorator with self arguments?

I know this is an old question, but this solution has not been mentioned yet, hopefully it may help someone even today, after 8 years.

So, what about wrapping a wrapper? Let's assume one cannot change the decorator neither decorate those methods in init (they may be @property decorated or whatever). There is always a possibility to create custom, class-specific decorator that will capture self and subsequently call the original decorator, passing runtime attribute to it.

Here is a working example (f-strings require python 3.6):

import functools

# imagine this is at some different place and cannot be changed
def check_authorization(some_attr, url):
        def decorator(func):
                @functools.wraps(func)
                def wrapper(*args, **kwargs):
                        print(f"checking authorization for '{url}'...")
                        return func(*args, **kwargs)
                return wrapper
        return decorator

# another dummy function to make the example work
def do_work():
        print("work is done...")

###################
# wrapped wrapper #
###################
def custom_check_authorization(some_attr):
        def decorator(func):
                # assuming this will be used only on this particular class
                @functools.wraps(func)
                def wrapper(self, *args, **kwargs):
                        # get url
                        url = self.url
                        # decorate function with original decorator, pass url
                        return check_authorization(some_attr, url)(func)(self, *args, **kwargs)
                return wrapper
        return decorator
        
#############################
# original example, updated #
#############################
class Client(object):
        def __init__(self, url):
                self.url = url
    
        @custom_check_authorization("some_attr")
        def get(self):
                do_work()

# create object
client = Client(r"https://stackoverflow.com/questions/11731136/class-method-decorator-with-self-arguments")

# call decorated function
client.get()

output:

checking authorisation for 'https://stackoverflow.com/questions/11731136/class-method-decorator-with-self-arguments'...
work is done...

In Javascript, how do I check if an array has duplicate values?

Another approach (also for object/array elements within the array1) could be2:

function chkDuplicates(arr,justCheck){
  var len = arr.length, tmp = {}, arrtmp = arr.slice(), dupes = [];
  arrtmp.sort();
  while(len--){
   var val = arrtmp[len];
   if (/nul|nan|infini/i.test(String(val))){
     val = String(val);
    }
    if (tmp[JSON.stringify(val)]){
       if (justCheck) {return true;}
       dupes.push(val);
    }
    tmp[JSON.stringify(val)] = true;
  }
  return justCheck ? false : dupes.length ? dupes : null;
}
//usages
chkDuplicates([1,2,3,4,5],true);                           //=> false
chkDuplicates([1,2,3,4,5,9,10,5,1,2],true);                //=> true
chkDuplicates([{a:1,b:2},1,2,3,4,{a:1,b:2},[1,2,3]],true); //=> true
chkDuplicates([null,1,2,3,4,{a:1,b:2},NaN],true);          //=> false
chkDuplicates([1,2,3,4,5,1,2]);                            //=> [1,2]
chkDuplicates([1,2,3,4,5]);                                //=> null

See also...

1 needs a browser that supports JSON, or a JSON library if not.
2 edit: function can now be used for simple check or to return an array of duplicate values

Convert Pandas column containing NaNs to dtype `int`

First remove the rows which contain NaN. Then do Integer conversion on remaining rows. At Last insert the removed rows again. Hope it will work

Examples of GoF Design Patterns in Java's core libraries

Even though I'm sort of a broken clock with this one, Java XML API uses Factory a lot. I mean just look at this:

Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(source);
String title = XPathFactory.newInstance().newXPath().evaluate("//title", doc);

...and so on and so forth.

Additionally various Buffers (StringBuffer, ByteBuffer, StringBuilder) use Builder.

Changing permissions via chmod at runtime errors with "Operation not permitted"

$ sudo chmod ...

You need to either be the owner of the file or be the superuser, i.e., user root. If you own the directory but not the file, you can copy the file, rm the original, then mv it back, and then you will be able to chown it.

The easy way to temporarily be root is to run the command via sudo. ($ man 8 sudo)

Convert SVG to image (JPEG, PNG, etc.) in the browser

jbeard4 solution worked beautifully.

I'm using Raphael SketchPad to create an SVG. Link to the files in step 1.

For a Save button (id of svg is "editor", id of canvas is "canvas"):

$("#editor_save").click(function() {

// the canvg call that takes the svg xml and converts it to a canvas
canvg('canvas', $("#editor").html());

// the canvas calls to output a png
var canvas = document.getElementById("canvas");
var img = canvas.toDataURL("image/png");
// do what you want with the base64, write to screen, post to server, etc...
});

The remote end hung up unexpectedly while git cloning

It worked for me after I tried it.

git config --global http.postBuffer 2048M
git config --global http.maxRequestBuffer 1024M
git config --global core.compression 9

git config --global ssh.postBuffer 2048M
git config --global ssh.maxRequestBuffer 1024M

git config --global pack.windowMemory 256m 
git config --global pack.packSizeLimit 256m

Thank you for all

What are all codecs and formats supported by FFmpeg?

Codecs proper:

ffmpeg -codecs

Formats:

ffmpeg -formats

How can I run an external command asynchronously from Python?

This is covered by Python 3 Subprocess Examples under "Wait for command to terminate asynchronously":

import asyncio

proc = await asyncio.create_subprocess_exec(
    'ls','-lha',
    stdout=asyncio.subprocess.PIPE,
    stderr=asyncio.subprocess.PIPE)

# do something else while ls is working

# if proc takes very long to complete, the CPUs are free to use cycles for 
# other processes
stdout, stderr = await proc.communicate()

The process will start running as soon as the await asyncio.create_subprocess_exec(...) has completed. If it hasn't finished by the time you call await proc.communicate(), it will wait there in order to give you your output status. If it has finished, proc.communicate() will return immediately.

The gist here is similar to Terrels answer but I think Terrels answer appears to overcomplicate things.

See asyncio.create_subprocess_exec for more information.

How to run a stored procedure in oracle sql developer?

Try to execute the procedure like this,

var c refcursor;
execute pkg_name.get_user('14232', '15', 'TDWL', 'SA', 1, :c);
print c;

MyISAM versus InnoDB

For a load with more writes and reads, you will benefit from InnoDB. Because InnoDB provides row-locking rather than table-locking, your SELECTs can be concurrent, not just with each other but also with many INSERTs. However, unless you are intending to use SQL transactions, set the InnoDB commit flush to 2 (innodb_flush_log_at_trx_commit). This gives you back a lot of raw performance that you would otherwise lose when moving tables from MyISAM to InnoDB.

Also, consider adding replication. This gives you some read scaling and since you stated your reads don't have to be up-to-date, you can let the replication fall behind a little. Just be sure that it can catch up under anything but the heaviest traffic or it will always be behind and will never catch up. If you go this way, however, I strongly recommend you isolate reading from the slaves and replication lag management to your database handler. It is so much simpler if the application code does not know about this.

Finally, be aware of different table loads. You will not have the same read/write ratio on all tables. Some smaller tables with near 100% reads could afford to stay MyISAM. Likewise, if you have some tables that are near 100% write, you may benefit from INSERT DELAYED, but that is only supported in MyISAM (the DELAYED clause is ignored for an InnoDB table).

But benchmark to be sure.

Angular bootstrap datepicker date format does not format ng-model value

Finally I got work around to the above problem. angular-strap has exactly the same feature that I am expecting. Just by applying date-format="MM/dd/yyyy" date-type="string" I got my expected behavior of updating ng-model in given format.

<div class="bs-example" style="padding-bottom: 24px;" append-source>
    <form name="datepickerForm" class="form-inline" role="form">
      <!-- Basic example -->
      <div class="form-group" ng-class="{'has-error': datepickerForm.date.$invalid}">
        <label class="control-label"><i class="fa fa-calendar"></i> Date <small>(as date)</small></label>
        <input type="text"  autoclose="true"  class="form-control" ng-model="selectedDate" name="date" date-format="MM/dd/yyyy" date-type="string" bs-datepicker>
      </div>
      <hr>
      {{selectedDate}}
     </form>
</div>

here is working plunk link

How to wait for 2 seconds?

The documentation for WAITFOR() doesn't explicitly lay out the required string format.

This will wait for 2 seconds:

WAITFOR DELAY '00:00:02';

The format is hh:mi:ss.mmm.

How to convert list data into json in java

Try like below with Gson Library.

Earlier Conversion List format were:

[Product [Id=1, City=Bengalore, Category=TV, Brand=Samsung, Name=Samsung LED, Type=LED, Size=32 inches, Price=33500.5, Stock=17.0], Product [Id=2, City=Bengalore, Category=TV, Brand=Samsung, Name=Samsung LED, Type=LED, Size=42 inches, Price=41850.0, Stock=9.0]]

and here the conversion source begins.

//** Note I have created the method toString() in Product class.

//Creating and initializing a java.util.List of Product objects
List<Product> productList = (List<Product>)productRepository.findAll();

//Creating a blank List of Gson library JsonObject
List<JsonObject> entities = new ArrayList<JsonObject>();

//Simply printing productList size
System.out.println("Size of productList is : " + productList.size());

//Creating a Iterator for productList
Iterator<Product> iterator = productList.iterator();

//Run while loop till Product Object exists.
while(iterator.hasNext()){

    //Creating a fresh Gson Object
    Gson gs = new Gson();

    //Converting our Product Object to JsonElement 
    //Object by passing the Product Object String value (iterator.next())
    JsonElement element = gs.fromJson (gs.toJson(iterator.next()), JsonElement.class);

    //Creating JsonObject from JsonElement
    JsonObject jsonObject = element.getAsJsonObject();

    //Collecting the JsonObject to List
    entities.add(jsonObject);

}

//Do what you want to do with Array of JsonObject
System.out.println(entities);

Converted Json Result is :

[{"Id":1,"City":"Bengalore","Category":"TV","Brand":"Samsung","Name":"Samsung LED","Type":"LED","Size":"32 inches","Price":33500.5,"Stock":17.0}, {"Id":2,"City":"Bengalore","Category":"TV","Brand":"Samsung","Name":"Samsung LED","Type":"LED","Size":"42 inches","Price":41850.0,"Stock":9.0}]

Hope this would help many guys!

How to select first child with jQuery?

Hi we can use default method "first" in jQuery

Here some examples:

When you want to add class for first div

  $('.alldivs div').first().addClass('active');

When you want to change the remove the "onediv" class and add only to first child

   $('.alldivs div').removeClass('onediv').first().addClass('onediv');

How to get rid of blank pages in PDF exported from SSRS

If the pages are blank coming from SSRS, you need to tweak your report layout. This will be far more efficient than running the output through and post process to repair the side effects of a layout problem.

SSRS is very finicky when it comes to pushing the boundaries of the margins. It is easy to accidentally widen/lengthen the report just by adjusting text box or other control on the report. Check the width and height property of the report surface carefully and squeeze them as much as possible. Watch out for large headers and footers.

Array.push() if does not exist?

I know this is a very old question, but if you're using ES6 you can use a very small version:

[1,2,3].filter(f => f !== 3).concat([3])

Very easy, at first add a filter which removes the item - if it already exists, and then add it via a concat.

Here is a more realistic example:

const myArray = ['hello', 'world']
const newArrayItem

myArray.filter(f => f !== newArrayItem).concat([newArrayItem])

If you're array contains objects you could adapt the filter function like this:

someArray.filter(f => f.some(s => s.id === myId)).concat([{ id: myId }])

Importing images from a directory (Python) to list or dictionary

I'd start by using glob:

from PIL import Image
import glob
image_list = []
for filename in glob.glob('yourpath/*.gif'): #assuming gif
    im=Image.open(filename)
    image_list.append(im)

then do what you need to do with your list of images (image_list).

.NET NewtonSoft JSON deserialize map to a different property name

Expanding Rentering.com's answer, in scenarios where a whole graph of many types is to be taken care of, and you're looking for a strongly typed solution, this class can help, see usage (fluent) below. It operates as either a black-list or white-list per type. A type cannot be both (Gist - also contains global ignore list).

public class PropertyFilterResolver : DefaultContractResolver
{
  const string _Err = "A type can be either in the include list or the ignore list.";
  Dictionary<Type, IEnumerable<string>> _IgnorePropertiesMap = new Dictionary<Type, IEnumerable<string>>();
  Dictionary<Type, IEnumerable<string>> _IncludePropertiesMap = new Dictionary<Type, IEnumerable<string>>();
  public PropertyFilterResolver SetIgnoredProperties<T>(params Expression<Func<T, object>>[] propertyAccessors)
  {
    if (propertyAccessors == null) return this;

    if (_IncludePropertiesMap.ContainsKey(typeof(T))) throw new ArgumentException(_Err);

    var properties = propertyAccessors.Select(GetPropertyName);
    _IgnorePropertiesMap[typeof(T)] = properties.ToArray();
    return this;
  }

  public PropertyFilterResolver SetIncludedProperties<T>(params Expression<Func<T, object>>[] propertyAccessors)
  {
    if (propertyAccessors == null)
      return this;

    if (_IgnorePropertiesMap.ContainsKey(typeof(T))) throw new ArgumentException(_Err);

    var properties = propertyAccessors.Select(GetPropertyName);
    _IncludePropertiesMap[typeof(T)] = properties.ToArray();
    return this;
  }

  protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
  {
    var properties = base.CreateProperties(type, memberSerialization);

    var isIgnoreList = _IgnorePropertiesMap.TryGetValue(type, out IEnumerable<string> map);
    if (!isIgnoreList && !_IncludePropertiesMap.TryGetValue(type, out map))
      return properties;

    Func<JsonProperty, bool> predicate = jp => map.Contains(jp.PropertyName) == !isIgnoreList;
    return properties.Where(predicate).ToArray();
  }

  string GetPropertyName<TSource, TProperty>(
  Expression<Func<TSource, TProperty>> propertyLambda)
  {
    if (!(propertyLambda.Body is MemberExpression member))
      throw new ArgumentException($"Expression '{propertyLambda}' refers to a method, not a property.");

    if (!(member.Member is PropertyInfo propInfo))
      throw new ArgumentException($"Expression '{propertyLambda}' refers to a field, not a property.");

    var type = typeof(TSource);
    if (!type.GetTypeInfo().IsAssignableFrom(propInfo.DeclaringType.GetTypeInfo()))
      throw new ArgumentException($"Expresion '{propertyLambda}' refers to a property that is not from type '{type}'.");

    return propInfo.Name;
  }
}

Usage:

var resolver = new PropertyFilterResolver()
  .SetIncludedProperties<User>(
    u => u.Id, 
    u => u.UnitId)
  .SetIgnoredProperties<Person>(
    r => r.Responders)
  .SetIncludedProperties<Blog>(
    b => b.Id)
  .Ignore(nameof(IChangeTracking.IsChanged)); //see gist

How can I use a reportviewer control in an asp.net mvc 3 razor view?

This is a simple task. You can follow the following steps.

  1. Create a folder in your solution and name it Reports.
  2. Add an ASP.Net web form and name it ReportView.aspx
  3. Create a Class ReportData and add it to the Reports folder. Add the following code to the Class.

    public class ReportData  
    {  
        public ReportData()  
        {  
            this.ReportParameters = new List<Parameter>();  
            this.DataParameters = new List<Parameter>();  
        }
    
        public bool IsLocal { get; set; }
        public string ReportName { get; set; }
        public List<Parameter> ReportParameters { get; set; }
        public List<Parameter> DataParameters { get; set; }
    }
    
    public class Parameter  
    {  
        public string ParameterName { get; set; }  
        public string Value { get; set; }  
    }
    
  4. Add another Class and name it ReportBasePage.cs. Add the following code in this Class.

    public class ReportBasePage : System.Web.UI.Page
    {
        protected ReportData ReportDataObj { get; set; }
    
        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);
            if (HttpContext.Current != null)
                if (HttpContext.Current.Session["ReportData"] != null)
                {
                    ReportDataObj = HttpContext.Current.Session["ReportData"] as ReportData;
                    return;
                }
            ReportDataObj = new ReportData();
            CaptureRouteData(Page.Request);
        }
    
    
        private void CaptureRouteData(HttpRequest request)
        {
            var mode = (request.QueryString["rptmode"] + "").Trim();
            ReportDataObj.IsLocal = mode == "local" ? true : false;
            ReportDataObj.ReportName = request.QueryString["reportname"] + "";
            string dquerystr = request.QueryString["parameters"] + "";
            if (!String.IsNullOrEmpty(dquerystr.Trim()))
            {
                var param1 = dquerystr.Split(',');
                foreach (string pm in param1)
                {
                    var rp = new Parameter();
                    var kd = pm.Split('=');
                    if (kd[0].Substring(0, 2) == "rp")
                    {
                        rp.ParameterName = kd[0].Replace("rp", "");
                        if (kd.Length > 1) rp.Value = kd[1];
                        ReportDataObj.ReportParameters.Add(rp);
                    }
                    else if (kd[0].Substring(0, 2) == "dp")
                    {
                        rp.ParameterName = kd[0].Replace("dp", "");
                        if (kd.Length > 1) rp.Value = kd[1];
                        ReportDataObj.DataParameters.Add(rp);
                    }
                }
            }
        }
    }
    
  5. Add ScriptManager to the ReportView.aspx page. Now add a Report Viewer to the page. In report viewer set the property AsyncRendering="false". The code is given below.

        <rsweb:ReportViewer ID="ReportViewerRSFReports" runat="server" AsyncRendering="false"
            Width="1271px" Height="1000px" >
        </rsweb:ReportViewer>
    
  6. Add two NameSpace in ReportView.aspx.cs

    using Microsoft.Reporting.WebForms;
    using System.IO;
    
  7. Change the System.Web.UI.Page to ReportBasePage. Just replace your code using the following.

    public partial class ReportView : ReportBasePage
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                RenderReportModels(this.ReportDataObj);
            }
        }
    
        private void RenderReportModels(ReportData reportData)
        {
            // This is the Data Access Layer from which a method is called to fill data to the list.
            RASolarERPData dal = new RASolarERPData();
            List<ClosingInventoryValuation> objClosingInventory = new List<ClosingInventoryValuation>();
    
            // Reset report properties.
            ReportViewerRSFReports.Height = Unit.Parse("100%");
            ReportViewerRSFReports.Width = Unit.Parse("100%");
            ReportViewerRSFReports.CssClass = "table";
    
            // Clear out any previous datasources.
            this.ReportViewerRSFReports.LocalReport.DataSources.Clear();
    
            // Set report mode for local processing.
            ReportViewerRSFReports.ProcessingMode = ProcessingMode.Local;
    
            // Validate report source.
            var rptPath = Server.MapPath(@"./Report/" + reportData.ReportName +".rdlc");
    
            //@"E:\RSFERP_SourceCode\RASolarERP\RASolarERP\Reports\Report\" + reportData.ReportName + ".rdlc";
            //Server.MapPath(@"./Report/ClosingInventory.rdlc");
    
            if (!File.Exists(rptPath))
                return;
    
            // Set report path.
            this.ReportViewerRSFReports.LocalReport.ReportPath = rptPath;
    
            // Set report parameters.
            var rpPms = ReportViewerRSFReports.LocalReport.GetParameters();
            foreach (var rpm in rpPms)
            {
                var p = reportData.ReportParameters.SingleOrDefault(o => o.ParameterName.ToLower() == rpm.Name.ToLower());
                if (p != null)
                {
                    ReportParameter rp = new ReportParameter(rpm.Name, p.Value);
                    ReportViewerRSFReports.LocalReport.SetParameters(rp);
                }
            }
    
            //Set data paramater for report SP execution
            objClosingInventory = dal.ClosingInventoryReport(this.ReportDataObj.DataParameters[0].Value);
    
            // Load the dataSource.
            var dsmems = ReportViewerRSFReports.LocalReport.GetDataSourceNames();
            ReportViewerRSFReports.LocalReport.DataSources.Add(new ReportDataSource(dsmems[0], objClosingInventory));
    
            // Refresh the ReportViewer.
            ReportViewerRSFReports.LocalReport.Refresh();
        }
    }
    
  8. Add a Folder to the Reports Folder and name it Report. Now add a RDLC report to the Reports/Report folder and name it ClosingInventory.rdlc.

  9. Now add a Controller and name it ReportController. In the controller add the following action method.

    public ActionResult ReportViewer()
        {                
            ViewData["reportUrl"] = "../Reports/View/local/ClosingInventory/";
    
            return View();
        }
    
  10. Add a view page click on the ReportViewer Controller. Name the view page ReportViewer.cshtml. Add the following code to the view page.

    @using (Html.BeginForm("Login"))
     { 
           @Html.DropDownList("ddlYearMonthFormat", new SelectList(ViewBag.YearMonthFormat, "YearMonthValue",
     "YearMonthName"), new { @class = "DropDown" })
    
    Stock In Transit: @Html.TextBox("txtStockInTransit", "", new { @class = "LogInTextBox" })
    
    <input type="submit" onclick="return ReportValidationCheck();" name="ShowReport"
                     value="Show Report" />
    
    }
    
  11. Add an Iframe. Set the property of the Iframe as follows

    frameborder="0"  width="1000"; height="1000"; style="overflow:hidden;"
    scrolling="no"
    
  12. Add Following JavaScript to the viewer.

    function ReportValidationCheck() {
    
        var url = $('#hdUrl').val();
        var yearmonth = $('#ddlYearMonthFormat').val();      
        var stockInTransit = $('#txtStockInTransit').val()
    
        if (stockInTransit == "") {
            stockInTransit = 0;
        }
    
        if (yearmonth == "0") {
            alert("Please Select Month Correctly.");
        }
        else {
    
            //url = url + "dpSpYearMonth=" + yearmonth + ",rpYearMonth=" + yearmonth + ",rpStockInTransit=" + stockInTransit;
    
            url = "../Reports/ReportView.aspx?rptmode=local&reportname=ClosingInventory&parameters=dpSpYearMonth=" + yearmonth + ",rpYearMonth=" + yearmonth + ",rpStockInTransit=" + stockInTransit;
    
            var myframe = document.getElementById("ifrmReportViewer");
            if (myframe !== null) {
                if (myframe.src) {
                    myframe.src = url;
                }
                else if (myframe.contentWindow !== null && myframe.contentWindow.location !== null) {
                    myframe.contentWindow.location = url;
                }
                else { myframe.setAttribute('src', url); }
            }
        }
    
        return false;
    }
    
  13. Web.config file add the following key to the appSettings section

    add key="UnobtrusiveJavaScriptEnabled" value="true"
    
  14. In system.web handlers Section add the following key

    add verb="*" path="Reserved.ReportViewerWebControl.axd" type = "Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
    
  15. Change your data source to your own. This solution is very simple and I think every one will enjoy it.

How to get JSON from webpage into Python script

I have found this to be the easiest and most efficient way to get JSON from a webpage when using Python 3:

import json,urllib.request
data = urllib.request.urlopen("https://api.github.com/users?since=100").read()
output = json.loads(data)
print (output)

Datatables warning(table id = 'example'): cannot reinitialise data table

When searching this topic I found the solution elsewhere but adding the answer here since I had the same problem as above together with the text "Uncaught TypeError: Cannot set property '_DT_CellIndex' of undefined". Cause was due to having one to many tags in the table body.

How can I retrieve a table from stored procedure to a datatable?

Set the CommandText as well, and call Fill on the SqlAdapter to retrieve the results in a DataSet:

var con = new SqlConnection();
con.ConnectionString = "connection string";
var com = new SqlCommand();
com.Connection = con;
com.CommandType = CommandType.StoredProcedure;
com.CommandText = "sp_returnTable";
var adapt = new SqlDataAdapter();
adapt.SelectCommand = com;
var dataset = new DataSet();
adapt.Fill(dataset);

(Example is using parameterless constructors for clarity; can be shortened by using other constructors.)

Has Facebook sharer.php changed to no longer accept detailed parameters?

I review your url in use:

https://www.facebook.com/sharer/sharer.php?s=100&p[title]=EXAMPLE&p[summary]=EXAMPLE&p[url]=EXAMPLE&p[images][0]=EXAMPLE

and see this differences:

  1. The sharer URL not is same.
  2. The strings are in different order. ( Do not know if this affects ).

I use this URL string:

http://www.facebook.com/sharer.php?s=100&p[url]=http://www.example.com/&p[images][0]=/images/image.jpg&p[title]=Title&p[summary]=Summary

In the "title" and "summary" section, I use the php function urlencode(); like this:

<?php echo urlencode($detail->title); ?>

And working fine for me.

SQL Left Join first match only

Depending on the nature of the duplicate rows, it looks like all you want is to have case-sensitivity on those columns. Setting the collation on these columns should be what you're after:

SELECT DISTINCT p.IDNO COLLATE SQL_Latin1_General_CP1_CI_AS, p.FirstName COLLATE SQL_Latin1_General_CP1_CI_AS, p.LastName COLLATE SQL_Latin1_General_CP1_CI_AS
FROM people P

http://msdn.microsoft.com/en-us/library/ms184391.aspx

Removing duplicate rows from table in Oracle

5. solution

delete from emp where rowid in 
    (
      select  rid from
       (
         select rowid rid,rank() over (partition by emp_id order by rowid)rn from emp     
       )
     where rn > 1
    );

why should I make a copy of a data frame in pandas

Assumed you have data frame as below

df1
     A    B    C    D
4 -1.0 -1.0 -1.0 -1.0
5 -1.0 -1.0 -1.0 -1.0
6 -1.0 -1.0 -1.0 -1.0
6 -1.0 -1.0 -1.0 -1.0

When you would like create another df2 which is identical to df1, without copy

df2=df1
df2
     A    B    C    D
4 -1.0 -1.0 -1.0 -1.0
5 -1.0 -1.0 -1.0 -1.0
6 -1.0 -1.0 -1.0 -1.0
6 -1.0 -1.0 -1.0 -1.0

And would like modify the df2 value only as below

df2.iloc[0,0]='changed'

df2
         A    B    C    D
4  changed -1.0 -1.0 -1.0
5       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0

At the same time the df1 is changed as well

df1
         A    B    C    D
4  changed -1.0 -1.0 -1.0
5       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0

Since two df as same object, we can check it by using the id

id(df1)
140367679979600
id(df2)
140367679979600

So they as same object and one change another one will pass the same value as well.


If we add the copy, and now df1 and df2 are considered as different object, if we do the same change to one of them the other will not change.

df2=df1.copy()
id(df1)
140367679979600
id(df2)
140367674641232

df1.iloc[0,0]='changedback'
df2
         A    B    C    D
4  changed -1.0 -1.0 -1.0
5       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0
6       -1 -1.0 -1.0 -1.0

Good to mention, when you subset the original dataframe, it is safe to add the copy as well in order to avoid the SettingWithCopyWarning

Stick button to right side of div

Another solution: change margins. Depending on the siblings of the button, display should be modified.

button {
    display:      block;
    margin-left:  auto;
    margin-right: 0;
}

How can I uninstall Ruby on ubuntu?

Here is what sudo apt-get purge ruby* removed relating to GRUB for me:

grub-pc 
grub-gfxpayload-lists
grub2-common
grub-pc-bin 
grub-common 

When to use async false and async true in ajax function in jquery

It is best practice to go asynchronous if you can do several things in parallel (no inter-dependencies). If you need it to complete to continue loading the next thing you could use synchronous, but note that this option is deprecated to avoid abuse of sync:

jQuery.ajax() method's async option deprecated, what now?

Getting HTTP headers with Node.js

Try to look at http.get and response headers.

var http = require("http");

var options = {
  host: 'stackoverflow.com',
  port: 80,
  path: '/'
};

http.get(options, function(res) {
  console.log("Got response: " + res.statusCode);

  for(var item in res.headers) {
    console.log(item + ": " + res.headers[item]);
  }
}).on('error', function(e) {
  console.log("Got error: " + e.message);
});

Adding 'serial' to existing column in Postgres

Look at the following commands (especially the commented block).

DROP TABLE foo;
DROP TABLE bar;

CREATE TABLE foo (a int, b text);
CREATE TABLE bar (a serial, b text);

INSERT INTO foo (a, b) SELECT i, 'foo ' || i::text FROM generate_series(1, 5) i;
INSERT INTO bar (b) SELECT 'bar ' || i::text FROM generate_series(1, 5) i;

-- blocks of commands to turn foo into bar
CREATE SEQUENCE foo_a_seq;
ALTER TABLE foo ALTER COLUMN a SET DEFAULT nextval('foo_a_seq');
ALTER TABLE foo ALTER COLUMN a SET NOT NULL;
ALTER SEQUENCE foo_a_seq OWNED BY foo.a;    -- 8.2 or later

SELECT MAX(a) FROM foo;
SELECT setval('foo_a_seq', 5);  -- replace 5 by SELECT MAX result

INSERT INTO foo (b) VALUES('teste');
INSERT INTO bar (b) VALUES('teste');

SELECT * FROM foo;
SELECT * FROM bar;

Open the terminal in visual studio?

Visual Studio 2019 update:

Now vs has built-in terminal

TerminalSS

View > Terminal (Ctrl+")

To change default terminal

Tools > Options - Terminal > Set As Default

enter image description here


Before Visual Studio 2019

From comments best answer is from @Hans Passant

  1. Add an external tool.

Tools > External Tools > Add

Title: Terminal (or name it yourself)

Command=cmd.exe Or Command=powershell.exe

Arguments= /k

Initial Directory=$(ProjectDir)

  1. Tools > Terminal (or whatever you put in title)

  2. Enjoy!

Twitter Bootstrap modal on mobile devices

Albeit this question is quite old, some people still may stumble upon it when looking for solution to improve UX of modals on mobile phones.

I've made a lib to improve Bootrsrap modals' behavior on phones.

Bootstrap 3: https://github.com/keaukraine/bootstrap-fs-modal

Bootstrap 4: https://github.com/keaukraine/bootstrap4-fs-modal

Best practices for API versioning?

Versioning your REST API is analogous to the versioning of any other API. Minor changes can be done in place, major changes might require a whole new API. The easiest for you is to start from scratch every time, which is when putting the version in the URL makes most sense. If you want to make life easier for the client you try to maintain backwards compatibility, which you can do with deprecation (permanent redirect), resources in several versions etc. This is more fiddly and requires more effort. But it's also what REST encourages in "Cool URIs don't change".

In the end it's just like any other API design. Weigh effort against client convenience. Consider adopting semantic versioning for your API, which makes it clear for your clients how backwards compatible your new version is.

Convert Uppercase Letter to Lowercase and First Uppercase in Sentence using CSS

convert element's textContent to lowercase with JS..

el.textContent = el.textContent.toLowerCase();

then just use css..

text-transform: capitalize;

Copy / Put text on the clipboard with FireFox, Safari and Chrome

Clipboard API is designed to supersede document.execCommand. Safari is still working on support so you should provide a fallback until spec settles and Safari finishes implementation.

_x000D_
_x000D_
const permalink = document.querySelector('[rel="bookmark"]');_x000D_
const output = document.querySelector('output');_x000D_
permalink.onclick = evt => {_x000D_
  evt.preventDefault();_x000D_
  window.navigator.clipboard.writeText(_x000D_
    permalink.href_x000D_
  ).then(() => {_x000D_
    output.textContent = 'Copied';_x000D_
  }, () => {_x000D_
    output.textContent = 'Not copied';_x000D_
  });_x000D_
};
_x000D_
<a href="https://stackoverflow.com/questions/127040/" rel="bookmark">Permalink</a>_x000D_
<output></output>
_x000D_
_x000D_
_x000D_

For security reasons clipboard Permissions may be necessary to read and write from the clipboard. If the snippet doesn't work on SO give it a shot on localhost or an otherwise trusted domain.

How do you use the "WITH" clause in MySQL?

I followed the link shared by lisachenko and found another link to this blog: http://guilhembichot.blogspot.co.uk/2013/11/with-recursive-and-mysql.html

The post lays out ways of emulating the 2 uses of SQL WITH. Really good explanation on how these work to do a similar query as SQL WITH.

1) Use WITH so you don't have to perform the same sub query multiple times

CREATE VIEW D AS (SELECT YEAR, SUM(SALES) AS S FROM T1 GROUP BY YEAR);
SELECT D1.YEAR, (CASE WHEN D1.S>D2.S THEN 'INCREASE' ELSE 'DECREASE' END) AS TREND
FROM
 D AS D1,
 D AS D2
WHERE D1.YEAR = D2.YEAR-1;
DROP VIEW D;

2) Recursive queries can be done with a stored procedure that makes the call similar to a recursive with query.

CALL WITH_EMULATOR(
"EMPLOYEES_EXTENDED",
"
  SELECT ID, NAME, MANAGER_ID, 0 AS REPORTS
  FROM EMPLOYEES
  WHERE ID NOT IN (SELECT MANAGER_ID FROM EMPLOYEES WHERE MANAGER_ID IS NOT NULL)
",
"
  SELECT M.ID, M.NAME, M.MANAGER_ID, SUM(1+E.REPORTS) AS REPORTS
  FROM EMPLOYEES M JOIN EMPLOYEES_EXTENDED E ON M.ID=E.MANAGER_ID
  GROUP BY M.ID, M.NAME, M.MANAGER_ID
",
"SELECT * FROM EMPLOYEES_EXTENDED",
0,
""
);

And this is the code or the stored procedure

# Usage: the standard syntax:
#   WITH RECURSIVE recursive_table AS
#    (initial_SELECT
#     UNION ALL
#     recursive_SELECT)
#   final_SELECT;
# should be translated by you to 
# CALL WITH_EMULATOR(recursive_table, initial_SELECT, recursive_SELECT,
#                    final_SELECT, 0, "").

# ALGORITHM:
# 1) we have an initial table T0 (actual name is an argument
# "recursive_table"), we fill it with result of initial_SELECT.
# 2) We have a union table U, initially empty.
# 3) Loop:
#   add rows of T0 to U,
#   run recursive_SELECT based on T0 and put result into table T1,
#   if T1 is empty
#      then leave loop,
#      else swap T0 and T1 (renaming) and empty T1
# 4) Drop T0, T1
# 5) Rename U to T0
# 6) run final select, send relult to client

# This is for *one* recursive table.
# It would be possible to write a SP creating multiple recursive tables.

delimiter |

CREATE PROCEDURE WITH_EMULATOR(
recursive_table varchar(100), # name of recursive table
initial_SELECT varchar(65530), # seed a.k.a. anchor
recursive_SELECT varchar(65530), # recursive member
final_SELECT varchar(65530), # final SELECT on UNION result
max_recursion int unsigned, # safety against infinite loop, use 0 for default
create_table_options varchar(65530) # you can add CREATE-TABLE-time options
# to your recursive_table, to speed up initial/recursive/final SELECTs; example:
# "(KEY(some_column)) ENGINE=MEMORY"
)

BEGIN
  declare new_rows int unsigned;
  declare show_progress int default 0; # set to 1 to trace/debug execution
  declare recursive_table_next varchar(120);
  declare recursive_table_union varchar(120);
  declare recursive_table_tmp varchar(120);
  set recursive_table_next  = concat(recursive_table, "_next");
  set recursive_table_union = concat(recursive_table, "_union");
  set recursive_table_tmp   = concat(recursive_table, "_tmp"); 
  # Cleanup any previous failed runs
  SET @str =
    CONCAT("DROP TEMPORARY TABLE IF EXISTS ", recursive_table, ",",
    recursive_table_next, ",", recursive_table_union,
    ",", recursive_table_tmp);
  PREPARE stmt FROM @str;
  EXECUTE stmt; 
 # If you need to reference recursive_table more than
  # once in recursive_SELECT, remove the TEMPORARY word.
  SET @str = # create and fill T0
    CONCAT("CREATE TEMPORARY TABLE ", recursive_table, " ",
    create_table_options, " AS ", initial_SELECT);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  SET @str = # create U
    CONCAT("CREATE TEMPORARY TABLE ", recursive_table_union, " LIKE ", recursive_table);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  SET @str = # create T1
    CONCAT("CREATE TEMPORARY TABLE ", recursive_table_next, " LIKE ", recursive_table);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  if max_recursion = 0 then
    set max_recursion = 100; # a default to protect the innocent
  end if;
  recursion: repeat
    # add T0 to U (this is always UNION ALL)
    SET @str =
      CONCAT("INSERT INTO ", recursive_table_union, " SELECT * FROM ", recursive_table);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
    # we are done if max depth reached
    set max_recursion = max_recursion - 1;
    if not max_recursion then
      if show_progress then
        select concat("max recursion exceeded");
      end if;
      leave recursion;
    end if;
    # fill T1 by applying the recursive SELECT on T0
    SET @str =
      CONCAT("INSERT INTO ", recursive_table_next, " ", recursive_SELECT);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
    # we are done if no rows in T1
    select row_count() into new_rows;
    if show_progress then
      select concat(new_rows, " new rows found");
    end if;
    if not new_rows then
      leave recursion;
    end if;
    # Prepare next iteration:
    # T1 becomes T0, to be the source of next run of recursive_SELECT,
    # T0 is recycled to be T1.
    SET @str =
      CONCAT("ALTER TABLE ", recursive_table, " RENAME ", recursive_table_tmp);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
    # we use ALTER TABLE RENAME because RENAME TABLE does not support temp tables
    SET @str =
      CONCAT("ALTER TABLE ", recursive_table_next, " RENAME ", recursive_table);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
    SET @str =
      CONCAT("ALTER TABLE ", recursive_table_tmp, " RENAME ", recursive_table_next);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
    # empty T1
    SET @str =
      CONCAT("TRUNCATE TABLE ", recursive_table_next);
    PREPARE stmt FROM @str;
    EXECUTE stmt;
  until 0 end repeat;
  # eliminate T0 and T1
  SET @str =
    CONCAT("DROP TEMPORARY TABLE ", recursive_table_next, ", ", recursive_table);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  # Final (output) SELECT uses recursive_table name
  SET @str =
    CONCAT("ALTER TABLE ", recursive_table_union, " RENAME ", recursive_table);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  # Run final SELECT on UNION
  SET @str = final_SELECT;
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  # No temporary tables may survive:
  SET @str =
    CONCAT("DROP TEMPORARY TABLE ", recursive_table);
  PREPARE stmt FROM @str;
  EXECUTE stmt;
  # We are done :-)
END|

delimiter ;

Difference Between Select and SelectMany

The SelectMany() method is used to flatten a sequence in which each of the elements of the sequence is a separate.

I have class user same like this

class User
    {
        public string UserName { get; set; }
        public List<string> Roles { get; set; }
    }

main:

var users = new List<User>
            {
                new User { UserName = "Reza" , Roles = new List<string>{"Superadmin" } },
                new User { UserName = "Amin" , Roles = new List<string>{"Guest","Reseption" } },
                new User { UserName = "Nima" , Roles = new List<string>{"Nurse","Guest" } },
            };

var query = users.SelectMany(user => user.Roles, (user, role) => new { user.UserName, role });

foreach (var obj in query)
{
    Console.WriteLine(obj);
}
//output

//{ UserName = Reza, role = Superadmin }
//{ UserName = Amin, role = Guest }
//{ UserName = Amin, role = Reseption }
//{ UserName = Nima, role = Nurse }
//{ UserName = Nima, role = Guest }

You can use operations on any item of sequence

int[][] numbers = {
                new[] {1, 2, 3},
                new[] {4},
                new[] {5, 6 , 6 , 2 , 7, 8},
                new[] {12, 14}
            };

IEnumerable<int> result = numbers
                .SelectMany(array => array.Distinct())
                .OrderBy(x => x);

//output

//{ 1, 2 , 2 , 3, 4, 5, 6, 7, 8, 12, 14 }
 List<List<int>> numbers = new List<List<int>> {
                new List<int> {1, 2, 3},
                new List<int> {12},
                new List<int> {5, 6, 5, 7},
                new List<int> {10, 10, 10, 12}
            };

 IEnumerable<int> result = numbers
                .SelectMany(list => list)
                .Distinct()
                .OrderBy(x=>x);

//output

// { 1, 2, 3, 5, 6, 7, 10, 12 }

Install a module using pip for specific python version

Python 2

sudo pip2 install johnbonjovi  

Python 3

sudo pip3 install johnbonjovi

Javascript loop through object array?

for (let key in data) {
    let value = data[key];
    for (i = 0; i < value.length; i++) {
      console.log(value[i].msgFrom);
      console.log(value[i].msgBody);
    }
  }

How to pass arguments to a Dockerfile?

You are looking for --build-arg and the ARG instruction. These are new as of Docker 1.9. Check out https://docs.docker.com/engine/reference/builder/#arg. This will allow you to add ARG arg to the Dockerfile and then build with docker build --build-arg arg=2.3 ..

Calling a parent window function from an iframe

With Firefox and Chrome you can use :

<a href="whatever" target="_parent" onclick="myfunction()">

If myfunction is present both in iframe and in parent, the parent one will be called.

Save bitmap to location

Here is the sample code for saving bitmap to file :

public static File savebitmap(Bitmap bmp) throws IOException {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    bmp.compress(Bitmap.CompressFormat.JPEG, 60, bytes);
    File f = new File(Environment.getExternalStorageDirectory()
            + File.separator + "testimage.jpg");
    f.createNewFile();
    FileOutputStream fo = new FileOutputStream(f);
    fo.write(bytes.toByteArray());
    fo.close();
    return f;
}

Now call this function to save the bitmap to internal memory.

File newfile = savebitmap(bitmap);

I hope it will help you. Happy codeing life.

Xcode process launch failed: Security

In iOS 9.2 they renamed the 'Profiles' to 'Device Management'

This is how you should do it now:

  1. Settings -> General -> Device Management
  2. Verify the app

How to get Toolbar from fragment?

In XML

 <androidx.appcompat.widget.Toolbar
  android:id="@+id/main_toolbar"
  android:layout_width="match_parent"
  android:layout_height="?attr/actionBarSize"
  app:layout_scrollFlags="scroll|enterAlways">
 </androidx.appcompat.widget.Toolbar>

Kotlin: In fragment.kt -> onCreateView()

setHasOptionsMenu(true)

val toolbar = view.findViewById<Toolbar>(R.id.main_toolbar)

(activity as? AppCompatActivity)?.setSupportActionBar(toolbar)

(activity as? AppCompatActivity)?.supportActionBar?.show()

-> onCreateOptionsMenu()

   override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
       inflater.inflate(R.menu.app_main_menu,menu)
       super.onCreateOptionsMenu(menu, inflater)
   }

->onOptionsItemSelected()

   override fun onOptionsItemSelected(item: MenuItem): Boolean {
        return when (item.itemId) {
             R.id.selected_id->{//to_do}
             else -> super.onOptionsItemSelected(item)
        }
    }

Java Round up Any Number

int RoundedUp = (int) Math.ceil(RandomReal);

This seemed to do the perfect job. Worked everytime.

What HTTP status response code should I use if the request is missing a required parameter?

Status 422 seems most appropiate based on the spec.

The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415(Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions. For example, this error condition may occur if an XML request body contains well-formed (i.e., syntactically correct), but semantically erroneous, XML instructions.

They state that malformed xml is an example of bad syntax (calling for a 400). A malformed query string seems analogous to this, so 400 doesn't seem appropriate for a well-formed query-string which is missing a param.

UPDATE @DavidV correctly points out that this spec is for WebDAV, not core HTTP. But some popular non-WebDAV APIs are using 422 anyway, for lack of a better status code (see this).

How do I copy an entire directory of files into an existing directory using Python?

i would assume fastest and simplest way would be have python call the system commands...

example..

import os
cmd = '<command line call>'
os.system(cmd)

Tar and gzip up the directory.... unzip and untar the directory in the desired place.

yah?

What is the simplest way to SSH using Python?

I have written Python bindings for libssh2. Libssh2 is a client-side library implementing the SSH2 protocol.

import socket
import libssh2

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('exmaple.com', 22))

session = libssh2.Session()
session.startup(sock)
session.userauth_password('john', '******')

channel = session.channel()
channel.execute('ls -l')

print channel.read(1024)

How to convert a String to JsonObject using gson library

JsonObject jsonObject = (JsonObject) new JsonParser().parse("YourJsonString");

Get random integer in range (x, y]?

Random generator = new Random(); 
int i = generator.nextInt(10) + 1;

Video streaming over websockets using JavaScript

Is WebSockets over TCP a fast enough protocol to stream a video of, say, 30fps?

Yes.. it is, take a look at this project. Websockets can easily handle HD videostreaming.. However, you should go for Adaptive Streaming. I explain here how you could implement it.

Currently we're working on a webbased instant messaging application with chat, filesharing and video/webcam support. With some bits and tricks we got streaming media through websockets (used HTML5 Media Capture to get the stream from our webcams).

You need to build a stream API and a Media Stream Transceiver to control the related media processing and transport.

MVVM Passing EventArgs As Command Parameter

I know this is a fairly old question, but I ran into the same problem today and wasn't too interested in referencing all of MVVMLight just so I can use event triggers with event args. I have used MVVMLight in the past and it's a great framework, but I just don't want to use it for my projects any more.

What I did to resolve this problem was create an ULTRA minimal, EXTREMELY adaptable custom trigger action that would allow me to bind to the command and provide an event args converter to pass on the args to the command's CanExecute and Execute functions. You don't want to pass the event args verbatim, as that would result in view layer types being sent to the view model layer (which should never happen in MVVM).

Here is the EventCommandExecuter class I came up with:

public class EventCommandExecuter : TriggerAction<DependencyObject>
{
    #region Constructors

    public EventCommandExecuter()
        : this(CultureInfo.CurrentCulture)
    {
    }

    public EventCommandExecuter(CultureInfo culture)
    {
        Culture = culture;
    }

    #endregion

    #region Properties

    #region Command

    public ICommand Command
    {
        get { return (ICommand)GetValue(CommandProperty); }
        set { SetValue(CommandProperty, value); }
    }

    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.Register("Command", typeof(ICommand), typeof(EventCommandExecuter), new PropertyMetadata(null));

    #endregion

    #region EventArgsConverterParameter

    public object EventArgsConverterParameter
    {
        get { return (object)GetValue(EventArgsConverterParameterProperty); }
        set { SetValue(EventArgsConverterParameterProperty, value); }
    }

    public static readonly DependencyProperty EventArgsConverterParameterProperty =
        DependencyProperty.Register("EventArgsConverterParameter", typeof(object), typeof(EventCommandExecuter), new PropertyMetadata(null));

    #endregion

    public IValueConverter EventArgsConverter { get; set; }

    public CultureInfo Culture { get; set; }

    #endregion

    protected override void Invoke(object parameter)
    {
        var cmd = Command;

        if (cmd != null)
        {
            var param = parameter;

            if (EventArgsConverter != null)
            {
                param = EventArgsConverter.Convert(parameter, typeof(object), EventArgsConverterParameter, CultureInfo.InvariantCulture);
            }

            if (cmd.CanExecute(param))
            {
                cmd.Execute(param);
            }
        }
    }
}

This class has two dependency properties, one to allow binding to your view model's command, the other allows you to bind the source of the event if you need it during event args conversion. You can also provide culture settings if you need to (they default to the current UI culture).

This class allows you to adapt the event args so that they may be consumed by your view model's command logic. However, if you want to just pass the event args on verbatim, simply don't specify an event args converter.

The simplest usage of this trigger action in XAML is as follows:

<i:Interaction.Triggers>
    <i:EventTrigger EventName="NameChanged">
        <cmd:EventCommandExecuter Command="{Binding Path=Update, Mode=OneTime}" EventArgsConverter="{x:Static c:NameChangedArgsToStringConverter.Default}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

If you needed access to the source of the event, you would bind to the owner of the event

<i:Interaction.Triggers>
    <i:EventTrigger EventName="NameChanged">
        <cmd:EventCommandExecuter 
            Command="{Binding Path=Update, Mode=OneTime}" 
            EventArgsConverter="{x:Static c:NameChangedArgsToStringConverter.Default}"
            EventArgsConverterParameter="{Binding ElementName=SomeEventSource, Mode=OneTime}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

(this assumes that the XAML node you're attaching the triggers to has been assigned x:Name="SomeEventSource"

This XAML relies on importing some required namespaces

xmlns:cmd="clr-namespace:MyProject.WPF.Commands"
xmlns:c="clr-namespace:MyProject.WPF.Converters"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

and creating an IValueConverter (called NameChangedArgsToStringConverter in this case) to handle the actual conversion logic. For basic converters I usually create a default static readonly converter instance, which I can then reference directly in XAML as I have done above.

The benefit of this solution is that you really only need to add a single class to any project to use the interaction framework much the same way that you would use it with InvokeCommandAction. Adding a single class (of about 75 lines) should be much more preferable to an entire library to accomplish identical results.

NOTE

this is somewhat similar to the answer from @adabyron but it uses event triggers instead of behaviours. This solution also provides an event args conversion ability, not that @adabyron's solution could not do this as well. I really don't have any good reason why I prefer triggers to behaviours, just a personal choice. IMO either strategy is a reasonable choice.

Disabling enter key for form

You can try something like this, if you use jQuery.

$("form").bind("keydown", function(e) {
   if (e.keyCode === 13) return false;
 });

That will wait for a keydown, if it is Enter, it will do nothing.

font-family is inherit. How to find out the font-family in chrome developer pane?

I think op wants to know what the font that is used on a webpage is, and hoped that info might be findable in the 'inspect' pane.

Try adding the Whatfont Chrome extension.

How npm start runs a server on port 8000

We have a react application and our development machines are both mac and pc. The start command doesn't work for PC so here is how we got around it:

"start": "PORT=3001 react-scripts start",
"start-pc": "set PORT=3001&& react-scripts start",

On my mac:

npm start

On my pc:

 npm run start-pc

CREATE DATABASE permission denied in database 'master' (EF code-first)

I'm going to add what I've had to do, as it is an amalgamation of the above. I'm using Code First, tried using 'create-database' but got the error in the title. Closed and re-opened (as Admin this time) - command not recognised but 'update-database' was so used that. Same error.

Here are the steps I took to resolve it:

1) Opened SQL Server Management Studio and created a database "Videos"

2) Opened Server Explorer in VS2013 (under 'View') and connected to the database.

3) Right clicked on the connection -> properties, and grabbed the connection string.

4) In the web.config I added the connection string

   <connectionStrings>
<add name="DefaultConnection"
  connectionString="Data Source=MyMachine;Initial Catalog=Videos;Integrated Security=True" providerName="System.Data.SqlClient"
  />
  </connectionStrings>

5) Where I set up the context, I need to reference DefaultConnection:

using System.Data.Entity;

namespace Videos.Models
{
public class VideoDb : DbContext
{
    public VideoDb()
        : base("name=DefaultConnection")
    {

    }

    public DbSet<Video> Videos { get; set; }
}
}

6) In Package Manager console run 'update-database' to create the table(s).

Remember you can use Seed() to insert values when creating, in Configuration.cs:

        protected override void Seed(Videos.Models.VideoDb context)
        {
        context.Videos.AddOrUpdate(v => v.Title,
            new Video() { Title = "MyTitle1", Length = 150 },
            new Video() { Title = "MyTitle2", Length = 270 }
            );

        context.SaveChanges();
        }

How do I declare an array variable in VBA?

The Array index only accepts a long value.

You declared iCounter as an integer. You should declare it as a long.

Android WebView progress bar

According to Md. Sajedul Karim answer I wrote a similar one.

webView = (WebView) view.findViewById(R.id.web);
progressBar = (ProgressBar) view.findViewById(R.id.progress);
webView.setWebChromeClient(new WebChromeClient());

setProgressBarVisibility(View.VISIBLE);
webView.setWebViewClient(new WebViewClient() {
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        super.onPageStarted(view, url, favicon);
        setProgressBarVisibility(View.VISIBLE);
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        setProgressBarVisibility(View.GONE);
    }

    @Override
    public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
        super.onReceivedError(view, request, error);
        Toast.makeText(getActivity(), "Cannot load page", Toast.LENGTH_SHORT).show();
        setProgressBarVisibility(View.GONE);
    }
});

webView.loadUrl(url);

private void setProgressBarVisibility(int visibility) {
    // If a user returns back, a NPE may occur if WebView is still loading a page and then tries to hide a ProgressBar.
    if (progressBar != null) {
        progressBar.setVisibility(visibility);
    }
}

Android runOnUiThread explanation

This should work for you

 public class MyActivity extends Activity {

    protected ProgressDialog mProgressDialog;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        populateTable();
    }

    private void populateTable() {
        mProgressDialog = ProgressDialog.show(this, "Please wait","Long operation starts...", true);
        new Thread() {
            @Override
            public void run() {

                doLongOperation();
                try {

                    // code runs in a thread
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            mProgressDialog.dismiss();
                        }
                    });
                } catch (final Exception ex) {
                    Log.i("---","Exception in thread");
                }
            }
        }.start();

    }

    /** fake operation for testing purpose */
    protected void doLongOperation() {
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
        }

    }
}

Accessing the logged-in user in a template

For symfony 2.6 and above we can use

{{ app.user.getFirstname() }}

as app.security global variable for Twig template has been deprecated and will be removed from 3.0

more info:

http://symfony.com/blog/new-in-symfony-2-6-security-component-improvements

and see the global variables in

http://symfony.com/doc/current/reference/twig_reference.html

adb command for getting ip address assigned by operator

Try:

adb shell ip addr show rmnet0

It will return something like that:

3: rmnet0: <UP,LOWER_UP> mtu 1500 qdisc htb state UNKNOWN qlen 1000
    link/[530]
    inet 172.22.1.100/29 scope global rmnet0
    inet6 fc01:abab:cdcd:efe0:8099:af3f:2af2:8bc/64 scope global dynamic
       valid_lft forever preferred_lft forever
    inet6 fe80::8099:af3f:2af2:8bc/64 scope link
       valid_lft forever preferred_lft forever 

This part is your IPV4 assigned by the operator

inet 172.22.1.100

This part is your IPV6 assigned by the operator

inet6 fc01:abab:cdcd:efe0:8099:af3f:2af2:8bc

How to use a BackgroundWorker?

I know this is a bit old, but in case another beginner is going through this, I'll share some code that covers a bit more of the basic operations, here is another example that also includes the option to cancel the process and also report to the user the status of the process. I'm going to add on top of the code given by Alex Aza in the solution above

public Form1()
{
    InitializeComponent();

    backgroundWorker1.DoWork += backgroundWorker1_DoWork;
    backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
    backgroundWorker1.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted;  //Tell the user how the process went
    backgroundWorker1.WorkerReportsProgress = true;
    backgroundWorker1.WorkerSupportsCancellation = true; //Allow for the process to be cancelled
}

//Start Process
private void button1_Click(object sender, EventArgs e)
{
    backgroundWorker1.RunWorkerAsync();
}

//Cancel Process
private void button2_Click(object sender, EventArgs e)
{
    //Check if background worker is doing anything and send a cancellation if it is
    if (backgroundWorker1.IsBusy)
    {
        backgroundWorker1.CancelAsync();
    }

}

private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
    for (int i = 0; i < 100; i++)
    {
        Thread.Sleep(1000);
        backgroundWorker1.ReportProgress(i);

        //Check if there is a request to cancel the process
        if (backgroundWorker1.CancellationPending)
        {
            e.Cancel = true;
            backgroundWorker1.ReportProgress(0);
            return;
        }
    }
    //If the process exits the loop, ensure that progress is set to 100%
    //Remember in the loop we set i < 100 so in theory the process will complete at 99%
    backgroundWorker1.ReportProgress(100);
}

private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
}

private void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e)
{
    if (e.Cancelled)
    {
         lblStatus.Text = "Process was cancelled";
    }
    else if (e.Error != null)
    {
         lblStatus.Text = "There was an error running the process. The thread aborted";
    }
    else
    {
       lblStatus.Text = "Process was completed";
    }
}

How do I hide an element on a click event anywhere outside of the element?

If I understand, you want to hide a div when you click anywhere but the div, and if you do click while over the div, then it should NOT close. You can do that with this code:

$(document).click(function() {
    alert("me");
});
$(".myDiv").click(function(e) {
    e.stopPropagation(); // This is the preferred method.
    return false;        // This should not be used unless you do not want
                         // any click events registering inside the div
});

This binds the click to the entire page, but if you click on the div in question, it will cancel the click event.

Clearing content of text file using C#

Another short version:

System.IO.File.WriteAllBytes(path, new byte[0]);

How to use Microsoft.Office.Interop.Excel on a machine without installed MS Office?

You can't use Microsoft.Office.Interop.Excel without having ms office installed.

Just search in google for some libraries, which allows to modify xls or xlsx:

Bash script processing limited number of commands in parallel

In fact, xargs can run commands in parallel for you. There is a special -P max_procs command-line option for that. See man xargs.

disable editing default value of text input

How about disabled=disabled:

<input id="price_from" value="price from " disabled="disabled">????????????

Problem is if you don't want user to edit them, why display them in input? You can hide them even if you want to submit a form. And to display information, just use other tag instead.

Find column whose name contains a specific string

Getting name and subsetting based on Start, Contains, and Ends:

# from: https://stackoverflow.com/questions/21285380/find-column-whose-name-contains-a-specific-string
# from: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.str.contains.html
# from: https://cmdlinetips.com/2019/04/how-to-select-columns-using-prefix-suffix-of-column-names-in-pandas/
# from: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.filter.html




import pandas as pd



data = {'spike_starts': [1,2,3], 'ends_spike_starts': [4,5,6], 'ends_spike': [7,8,9], 'not': [10,11,12]}
df = pd.DataFrame(data)



print("\n")
print("----------------------------------------")
colNames_contains = df.columns[df.columns.str.contains(pat = 'spike')].tolist() 
print("Contains")
print(colNames_contains)



print("\n")
print("----------------------------------------")
colNames_starts = df.columns[df.columns.str.contains(pat = '^spike')].tolist() 
print("Starts")
print(colNames_starts)



print("\n")
print("----------------------------------------")
colNames_ends = df.columns[df.columns.str.contains(pat = 'spike$')].tolist() 
print("Ends")
print(colNames_ends)



print("\n")
print("----------------------------------------")
df_subset_start = df.filter(regex='^spike',axis=1)
print("Starts")
print(df_subset_start)



print("\n")
print("----------------------------------------")
df_subset_contains = df.filter(regex='spike',axis=1)
print("Contains")
print(df_subset_contains)



print("\n")
print("----------------------------------------")
df_subset_ends = df.filter(regex='spike$',axis=1)
print("Ends")
print(df_subset_ends)

How do I export (and then import) a Subversion repository?

If you want to move the repository and keep history, you'll probably need filesystem access on both hosts. The simplest solution, if your backend is FSFS (the default on recent versions), is to make a filesystem copy of the entire repository folder.

If you have a Berkley DB backend, if you're not sure of what your backend is, or if you're changing SVN version numbers, you're going to want to use svnadmin to dump your old repository and load it into your new repository. Using svnadmin dump will give you a single file backup that you can copy to the new system. Then you can create the new (empty) repository and use svnadmin load, which will essentially replay all the commits along with its metadata (author, timestamp, etc).

You can read more about the dump/load process here:

http://svnbook.red-bean.com/en/1.8/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate

Also, if you do svnadmin load, make sure you use the --force-uuid option, or otherwise people are going to have problems switching to the new repository. Subversion uses a UUID to identify the repository internally, and it won't let you switch a working copy to a different repository.

If you don't have filesystem access, there may be other third party options out there (or you can write something) to help you migrate: essentially you'd have to use the svn log to replay each revision on the new repository, and then fix up the metadata afterwards. You'll need the pre-revprop-change and post-revprop-change hook scripts in place to do this, which sort of assumes filesystem access, so YMMV. Or, if you don't want to keep the history, you can use your working copy to import into the new repository. But hopefully this isn't the case.

Get Value of Row in Datatable c#

Dont use a foreach then. Use a 'for loop'. Your code is a bit messed up but you could do something like...

for (Int32 i = 0; i < dt_pattern.Rows.Count; i++)
{
    double yATmax = ToDouble(dt_pattern.Rows[i+1]["Ampl"].ToString()) + AT;
}

Note you would have to take into account during the last row there will be no 'i+1' so you will have to use an if statement to catch that.

How to get pip to work behind a proxy server

First Try to set proxy using the following command

SET HTTPS_PROXY=http://proxy.***.com:PORT#

Then Try using the command

pip install ModuleName

S3 Static Website Hosting Route All Paths to Index.html

It's tangential, but here's a tip for those using Rackt's React Router library with (HTML5) browser history who want to host on S3.

Suppose a user visits /foo/bear at your S3-hosted static web site. Given David's earlier suggestion, redirect rules will send them to /#/foo/bear. If your application's built using browser history, this won't do much good. However your application is loaded at this point and it can now manipulate history.

Including Rackt history in our project (see also Using Custom Histories from the React Router project), you can add a listener that's aware of hash history paths and replace the path as appropriate, as illustrated in this example:

import ReactDOM from 'react-dom';

/* Application-specific details. */
const route = {};

import { Router, useRouterHistory } from 'react-router';
import { createHistory } from 'history';

const history = useRouterHistory(createHistory)();

history.listen(function (location) {
  const path = (/#(\/.*)$/.exec(location.hash) || [])[1];
  if (path) history.replace(path);
});

ReactDOM.render(
  <Router history={history} routes={route}/>,
  document.body.appendChild(document.createElement('div'))
);

To recap:

  1. David's S3 redirect rule will direct /foo/bear to /#/foo/bear.
  2. Your application will load.
  3. The history listener will detect the #/foo/bear history notation.
  4. And replace history with the correct path.

Link tags will work as expected, as will all other browser history functions. The only downside I've noticed is the interstitial redirect that occurs on initial request.

This was inspired by a solution for AngularJS, and I suspect could be easily adapted to any application.

Loop through columns and add string lengths as new columns

With dplyr and stringr you can use mutate_all:

> df %>% mutate_all(funs(length = str_length(.)))

     col1     col2 col1_length col2_length
1     abc adf qqwe           3           8
2    abcd        d           4           1
3       a        e           1           1
4 abcdefg        f           7           1

Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?

I've occasionally found the following idiom useful:

a?.b?.c

can be rewritten as:

((a||{}).b||{}).c

This takes advantage of the fact that getting unknown attributes on an object returns undefined, rather than throwing an exception as it does on null or undefined, so we replace null and undefined with an empty object before navigating.

Remove all special characters from a string in R?

Convert the Special characters to apostrophe,

Data  <- gsub("[^0-9A-Za-z///' ]","'" , Data ,ignore.case = TRUE)

Below code it to remove extra ''' apostrophe

Data <- gsub("''","" , Data ,ignore.case = TRUE)

Use gsub(..) function for replacing the special character with apostrophe

How can I easily add storage to a VirtualBox machine with XP installed?

I found this nugget at the link following. It worked perfect for me and only took 5 seconds.

As of VirtualBox 4 they added support for expansion.

VBoxManage modifyhd filename.vdi --resize 46080

That will resize a virtual disk image to 45GB.

https://superuser.com/questions/172651/increasing-disk-space-on-virtualbox

Nodejs cannot find installed module on Windows

For me worked on Windows 10 npm config set prefix %AppData%\npm\node_modules

How to make <div> fill <td> height

Modify the background image of the <td> itself.

Or apply some css to the div:

.thatSetsABackgroundWithAnIcon{
    height:100%;
}

What can I use for good quality code coverage for C#/.NET?

C# Test Coverage Tool has very low overhead, handles huge systems of files, intuitive GUI showing coverage on specific files, and generated report with coverage breakdown at method, class, and package levels.

Remove all elements contained in another array

Proper way to remove all elements contained in another array is to make source array same object by remove only elements:

Array.prototype.removeContained = function(array) {
  var i, results;
  i = this.length;
  results = [];
  while (i--) {
    if (array.indexOf(this[i]) !== -1) {
      results.push(this.splice(i, 1));
    }
  }
  return results;
};

Or CoffeeScript equivalent:

Array.prototype.removeContained = (array) ->
  i = @length
  @splice i, 1 while i-- when array.indexOf(@[i]) isnt -1

Testing inside chrome dev tools:

19:33:04.447 a=1
19:33:06.354 b=2
19:33:07.615 c=3
19:33:09.981 arr = [a,b,c]
19:33:16.460 arr1 = arr

19:33:20.317 arr1 === arr
19:33:20.331 true

19:33:43.592 arr.removeContained([a,c])
19:33:52.433 arr === arr1
19:33:52.438 true

Using Angular framework is the best way to keep pointer to source object when you update collections without large amount of watchers and reloads.

How do you get assembler output from C/C++ source in gcc?

recently i wanted to know the assembly of each functions in a program
this is how i did it.

$ gcc main.c                      // main.c source file
$ gdb a.exe                       // gdb a.out in linux
  (gdb) disass main               // note here main is a function
                                  // similary it can be done for other functions

PostgreSQL query to list all table names?

Open up the postgres terminal with the databse you would like:

psql dbname (run this line in a terminal)

then, run this command in the postgres environment

\d

This will describe all tables by name. Basically a list of tables by name ascending.

Then you can try this to describe a table by fields:

\d tablename.

Hope this helps.

javax.faces.application.ViewExpiredException: View could not be restored

Introduction

The ViewExpiredException will be thrown whenever the javax.faces.STATE_SAVING_METHOD is set to server (default) and the enduser sends a HTTP POST request on a view via <h:form> with <h:commandLink>, <h:commandButton> or <f:ajax>, while the associated view state isn't available in the session anymore.

The view state is identified as value of a hidden input field javax.faces.ViewState of the <h:form>. With the state saving method set to server, this contains only the view state ID which references a serialized view state in the session. So, when the session is expired for some reason (either timed out in server or client side, or the session cookie is not maintained anymore for some reason in browser, or by calling HttpSession#invalidate() in server, or due a server specific bug with session cookies as known in WildFly), then the serialized view state is not available anymore in the session and the enduser will get this exception. To understand the working of the session, see also How do servlets work? Instantiation, sessions, shared variables and multithreading.

There is also a limit on the amount of views JSF will store in the session. When the limit is hit, then the least recently used view will be expired. See also com.sun.faces.numberOfViewsInSession vs com.sun.faces.numberOfLogicalViews.

With the state saving method set to client, the javax.faces.ViewState hidden input field contains instead the whole serialized view state, so the enduser won't get a ViewExpiredException when the session expires. It can however still happen on a cluster environment ("ERROR: MAC did not verify" is symptomatic) and/or when there's a implementation-specific timeout on the client side state configured and/or when server re-generates the AES key during restart, see also Getting ViewExpiredException in clustered environment while state saving method is set to client and user session is valid how to solve it.

Regardless of the solution, make sure you do not use enableRestoreView11Compatibility. it does not at all restore the original view state. It basically recreates the view and all associated view scoped beans from scratch and hereby thus losing all of original data (state). As the application will behave in a confusing way ("Hey, where are my input values..??"), this is very bad for user experience. Better use stateless views or <o:enableRestorableView> instead so you can manage it on a specific view only instead of on all views.

As to the why JSF needs to save view state, head to this answer: Why JSF saves the state of UI components on server?

Avoiding ViewExpiredException on page navigation

In order to avoid ViewExpiredException when e.g. navigating back after logout when the state saving is set to server, only redirecting the POST request after logout is not sufficient. You also need to instruct the browser to not cache the dynamic JSF pages, otherwise the browser may show them from the cache instead of requesting a fresh one from the server when you send a GET request on it (e.g. by back button).

The javax.faces.ViewState hidden field of the cached page may contain a view state ID value which is not valid anymore in the current session. If you're (ab)using POST (command links/buttons) instead of GET (regular links/buttons) for page-to-page navigation, and click such a command link/button on the cached page, then this will in turn fail with a ViewExpiredException.

To fire a redirect after logout in JSF 2.0, either add <redirect /> to the <navigation-case> in question (if any), or add ?faces-redirect=true to the outcome value.

<h:commandButton value="Logout" action="logout?faces-redirect=true" />

or

public String logout() {
    // ...
    return "index?faces-redirect=true";
}

To instruct the browser to not cache the dynamic JSF pages, create a Filter which is mapped on the servlet name of the FacesServlet and adds the needed response headers to disable the browser cache. E.g.

@WebFilter(servletNames={"Faces Servlet"}) // Must match <servlet-name> of your FacesServlet.
public class NoCacheFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;

        if (!req.getRequestURI().startsWith(req.getContextPath() + ResourceHandler.RESOURCE_IDENTIFIER)) { // Skip JSF resources (CSS/JS/Images/etc)
            res.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
            res.setHeader("Pragma", "no-cache"); // HTTP 1.0.
            res.setDateHeader("Expires", 0); // Proxies.
        }

        chain.doFilter(request, response);
    }

    // ...
}

Avoiding ViewExpiredException on page refresh

In order to avoid ViewExpiredException when refreshing the current page when the state saving is set to server, you not only need to make sure you are performing page-to-page navigation exclusively by GET (regular links/buttons), but you also need to make sure that you are exclusively using ajax to submit the forms. If you're submitting the form synchronously (non-ajax) anyway, then you'd best either make the view stateless (see later section), or to send a redirect after POST (see previous section).

Having a ViewExpiredException on page refresh is in default configuration a very rare case. It can only happen when the limit on the amount of views JSF will store in the session is hit. So, it will only happen when you've manually set that limit way too low, or that you're continuously creating new views in the "background" (e.g. by a badly implemented ajax poll in the same page or by a badly implemented 404 error page on broken images of the same page). See also com.sun.faces.numberOfViewsInSession vs com.sun.faces.numberOfLogicalViews for detail on that limit. Another cause is having duplicate JSF libraries in runtime classpath conflicting each other. The correct procedure to install JSF is outlined in our JSF wiki page.

Handling ViewExpiredException

When you want to handle an unavoidable ViewExpiredException after a POST action on an arbitrary page which was already opened in some browser tab/window while you're logged out in another tab/window, then you'd like to specify an error-page for that in web.xml which goes to a "Your session is timed out" page. E.g.

<error-page>
    <exception-type>javax.faces.application.ViewExpiredException</exception-type>
    <location>/WEB-INF/errorpages/expired.xhtml</location>
</error-page>

Use if necessary a meta refresh header in the error page in case you intend to actually redirect further to home or login page.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>Session expired</title>
        <meta http-equiv="refresh" content="0;url=#{request.contextPath}/login.xhtml" />
    </head>
    <body>
        <h1>Session expired</h1>
        <h3>You will be redirected to login page</h3>
        <p><a href="#{request.contextPath}/login.xhtml">Click here if redirect didn't work or when you're impatient</a>.</p>
    </body>
</html>

(the 0 in content represents the amount of seconds before redirect, 0 thus means "redirect immediately", you can use e.g. 3 to let the browser wait 3 seconds with the redirect)

Note that handling exceptions during ajax requests requires a special ExceptionHandler. See also Session timeout and ViewExpiredException handling on JSF/PrimeFaces ajax request. You can find a live example at OmniFaces FullAjaxExceptionHandler showcase page (this also covers non-ajax requests).

Also note that your "general" error page should be mapped on <error-code> of 500 instead of an <exception-type> of e.g. java.lang.Exception or java.lang.Throwable, otherwise all exceptions wrapped in ServletException such as ViewExpiredException would still end up in the general error page. See also ViewExpiredException shown in java.lang.Throwable error-page in web.xml.

<error-page>
    <error-code>500</error-code>
    <location>/WEB-INF/errorpages/general.xhtml</location>
</error-page>

Stateless views

A completely different alternative is to run JSF views in stateless mode. This way nothing of JSF state will be saved and the views will never expire, but just be rebuilt from scratch on every request. You can turn on stateless views by setting the transient attribute of <f:view> to true:

<f:view transient="true">

</f:view>

This way the javax.faces.ViewState hidden field will get a fixed value of "stateless" in Mojarra (have not checked MyFaces at this point). Note that this feature was introduced in Mojarra 2.1.19 and 2.2.0 and is not available in older versions.

The consequence is that you cannot use view scoped beans anymore. They will now behave like request scoped beans. One of the disadvantages is that you have to track the state yourself by fiddling with hidden inputs and/or loose request parameters. Mainly those forms with input fields with rendered, readonly or disabled attributes which are controlled by ajax events will be affected.

Note that the <f:view> does not necessarily need to be unique throughout the view and/or reside in the master template only. It's also completely legit to redeclare and nest it in a template client. It basically "extends" the parent <f:view> then. E.g. in master template:

<f:view contentType="text/html">
    <ui:insert name="content" />
</f:view>

and in template client:

<ui:define name="content">
    <f:view transient="true">
        <h:form>...</h:form>
    </f:view>
</f:view>

You can even wrap the <f:view> in a <c:if> to make it conditional. Note that it would apply on the entire view, not only on the nested contents, such as the <h:form> in above example.

See also


Unrelated to the concrete problem, using HTTP POST for pure page-to-page navigation isn't very user/SEO friendly. In JSF 2.0 you should really prefer <h:link> or <h:button> over the <h:commandXxx> ones for plain vanilla page-to-page navigation.

So instead of e.g.

<h:form id="menu">
    <h:commandLink value="Foo" action="foo?faces-redirect=true" />
    <h:commandLink value="Bar" action="bar?faces-redirect=true" />
    <h:commandLink value="Baz" action="baz?faces-redirect=true" />
</h:form>

better do

<h:link value="Foo" outcome="foo" />
<h:link value="Bar" outcome="bar" />
<h:link value="Baz" outcome="baz" />

See also

Do you need to dispose of objects and set them to null?

Always call dispose. It is not worth the risk. Big managed enterprise applications should be treated with respect. No assumptions can be made or else it will come back to bite you.

Don't listen to leppie.

A lot of objects don't actually implement IDisposable, so you don't have to worry about them. If they genuinely go out of scope they will be freed automatically. Also I have never come across the situation where I have had to set something to null.

One thing that can happen is that a lot of objects can be held open. This can greatly increase the memory usage of your application. Sometimes it is hard to work out whether this is actually a memory leak, or whether your application is just doing a lot of stuff.

Memory profile tools can help with things like that, but it can be tricky.

In addition always unsubscribe from events that are not needed. Also be careful with WPF binding and controls. Not a usual situation, but I came across a situation where I had a WPF control that was being bound to an underlying object. The underlying object was large and took up a large amount of memory. The WPF control was being replaced with a new instance, and the old one was still hanging around for some reason. This caused a large memory leak.

In hindsite the code was poorly written, but the point is that you want to make sure that things that are not used go out of scope. That one took a long time to find with a memory profiler as it is hard to know what stuff in memory is valid, and what shouldn't be there.

How do I declare and initialize an array in Java?

Declare and initialize for Java 8 and later. Create a simple integer array:

int [] a1 = IntStream.range(1, 20).toArray();
System.out.println(Arrays.toString(a1));
// Output: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]

Create a random array for integers between [-50, 50] and for doubles [0, 1E17]:

int [] a2 = new Random().ints(15, -50, 50).toArray();
double [] a3 = new Random().doubles(5, 0, 1e17).toArray();

Power-of-two sequence:

double [] a4 = LongStream.range(0, 7).mapToDouble(i -> Math.pow(2, i)).toArray();
System.out.println(Arrays.toString(a4));
// Output: [1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0]

For String[] you must specify a constructor:

String [] a5 = Stream.generate(()->"I will not squeak chalk").limit(5).toArray(String[]::new);
System.out.println(Arrays.toString(a5));

Multidimensional arrays:

String [][] a6 = List.of(new String[]{"a", "b", "c"} , new String[]{"d", "e", "f", "g"})
    .toArray(new String[0][]);
System.out.println(Arrays.deepToString(a6));
// Output: [[a, b, c], [d, e, f, g]]

How to get the fields in an Object via reflection?

I've an object (basically a VO) in Java and I don't know its type. I need to get values which are not null in that object.

Maybe you don't necessary need reflection for that -- here is a plain OO design that might solve your problem:

  1. Add an interface Validation which expose a method validate which checks the fields and return whatever is appropriate.
  2. Implement the interface and the method for all VO.
  3. When you get a VO, even if it's concrete type is unknown, you can typecast it to Validation and check that easily.

I guess that you need the field that are null to display an error message in a generic way, so that should be enough. Let me know if this doesn't work for you for some reason.

checking for typeof error in JS

You can use obj.constructor.name to check the "class" of an object https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name#Function_names_in_classes

For Example

var error = new Error("ValidationError");
console.log(error.constructor.name);

The above line will log "Error" which is the class name of the object. This could be used with any classes in javascript, if the class is not using a property that goes by the name "name"