Programs & Examples On #Generic interface

Align DIV's to bottom or baseline

this works (i only tested ie & ff):

<html>
<head>
    <style type="text/css">
        #parent {
            height: 300px;
            width: 300px;
            background-color: #ccc;
            border: 1px solid red;
            position: relative;
        }
        #child  {
            height: 100px;
            width: 30px;
            background-color: #eee;
            border: 1px solid green;
            position: absolute;
            bottom: 0;
            left: 0;
        }
    </style>
</head>
<body>
    <div id="parent">parent
        <div id="child">child</div>
    </div>
    outside
</body>
</html>

hope that helps.

How to center an iframe horizontally?

In my case solution was on iframe class adding:

    display: block;
    margin-right: auto;
    margin-left: auto;

Could not load file or assembly ... The parameter is incorrect

You can also clear the packages directory and allow NuGet to re-download missing packages

it solved the issue for me

Redirecting new tab on button click.(Response.Redirect) in asp.net C#

Wouldn't you be better off with

<asp:HyperLink ID="HyperLink1" runat="server" 
            NavigateUrl="CMS_1.aspx" 
            Target="_blank">
    Click here
</asp:HyperLink>

Because, to replicate your desired behavior on an asp:Button, you have to call window.open on the OnClientClick event of the button which looks a lot less cleaner than the above solution. Plus asp:HyperLink is there to handle scenarios like this.

If you want to replicate this using an asp:Button, do this.

<asp:Button ID="btn" runat="Server" 
        Text="SUBMIT"
        OnClientClick="javascript:return openRequestedPopup();"/>

JavaScript function.

var windowObjectReference;

function openRequestedPopup() {
    windowObjectReference = window.open("CMS_1.aspx",
              "DescriptiveWindowName",
              "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes");
}

How to filter rows in pandas by regex

Write a Boolean function that checks the regex and use apply on the column

foo[foo['b'].apply(regex_function)]

Shell script to capture Process ID and kill it if exist

You probably wanted to write

`ps -ef | grep syncapp | awk '{print $2}'`

but I will endorse @PaulR's answer - killall -9 syncapp is a much better alternative.

How to comment multiple lines in Visual Studio Code?

The keyboard shortcut to comment multiple in Windows is shift+alt+A.

How to upload a file and JSON data in Postman?

If somebody needed:

body -> form-data

Add field name as array

enter image description here

VB.Net .Clear() or txtbox.Text = "" textbox clear methods

Add this code in the Module :

Public Sub ClearTextBoxes(frm As Form) 

    For Each Control In frm.Controls
        If TypeOf Control Is TextBox Then
            Control.Text = ""     'Clear all text
        End If       
    Next Control

End Sub

Add this code in the Form window to Call the Sub routine:

Private Sub Command1_Click()
    Call ClearTextBoxes(Me)
End Sub

Types in Objective-C on iOS

Note that you can also use the C99 fixed-width types perfectly well in Objective-C:

#import <stdint.h>
...
int32_t x; // guaranteed to be 32 bits on any platform

The wikipedia page has a decent description of what's available in this header if you don't have a copy of the C standard (you should, though, since Objective-C is just a tiny extension of C). You may also find the headers limits.h and inttypes.h to be useful.

Synchronous request in Node.js

sync-request

By far the most easiest one I've found and used is sync-request and it supports both node and the browser!

var request = require('sync-request');
var res = request('GET', 'http://google.com');
console.log(res.body.toString('utf-8'));

That's it, no crazy configuration, no complex lib installs, although it does have a lib fallback. Just works. I've tried other examples here and was stumped when there was much extra setup to do or installs didn't work!

Notes:

The example that sync-request uses doesn't play nice when you use res.getBody(), all get body does is accept an encoding and convert the response data. Just do res.body.toString(encoding) instead.

Use table name in MySQL SELECT "AS"

To declare a string literal as an output column, leave the Table off and just use Test. It doesn't need to be associated with a table among your joins, since it will be accessed only by its column alias. When using a metadata function like getColumnMeta(), the table name will be an empty string because it isn't associated with a table.

SELECT
  `field1`, 
  `field2`, 
  'Test' AS `field3` 
FROM `Test`;

Note: I'm using single quotes above. MySQL is usually configured to honor double quotes for strings, but single quotes are more widely portable among RDBMS.

If you must have a table alias name with the literal value, you need to wrap it in a subquery with the same name as the table you want to use:

SELECT
  field1,
  field2,
  field3
FROM 
  /* subquery wraps all fields to put the literal inside a table */
  (SELECT field1, field2, 'Test' AS field3 FROM Test) AS Test

Now field3 will come in the output as Test.field3.

When to use EntityManager.find() vs EntityManager.getReference() with JPA

Because a reference is 'managed', but not hydrated, it can also allow you to remove an entity by ID, without needing to load it into memory first.

As you can't remove an unmanaged entity, it's just plain silly to load all fields using find(...) or createQuery(...), only to immediately delete it.

MyLargeObject myObject = em.getReference(MyLargeObject.class, objectId);
em.remove(myObject);

Get the client's IP address in socket.io

on socket.io 1.3.4 you have the following possibilities.

socket.handshake.address,

socket.conn.remoteAddress or

socket.request.client._peername.address

Move layouts up when soft keyboard is shown?

I tried a method of Diego Ramírez, it works. In AndroidManifest:

    <activity
        android:name=".MainActivity"
        android:windowSoftInputMode="stateHidden|adjustResize">
        ...
    </activity>

In activity_main.xml:

<LinearLayout ...
    android:orientation="vertical">

<Space
    android:layout_width="wrap_content"
    android:layout_height="0dp"
    android:layout_weight="1" />

<EditText
    android:id="@+id/edName"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="@string/first_name"
    android:inputType="textPersonName" />

<EditText ...>
...
</LinearLayout>

Adding a leading zero to some values in column in MySQL

Possibly:

select lpad(column, 8, 0) from table;

Edited in response to question from mylesg, in comments below:

ok, seems to make the change on the query- but how do I make it stick (change it) permanently in the table? I tried an UPDATE instead of SELECT

I'm assuming that you used a query similar to:

UPDATE table SET columnName=lpad(nums,8,0);

If that was successful, but the table's values are still without leading-zeroes, then I'd suggest you probably set the column as a numeric type? If that's the case then you'd need to alter the table so that the column is of a text/varchar() type in order to preserve the leading zeroes:

First:

ALTER TABLE `table` CHANGE `numberColumn` `numberColumn` CHAR(8);

Second, run the update:

UPDATE table SET `numberColumn`=LPAD(`numberColum`, 8, '0');

This should, then, preserve the leading-zeroes; the down-side is that the column is no longer strictly of a numeric type; so you may have to enforce more strict validation (depending on your use-case) to ensure that non-numerals aren't entered into that column.

References:

JavaScript: Create and save file

_x000D_
_x000D_
setTimeout("create('Hello world!', 'myfile.txt', 'text/plain')");_x000D_
function create(text, name, type) {_x000D_
  var dlbtn = document.getElementById("dlbtn");_x000D_
  var file = new Blob([text], {type: type});_x000D_
  dlbtn.href = URL.createObjectURL(file);_x000D_
  dlbtn.download = name;_x000D_
}
_x000D_
<a href="javascript:void(0)" id="dlbtn"><button>click here to download your file</button></a>
_x000D_
_x000D_
_x000D_

Compiling a C++ program with gcc

It worked well for me. Just one line code in cmd.

First, confirm that you have installed the gcc (for c) or g++ (for c++) compiler.

In cmd for gcc type:

gcc --version

in cmd for g++ type:

g++ --version

If it is installed then proceed.

Now, compile your .c or .cpp using cmd

for .c syntax:

gcc -o exe_filename yourfilename.c

Example:

gcc -o myfile myfile.c

Here exe_filename (myfile in example) is the name of your .exe file which you want to produce after compilation (Note: i have not put any extension here). And yourfilename.c (myfile.c in example) is the your source file which has the .c extension.

Now go to folder containing your .c file, here you will find a file with .exe extension. Just open it. Hurray..

For .cpp syntax:

g++ -o exe_filename yourfilename.cpp

After it the process is same as for .c .

Excel Define a range based on a cell value

Old post but this is exactly what I needed, simple question, how to change it to count column rather than Row. Thankyou in advance. Novice to Excel.

=SUM(A1:INDIRECT(CONCATENATE("A",C5)))

I.e My data is A1 B1 C1 D1 etc rather then A1 A2 A3 A4.

Check if element at position [x] exists in the list

int? here = (list.ElementAtOrDefault(2) != 0 ? list[2]:(int?) null);

How to extract text from the PDF document?

I know that this topic is quite old, but this need is still alive. I read many documents, forum and script and build a new advanced one which supports compressed and uncompressed pdf :

https://gist.github.com/smalot/6183152

Hope it helps everone

How to make the overflow CSS property work with hidden as value

In addition to provided answers:

it seems like parent element (the one with overflow:hidden) must not be display:inline. Changing to display:inline-block worked for me.

_x000D_
_x000D_
.outer {_x000D_
  position: relative;_x000D_
  border: 1px dotted black;_x000D_
  padding: 5px;_x000D_
  overflow: hidden;_x000D_
}_x000D_
.inner {_x000D_
  position: absolute;_x000D_
  left: 50%;_x000D_
  margin-left: -20px;_x000D_
  top: 70%;_x000D_
  width: 40px;_x000D_
  height: 80px;_x000D_
  background: yellow;_x000D_
}
_x000D_
<span class="outer">_x000D_
  Some text_x000D_
  <span class="inner"></span>_x000D_
</span>_x000D_
<span class="outer" style="display:inline-block;">_x000D_
  Some text_x000D_
  <span class="inner"></span>_x000D_
</span>
_x000D_
_x000D_
_x000D_

How to check type of files without extensions in python?

With newer subprocess library, you can now use the following code (*nix only solution):

import subprocess
import shlex

filename = 'your_file'
cmd = shlex.split('file --mime-type {0}'.format(filename))
result = subprocess.check_output(cmd)
mime_type = result.split()[-1]
print mime_type

How to request Administrator access inside a batch file

@echo off and title can come before this code:

net session>nul 2>&1
if %errorlevel%==0 goto main
echo CreateObject("Shell.Application").ShellExecute "%~f0", "", "", "runas">"%temp%/elevate.vbs"
"%temp%/elevate.vbs"
del "%temp%/elevate.vbs"
exit

:main
    <code goes here>
exit

A lot of the other answers are overkill if you don't need to worry about the following:

  • Parameters
  • Working Directory (cd %~dp0 will change to the directory containing the batch file)

Can jQuery get all CSS styles associated with an element?

I had tried many different solutions. This was the only one that worked for me in that it was able to pick up on styles applied at class level and at style as directly attributed on the element. So a font set at css file level and one as a style attribute; it returned the correct font.

It is simple! (Sorry, can't find where I originally found it)

//-- html object
var element = htmlObject; //e.g document.getElementById
//-- or jquery object
var element = htmlObject[0]; //e.g $(selector)

var stylearray = document.defaultView.getComputedStyle(element, null);
var font = stylearray["font-family"]

Alternatively you can list all the style by cycling through the array

for (var key in stylearray) {
console.log(key + ': ' + stylearray[key];
}

jQuery append() vs appendChild()

The main difference is that appendChild is a DOM method and append is a jQuery method. The second one uses the first as you can see on jQuery source code

append: function() {
    return this.domManip(arguments, true, function( elem ) {
        if ( this.nodeType === 1 || this.nodeType === 11 || this.nodeType === 9 ) {
            this.appendChild( elem );
        }
    });
},

If you're using jQuery library on your project, you'll be safe always using append when adding elements to the page.

Check if a Python list item contains a string inside another string

def find_dog(new_ls):
    splt = new_ls.split()
    if 'dog' in splt:
        print("True")
    else:
        print('False')


find_dog("Is there a dog here?")

Windows batch file file download from a URL

AFAIK, Windows doesn't have a built-in commandline tool to download a file. But you can do it from a VBScript, and you can generate the VBScript file from batch using echo and output redirection:

@echo off

rem Windows has no built-in wget or curl, so generate a VBS script to do it:
rem -------------------------------------------------------------------------
set DLOAD_SCRIPT=download.vbs
echo Option Explicit                                                    >  %DLOAD_SCRIPT%
echo Dim args, http, fileSystem, adoStream, url, target, status         >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
echo Set args = Wscript.Arguments                                       >> %DLOAD_SCRIPT%
echo Set http = CreateObject("WinHttp.WinHttpRequest.5.1")              >> %DLOAD_SCRIPT%
echo url = args(0)                                                      >> %DLOAD_SCRIPT%
echo target = args(1)                                                   >> %DLOAD_SCRIPT%
echo WScript.Echo "Getting '" ^& target ^& "' from '" ^& url ^& "'..."  >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
echo http.Open "GET", url, False                                        >> %DLOAD_SCRIPT%
echo http.Send                                                          >> %DLOAD_SCRIPT%
echo status = http.Status                                               >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
echo If status ^<^> 200 Then                                            >> %DLOAD_SCRIPT%
echo    WScript.Echo "FAILED to download: HTTP Status " ^& status       >> %DLOAD_SCRIPT%
echo    WScript.Quit 1                                                  >> %DLOAD_SCRIPT%
echo End If                                                             >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
echo Set adoStream = CreateObject("ADODB.Stream")                       >> %DLOAD_SCRIPT%
echo adoStream.Open                                                     >> %DLOAD_SCRIPT%
echo adoStream.Type = 1                                                 >> %DLOAD_SCRIPT%
echo adoStream.Write http.ResponseBody                                  >> %DLOAD_SCRIPT%
echo adoStream.Position = 0                                             >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
echo Set fileSystem = CreateObject("Scripting.FileSystemObject")        >> %DLOAD_SCRIPT%
echo If fileSystem.FileExists(target) Then fileSystem.DeleteFile target >> %DLOAD_SCRIPT%
echo adoStream.SaveToFile target                                        >> %DLOAD_SCRIPT%
echo adoStream.Close                                                    >> %DLOAD_SCRIPT%
echo.                                                                   >> %DLOAD_SCRIPT%
rem -------------------------------------------------------------------------

cscript //Nologo %DLOAD_SCRIPT% http://example.com targetPathAndFile.html

More explanation here

What does <T> denote in C#

It is a Generic Type Parameter.

A generic type parameter allows you to specify an arbitrary type T to a method at compile-time, without specifying a concrete type in the method or class declaration.

For example:

public T[] Reverse<T>(T[] array)
{
    var result = new T[array.Length];
    int j=0;
    for(int i=array.Length - 1; i>= 0; i--)
    {
        result[j] = array[i];
        j++;
    }
    return result;
}

reverses the elements in an array. The key point here is that the array elements can be of any type, and the function will still work. You specify the type in the method call; type safety is still guaranteed.

So, to reverse an array of strings:

string[] array = new string[] { "1", "2", "3", "4", "5" };
var result = reverse(array);

Will produce a string array in result of { "5", "4", "3", "2", "1" }

This has the same effect as if you had called an ordinary (non-generic) method that looks like this:

public string[] Reverse(string[] array)
{
    var result = new string[array.Length];
    int j=0;
    for(int i=array.Length - 1; i >= 0; i--)
    {
        result[j] = array[i];
        j++;
    }
    return result;
}

The compiler sees that array contains strings, so it returns an array of strings. Type string is substituted for the T type parameter.


Generic type parameters can also be used to create generic classes. In the example you gave of a SampleCollection<T>, the T is a placeholder for an arbitrary type; it means that SampleCollection can represent a collection of objects, the type of which you specify when you create the collection.

So:

var collection = new SampleCollection<string>();

creates a collection that can hold strings. The Reverse method illustrated above, in a somewhat different form, can be used to reverse the collection's members.

Creating virtual directories in IIS express

I had to make the entry in the [project].vs\config\applicationhost.config file.

Prior to this, it worked from deployment but not from code.

In LINQ, select all values of property X where X != null

// if you need to check if all items' MyProperty doesn't have null

if (list.All(x => x.MyProperty != null))
// do something

// or if you need to check if at least one items' property has doesn't have null

if (list.Any(x => x.MyProperty != null))
// do something

But you always have to check for null

Path to MSBuild

Poking around the registry, it looks like

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\2.0
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\3.5
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\4.0

may be what you're after; fire up regedit.exe and have a look.

Query via command line (per Nikolay Botev)

reg.exe query "HKLM\SOFTWARE\Microsoft\MSBuild\ToolsVersions\4.0" /v MSBuildToolsPath

Query via PowerShell (per MovGP0)

dir HKLM:\SOFTWARE\Microsoft\MSBuild\ToolsVersions\

How are VST Plugins made?

I know this is 3 years old, but for everyone reading this now: Don't stick to VST, AU or any vendor's format. Steinberg has stopped supporting VST2, and people are in trouble porting their code to newer formats, because it's too tied to VST2.

These tutorials cover creating plugins that run on Win/Mac, 32/64, all plugin formats from the same code base.

window.onload vs document.onload

Add Event Listener

<script type="text/javascript">
  document.addEventListener("DOMContentLoaded", function(event) {
      // - Code to execute when all DOM content is loaded. 
      // - including fonts, images, etc.
  });
</script>


Update March 2017

1 Vanilla JavaScript

window.addEventListener('load', function() {
    console.log('All assets are loaded')
})


2 jQuery

$(window).on('load', function() {
    console.log('All assets are loaded')
})


Good Luck.

Pull new updates from original GitHub repository into forked GitHub repository

You have to add the original repository (the one you forked) as a remote.

From the GitHub documentation on forking a repository:

Screenshot of the old GitHub interface with a rectangular lens around the "Fork" button

Once the clone is complete your repo will have a remote named “origin” that points to your fork on GitHub.
Don’t let the name confuse you, this does not point to the original repo you forked from. To help you keep track of that repo we will add another remote named “upstream”:

$ cd PROJECT_NAME
$ git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
$ git fetch upstream

# then: (like "git pull" which is fetch + merge)
$ git merge upstream/master master

# or, better, replay your local work on top of the fetched branch
# like a "git pull --rebase"
$ git rebase upstream/master

There's also a command-line tool (hub) which can facilitate the operations above.

Here's a visual of how it works:

Flowchart on the result after the commands are executed

See also "Are Git forks actually Git clones?".

Opening popup windows in HTML

HTML alone does not support this. You need to use some JS.

And also consider nowadays people use popup blocker in browsers.

<a href="javascript:window.open('document.aspx','mypopuptitle','width=600,height=400')">open popup</a>

The cast to value type 'Int32' failed because the materialized value is null

I was also facing the same problem and solved through making column as nullable using "?" operator.

Sequnce = db.mstquestionbanks.Where(x => x.IsDeleted == false && x.OrignalFormID == OriginalFormIDint).Select(x=><b>(int?)x.Sequence</b>).Max().ToString();

Sometimes null is returned.

What is the reason and how to avoid the [FIN, ACK] , [RST] and [RST, ACK]

Here is a rough explanation of the concepts.

[ACK] is the acknowledgement that the previously sent data packet was received.

[FIN] is sent by a host when it wants to terminate the connection; the TCP protocol requires both endpoints to send the termination request (i.e. FIN).

So, suppose

  • host A sends a data packet to host B
  • and then host B wants to close the connection.
  • Host B (depending on timing) can respond with [FIN,ACK] indicating that it received the sent packet and wants to close the session.
  • Host A should then respond with a [FIN,ACK] indicating that it received the termination request (the ACK part) and that it too will close the connection (the FIN part).

However, if host A wants to close the session after sending the packet, it would only send a [FIN] packet (nothing to acknowledge) but host B would respond with [FIN,ACK] (acknowledges the request and responds with FIN).

Finally, some TCP stacks perform half-duplex termination, meaning that they can send [RST] instead of the usual [FIN,ACK]. This happens when the host actively closes the session without processing all the data that was sent to it. Linux is one operating system which does just this.

You can find a more detailed and comprehensive explanation here.

Failed to find target with hash string 'android-25'

I have got same error for Android-28. In SDK manager - SDK Platform it shows me that Android API 28 is partially installed and no further updates available. so that I updated ANDROID-SDK-BUILD-TOOLS from SDK Tools and after restarting project. It will work. This might be helpful for other who faces same issue as I faced.

How can I give access to a private GitHub repository?

Two steps:
1. Login and click "Invite someone" in the right column under "People". Enter and select persons github id.
2. It will then give you the option to "Invite Username to some teams" at which point you simply check off which teams you want to add them to then click "Send Invitation"

Alternatively:
1. Get the persons github id (not their email)
2. Navigate to the repository you would like to add the user to
3. Click "Settings" in the right column (not the gearbox settings along the top)
4. Click Collaborators long the left column
5. Select the repository name
6. Where it reads "Invite or add users to team" add the persons github id
7. An invitation will then be e-mailed.

Please let me know how this worked for you!

How do I limit the number of decimals printed for a double?

okay one other solution that I thought of just for the fun of it would be to turn your decimal into a string and then cut the string into 2 strings, one containing the point and the decimals and the other containing the Int to the left of the point. after that you limit the String of the point and decimals to 3 chars, one for the decimal point and the others for the decimals. then just recombine.

double shippingCost = ((nCartons * 1.44) + (lbs + 1) * 0.96) + 3.0;
String ShippingCost = (String) shippingCost;
String decimalCost = ShippingCost.subString(indexOf('.'),ShippingCost.Length());
ShippingCost = ShippingCost.subString(0,indexOf('.'));
ShippingCost = ShippingCost + decimalCost;

There! Simple, right?

Bootstrap select dropdown list placeholder

Add hidden attribute:

<select>
    <option value="" selected disabled hidden>Please select</option>
    <option value="">A</option>
    <option value="">B</option>
    <option value="">C</option>
</select>

'cannot open git-upload-pack' error in Eclipse when cloning or pushing git repository

I added -Dhttps.protocols=TLSv1.1,TLSv1.2 to eclipse.ini and it's working. I use java 1.7

SQL-Server: Error - Exclusive access could not be obtained because the database is in use

Setting the DB to single-user mode didn't work for me, but taking it offline, and then bringing it back online did work. It's in the right-click menu of the DB, under Tasks.

Be sure to check the 'Drop All Active Connections' option in the dialog.

Convert character to ASCII code in JavaScript

String.prototype.charCodeAt() can convert string characters to ASCII numbers. For example:

"ABC".charCodeAt(0) // returns 65

For opposite use String.fromCharCode(10) that convert numbers to equal ASCII character. This function can accept multiple numbers and join all the characters then return the string. Example:

String.fromCharCode(65,66,67); // returns 'ABC'

Here is a quick ASCII characters reference:

{
"31": "",      "32": " ",     "33": "!",     "34": "\"",    "35": "#",    
"36": "$",     "37": "%",     "38": "&",     "39": "'",     "40": "(",    
"41": ")",     "42": "*",     "43": "+",     "44": ",",     "45": "-",    
"46": ".",     "47": "/",     "48": "0",     "49": "1",     "50": "2",    
"51": "3",     "52": "4",     "53": "5",     "54": "6",     "55": "7",    
"56": "8",     "57": "9",     "58": ":",     "59": ";",     "60": "<",    
"61": "=",     "62": ">",     "63": "?",     "64": "@",     "65": "A",    
"66": "B",     "67": "C",     "68": "D",     "69": "E",     "70": "F",    
"71": "G",     "72": "H",     "73": "I",     "74": "J",     "75": "K",    
"76": "L",     "77": "M",     "78": "N",     "79": "O",     "80": "P",    
"81": "Q",     "82": "R",     "83": "S",     "84": "T",     "85": "U",    
"86": "V",     "87": "W",     "88": "X",     "89": "Y",     "90": "Z",    
"91": "[",     "92": "\\",    "93": "]",     "94": "^",     "95": "_",    
"96": "`",     "97": "a",     "98": "b",     "99": "c",     "100": "d",    
"101": "e",    "102": "f",    "103": "g",    "104": "h",    "105": "i",    
"106": "j",    "107": "k",    "108": "l",    "109": "m",    "110": "n",    
"111": "o",    "112": "p",    "113": "q",    "114": "r",    "115": "s",    
"116": "t",    "117": "u",    "118": "v",    "119": "w",    "120": "x",    
"121": "y",    "122": "z",    "123": "{",    "124": "|",    "125": "}",    
"126": "~",    "127": ""
}

INSTALL_FAILED_DUPLICATE_PERMISSION... C2D_MESSAGE

While giving this error it will clearly mention the package name of the app because of which the permission was denied. And just uninstalling the application will not solve the problem. In order to solve problem we need to do the following step:

  1. Go to settings
  2. Go to app
  3. Go to downloaded app list
  4. You can see the uninstalled application in the list
  5. Click on the application, go to more option
  6. Click on uninstall for all users options

Problem solved :D

Best way to do a split pane in HTML

Here is my lightweight vanilla JavaScript approach, using Flexbox:

http://codepen.io/lingtalfi/pen/zoNeJp

It was tested successfully in Google Chrome 54, Firefox 50, Safari 10, don't know about other browsers.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.rawgit.com/lingtalfi/simpledrag/master/simpledrag.js"></script>

    <style type="text/css">

        html, body {
            height: 100%;
        }

        .panes-container {
            display: flex;
            width: 100%;
            overflow: hidden;
        }

        .left-pane {
            width: 18%;
            background: #ccc;
        }

        .panes-separator {
            width: 2%;
            background: red;
            position: relative;
            cursor: col-resize;
        }

        .right-pane {
            flex: auto;
            background: #eee;
        }

        .panes-container,
        .panes-separator,
        .left-pane,
        .right-pane {
            margin: 0;
            padding: 0;
            height: 100%;
        }

    </style>

</head>

<body>

<div class="panes-container">
    <div class="left-pane" id="left-pane">
        <p>I'm the left pane</p>
        <ul>
            <li><a href="#">Item 1</a></li>
            <li><a href="#">Item 2</a></li>
            <li><a href="#">Item 3</a></li>
        </ul>
    </div>
    <div class="panes-separator" id="panes-separator"></div>
    <div class="right-pane" id="right-pane">
        <p>And I'm the right pane</p>
        <p>
            Lorem ipsum dolor sit amet, consectetur adipisicing elit. A accusantium at cum cupiditate dolorum, eius eum
            eveniet facilis illum maiores molestiae necessitatibus optio possimus sequi sunt, vel voluptate. Asperiores,
            voluptate!
        </p>
    </div>
</div>


<script>


    var leftPane = document.getElementById('left-pane');
    var rightPane = document.getElementById('right-pane');
    var paneSep = document.getElementById('panes-separator');

    // The script below constrains the target to move horizontally between a left and a right virtual boundaries.
    // - the left limit is positioned at 10% of the screen width
    // - the right limit is positioned at 90% of the screen width
    var leftLimit = 10;
    var rightLimit = 90;


    paneSep.sdrag(function (el, pageX, startX, pageY, startY, fix) {

        fix.skipX = true;

        if (pageX < window.innerWidth * leftLimit / 100) {
            pageX = window.innerWidth * leftLimit / 100;
            fix.pageX = pageX;
        }
        if (pageX > window.innerWidth * rightLimit / 100) {
            pageX = window.innerWidth * rightLimit / 100;
            fix.pageX = pageX;
        }

        var cur = pageX / window.innerWidth * 100;
        if (cur < 0) {
            cur = 0;
        }
        if (cur > window.innerWidth) {
            cur = window.innerWidth;
        }


        var right = (100-cur-2);
        leftPane.style.width = cur + '%';
        rightPane.style.width = right + '%';

    }, null, 'horizontal');


</script>

</body>
</html>

This HTML code depends on the simpledrag vanilla JavaScript lightweight library (less than 60 lines of code).

How to change row color in datagridview?

Works on Visual Studio 2010. (I tried it and it works!) It will paint your entire row.

  1. Create a button for the datagridview.
  2. Create a CellClick event and put the next line of code inside of it.

if (dataGridView3.Columns[e.ColumnIndex].Index.Equals(0)    
{
    dataGridView3.Rows[e.RowIndex].DefaultCellStyle.BackColor = Color.Beige;
}

Rename multiple files based on pattern in Unix

Using StringSolver tools (windows & Linux bash) which process by examples:

filter fghfilea ok fghreport ok notfghfile notok; mv --all --filter fghfilea jklfilea

It first computes a filter based on examples, where the input is the file names and the output (ok and notok, arbitrary strings). If filter had the option --auto or was invoked alone after this command, it would create a folder ok and a folder notok and push files respectively to them.

Then using the filter, the mv command is a semi-automatic move which becomes automatic with the modifier --auto. Using the previous filter thanks to --filter, it finds a mapping from fghfilea to jklfilea and then applies it on all filtered files.


Other one-line solutions

Other equivalent ways of doing the same (each line is equivalent), so you can choose your favorite way of doing it.

filter fghfilea ok fghreport ok notfghfile notok; mv --filter fghfilea jklfilea; mv
filter fghfilea ok fghreport ok notfghfile notok; auto --all --filter fghfilea "mv fghfilea jklfilea"
# Even better, automatically infers the file name
filter fghfilea ok fghreport ok notfghfile notok; auto --all --filter "mv fghfilea jklfilea"

Multi-step solution

To carefully find if the commands are performing well, you can type the following:

filter fghfilea ok
filter fghfileb ok
filter fghfileb notok

and when you are confident that the filter is good, perform the first move:

mv fghfilea jklfilea

If you want to test, and use the previous filter, type:

mv --test --filter

If the transformation is not what you wanted (e.g. even with mv --explain you see that something is wrong), you can type mv --clear to restart moving files, or add more examples mv input1 input2 where input1 and input2 are other examples

When you are confident, just type

mv --filter

and voilà! All the renaming is done using the filter.

DISCLAIMER: I am a co-author of this work made for academic purposes. There might also be a bash-producing feature soon.

see if two files have the same content in python

I'm not sure if you want to find duplicate files or just compare two single files. If the latter, the above approach (filecmp) is better, if the former, the following approach is better.

There are lots of duplicate files detection questions here. Assuming they are not very small and that performance is important, you can

  • Compare file sizes first, discarding all which doesn't match
  • If file sizes match, compare using the biggest hash you can handle, hashing chunks of files to avoid reading the whole big file

Here's is an answer with Python implementations (I prefer the one by nosklo, BTW)

how to use html2canvas and jspdf to export to pdf in a proper and simple way

I have made a jsfiddle for you.

 <canvas id="canvas" width="480" height="320"></canvas> 
      <button id="download">Download Pdf</button>

'

        html2canvas($("#canvas"), {
            onrendered: function(canvas) {         
                var imgData = canvas.toDataURL(
                    'image/png');              
                var doc = new jsPDF('p', 'mm');
                doc.addImage(imgData, 'PNG', 10, 10);
                doc.save('sample-file.pdf');
            }
        });

jsfiddle: http://jsfiddle.net/rpaul/p4s5k59s/5/

Tested in Chrome38, IE11 and Firefox 33. Seems to have issues with Safari. However, Andrew got it working in Safari 8 on Mac OSx by switching to JPEG from PNG. For details, see his comment below.

scp (secure copy) to ec2 instance without password

I figured it out. I had the arguments in the wrong order. This works:

scp -i mykey.pem somefile.txt [email protected]:/

Programmatically shut down Spring Boot application

In the application you can use SpringApplication. This has a static exit() method that takes two arguments: the ApplicationContext and an ExitCodeGenerator:

i.e. you can declare this method:

@Autowired
public void shutDown(ExecutorServiceExitCodeGenerator exitCodeGenerator) {
    SpringApplication.exit(applicationContext, exitCodeGenerator);
}

Inside the Integration tests you can achieved it by adding @DirtiesContext annotation at class level:

  • @DirtiesContext(classMode=ClassMode.AFTER_CLASS) - The associated ApplicationContext will be marked as dirty after the test class.
  • @DirtiesContext(classMode=ClassMode.AFTER_EACH_TEST_METHOD) - The associated ApplicationContext will be marked as dirty after each test method in the class.

i.e.

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = {Application.class},
    webEnvironment= SpringBootTest.WebEnvironment.DEFINED_PORT, properties = {"server.port:0"})
@DirtiesContext(classMode= DirtiesContext.ClassMode.AFTER_CLASS)
public class ApplicationIT {
...

How to get file creation date/time in Bash/Debian?

Cited from https://unix.stackexchange.com/questions/50177/birth-is-empty-on-ext4/131347#131347 , the following shellscript would work to get creation time:

get_crtime() {
   for target in "${@}"; do
       inode=$(stat -c %i "${target}")
       fs=$(df "${target}"  | tail -1 | awk '{print $1}')
       crtime=$(sudo debugfs -R 'stat <'"${inode}"'>' "${fs}" 2>/dev/null | grep -oP 'crtime.*--\s*\K.*')
       printf "%s\t%s\n" "${target}" "${crtime}"
   done
}

Nodejs - Redirect url

Try this:

this.statusCode = 302;
this.setHeader('Location', '/url/to/redirect');
this.end();

How do I iterate through each element in an n-dimensional matrix in MATLAB?

If you look deeper into the other uses of size you can see that you can actually get a vector of the size of each dimension. This link shows you the documentation:

www.mathworks.com/access/helpdesk/help/techdoc/ref/size.html

After getting the size vector, iterate over that vector. Something like this (pardon my syntax since I have not used Matlab since college):

d = size(m);
dims = ndims(m);
for dimNumber = 1:dims
   for i = 1:d[dimNumber]
      ...

Make this into actual Matlab-legal syntax, and I think it would do what you want.

Also, you should be able to do Linear Indexing as described here.

Bootstrap: change background color

You could hard code it.

<div class="col-md-6" style="background-color:blue;">
</div>

<div class="col-md-6" style="background-color:white;">
</div>

Linux: command to open URL in default browser

###1     Desktop's -or- Console use:
sensible-browser $URL; # Opinion: best. Target preferred APP.
# My-Server translates to: w3m [options] [URL or filename] 
## [ -z "$BROWSER" ] && echo "Empty"
# Then, Set the BROWSER environment variable to your desired browser.

###2     Alternative 
# Desktop (if [command-not-found] out-Dated)
x-www-browser http://tv.jimmylandstudios.xyz # firefox

###3     !- A Must Know -!
# Desktop (/usr/share/applications/*.desktop)
xdg-open $URI # opens about anything on Linux (w/ .desktop file)

opening html from google drive

Steps:

  1. Upload html file to the google drive and share it as "Public on the web" after uploading just make sure that the content of your html is not modified in the drive.
  2. Right click on the shared file and click on 'Get link' and save it to notepad it will look something like 'https://drive.google.com/open?id=0B55nkHvMDw18T3VaYjY3NEE4SEE'
  3. Take the code (about 28 character alphanumeric) after '=' sign from the above link and paste it after 'https://googledrive.com/host/' now 'https://googledrive.com/host/0B55nkHvMDw18T3VaYjY3NEE4SEE' is your actual sharable url link, open the html file from address bar of the browser using this url.

In a Dockerfile, How to update PATH environment variable?

[I mentioned this in response to the selected answer, but it was suggested to make it more prominent as an answer of its own]

It should be noted that

ENV PATH="/opt/gtk/bin:${PATH}" 

may not be the same as

ENV PATH="/opt/gtk/bin:$PATH" 

The former, with curly brackets, might provide you with the host's PATH. The documentation doesn't suggest this would be the case, but I have observed that it is. This is simple to check just do RUN echo $PATH and compare it to RUN echo ${PATH}

How to determine the current iPhone/device model?

There is a helper library for this.

Swift 5

pod 'DeviceKit', '~> 2.0'

Swift 4.0 - Swift 4.2

pod 'DeviceKit', '~> 1.3'

if you just want to determine the model and make something accordingly.

You can use like that :

let isIphoneX = Device().isOneOf([.iPhoneX, .simulator(.iPhoneX)])

In a function :

func isItIPhoneX() -> Bool {
    let device = Device()
    let check = device.isOneOf([.iPhoneX, .iPhoneXr , .iPhoneXs , .iPhoneXsMax ,
                                .simulator(.iPhoneX), .simulator(.iPhoneXr) , .simulator(.iPhoneXs) , .simulator(.iPhoneXsMax) ])
    return check
}

Inner join of DataTables in C#

This is my code. Not perfect, but working good. I hope it helps somebody:

    static System.Data.DataTable DtTbl (System.Data.DataTable[] dtToJoin)
    {
        System.Data.DataTable dtJoined = new System.Data.DataTable();

        foreach (System.Data.DataColumn dc in dtToJoin[0].Columns)
            dtJoined.Columns.Add(dc.ColumnName);

        foreach (System.Data.DataTable dt in dtToJoin)
            foreach (System.Data.DataRow dr1 in dt.Rows)
            {
                System.Data.DataRow dr = dtJoined.NewRow();
                foreach (System.Data.DataColumn dc in dtToJoin[0].Columns)
                    dr[dc.ColumnName] = dr1[dc.ColumnName];

                dtJoined.Rows.Add(dr);
            }

        return dtJoined;
    }

get the latest fragment in backstack

FragmentManager.findFragmentById(fragmentsContainerId) 

function returns link to top Fragment in backstack. Usage example:

    fragmentManager.addOnBackStackChangedListener(new OnBackStackChangedListener() {
        @Override
        public void onBackStackChanged() {
            Fragment fr = fragmentManager.findFragmentById(R.id.fragmentsContainer);
            if(fr!=null){
                Log.e("fragment=", fr.getClass().getSimpleName());
            }
        }
    });

Run bash script from Windows PowerShell

It also can be run by exporting the bash and sh of the gitbash C:\Program Files\git\bin\ in the Advance section of the environment variable of the Windows Server.

In Advance section in the path var kindly add the C:\Program Files\git\bin\ which will make the bash and the sh of the git-bash to be executable from the window cmd.

Then,

Run the shell file as

bash shellscript.sh or sh shellscript.sh

href="tel:" and mobile numbers

When dialing a number within the country you are in, you still need to dial the national trunk number before the rest of the number. For example, in Australia one would dial:

   0 - trunk prefix
   2 - Area code for New South Wales
6555 - STD code for a specific telephone exchange
1234 - Telephone Exchange specific extension.

For a mobile phone this becomes

   0 -      trunk prefix
   4 -      Area code for a mobile telephone
1234 5678 - Mobile telephone number

Now, when I want to dial via the international trunk, you need to drop the trunk prefix and replace it with the international dialing prefix

   + -      Short hand for the country trunk number
  61 -      Country code for Australia
   4 -      Area code for a mobile telephone
1234 5678 - Mobile telephone number

This is why you often find that the first digit of a telephone number is dropped when dialling internationally, even when using international prefixing to dial within the same country.

So as per the trunk prefix for Germany drop the 0 and add the +49 for Germany's international calling code (for example) giving:

_x000D_
_x000D_
<a href="tel:+496170961709" class="Blondie">_x000D_
    Call me, call me any, anytime_x000D_
      <b>Call me (call me) I'll arrive</b>_x000D_
        When you're ready we can share the wine!_x000D_
</a>
_x000D_
_x000D_
_x000D_

Convert a list of objects to an array of one of the object's properties

For everyone who is stuck with .NET 2.0, like me, try the following way (applicable to the example in the OP):

ConfigItemList.ConvertAll<string>(delegate (ConfigItemType ci) 
{ 
   return ci.Name; 
}).ToArray();

where ConfigItemList is your list variable.

File Upload without Form

Basing on this tutorial, here a very basic way to do that:

$('your_trigger_element_selector').on('click', function(){    
    var data = new FormData();
    data.append('input_file_name', $('your_file_input_selector').prop('files')[0]);
    // append other variables to data if you want: data.append('field_name_x', field_value_x);

    $.ajax({
        type: 'POST',               
        processData: false, // important
        contentType: false, // important
        data: data,
        url: your_ajax_path,
        dataType : 'json',  
        // in PHP you can call and process file in the same way as if it was submitted from a form:
        // $_FILES['input_file_name']
        success: function(jsonData){
            ...
        }
        ...
    }); 
});

Don't forget to add proper error handling

Use <Image> with a local file

ES6 solution:

import DefaultImage from '../assets/image.png';

const DEFAULT_IMAGE = Image.resolveAssetSource(DefaultImage).uri;

and then:

<Image source={{uri: DEFAULT_IMAGE}} />

Command Line Tools not working - OS X El Capitan, Sierra, High Sierra, Mojave

For Mojave

Uninstall Any old version of Command Line Tools:

sudo rm -rf /Library/Developer/CommandLineTools

Download and Install Command Line Tools 10.14 Mojave.

Unable to connect to any of the specified mysql hosts. C# MySQL

Try this:

MySqlConnectionStringBuilder conn_string = new MySqlConnectionStringBuilder();
conn_string.Server = "127.0.0.1";
conn_string.Port = 3306;
conn_string.UserID = "root";
conn_string.Password = "myPassword";
conn_string.Database = "myDB";



MySqlConnection MyCon = new MySqlConnection(conn_string.ToString());

try
{
    MyCon.Open();
    MessageBox.Show("Open");
    MyCon.Close();
    MessageBox.Show("Close");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

Shuffling a list of objects

from random import random
my_list = range(10)
shuffled_list = sorted(my_list, key=lambda x: random())

This alternative may be useful for some applications where you want to swap the ordering function.

How to make background of table cell transparent

I use the "transparent" keyword and it works perfect!

<style type="text/css">
#img table,tr, td {
    border: 1px solid transparent;
    align="center";
    border-spacing: 25px;
    border-collapse: collapse;
    border-width: 5px;
    padding: 5px;
    padding-left: 50px;
}

Android Studio - mergeDebugResources exception

My problem solve this one

compile fileTree(dir: 'libs', include: ['*.jar'])

to

provided fileTree(dir: 'libs', include: ['*.jar'])

Display string as html in asp.net mvc view

I had a similar problem recently, and google landed me here, so I put this answer here in case others land here as well, for completeness.

I noticed that when I had badly formatted html, I was actually having all my html tags stripped out, with just the non-tag content remaining. I particularly had a table with a missing opening table tag, and then all my html tags from the entire string where ripped out completely.

So, if the above doesn't work, and you're still scratching your head, then also check you html for being valid.

I notice even after I got it working, MVC was adding tbody tags where I had none. This tells me there is clean up happening (MVC 5), and that when it can't happen, it strips out all/some tags.

Access parent's parent from javascript object

I used something that resembles singleton pattern:

function myclass() = {
    var instance = this;

    this.Days = function() {
        var days = ["Piatek", "Sobota", "Niedziela"];
        return days;
    }

    this.EventTime = function(day, hours, minutes) {
        this.Day = instance.Days()[day];
        this.Hours = hours;
        this.minutes = minutes;
        this.TotalMinutes = day*24*60 + 60*hours + minutes;
    }
}

How to study design patterns?

The way I learned design patterns is by writing lots of really terrible software. When I was about 12, I have no idea what was good or bad. I just wrote piles of spaghetti code. Over the next 10 years or so, I learned from my mistakes. I discovered what worked and what didn't. I independently invented most of the common design patterns, so when I first heard what design patterns were, I was very excited to learn about them, then very disappointed that it was just a collection of names for things that I already knew intuitively. (that joke about teaching yourself C++ in 10 years isn't actually a joke)

Moral of the story: write lots of code. As others have said, practice, practice, practice. I think until you understand why your current design is bad and go looking for a better way, you won't have a good idea of where to apply various design patterns. Design pattern books should be providing you a refined solution and a common terminology to discuss it with other developers, not a paste-in solution to a problem you don't understand.

What could cause java.lang.reflect.InvocationTargetException?

  1. List all jar files from the Eclipse Navigator mode
  2. Verify that all the jar files are in binary mode

Replace tabs with spaces in vim

This article has an excellent vimrc script for handling tabs+spaces, and converting in between them.

These commands are provided:

Space2Tab Convert spaces to tabs, only in indents.

Tab2Space Convert tabs to spaces, only in indents.

RetabIndent Execute Space2Tab (if 'expandtab' is set), or Tab2Space (otherwise).

Each command accepts an argument that specifies the number of spaces in a tab column. By default, the 'tabstop' setting is used.

Source: http://vim.wikia.com/wiki/Super_retab#Script

" Return indent (all whitespace at start of a line), converted from
" tabs to spaces if what = 1, or from spaces to tabs otherwise.
" When converting to tabs, result has no redundant spaces.
function! Indenting(indent, what, cols)
  let spccol = repeat(' ', a:cols)
  let result = substitute(a:indent, spccol, '\t', 'g')
  let result = substitute(result, ' \+\ze\t', '', 'g')
  if a:what == 1
    let result = substitute(result, '\t', spccol, 'g')
  endif
  return result
endfunction

" Convert whitespace used for indenting (before first non-whitespace).
" what = 0 (convert spaces to tabs), or 1 (convert tabs to spaces).
" cols = string with number of columns per tab, or empty to use 'tabstop'.
" The cursor position is restored, but the cursor will be in a different
" column when the number of characters in the indent of the line is changed.
function! IndentConvert(line1, line2, what, cols)
  let savepos = getpos('.')
  let cols = empty(a:cols) ? &tabstop : a:cols
  execute a:line1 . ',' . a:line2 . 's/^\s\+/\=Indenting(submatch(0), a:what, cols)/e'
  call histdel('search', -1)
  call setpos('.', savepos)
endfunction

command! -nargs=? -range=% Space2Tab call IndentConvert(<line1>,<line2>,0,<q-args>)
command! -nargs=? -range=% Tab2Space call IndentConvert(<line1>,<line2>,1,<q-args>)
command! -nargs=? -range=% RetabIndent call IndentConvert(<line1>,<line2>,&et,<q-args>)

This helped me a bit more than the answers here did when I first went searching for a solution.

How to switch between hide and view password

In XML do like this

    <LinearLayout
          android:layout_height="wrap_content"
          android:layout_width="fill_parent"
          android:orientation="vertical"
          >
          <RelativeLayout
              android:id="@+id/REFReLayTellFriend"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="horizontal"
              >
          <EditText
              android:id="@+id/etpass1"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:background="@android:color/transparent"
              android:bottomLeftRadius="10dp"
              android:bottomRightRadius="50dp"
              android:fontFamily="@font/frutiger"
              android:gravity="start"
              android:inputType="textPassword"
              android:hint="@string/regpass_pass1"
              android:padding="20dp"
              android:paddingBottom="10dp"
              android:textColor="#000000"
              android:textColorHint="#d3d3d3"
              android:textSize="14sp"
              android:topLeftRadius="10dp"
              android:topRightRadius="10dp"/>
              <ImageButton
                  android:id="@+id/imgshowhide1"
                  android:layout_width="40dp"
                  android:layout_height="20dp"
                  android:layout_marginTop="20dp"
                  android:layout_marginRight="10dp"
                  android:background="@drawable/showpass"
                  android:layout_alignRight="@+id/etpass1"/>
          </RelativeLayout>    

 boolean show=true;
 //on image click inside password do this
 if(show){
                imgshowhide2.setBackgroundResource(0);
                imgshowhide2.setBackgroundResource(R.drawable.hide);
                etpass2.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);
                etpass2.setSelection(etpass2.getText().length());

                show=false;
            }else{
                imgshowhide2.setBackgroundResource(0);
                imgshowhide2.setBackgroundResource(R.drawable.showpass);
                //etpass1.setInputType(InputType.TYPE_TEXT);
                etpass2.setInputType(InputType.TYPE_CLASS_TEXT |
                        InputType.TYPE_TEXT_VARIATION_PASSWORD);
                etpass2.setSelection(etpass2.getText().length());
                show=true;
            }

How to convert a set to a list in python?

Python is a dynamically typed language, which means that you cannot define the type of the variable as you do in C or C++:

type variable = value

or

type variable(value)

In Python, you use coercing if you change types, or the init functions (constructors) of the types to declare a variable of a type:

my_set = set([1,2,3])
type my_set

will give you <type 'set'> for an answer.

If you have a list, do this:

my_list = [1,2,3]
my_set = set(my_list)

How to create a .gitignore file

I want my contribution as well. This time, animated one :)

VIM (mini tutorial):

i   - start editing
ESC - get back to normal mode
:w  - save 
:q  - quit

enter image description here

Angular - POST uploaded file

In my project , I use the XMLHttpRequest to send multipart/form-data. I think it will fit you to.

and the uploader code

let xhr = new XMLHttpRequest();
xhr.open('POST', 'http://www.example.com/rest/api', true);
xhr.withCredentials = true;
xhr.send(formData);

Here is example : https://github.com/wangzilong/angular2-multipartForm

Gson library in Android Studio

Add following dependency or download Gson jar file

implementation 'com.google.code.gson:gson:2.8.6'

Follow github repo for documentation and more.

How can I get the source code of a Python function?

The inspect module has methods for retrieving source code from python objects. Seemingly it only works if the source is located in a file though. If you had that I guess you wouldn't need to get the source from the object.


The following tests inspect.getsource(foo) using Python 3.6:

import inspect

def foo(arg1,arg2):
    #do something with args
    a = arg1 + arg2
    return a

source_foo = inspect.getsource(foo)  # foo is normal function
print(source_foo)

source_max = inspect.getsource(max)  # max is a built-in function
print(source_max)

This first prints:

def foo(arg1,arg2):
    #do something with args
    a = arg1 + arg2
    return a

Then fails on inspect.getsource(max) with the following error:

TypeError: <built-in function max> is not a module, class, method, function, traceback, frame, or code object

How do I give ASP.NET permission to write to a folder in Windows 7?

I know this is an old thread but to further expand the answer here, by default IIS 7.5 creates application pool identity accounts to run the worker process under. You can't search for these accounts like normal user accounts when adding file permissions. To add them into NTFS permission ACL you can type the entire name of the application pool identity and it will work.

It is just a slight difference in the way the application pool identity accounts are handle as they are seen to be virtual accounts.

Also the username of the application pool identity is "IIS AppPool\application pool name" so if it was the application pool DefaultAppPool the user account would be "IIS AppPool\DefaultAppPool".

These can be seen if you open computer management and look at the members of the local group IIS_IUSRS. The SID appended to the end of them is not need when adding the account into an NTFS permission ACL.

Hope that helps

Getting the current date in visual Basic 2008

Try this:

Dim regDate as Date = Date.Now()
Dim strDate as String = regDate.ToString("ddMMMyyyy")

strDate will look like so: 07Feb2012

Batch Script to Run as Administrator

Don't waste your time, use this one line command to run command line as administrator:

echo createobject("shell.application").shellexecute "cmd.exe",,,"runas",1 > runas.vbs & start /wait runas.vbs & del /f runas.vbs

if you want to start any application with administrator privilege you will just write the hole path for this application like this notepad++ in my program files for example :

echo createobject("shell.application").shellexecute "%programfiles%\Notepad++\notepad++.exe",,,"runas",1 > runas.vbs & start /wait runas.vbs

Tips for debugging .htaccess rewrite rules

Don't forget that in .htaccess files it is a relative URL that is matched.

In a .htaccess file the following RewriteRule will never match:

RewriteRule ^/(.*)     /something/$s

Why SQL Server throws Arithmetic overflow error converting int to data type numeric?

Numeric defines the TOTAL number of digits, and then the number after the decimal.

A numeric(3,2) can only hold up to 9.99.

window.location.href and window.open () methods in JavaScript

window.open is a method; you can open new window, and can customize it. window.location.href is just a property of the current window.

Simple calculations for working with lat/lon and km distance?

Thanks Jim Lewis for his great answer and I would like to illustrate this solution by my function in Swift:

func getRandomLocation(forLocation location: CLLocation, withOffsetKM offset: Double) -> CLLocation {
        let latDistance = (Double(arc4random()) / Double(UInt32.max)) * offset * 2.0 - offset
        let longDistanceMax = sqrt(offset * offset - latDistance * latDistance)
        let longDistance = (Double(arc4random()) / Double(UInt32.max)) * longDistanceMax * 2.0 - longDistanceMax

        let lat: CLLocationDegrees = location.coordinate.latitude + latDistance / 110.574
        let lng: CLLocationDegrees = location.coordinate.longitude + longDistance / (111.320 * cos(lat / .pi / 180))
        return CLLocation(latitude: lat, longitude: lng)
    }

In this function to convert distance I use following formulas:

latDistance / 110.574
longDistance / (111.320 * cos(lat / .pi / 180))

Using Python Requests: Sessions, Cookies, and POST

I don't know how stubhub's api works, but generally it should look like this:

s = requests.Session()
data = {"login":"my_login", "password":"my_password"}
url = "http://example.net/login"
r = s.post(url, data=data)

Now your session contains cookies provided by login form. To access cookies of this session simply use

s.cookies

Any further actions like another requests will have this cookie

Unknown SSL protocol error in connection

I was getting that behind a corporate proxy.

Solved by:

git config http.sslVerify "false"

Using Default Arguments in a Function

You can't do this directly, but a little code fiddling makes it possible to emulate.

function foo($blah, $x = false, $y = false) {
  if (!$x) $x = "some value";
  if (!$y) $y = "some other value";

  // code
}

Checking cin input stream produces an integer

You could use :

int a = 12;
if (a>0 || a<0){
cout << "Your text"<<endl;
}

I'm pretty sure it works.

How to compare two tags with git?

$ git diff tag1 tag2

or show log between them:

$ git log tag1..tag2

sometimes it may be convenient to see only the list of files that were changed:

$ git diff tag1 tag2 --stat

and then look at the differences for some particular file:

$ git diff tag1 tag2 -- some/file/name

A tag is only a reference to the latest commit 'on that tag', so that you are doing a diff on the commits between them.

(Make sure to do git pull --tags first)

Also, a good reference: http://learn.github.com/p/diff.html

git checkout master error: the following untracked working tree files would be overwritten by checkout

Try git checkout -f master.

-f or --force

Source: https://www.kernel.org/pub/software/scm/git/docs/git-checkout.html

When switching branches, proceed even if the index or the working tree differs from HEAD. This is used to throw away local changes.

When checking out paths from the index, do not fail upon unmerged entries; instead, unmerged entries are ignored.

Fatal error: Class 'PHPMailer' not found

I had a number of errors similar to this. Make sure your setFrom email address is valid in $mail->setFrom()

How to print GETDATE() in SQL Server with milliseconds in time?

This is equivalent to new Date().getTime() in JavaScript :

Use the below statement to get the time in seconds.

SELECT  cast(DATEDIFF(s, '1970-01-01 00:00:00.000', '2016-12-09 16:22:17.897' ) as bigint)

Use the below statement to get the time in milliseconds.

SELECT  cast(DATEDIFF(s, '1970-01-01 00:00:00.000', '2016-12-09 16:22:17.897' ) as bigint)  * 1000

Regular Expression with wildcards to match any character

Without knowing the exact regex implementation you're making use of, I can only give general advice. (The syntax I will be perl as that's what I know, some languages will require tweaking)

Looking at ABC: (z) jan 02 1999 \n

  • The first thing to match is ABC: So using our regex is /ABC:/

  • You say ABC is always at the start of the string so /^ABC/ will ensure that ABC is at the start of the string.

  • You can match spaces with the \s (note the case) directive. With all directives you can match one or more with + (or 0 or more with *)

  • You need to escape the usage of ( and ) as it's a reserved character. so \(\)

  • You can match any non space or newline character with .

  • You can match anything at all with .* but you need to be careful you're not too greedy and capture everything.

So in order to capture what you've asked. I would use /^ABC:\s*\(.+?\)\s*(.+)$/

Which I read as:

Begins with ABC:

May have some spaces

has (

has some characters

has )

may have some spaces

then capture everything until the end of the line (which is $).

I highly recommend keeping a copy of the following laying about http://www.cheatography.com/davechild/cheat-sheets/regular-expressions/

jQuery get input value after keypress

Just use a timeout to make your call; the timeout will be called when the event stack is finished (i.e. after the default event is called)

$("body").on('keydown', 'input[type=tel]', function (e) {
    setTimeout(() => {
        formatPhone(e)
    }, 0)
});

DateTime vs DateTimeOffset

From Microsoft:

These uses for DateTimeOffset values are much more common than those for DateTime values. As a result, DateTimeOffset should be considered the default date and time type for application development.

source: "Choosing Between DateTime, DateTimeOffset, TimeSpan, and TimeZoneInfo", MSDN

We use DateTimeOffset for nearly everything as our application deals with particular points in time (e.g. when a record was created/updated). As a side note, we use DATETIMEOFFSET in SQL Server 2008 as well.

I see DateTime as being useful when you want to deal with dates only, times only, or deal with either in a generic sense. For example, if you have an alarm that you want to go off every day at 7 am, you could store that in a DateTime utilizing a DateTimeKind of Unspecified because you want it to go off at 7am regardless of DST. But if you want to represent the history of alarm occurrences, you would use DateTimeOffset.

Use caution when using a mix of DateTimeOffset and DateTime especially when assigning and comparing between the types. Also, only compare DateTime instances that are the same DateTimeKind because DateTime ignores timezone offset when comparing.

CSS background opacity with rgba not working in IE 8

Create a png which is larger than 1x1 pixel (thanks thirtydot), and which matches the transparency of your background.

EDIT : to fall back for IE6+ support, you can specify bkgd chunk for the png, this is a color which will replace the true alpha transparency if it is not supported. You can fix it with gimp eg.

jQuery & CSS - Remove/Add display:none

i'd suggest adding a class to display/hide elements:

.hide { display:none; }

and then use jquery's .toggleClass() to show/hide the element:

$(".news").toggleClass("hide");

TortoiseGit save user authentication / credentials

[open git settings (TortoiseGit ? Settings ? Git)][1]

[In GIt: click to edit global .gitconfig][2]

config username and password

jQuery scrollTop not working in Chrome but working in Firefox

 $("html, body").animate({ scrollTop: 0 }, "slow");

This CSS conflict with scroll to top so take care of this

 html, body {
         overflow-x: hidden;        
    }

Excel VBA Copy a Range into a New Workbook

Modify to suit your specifics, or make more generic as needed:

Private Sub CopyItOver()
  Set NewBook = Workbooks.Add
  Workbooks("Whatever.xlsx").Worksheets("output").Range("A1:K10").Copy
  NewBook.Worksheets("Sheet1").Range("A1").PasteSpecial (xlPasteValues)
  NewBook.SaveAs FileName:=NewBook.Worksheets("Sheet1").Range("E3").Value
End Sub

Python circular importing?

For those of you who, like me, come to this issue from Django, you should know that the docs provide a solution: https://docs.djangoproject.com/en/1.10/ref/models/fields/#foreignkey

"...To refer to models defined in another application, you can explicitly specify a model with the full application label. For example, if the Manufacturer model above is defined in another application called production, you’d need to use:

class Car(models.Model):
    manufacturer = models.ForeignKey(
        'production.Manufacturer',
        on_delete=models.CASCADE,
)

This sort of reference can be useful when resolving circular import dependencies between two applications...."

'printf' vs. 'cout' in C++

I'm surprised that everyone in this question claims that std::cout is way better than printf, even if the question just asked for differences. Now, there is a difference - std::cout is C++, and printf is C (however, you can use it in C++, just like almost anything else from C). Now, I'll be honest here; both printf and std::cout have their advantages.

Real differences

Extensibility

std::cout is extensible. I know that people will say that printf is extensible too, but such extension is not mentioned in the C standard (so you would have to use non-standard features - but not even common non-standard feature exists), and such extensions are one letter (so it's easy to conflict with an already-existing format).

Unlike printf, std::cout depends completely on operator overloading, so there is no issue with custom formats - all you do is define a subroutine taking std::ostream as the first argument and your type as second. As such, there are no namespace problems - as long you have a class (which isn't limited to one character), you can have working std::ostream overloading for it.

However, I doubt that many people would want to extend ostream (to be honest, I rarely saw such extensions, even if they are easy to make). However, it's here if you need it.

Syntax

As it could be easily noticed, both printf and std::cout use different syntax. printf uses standard function syntax using pattern string and variable-length argument lists. Actually, printf is a reason why C has them - printf formats are too complex to be usable without them. However, std::cout uses a different API - the operator << API that returns itself.

Generally, that means the C version will be shorter, but in most cases it won't matter. The difference is noticeable when you print many arguments. If you have to write something like Error 2: File not found., assuming error number, and its description is placeholder, the code would look like this. Both examples work identically (well, sort of, std::endl actually flushes the buffer).

printf("Error %d: %s.\n", id, errors[id]);
std::cout << "Error " << id << ": " << errors[id] << "." << std::endl;

While this doesn't appear too crazy (it's just two times longer), things get more crazy when you actually format arguments, instead of just printing them. For example, printing of something like 0x0424 is just crazy. This is caused by std::cout mixing state and actual values. I never saw a language where something like std::setfill would be a type (other than C++, of course). printf clearly separates arguments and actual type. I really would prefer to maintain the printf version of it (even if it looks kind of cryptic) compared to iostream version of it (as it contains too much noise).

printf("0x%04x\n", 0x424);
std::cout << "0x" << std::hex << std::setfill('0') << std::setw(4) << 0x424 << std::endl;

Translation

This is where the real advantage of printf lies. The printf format string is well... a string. That makes it really easy to translate, compared to operator << abuse of iostream. Assuming that the gettext() function translates, and you want to show Error 2: File not found., the code to get translation of the previously shown format string would look like this:

printf(gettext("Error %d: %s.\n"), id, errors[id]);

Now, let's assume that we translate to Fictionish, where the error number is after the description. The translated string would look like %2$s oru %1$d.\n. Now, how to do it in C++? Well, I have no idea. I guess you can make fake iostream which constructs printf that you can pass to gettext, or something, for purposes of translation. Of course, $ is not C standard, but it's so common that it's safe to use in my opinion.

Not having to remember/look-up specific integer type syntax

C has lots of integer types, and so does C++. std::cout handles all types for you, while printf requires specific syntax depending on an integer type (there are non-integer types, but the only non-integer type you will use in practice with printf is const char * (C string, can be obtained using to_c method of std::string)). For instance, to print size_t, you need to use %zd, while int64_t will require using %"PRId64". The tables are available at http://en.cppreference.com/w/cpp/io/c/fprintf and http://en.cppreference.com/w/cpp/types/integer.

You can't print the NUL byte, \0

Because printf uses C strings as opposed to C++ strings, it cannot print NUL byte without specific tricks. In certain cases it's possible to use %c with '\0' as an argument, although that's clearly a hack.

Differences nobody cares about

Performance

Update: It turns out that iostream is so slow that it's usually slower than your hard drive (if you redirect your program to file). Disabling synchronization with stdio may help, if you need to output lots of data. If the performance is a real concern (as opposed to writing several lines to STDOUT), just use printf.

Everyone thinks that they care about performance, but nobody bothers to measure it. My answer is that I/O is bottleneck anyway, no matter if you use printf or iostream. I think that printf could be faster from a quick look into assembly (compiled with clang using the -O3 compiler option). Assuming my error example, printf example does way fewer calls than the cout example. This is int main with printf:

main:                                   @ @main
@ BB#0:
        push    {lr}
        ldr     r0, .LCPI0_0
        ldr     r2, .LCPI0_1
        mov     r1, #2
        bl      printf
        mov     r0, #0
        pop     {lr}
        mov     pc, lr
        .align  2
@ BB#1:

You can easily notice that two strings, and 2 (number) are pushed as printf arguments. That's about it; there is nothing else. For comparison, this is iostream compiled to assembly. No, there is no inlining; every single operator << call means another call with another set of arguments.

main:                                   @ @main
@ BB#0:
        push    {r4, r5, lr}
        ldr     r4, .LCPI0_0
        ldr     r1, .LCPI0_1
        mov     r2, #6
        mov     r3, #0
        mov     r0, r4
        bl      _ZSt16__ostream_insertIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_PKS3_l
        mov     r0, r4
        mov     r1, #2
        bl      _ZNSolsEi
        ldr     r1, .LCPI0_2
        mov     r2, #2
        mov     r3, #0
        mov     r4, r0
        bl      _ZSt16__ostream_insertIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_PKS3_l
        ldr     r1, .LCPI0_3
        mov     r0, r4
        mov     r2, #14
        mov     r3, #0
        bl      _ZSt16__ostream_insertIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_PKS3_l
        ldr     r1, .LCPI0_4
        mov     r0, r4
        mov     r2, #1
        mov     r3, #0
        bl      _ZSt16__ostream_insertIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_PKS3_l
        ldr     r0, [r4]
        sub     r0, r0, #24
        ldr     r0, [r0]
        add     r0, r0, r4
        ldr     r5, [r0, #240]
        cmp     r5, #0
        beq     .LBB0_5
@ BB#1:                                 @ %_ZSt13__check_facetISt5ctypeIcEERKT_PS3_.exit
        ldrb    r0, [r5, #28]
        cmp     r0, #0
        beq     .LBB0_3
@ BB#2:
        ldrb    r0, [r5, #39]
        b       .LBB0_4
.LBB0_3:
        mov     r0, r5
        bl      _ZNKSt5ctypeIcE13_M_widen_initEv
        ldr     r0, [r5]
        mov     r1, #10
        ldr     r2, [r0, #24]
        mov     r0, r5
        mov     lr, pc
        mov     pc, r2
.LBB0_4:                                @ %_ZNKSt5ctypeIcE5widenEc.exit
        lsl     r0, r0, #24
        asr     r1, r0, #24
        mov     r0, r4
        bl      _ZNSo3putEc
        bl      _ZNSo5flushEv
        mov     r0, #0
        pop     {r4, r5, lr}
        mov     pc, lr
.LBB0_5:
        bl      _ZSt16__throw_bad_castv
        .align  2
@ BB#6:

However, to be honest, this means nothing, as I/O is the bottleneck anyway. I just wanted to show that iostream is not faster because it's "type safe". Most C implementations implement printf formats using computed goto, so the printf is as fast as it can be, even without compiler being aware of printf (not that they aren't - some compilers can optimize printf in certain cases - constant string ending with \n is usually optimized to puts).

Inheritance

I don't know why you would want to inherit ostream, but I don't care. It's possible with FILE too.

class MyFile : public FILE {}

Type safety

True, variable length argument lists have no safety, but that doesn't matter, as popular C compilers can detect problems with printf format string if you enable warnings. In fact, Clang can do that without enabling warnings.

$ cat safety.c

#include <stdio.h>

int main(void) {
    printf("String: %s\n", 42);
    return 0;
}

$ clang safety.c

safety.c:4:28: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
    printf("String: %s\n", 42);
                    ~~     ^~
                    %d
1 warning generated.
$ gcc -Wall safety.c
safety.c: In function ‘main’:
safety.c:4:5: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘int’ [-Wformat=]
     printf("String: %s\n", 42);
     ^

How to check if all of the following items are in a list?

An example of how to do this using a lambda expression would be:

issublist = lambda x, y: 0 in [_ in x for _ in y]

validation of input text field in html using javascript

If you are not using jQuery then I would simply write a validation method that you can be fired when the form is submitted. The method can validate the text fields to make sure that they are not empty or the default value. The method will return a bool value and if it is false you can fire off your alert and assign classes to highlight the fields that did not pass validation.

HTML:

<form name="form1" method="" action="" onsubmit="return validateForm(this)">
<input type="text" name="name" value="Name"/><br />
<input type="text" name="addressLine01" value="Address Line 1"/><br />
<input type="submit"/>
</form>

JavaScript:

function validateForm(form) {

    var nameField = form.name;
    var addressLine01 = form.addressLine01;

    if (isNotEmpty(nameField)) {
        if(isNotEmpty(addressLine01)) {
            return true;
        {
    {
    return false;
}

function isNotEmpty(field) {

    var fieldData = field.value;

    if (fieldData.length == 0 || fieldData == "" || fieldData == fieldData) {

        field.className = "FieldError"; //Classs to highlight error
        alert("Please correct the errors in order to continue.");
        return false;
    } else {

        field.className = "FieldOk"; //Resets field back to default
        return true; //Submits form
    }
}

The validateForm method assigns the elements you want to validate and then in this case calls the isNotEmpty method to validate if the field is empty or has not been changed from the default value. it continuously calls the inNotEmpty method until it returns a value of true or if the conditional fails for that field it will return false.

Give this a shot and let me know if it helps or if you have any questions. of course you can write additional custom methods to validate numbers only, email address, valid URL, etc.

If you use jQuery at all I would look into trying out the jQuery Validation plug-in. I have been using it for my last few projects and it is pretty nice. Check it out if you get a chance. http://docs.jquery.com/Plugins/Validation

SQL select max(date) and corresponding value

Each MAX function is evaluated individually. So MAX(CompletedDate) will return the value of the latest CompletedDate column and MAX(Notes) will return the maximum (i.e. alphabeticaly highest) value.

You need to structure your query differently to get what you want. This question had actually already been asked and answered several times, so I won't repeat it:

How to find the record in a table that contains the maximum value?

Finding the record with maximum value in SQL

Convert Month Number to Month Name Function in SQL

To convert month number to month name, try the below

declare @month smallint = 1
select DateName(mm,DATEADD(mm,@month - 1,0))

How to open my files in data_folder with pandas using relative path?

Keeping things tidy with f-strings:

import os
import pandas as pd

data_files = '../data_folder/'
csv_name = 'data.csv'

pd.read_csv(f"{data_files}{csv_name}")

Best way to randomize an array with .NET

Random r = new Random();
List<string> list = new List(originalArray);
List<string> randomStrings = new List();

while(list.Count > 0)
{
int i = r.Random(list.Count);
randomStrings.Add(list[i]);
list.RemoveAt(i);
}

Does Java support default parameter values?

No, but you can very easily emulate them. What in C++ was:

public: void myFunction(int a, int b=5, string c="test") { ... }

In Java, it will be an overloaded function:

public void myFunction(int a, int b, string c) { ... }

public void myFunction(int a, int b) {
    myFunction(a, b, "test");
}

public void myFunction(int a) {
    myFunction(a, 5);
}

Earlier was mentioned, that default parameters caused ambiguous cases in function overloading. That is simply not true, we can see in the case of the C++: yes, maybe it can create ambiguous cases, but these problem can be easily handled. It simply wasn't developed in Java, probably because the creators wanted a much simpler language as C++ was - if they had right, is another question. But most of us don't think he uses Java because of its simplicity.

Why use HttpClient for Synchronous Connection

In my case the accepted answer did not work. I was calling the API from an MVC application which had no async actions.

This is how I managed to make it work:

private static readonly TaskFactory _myTaskFactory = new TaskFactory(CancellationToken.None, TaskCreationOptions.None, TaskContinuationOptions.None, TaskScheduler.Default);
public static T RunSync<T>(Func<Task<T>> func)
    {           
        CultureInfo cultureUi = CultureInfo.CurrentUICulture;
        CultureInfo culture = CultureInfo.CurrentCulture;
        return _myTaskFactory.StartNew<Task<T>>(delegate
        {
            Thread.CurrentThread.CurrentCulture = culture;
            Thread.CurrentThread.CurrentUICulture = cultureUi;
            return func();
        }).Unwrap<T>().GetAwaiter().GetResult();
    }

Then I called it like this:

Helper.RunSync(new Func<Task<ReturnTypeGoesHere>>(async () => await AsyncCallGoesHere(myparameter)));

Compute row average in pandas

You can specify a new column. You also need to compute the mean along the rows, so use axis=1.

df['mean'] = df.mean(axis=1)
>>> df
       Y1961      Y1962      Y1963      Y1964      Y1965 Region       mean
0  82.567307  83.104757  83.183700  83.030338  82.831958     US  82.943612
1   2.699372   2.610110   2.587919   2.696451   2.846247     US   2.688020
2  14.131355  13.690028  13.599516  13.649176  13.649046     US  13.743824
3   0.048589   0.046982   0.046583   0.046225   0.051750     US   0.048026
4   0.553377   0.548123   0.582282   0.577811   0.620999     US   0.576518

How to prevent IFRAME from redirecting top-level window

In my case I want the user to visit the inner page so that server will see their ip as a visitor. If I use the php proxy technique I think that the inner page will see my server ip as a visitor so it is not good. The only solution I got so far is wilth onbeforeunload. Put this on your page:

<script type="text/javascript">
    window.onbeforeunload = function () {                       
         return "This will end your session";
    }
</script>

This works both in firefox and ie, thats what I tested for. you will find versions using something like evt.return(whatever) crap... that doesn't work in firefox.

mysql update query with sub query

Thanks, I didn't have the idea of an UPDATE with INNER JOIN.

In the original query, the mistake was to name the subquery, which must return a value and can't therefore be aliased.

UPDATE Competition
SET Competition.NumberOfTeams =
(SELECT count(*) -- no column alias
  FROM PicksPoints
  WHERE UserCompetitionID is not NULL
  -- put the join condition INSIDE the subquery :
  AND CompetitionID =  Competition.CompetitionID
  group by CompetitionID
) -- no table alias

should do the trick for every record of Competition.

To be noticed :

The effect is NOT EXACTLY the same as the query proposed by mellamokb, which won't update Competition records with no corresponding PickPoints.

Since SELECT id, COUNT(*) GROUP BY id will only count for existing values of ids,

whereas a SELECT COUNT(*) will always return a value, being 0 if no records are selected.

This may, or may not, be a problem for you.

0-aware version of mellamokb query would be :

Update Competition as C
LEFT join (
  select CompetitionId, count(*) as NumberOfTeams
  from PicksPoints as p
  where UserCompetitionID is not NULL
  group by CompetitionID
) as A on C.CompetitionID = A.CompetitionID
set C.NumberOfTeams = IFNULL(A.NumberOfTeams, 0)

In other words, if no corresponding PickPoints are found, set Competition.NumberOfTeams to zero.

The import javax.servlet can't be resolved

Add to pom.xml

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
</dependency>

jQuery limit to 2 decimal places

You could use a variable to make the calculation and use toFixed when you set the #diskamountUnit element value:

var amount = $("#disk").slider("value") * 1.60;
$("#diskamountUnit").val('$' + amount.toFixed(2));

You can also do that in one step, in the val method call but IMO the first way is more readable:

$("#diskamountUnit").val('$' + ($("#disk").slider("value") * 1.60).toFixed(2));

Combination of async function + await + setTimeout

Since Node 7.6, you can combine the functions promisify function from the utils module with setTimeout() .

Node.js

const sleep = require('util').promisify(setTimeout)

Javascript

const sleep = m => new Promise(r => setTimeout(r, m))

Usage

(async () => {
    console.time("Slept for")
    await sleep(3000)
    console.timeEnd("Slept for")
})()

Dynamically adding HTML form field using jQuery

You can add any type of HTML with methods like append and appendTo (among others):

jQuery manipulation methods

Example:

$('form#someform').append('<input type="text" name="something" id="something" />');

Sending GET request with Authentication headers using restTemplate

You're not missing anything. RestTemplate#exchange(..) is the appropriate method to use to set request headers.

Here's an example (with POST, but just change that to GET and use the entity you want).

Here's another example.

Note that with a GET, your request entity doesn't have to contain anything (unless your API expects it, but that would go against the HTTP spec). It can be an empty String.

Why is SQL server throwing this error: Cannot insert the value NULL into column 'id'?

As id is PK it MUST be unique and not null. If you do not mention any field in the fields list for insert it'll be supposed to be null or default value. Set identity (i.e. autoincrement) for this field if you do not want to set it manualy every time.

Can't use WAMP , port 80 is used by IIS 7.5

This happens to me once: I uninstalled the IIS, and the port 80 still was used. Well the problem was that also I had the Report Service of the Sql Server 2012 installed, so I stopped that service and the problems solves.

See Stop Or Uninstall IIS for running Wamp Server (Apache) on default port (:80) question for more details.

Hope this helps some body, as it help to me.

How do I get the dialer to open with phone number displayed?

Pretty late on the answer, but if you have a TextView that you're showing the phone number in, then you don't need to deal with intents at all, you can just use the XML attribute android:autoLink="phone" and the OS will automatically initiate an ACTION_DIAL Intent.

Responding with a JSON object in Node.js (converting object/array to JSON string)

in express there may be application-scoped JSON formatters.

after looking at express\lib\response.js, I'm using this routine:

function writeJsonPToRes(app, req, res, obj) {
    var replacer = app.get('json replacer');
    var spaces = app.get('json spaces');
    res.set('Content-Type', 'application/json');
    var partOfResponse = JSON.stringify(obj, replacer, spaces)
        .replace(/\u2028/g, '\\u2028')
        .replace(/\u2029/g, '\\u2029');
    var callback = req.query[app.get('jsonp callback name')];
    if (callback) {
        if (Array.isArray(callback)) callback = callback[0];
        res.set('Content-Type', 'text/javascript');
        var cb = callback.replace(/[^\[\]\w$.]/g, '');
        partOfResponse = 'typeof ' + cb + ' === \'function\' && ' + cb + '(' + partOfResponse + ');\n';
    }
    res.write(partOfResponse);
}

Android: Pass data(extras) to a fragment

I prefer Serializable = no boilerplate code. For passing data to other Fragments or Activities the speed difference to a Parcelable does not matter.

I would also always provide a helper method for a Fragment or Activity, this way you always know, what data has to be passed. Here an example for your ListMusicFragment:

private static final String EXTRA_MUSIC_LIST = "music_list";

public static ListMusicFragment createInstance(List<Music> music) {
    ListMusicFragment fragment = new ListMusicFragment();
    Bundle bundle = new Bundle();
    bundle.putSerializable(EXTRA_MUSIC_LIST, music);
    fragment.setArguments(bundle);
    return fragment;
}

@Override
public View onCreateView(...) { 
    ...
    Bundle bundle = intent.getArguments();
    List<Music> musicList = (List<Music>)bundle.getSerializable(EXTRA_MUSIC_LIST);
    ...
}

Error during installing HAXM, VT-X not working

For Windows 10:

First of all, install the intelhaxm-android.exe located in the folder SDK\extras\Intel\Hardware_Accelerated_Execution_Manager if it gives error during installation then try these solution.

  1. First all enable the virtualization from bios setting. To enable this, restart the computer, when the computer started then press Esc, then select the F2 if the manufacturer is dell.

  2. Even if you have enabled the Virtualization (VT) in BIOS settings, some antivirus options prevent HAXM installation.

    For example: In Avast antivirus under Settings (parameters) tab > Troubleshooting (depannage), you should uncheck "Enable Hardware-assisted Virtualization" ("activer l'assistance a la virtualisation").

    Now restart your computer and re-install the Intel's HAXM, which can be found under SDK\extras\intel\Hardware_Accelerated_Execution_Manager. You can also manually download the standalone HAXM installer from Intel's website.

  3. Check that hyper-v is disabled. To disable it, go to the control panel then select the Programs --> Program and Features--> Turn windows Feature on or off (located on left side), then find the HYPER-V, uncheck the check box and restart the computer and try to install the hxm again.

  4. Go to properties of "This PC" by right clicking on it, then select the advanced system setting (located on left side) then in Advance (tab) under performance click the setting button, then select the Data Execution Prevention (tab), then select this option: "turn on the DEP for all programs and services except those I select" and restart the computer and try to install the hxm.

Solution 3 works for me.

How to execute the start script with Nodemon

Add this to script object from your project's package.json file


    "start":"nodemon index.js"

It should be like this


    "scripts": {
        "start":"nodemon index.js"
    }

Print all but the first three columns

A solution that does not add extra leading or trailing whitespace:

awk '{ for(i=4; i<NF; i++) printf "%s",$i OFS; if(NF) printf "%s",$NF; printf ORS}'

### Example ###
$ echo '1 2 3 4 5 6 7' |
  awk '{for(i=4;i<NF;i++)printf"%s",$i OFS;if(NF)printf"%s",$NF;printf ORS}' |
  tr ' ' '-'
4-5-6-7

Sudo_O proposes an elegant improvement using the ternary operator NF?ORS:OFS

$ echo '1 2 3 4 5 6 7' |
  awk '{ for(i=4; i<=NF; i++) printf "%s",$i (i==NF?ORS:OFS) }' |
  tr ' ' '-'
4-5-6-7

EdMorton gives a solution preserving original whitespaces between fields:

$ echo '1   2 3 4   5    6 7' |
  awk '{ sub(/([^ ]+ +){3}/,"") }1' |
  tr ' ' '-'
4---5----6-7

BinaryZebra also provides two awesome solutions:
(these solutions even preserve trailing spaces from original string)

$ echo -e ' 1   2\t \t3     4   5   6 7 \t 8\t ' |
  awk -v n=3 '{ for ( i=1; i<=n; i++) { sub("^["FS"]*[^"FS"]+["FS"]+","",$0);} } 1 ' |
  sed 's/ /./g;s/\t/->/g;s/^/"/;s/$/"/'
"4...5...6.7.->.8->."

$ echo -e ' 1   2\t \t3     4   5   6 7 \t 8\t ' |
  awk -v n=3 '{ print gensub("["FS"]*([^"FS"]+["FS"]+){"n"}","",1); }' |
  sed 's/ /./g;s/\t/->/g;s/^/"/;s/$/"/'
"4...5...6.7.->.8->."

The solution given by larsr in the comments is almost correct:

$ echo '1 2 3 4 5 6 7' | 
  awk '{for (i=3;i<=NF;i++) $(i-2)=$i; NF=NF-2; print $0}' | tr  ' ' '-'
3-4-5-6-7

This is the fixed and parametrized version of larsr solution:

$ echo '1 2 3 4 5 6 7' | 
  awk '{for(i=n;i<=NF;i++)$(i-(n-1))=$i;NF=NF-(n-1);print $0}' n=4 | tr ' ' '-'
4-5-6-7

All other answers before Sep-2013 are nice but add extra spaces:

javascript variable reference/alias

To some degree this is possible, you can create an alias to a variable using closures:

Function.prototype.toString = function() {
    return this();
}

var x = 1;
var y = function() { return x }
x++;
alert(y); // prints 2, no need for () because of toString redefinition 

Java - Check if JTextField is empty or not

you can use isEmpty() or isBlank() methods regarding what you need.


Returns true if, and only if, length() is 0.

this.name.getText().isEmpty();

Returns true if the string is empty or contains only white space codepoints, otherwise false

this.name.getText().isBlank();

Is it possible to move/rename files in Git and maintain their history?

git log --follow [file]

will show you the history through renames.

Get SELECT's value and text in jQuery

$("#yourdropdownid option:selected").text(); // selected option text
$("#yourdropdownid").val(); // selected option value

How do I set the classpath in NetBeans?

Maven

The Answer by Bhesh Gurung is correct… unless your NetBeans project is Maven based.

Dependency

Under Maven, you add a "dependency". A dependency is a description of a library (its name & version number) you want to use from your code.

Or a dependency could be a description of a library which another library needs ("depends on"). Maven automatically handles this chain, libraries that need other libraries that then need other libraries and so on. For the mathematical-minded, perhaps the phrase "Maven resolves the transitive dependencies" makes sense.

Repository

Maven gets this related-ness information, and the libraries themselves from a Maven repository. A repository is basically an online database and collection of download files (the dependency library).

Easy to Use

Adding a dependency to a Maven-based project is really quite easy. That is the whole point to Maven, to make managing dependent libraries easy and to make building them into your project easy. To get started with adding a dependency, see this Question, Adding dependencies in Maven Netbeans and my Answer with screenshot.

enter image description here

Why do you need to invoke an anonymous function on the same line?

The code you show,

(function (msg){alert(msg)});
('SO');

consist of two statements. The first is an expression which yields a function object (which will then be garbage collected because it is not saved). The second is an expression which yields a string. To apply the function to the string, you either need to pass the string as an argument to the function when it is created (which you also show above), or you will need to actually store the function in a variable, so that you can apply it at a later time, at your leisure. Like so:

var f = (function (msg){alert(msg)});
f('SO');

Note that by storing an anonymous function (a lambda function) in a variable, your are effectively giving it a name. Hence you may just as well define a regular function:

function f(msg) {alert(msg)};
f('SO');

rsync - mkstemp failed: Permission denied (13)

run in root access ssh chould solve this problem

or chmod 0777 /dir/to/be/backedup/

or chown username:user /dir/to/be/backedup/

Where do I find the current C or C++ standard documents?

The text of a draft of the ANSI C standard (aka C.89) is available online. This was standardized by the ANSI committee prior to acceptance by the ISO C Standard (C.90), so the numbering of the sections differ (ANSI sections 2 through 4 correspond roughly to ISO sections 5 through 7), although the content is (supposed to be) largely identical.

What is this Javascript "require"?

You know how when you are running JavaScript in the browser, you have access to variables like "window" or Math? You do not have to declare these variables, they have been written for you to use whenever you want.

Well, when you are running a file in the Node.js environment, there is a variable that you can use. It is called "module" It is an object. It has a property called "exports." And it works like this:

In a file that we will name example.js, you write:

example.js

module.exports = "some code";

Now, you want this string "some code" in another file.

We will name the other file otherFile.js

In this file, you write:

otherFile.js

let str = require('./example.js')

That require() statement goes to the file that you put inside of it, finds whatever data is stored on the module.exports property. The let str = ... part of your code means that whatever that require statement returns is stored to the str variable.

So, in this example, the end-result is that in otherFile.js you now have this:

let string = "some code";

  • or -

let str = ('./example.js').module.exports

Note:

the file-name that is written inside of the require statement: If it is a local file, it should be the file-path to example.js. Also, the .js extension is added by default, so I didn't have to write it.

You do something similar when requiring node.js libraries, such as Express. In the express.js file, there is an object named 'module', with a property named 'exports'.

So, it looks something like along these lines, under the hood (I am somewhat of a beginner so some of these details might not be exact, but it's to show the concept:

express.js

module.exports = function() {
    //It returns an object with all of the server methods
    return {
        listen: function(port){},
        get: function(route, function(req, res){}){}
     }
}

If you are requiring a module, it looks like this: const moduleName = require("module-name");

If you are requiring a local file, it looks like this: const localFile = require("./path/to/local-file");

(notice the ./ at the beginning of the file name)


Also note that by default, the export is an object .. eg module.exports = {} So, you can write module.exports.myfunction = () => {} before assigning a value to the module.exports. But you can also replace the object by writing module.exports = "I am not an object anymore."

Override and reset CSS style: auto or none don't work

I ended up using Javascript to perfect everything.

My JS fiddle: https://jsfiddle.net/QEpJH/612/

HTML:

<div class="container">
    <img src="http://placekitten.com/240/300">
</div>

<h3 style="clear: both;">Full Size Image - For Reference</h3>
<img src="http://placekitten.com/240/300">

CSS:

.container {
    background-color:#000;
    width:100px;
    height:200px;

    display:flex;
    justify-content:center;
    align-items:center;
    overflow:hidden;

}

JS:

$(".container").each(function(){
    var divH = $(this).height()
    var divW = $(this).width()
    var imgH = $(this).children("img").height();
    var imgW = $(this).children("img").width();

    if ( (imgW/imgH) < (divW/divH)) { 
        $(this).addClass("1");
        var newW = $(this).width();
        var newH = (newW/imgW) * imgH;
        $(this).children("img").width(newW); 
        $(this).children("img").height(newH); 
    } else {
        $(this).addClass("2");
        var newH = $(this).height();
        var newW = (newH/imgH) * imgW;
        $(this).children("img").width(newW); 
        $(this).children("img").height(newH); 
    }
})

MySQL Insert into multiple tables? (Database normalization?)

try this

$sql= " INSERT INTO users (username, password) VALUES('test', 'test') ";
mysql_query($sql);
$user_id= mysql_insert_id();
if(!empty($user_id) {

$sql=INSERT INTO profiles (userid, bio, homepage) VALUES($user_id,'Hello world!', 'http://www.stackoverflow.com');
/* or 
 $sql=INSERT INTO profiles (userid, bio, homepage) VALUES(LAST_INSERT_ID(),'Hello   world!', 'http://www.stackoverflow.com'); */
 mysql_query($sql);
};

References
PHP
MYSQL

What is the behavior difference between return-path, reply-to and from?

Another way to think about Return-Path vs Reply-To is to compare it to snail mail.

When you send an envelope in the mail, you specify a return address. If the recipient does not exist or refuses your mail, the postmaster returns the envelope back to the return address. For email, the return address is the Return-Path.

Inside of the envelope might be a letter and inside of the letter it may direct the recipient to "Send correspondence to example address". For email, the example address is the Reply-To.

In essence, a Postage Return Address is comparable to SMTP's Return-Path header and SMTP's Reply-To header is similar to the replying instructions contained in a letter.

$_POST vs. $_SERVER['REQUEST_METHOD'] == 'POST'

It checks whether the page has been called through POST (as opposed to GET, HEAD, etc). When you type a URL in the menu bar, the page is called through GET. However, when you submit a form with method="post" the action page is called with POST.

C - gettimeofday for computing time?

Your curtime variable holds the number of seconds since the epoch. If you get one before and one after, the later one minus the earlier one is the elapsed time in seconds. You can subtract time_t values just fine.

How to list physical disks?

Might want to include the old A: and B: drives as you never know who might be using them! I got tired of USB drives bumping my two SDHC drives that are just for Readyboost. I had been assigning them to High letters Z: Y: with a utility that will assign drive letters to devices as you wish. I wondered.... Can I make a Readyboost drive letter A: ? YES! Can I put my second SDHC drive letter as B: ? YES!

I've used Floppy Drives back in the day, never thought that A: or B: would come in handy for Readyboost.

My point is, don't assume A: & B: will not be used by anyone for anything You might even find the old SUBST command being used!

Logging with Retrofit 2

For those who need high level logging in Retrofit, use the interceptor like this

public static class LoggingInterceptor implements Interceptor {
    @Override public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        long t1 = System.nanoTime();
        String requestLog = String.format("Sending request %s on %s%n%s",
                request.url(), chain.connection(), request.headers());
        //YLog.d(String.format("Sending request %s on %s%n%s",
        //        request.url(), chain.connection(), request.headers()));
        if(request.method().compareToIgnoreCase("post")==0){
            requestLog ="\n"+requestLog+"\n"+bodyToString(request);
        }
        Log.d("TAG","request"+"\n"+requestLog);

        Response response = chain.proceed(request);
        long t2 = System.nanoTime();

        String responseLog = String.format("Received response for %s in %.1fms%n%s",
                response.request().url(), (t2 - t1) / 1e6d, response.headers());

        String bodyString = response.body().string();

        Log.d("TAG","response"+"\n"+responseLog+"\n"+bodyString);

        return response.newBuilder()
                .body(ResponseBody.create(response.body().contentType(), bodyString))
                .build();
        //return response;
    }
}

public static String bodyToString(final Request request) {
    try {
        final Request copy = request.newBuilder().build();
        final Buffer buffer = new Buffer();
        copy.body().writeTo(buffer);
        return buffer.readUtf8();
    } catch (final IOException e) {
        return "did not work";
    }
}`

Courtesy: https://github.com/square/retrofit/issues/1072#

Why, Fatal error: Class 'PHPUnit_Framework_TestCase' not found in ...?

NOTICE: Command php bin/console generate:doctrine:crud also create TestController in src/Tests so it can throw error when you tried to start server if you don't have UnitTests. Remove the file fix it!

What is the difference between ManualResetEvent and AutoResetEvent in .NET?

Taken from C# 3.0 Nutshell book, by Joseph Albahari

Threading in C# - Free E-Book

A ManualResetEvent is a variation on AutoResetEvent. It differs in that it doesn't automatically reset after a thread is let through on a WaitOne call, and so functions like a gate: calling Set opens the gate, allowing any number of threads that WaitOne at the gate through; calling Reset closes the gate, causing, potentially, a queue of waiters to accumulate until its next opened.

One could simulate this functionality with a boolean "gateOpen" field (declared with the volatile keyword) in combination with "spin-sleeping" – repeatedly checking the flag, and then sleeping for a short period of time.

ManualResetEvents are sometimes used to signal that a particular operation is complete, or that a thread's completed initialization and is ready to perform work.

How does the SQL injection from the "Bobby Tables" XKCD comic work?

Say you naively wrote a student creation method like this:

void createStudent(String name) {
    database.execute("INSERT INTO students (name) VALUES ('" + name + "')");
}

And someone enters the name Robert'); DROP TABLE STUDENTS; --

What gets run on the database is this query:

INSERT INTO students (name) VALUES ('Robert'); DROP TABLE STUDENTS --')

The semicolon ends the insert command and starts another; the -- comments out the rest of the line. The DROP TABLE command is executed...

This is why bind parameters are a good thing.

Python datetime strptime() and strftime(): how to preserve the timezone information

Here is my answer in Python 2.7

Print current time with timezone

from datetime import datetime
import tzlocal  # pip install tzlocal

print datetime.now(tzlocal.get_localzone()).strftime("%Y-%m-%d %H:%M:%S %z")

Print current time with specific timezone

from datetime import datetime
import pytz # pip install pytz

print datetime.now(pytz.timezone('Asia/Taipei')).strftime("%Y-%m-%d %H:%M:%S %z")

It will print something like

2017-08-10 20:46:24 +0800

android image button

You can use the button :

1 - make the text empty

2 - set the background for it

+3 - you can use the selector to more useful and nice button


About the imagebutton you can set the image source and the background the same picture and it must be (*.png) when you do it you can make any design for the button

and for more beauty button use the selector //just Google it ;)

How can I import a database with MySQL from terminal?

If you are using sakila-db from mysql website, It's very easy on the Linux platform just follow the below-mentioned steps, After downloading the zip file of sakila-db, extract it. Now you will have two files, one is sakila-schema.sql and the other one is sakila-data.sql.


  1. Open terminal
  2. Enter command mysql -u root -p < sakila-schema.sql
  3. Enter command mysql -u root -p < sakila-data.sql
  4. Now enter command mysql -u root -p and enter your password, now you have entered into mysql system with default database.
  5. To use sakila database, use this command use sakila;
  6. To see tables in sakila-db, use show tables command

Please take care that extracted files are present in home directory.

Hiding a password in a python script (insecure obfuscation only)

Place the configuration information in a encrypted config file. Query this info in your code using an key. Place this key in a separate file per environment, and don't store it with your code.

How to handle calendar TimeZones using Java?

Date and Timestamp objects are timezone-oblivious: they represent a certain number of seconds since the epoch, without committing to a particular interpretation of that instant as hours and days. Timezones enter the picture only in GregorianCalendar (not directly needed for this task) and SimpleDateFormat, which need a timezone offset to convert between separate fields and Date (or long) values.

The OP's problem is right at the beginning of his processing: the user inputs hours, which are ambiguous, and they are interpreted in the local, non-GMT timezone; at this point the value is "6:12 EST", which can be easily printed as "11.12 GMT" or any other timezone but is never going to change to "6.12 GMT".

There is no way to make the SimpleDateFormat that parses "06:12" as "HH:MM" (defaulting to the local time zone) default to UTC instead; SimpleDateFormat is a bit too smart for its own good.

However, you can convince any SimpleDateFormat instance to use the right time zone if you put it explicitly in the input: just append a fixed string to the received (and adequately validated) "06:12" to parse "06:12 GMT" as "HH:MM z".

There is no need of explicit setting of GregorianCalendar fields or of retrieving and using timezone and daylight saving time offsets.

The real problem is segregating inputs that default to the local timezone, inputs that default to UTC, and inputs that really require an explicit timezone indication.

Rebase feature branch onto another feature branch

  1. Switch to Branch2

    git checkout Branch2
    
  2. Apply the current (Branch2) changes on top of the Branch1 changes, staying in Branch2:

    git rebase Branch1
    

Which would leave you with the desired result in Branch2:

a -- b -- c                      <-- Master
           \
            d -- e               <-- Branch1
           \
            d -- e -- f' -- g'   <-- Branch2

You can delete Branch1.

How to change XML Attribute

Mike; Everytime I need to modify an XML document I work it this way:

//Here is the variable with which you assign a new value to the attribute
string newValue = string.Empty;
XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(xmlFile);

XmlNode node = xmlDoc.SelectSingleNode("Root/Node/Element");
node.Attributes[0].Value = newValue;

xmlDoc.Save(xmlFile);

//xmlFile is the path of your file to be modified

I hope you find it useful

Why is using "for...in" for array iteration a bad idea?

In addition to the reasons given in other answers, you may not want to use the "for...in" structure if you need to do math with the counter variable because the loop iterates through the names of the object's properties and so the variable is a string.

For example,

for (var i=0; i<a.length; i++) {
    document.write(i + ', ' + typeof i + ', ' + i+1);
}

will write

0, number, 1
1, number, 2
...

whereas,

for (var ii in a) {
    document.write(i + ', ' + typeof i + ', ' + i+1);
}

will write

0, string, 01
1, string, 11
...

Of course, this can easily be overcome by including

ii = parseInt(ii);

in the loop, but the first structure is more direct.

java.lang.RuntimeException: Unable to start activity ComponentInfo

After trying few answers they are either not related to my project or , I have tried cleaning and rebuilding (https://stackoverflow.com/a/48760966/8463813). But it didn't work for me directly. I have compared it with older version of code, in which i observed some library files(jars and aars in External Libraries directory) are missing. Tried Invalidate Cache and Restart worked, which created all the libraries and working fine.

Jenkins could not run git

I had a similar problem finding the git executable on OS X.

I had to change my Path to Git executable to : /usr/local/git/bin/git

Might give that a shot if you are still stuck.

Java get String CompareTo as a comparator object

Regarding Nambari's answer there was a mistake. If you compare values using double equal sign == program will never reach compare method, unless someone will use new keyword to create String object which is not the best practice. This might be a bit better solution:

public int compare(String o1, String o2) {
        if (o1 == null && o2 == null){return 0;}
        if (o1 == null) { return -1;}
        if (o2 == null) { return 1;}
        return o1.compareTo(o2);
    }

P.S. Thanks for comments ;)

Remove or adapt border of frame of legend using matplotlib

One more related question, since it took me forever to find the answer:

How to make the legend background blank (i.e. transparent, not white):

legend = plt.legend()
legend.get_frame().set_facecolor('none')

Warning, you want 'none' (the string). None means the default color instead.

How to take column-slices of dataframe in pandas

You can slice along the columns of a DataFrame by referring to the names of each column in a list, like so:

data = pandas.DataFrame(np.random.rand(10,5), columns = list('abcde'))
data_ab = data[list('ab')]
data_cde = data[list('cde')]

How can I override the OnBeforeUnload dialog and replace it with my own?

You can detect which button (ok or cancel) pressed by user, because the onunload function called only when the user choise leaveing the page. Althoug in this funcion the possibilities is limited, because the DOM is being collapsed. You can run javascript, but the ajax POST doesn't do anything therefore you can't use this methode for automatic logout. But there is a solution for that. The window.open('logout.php') executed in the onunload funcion, so the user will logged out with a new window opening.

function onunload = (){
    window.open('logout.php');
}

This code called when user leave the page or close the active window and user logged out by 'logout.php'. The new window close immediately when logout php consist of code:

window.close();

Android checkbox style

Note: Using Android Support Library v22.1.0 and targeting API level 11 and up? Scroll down to the last update.


My application style is set to Theme.Holo which is dark and I would like the check boxes on my list view to be of style Theme.Holo.Light. I am not trying to create a custom style. The code below doesn't seem to work, nothing happens at all.

At first it may not be apparent why the system exhibits this behaviour, but when you actually look into the mechanics you can easily deduce it. Let me take you through it step by step.

First, let's take a look what the Widget.Holo.Light.CompoundButton.CheckBox style defines. To make things more clear, I've also added the 'regular' (non-light) style definition.

<style name="Widget.Holo.Light.CompoundButton.CheckBox" parent="Widget.CompoundButton.CheckBox" />

<style name="Widget.Holo.CompoundButton.CheckBox" parent="Widget.CompoundButton.CheckBox" />

As you can see, both are empty declarations that simply wrap Widget.CompoundButton.CheckBox in a different name. So let's look at that parent style.

<style name="Widget.CompoundButton.CheckBox">
    <item name="android:background">@android:drawable/btn_check_label_background</item>
    <item name="android:button">?android:attr/listChoiceIndicatorMultiple</item>
</style>

This style references both a background and button drawable. btn_check_label_background is simply a 9-patch and hence not very interesting with respect to this matter. However, ?android:attr/listChoiceIndicatorMultiple indicates that some attribute based on the current theme (this is important to realise) will determine the actual look of the CheckBox.

As listChoiceIndicatorMultiple is a theme attribute, you will find multiple declarations for it - one for each theme (or none if it gets inherited from a parent theme). This will look as follows (with other attributes omitted for clarity):

<style name="Theme">
    <item name="listChoiceIndicatorMultiple">@android:drawable/btn_check</item>
    ...
</style>

<style name="Theme.Holo">
    <item name="listChoiceIndicatorMultiple">@android:drawable/btn_check_holo_dark</item>
    ...
</style>

<style name="Theme.Holo.Light" parent="Theme.Light">
    <item name="listChoiceIndicatorMultiple">@android:drawable/btn_check_holo_light</item>
    ...
</style>

So this where the real magic happens: based on the theme's listChoiceIndicatorMultiple attribute, the actual appearance of the CheckBox is determined. The phenomenon you're seeing is now easily explained: since the appearance is theme-based (and not style-based, because that is merely an empty definition) and you're inheriting from Theme.Holo, you will always get the CheckBox appearance matching the theme.

Now, if you want to change your CheckBox's appearance to the Holo.Light version, you will need to take a copy of those resources, add them to your local assets and use a custom style to apply them.

As for your second question:

Also can you set styles to individual widgets if you set a style to the application?

Absolutely, and they will override any activity- or application-set styles.

Is there any way to set a theme(style with images) to the checkbox widget. (...) Is there anyway to use this selector: link?


Update:

Let me start with saying again that you're not supposed to rely on Android's internal resources. There's a reason you can't just access the internal namespace as you please.

However, a way to access system resources after all is by doing an id lookup by name. Consider the following code snippet:

int id = Resources.getSystem().getIdentifier("btn_check_holo_light", "drawable", "android");
((CheckBox) findViewById(R.id.checkbox)).setButtonDrawable(id);

The first line will actually return the resource id of the btn_check_holo_light drawable resource. Since we established earlier that this is the button selector that determines the look of the CheckBox, we can set it as 'button drawable' on the widget. The result is a CheckBox with the appearance of the Holo.Light version, no matter what theme/style you set on the application, activity or widget in xml. Since this sets only the button drawable, you will need to manually change other styling; e.g. with respect to the text appearance.

Below a screenshot showing the result. The top checkbox uses the method described above (I manually set the text colour to black in xml), while the second uses the default theme-based Holo styling (non-light, that is).

Screenshot showing the result


Update2:

With the introduction of Support Library v22.1.0, things have just gotten a lot easier! A quote from the release notes (my emphasis):

Lollipop added the ability to overwrite the theme at a view by view level by using the android:theme XML attribute - incredibly useful for things such as dark action bars on light activities. Now, AppCompat allows you to use android:theme for Toolbars (deprecating the app:theme used previously) and, even better, brings android:theme support to all views on API 11+ devices.

In other words: you can now apply a theme on a per-view basis, which makes solving the original problem a lot easier: just specify the theme you'd like to apply for the relevant view. I.e. in the context of the original question, compare the results of below:

<CheckBox
    ...
    android:theme="@android:style/Theme.Holo" />

<CheckBox
    ...
    android:theme="@android:style/Theme.Holo.Light" />

The first CheckBox is styled as if used in a dark theme, the second as if in a light theme, regardless of the actual theme set to your activity or application.

Of course you should no longer be using the Holo theme, but instead use Material.

Entity Framework : How do you refresh the model when the db changes?

Double click on the .edmx file then right_click anywhere on the screen and choose "Update Modle From DB". In the new window go to the "Refresh" tab and choose the changed table/view and click Finish.

Resizable table columns with jQuery

I've done my own jquery ui widget, just thinking if it's good enough.

https://github.com/OnekO/colresizable

How to erase the file contents of text file in Python?

Not a complete answer more of an extension to ondra's answer

When using truncate() ( my preferred method ) make sure your cursor is at the required position. When a new file is opened for reading - open('FILE_NAME','r') it's cursor is at 0 by default. But if you have parsed the file within your code, make sure to point at the beginning of the file again i.e truncate(0) By default truncate() truncates the contents of a file starting from the current cusror position.

A simple example

How to make Google Fonts work in IE?

It's all about trying all those answers, for me, nothing works except the next solution: Google font suggested

@import 'https://fonts.googleapis.com/css?family=Assistant';

But, I'm using here foreign language fonts, and it didn't work on IE11 only. I found out this solution that worked:

@import 'https://fonts.googleapis.com/css?family=Assistant&subset=hebrew';

Hope that save someone precious time

Column "invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause"

You can use case in update and SWAP as many as you want

update Table SET column=(case when is_row_1 then value_2 else value_1 end) where rule_to_match_swap_columns

SFTP in Python? (platform independent)

fsspec is a great option for this, it offers a filesystem like implementation of sftp.

from fsspec.implementations.sftp import SFTPFileSystem
fs = SFTPFileSystem(host=host, username=username, password=password)

# list a directory
fs.ls("/")

# open a file
with fs.open(file_name) as file:
    content = file.read()

Also worth noting that fsspec uses paramiko in the implementation.

How to load a UIView using a nib file created with Interface Builder

You can also use UIViewController's initWithNibName instead of loadNibNamed. It is simpler, I find.

UIViewController *aViewController = [[UIViewController alloc] initWithNibName:@"MySubView" bundle:nil];
[self.subview addSubview:aViewController.view];
[aViewController release];  // release the VC

Now you just have to create MySubView.xib and MySubView.h/m. In MySubView.xib set the File's Owner class to UIViewController and view class to MySubView.

You can position and size of the subview using the parent xib file.

How to set String's font size, style in Java using the Font class?

Font myFont = new Font("Serif", Font.BOLD, 12);, then use a setFont method on your components like

JButton b = new JButton("Hello World");
b.setFont(myFont);

How to get the first line of a file in a bash script?

head takes the first lines from a file, and the -n parameter can be used to specify how many lines should be extracted:

line=$(head -n 1 filename)

Using scanner.nextLine()

Rather than placing an extra scanner.nextLine() each time you want to read something, since it seems you want to accept each input on a new line, you might want to instead changing the delimiter to actually match only newlines (instead of any whitespace, as is the default)

import java.util.Scanner;

class ScannerTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        scanner.useDelimiter("\\n");

        System.out.print("Enter an index: ");
        int index = scanner.nextInt();

        System.out.print("Enter a sentence: ");
        String sentence = scanner.next();

        System.out.println("\nYour sentence: " + sentence);
        System.out.println("Your index: " + index);
    }
}

Thus, to read a line of input, you only need scanner.next() that has the same behavior delimiter-wise of next{Int, Double, ...}

The difference with the "nextLine() every time" approach, is that the latter will accept, as an index also <space>3, 3<space> and 3<space>whatever while the former only accepts 3 on a line on its own

Make file echo displaying "$PATH" string

In the manual for GNU make, they talk about this specific example when describing the value function:

The value function provides a way for you to use the value of a variable without having it expanded. Please note that this does not undo expansions which have already occurred; for example if you create a simply expanded variable its value is expanded during the definition; in that case the value function will return the same result as using the variable directly.

The syntax of the value function is:

 $(value variable)

Note that variable is the name of a variable; not a reference to that variable. Therefore you would not normally use a ‘$’ or parentheses when writing it. (You can, however, use a variable reference in the name if you want the name not to be a constant.)

The result of this function is a string containing the value of variable, without any expansion occurring. For example, in this makefile:

 FOO = $PATH

 all:
         @echo $(FOO)
         @echo $(value FOO)

The first output line would be ATH, since the “$P” would be expanded as a make variable, while the second output line would be the current value of your $PATH environment variable, since the value function avoided the expansion.

Error creating bean with name 'entityManagerFactory

Adding dependencies didn't fix the issue at my end.

The issue was happening at my end because of "additional" fields that are part of the "@Entity" class and don't exist in the database.

I removed the additional fields from the @Entity class and it worked.

Select tableview row programmatically

From reference documentation:

Calling this method does not cause the delegate to receive a tableView:willSelectRowAtIndexPath: or tableView:didSelectRowAtIndexPath: message, nor does it send UITableViewSelectionDidChangeNotification notifications to observers.

What I would do is:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [self doSomethingWithRowAtIndexPath:indexPath];
}

And then, from where you wanted to call selectRowAtIndexPath, you instead call doSomethingWithRowAtIndexPath. On top of that, you can additionally also call selectRowAtIndexPath if you want the UI feedback to happen.

Using print statements only to debug

A simple way to do this is to call a logging function:

DEBUG = True

def log(s):
    if DEBUG:
        print s

log("hello world")

Then you can change the value of DEBUG and run your code with or without logging.

The standard logging module has a more elaborate mechanism for this.

When to use Comparable and Comparator

Use Comparable if you want to define a default (natural) ordering behaviour of the object in question, a common practice is to use a technical or natural (database?) identifier of the object for this.

Use Comparator if you want to define an external controllable ordering behaviour, this can override the default ordering behaviour.

Postgresql SELECT if string contains

I personally prefer the simpler syntax of the ~ operator.

SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' ~ tag_name;

Worth reading through Difference between LIKE and ~ in Postgres to understand the difference. `

Where is my .vimrc file?

For whatever reason, these answers didn't quite work for me. This is what worked for me instead:

In Vim, the :version command gives you the paths of system and user vimrc and gvimrc files (among other things), and the output looks something like this:

 system vimrc file: "$VIM/vimrc"
   user vimrc file: "$HOME/.vimrc"
    user exrc file: "$HOME/.exrc"
system gvimrc file: "$VIM/gvimrc"
  user gvimrc file: "$HOME/.gvimrc"

The one you want is user vimrc file: "$HOME/.vimrc"

So to edit the file: vim $HOME/.vimrc

Source: Open vimrc file

How to prevent null values inside a Map and null fields inside a bean from getting serialized through Jackson

For Jackson versions < 2.0 use this annotation on the class being serialized:

@JsonSerialize(include=JsonSerialize.Inclusion.NON_NULL)

Read and write to binary files in C?

I'm quite happy with my "make a weak pin storage program" solution. Maybe it will help people who need a very simple binary file IO example to follow.

$ ls
WeakPin  my_pin_code.pin  weak_pin.c
$ ./WeakPin
Pin: 45 47 49 32
$ ./WeakPin 8 2
$ Need 4 ints to write a new pin!
$./WeakPin 8 2 99 49
Pin saved.
$ ./WeakPin
Pin: 8 2 99 49
$
$ cat weak_pin.c
// a program to save and read 4-digit pin codes in binary format

#include <stdio.h>
#include <stdlib.h>

#define PIN_FILE "my_pin_code.pin"

typedef struct { unsigned short a, b, c, d; } PinCode;


int main(int argc, const char** argv)
{
    if (argc > 1)  // create pin
    {
        if (argc != 5)
        {
            printf("Need 4 ints to write a new pin!\n");
            return -1;
        }
        unsigned short _a = atoi(argv[1]);
        unsigned short _b = atoi(argv[2]);
        unsigned short _c = atoi(argv[3]);
        unsigned short _d = atoi(argv[4]);
        PinCode pc;
        pc.a = _a; pc.b = _b; pc.c = _c; pc.d = _d;
        FILE *f = fopen(PIN_FILE, "wb");  // create and/or overwrite
        if (!f)
        {
            printf("Error in creating file. Aborting.\n");
            return -2;
        }

        // write one PinCode object pc to the file *f
        fwrite(&pc, sizeof(PinCode), 1, f);  

        fclose(f);
        printf("Pin saved.\n");
        return 0;
    }

    // else read existing pin
    FILE *f = fopen(PIN_FILE, "rb");
    if (!f)
    {
        printf("Error in reading file. Abort.\n");
        return -3;
    }
    PinCode pc;
    fread(&pc, sizeof(PinCode), 1, f);
    fclose(f);

    printf("Pin: ");
    printf("%hu ", pc.a);
    printf("%hu ", pc.b);
    printf("%hu ", pc.c);
    printf("%hu\n", pc.d);
    return 0;
}
$

SQL Server Text type vs. varchar data type

There has been some major changes in ms 2008 -> Might be worth considering the following article when making a decisions on what data type to use. http://msdn.microsoft.com/en-us/library/ms143432.aspx

Bytes per

  1. varchar(max), varbinary(max), xml, text, or image column 2^31-1 2^31-1
  2. nvarchar(max) column 2^30-1 2^30-1

Matching an optional substring in a regex

(\d+)\s+(\(.*?\))?\s?Z

Note the escaped parentheses, and the ? (zero or once) quantifiers. Any of the groups you don't want to capture can be (?: non-capture groups).

I agree about the spaces. \s is a better option there. I also changed the quantifier to insure there are digits at the beginning. As far as newlines, that would depend on context: if the file is parsed line by line it won't be a problem. Another option is to anchor the start and end of the line (add a ^ at the front and a $ at the end).

Window.open and pass parameters by post method

Instead of writing a form into the new window (which is tricky to get correct, with encoding of values in the HTML code), just open an empty window and post a form to it.

Example:

<form id="TheForm" method="post" action="test.asp" target="TheWindow">
<input type="hidden" name="something" value="something" />
<input type="hidden" name="more" value="something" />
<input type="hidden" name="other" value="something" />
</form>

<script type="text/javascript">
window.open('', 'TheWindow');
document.getElementById('TheForm').submit();
</script>

Edit:

To set the values in the form dynamically, you can do like this:

function openWindowWithPost(something, additional, misc) {
  var f = document.getElementById('TheForm');
  f.something.value = something;
  f.more.value = additional;
  f.other.value = misc;
  window.open('', 'TheWindow');
  f.submit();
}

To post the form you call the function with the values, like openWindowWithPost('a','b','c');.

Note: I varied the parameter names in relation to the form names to show that they don't have to be the same. Usually you would keep them similar to each other to make it simpler to track the values.

How can Perl's print add a newline by default?

If Perl 5.10+ is not an option, here is a quick and dirty approximation. It's not exactly the same, since say has some magic when its first arg is a handle, but for printing to STDOUT:

sub say {print @_, "\n"}

say 'hello';

How to remove a build from itunes connect?

Dang this is hard. Here is what I did to reject/delete/replace my ios build before it was released. The app was approved how ever I found found a bug I wanted to fix before releasing

  1. I set release to "manual" and saved
  2. I tried to create and app release
  3. got an error message something like "you can only have one release at a time"
  4. where the save button was there was not an option to cancel release
  5. the version of the app is not marked "developer rejected" with a red dot

To replace the bad build I did the following

  1. if you click on the "+ version or platform" to create a new version you will not be be able to create a new iOS version
  2. you need to upload a new build
  3. in your rejected app, select the new build
  4. save
  5. submit for review

Copy multiple files from one directory to another from Linux shell

You can use brace expansion in bash:

cp /home/ankur/folder/{file1,abc,xyz} /path/to/target

g++ undefined reference to typeinfo

One possible reason is because you are declaring a virtual function without defining it.

When you declare it without defining it in the same compilation unit, you're indicating that it's defined somewhere else - this means the linker phase will try to find it in one of the other compilation units (or libraries).

An example of defining the virtual function is:

virtual void fn() { /* insert code here */ }

In this case, you are attaching a definition to the declaration, which means the linker doesn't need to resolve it later.

The line

virtual void fn();

declares fn() without defining it and will cause the error message you asked about.

It's very similar to the code:

extern int i;
int *pi = &i;

which states that the integer i is declared in another compilation unit which must be resolved at link time (otherwise pi can't be set to it's address).

How to generate a QR Code for an Android application?

Maybe this old topic but i found this library is very helpful and easy to use

QRGen

example for using it in android

 Bitmap myBitmap = QRCode.from("www.example.org").bitmap();
ImageView myImage = (ImageView) findViewById(R.id.imageView);
myImage.setImageBitmap(myBitmap);

How can I change the color of pagination dots of UIPageControl?

myView.superview.tintColor = [UIColor colorWithRed:1.0f  
                                      green:1.0f blue:1.0f alpha:1.0f];

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

Understanding Looper Threads

A java Thread a unit of execution which was designed to perform a task in its run() method & terminate after that: enter image description here

But in Android there are many use cases where we need to keep a Thread alive and wait for user inputs/events for eg. UI thread aka Main Thread.

Main thread in Android is a Java thread which is first started by JVM at the launch of an app and keeps on running till the user choose to close it or encounters unhandled exception.

When an application is launched, the system creates a thread of execution for the application, called "main." This thread is very important because it is in charge of dispatching events to the appropriate user interface widgets, including drawing events.

enter image description here

Now point to note here is although main thread is Java thread yet it keeps on listening to user events and draw 60 fps frames on screen and still it wont die after each cycle. how is it so?

The answer is Looper Class: Looper is a class which is used to keep a thread alive and manage a message queue to execute tasks on that thread.

Threads by default do not have a message loop associated with them but you can assign one by calling Looper.prepare() in the run method and then call the Looper.loop().

Purpose of Looper is to keep a Thread alive and wait for next cycle of input Message object to perform computation which otherwise will get destroyed after first cycle of execution.

If you want to dig deeper how Looper manage Message object queue then you can have a look at source code of Looperclass:

https://github.com/aosp-mirror/platform_frameworks_base/blob/master/core/java/android/os/Looper.java

Below is an example of how you can create a Looper Thread and communicate with Activity class using LocalBroadcast

class LooperThread : Thread() {

    // sendMessage success result on UI
    private fun sendServerResult(result: String) {
        val resultIntent = Intent(ServerService.ACTION)
        resultIntent.putExtra(ServerService.RESULT_CODE, Activity.RESULT_OK)
        resultIntent.putExtra(ServerService.RESULT_VALUE, result)
        LocalBroadcastManager.getInstance(AppController.getAppController()).sendBroadcast(resultIntent)
    }

    override fun run() {
        val looperIsNotPreparedInCurrentThread = Looper.myLooper() == null

        // Prepare Looper if not already prepared
        if (looperIsNotPreparedInCurrentThread) {
            Looper.prepare()
        }

        // Create a handler to handle messaged from Activity
        handler = Handler(Handler.Callback { message ->
            // Messages sent to Looper thread will be visible here
            Log.e(TAG, "Received Message" + message.data.toString())

            //message from Activity
            val result = message.data.getString(MainActivity.BUNDLE_KEY)

            // Send Result Back to activity
            sendServerResult(result)
            true
        })

        // Keep on looping till new messages arrive
        if (looperIsNotPreparedInCurrentThread) {
            Looper.loop()
        }
    }

    //Create and send a new  message to looper
    fun sendMessage(messageToSend: String) {
        //Create and post a new message to handler
        handler!!.sendMessage(createMessage(messageToSend))
    }


    // Bundle Data in message object
    private fun createMessage(messageToSend: String): Message {
        val message = Message()
        val bundle = Bundle()
        bundle.putString(MainActivity.BUNDLE_KEY, messageToSend)
        message.data = bundle
        return message
    }

    companion object {
        var handler: Handler? = null // in Android Handler should be static or leaks might occur
        private val TAG = javaClass.simpleName

    }
}

Usage:

 class MainActivity : AppCompatActivity() {

    private var looperThread: LooperThread? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // start looper thread
        startLooperThread()

        // Send messages to Looper Thread
        sendMessage.setOnClickListener {

            // send random messages to looper thread
            val messageToSend = "" + Math.random()

            // post message
            looperThread!!.sendMessage(messageToSend)

        }   
    }

    override fun onResume() {
        super.onResume()

        //Register to Server Service callback
        val filterServer = IntentFilter(ServerService.ACTION)
        LocalBroadcastManager.getInstance(this).registerReceiver(serverReceiver, filterServer)

    }

    override fun onPause() {
        super.onPause()

        //Stop Server service callbacks
     LocalBroadcastManager.getInstance(this).unregisterReceiver(serverReceiver)
    }


    // Define the callback for what to do when data is received
    private val serverReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context, intent: Intent) {
            val resultCode = intent.getIntExtra(ServerService.RESULT_CODE, Activity.RESULT_CANCELED)
            if (resultCode == Activity.RESULT_OK) {
                val resultValue = intent.getStringExtra(ServerService.RESULT_VALUE)
                Log.e(MainActivity.TAG, "Server result : $resultValue")

                serverOutput.text =
                        (serverOutput.text.toString()
                                + "\n"
                                + "Received : " + resultValue)

                serverScrollView.post( { serverScrollView.fullScroll(View.FOCUS_DOWN) })
            }
        }
    }

    private fun startLooperThread() {

        // create and start a new LooperThread
        looperThread = LooperThread()
        looperThread!!.name = "Main Looper Thread"
        looperThread!!.start()

    }

    companion object {
        val BUNDLE_KEY = "handlerMsgBundle"
        private val TAG = javaClass.simpleName
    }
}

Can we use Async task or Intent Services instead?

  • Async tasks are designed to perform a short operation in background and give progres & results on UI thread. Async tasks have limits like you cant create more than 128 Async tasks and ThreadPoolExecutor will allow only upto 5 Async tasks.

  • IntentServices are also designed to do background task for a little longer duration and you can use LocalBroadcast to communicate with Activity. But services get destroyed after task execution. If you want to keep it running for a long time than you need to do hecks like while(true){...}.

Other meaningful use cases for Looper Thread:

  • Used for 2 way socket communication where server keep on listening to Client socket and write back acknowledgment

  • Bitmap processing in background. Pass the image url to Looper thread and it will apply filter effects and store it in tempe rory location and then broadcast temp path of image.

Is there any advantage of using map over unordered_map in case of trivial keys?

If you want to compare the speed of your std::map and std::unordered_map implementations, you could use Google's sparsehash project which has a time_hash_map program to time them. For example, with gcc 4.4.2 on an x86_64 Linux system

$ ./time_hash_map
TR1 UNORDERED_MAP (4 byte objects, 10000000 iterations):
map_grow              126.1 ns  (27427396 hashes, 40000000 copies)  290.9 MB
map_predict/grow       67.4 ns  (10000000 hashes, 40000000 copies)  232.8 MB
map_replace            22.3 ns  (37427396 hashes, 40000000 copies)
map_fetch              16.3 ns  (37427396 hashes, 40000000 copies)
map_fetch_empty         9.8 ns  (10000000 hashes,        0 copies)
map_remove             49.1 ns  (37427396 hashes, 40000000 copies)
map_toggle             86.1 ns  (20000000 hashes, 40000000 copies)

STANDARD MAP (4 byte objects, 10000000 iterations):
map_grow              225.3 ns  (       0 hashes, 20000000 copies)  462.4 MB
map_predict/grow      225.1 ns  (       0 hashes, 20000000 copies)  462.6 MB
map_replace           151.2 ns  (       0 hashes, 20000000 copies)
map_fetch             156.0 ns  (       0 hashes, 20000000 copies)
map_fetch_empty         1.4 ns  (       0 hashes,        0 copies)
map_remove            141.0 ns  (       0 hashes, 20000000 copies)
map_toggle             67.3 ns  (       0 hashes, 20000000 copies)

Handling ExecuteScalar() when no results are returned

/* Select some int which does not exist */
int x = ((int)(SQL_Cmd.ExecuteScalar() ?? 0));

Qt c++ aggregate 'std::stringstream ss' has incomplete type and cannot be defined

Like it's written up there, you forget to type #include <sstream>

#include <sstream>
using namespace std;

QString Stats_Manager::convertInt(int num)
{
   stringstream ss;
   ss << num;
   return ss.str();
}

You can also use some other ways to convert int to string, like

char numstr[21]; // enough to hold all numbers up to 64-bits
sprintf(numstr, "%d", age);
result = name + numstr;

check this!