Programs & Examples On #System.web.abstractions

The 'packages' element is not declared

Change the node to and create a file, packages.xsd, in the same folder (and include it in the project) with the following contents:

<?xml version="1.0" encoding="utf-8" ?>
<xs:schema xmlns:xs="" elementFormDefault="qualified"
      targetNamespace="urn:packages" xmlns="urn:packages">
  <xs:element name="packages">
        <xs:element name="package" maxOccurs="unbounded">
            <xs:attribute name="id" type="xs:string" use="required" />
            <xs:attribute name="version" type="xs:string" use="required" />
            <xs:attribute name="targetFramework" type="xs:string" use="optional" />
            <xs:attribute name="allowedVersions" type="xs:string" use="optional" />

Could not load file or assembly 'System.Web.Mvc'

We want to add it because we are making a class library that uses it.

For me it is here...

C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET MVC 4\Assemblies

Creating a simple configuration file and parser in C++

Why not trying something simple and human-readable, like JSON (or XML) ?

There are many pre-made open-source implementations of JSON (or XML) for C++ - I would use one of them.

And if you want something more "binary" - try BJSON or BSON :)

Fatal error: Call to undefined function mysql_connect() in C:\Apache\htdocs\test.php on line 2

I had the similar issue. I solved it the following way after a number of attempts to follow the pieces of advice in the forums. I am reposting the solution because it could be helpful for others.

I am running Windows 7 (Apache 2.2 & PHP 5.2.17 & MySQL 5.0.51a), the syntax in the file "httpd.conf" (C:\Program Files (x86)\Apache Software Foundation\Apache2.2\conf\httpd.conf) was sensitive to slashes. You can check if "php.ini" is read from the right directory. Just type in your browser "localhost/index.php". The code of index.php is the following:

<?php echo phpinfo(); ?>

There is the row (not far from the top) called "Loaded Configuration File". So, if there is nothing added, then the problem could be that your "php.ini" is not read, even you uncommented (extension=php_mysql.dll and extension=php_mysqli.dll). So, in order to make it work I did the following step. I needed to change from

PHPIniDir 'c:\PHP\'


PHPIniDir 'c:\PHP'

Pay the attention that the last slash disturbed everything!

Now the row "Loaded Configuration File" gets "C:\PHP\php.ini" after refreshing "localhost/index.php" (before I restarted Apache2.2) as well as mysql block is there. MySQL and PHP are working together!

grep without showing path/file:line

From the man page:

-h, --no-filename
    Suppress the prefixing of file names on output. This is the default when there
    is only one file (or only standard input) to search.

python: Change the scripts working directory to the script's own directory

Don't do this.

Your scripts and your data should not be mashed into one big directory. Put your code in some known location (site-packages or /var/opt/udi or something) separate from your data. Use good version control on your code to be sure that you have current and previous versions separated from each other so you can fall back to previous versions and test future versions.

Bottom line: Do not mingle code and data.

Data is precious. Code comes and goes.

Provide the working directory as a command-line argument value. You can provide a default as an environment variable. Don't deduce it (or guess at it)

Make it a required argument value and do this.

import sys
import os
working= os.environ.get("WORKING_DIRECTORY","/some/default")
if len(sys.argv) > 1: working = sys.argv[1]
os.chdir( working )

Do not "assume" a directory based on the location of your software. It will not work out well in the long run.

Alternative to header("Content-type: text/xml");

No. You can't send headers after they were sent. Try to use hooks in wordpress

How to get response using cURL in PHP

If anyone else comes across this, I'm adding another answer to provide the response code or other information that might be needed in the "response".

// init curl object        
$ch = curl_init();

// define options
$optArray = array(
    CURLOPT_URL => '',

// apply those options
curl_setopt_array($ch, $optArray);

// execute request and get response
$result = curl_exec($ch);

// also get the error and response code
$errors = curl_error($ch);
$response = curl_getinfo($ch, CURLINFO_HTTP_CODE);




string(0) ""

// change to
string(42) "Could not resolve host:"

How to get cumulative sum

Late answer but showing one more possibility...

Cumulative Sum generation can be more optimized with the CROSS APPLY logic.

Works better than the INNER JOIN & OVER Clause when analyzed the actual query plan ...

/* Create table & populate data */

) Tab

Query cost relative to the batch 17%
FROM     #TMP T1 
         CROSS APPLY ( 
         SELECT   SUM( AS CumSum 
         FROM     #TMP T2 
         WHERE >=
         ) T2

/* Using INNER JOIN 
Query cost relative to the batch 46%
         SUM( CumSum
FROM     #TMP T1
         INNER JOIN #TMP T2
                 ON > =

/* Using OVER clause
Query cost relative to the batch 37%
         SUM( OVER( PARTITION BY id)
FROM     #TMP T1

  id       CumSum
-------   ------- 
   1         1
   2         3
   3         6
   4         10
   5         15

What does localhost:8080 mean?

http://localhost:8080/web: localhost ( hostname ) is the machine name or IP address of the host server e.g Glassfish, Tomcat. 8080 ( port ) is the address of the port on which the host server is listening for requests.

http://localhost/web: localhost ( hostname ) is the machine name or IP address of the host server e.g Glassfish, Tomcat. host server listening to default port 80.

Java BigDecimal: Round to the nearest whole value

You want

round(new MathContext(0));  // or perhaps another math context with rounding mode HALF_UP

MAX function in where clause mysql

The syntax you have used is incorrect. The query should be something like:

SELECT column_name(s) FROM tablename WHERE id = (SELECT MAX(id) FROM tablename)

AttributeError: 'datetime' module has no attribute 'strptime'

I got the same problem and it is not the solution that you told. So I changed the "from datetime import datetime" to "import datetime". After that with the help of "datetime.datetime" I can get the whole modules correctly. I guess this is the correct answer to that question.

What is simplest way to read a file into String?

Sadly, no.

I agree that such frequent operation should have easier implementation than copying of input line by line in loop, but you'll have to either write helper method or use external library.

C/C++ line number

You should use the preprocessor macro __LINE__ and __FILE__. They are predefined macros and part of the C/C++ standard. During preprocessing, they are replaced respectively by a constant string holding an integer representing the current line number and by the current file name.

Others preprocessor variables :

  • __func__ : function name (this is part of C99, not all C++ compilers support it)
  • __DATE__ : a string of form "Mmm dd yyyy"
  • __TIME__ : a string of form "hh:mm:ss"

Your code will be :

  printf("Not logical value at line number %d in file %s\n", __LINE__, __FILE__);

how to merge 200 csv files in Python

As ghostdog74 said, but this time with headers:

# first file:
for line in open("sh1.csv"):
# now the rest:    
for num in range(2,201):
    f = open("sh"+str(num)+".csv") # skip the header
    for line in f:
    f.close() # not really needed

How to work offline with TFS

There are couple of little visual studio extensions for this purpose:

  1. For VS2010 & TFS 2010, try this
  2. For VS2012 & TFS 2010, use this

In case of TFS 2012, looks like there is no need for 'Go offline' extensions. I read something about a new feature called local workspace for the similar purpose.

Alternatively I had good success with Git-TF. All the goodness of git and when you are ready, you can push it to TFS.

Create a new txt file using VB.NET

You can try writing into the Documents folder. Here is a "debug" function I did for the debugging needs of my project:

Private Sub writeDebug(ByVal x As String)
    Dim path As String = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
    Dim FILE_NAME As String = path & "\mydebug.txt"
    If System.IO.File.Exists(FILE_NAME) = False Then
    End If
    Dim objWriter As New System.IO.StreamWriter(FILE_NAME, True)
End Sub

There are more standard folders you can access through the "SpecialFolder" object.

AVD Manager - Cannot Create Android Virtual Device

Try to create an AVD with the monitor.bat in the tools-folder, that worked out for me!

Get records of current month

Check the MySQL Datetime Functions:

Try this:

FROM tableA 
      MONTH(columnName) = MONTH(CURRENT_DATE());

How to turn on front flash light programmatically in Android?

There's different ways to access Camera Flash in different Android versions. Few APIs stopped working in Lollipop and then it got changed again in Marshmallow. To overcome this, I have created a simple library that I have been using in few of my projects and it's giving good results. It's still incomplete, but you can try to check the code and find the missing pieces. Here's the link - NoobCameraFlash.

If you just want to integrate in your code, you can use gradle for that. Here's the instructions (Taken directly from the Readme) -

Step 1. Add the JitPack repository to your build file. Add it in your root build.gradle at the end of repositories:

allprojects {
        repositories {
            maven { url "" }

Step 2. Add the dependency

dependencies {
        compile 'com.github.Abhi347:NoobCameraFlash:0.0.1'


Initialize the NoobCameraManager singleton.


You can optionally set the Log Level for debug logging. Logging uses LumberJack library. The default LogLevel is LogLevel.None

NoobCameraManager.getInstance().init(this, LogLevel.Verbose);

After that you just need to call the singleton to turn on or off the camera flash.


You have to take care of the runtime permissions to access Camera yourself, before initializing the NoobCameraManager. In version 0.1.2 or earlier we used to provide support for permissions directly from the library, but due to dependency on the Activity object, we have to remove it.

It's easy to toggle Flash too


Examples for string find in Python

If you want to search for the last instance of a string in a text, you can run rfind.


   print s.rfind('l')

output: 3

*no import needed

Complete syntax:

stringEx.rfind(substr, beg=0, end=len(stringEx))

Combining two expressions (Expression<Func<T, bool>>)

I think this works fine, isn't it ?

Func<T, bool> expr1 = (x => x.Att1 == "a");
Func<T, bool> expr2 = (x => x.Att2 == "b");
Func<T, bool> expr1ANDexpr2 = (x => expr1(x) && expr2(x));
Func<T, bool> expr1ORexpr2 = (x => expr1(x) || expr2(x));
Func<T, bool> NOTexpr1 = (x => !expr1(x));

Extension gd is missing from your system - laravel composer Update

If you are working in PHP version 5.* then you have to install

sudo apt-get install php5-gd

And if you are working in PHP version 7.* then you have to install

sudo apt-get install php7.0-gd

Hope it will work...

And if you are working in PHP version 7.2 then you have to install

sudo apt-get install php7.2-gd... it worked for me

jQuery: Performing synchronous AJAX requests

how remote is that url ? is it from the same domain ? the code looks okay

try this

$.get(remote_url, function(data) { remote = data; });
// or
remote = $.get(remote_url).responseText;

Get current value when change select option - Angular2

You can Use ngValue. ngValue passes sting and object both.

Pass as Object:

<select (change)="onItemChange($event.value)">
    <option *ngFor="#obj of arr" [ngValue]="obj.value">

Pass as String:

<select (change)="onItemChange($event.value)">
    <option *ngFor="#obj of arr" [ngValue]="obj">

Raw_Input() Is Not Defined

For Python 3.x, use input(). For Python 2.x, use raw_input(). Don't forget you can add a prompt string in your input() call to create one less print statement. input("GUESS THAT NUMBER!").

How can we run a test method with multiple parameters in MSTest?

It is unfortunately not supported in older versions of MSTest. Apparently there is an extensibility model and you can implement it yourself. Another option would be to use data-driven tests.

My personal opinion would be to just stick with NUnit though...

As of Visual Studio 2012, update 1, MSTest has a similar feature. See McAden's answer.

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

goto services and stop the "World Wide Web Publishing Service" after restart the wamp server. after that start the "World Wide Web Publishing Service"

MySQL date formats - difficulty Inserting a date

When using a string-typed variable in PHP containing a date, the variable must be enclosed in single quotes:

$NEW_DATE = '1997-07-15';
$sql = "INSERT INTO tbl (NEW_DATE, ...) VALUES ('$NEW_DATE', ...)";

What's the difference between ISO 8601 and RFC 3339 Date Formats?

RFC 3339 is mostly a profile of ISO 8601, but is actually inconsistent with it in borrowing the "-00:00" timezone specification from RFC 2822. This is described in the Wikipedia article.

how to install gcc on windows 7 machine?

EDIT Since not so recently by now, MinGW-w64 has "absorbed" one of the toolchain building projects. The downloads can be found here. The installer should work, and allow you to pick a version that you need.

Note the Qt SDK comes with the same toolchain. So if you are developing in Qt and using the SDK, just use the toolchain it comes with.

Another alternative that has up to date toolchains comes from... harhar... a Microsoft developer, none other than STL (Stephan T. Lavavej, isn't that a spot-on name for the maintainer of MSVC++ Standard Library!). You can find it here. It includes Boost.

Another option which is highly useful if you care for prebuilt dependencies is MSYS2, which provides a Unix shell (a Cygwin fork modified to work better with Windows pathnames and such), also provides a GCC. It usually lags a bit behind, but that is compensated for by its good package management system and stability. They also provide a functional Clang with libc++ if you care for such thing.

I leave the below for reference, but I strongly suggest against using, due to limitations detailed below. TDM-GCC (the MinGW-w64 version) provides some hacks that you may find useful in your specific situation, although I recommend using vanilla GCC at all times for maximum compatibility.

GCC for Windows is provided by two projects currently. They both provide a very own implementation of the Windows SDK (headers and libraries) which is necessary because GCC does not work with Visual Studio files.

  1. The older, which @Mat already pointed you to. They provide only a 32-bit compiler. See here for the downloads you need:

    • Binutils is the linker and resource compiler etc.
    • GCC is the compiler, and is split in core and language packages
    • GDB is the debugger.
    • runtime library is required only for
    • You might need to download mingw32-make seperately.
    • For support, you can try (don't expect friendly replies) [email protected]

    Alternatively, download mingw-get and use that.

  2. The newer mingw-w64, which as the name predicts, also provides a 64-bit variant, and in the future hopefully some ARM support. I use it and built toolchains with their CRT. Personal and auto builds are found under "Toolchains targetting Win32/64" here. They also provide Linux to Windows cross-compilers. I suggest you try a personal build first, they are more complete. Try mine (rubenvb) for GCC 4.6 to 4.8, or use sezero's for GCC 4.4 and 4.5. Both of us provide 32-bit and 64-bit native toolchains. These packages include everything listed above. I currently recommend the "MinGW-Builds" builds, as these are currently sanctioned as "official builds", and come with an installer (see above).

    For support, send an email to [email protected] or post on the forum via

Both projects have their files listed on sourceforge, and all you have to do is either run the installer (in case of or download a suitable zipped package and extract it (in the case of mingw-w64).

There are a lot of "non-official" toolchain builders, one of the most popular is TDM-GCC. They may use patches that break binary compatibility with official/unpatched toolchains, so be careful using them. It's best to use the official releases.

Grouping into interval of 5 minutes within a time range

I came across the same issue.

I found that it is easy to group by any minute interval is just dividing epoch by minutes in amount of seconds and then either rounding or using floor to get ride of the remainder. So if you want to get interval in 5 minutes you would use 300 seconds.

    SELECT COUNT(*) cnt, 
    to_timestamp(floor((extract('epoch' from timestamp_column) / 300 )) * 300) 
    AT TIME ZONE 'UTC' as interval_alias
    FROM TABLE_NAME GROUP BY interval_alias
interval_alias       cnt
-------------------  ----  
2010-11-16 10:30:00  2
2010-11-16 10:35:00  10
2010-11-16 10:45:00  8
2010-11-16 10:55:00  11 

This will return the data correctly group by the selected minutes interval; however, it will not return the intervals that don't contains any data. In order to get those empty intervals we can use the function generate_series.

    SELECT generate_series(MIN(date_trunc('hour',timestamp_column)),
    max(date_trunc('minute',timestamp_column)),'5m') as interval_alias FROM 


2010-11-16 10:30:00  
2010-11-16 10:35:00
2010-11-16 10:40:00   
2010-11-16 10:45:00
2010-11-16 10:50:00   
2010-11-16 10:55:00   

Now to get the result with interval with zero occurrences we just outer join both result sets.

    SELECT series.minute as interval,  coalesce(cnt.amnt,0) as count from 
       SELECT count(*) amnt,
       to_timestamp(floor((extract('epoch' from timestamp_column) / 300 )) * 300)
       AT TIME ZONE 'UTC' as interval_alias
       from TABLE_NAME  group by interval_alias
       ) cnt
       SELECT generate_series(min(date_trunc('hour',timestamp_column)),
       max(date_trunc('minute',timestamp_column)),'5m') as minute from TABLE_NAME 
       ) series
  on series.minute = cnt.interval_alias

The end result will include the series with all 5 minute intervals even those that have no values.

interval             count
-------------------  ----  
2010-11-16 10:30:00  2
2010-11-16 10:35:00  10
2010-11-16 10:40:00  0
2010-11-16 10:45:00  8
2010-11-16 10:50:00  0 
2010-11-16 10:55:00  11 

The interval can be easily changed by adjusting the last parameter of generate_series. In our case we use '5m' but it could be any interval we want.

Tooltip on image

I am set Tooltips On My Working Project That Is 100% Working

<!DOCTYPE html>_x000D_
.tooltip {_x000D_
  position: relative;_x000D_
  display: inline-block;_x000D_
  border-bottom: 1px dotted black;_x000D_
.tooltip .tooltiptext {_x000D_
  visibility: hidden;_x000D_
  width: 120px;_x000D_
  background-color: black;_x000D_
  color: #fff;_x000D_
  text-align: center;_x000D_
  border-radius: 6px;_x000D_
  padding: 5px 0;_x000D_
  /* Position the tooltip */_x000D_
  position: absolute;_x000D_
  z-index: 1;_x000D_
.tooltip:hover .tooltiptext {_x000D_
  visibility: visible;_x000D_
<body style="text-align:center;">_x000D_
<p>Move the mouse over the text below:</p>_x000D_
<div class="tooltip"><img class="size_of_img" src="" alt="Image 1" /><span class="tooltiptext">grewon.pdf</span></div>_x000D_
<p>Note that the position of the tooltip text isn't very good. Check More Position <a href="">GO</a></p>_x000D_

CSS transition when class removed

Basically set up your css like:

element {
  border: 1px solid #fff;      
  transition: border .5s linear;

element.saved {
  border: 1px solid transparent;

CSS: Background image and padding

You can just add the padding to tour block element and add background-origin style like so:

.block {
  position: relative;
  display: inline-block;
  padding: 10px 12px;
  border:1px solid #e5e5e5;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  background-origin: content-box;
  background-image: url(_your_image_);
  height: 14rem;
  width: 10rem;

You can check several

How to backup a local Git repository?

came to this question via google.

Here is what i did in the simplest way.

git checkout branch_to_clone

then create a new git branch from this branch

git checkout -b new_cloned_branch
Switched to branch 'new_cloned_branch'

come back to original branch and continue:

git checkout branch_to_clone

Assuming you screwed up and need to restore something from backup branch :

git checkout new_cloned_branch -- <filepath>  #notice the space before and after "--"

Best part if anything is screwed up, you can just delete the source branch and move back to backup branch!!

How to build a JSON array from mysql database

Just an update for Mysqli users :

$base= mysqli_connect($dbhost,  $dbuser, $dbpass, $dbbase);

if (mysqli_connect_errno()) 
  die('Could not connect: ' . mysql_error());

$return_arr = array();

if ($result = mysqli_query( $base, $sql )){
    while ($row = mysqli_fetch_assoc($result)) {
    $row_array['id'] = $row['id'];
    $row_array['col1'] = $row['col1'];
    $row_array['col2'] = $row['col2'];



echo json_encode($return_arr);

How to read fetch(PDO::FETCH_ASSOC);

Loop through the array like any other Associative Array:

while($data = $datas->fetch( PDO::FETCH_ASSOC )){ 
     print $data['title'].'<br>'; 


$resultset = $datas->fetchALL(PDO::FETCH_ASSOC);

echo '<pre>'.$resultset.'</pre>';

Disable building workspace process in Eclipse

if needed programmatic from a PDE or JDT code:

public static void setWorkspaceAutoBuild(boolean flag) throws CoreException 
IWorkspace workspace = ResourcesPlugin.getWorkspace();
final IWorkspaceDescription description = workspace.getDescription();

How to select the first row of each group?

Here you can do like this -

   val data = df.groupBy("Hour").agg(first("Hour").as("_1"),first("Category").as("Category"),first("TotalValue").as("TotalValue")).drop("Hour")


Most efficient way to concatenate strings?

The StringBuilder.Append() method is much better than using the + operator. But I've found that, when executing 1000 concatenations or less, String.Join() is even more efficient than StringBuilder.

StringBuilder sb = new StringBuilder();

The only problem with String.Join is that you have to concatenate the strings with a common delimiter.

Edit: as @ryanversaw pointed out, you can make the delimiter string.Empty.

string key = String.Join("_", new String[] 
{ "Customers_Contacts", customerID, database, SessionID });

How do I get the difference between two Dates in JavaScript?

Depending on your needs, this function will calculate the difference between the 2 days, and return a result in days decimal.

// This one returns a signed decimal. The sign indicates past or future.

this.getDateDiff = function(date1, date2) {
    return (date1.getTime() - date2.getTime()) / (1000 * 60 * 60 * 24);

// This one always returns a positive decimal. (Suggested by Koen below)

this.getDateDiff = function(date1, date2) {
    return Math.abs((date1.getTime() - date2.getTime()) / (1000 * 60 * 60 * 24));

SELECT max(x) is returning null; how can I make it return 0?

You can also use COALESCE ( expression [ ,...n ] ) - returns first non-null like:

FROM tbl

PG::ConnectionBad - could not connect to server: Connection refused

This issue comes when postgres doesn't shut down properly. Here is how I resolved this issue in three simple steps.

Step 1: Go to your postgres directory

Mac Users will find this in /usr/local/var/postgres, others might look at /usr/var/postgres/.

Step 2: Remove .pid file by running this command.


Step 3: Restart your server

Mac Users

brew services restart postgresql

Linux Users

sudo service postgresql restart

Finally restart your app and you are good to go.

Android Studio Gradle Configuration with name 'default' not found

In my case I was using Gradle files that work under Windows but failed on Linux. The include ':SomeProject' and compile project(':SomeProject') were case sensitive and were not found.

codes for ADD,EDIT,DELETE,SEARCH in vb2010

Have you googled about it - insert update delete access, there are lots of reference about this.

Insert Update Delete Navigation & Searching In Access Database Using VB.NET

  • Create Visual Basic 2010 Project: VB-Access
  • Assume that, we have a database file named data.mdb
  • Place the data.mdb file into ..\bin\Debug\ folder (Where the project executable file (.exe) is placed)

what could be the easier way to connect and manipulate the DB?
Use OleDBConnection class to make connection with DB

is it by using MS ACCESS 2003 or MS ACCESS 2007?
you can use any you want to use or your client will use on their machine.

it seems that you want to find some example of opereations fo the database. Here is an example of Access 2010 for your reference:

Example code snippet:

Imports System
Imports System.Data
Imports System.Data.OleDb

Public Class DBUtil

 Private connectionString As String

 Public Sub New()

  Dim con As New OleDb.OleDbConnection
  Dim dbProvider As String = "Provider=Microsoft.ace.oledb.12.0;"
  Dim dbSource = "Data Source=d:\DB\Database11.accdb"

  connectionString = dbProvider & dbSource

 End Sub

 Public Function GetCategories() As DataSet

  Dim query As String = "SELECT * FROM Categories"
  Dim cmd As New OleDbCommand(query)
  Return FillDataSet(cmd, "Categories")

 End Function

 Public SubUpdateCategories(ByVal name As String)
  Dim query As String = "update Categories set name = 'new2' where name = ?"
  Dim cmd As New OleDbCommand(query)
cmd.Parameters.AddWithValue("Name", name)
  Return FillDataSet(cmd, "Categories")

 End Sub

 Public Function GetItems() As DataSet

  Dim query As String = "SELECT * FROM Items"
  Dim cmd As New OleDbCommand(query)
  Return FillDataSet(cmd, "Items")

 End Function

 Public Function GetItems(ByVal categoryID As Integer) As DataSet

  'Create the command.
  Dim query As String = "SELECT * FROM Items WHERE Category_ID=?"
  Dim cmd As New OleDbCommand(query)
  cmd.Parameters.AddWithValue("category_ID", categoryID)

  'Fill the dataset.
  Return FillDataSet(cmd, "Items")

 End Function

 Public Sub AddCategory(ByVal name As String)

  Dim con As New OleDbConnection(connectionString)

  'Create the command.
  Dim insertSQL As String = "INSERT INTO Categories "
  insertSQL &= "VALUES(?)"
  Dim cmd As New OleDbCommand(insertSQL, con)
  cmd.Parameters.AddWithValue("Name", name)

  End Try

 End Sub

 Public Sub AddItem(ByVal title As String, ByVal description As String, _
    ByVal price As Decimal, ByVal categoryID As Integer)

  Dim con As New OleDbConnection(connectionString)

  'Create the command.
  Dim insertSQL As String = "INSERT INTO Items "
  insertSQL &= "(Title, Description, Price, Category_ID)"
  insertSQL &= "VALUES (?, ?, ?, ?)"
  Dim cmd As New OleDb.OleDbCommand(insertSQL, con)
  cmd.Parameters.AddWithValue("Title", title)
  cmd.Parameters.AddWithValue("Description", description)
  cmd.Parameters.AddWithValue("Price", price)
  cmd.Parameters.AddWithValue("CategoryID", categoryID)

  End Try

 End Sub

 Private Function FillDataSet(ByVal cmd As OleDbCommand, ByVal tableName As String) As DataSet

  Dim con As New OleDb.OleDbConnection
  Dim dbProvider As String = "Provider=Microsoft.ace.oledb.12.0;"
  Dim dbSource = "Data Source=D:\DB\Database11.accdb"

  connectionString = dbProvider & dbSource
  con.ConnectionString = connectionString
  cmd.Connection = con
  Dim adapter As New OleDbDataAdapter(cmd)
  Dim ds As New DataSet()

   adapter.Fill(ds, tableName)
  End Try
  Return ds

 End Function

End Class

Refer these links:
Insert, Update, Delete & Search Values in MS Access 2003 with VB.NET 2005
How Add new record ,Update record,Delete Records using Forms when Access as a back

Add 'x' number of hours to date

I use this , its working cool.

//set timezone

//set an date and time to work with
$start = '2014-06-01 14:00:00';

//display the converted time
echo date('Y-m-d H:i',strtotime('+1 hour +20 minutes',strtotime($start)));

Capture key press without placing an input element on the page?

jQuery also has an excellent implementation that's incredibly easy to use. Here's how you could implement this functionality across browsers:

    var checkWebkitandIE=(e.which==26 ? 1 : 0);
    var checkMoz=(e.which==122 && e.ctrlKey ? 1 : 0);

    if (checkWebkitandIE || checkMoz) $("body").append("<p>ctrl+z detected!</p>");

Tested in IE7,Firefox 3.6.3 & Chrome

Another way of doing this is to use the keydown event and track the event.keyCode. However, since jQuery normalizes keyCode and charCode using event.which, their spec recommends using event.which in a variety of situations:

if (e.keyCode==90 && e.ctrlKey)
    $("body").append("<p>ctrl+z detected!</p>");

Run a JAR file from the command line and specify classpath

You can do a Runtime.getRuntime.exec(command) to relaunch the jar including classpath with args.

Form submit with AJAX passing form data to PHP without page refresh

<div class="container">
       <div class="row">
        <div class="col-md-3 col-sm-6 col-xs-12"></div>enter code here
          <div class="col-md-6 col-sm-6 col-xs-12">
          <div class="msg"></div>
            <form method="post" class="frm" id="form1" onsubmit="">
               <div class="form-group">
               <input type="text" class="form-control" name="fname" id="fname" placeholder="enter your first neme" required>
           <!--><span class="sp"><?php// echo $f_err;?></span><!-->
        <div class="form-group">
               <input type="text" class="form-control" name="lname" id="lname" placeholder="enter your last neme" required>
              <!--><span class="sp"><?php// echo $l_err;?></span><!-->
              <div class="form-group">
               <input type="text" class="form-control" name="email" id="email" placeholder="enter your email Address" required>
              <!--><span class="sp"><?php// echo $e_err;?></span><!-->
             <div class="form-group">
               <input type="number" class="form-control" name="mno" id="mno" placeholder="enter your mobile number" required>
              <!--><span class="sp"><?php //echo $m_err;?></span><!-->
              <div class="form-group">
               <input type="password" class="form-control" name="pass" id="pass" pattern="(?=.*[a-z])(?=.*[A-Z]).{4,8}" placeholder="enter your Password" required>
              <!--><span class="sp"><?php //echo $p_err;?></span><!-->
              <div class="radio">
               &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="radio" value="male" name="gender" id="gender" checked>male<br>
               &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="radio" value="female" name="gender" id="gender">female<br>
               &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="radio" value="other" name="gender" id="gender">other<br>
                                         <!--><span class="sp"> <?php //echo $r_err;?></span><!-->
                <div class="checkbox">
                  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox" name="check" id="check" checked>I Agree Turms&Condition<br>
                   <!--><span class="sp"> <?php //echo $c_err;?></span><!-->
                 <input type="submit"  class="btn btn-warning" name="submit" id="submit">
             </form>enter code here

               <div class="col-md-3 col-sm-6 col-xs-12"></div>


Excel Reference To Current Cell

Inside tables you can use [@] which (unfortunately) Excel automatically expands to Table1[@] but it does work. (I'm using Excel 2010)

For example when having two columns [Change] and [Balance], putting this in the [Balance] column:

=OFFSET([@], -1, 0) + [Change]

Note of course that this depends on the order of the rows (just like most any other solution), so it's a bit fragile.

Could not install packages due to an EnvironmentError: [Errno 13]

I also had the same problem, I tried many different command lines, this one worked for me:


    conda install py-xgboost

That's what I got:

Collecting package metadata: done
Solving environment: done

## Package Plan ##

  environment location: /home/simplonco/anaconda3

  added / updated specs:
    - py-xgboost

The following packages will be downloaded:

    package                    |            build
    _py-xgboost-mutex-2.0      |            cpu_0           9 KB
    ca-certificates-2019.1.23  |                0         126 KB
    certifi-2018.11.29         |           py37_0         146 KB
    conda-4.6.2                |           py37_0         1.7 MB
    libxgboost-0.80            |       he6710b0_0         3.7 MB
    mkl-2019.1                 |              144       204.6 MB
    mkl_fft-1.0.10             |   py37ha843d7b_0         169 KB
    mkl_random-1.0.2           |   py37hd81dba3_0         405 KB
    numpy-1.15.4               |   py37h7e9f1db_0          47 KB
    numpy-base-1.15.4          |   py37hde5b4d6_0         4.2 MB
    py-xgboost-0.80            |   py37he6710b0_0         1.7 MB
    scikit-learn-0.20.2        |   py37hd81dba3_0         5.7 MB
    scipy-1.2.0                |   py37h7c811a0_0        17.7 MB
                                           Total:       240.0 MB

The following NEW packages will be INSTALLED:

  _py-xgboost-mutex  pkgs/main/linux-64::_py-xgboost-mutex-2.0-cpu_0
  libxgboost         pkgs/main/linux-64::libxgboost-0.80-he6710b0_0
  py-xgboost         pkgs/main/linux-64::py-xgboost-0.80-py37he6710b0_0

The following packages will be UPDATED:

  ca-certificates     anaconda::ca-certificates-2018.12.5-0 --> pkgs/main::ca-certificates-2019.1.23-0
  mkl                                            2019.0-118 --> 2019.1-144
  mkl_fft                              1.0.4-py37h4414c95_1 --> 1.0.10-py37ha843d7b_0
  mkl_random                           1.0.1-py37h4414c95_1 --> 1.0.2-py37hd81dba3_0
  numpy                               1.15.1-py37h1d66e8a_0 --> 1.15.4-py37h7e9f1db_0
  numpy-base                          1.15.1-py37h81de0dd_0 --> 1.15.4-py37hde5b4d6_0
  scikit-learn                        0.19.2-py37h4989274_0 --> 0.20.2-py37hd81dba3_0
  scipy                                1.1.0-py37hfa4b5c9_1 --> 1.2.0-py37h7c811a0_0

The following packages will be SUPERSEDED by a higher-priority channel:

  certifi                                          anaconda --> pkgs/main
  conda                                            anaconda --> pkgs/main
  openssl                anaconda::openssl-1.1.1-h7b6447c_0 --> pkgs/main::openssl-1.1.1a-h7b6447c_0

Proceed ([y]/n)? y

Downloading and Extracting Packages
libxgboost-0.80      | 3.7 MB    | ##################################### | 100% 
mkl_random-1.0.2     | 405 KB    | ##################################### | 100% 
certifi-2018.11.29   | 146 KB    | ##################################### | 100% 
ca-certificates-2019 | 126 KB    | ##################################### | 100% 
conda-4.6.2          | 1.7 MB    | ##################################### | 100% 
mkl-2019.1           | 204.6 MB  | ##################################### | 100% 
mkl_fft-1.0.10       | 169 KB    | ##################################### | 100% 
numpy-1.15.4         | 47 KB     | ##################################### | 100% 
scipy-1.2.0          | 17.7 MB   | ##################################### | 100% 
scikit-learn-0.20.2  | 5.7 MB    | ##################################### | 100% 
py-xgboost-0.80      | 1.7 MB    | ##################################### | 100% 
_py-xgboost-mutex-2. | 9 KB      | ##################################### | 100% 
numpy-base-1.15.4    | 4.2 MB    | ##################################### | 100% 
Preparing transaction: done
Verifying transaction: done
Executing transaction: done

PHP compare two arrays and get the matched values not the difference

OK.. We needed to compare a dynamic number of product names...

There's probably a better way... but this works for me...

... because....Strings are just Arrays of characters.... :>}

//  Compare Strings ...  Return Matching Text and Differences with Product IDs...

//  From MySql...
$productID1 = 'abc123';
$productName1 = "EcoPlus Premio Jet 600";   

$productID2 = 'xyz789';
$productName2 = "EcoPlus Premio Jet 800";   

$ProductNames = array(
    $productID1 => $productName1,
    $productID2 => $productName2

function compareNames($ProductNames){   

    //  Convert NameStrings to Arrays...    
    foreach($ProductNames as $id => $product_name){
        $Package1[$id] = explode(" ",$product_name);    

    // Get Matching Text...
    $Matching = call_user_func_array('array_intersect', $Package1 );
    $MatchingText = implode(" ",$Matching);

    //  Get Different Text...
    foreach($Package1 as $id => $product_name_chunks){
        $Package2 = array($product_name_chunks,$Matching);
        $diff = call_user_func_array('array_diff', $Package2 );
        $DifferentText[$id] = trim(implode(" ", $diff));

    $results[$MatchingText]  = $DifferentText;              
    return $results;    

$Results =  compareNames($ProductNames);


// Gives us this...
[EcoPlus Premio Jet] 
        [abc123] => 600
        [xyz789] => 800

How to get file extension from string in C++

I've stumbled onto this question today myself, even though I already had a working code I figured out that it wouldn't work in some cases.

While some people already suggested using some external libraries, I prefer to write my own code for learning purposes.

Some answers included the method I was using in the first place (looking for the last "."), but I remembered that on linux hidden files/folders start with ".". So if file file is hidden and has no extension, the whole file name would be taken for extension. To avoid that I wrote this piece of code:

bool getFileExtension(const char * dir_separator, const std::string & file, std::string & ext)
    std::size_t ext_pos = file.rfind(".");
    std::size_t dir_pos = file.rfind(dir_separator);

        return true;

    return false;

I haven't tested this fully, but I think that it should work.

AngularJS $http-post - convert binary to excel file and download

I created a service that will do this for you.

Pass in a standard $http object, and add some extra parameters.

1) A "type" parameter. Specifying the type of file you're retrieving. Defaults to: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
2) A "fileName" parameter. This is required, and should include the extension.


  method : 'POST',
  url : '--- enter the url that returns a file here ---',
  data : ifYouHaveDataEnterItHere,
  type : 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', // this is the default
  fileName : 'YourFileName.xlsx'
}).then(res => {}).catch(e => {});

That's all you need. The file will be downloaded to the user's device without a popup.

Here's the git repo:

iterate through a map in javascript

The callback to $.each() is passed the property name and the value, in that order. You're therefore trying to iterate over the property names in the inner call to $.each(). I think you want:

$.each(myMap, function (i, val) {
  $.each(val, function(innerKey, innerValue) {
    // ...

In the inner loop, given an object like your map, the values are arrays. That's OK, but note that the "innerKey" values will all be numbers.

edit — Now once that's straightened out, here's the next problem:

    setTimeout(function () {

      // ...

    }, i * 6000);

The first time through that loop, "i" will be the string "partnr1". Thus, that multiplication attempt will result in a NaN. You can keep an external counter to keep track of the property count of the outer map:

var pcount = 1;
$.each(myMap, function(i, val) {
  $.each(val, function(innerKey, innerValue) {
    setTimeout(function() {
      // ...
    }, pcount++ * 6000);

Xcode - ld: library not found for -lPods

After hours of research this solution worked for me:

(disclaimer: results may vary due to circumstances)

the Library not found -lPods-(someCocoapod) error was due to multiple entries in the :

Settings(Target) > Build Settings > Linking > 'Other Linker Flags'

A lot of other posts had me look there and I would see changes to the error when I messed around with the entries, but I kept getting some variation on the same error.

Too many hours lost ...

My Fix:

remove the -lPods-(someCocoaPod) lines in the 'Other Linker Flags' list BUT only if $(inherited) is at the top. At first I was unsure, but the reassuring sign was that I still saw references to my cocoapods when I left the edit mode(inherited). I tested in debug and release, both of which were giving me errors, and the problem was immediately resolved.

What is a provisioning profile used for when developing iPhone applications?

A Quote from : iPhone Developer Program (~8MB PDF)

A provisioning profile is a collection of digital entities that uniquely ties developers and devices to an authorized iPhone Development Team and enables a device to be used for testing. A Development Provisioning Profile must be installed on each device on which you wish to run your application code. Each Development Provisioning Profile will contain a set of iPhone Development Certificates, Unique Device Identifiers and an App ID. Devices specified within the provisioning profile can be used for testing only by those individuals whose iPhone Development Certificates are included in the profile. A single device can contain multiple provisioning profiles.

Zoom to fit all markers in Mapbox or Leaflet

Leaflet also has LatLngBounds that even has an extend function, just like google maps.

So you could simply use:

var latlngbounds = new L.latLngBounds();

The rest is exactly the same.

How do I find all the files that were created today in Unix/Linux?

You can use find and ls to accomplish with this:

find . -type f -exec ls -l {} \; |  egrep "Aug 26";

It will find all files in this directory, display useful informations (-l) and filter the lines with some date you want... It may be a little bit slow, but still useful in some cases.

How to call a method after bean initialization is complete?

To further clear any confusion about the two approach i.e use of

  1. @PostConstruct and
  2. init-method="init"

From personal experience, I realized that using (1) only works in a servlet container, while (2) works in any environment, even in desktop applications. So, if you would be using Spring in a standalone application, you would have to use (2) to carry out that "call this method after initialization.

How to check if a URL exists or returns 404 with Java?

You may want to add

// note : or
//        huc.setInstanceFollowRedirects(false)

if you don't want to follow redirection (3XX)

Instead of doing a "GET", a "HEAD" is all you need.

return (huc.getResponseCode() == HttpURLConnection.HTTP_OK);

is there a function in lodash to replace matched item

[ES6] This code works for me.

let result = => === ? updatedItem : item)

Twitter-Bootstrap-2 logo image on top of navbar

You should remove navbar-fixed-top class otherwise navbar stays fixed on top of page where you want logo.

If you want to place logo inside navbar:

Navbar height (set in @navbarHeight LESS variable) is 40px by default. Your logo has to fit inside or you have to make navbar higher first.

Then use brand class:

<div class="navbar navbar-fixed-top">
  <div class="navbar-inner">
    <div class="container">
      <a href="/" class="brand"><img alt="" src="/logo.gif" /></a>

If your logo is higher than 20px, you have to fix stylesheets as well.

If you do that in LESS:

.navbar .brand {
  @elementHeight: 32px;
  padding: ((@navbarHeight - @elementHeight) / 2 - 2) 20px ((@navbarHeight - @elementHeight) / 2 + 2);

@elementHeight should be set to your image height.

Padding calculation is taken from Twitter Bootstrap LESS -

Alternatively you can calculate padding values yourself and use pure CSS.

This works for Twitter Bootstrap versions 2.0.x, should work in 2.1 as well, but padding calculation was changed a bit:

The view didn't return an HttpResponse object. It returned None instead

I had the same error using an UpdateView

I had this:

if form.is_valid() and form2.is_valid():
    return HttpResponseRedirect(self.get_success_url())

and I solved just doing:

if form.is_valid() and form2.is_valid():
    return HttpResponseRedirect(reverse_lazy('adopcion:solicitud_listar'))

How to hide action bar before activity is created, and then show it again?

Android studio provide in build template for full screen, if you use Android studio you can follow below step to implement full screen activity.

First Step to Create new Activity

Select select Full screen Activity

Done. Android studio did your job, now you can check code for full screen.

SQL Server IN vs. EXISTS Performance

The execution plans are typically going to be identical in these cases, but until you see how the optimizer factors in all the other aspects of indexes etc., you really will never know.

Why is it string.join(list) instead of list.join(string)?

I agree that it's counterintuitive at first, but there's a good reason. Join can't be a method of a list because:

  • it must work for different iterables too (tuples, generators, etc.)
  • it must have different behavior between different types of strings.

There are actually two join methods (Python 3.0):

>>> b"".join
<built-in method join of bytes object at 0x00A46800>
>>> "".join
<built-in method join of str object at 0x00A28D40>

If join was a method of a list, then it would have to inspect its arguments to decide which one of them to call. And you can't join byte and str together, so the way they have it now makes sense.

SASS :not selector

I tried re-creating this, and .someclass.notip was being generated for me but .someclass:not(.notip) was not, for as long as I did not have the @mixin tip() defined. Once I had that, it all worked.

$dropdown-width: 100px;
$comp-tip: true;

@mixin tip($pos:right) {


@mixin dropdown-pos($pos:right) {
  &:not(.notip) {
    @if $comp-tip == true{
      @if $pos == right {
        top:$dropdown-width * -0.6;
        background-color: #f00;
        @include tip($pos:$pos);
  &.notip {
    @if $pos == right {
      top: 0;
      left:$dropdown-width * 0.8;
      background-color: #00f;

.someclass { @include dropdown-pos(); }

EDIT: is a good place to debug your SASS because it gives you error messages. Undefined mixin 'tip'. it what I get when I remove @mixin tip($pos:right) { }

Correct way to work with vector of arrays

There is no error in the following piece of code:

float arr[4];
arr[0] = 6.28;
arr[1] = 2.50;
arr[2] = 9.73;
arr[3] = 4.364;
std::vector<float*> vec = std::vector<float*>();
float* ptr = vec.front();
for (int i = 0; i < 3; i++)
    printf("%g\n", ptr[i]);








is another possibility apart from

std::vector<std::array<double, 4>>

that James McNellis suggested.

Slide a layout up from bottom of screen

You just need to add some line in your app, please find it from below link:

Show and hide a View with a slide up/down animation

Just add an animation to your layout like this:


When do we need curly braces around shell variables?

You use {} for grouping. The braces are required to dereference array elements. Example:

dir=(*)           # store the contents of the directory into an array
echo "${dir[0]}"  # get the first entry.
echo "$dir[0]"    # incorrect

How do I put variable values into a text string in MATLAB?

As Peter and Amro illustrate, you have to convert numeric values to formatted strings first in order to display them or concatenate them with other character strings. You can do this using the functions FPRINTF, SPRINTF, NUM2STR, and INT2STR.

With respect to getting ans = 3 as an output, it is probably because you are not assigning the output from answer to a variable. If you want to get all of the output values, you will have to call answer in the following way:

[out1,out2,out3] = answer(1,2);

This will place the value d in out1, the value e in out2, and the value f in out3. When you do the following:


MATLAB will automatically assign the first output d (which has the value 3 in this case) to the default workspace variable ans.

With respect to suggesting a good resource for learning MATLAB, you shouldn't underestimate the value of the MATLAB documentation. I've learned most of what I know on my own using it. You can access it online, or within your copy of MATLAB using the functions DOC, HELP, or HELPWIN.

How can I set the PATH variable for javac so I can manually compile my .java works?

You don't need to do any complex command-line stuff or edit any system code. You simply have to open Computer, showing all of your disks and open properties. From there, go to Advanced System Settings and click Environment Variables. Scroll down in the lower list box and edit Path. Do not erase anything already there. Put a ; after it and then type in your path. To test, open command prompt and do "javac", it should list around 20 programs. You would be finished at that point.

By the way, the command to compile is javac -g not just javac.

Happy coding!

How to set app icon for Electron / Atom Shell App

If you want to update the app icon in the taskbar, then Update following in main.js (if using typescript then main.ts)

win.setIcon(path.join(__dirname, '/src/assets/logo-small.png'));

__dirname points to the root directory (same directory as package.json) of your application.

Draw a line in a div

Its working for me

width: 112px;_x000D_
height: 47px;_x000D_
border-bottom: 1px solid black;_x000D_
position: absolute;_x000D_
<div class="line"></div>

Single Form Hide on Startup

Here is a simple approach:
It's in C# (I don't have VB compiler at the moment)

public Form1()
    Hide(); // Also Visible = false can be used

private void Form1_Load(object sender, EventArgs e)
    Show(); // Or visible = true;

Explanation of BASE terminology

To add to the other answers, I think the acronyms were derived to show a scale between the two terms to distinguish how reliable transactions or requests where between RDMS versus Big Data.

From this article acid vs base

In Chemistry, pH measures the relative basicity and acidity of an aqueous (solvent in water) solution. The pH scale extends from 0 (highly acidic substances such as battery acid) to 14 (highly alkaline substances like lie); pure water at 77° F (25° C) has a pH of 7 and is neutral.

Data engineers have cleverly borrowed acid vs base from chemists and created acronyms that while not exact in their meanings, are still apt representations of what is happening within a given database system when discussing the reliability of transaction processing.

One other point, since I work with Big Data using Elasticsearch. To clarify, an instance of Elasticsearch is a node and a group of nodes form a cluster.

To me from a practical standpoint, BA (Basically Available), in this context, has the idea of multiple master nodes to handle the Elasticsearch cluster and it's operations.

If you have 3 master nodes and the currently directing master node goes down, the system stays up, albeit in a less efficient state, and another master node takes its place as the main directing master node. If two master nodes go down, the system still stays up and the last master node takes over.

Persist javascript variables across pages?

Yes, using Cookies. But be careful, don't put too much in them (I think there is a limit at 4kb). But a few variables are ok.

If you need to store considerably more than that, check out @Annie's great tips in the other answer. For small time data storage, I would say Cookies are the easiest thing.

Note that cookies are stored client side.

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

Use expandRows() from the splitstackshape package:

expandRows(df, "freq")

Simple syntax, very fast, works on data.frame or data.table.


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

DynamoDB vs MongoDB NoSQL

Short answer: Start with SQL and add NoSQL only when/if needed. (unless you don't need anything beyond very simple queries)

My personal experience: I haven't used MongoDB for queries but as of April 2015 DynamoDB is still very crippled when it comes to anything beyond the most basic key/value queries. I love it for the basic stuff but if you want query language then look to a real SQL database solution.

In DynamoDB you can query on a hash or on a hash and range key, and you can have multiple secondary global indexes. I'm doing queries on a single table with 4 possible filter parameters and sorting the results, this is supported (barely) through the use of the global secondary indexes with filter expressions. The problem comes in when you try to get the total results matching the filter, you can't just search for the first 10 items matching the filter, but rather it checks 10 items and you may get 0 valid results forcing you to keep re-scanning from the continue key - pain in the neck and consumes too much of your table read quota for a simple scenario.

To be specific about the limit problem with filters in the query, this is from the docs (

In a response, DynamoDB returns all the matching results within
the scope of the Limit value. For example, if you issue a Query 
or a Scan request with a Limit value of 6 and without a filter
expression, the operation returns the first six items in the 
table that match the request parameters. If you also supply a
FilterExpression, the operation returns the items within the 
first six items in the table that match the filter requirements.

My conclusion is that queries involving FilterExpressions are only usable on very rare occasions and are not scalable because each query can easily read most or all of your of your table which consumes far too many DynamoDB read units. Once you use too many read units you'll get throttled and see poor performance.

Expert opinion: In the AWS summit on Apr 9, 2015 Brett Hollman, Manager, Solutions Architecture, AWS in his talk on scalling to your first 10 million users advocates starting with a SQL database and then using NoSQL only when and if it makes sense. Because sooner or later you'll probably need a SQL server somewhere in your stack. His slides are here: See slide 28.

Name attribute in @Entity and @Table

@Entity(name = "someThing") => this name will be used to name the Entity
@Table(name = "someThing")  => this name will be used to name a table in DB

So, in the first case your table and entity will have the same name, that will allow you to access your table with the same name as the entity while writing HQL or JPQL.

And in second case while writing queries you have to use the name given in @Entity and the name given in @Table will be used to name the table in the DB.

So in HQL your someThing will refer to otherThing in the DB.

How to make type="number" to positive numbers only

<input type="number" min="1" step="1">

Select count(*) from result query

select count(*) from(select count(SID) from Test where Date = '2012-12-10' group by SID)select count(*) from(select count(SID) from Test where Date = '2012-12-10' group by SID)

should works

SQL Server : check if variable is Empty or NULL for WHERE clause

WHERE p.[Type] = isnull(@SearchType, p.[Type])

iOS detect if user is on an iPad


In swift 3.0


 if UIDevice.current.userInterfaceIdiom == .pad {
    } else if UIDevice.current.userInterfaceIdiom == .phone {
    } else if UIDevice.current.userInterfaceIdiom == .tv {
    } else if UIDevice.current.userInterfaceIdiom == .carPlay {
    } else {

Why do people use Heroku when AWS is present? What distinguishes Heroku from AWS?

AWS / Heroku are both free for small hobby projects (to start with).

If you want to start an app right away, without much customization of the architecture, then choose Heroku.

If you want to focus on the architecture and to be able to use different web servers, then choose AWS. AWS is more time-consuming based on what service/product you choose, but can be worth it. AWS also comes with many plugin services and products.


  • Platform as a Service (PAAS)
  • Good documentation
  • Has built-in tools and architecture.
  • Limited control over architecture while designing the app.
  • Deployment is taken care of (automatic via GitHub or manual via git commands or CLI).
  • Not time consuming.


  • Infrastructure as a Service (IAAS)
  • Versatile - has many products such as EC2, LAMBDA, EMR, etc.
  • Can use a Dedicated instance for more control over the architecture, such as choosing the OS, software version, etc. There is more than one backend layer.
  • Elastic Beanstalk is a feature similar to Heroku's PAAS.
  • Can use the automated deployment, or roll your own.

How to fix "Referenced assembly does not have a strong name" error?

Situation: You had project A,B,C,D in solution X,Y

Project A, B, C in X Project A, C, D in Y

I need use project C in project A, but later i dont use. In bin Debug project A had C.dll.

If I compile solution X, all good ( in this solution i delete reference A -> C. ), but in solution Y I get this problem.

Solution is delete C.dll in project A bin Debug

Sort array of objects by single key with date value

var months = [
        "updated_at" : "2012-01-01T06:25:24Z",
        "foo" : "bar"
        "updated_at" : "2012-01-09T11:25:13Z",
        "foo" : "bar"
        "updated_at" : "2012-01-05T04:13:24Z",
        "foo" : "bar"
months.sort((a, b)=>{
    var keyA = new Date(a.updated_at),
        keyB = new Date(b.updated_at);
    // Compare the 2 dates
    if(keyA < keyB) return -1;
    if(keyA > keyB) return 1;
    return 0;

Understanding timedelta

Because timedelta is defined like:

class datetime.timedelta([days,] [seconds,] [microseconds,] [milliseconds,] [minutes,] [hours,] [weeks])

All arguments are optional and default to 0.

You can easily say "Three days and four milliseconds" with optional arguments that way.

>>> datetime.timedelta(days=3, milliseconds=4)
datetime.timedelta(3, 0, 4000)
>>> datetime.timedelta(3, 0, 0, 4) #no need for that.
datetime.timedelta(3, 0, 4000)

And for str casting, it returns a nice formatted value instead of __repr__ to improve readability. From docs:

str(t) Returns a string in the form [D day[s], ][H]H:MM:SS[.UUUUUU], where D is negative for negative t. (5)

>>> datetime.timedelta(seconds = 42).__repr__()
'datetime.timedelta(0, 42)'
>>> datetime.timedelta(seconds = 42).__str__()

Checkout documentation:

How to create a Java cron job

You can use TimerTask for Cronjobs.

public class Main{
   public static void main(String[] args){

     Timer t = new Timer();
     MyTask mTask = new MyTask();
     // This task is scheduled to run every 10 seconds

     t.scheduleAtFixedRate(mTask, 0, 10000);


class MyTask extends TimerTask{

   public MyTask(){
     //Some stuffs

   public void run() {
     System.out.println("Hi see you after 10 seconds");


Alternative You can also use ScheduledExecutorService.

Java 'file.delete()' Is not Deleting Specified File

In my case I was processing a set of jar files contained in a directory. After I processed them I tried to delete them from that directory, but they wouldn't delete. I was using JarFile to process them and the problem was that I forgot to close the JarFile when I was done.

How do I get the current mouse screen coordinates in WPF?

If you try a lot of these answers out on different resolutions, computers with multiple monitors, etc. you may find that they don't work reliably. This is because you need to use a transform to get the mouse position relative to the current screen, not the entire viewing area which consists of all your monitors. Something like this...(where "this" is a WPF window).

var transform = PresentationSource.FromVisual(this).CompositionTarget.TransformFromDevice;
var mouse = transform.Transform(GetMousePosition());

public System.Windows.Point GetMousePosition()
    var point = Forms.Control.MousePosition;
    return new Point(point.X, point.Y);

Best practices for SQL varchar column length

Always check with your business domain expert. If that's you, look for an industry standard. If, for example, the domain in question is a natural person's family name (surname) then for a UK business I'd go to the UK Govtalk data standards catalogue for person information and discover that a family name will be between 1 and 35 characters.

Time in milliseconds in C

Modern processors are too fast to register the running time. Hence it may return zero. In this case, the time you started and ended is too small and therefore both the times are the same after round of.

Using iFrames In ASP.NET

try this

<iframe name="myIframe" id="myIframe" width="400px" height="400px" runat="server"></iframe>

Expose this iframe in the master page's codebehind:

public HtmlControl iframe
return this.myIframe;

Add the MasterType directive for the content page to strongly typed Master Page.

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits=_Default" Title="Untitled Page" %>
<%@ MasterType VirtualPath="~/MasterPage.master" %>

In code behind

protected void Page_Load(object sender, EventArgs e)
this.Master.iframe.Attributes.Add("src", "some.aspx");

Display HTML form values in same page after submit using Ajax

display html form values in same page after clicking on submit button using JS & html codes. After opening it up again it should give that comments in that page.

CMake unable to determine linker language with C++

In my case, it was just because there were no source file in the target. All of my library was template with source code in the header. Adding an empty file.cpp solved the problem.

Which characters need to be escaped in HTML?

It depends upon the context. Some possible contexts in HTML:

  • document body
  • inside common attributes
  • inside script tags
  • inside style tags
  • several more!

See OWASP's Cross Site Scripting Prevention Cheat Sheet, especially the "Why Can't I Just HTML Entity Encode Untrusted Data?" and "XSS Prevention Rules" sections. However, it's best to read the whole document.

Selenium Finding elements by class name in python

You can try to get the list of all elements with class = "content" by using find_elements_by_class_name:

a = driver.find_elements_by_class_name("content")

Then you can click on the link that you are looking for.

Number of days between two dates in Joda-Time

Days Class

Using the Days class with the withTimeAtStartOfDay method should work:

Days.daysBetween(start.withTimeAtStartOfDay() , end.withTimeAtStartOfDay() ).getDays() 

How to align checkboxes and their labels consistently cross-browsers

This works well for me:

fieldset {_x000D_
fieldset ol, fieldset ul {_x000D_
fieldset li {_x000D_
label {_x000D_
fieldset.checkboxes li {_x000D_
fieldset.checkboxes label {_x000D_
  margin:0 0 0 1em;_x000D_
fieldset.checkboxes input {_x000D_
  <fieldset class="checkboxes">_x000D_
        <input type="checkbox" name="happy" value="yep" id="happy" />_x000D_
        <label for="happy">Happy?</label>_x000D_
        <input type="checkbox" name="hungry" value="yep" id="hungry" />_x000D_
        <label for="hungry">Hungry?</label>_x000D_

How can I compare two lists in python and return matches

you can | for set union and & for set intersection.
for example:



curly braces in the answer.

For Restful API, can GET method use json data?

In theory, there's nothing preventing you from sending a request body in a GET request. The HTTP protocol allows it, but have no defined semantics, so it's up to you to document what exactly is going to happen when a client sends a GET payload. For instance, you have to define if parameters in a JSON body are equivalent to querystring parameters or something else entirely.

However, since there are no clearly defined semantics, you have no guarantee that implementations between your application and the client will respect it. A server or proxy might reject the whole request, or ignore the body, or anything else. The REST way to deal with broken implementations is to circumvent it in a way that's decoupled from your application, so I'd say you have two options that can be considered best practices.

The simple option is to use POST instead of GET as recommended by other answers. Since POST is not standardized by HTTP, you'll have to document how exactly that's supposed to work.

Another option, which I prefer, is to implement your application assuming the GET payload is never tampered with. Then, in case something has a broken implementation, you allow clients to override the HTTP method with the X-HTTP-Method-Override, which is a popular convention for clients to emulate HTTP methods with POST. So, if a client has a broken implementation, it can write the GET request as a POST, sending the X-HTTP-Method-Override: GET method, and you can have a middleware that's decoupled from your application implementation and rewrites the method accordingly. This is the best option if you're a purist.

How to output only captured groups with sed?

Sed has up to nine remembered patterns but you need to use escaped parentheses to remember portions of the regular expression.

See here for examples and more detail

Android button with different background colors

As your error states, you have to define drawable attibute for the items (for some reason it is required when it comes to background definitions), so:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
    <item android:state_pressed="true" android:drawable="@color/red"/> <!-- pressed -->
    <item android:state_focused="true" android:drawable="@color/blue"/> <!-- focused -->
    <item android:drawable="@color/black"/> <!-- default -->

Also note that drawable attribute doesn't accept raw color values, so you have to define the colors as resources. Create colors.xml file at res/values folder:

<?xml version="1.0" encoding="utf-8"?>
     <color name="black">#000</color>
     <color name="blue">#00f</color>
     <color name="red">#f00</color>

How to get the string size in bytes?

I like to use:

(strlen(string) + 1 ) * sizeof(char)

This will give you the buffer size in bytes. You can use this with snprintf() may help:

const char* message = "%s, World!";
char* string = (char*)malloc((strlen(message)+1))*sizeof(char));
snprintf(string, (strlen(message)+1))*sizeof(char), message, "Hello");

Cheers! Function: size_t strlen (const char *s)

Why doesn't indexOf work on an array IE8?

Versions of IE before IE9 don't have an .indexOf() function for Array, to define the exact spec version, run this before trying to use it:

if (!Array.prototype.indexOf)
  Array.prototype.indexOf = function(elt /*, from*/)
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
      if (from in this &&
          this[from] === elt)
        return from;
    return -1;

This is the version from MDN, used in Firefox/SpiderMonkey. In other cases such as IE, it'll add .indexOf() in the case it's missing... basically IE8 or below at this point.

How to convert a DataTable to a string in C#?

I created my variant of class for your needs. I believe it is a bit more configurable than already provided variants. You can use it with all default settings just create an instance of a class and call StringifyDataTable method, or you can set additional options if needed.

public class DataTableStringifier
    public bool IsOuterBordersPresent { get; set; } //Whether outer borders of table needed
    public bool IsHeaderHorizontalSeparatorPresent { get; set; } // Whether horizontal line separator between table title and data is needed. Useful to set 'false' if you expect only 1 or 2 rows of data - no need for additional lines then
    public char ValueSeparator { get; set; } //Vertical line character
    public char HorizontalLinePadChar { get; set; } // Horizontal line character
    public char HorizontalLineSeparator { get; set; } // Horizontal border (between header and data) column separator (crossing of horizontal and vertical borders)
    public int ValueMargin { get; set; } // Horizontal margin from table borders (inner and outer) to cell values
    public int MaxColumnWidth { get; set; } // To avoid too wide columns with thousands of characters. Longer values will be cropped in the center
    public string LongValuesEllipses { get; set; } // Cropped values wil be inserted this string in the middle to mark the point of cropping

    public DataTableStringifier()
        MaxColumnWidth = int.MaxValue;
        IsHeaderHorizontalSeparatorPresent = true;
        ValueSeparator = '|';
        ValueMargin = 1;
        HorizontalLinePadChar = '-';
        HorizontalLineSeparator = '+';
        LongValuesEllipses = "...";
        IsOuterBordersPresent = false;

    public string StringifyDataTable(DataTable table)
        int colCount = table.Columns.Count;
        int rowCount = table.Rows.Count;
        string[] colHeaders = new string[colCount];
        string[,] cells = new string[rowCount, colCount];
        int[] colWidth = new int[colCount];

        for (int i = 0; i < colCount; i++)
            var column = table.Columns[i];
            var colName = ValueToLimitedLengthString(column.ColumnName);
            colHeaders[i] = colName;
            if (colWidth[i] < colName.Length)
                colWidth[i] = colName.Length;

        for (int i = 0; i < rowCount; i++)
            DataRow row = table.Rows[i];
            for (int j = 0; j < colCount; j++)
                var valStr = ValueToLimitedLengthString(row[j]);
                cells[i, j] = valStr;
                if (colWidth[j] < valStr.Length)
                    colWidth[j] = valStr.Length;

        string valueSeparatorWithMargin = string.Concat(new string(' ', ValueMargin), ValueSeparator, new string(' ', ValueMargin));
        string leftBorder = IsOuterBordersPresent ? string.Concat(ValueSeparator, new string(' ', ValueMargin)) : "";
        string rightBorder = IsOuterBordersPresent ? string.Concat(new string(' ', ValueMargin), ValueSeparator) : "";
        string horizLine = new string(HorizontalLinePadChar, colWidth.Sum() + (colCount - 1)*(ValueMargin*2 + 1) + (IsOuterBordersPresent ? (ValueMargin + 1)*2 : 0));

        StringBuilder tableBuilder = new StringBuilder();

        if (IsOuterBordersPresent)

        for (int i = 0; i < colCount; i++)
            if (i < colCount - 1)

        if (IsHeaderHorizontalSeparatorPresent)
            if (IsOuterBordersPresent)
                tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
            for (int i = 0; i < colCount; i++)
                tableBuilder.Append(new string(HorizontalLinePadChar, colWidth[i]));
                if (i < colCount - 1)
                    tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
                    tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
            if (IsOuterBordersPresent)
                tableBuilder.Append(HorizontalLinePadChar, ValueMargin);

        for (int i = 0; i < rowCount; i++)
            for(int j=0; j<colCount; j++)
                tableBuilder.Append(cells[i, j].PadRight(colWidth[j]));

        if (IsOuterBordersPresent)

        return tableBuilder.ToString(0, tableBuilder.Length - 1); //Trim last enter char

    private string ValueToLimitedLengthString(object value)
        string strValue = value.ToString();
        if (strValue.Length > MaxColumnWidth)
            int beginningLength = (MaxColumnWidth) / 2;
            int endingLength = (MaxColumnWidth + 1) / 2 - LongValuesEllipses.Length;
            return string.Concat(strValue.Substring(0, beginningLength), LongValuesEllipses, strValue.Substring(strValue.Length - endingLength, endingLength));
            return strValue;

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

I am late for this but i want put some more solution relevant to this.

public ResponseEntity<List<JSONObject>> getRole() {
    return ResponseEntity.ok(service.getRole());

How can I show dots ("...") in a span with hidden overflow?

For this you can use text-overflow: ellipsis; property. Write like this

span {_x000D_
    display: inline-block;_x000D_
    width: 180px;_x000D_
    white-space: nowrap;_x000D_
    overflow: hidden !important;_x000D_
    text-overflow: ellipsis;_x000D_
<span>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book</span>


How do I use itertools.groupby()?

This basic implementation helped me understand this function. Hope it helps others as well:

arr = [(1, "A"), (1, "B"), (1, "C"), (2, "D"), (2, "E"), (3, "F")]

for k,g in groupby(arr, lambda x: x[0]):
    print("--", k, "--")
    for tup in g:
        print(tup[1])  # tup[0] == k
-- 1 --
-- 2 --
-- 3 --

Installing Node.js (and npm) on Windows 10

You should run the installer as administrator.

  1. Run the command prompt as administrator
  2. cd directory where msi file is present
  3. launch msi file by typing the name in the command prompt
  4. You should be happy to see all node commands work from new command prompt shell

How can I color dots in a xy scatterplot according to column value?

Recently I had to do something similar and I resolved it with the code below. Hope it helps!

Sub ColorCode()
Dim i As Integer
Dim j As Integer
i = 2
j = 1

Do While ActiveSheet.Cells(i, 1) <> ""

If Cells(i, 5).Value = "RED" Then
ActiveSheet.ChartObjects("YourChartName").Chart.FullSeriesCollection(1).Points(j).MarkerForegroundColor = RGB(255, 0, 0)


If Cells(i, 5).Value = "GREEN" Then
ActiveSheet.ChartObjects("YourChartName").Chart.FullSeriesCollection(1).Points(j).MarkerForegroundColor = RGB(0, 255, 0)


If Cells(i, 5).Value = "GREY" Then
ActiveSheet.ChartObjects("YourChartName").Chart.FullSeriesCollection(1).Points(j).MarkerForegroundColor = RGB(192, 192, 192)


If Cells(i, 5).Value = "YELLOW" Then
ActiveSheet.ChartObjects("YourChartName").Chart.FullSeriesCollection(1).Points(j).MarkerForegroundColor = RGB(255, 255, 0)

End If
End If
End If
End If

i = i + 1
j = j + 1


End Sub

WRONGTYPE Operation against a key holding the wrong kind of value php

This error means that the value indexed by the key "l_messages" is not of type hash, but rather something else. You've probably set it to that other value earlier in your code. Try various other value-getter commands, starting with GET, to see which one works and you'll know what type is actually here.

How to check if a file is empty in Bash?

@geedoubleya answer is my favorite.

However, I do prefer this

if [[ -f diff.txt && -s diff.txt ]]
  rm -f empty.txt
  touch full.txt
elif [[ -f diff.txt && ! -s diff.txt ]]
  rm -f full.txt
  touch empty.txt
  echo "File diff.txt does not exist"

How to change color in circular progress bar?

For API 21 and Higher. Simply set the indeterminateTint property. Like:


To support pre-API 21 devices:

                .setColorFilter(ContextCompat.getColor(this, R.color.colorPrimary), PorterDuff.Mode.SRC_IN );

ValueError: max() arg is an empty sequence

I realized that I was iterating over a list of lists where some of them were empty. I fixed this by adding this preprocessing step:

tfidfLsNew = [x for x in tfidfLs if x != []]

the len() of the original was 3105, and the len() of the latter was 3101, implying that four of my lists were completely empty. After this preprocess my max() min() etc. were functioning again.

How to convert an object to JSON correctly in Angular 2 with TypeScript

In your product.service.ts you are using stringify method in a wrong way..

Just use


instead of


i have checked your problem and after this it's working absolutely fine.

Using Mockito, how do I verify a method was a called with a certain argument?

Building off of Mamboking's answer:

ContractsDao mock_contractsDao = mock(ContractsDao.class);
when("Some result");

m_orderSvc.m_contractsDao = mock_contractsDao;
m_prog = new ProcessOrdersWorker(m_orderSvc, m_opportunitySvc, m_myprojectOrgSvc);; 

Addressing your request to verify whether the argument contains a certain value, I could assume you mean that the argument is a String and you want to test whether the String argument contains a substring. For this you could do:

ArgumentCaptor<String> savedCaptor = ArgumentCaptor.forClass(String.class);
assertTrue(savedCaptor.getValue().contains("substring I want to find");

If that assumption was wrong, and the argument to save() is a collection of some kind, it would be only slightly different:

ArgumentCaptor<Collection<MyType>> savedCaptor = ArgumentCaptor.forClass(Collection.class);

You might also check into ArgumentMatchers, if you know how to use Hamcrest matchers.

Unable to load script from assets on windows

For this problem I just solve it by running:

react-native start


adb reverse tcp:8081 tcp:8081

on command line. And then i can run:

react-native run-android

So i will not waste my time to run:

react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/ --assets-dest android/app/src/main/res

every time.

How should strace be used?

Strace is a tool that tells you how your application interacts with your operating system.

It does this by telling you what OS system calls your application uses and with what parameters it calls them.

So for instance you see what files your program tries to open, and weather the call succeeds.

You can debug all sorts of problems with this tool. For instance if application says that it cannot find library that you know you have installed you strace would tell you where the application is looking for that file.

And that is just a tip of the iceberg.

View RDD contents in Python Spark?

Try this:

data = f.flatMap(lambda x: x.split(' '))
map = x: (x, 1))
mapreduce = map.reduceByKey(lambda x,y: x+y)
result = mapreduce.collect()

Please note that when you run collect(), the RDD - which is a distributed data set is aggregated at the driver node and is essentially converted to a list. So obviously, it won't be a good idea to collect() a 2T data set. If all you need is a couple of samples from your RDD, use take(10).

URL Encode a string in jQuery for an AJAX request

try this one

var query = "{% url accounts.views.instasearch  %}?q=" + $('#tags').val().replace(/ /g, '+');

R solve:system is exactly singular

I guess your code uses somewhere in the second case a singular matrix (i.e. not invertible), and the solve function needs to invert it. This has nothing to do with the size but with the fact that some of your vectors are (probably) colinear.

What characters are valid for JavaScript variable names?

Javascript Variables

You can start a variable with any letter, $, or _ character. As long as it doesn't start with a number, you can include numbers as well.

Start: [a-z], $, _

Contain: [a-z], [0-9], $, _


You can use _ for your library so that it will stand side-by-side with jQuery. However, there is a configuration you can set so that jQuery will not use $. It will instead use jQuery. To do this, simply set:


This page explains how to do this.

Selecting a Linux I/O Scheduler

The aim of having the kernel support different ones is that you can try them out without a reboot; you can then run test workloads through the sytsem, measure performance, and then make that the standard one for your app.

On modern server-grade hardware, only the noop one appears to be at all useful. The others seem slower in my tests.

Get path to execution directory of Windows Forms application

Both of the examples are in VB.NET.

Debug path:

TextBox1.Text = My.Application.Info.DirectoryPath

EXE path:

TextBox2.Text = IO.Path.GetFullPath(Application.ExecutablePath)

Oracle's default date format is YYYY-MM-DD, WHY?

Oracle has both the Date and the Timestamp data types.

According to Oracle documentation, there are differences in data size between Date and Timestamp, so when the intention is to have a Date only field it makes sense to show the Date formatting. Also, "It does not have fractional seconds or a time zone." - so it is not the best choice when timestamp information is required.

The Date field can be easily formatted to show the time component in the Oracle SQL Developer - Date query ran in PL/SQL Developer shows time, but does not show in Oracle SQL Developer. But it won't show the fractional seconds or the time zone - for this you need Timestamp data type.

Understanding slice notation

Found this great table at

Python indexes and slices for a six-element list.
Indexes enumerate the elements, slices enumerate the spaces between the elements.

Index from rear:    -6  -5  -4  -3  -2  -1      a=[0,1,2,3,4,5]    a[1:]==[1,2,3,4,5]
Index from front:    0   1   2   3   4   5      len(a)==6          a[:5]==[0,1,2,3,4]
                   +---+---+---+---+---+---+    a[0]==0            a[:-2]==[0,1,2,3]
                   | a | b | c | d | e | f |    a[5]==5            a[1:2]==[1]
                   +---+---+---+---+---+---+    a[-1]==5           a[1:-1]==[1,2,3,4]
Slice from front:  :   1   2   3   4   5   :    a[-2]==4
Slice from rear:   :  -5  -4  -3  -2  -1   :
                                                b==[0,1,2,3,4,5] (shallow copy of a)

How to Scroll Down - JQuery

This can be used in to solve this problem

<div id='scrol'></div> 

in javascript use this


Ruby on Rails generates model field:type - what are the options for field:type?

Remember to not capitalize your text when writing this command. For example:

Do write:

rails g model product title:string description:text image_url:string price:decimal

Do not write:

rails g Model product title:string description:text image_url:string price:decimal

At least it was a problem to me.

HTML table sort

Check if you could go with any of the below mentioned JQuery plugins. Simply awesome and provide wide range of options to work through, and less pains to integrate. :) - Flexgrid - Data tables.

If not, you need to have a link to those table headers that calls a server-side script to invoke the sort.

Determine the number of NA values in a column

If you are looking to count the number of NAs in the entire dataframe you could also use


Execute combine multiple Linux commands in one line

If you want to execute each command only if the previous one succeeded, then combine them using the && operator:

cd /my_folder && rm *.jar && svn co path to repo && mvn compile package install

If one of the commands fails, then all other commands following it won't be executed.

If you want to execute all commands regardless of whether the previous ones failed or not, separate them with semicolons:

cd /my_folder; rm *.jar; svn co path to repo; mvn compile package install

In your case, I think you want the first case where execution of the next command depends on the success of the previous one.

You can also put all commands in a script and execute that instead:

#! /bin/sh
cd /my_folder \
&& rm *.jar \
&& svn co path to repo \
&& mvn compile package install

(The backslashes at the end of the line are there to prevent the shell from thinking that the next line is a new command; if you omit the backslashes, you would need to write the whole command in a single line.)

Save that to a file, for example myscript, and make it executable:

chmod +x myscript

You can now execute that script like other programs on the machine. But if you don't place it inside a directory listed in your PATH environment variable (for example /usr/local/bin, or on some Linux distributions ~/bin), then you will need to specify the path to that script. If it's in the current directory, you execute it with:


The commands in the script work the same way as the commands in the first example; the next command only executes if the previous one succeeded. For unconditional execution of all commands, simply list each command on its own line:

#! /bin/sh
cd /my_folder
rm *.jar
svn co path to repo
mvn compile package install

Creating C formatted strings (not printing them)

If you have the code to log_out(), rewrite it. Most likely, you can do:

static FILE *logfp = ...;

void log_out(const char *fmt, ...)
    va_list args;

    va_start(args, fmt);
    vfprintf(logfp, fmt, args);

If there is extra logging information needed, that can be printed before or after the message shown. This saves memory allocation and dubious buffer sizes and so on and so forth. You probably need to initialize logfp to zero (null pointer) and check whether it is null and open the log file as appropriate - but the code in the existing log_out() should be dealing with that anyway.

The advantage to this solution is that you can simply call it as if it was a variant of printf(); indeed, it is a minor variant on printf().

If you don't have the code to log_out(), consider whether you can replace it with a variant such as the one outlined above. Whether you can use the same name will depend on your application framework and the ultimate source of the current log_out() function. If it is in the same object file as another indispensable function, you would have to use a new name. If you cannot work out how to replicate it exactly, you will have to use some variant like those given in other answers that allocates an appropriate amount of memory.

void log_out_wrapper(const char *fmt, ...)
    va_list args;
    size_t  len;
    char   *space;

    va_start(args, fmt);
    len = vsnprintf(0, 0, fmt, args);
    if ((space = malloc(len + 1)) != 0)
         va_start(args, fmt);
         vsnprintf(space, len+1, fmt, args);
    /* else - what to do if memory allocation fails? */

Obviously, you now call the log_out_wrapper() instead of log_out() - but the memory allocation and so on is done once. I reserve the right to be over-allocating space by one unnecessary byte - I've not double-checked whether the length returned by vsnprintf() includes the terminating null or not.

Fatal error: Call to undefined function mysqli_connect()

I followed below link to fix this problem. Make sure to enable following Module.
php -r 'phpinfo();' | grep -i mysqli
Link :

'Static readonly' vs. 'const'


  1. value should be given upon declaration
  2. compile time constant


  1. value can be given upon declaration or during runtime using constructors.The value may vary depend upon the constructor used.
  2. run time constant

Select value if condition in SQL Server

Try Case

         WHEN stock.quantity <20 THEN 'Buy urgent'
         ELSE 'There is enough'
FROM stock

mysql stored-procedure: out parameter

If you are calling from within Stored Procedure don't use @. In my case it returns 0


How to check if object has any properties in JavaScript?

With jQuery you can use:

$.isEmptyObject(obj); // Returns: Boolean

As of jQuery 1.4 this method checks both properties on the object itself and properties inherited from prototypes (in that it doesn't use hasOwnProperty).

With ECMAScript 5th Edition in modern browsers (IE9+, FF4+, Chrome5+, Opera12+, Safari5+) you can use the built in Object.keys method:

var obj = { blah: 1 };
var isEmpty = !Object.keys(obj).length;

Or plain old JavaScript:

var isEmpty = function(obj) {
               for(var p in obj){
                  return false;
               return true;

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


"Internally, the elements in a map are always sorted by its key following a specific strict weak ordering criterion indicated by its internal comparison object (of type Compare).

map containers are generally slower than unordered_map containers to access individual elements by their key, but they allow the direct iteration on subsets based on their order."

Custom alert and confirm box in jquery

I made custom messagebox using jquery UI component. Here is demo

You have to pass just the parameters like caption name, message, button's text. You can specify trigger function on any button click. This will helpful for you.

Passing a variable from one php include file to another: global vs. not

When including files in PHP, it acts like the code exists within the file they are being included from. Imagine copy and pasting the code from within each of your included files directly into your index.php. That is how PHP works with includes.

So, in your example, since you've set a variable called $name in your file, and then included both and in your index.php, you will be able to echo the variable $name anywhere after the include of within your index.php. Again, PHP processes your index.php as if the code from the two files you are including are part of the file.

When you place an echo within an included file, to a variable that is not defined within itself, you're not going to get a result because it is treated separately then any other included file.

In other words, to do the behavior you're expecting, you will need to define it as a global.

add new element in laravel collection object

If you want to add item to the beginning of the collection you can use prepend:

$item->prepend($product, 'key');

How do I change TextView Value inside Java Code?

I presume that this question is a continuation of this one.

What are you trying to do? Do you really want to dynamically change the text in your TextView objects when the user clicks a button? You can certainly do that, if you have a reason, but, if the text is static, it is usually set in the main.xml file, like this:


The string "@string/rate" refers to an entry in your strings.xml file that looks like this:

<string name="rate">Rate</string>

If you really want to change this text later, you can do so by using Nikolay's example - you'd get a reference to the TextView by utilizing the id defined for it within main.xml, like this:

final TextView textViewToChange = (TextView) findViewById(;
    "The new text that I'd like to display now that the user has pushed a button.");

Assigning a variable NaN in python without numpy

You can do float('nan') to get NaN.

Winforms issue - Error creating window handle

Well, in my case it was definitely the USER Objects that were out of control. I looked in the Windows Task Manager and sure enough, the USER Objects count was at 10'000 exactly.

I am dynamically embedding property and list sheets in Tab Pages by setting the Parent property of the property or list sheet's container panel to that of the Tab Page. I am conditionally recycling or re-creating the property and list sheet forms depending on the type of collection being listed or class type of the object being inspected.

NB: In Delphi, all controls had an Owner and a Parent property. Even if one changed the Parent property of a control, it would still be disposed by its owner when the owning control got destroyed.

In C# it seems that if a control e.g. a Panel is programmatically reassigned from, say, a Form to a Tab Page by changing the Panel.Parent property, calling Dispose() on the Form won't dispose the Panel, neither will calling Controls.Clear() on the Tab Page. Even a direct call Panel.Dispose() won't actually dispose it, unless its Parent is manually set to null beforehand.

set dropdown value by text using jquery

For GOOGLE, GOOGLEDOWN, GOOGLEUP i.e similar kind of value you can try below code

   $("#HowYouKnow option:contains('GOOGLE')").each(function () {

                            $(this).attr('selected', 'selected');

In this way,number of loop iteration can be reduced and will work in all situation.


You can get this error if the minSdkVersion in builde.gradle is bigger than the device's Android version. In that case you have to modify the minSdkVersion.

Rounding up to next power of 2

#define __LOG2A(s) ((s &0xffffffff00000000) ? (32 +__LOG2B(s >>32)): (__LOG2B(s)))
#define __LOG2B(s) ((s &0xffff0000)         ? (16 +__LOG2C(s >>16)): (__LOG2C(s)))
#define __LOG2C(s) ((s &0xff00)             ? (8  +__LOG2D(s >>8)) : (__LOG2D(s)))
#define __LOG2D(s) ((s &0xf0)               ? (4  +__LOG2E(s >>4)) : (__LOG2E(s)))
#define __LOG2E(s) ((s &0xc)                ? (2  +__LOG2F(s >>2)) : (__LOG2F(s)))
#define __LOG2F(s) ((s &0x2)                ? (1)                  : (0))

#define LOG2_UINT64 __LOG2A
#define LOG2_UINT32 __LOG2B
#define LOG2_UINT16 __LOG2C
#define LOG2_UINT8  __LOG2D

static inline uint64_t
next_power_of_2(uint64_t i)
#if defined(__GNUC__)
    return 1UL <<(1 +(63 -__builtin_clzl(i -1)));
    i =i -1;
    i =LOG2_UINT64(i);
    return 1UL <<(1 +i);

If you do not want to venture into the realm of undefined behaviour the input value must be between 1 and 2^63. The macro is also useful to set constant at compile time.

How can I concatenate a string and a number in Python?

You would have to convert the int into a string.

# This program calculates a workers gross pay

hours = float(raw_input("Enter hours worked: \n"))

rate = float(raw_input("Enter your hourly rate of pay: \n"))

gross = hours * rate

print "Your gross pay for working " +str(hours)+ " at a rate of " + str(rate) + " hourly is $"  + str(gross)

Sorting Python list based on the length of the string

The easiest way to do this is:

list.sort(key = lambda x:len(x))

MVC4 Passing model from view to controller

I hope this complete example will help you.

This is the TaxiInfo class which holds information about a taxi ride:

namespace Taxi.Models
    public class TaxiInfo
        public String Driver { get; set; }
        public Double Fare { get; set; }
        public Double Distance { get; set; }
        public String StartLocation { get; set; }
        public String EndLocation { get; set; }

We also have a convenience model which holds a List of TaxiInfo(s):

namespace Taxi.Models
    public class TaxiInfoSet
        public List<TaxiInfo> TaxiInfoList { get; set; }

        public TaxiInfoSet(params TaxiInfo[] TaxiInfos)
            TaxiInfoList = new List<TaxiInfo>();

            foreach(var TaxiInfo in TaxiInfos)

Now in the home controller we have the default Index action which for this example makes two taxi drivers and adds them to the list contained in a TaxiInfo:

public ActionResult Index()
    var taxi1 = new TaxiInfo() { Fare = 20.2, Distance = 15, Driver = "Billy", StartLocation = "Perth", EndLocation = "Brisbane" };
    var taxi2 = new TaxiInfo() { Fare = 2339.2, Distance = 1500, Driver = "Smith", StartLocation = "Perth", EndLocation = "America" };

    return View(new TaxiInfoSet(taxi1,taxi2));

The code for the view is as follows:

@model Taxi.Models.TaxiInfoSet
    ViewBag.Title = "Index";


@foreach(var TaxiInfo in Model.TaxiInfoList){
        <h1>Cost: [email protected]</h1>
        <h2>Distance: @(TaxiInfo.Distance) km</h2>
            Our diver, @TaxiInfo.Driver will take you from @TaxiInfo.StartLocation to @TaxiInfo.EndLocation

The ActionLink is responsible for the re-directing to the booking action of the Home controller (and passing in the appropriate TaxiInfo object) which is defiend as follows:

    public ActionResult Booking(TaxiInfo Taxi)
        return View(Taxi);

This returns a the following view:

@model Taxi.Models.TaxiInfo

    ViewBag.Title = "Booking";

<h2>Booking For</h2>
<h1>@Model.Driver, going from @Model.StartLocation to @Model.EndLocation (a total of @Model.Distance km) for [email protected]</h1>

A visual tour:

The Index view

The Booking view

Checking whether the pip is installed?

In CMD, type:

pip freeze

And it will show you a list of all the modules installed including the version number.



curl usage to get header is not responding to HTTP HEAD requests, which is why you are seeing a hang for the first command.

It does respond to GET requests, which is why the third command works.

As for the second, curl just prints the headers from a standard request.

Group By Eloquent ORM

try: ->unique('column')


$users = User::get()->unique('column');

How to check is Apache2 is stopped in Ubuntu?

In the command line type service apache2 status then hit enter. The result should say:

Apache2 is running (pid xxxx)

jQuery ajax error function

          cache: false,
          url: "addInterview_Code.asp",
          type: "POST",
          datatype: "text",
          data: strData,
          success: function (html) {
              alert('successful : ' + html);
          error: function(data, errorThrown)
              alert('request failed :'+errorThrown);

Java code for getting current time

try this:

final String currentTime    = String.valueOf(System.currentTimeMillis());

How to disable right-click context-menu in JavaScript

Capture the onContextMenu event, and return false in the event handler.

You can also capture the click event and check which mouse button fired the event with event.button, in some browsers anyway.

bundle install returns "Could not locate Gemfile"

Think more about what you are installing and navigate Gemfile folder, then try using sudo bundle install

Twitter Bootstrap 3 Sticky Footer

This has been solved by flexbox, once and forever:


<body class="Site">
  <main class="Site-content">…</main>


.Site {
  display: flex;
  min-height: 100vh;
  flex-direction: column;

.Site-content {
  flex: 1;

What's the proper way to "go get" a private repository?

For me, the solutions offered by others still gave the following error during go get

[email protected]: Permission denied (publickey). fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists.

What this solution required

  1. As stated by others:

    git config --global url."[email protected]:".insteadOf ""

  2. Removing the passphrase from my ./ssh/id_rsa key which was used for authenticating the connection to the repository. This can be done by entering an empty password when prompted as a response to:

    ssh-keygen -p

Why this works

This is not a pretty workaround as it is always better to have a passphrase on your private key, but it was causing issues somewhere inside OpenSSH.

go get uses internally git, which uses openssh to open the connection. OpenSSH takes the certs necessary for authentication from .ssh/id_rsa. When executing git commands from the command line an agent can take care of opening the id_rsa file for you so that you do not have to specify the passphrase every time, but when executed in the belly of go get, this did not work somewhy in my case. OpenSSH wants to prompt you then for a password but since it is not possible due to how it was called, it prints to its debug log:

read_passphrase: can't open /dev/tty: No such device or address

And just fails. If you remove the passphrase from the key file, OpenSSH will get to your key without that prompt and it works

This might be caused by Go fetching modules concurrently and opening multiple SSH connections to Github at the same time (as described in this article). This is somewhat supported by the fact that OpenSSH debug log showed the initial connection to the repository succeed, but later tried it again for some reason and this time opted to ask for a passphrase.

However the solution of using SSH connection multiplexing as put forward in the mentioned article did not work for me. For the record, the author suggested adding the collowing conf to the ssh config file for the affected host:

  ControlMaster auto
  ControlPersist 3600
  ControlPath ~/.ssh/%r@%h:%p

But as stated, for me it did not work, maybe I did it wrong

Highlight a word with jQuery

function hiliter(word, element) {
    var rgxp = new RegExp(word, 'g');
    var repl = '<span class="myClass">' + word + '</span>';
    element.innerHTML = element.innerHTML.replace(rgxp, repl);

how to generate a unique token which expires after 24 hours?

There are two possible approaches; either you create a unique value and store somewhere along with the creation time, for example in a database, or you put the creation time inside the token so that you can decode it later and see when it was created.

To create a unique token:

string token = Convert.ToBase64String(Guid.NewGuid().ToByteArray());

Basic example of creating a unique token containing a time stamp:

byte[] time = BitConverter.GetBytes(DateTime.UtcNow.ToBinary());
byte[] key = Guid.NewGuid().ToByteArray();
string token = Convert.ToBase64String(time.Concat(key).ToArray());

To decode the token to get the creation time:

byte[] data = Convert.FromBase64String(token);
DateTime when = DateTime.FromBinary(BitConverter.ToInt64(data, 0));
if (when < DateTime.UtcNow.AddHours(-24)) {
  // too old

Note: If you need the token with the time stamp to be secure, you need to encrypt it. Otherwise a user could figure out what it contains and create a false token.

How do I display the current value of an Android Preference in the Preference summary?

Android documentation says one can use a String formatting marker in getSummary():

If the summary has a String formatting marker in it (i.e. "%s" or "%1$s"), then the current entry value will be substituted in its place.

Simply specifying android:summary="Clean up messages after %s days" in ListPreference xml declaration worked for me.

Note: This only works for ListPreference.

Trim whitespace from a String

In addition to answer of @gjha:

inline std::string ltrim_copy(const std::string& str)
    auto it = std::find_if(str.cbegin(), str.cend(),
        [](char ch) { return !std::isspace<char>(ch, std::locale::classic()); });
    return std::string(it, str.cend());

inline std::string rtrim_copy(const std::string& str)
    auto it = std::find_if(str.crbegin(), str.crend(),
        [](char ch) { return !std::isspace<char>(ch, std::locale::classic()); });
    return it == str.crend() ? std::string() : std::string(str.cbegin(), ++it.base());

inline std::string trim_copy(const std::string& str)
    auto it1 = std::find_if(str.cbegin(), str.cend(),
        [](char ch) { return !std::isspace<char>(ch, std::locale::classic()); });
    if (it1 == str.cend()) {
        return std::string();
    auto it2 = std::find_if(str.crbegin(), str.crend(),
        [](char ch) { return !std::isspace<char>(ch, std::locale::classic()); });
    return it2 == str.crend() ? std::string(it1, str.cend()) : std::string(it1, ++it2.base());

"A namespace cannot directly contain members such as fields or methods"

The snippet you're showing doesn't seem to be directly responsible for the error.

This is how you can CAUSE the error:

namespace MyNameSpace

   class MyClass

If you don't immediately see what is "outside" the class, this may be due to misplaced or extra closing bracket(s) }.

Automatically scroll down chat div

I prefer to use Vanilla JS

let chatWrapper = document.querySelector('#chat-messages');
chatWrapper.scrollTo(0, chatWrapper.offsetHeight );

where element.scrollTo(x-coord, y-coord)

How to output numbers with leading zeros in JavaScript?


function pad(a, b){
  return(1e15 + a + '').slice(-b);

With comments:

function pad(
  a, // the number to convert 
  b // number of resulting characters
  return (
    1e15 + a + // combine with large number
    "" // convert to string
  ).slice(-b) // cut leading "1"

Simple CSS: Text won't center in a button

What about:

<input type="button" style="width:24px;" value="A"/>

Sorting list based on values from another list

I have created a more general function, that sorts more than two lists based on another one, inspired by @Whatang's answer.

def parallel_sort(*lists):
    Sorts the given lists, based on the first one.
    :param lists: lists to be sorted

    :return: a tuple containing the sorted lists

    # Create the initially empty lists to later store the sorted items
    sorted_lists = tuple([] for _ in range(len(lists)))

    # Unpack the lists, sort them, zip them and iterate over them
    for t in sorted(zip(*lists)):
        # list items are now sorted based on the first list
        for i, item in enumerate(t):    # for each item...
            sorted_lists[i].append(item)  # it in the appropriate list

    return sorted_lists

How do I create and access the global variables in Groovy?

def iamnotglobal=100 // This will not be accessible inside the function

iamglobal=200 // this is global and will be even available inside the 

def func()
{ "My value is 200. Here you see " + iamglobal
    // "if you uncomment me you will get error. Since iamnotglobal cant be printed here " + iamnotglobal
def func2()
{ "My value was changed inside func to 400 . Here it is = " + iamglobal

here iamglobal variable is a global variable used by func and then again available to func2

if you declare variable with def it will be local, if you don't use def its global

Two div blocks on same line

diplay:flex; is another alternative answer that you can add to all above answers which is supported in all modern browsers.

#block_container {_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
<div id="block_container">_x000D_
  <div id="bloc1">Copyright &copy; All Rights Reserved.</div>_x000D_
  <div id="bloc2"><img src="..."></div>_x000D_

Why doesn't margin:auto center an image?

Because your image is an inline-block element. You could change it to a block-level element like this:

<img src="queuedError.jpg" style="margin:auto; width:200px;display:block" />

and it will be centered.

What is the Python 3 equivalent of "python -m SimpleHTTPServer"

In one of my projects I run tests against Python 2 and 3. For that I wrote a small script which starts a local server independently:

$ python -m $(python -c 'import sys; print("http.server" if sys.version_info[:2] > (2,7) else "SimpleHTTPServer")')
Serving HTTP on port 8000 ...

As an alias:

$ alias serve="python -m $(python -c 'import sys; print("http.server" if sys.version_info[:2] > (2,7) else "SimpleHTTPServer")')"
$ serve
Serving HTTP on port 8000 ...

Please note that I control my Python version via conda environments, because of that I can use python instead of python3 for using Python 3.

How many files can I put in a directory?

The question comes down to what you're going to do with the files.

Under Windows, any directory with more than 2k files tends to open slowly for me in Explorer. If they're all image files, more than 1k tend to open very slowly in thumbnail view.

At one time, the system-imposed limit was 32,767. It's higher now, but even that is way too many files to handle at one time under most circumstances.

In practice, what are the main uses for the new "yield from" syntax in Python 3.3?

This code defines a function fixed_sum_digits returning a generator enumerating all six digits numbers such that the sum of digits is 20.

def iter_fun(sum, deepness, myString, Total):
    if deepness == 0:
        if sum == Total:
            yield myString
        for i in range(min(10, Total - sum + 1)):
            yield from iter_fun(sum + i,deepness - 1,myString + str(i),Total)

def fixed_sum_digits(digits, Tot):
    return iter_fun(0,digits,"",Tot) 

Try to write it without yield from. If you find an effective way to do it let me know.

I think that for cases like this one: visiting trees, yield from makes the code simpler and cleaner.

Replace HTML Table with Divs

Please be aware that although tables are discouraged as a primary means of page layout, they still have their place. Tables can and should be used when and where appropriate and until some of the more popular browsers (ahem, IE, ahem) become more standards compliant, tables are sometimes the best route to a solution.

Difference between two lists

bit late but here is working solution for me

 var myBaseProperty = (typeof(BaseClass)).GetProperties();//get base code properties
                    var allProperty = entity.GetProperties()[0].DeclaringType.GetProperties();//get derived class property plus base code as it is derived from it
                    var declaredClassProperties = allProperty.Where(x => !myBaseProperty.Any(l => l.Name == x.Name)).ToList();//get the difference

In above mention code I am getting the properties difference between my base class and derived class list

Jenkins pipeline how to change to another folder

The dir wrapper can wrap, any other step, and it all works inside a steps block, for example:

steps {
    sh "pwd"
    dir('your-sub-directory') {
      sh "pwd"
    sh "pwd"

What is the "Illegal Instruction: 4" error and why does "-mmacosx-version-min=10.x" fix it?

In my case, I got this while overloading

ostream & operator << (ostream &out, const MyClass &obj)

and forgot to return out. In other systems this just generates a warning, but on macos it also generated an error (although it seems to print correctly).

The error was resolved by adding the correct return value. In my case, adding the -mmacosx-version-min flag had no effect.

mysql: SOURCE error 2?

For Mac users, you can give the path as,

source /Users/YOUR_USER_NAME/Desktop/metropolises.sql;

*I have assumed that the file you need to source is in your desktop and the file name is metropolises.sql

If you type,

source metropolises.sql

then the file will be look in the default location,


npm command to uninstall or prune unused packages in Node.js

Note: Recent npm versions do this automatically when package-locks are enabled, so this is not necessary except for removing development packages with the --production flag.

Run npm prune to remove modules not listed in package.json.

From npm help prune:

This command removes "extraneous" packages. If a package name is provided, then only packages matching one of the supplied names are removed.

Extraneous packages are packages that are not listed on the parent package's dependencies list.

If the --production flag is specified, this command will remove the packages specified in your devDependencies.

Different font size of strings in the same TextView

I have written my own function which takes 2 strings and 1 int (text size)

The full text and the part of the text you want to change the size of it.

It returns a SpannableStringBuilder which you can use it in text view.

  public static SpannableStringBuilder setSectionOfTextSize(String text, String textToChangeSize, int size){

        SpannableStringBuilder builder=new SpannableStringBuilder();

        if(textToChangeSize.length() > 0 && !textToChangeSize.trim().equals("")){

            //for counting start/end indexes
            String testText = text.toLowerCase(Locale.US);
            String testTextToBold = textToChangeSize.toLowerCase(Locale.US);
            int startingIndex = testText.indexOf(testTextToBold);
            int endingIndex = startingIndex + testTextToBold.length();
            //for counting start/end indexes

            if(startingIndex < 0 || endingIndex <0){
                return builder.append(text);
            else if(startingIndex >= 0 && endingIndex >=0){

                builder.setSpan(new AbsoluteSizeSpan(size, true), startingIndex, endingIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            return builder.append(text);

        return builder;

Calculate the mean by group

Adding alternative base R approach, which remains fast under various cases.

rowsummean <- function(df) {
  rowsum(df$speed, df$dive) / tabulate(df$dive)

Borrowing the benchmarks from @Ari:

10 rows, 2 groups


10 million rows, 10 groups


10 million rows, 1000 groups


How do I grant myself admin access to a local SQL Server instance?

Its actually enough to add -m to startup parameters on Sql Server Configuration Manager, restart service, go to ssms an add checkbox sysadmin on your account, then remove -m restart again and use as usual.

Database Engine Service Startup Options

-m Starts an instance of SQL Server in single-user mode.

TokenMismatchException in VerifyCsrfToken.php Line 67

Your form method is post. So open the Middleware/VerifyCsrfToken .php file , find the isReading() method and add 'POST' method in array.

jQuery replace one class with another

Starting with the HTML fragment:

<div class='helpTop ...

use the javaScript fragment:


How to check String in response body with mockMvc

String body = mockMvc.perform(bla... bla).andReturn().getResolvedException().getMessage()

This should give you the body of the response. "Username already taken" in your case.

Radio buttons and label to display in same line

If you use the HTML structure I lay out in this question you can simply float your label and input to the left and adjust padding/margin until things are lined up.

And yes, you'll want to make your radio button have a class name for old IE. And to have all of them on the same line, according to the markup I linked to above, it would be like so:

fieldset {_x000D_
      overflow: hidden_x000D_
    .some-class {_x000D_
      float: left;_x000D_
      clear: none;_x000D_
    label {_x000D_
      float: left;_x000D_
      clear: none;_x000D_
      display: block;_x000D_
      padding: 0px 1em 0px 8px;_x000D_
    input[type=radio],_x000D_ {_x000D_
      float: left;_x000D_
      clear: none;_x000D_
      margin: 2px 0 0 2px;_x000D_
      <div class="some-class">_x000D_
        <input type="radio" class="radio" name="x" value="y" id="y" />_x000D_
        <label for="y">Thing 1</label>_x000D_
        <input type="radio" class="radio" name="x" value="z" id="z" />_x000D_
        <label for="z">Thing 2</label>_x000D_

Renew Provisioning Profile

They've changed it now. (Oct 2010)

  1. Log into iPhone developer website:

  2. Then click on "Provisioning Portal" on the right hand sidebar menu (right at the top).

  3. On the next page click "Provisioning" in the left sidebar menu

  4. Then you'll see your provisioning profile/s, and the 'renew' button/s - Press it :)

Broadcast Receiver within a Service

The better pattern is to create a standalone BroadcastReceiver. This insures that your app can respond to the broadcast, whether or not the Service is running. In fact, using this pattern may remove the need for a constant-running Service altogether.

Register the BroadcastReceiver in your Manifest, and create a separate class/file for it.


<receiver android:name=".FooReceiver" >
    <intent-filter >
        <action android:name="android.provider.Telephony.SMS_RECEIVED" />

When the receiver runs, you simply pass an Intent (Bundle) to the Service, and respond to it in onStartCommand().


public class FooReceiver extends BroadcastReceiver {
    public void onReceive(Context context, Intent intent) {
        // do your work quickly!
        // then call context.startService();

Upload Progress Bar in PHP

Implementation of the upload progress bar is easy and doesn't require any additional PHP extension, JavaScript or Flash. But you need PHP 5.4 and newer.

You have to enable collecting of the upload progress information by setting the directive session.upload_progress.enabled to On in php.ini.

Then add a hidden input to the HTML upload form just before any other file inputs. HTML attribute name of that hidden input should be the same as the value of the directive from php.ini (eventually preceded by session.upload_progress.prefix). The value attribute is up to you, it will be used as part of the session key.

HTML form could looks like this:

<form action="upload.php" method="POST" enctype="multipart/form-data">
   <input type="hidden" name="<?php echo ini_get('session.upload_progress.prefix').ini_get(''); ?>" value="myupload" />
   <input type="file" name="file1" />
   <input type="submit" />

When you send this form, PHP should create a new key in the $_SESSION superglobal structure which will be populated with the upload status information. The key is concatenated name and value of the hidden input.

In PHP you can take a look at populated upload information:


The output will look similarly to the following:

$_SESSION["upload_progress_myupload"] = array(
  "start_time" => 1234567890,   // The request time
  "content_length" => 57343257, // POST content length
  "bytes_processed" => 54321,   // Amount of bytes received and processed
  "done" => false,              // true when the POST handler has finished, successfully or not
  "files" => array(
    0 => array(
      "field_name" => "file1",    // Name of the <input /> field
      // The following 3 elements equals those in $_FILES
      "name" => "filename.ext",
      "tmp_name" => "/tmp/phpxxxxxx",
      "error" => 0,
      "done" => false,            // True when the POST handler has finished handling this file
      "start_time" => 1234567890, // When this file has started to be processed
      "bytes_processed" => 54321, // Number of bytes received and processed for this file

There is all the information needed to create a progress bar — you have the information if the upload is still in progress, the information how many bytes is going to be transferred in total and how many bytes has been transferred already.

To present the upload progress to the user, write an another PHP script than the uploading one, which will only look at the upload information in the session and return it in the JSON format, for example. This script can be called periodically, for example every second, using AJAX and information presented to the user.

You are even able to cancel the upload by setting the $_SESSION[$key]['cancel_upload'] to true.

For detailed information, additional settings and user's comments see PHP manual.

PHP Array to CSV

In my case, my array was multidimensional, potentially with arrays as values. So I created this recursive function to blow apart the array completely:

function array2csv($array, &$title, &$data) {
    foreach($array as $key => $value) {      
        if(is_array($value)) {
            $title .= $key . ",";
            $data .= "" . ",";
            array2csv($value, $title, $data);
        } else {
            $title .= $key . ",";
            $data .= '"' . $value . '",';

Since the various levels of my array didn't lend themselves well to a the flat CSV format, I created a blank column with the sub-array's key to serve as a descriptive "intro" to the next level of data. Sample output:

agentid     fname           lname      empid    totals  sales   leads   dish    dishnet top200_plus top120  latino  base_packages
G-adriana   ADRIANA EUGENIA PALOMO PAIZ 886                0    19              0         0         0         0      0

You could easily remove that "intro" (descriptive) column, but in my case I had repeating column headers, i.e. inbound_leads, in each sub-array, so that gave me a break/title preceding the next section. Remove:

$title .= $key . ",";
$data .= "" . ",";

after the is_array() to compact the code further and remove the extra column.

Since I wanted both a title row and data row, I pass two variables into the function and upon completion of the call to the function, terminate both with PHP_EOL:

$title .= PHP_EOL;
$data .= PHP_EOL;

Yes, I know I leave an extra comma, but for the sake of brevity, I didn't handle it here.

How to sort an array in descending order in Ruby

Simple Solution from ascending to descending and vice versa is:


str = ['ravi', 'aravind', 'joker', 'poker']
asc_string = str.sort # => ["aravind", "joker", "poker", "ravi"]
asc_string.reverse # => ["ravi", "poker", "joker", "aravind"]


digit = [234,45,1,5,78,45,34,9]
asc_digit = digit.sort # => [1, 5, 9, 34, 45, 45, 78, 234]
asc_digit.reverse # => [234, 78, 45, 45, 34, 9, 5, 1]

How to spyOn a value property (rather than a method) with Jasmine

I'm a bit late to the party here i know but,

You could directly access the calls object, which can give you the variables for each call