Programs & Examples On #Model based testing

Failed to instantiate module [$injector:unpr] Unknown provider: $routeProvider

In my case it was because the file was minified with wrong scope. Use Array!

app.controller('StoreController', ['$http', function($http) {

Coffee syntax:

app.controller 'StoreController', Array '$http', ($http) ->

Path of assets in CSS files in Symfony 2

If it can help someone, we have struggled a lot with Assetic, and we are now doing the following in development mode:

  • Set up like in Dumping Asset Files in the dev Environmen so in config_dev.yml, we have commented:

    #    use_controller: true

    And in routing_dev.yml

    #    resource: .
    #    type:     assetic
  • Specify the URL as absolute from the web root. For example, background-image: url("/bundles/core/dynatree/skins/skin/vline.gif"); Note: our vhost web root is pointing on web/.

  • No usage of cssrewrite filter

Using Pandas to pd.read_excel() for multiple worksheets of the same workbook

You can also use the index for the sheet:

xls = pd.ExcelFile('path_to_file.xls')
sheet1 = xls.parse(0)

will give the first worksheet. for the second worksheet:

sheet2 = xls.parse(1)

What's the purpose of the LEA instruction?

The LEA (Load Effective Address) instruction is a way of obtaining the address which arises from any of the Intel processor's memory addressing modes.

That is to say, if we have a data move like this:


it moves the contents of the designated memory location into the target register.

If we replace the MOV by LEA, then the address of the memory location is calculated in exactly the same way by the <MEM-OPERAND> addressing expression. But instead of the contents of the memory location, we get the location itself into the destination.

LEA is not a specific arithmetic instruction; it is a way of intercepting the effective address arising from any one of the processor's memory addressing modes.

For instance, we can use LEA on just a simple direct address. No arithmetic is involved at all:

MOV EAX, GLOBALVAR   ; fetch the value of GLOBALVAR into EAX
LEA EAX, GLOBALVAR   ; fetch the address of GLOBALVAR into EAX.

This is valid; we can test it at the Linux prompt:

$ as
LEA 0, %eax
$ objdump -d a.out

a.out:     file format elf64-x86-64

Disassembly of section .text:

0000000000000000 <.text>:
   0:   8d 04 25 00 00 00 00    lea    0x0,%eax

Here, there is no addition of a scaled value, and no offset. Zero is moved into EAX. We could do that using MOV with an immediate operand also.

This is the reason why people who think that the brackets in LEA are superfluous are severely mistaken; the brackets are not LEA syntax but are part of the addressing mode.

LEA is real at the hardware level. The generated instruction encodes the actual addressing mode and the processor carries it out to the point of calculating the address. Then it moves that address to the destination instead of generating a memory reference. (Since the address calculation of an addressing mode in any other instruction has no effect on CPU flags, LEA has no effect on CPU flags.)

Contrast with loading the value from address zero:

$ as
movl 0, %eax
$ objdump -d a.out | grep mov
   0:   8b 04 25 00 00 00 00    mov    0x0,%eax

It's a very similar encoding, see? Just the 8d of LEA has changed to 8b.

Of course, this LEA encoding is longer than moving an immediate zero into EAX:

$ as
movl $0, %eax
$ objdump -d a.out | grep mov
   0:   b8 00 00 00 00          mov    $0x0,%eax

There is no reason for LEA to exclude this possibility though just because there is a shorter alternative; it's just combining in an orthogonal way with the available addressing modes.

How can I enable CORS on Django REST Framework

You can do by using a custom middleware, even though knowing that the best option is using the tested approach of the package django-cors-headers. With that said, here is the solution:

create the following structure and files:

-- myapp/middleware/

from corsMiddleware import corsMiddleware

-- myapp/middleware/

class corsMiddleware(object):
    def process_response(self, req, resp):
        resp["Access-Control-Allow-Origin"] = "*"
        return resp

add to the marked line:


    # Now we add here our custom middleware
     'app_name.middleware.corsMiddleware' <---- this line

How to generate a random number in C++?

Using modulo may introduce bias into the random numbers, depending on the random number generator. See this question for more info. Of course, it's perfectly possible to get repeating numbers in a random sequence.

Try some C++11 features for better distribution:

#include <random>
#include <iostream>

int main()
    std::random_device dev;
    std::mt19937 rng(dev());
    std::uniform_int_distribution<std::mt19937::result_type> dist6(1,6); // distribution in range [1, 6]

    std::cout << dist6(rng) << std::endl;

See this question/answer for more info on C++11 random numbers. The above isn't the only way to do this, but is one way.

html table cell width for different rows

One solution would be to divide your table into 20 columns of 5% width each, then use colspan on each real column to get the desired width, like this:

<body bgcolor="#14B3D9">_x000D_
<table width="100%" border="1" bgcolor="#ffffff">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <col width="5%"><col width="5%">_x000D_
        <td colspan=5>25</td>_x000D_
        <td colspan=10>50</td>_x000D_
        <td colspan=5>25</td>_x000D_
        <td colspan=10>50</td>_x000D_
        <td colspan=6>30</td>_x000D_
        <td colspan=4>20</td>_x000D_


Error in : figure margins too large, Scatter plot

Just clear the plots and try executing the code again...It worked for me

When should you use 'friend' in C++?

When implementing tree algorithms for class, the framework code the prof gave us had the tree class as a friend of the node class.

It doesn't really do any good, other than let you access a member variable without using a setting function.

how to put focus on TextBox when the form load?

check your tab order and make sure the textbox is set to zero

How do I set a VB.Net ComboBox default value

Just go to the combo box properties - DropDownStyle and change it to "DropDownList"

This will make visible the first item.

Javascript add method to object

There are many ways to create re-usable objects like this in JavaScript. Mozilla have a nice introduction here:

The following will work in your example:

function Foo(){ = function (){
        alert("Hello World!");

myFoo = new Foo();; // Hello World?????????????????????????????????

FIFO class in Java

Not sure what you call FIFO these days since Queue is FILO, but when I was a student we used the Stack<E> with the simple push, pop, and a peek... It is really that simple, no need for complicating further with Queue and whatever the accepted answer suggests.

CSS to make table 100% of max-width

I had the same issue it was due to that I had the bootstrap class "hidden-lg" on the table which caused it to stupidly become display: block !important;

I wonder how Bootstrap never considered to just instead do this:

@media (min-width: 1200px) {
    .hidden-lg {
         display: none;

And then just leave the element whatever display it had before for other screensizes.. Perhaps it is too advanced for them to figure out..

Anyway so:

table {
    display: table; /* check so these really applies */
    width: 100%;

should work

Button that refreshes the page on click

Only this realy reloads page (Today)

<input type="button" value="Refresh Page" onClick="location.href=location.href">

Others do not exactly reload. They keep values inside text boxes.

What are the differences between Deferred, Promise and Future in JavaScript?

  • A promise represents a value that is not yet known
  • A deferred represents work that is not yet finished

A promise is a placeholder for a result which is initially unknown while a deferred represents the computation that results in the value.


get an element's id

Super Easy Way is

  $('.CheckBxMSG').each(function () {
            var ChkBxMsgId;
            ChkBxMsgId = $(this).attr('id');

Tell me if this helps

How can you print a variable name in python?

If you are trying to do this, it means you are doing something wrong. Consider using a dict instead.

def show_val(vals, name):
    print "Name:", name, "val:", vals[name]

vals = {'a': 1, 'b': 2}
show_val(vals, 'b')


Name: b val: 2

In Angular, how do you determine the active route?

Solution for Angular2 RC 4:

import {containsTree} from '@angular/router/src/url_tree';
import {Router} from '@angular/router';

export function isRouteActive(router: Router, route: string) {
   const currentUrlTree = router.parseUrl(router.url);
   const routeUrlTree = router.createUrlTree([route]);
   return containsTree(currentUrlTree, routeUrlTree, true);

Replace a character at a specific index in a string?

As previously answered here, String instances are immutable. StringBuffer and StringBuilder are mutable and suitable for such a purpose whether you need to be thread safe or not.

There is however a way to modify a String but I would never recommend it because it is unsafe, unreliable and it can can be considered as cheating : you can use reflection to modify the inner char array the String object contains. Reflection allows you to access fields and methods that are normally hidden in the current scope (private methods or fields from another class...).

public static void main(String[] args) {
    String text = "This is a test";
    try {
        //String.value is the array of char (char[])
        //that contains the text of the String
        Field valueField = String.class.getDeclaredField("value");
        //String.value is a private variable so it must be set as accessible 
        //to read and/or to modify its value
        //now we get the array the String instance is actually using
        char[] value = (char[])valueField.get(text);
        //The 13rd character is the "s" of the word "Test"
        //We display the string which should be "This is a text"
    } catch (NoSuchFieldException | SecurityException e) {
    } catch (IllegalArgumentException e) {
    } catch (IllegalAccessException e) {

What is the preferred/idiomatic way to insert into a map?

In short, [] operator is more efficient for updating values because it involves calling default constructor of the value type and then assigning it a new value, while insert() is more efficient for adding values.

The quoted snippet from Effective STL: 50 Specific Ways to Improve Your Use of the Standard Template Library by Scott Meyers, Item 24 might help.

template<typename MapType, typename KeyArgType, typename ValueArgType>
typename MapType::iterator
insertKeyAndValue(MapType& m, const KeyArgType&k, const ValueArgType& v)
    typename MapType::iterator lb = m.lower_bound(k);

    if (lb != m.end() && !(m.key_comp()(k, lb->first))) {
        lb->second = v;
        return lb;
    } else {
        typedef typename MapType::value_type MVT;
        return m.insert(lb, MVT(k, v));

You may decide to choose a generic-programming-free version of this, but the point is that I find this paradigm (differentiating 'add' and 'update') extremely useful.

If strings starts with in PowerShell

$Group is an object, but you will actually need to check if $Group.samaccountname.StartsWith("string").

Change $Group.StartsWith("S_G_") to $Group.samaccountname.StartsWith("S_G_").

How to convert a date String to a Date or Calendar object?

In brief:

DateFormat formatter = new SimpleDateFormat("MM/dd/yy");
try {
  Date date = formatter.parse("01/29/02");
} catch (ParseException e) {

See SimpleDateFormat javadoc for more.

And to turn it into a Calendar, do:

Calendar calendar = Calendar.getInstance();

How to resolve git's "not something we can merge" error

I had a work tree with master and an another branch checked out in two different work folders.

PS C:\rhipheusADO\Build> git worktree list
C:/rhipheusADO/Build         7d32e6e [vyas-cr-core]
C:/rhipheusADO/Build-master  91d418c [master]

PS C:\rhipheusADO\Build> cd ..\Build-master\

PS C:\rhipheusADO\Build-master> git merge 7d32e6e #Or any other intermediary commits
Updating 91d418c..7d32e6e
 Pipeline/CR-MultiPool/azure-pipelines-auc.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

PS C:\rhipheusADO\Build-master> git ls-remote
53060bac18f9d4e7c619e5170c436e6049b63f25        HEAD
7d32e6ec76d5a5271caebc2555d5a3a84b703954        refs/heads/vyas-cr-core 

PS C:\rhipheusADO\Build-master> git merge 7d32e6ec76d5a5271caebc2555d5a3a84b703954
Already up-to-date

PS C:\rhipheusADO\Build>  git push
Total 0 (delta 0), reused 0 (delta 0)
   91d418c..7d32e6e  master -> master

If you need to just merge the latest commit:

git merge origin/vyas-cr-core 
git push

And is same as what I've always done:

git checkout master # This is needed if you're not using worktrees
git pull origin vyas-cr-core
git push

mailto link multiple body lines

You can use URL encoding to encode the newline as %0A.

mailto:emai[email protected]?subject=test&body=type%20your%0Amessage%20here

While the above appears to work in many cases, user olibre points out that the RFC governing the mailto URI scheme specifies that %0D%0A (carriage return + line feed) should be used instead of %0A (line feed). See also: Newline Representations.

Python Hexadecimal

Another solution is:

>>> "".join(list(hex(255))[2:])

Probably an archaic answer, but functional.

How to upload and parse a CSV file in php

Although you could easily find a tutorial how to handle file uploads with php, and there are functions (manual) to handle CSVs, I will post some code because just a few days ago I worked on a project, including a bit of code you could use...


<table width="600">
<form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="post" enctype="multipart/form-data">

<td width="20%">Select file</td>
<td width="80%"><input type="file" name="file" id="file" /></td>

<td><input type="submit" name="submit" /></td>



if ( isset($_POST["submit"]) ) {

   if ( isset($_FILES["file"])) {

            //if there was an error uploading the file
        if ($_FILES["file"]["error"] > 0) {
            echo "Return Code: " . $_FILES["file"]["error"] . "<br />";

        else {
                 //Print file details
             echo "Upload: " . $_FILES["file"]["name"] . "<br />";
             echo "Type: " . $_FILES["file"]["type"] . "<br />";
             echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
             echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";

                 //if file already exists
             if (file_exists("upload/" . $_FILES["file"]["name"])) {
            echo $_FILES["file"]["name"] . " already exists. ";
             else {
                    //Store file in directory "upload" with the name of "uploaded_file.txt"
            $storagename = "uploaded_file.txt";
            move_uploaded_file($_FILES["file"]["tmp_name"], "upload/" . $storagename);
            echo "Stored in: " . "upload/" . $_FILES["file"]["name"] . "<br />";
     } else {
             echo "No file selected <br />";

I know there must be an easier way to do this, but I read the CSV file and store the single cells of every record in an two dimensional array.

if ( isset($storagename) && $file = fopen( "upload/" . $storagename , r ) ) {

    echo "File opened.<br />";

    $firstline = fgets ($file, 4096 );
        //Gets the number of fields, in CSV-files the names of the fields are mostly given in the first line
    $num = strlen($firstline) - strlen(str_replace(";", "", $firstline));

        //save the different fields of the firstline in an array called fields
    $fields = array();
    $fields = explode( ";", $firstline, ($num+1) );

    $line = array();
    $i = 0;

        //CSV: one line is one record and the cells/fields are seperated by ";"
        //so $dsatz is an two dimensional array saving the records like this: $dsatz[number of record][number of cell]
    while ( $line[$i] = fgets ($file, 4096) ) {

        $dsatz[$i] = array();
        $dsatz[$i] = explode( ";", $line[$i], ($num+1) );


        echo "<table>";
        echo "<tr>";
    for ( $k = 0; $k != ($num+1); $k++ ) {
        echo "<td>" . $fields[$k] . "</td>";
        echo "</tr>";

    foreach ($dsatz as $key => $number) {
                //new table row for every record
        echo "<tr>";
        foreach ($number as $k => $content) {
                        //new table cell for every field of the record
            echo "<td>" . $content . "</td>";

    echo "</table>";

So I hope this will help, it is just a small snippet of code and I have not tested it, because I used it slightly different. The comments should explain everything.

What is the difference between Visual Studio Express 2013 for Windows and Visual Studio Express 2013 for Windows Desktop?

More importantly, the 2013 versions of Visual Studio Express have all the languages that comes with the commercial versions. You can use the Windows desktop versions not only to program using Windows Forms, it is possible to write those windowed applications with any language that comes with the software, may it be C++ using the windows.h header if you want to actually learn how to create windows applications from scratch, or use Windows form to create windows in C# or visual Basic.

In the past, you had to download one version for each language or type of content. Or just download an all-in-one that still installed separate versions of the software for different languages. Now with 2013 you get all the languages needed in each content oriented version of the 2013 express.

You pick what matters the most to you.

Besides, it might be a good way to learn using notepad and the command line to write and compile, but I find that a bit tedious to use. While using an IDE might be overwhelming at first, you start small, learning how to create a project, write code, compile your code. They have gone way over their heads to ease up your day when you take it for the first time.

How can I push a specific commit to a remote, and not previous commits?

To push up through a given commit, you can write:

git push <remotename> <commit SHA>:<remotebranchname>

provided <remotebranchname> already exists on the remote. (If it doesn't, you can use git push <remotename> <commit SHA>:refs/heads/<remotebranchname> to autocreate it.)

If you want to push a commit without pushing previous commits, you should first use git rebase -i to re-order the commits.

How can I create a dynamic button click event on a dynamic button?

Let's say you have 25 objects and want one process to handle any one objects click event. You could write 25 delegates or use a loop to handle the click event.

public form1()
    foreach (Panel pl  in Container.Components)
        pl.Click += Panel_Click;

private void Panel_Click(object sender, EventArgs e)
    // Process the panel clicks here
    int index = Panels.FindIndex(a => a == sender);

How do I get monitor resolution in Python?

To get bits per pixel:

import ctypes
user32 = ctypes.windll.user32
gdi32 = ctypes.windll.gdi32

screensize = (user32.GetSystemMetrics(0), user32.GetSystemMetrics(1))
print "screensize =%s"%(str(screensize))
dc = user32.GetDC(None);

screensize = (gdi32.GetDeviceCaps(dc,8), gdi32.GetDeviceCaps(dc,10), gdi32.GetDeviceCaps(dc,12))
print "screensize =%s"%(str(screensize))
screensize = (gdi32.GetDeviceCaps(dc,118), gdi32.GetDeviceCaps(dc,117), gdi32.GetDeviceCaps(dc,12))
print "screensize =%s"%(str(screensize))

parameters in gdi32:

#/// Vertical height of entire desktop in pixels
#/// Horizontal width of entire desktop in pixels
#/// Horizontal width in pixels
#/// Vertical height in pixels
#VERTRES = 10,
#/// Number of bits per pixel

C# "as" cast vs classic cast

Null comparison is MUCH faster than throwing and catching exception. Exceptions have significant overhead - stack trace must be assembled etc.

Exceptions should represent an unexpected state, which often doesn't represent the situation (which is when as works better).

How do I convert Word files to PDF programmatically?

Easy code and solution using Microsoft.Office.Interop.Word to converd WORD in PDF

using Word = Microsoft.Office.Interop.Word;

private void convertDOCtoPDF()

  object misValue = System.Reflection.Missing.Value;
  String  PATH_APP_PDF = @"c:\..\MY_WORD_DOCUMENT.pdf"

  var WORD = new Word.Application();

  Word.Document doc   = WORD.Documents.Open(@"c:\..\MY_WORD_DOCUMENT.docx");

  doc.SaveAs2(@PATH_APP_PDF, Word.WdSaveFormat.wdFormatPDF, misValue, misValue, misValue, 
  misValue, misValue, misValue, misValue, misValue, misValue, misValue);




Add this procedure to release memory:

private void releaseObject(object obj)
      obj = null;
  catch (Exception ex)

SQLite error 'attempt to write a readonly database' during insert?

This can be caused by SELinux. If you don't want to disable SELinux completely, you need to set the db directory fcontext to httpd_sys_rw_content_t.

semanage fcontext -a -t httpd_sys_rw_content_t "/var/www/railsapp/db(/.*)?"
restorecon -v /var/www/railsapp/db

How to query values from xml nodes?

if you have only one xml in your table, you can convert it in 2 steps:

   BatchID int,
   RawXml xml 

declare @xml xml=(select top 1 RawXml from @Batches)

SELECT  --b.BatchID,
        x.XmlCol.value('(ReportHeader/OrganizationReportReferenceIdentifier)[1]','VARCHAR(100)') AS OrganizationReportReferenceIdentifier,
        x.XmlCol.value('(ReportHeader/OrganizationNumber)[1]','VARCHAR(100)') AS OrganizationNumber
FROM    @xml.nodes('/CasinoDisbursementReportXmlFile/CasinoDisbursementReport') x(XmlCol)

ImportError: No module named xlsxwriter

I have the same issue. It seems that pip is the problem. Try

pip uninstall xlsxwriter
easy_install xlsxwriter

Setting paper size in FPDF

They say it right there in the documentation for the FPDF constructor:

FPDF([string orientation [, string unit [, mixed size]]])

This is the class constructor. It allows to set up the page size, the orientation and the unit of measure used in all methods (except for font sizes). Parameters ...


The size used for pages. It can be either one of the following values (case insensitive):

A3 A4 A5 Letter Legal

or an array containing the width and the height (expressed in the unit given by unit).

They even give an example with custom size:

Example with a custom 100x150 mm page size:

$pdf = new FPDF('P','mm',array(100,150));

How do I get the file extension of a file in Java?

If you use Spring framework in your project, then you can use StringUtils

import org.springframework.util.StringUtils;


How do I make UITableViewCell's ImageView a fixed size even when the image is smaller

Here is @germanattanasio 's working method, written for Swift 3

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    cell.imageView?.image = myImage
    let itemSize = CGSize(width:42.0, height:42.0)
    UIGraphicsBeginImageContextWithOptions(itemSize, false, 0.0)
    let imageRect = CGRect(x:0.0, y:0.0, width:itemSize.width, height:itemSize.height)
    cell.imageView?.image! = UIGraphicsGetImageFromCurrentImageContext()!

How to find unused/dead code in java projects

In theory, you can't deterministically find unused code. Theres a mathematical proof of this (well, this is a special case of a more general theorem). If you're curious, look up the Halting Problem.

This can manifest itself in Java code in many ways:

  • Loading classes based on user input, config files, database entries, etc;
  • Loading external code;
  • Passing object trees to third party libraries;
  • etc.

That being said, I use IDEA IntelliJ as my IDE of choice and it has extensive analysis tools for findign dependencies between modules, unused methods, unused members, unused classes, etc. Its quite intelligent too like a private method that isn't called is tagged unused but a public method requires more extensive analysis.

Set focus to field in dynamically loaded DIV



is not working then is there another element on your page with the id of header?

Use firebug to run $("#header") and see what it returns.

How can I login to a website with Python?

For HTTP things, the current choice should be: Requests- HTTP for Humans

Angular - "has no exported member 'Observable'"

What helped me is:

  1. Get rid of all old import paths and replace them with new ones like this:

    import { Observable , BehaviorSubject } from 'rxjs';)

  2. Delete node_modules folder

  3. npm cache verify
  4. npm install

How to connect to MongoDB in Windows?

you can use below command,

mongod --dbpath=D:\home\mongodata

where D:\home\mongodata is the data storage path

How to execute IN() SQL queries with Spring's JDBCTemplate effectively?

I do the "in clause" query with spring jdbc like this:

String sql = "SELECT bg.goodsid FROM beiker_goods bg WHERE bg.goodsid IN (:goodsid)";

List ids = Arrays.asList(new Integer[]{12496,12497,12498,12499});
Map<String, List> paramMap = Collections.singletonMap("goodsid", ids);
NamedParameterJdbcTemplate template = 
    new NamedParameterJdbcTemplate(getJdbcTemplate().getDataSource());

List<Long> list = template.queryForList(sql, paramMap, Long.class);

Windows batch: formatted date into variable

Use date /T to find the format on command prompt.

If the date format is Thu 17/03/2016 use like this:

set datestr=%date:~10,4%-%date:~7,2%-%date:~4,2%
echo %datestr%

Meaning of ${project.basedir} in pom.xml

There are a set of available properties to all Maven projects.

From Introduction to the POM:

project.basedir: The directory that the current project resides in.

This means this points to where your Maven projects resides on your system. It corresponds to the location of the pom.xml file. If your POM is located inside /path/to/project/pom.xml then this property will evaluate to /path/to/project.

Some properties are also inherited from the Super POM, which is the case for It is the value inside the <project><build><directory> element of the POM. You can get a description of all those values by looking at the Maven model. For, it is:

The directory where all files generated by the build are placed. The default value is target.

This is the directory that will hold every generated file by the build.

What does it mean when the size of a VARCHAR2 in Oracle is declared as 1 byte?

You can declare columns/variables as varchar2(n CHAR) and varchar2(n byte).

n CHAR means the variable will hold n characters. In multi byte character sets you don't always know how many bytes you want to store, but you do want to garantee the storage of a certain amount of characters.

n bytes means simply the number of bytes you want to store.

varchar is deprecated. Do not use it. What is the difference between varchar and varchar2?

Get text of the selected option with jQuery

Also u can consider this


which might be a little faster solution though I am not sure.

SQL Server: Attach incorrect version 661

To clarify, a database created under SQL Server 2008 R2 was being opened in an instance of SQL Server 2008 (the version prior to R2). The solution for me was to simply perform an upgrade installation of SQL Server 2008 R2. I can only speak for the Express edition, but it worked.

Oddly, though, the Web Platform Installer indicated that I had Express R2 installed. The better way to tell is to ask the database server itself:


How to parse a JSON Input stream

use jackson to convert json input stream to the map or object

there are also some other usefull libraries for json, you can google: json java

Binding IIS Express to an IP Address

In order for IIS Express answer on any IP address, just leave the address blank, i.e:


Don't forget to restart the IIS express before the changes can take place.

How to fix '.' is not an internal or external command error

This error comes when using the following command in Windows. You can simply run the following command by removing the dot '.' and the slash '/'.

Instead of writing:

D:\Gesture Recognition\Gesture Recognition\Debug>./"Gesture Recognition.exe"


D:\Gesture Recognition\Gesture Recognition\Debug>"Gesture Recognition.exe"

How to set an environment variable only for the duration of the script?

Just put

export HOME=/blah/whatever

at the point in the script where you want the change to happen. Since each process has its own set of environment variables, this definition will automatically cease to have any significance when the script terminates (and with it the instance of bash that has a changed environment).

JavaScript - Get Browser Height

The way that I like to do it is like this with a ternary assignment.

 var width = isNaN(window.innerWidth) ? window.clientWidth : window.innerWidth;
 var height = isNaN(window.innerHeight) ? window.clientHeight : window.innerHeight;

I might point out that, if you run this in the global context that from that point on you could use window.height and window.width.

Works on IE and other browsers as far as I know (I have only tested it on IE11).

Super clean and, if I am not mistaken, efficient.

What is the difference between require_relative and require in Ruby?

Just look at the docs:

require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement.

For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case:

require_relative "data/customer_data_1"

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

Bash sets the shell variable OSTYPE. From man bash:

Automatically set to a string that describes the operating system on which bash is executing.

This has a tiny advantage over uname in that it doesn't require launching a new process, so will be quicker to execute.

However, I'm unable to find an authoritative list of expected values. For me on Ubuntu 14.04 it is set to 'linux-gnu'. I've scraped the web for some other values. Hence:

case "$OSTYPE" in
  linux*)   echo "Linux / WSL" ;;
  darwin*)  echo "Mac OS" ;; 
  win*)     echo "Windows" ;;
  msys*)    echo "MSYS / MinGW / Git Bash" ;;
  cygwin*)  echo "Cygwin" ;;
  bsd*)     echo "BSD" ;;
  solaris*) echo "Solaris" ;;
  *)        echo "unknown: $OSTYPE" ;;

The asterisks are important in some instances - for example OSX appends an OS version number after the 'darwin'. The 'win' value is actually 'win32', I'm told - maybe there is a 'win64'?

Perhaps we could work together to populate a table of verified values here:

  • Linux Ubuntu (incl. WSL): linux-gnu
  • Cygwin 64-bit: cygwin
  • Msys/MINGW (Git Bash for Windows): msys

(Please append your value if it differs from existing entries)

LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

I had this problem minutes ago. It went away when I added 'extern "C"' to the main() definition.

Oddly, another simple program I wrote yesterday is almost identical, does not have the extern "C", yet compiled without this linker error.

This makes me think the problem is some subtle setting to be found deep in some configuration dialog, and that 'extern "C"' doesn't really solve the underlying problem, but superficially makes things work.

Android "hello world" pushnotification example

Overview of gcm: You send a request to google server from your android phone. You receive a registration id as a response. You will then have to send this registration id to the server from where you wish to send notifications to the mobile. Using this registration id you can then send notification to the device.


  1. To send a notification you send the data(message) with the registration id of the device to (use curl in php).
  2. To receive notification and registration etc, thats all you will be requiring.
  3. You will have to store the registration id on the device as well as on server. If you use GCM.jar the registration id is stored in preferences. If you wish you can save it in your local database as well.

How to make an element width: 100% minus padding?

Here is the recommendation from, which has good solution examples:

Instead of setting the width of the div to 100%, set it to auto, and be sure, that the <div> is set to display: block (default for <div>).

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

This is the better solution:

verify(mock_contractsDao, times(1)).save(Mockito.eq("Parameter I'm expecting"));

PHP Fatal error: Cannot redeclare class

Sometimes that happens due to some bugs in PHP's FastCGI.

Try to restart it. At Ubuntu it's:

service php-fastcgi restart

Simple state machine example in C#?

You can use my solution, this is the most convenient way. It’s also free.

Create state machine in three steps :

1. Create scheme in node editor and load it in your project using library

StateMachine stateMachine = new StateMachine("scheme.xml");

2. Describe your app logic on events?


3. Run the state machine



Node editor:


Use jQuery to change value of a label

Validation (HTML5): Attribute 'name' is not a valid attribute of element 'label'.

"unrecognized import path" with go get

The issues are relating to an invalid GOROOT.

I think you installed Go in /usr/local/go.
So change your GOROOT path to the value of /usr/local/go/bin.

It seems that you meant to have your workspace (GOPATH) located at /home/me/go.

This might fix your problem.
Add this to the bottom of your bash profile, located here => $HOME/.profile

export GOROOT=/usr/local/go
export GOPATH=$HOME/go
export PATH=$PATH:$GOROOT/bin

Make sure to remove the old references of GOROOT.

Then try installing web.go again.

If that doesn't work, then have Ubuntu install Go for you.

sudo apt-get install golang

Video tutorial:

PHP - check if variable is undefined

    $isTouch = $variable;


    $isTouch = "";// 

How to update json file with python

def updateJsonFile():
    jsonFile = open("replayScript.json", "r") # Open the JSON file for reading
    data = json.load(jsonFile) # Read the JSON into the buffer
    jsonFile.close() # Close the JSON file

    ## Working with buffered content
    tmp = data["location"] 
    data["location"] = path
    data["mode"] = "replay"

    ## Save our changes to JSON file
    jsonFile = open("replayScript.json", "w+")

Why does the C++ STL not provide any "tree" containers?

There are two reasons you could want to use a tree:

You want to mirror the problem using a tree-like structure:
For this we have boost graph library

Or you want a container that has tree like access characteristics For this we have

Basically the characteristics of these two containers is such that they practically have to be implemented using trees (though this is not actually a requirement).

See also this question: C tree Implementation

Change keystore password from no password to a non blank password

Add -storepass to keytool arguments.

keytool -storepasswd -storepass '' -keystore mykeystore.jks

But also notice that -list command does not always require a password. I could execute follow command in both cases: without password or with valid password

$JAVA_HOME/bin/keytool -list -keystore $JAVA_HOME/jre/lib/security/cacerts

How to extract .war files in java? ZIP vs JAR

If you using Linux or Ubuntu than you can directly extract data from .war file.

A war file is just a jar file, to extract it, just issue following command using the jar program:

jar -xvf yourWARfileName.war

Java Generics With a Class & an Interface - Together

Actually, you can do what you want. If you want to provide multiple interfaces or a class plus interfaces, you have to have your wildcard look something like this:

<T extends ClassA & InterfaceB>

See the Generics Tutorial at, specifically the Bounded Type Parameters section, at the bottom of the page. You can actually list more than one interface if you wish, using & InterfaceName for each one that you need.

This can get arbitrarily complicated. To demonstrate, see the JavaDoc declaration of Collections#max, which (wrapped onto two lines) is:

public static <T extends Object & Comparable<? super T>> T
                                           max(Collection<? extends T> coll)

why so complicated? As said in the Java Generics FAQ: To preserve binary compatibility.

It looks like this doesn't work for variable declaration, but it does work when putting a generic boundary on a class. Thus, to do what you want, you may have to jump through a few hoops. But you can do it. You can do something like this, putting a generic boundary on your class and then:

class classB { }
interface interfaceC { }

public class MyClass<T extends classB & interfaceC> {
    Class<T> variable;

to get variable that has the restriction that you want. For more information and examples, check out page 3 of Generics in Java 5.0. Note, in <T extends B & C>, the class name must come first, and interfaces follow. And of course you can only list a single class.

Difference between agile and iterative and incremental development

Agile is mostly used technique in project development.In agile technology peoples are switches from one technology to other ..Main purpose is to remove dependancy. Like Peoples shifted from production to development,and development to testing. Thats why dependancy will remove on a single team or person..

How do I copy the contents of one ArrayList into another?

There are no implicit copies made in java via the assignment operator. Variables contain a reference value (pointer) and when you use = you're only coping that value.

In order to preserve the contents of myTempObject you would need to make a copy of it.

This can be done by creating a new ArrayList using the constructor that takes another ArrayList:

ArrayList<Object> myObject = new ArrayList<Object>(myTempObject);

Edit: As Bohemian points out in the comments below, is this what you're asking? By doing the above, both ArrayLists (myTempObject and myObject) would contain references to the same objects. If you actually want a new list that contains new copies of the objects contained in myTempObject then you would need to make a copy of each individual object in the original ArrayList

How to connect to SQL Server database from JavaScript in the browser?

You shouldn´t use client javascript to access databases for several reasons (bad practice, security issues, etc) but if you really want to do this, here is an example:

var connection = new ActiveXObject("ADODB.Connection") ;

var connectionstring="Data Source=<server>;Initial Catalog=<catalog>;User ID=<user>;Password=<password>;Provider=SQLOLEDB";

var rs = new ActiveXObject("ADODB.Recordset");

rs.Open("SELECT * FROM table", connection);


A better way to connect to a sql server would be to use some server side language like PHP, Java, .NET, among others. Client javascript should be used only for the interfaces.

And there are rumors of an ancient legend about the existence of server javascript, but this is another story. ;)

How can I check if a value is of type Integer?

Here is the function for to check is String is Integer or not ?

public static boolean isStringInteger(String number ){
    }catch(Exception e ){
        return false;
    return true;

How to store decimal values in SQL Server?

The settings for Decimal are its precision and scale or in normal language, how many digits can a number have and how many digits do you want to have to the right of the decimal point.

So if you put PI into a Decimal(18,0) it will be recorded as 3?

If you put PI into a Decimal(18,2) it will be recorded as 3.14?

If you put PI into Decimal(18,10) be recorded as 3.1415926535.

Cannot call getSupportFragmentManager() from activity

Simply Use

 FragmentManager fm = getActivity().getSupportFragmentManager();

Remember always when accessing fragment inflating in MainLayout use Casting or getActivity().

How can I set the Secure flag on an ASP.NET Session Cookie?

secure - This attribute tells the browser to only send the cookie if the request is being sent over a secure channel such as HTTPS. This will help protect the cookie from being passed over unencrypted requests. If the application can be accessed over both HTTP and HTTPS, then there is the potential that the cookie can be sent in clear text.

CSS get height of screen resolution

Use height and width in percentage.

For example:

width: 80%;
height: 80%;

How to fill a datatable with List<T>

I also had to come up with an alternate solution, as none of the options listed here worked in my case. I was using an IEnumerable and the underlying data was a IEnumerable and the properties couldn't be enumerated. This did the trick:

// remove "this" if not on C# 3.0 / .NET 3.5
public static DataTable ConvertToDataTable<T>(this IEnumerable<T> data)
    List<IDataRecord> list = data.Cast<IDataRecord>().ToList();

    PropertyDescriptorCollection props = null;
    DataTable table = new DataTable();
    if (list != null && list.Count > 0)
        props = TypeDescriptor.GetProperties(list[0]);
        for (int i = 0; i < props.Count; i++)
            PropertyDescriptor prop = props[i];
            table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
    if (props != null)
        object[] values = new object[props.Count];
        foreach (T item in data)
            for (int i = 0; i < values.Length; i++)
                values[i] = props[i].GetValue(item) ?? DBNull.Value;
    return table;

How do I enable C++11 in gcc?

As previously mentioned - in case of a project, Makefile or otherwise, this is a project configuration issue, where you'll likely need to specify other flags too.

But what about one-off programs, where you would normally just write g++ file.cpp && ./a.out?

Well, I would much like to have some #pragma to turn in on at source level, or maybe a default extension - say .cxx or .C11 or whatever, trigger it by default. But as of today, there is no such feature.

But, as you probably are working in a manual environment (i.e. shell), you can just have an alias in you .bashrc (or whatever):

alias g++11="g++ -std=c++0x"

or, for newer G++ (and when you want to feel "real C++11")

alias g++11="g++ -std=c++11"

You can even alias to g++ itself, if you hate C++03 that much ;)

What's the simplest way to list conflicted files in Git?

git diff --check

will show the list of files containing conflict markers including line numbers.

For example:

> git diff --check
index-localhost.html:85: leftover conflict marker
index-localhost.html:87: leftover conflict marker
index-localhost.html:89: leftover conflict marker
index.html:85: leftover conflict marker
index.html:87: leftover conflict marker
index.html:89: leftover conflict marker

source :

Error: No toolchains found in the NDK toolchains folder for ABI with prefix: llvm

For Android studio 3.2.1+

Upgrade your Gradle Plugin

classpath ''

If you are now getting this error:

Could not find

just add google() to your repositories, like this:

repositories {

Happy Coding -:)

Remove last item from array

// Setup
var myArray = [["John", 23], ["cat", 2]];

// Only change code below this line
var removedFromMyArray;
removedFromMyArray = myArray.pop()

How do I replace whitespaces with underscore?

use string's replace method:

"this should be connected".replace(" ", "_")

"this_should_be_disconnected".replace("_", " ")

Convert List to Pandas Dataframe Column


L = ['Thanks You', 'Its fine no problem', 'Are you sure']

#create new df 
df = pd.DataFrame({'col':L})
print (df)

0           Thanks You
1  Its fine no problem
2         Are you sure

df = pd.DataFrame({'oldcol':[1,2,3]})

#add column to existing df 
df['col'] = L
print (df)
   oldcol                  col
0       1           Thanks You
1       2  Its fine no problem
2       3         Are you sure

Thank you DYZ:

#default column name 0
df = pd.DataFrame(L)
print (df)
0           Thanks You
1  Its fine no problem
2         Are you sure

'dict' object has no attribute 'has_key'

In python3, has_key(key) is replaced by __contains__(key)

Tested in python3.7:

a = {'a':1, 'b':2, 'c':3}

EOFError: end of file reached issue with Net::HTTP

I find that I run into Net::HTTP and Net::FTP problems like this periodically, and when I do, surrounding the call with a timeout() makes all of those issues vanish. So where this will occasionally hang for 3 minutes or so and then raise an EOFError:

res = Net::HTTP.post_form(uri, args)

This always fixes it for me:

res = timeout(120) { Net::HTTP.post_form(uri, args) }

How do you dynamically allocate a matrix?

Using the double-pointer is by far the best compromise between execution speed/optimisation and legibility. Using a single array to store matrix' contents is actually what a double-pointer does.

I have successfully used the following templated creator function (yes, I know I use old C-style pointer referencing, but it does make code more clear on the calling side with regards to changing parameters - something I like about pointers which is not possible with references. You will see what I mean):

/// Matrix Allocator Utility
/// @param pppArray Pointer to the double-pointer where the matrix should be allocated.
/// @param iRows Number of rows.
/// @param iColumns Number of columns.
/// @return Successful allocation returns true, else false.
template <typename T>
bool NewMatrix(T*** pppArray, 
               size_t iRows, 
               size_t iColumns)
   bool l_bResult = false;
   if (pppArray != 0) // Test if pointer holds a valid address.
   {                  // I prefer using the shorter 0 in stead of NULL.
      if (!((*pppArray) != 0)) // Test if the first element is currently unassigned.
      {                        // The "double-not" evaluates a little quicker in general.
         // Allocate and assign pointer array.
         (*pppArray) = new T* [iRows]; 
         if ((*pppArray) != 0) // Test if pointer-array allocation was successful.
            // Allocate and assign common data storage array.
            (*pppArray)[0] = new T [iRows * iColumns]; 
            if ((*pppArray)[0] != 0) // Test if data array allocation was successful.
               // Using pointer arithmetic requires the least overhead. There is no 
               // expensive repeated multiplication involved and very little additional 
               // memory is used for temporary variables.
               T** l_ppRow = (*pppArray);
               T* l_pRowFirstElement = l_ppRow[0];
               for (size_t l_iRow = 1; l_iRow < iRows; l_iRow++)
                  l_pRowFirstElement += iColumns;
                  l_ppRow[0] = l_pRowFirstElement;
               l_bResult = true;

To de-allocate the memory created using the abovementioned utility, one simply has to de-allocate in reverse.

/// Matrix De-Allocator Utility
/// @param pppArray Pointer to the double-pointer where the matrix should be de-allocated.
/// @return Successful de-allocation returns true, else false.
template <typename T>
bool DeleteMatrix(T*** pppArray)
   bool l_bResult = false;
   if (pppArray != 0) // Test if pointer holds a valid address.
      if ((*pppArray) != 0) // Test if pointer array was assigned.
         if ((*pppArray)[0] != 0) // Test if data array was assigned.
               // De-allocate common storage array.
               delete [] (*pppArray)[0];
         // De-allocate pointer array.
         delete [] (*pppArray);
         (*pppArray) = 0;
         l_bResult = true;

To use these abovementioned template functions is then very easy (e.g.):

   double l_ppMatrix = 0;
   NewMatrix(&l_ppMatrix, 3, 3); // Create a 3 x 3 Matrix and store it in l_ppMatrix.

How to reload .bash_profile from the command line?

I am running Sierra, and was working on this for a while (trying all recommended solutions). I became confounded so eventually tried restarting my computer! It worked

my conclusion is that sometimes a hard reset is necessary

Why does LayoutInflater ignore the layout_width and layout_height layout parameters I've specified?

wanna add to main answer above
I tried to follow it but my recyclerView began to stretch every item to a screen
I had to add next line after inflating for reach to goal

itemLayoutView.setLayoutParams(new RecyclerView.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, RecyclerView.LayoutParams.WRAP_CONTENT));

I already added these params by xml but it didnot work correctly
and with this line all is ok

How to add native library to "java.library.path" with Eclipse launch (instead of overriding it)

Many of the existing answers assume you want to set this for a particular project, but I needed to set it for Eclipse itself in order to support integrated authentication for the SQL Server JDBC driver.

To do this, I followed these instructions for launching Eclipse from the Java commandline instead of its normal launcher. Then I just modified that script to add my -Djava.library.path argument to the Java commandline.

How to save a PNG image server-side, from a base64 data string

It's simple :

Let's imagine that you are trying to upload a file within js framework, ajax request or mobile application (Client side)

  1. Firstly you send a data attribute that contains a base64 encoded string.
  2. In the server side you have to decode it and save it in a local project folder.

Here how to do it using PHP


$base64String = "kfezyufgzefhzefjizjfzfzefzefhuze"; // I put a static base64 string, you can implement you special code to retrieve the data received via the request.

$filePath = "/MyProject/public/uploads/img/test.png";

file_put_contents($filePath, base64_decode($base64String));


laravel compact() and ->with()

Laravel Framework 5.6.26

return more than one array then we use compact('array1', 'array2', 'array3', ...) to return view.

viewblade is the frontend (view) blade.

return view('viewblade', compact('view1','view2','view3','view4'));

PHP mySQL - Insert new record into table with auto-increment on primary key

This is phpMyAdmin method.

$query = "INSERT INTO myTable
         (mtb_i_idautoinc, mtb_s_string1, mtb_s_string2) 
         (NULL, 'Jagodina', '35000')";

How to implement an STL-style iterator and avoid common pitfalls? has a handy chart that details the specs of § 24.2.2 of the C++11 standard. Basically, the iterators have tags that describe the valid operations, and the tags have a hierarchy. Below is purely symbolic, these classes don't actually exist as such.

iterator {
    iterator(const iterator&);
    iterator& operator=(const iterator&);
    iterator& operator++(); //prefix increment
    reference operator*() const;
    friend void swap(iterator& lhs, iterator& rhs); //C++11 I think

input_iterator : public virtual iterator {
    iterator operator++(int); //postfix increment
    value_type operator*() const;
    pointer operator->() const;
    friend bool operator==(const iterator&, const iterator&);
    friend bool operator!=(const iterator&, const iterator&); 
//once an input iterator has been dereferenced, it is 
//undefined to dereference one before that.

output_iterator : public virtual iterator {
    reference operator*() const;
    iterator operator++(int); //postfix increment
//dereferences may only be on the left side of an assignment
//once an output iterator has been dereferenced, it is 
//undefined to dereference one before that.

forward_iterator : input_iterator, output_iterator {
//multiple passes allowed

bidirectional_iterator : forward_iterator {
    iterator& operator--(); //prefix decrement
    iterator operator--(int); //postfix decrement

random_access_iterator : bidirectional_iterator {
    friend bool operator<(const iterator&, const iterator&);
    friend bool operator>(const iterator&, const iterator&);
    friend bool operator<=(const iterator&, const iterator&);
    friend bool operator>=(const iterator&, const iterator&);

    iterator& operator+=(size_type);
    friend iterator operator+(const iterator&, size_type);
    friend iterator operator+(size_type, const iterator&);
    iterator& operator-=(size_type);  
    friend iterator operator-(const iterator&, size_type);
    friend difference_type operator-(iterator, iterator);

    reference operator[](size_type) const;

contiguous_iterator : random_access_iterator { //C++17
}; //elements are stored contiguously in memory.

You can either specialize std::iterator_traits<youriterator>, or put the same typedefs in the iterator itself, or inherit from std::iterator (which has these typedefs). I prefer the second option, to avoid changing things in the std namespace, and for readability, but most people inherit from std::iterator.

struct std::iterator_traits<youriterator> {        
    typedef ???? difference_type; //almost always ptrdiff_t
    typedef ???? value_type; //almost always T
    typedef ???? reference; //almost always T& or const T&
    typedef ???? pointer; //almost always T* or const T*
    typedef ???? iterator_category;  //usually std::forward_iterator_tag or similar

Note the iterator_category should be one of std::input_iterator_tag, std::output_iterator_tag, std::forward_iterator_tag, std::bidirectional_iterator_tag, or std::random_access_iterator_tag, depending on which requirements your iterator satisfies. Depending on your iterator, you may choose to specialize std::next, std::prev, std::advance, and std::distance as well, but this is rarely needed. In extremely rare cases you may wish to specialize std::begin and std::end.

Your container should probably also have a const_iterator, which is a (possibly mutable) iterator to constant data that is similar to your iterator except it should be implicitly constructable from a iterator and users should be unable to modify the data. It is common for its internal pointer to be a pointer to non-constant data, and have iterator inherit from const_iterator so as to minimize code duplication.

My post at Writing your own STL Container has a more complete container/iterator prototype.

How to store .pdf files into MySQL as BLOBs using PHP?

//Pour inserer :
            $pdf = addslashes(file_get_contents($_FILES['inputname']['tmp_name']));
            $filetype = addslashes($_FILES['inputname']['type']);//pour le test 
            $namepdf = addslashes($_FILES['inputname']['name']);            
            if (substr($filetype, 0, 11) == 'application'){
            $mysqli->query("insert into tablepdf(pdf_nom,pdf)value('$namepdf','$pdf')");
//Pour afficher :
            $row = $mysqli->query("SELECT * FROM tablepdf where id=(select max(id) from tablepdf)");
            foreach($row as $result){
            header('Content-type: application/pdf');
            echo file_get_contents('data:application/pdf;base64,'.base64_encode($file));

How do I find which program is using port 80 in Windows?

Type in the command:

netstat -aon | findstr :80

It will show you all processes that use port 80. Notice the pid (process id) in the right column.

If you would like to free the port, go to Task Manager, sort by pid and close those processes.

-a displays all connections and listening ports.

-o displays the owning process ID associated with each connection.

-n displays addresses and port numbers in numerical form.

How do I get the time of day in javascript/Node.js?

Both prior answers are definitely good solutions. If you're amenable to a library, I like moment.js - it does a lot more than just getting/formatting the date.

Can an XSLT insert the current date?

Late answer, but my solution works in Eclipse XSLT. Eclipse uses XSLT 1 at time of this writing. You can install an XSLT 2 engine like Saxon. Or you can use the XSLT 1 solution below to insert current date and time.

<xsl:value-of select=""/>

This will call Java's Data class to output the date. It will not work unless you also put the following "java:" definition in your <xsl:stylesheet> tag.

<xsl:stylesheet [...snip...]

I hope that helps someone. This simple answer was difficult to find for me.

How do I list all remote branches in Git 1.7+?

Git Branching - Remote Branches

git ls-remote

Git documentation.

Converting 24 hour time to 12 hour time w/ AM & PM using Javascript

This way you have more control over the output - i.e - if you wanted the time format to be '4:30 pm' instead of '04:30 P.M.' - you can convert to whatever format you decide you want - and change it later too. Instead of being constrained to some old method that does not allow any flexibility.

and you only need to convert the first 2 digits as the minute and seconds digits are the same in 24 hour time or 12 hour time.

var my_time_conversion_arr = {'01':"01", '02':"02", '03':"03", '04':"04", '05':"05", '06':"06", '07':"07", '08':"08", '09':"09", '10':"10", '11':"11", '12': "12", '13': "1", '14': "2", '15': "3", '16': "4", '17': "5", '18': "6", '19': "7", '20': "8", '21': "9", '22': "10", '23': "11", '00':"12"};

                var AM_or_PM = "";
                var twenty_four_hour_time = "16:30";
                var twenty_four_hour_time_arr = twenty_four_hour_time.split(":");
                var twenty_four_hour_time_first_two_digits = twenty_four_hour_time_arr[0];

                var first_two_twelve_hour_digits_converted = my_time_conversion_arr[twenty_four_hour_time_first_two_digits];

                var time_strng_to_nmbr = parseInt(twenty_four_hour_time_first_two_digits);
                if(time_strng_to_nmbr >12){
                    //alert("GREATER THAN 12");
                    AM_or_PM = "pm";
                    AM_or_PM = "am";

                var twelve_hour_time_conversion = first_two_twelve_hour_digits_converted+":"+twenty_four_hour_time_arr[1]+" "+AM_or_PM;

failed to open stream: No such file or directory in

It's because you have included a leading / in your file path. The / makes it start at the top of your filesystem. Note: filesystem path, not Web site path (you're not accessing it over HTTP). You can use a relative path with include_once (one that doesn't start with a leading /).

You can change it to this:

include_once 'headerSite.php';

That will look first in the same directory as the file that's including it (i.e. C:\xampp\htdocs\PoliticalForum\ in your example.

Flutter - The method was called on null

The reason for this error occurs is that you are using the CryptoListPresenter _presenter without initializing.

I found that CryptoListPresenter _presenter would have to be initialized to fix because _presenter.loadCurrencies() is passing through a null variable at the time of instantiation;

there are two ways to initialize

  1. Can be initialized during an declaration, like this

    CryptoListPresenter _presenter = CryptoListPresenter();
  2. In the second, initializing(with assigning some value) it when initState is called, which the framework will call this method once for each state object.

    void initState() {
      _presenter = CryptoListPresenter(...);

How to "crop" a rectangular image into a square with CSS?

Assuming they do not have to be in IMG tags...


<div class="thumb1">


.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;

.thumb1:hover { YOUR HOVER STYLES HERE }

EDIT: If the div needs to link somewhere just adjust HTML and Styles like so:


<div class="thumb1">
<a href="#">Link</a>


.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;

.thumb1 a {
  display: block;
  width: 250px;
  height: 250px;

.thumb1 a:hover { YOUR HOVER STYLES HERE }

Note this could also be modified to be responsive, for example % widths and heights etc.

How to get input text length and validate user in javascript

JavaScript validation is not secure as anybody can change what your script does in the browser. Using it for enhancing the visual experience is ok though.

var textBox = document.getElementById("myTextBox");
var textLength = textBox.value.length;
if(textLength > 5)
    //red = "#FF0000";
    //green = "#00FF00";

Uploading Images to Server android

Try this method for uploading Image file from camera

package com.example.imageupload;


import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.message.BasicHeader;

public class MultipartEntity implements HttpEntity {

private String boundary = null;

ByteArrayOutputStream out = new ByteArrayOutputStream();
boolean isSetLast = false;
boolean isSetFirst = false;

public MultipartEntity() {
    this.boundary = System.currentTimeMillis() + "";

public void writeFirstBoundaryIfNeeds() {
    if (!isSetFirst) {
        try {
            out.write(("--" + boundary + "\r\n").getBytes());
        } catch (final IOException e) {

    isSetFirst = true;

public void writeLastBoundaryIfNeeds() {
    if (isSetLast) {
    try {
        out.write(("\r\n--" + boundary + "--\r\n").getBytes());
    } catch (final IOException e) {

    isSetLast = true;

public void addPart(final String key, final String value) {
    try {
        out.write(("Content-Disposition: form-data; name=\"" + key + "\"\r\n")
        out.write("Content-Type: text/plain; charset=UTF-8\r\n".getBytes());
        out.write("Content-Transfer-Encoding: 8bit\r\n\r\n".getBytes());
        out.write(("\r\n--" + boundary + "\r\n").getBytes());
    } catch (final IOException e) {


public void addPart(final String key, final String fileName,
        final InputStream fin) {
    addPart(key, fileName, fin, "application/octet-stream");

public void addPart(final String key, final String fileName,
        final InputStream fin, String type) {
    try {
        type = "Content-Type: " + type + "\r\n";
        out.write(("Content-Disposition: form-data; name=\"" + key
                + "\"; filename=\"" + fileName + "\"\r\n").getBytes());
        out.write("Content-Transfer-Encoding: binary\r\n\r\n".getBytes());

        final byte[] tmp = new byte[4096];
        int l = 0;
        while ((l = != -1) {
            out.write(tmp, 0, l);
    } catch (final IOException e) {

    } finally {
        try {
        } catch (final IOException e) {


public void addPart(final String key, final File value) {
    try {
        addPart(key, value.getName(), new FileInputStream(value));
    } catch (final FileNotFoundException e) {


public long getContentLength() {
    return out.toByteArray().length;

public Header getContentType() {
    return new BasicHeader("Content-Type", "multipart/form-data; boundary="
            + boundary);

public boolean isChunked() {
    return false;

public boolean isRepeatable() {
    return false;

public boolean isStreaming() {
    return false;

public void writeTo(final OutputStream outstream) throws IOException {

public Header getContentEncoding() {
    return null;

public void consumeContent() throws IOException,
        UnsupportedOperationException {
    if (isStreaming()) {
        throw new UnsupportedOperationException(
                "Streaming entity does not implement #consumeContent()");

public InputStream getContent() throws IOException,
        UnsupportedOperationException {
    return new ByteArrayInputStream(out.toByteArray());


Use of class for uploading

private void doFileUpload(File file_path) {

    Log.d("Uri", "Do file path" + file_path);

    try {

        HttpClient client = new DefaultHttpClient();
        //use your server path of php file
        HttpPost post = new HttpPost(ServerUploadPath);

        Log.d("ServerPath", "Path" + ServerUploadPath);

        FileBody bin1 = new FileBody(file_path);
        Log.d("Enter", "Filebody complete " + bin1);

        MultipartEntity reqEntity = new MultipartEntity();
        reqEntity.addPart("uploaded_file", bin1);
        reqEntity.addPart("email", new StringBody(useremail));

        Log.d("Enter", "Image send complete");

        HttpResponse response = client.execute(post);
        resEntity = response.getEntity();
        Log.d("Enter", "Get Response");
        try {

            final String response_str = EntityUtils.toString(resEntity);
            if (resEntity != null) {
                Log.i("RESPONSE", response_str);
                JSONObject jobj = new JSONObject(response_str);
                result = jobj.getString("ResponseCode");
                Log.e("Result", "...." + result);

        } catch (Exception ex) {
            Log.e("Debug", "error: " + ex.getMessage(), ex);
    } catch (Exception e) {
        Log.e("Upload Exception", "");

Service for uploading

$image_name = $_FILES["uploaded_file"]["name"]; 
$tmp_arr = explode(".",$image_name);
$img_extn = end($tmp_arr);
$new_image_name = 'image_'. uniqid() .'.'.$img_extn;    

if (file_exists("Images/".$new_image_name))
           $msg=$new_image_name . " already exists."
           header('Content-type: application/json');        
           echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=>$msg));        
move_uploaded_file($_FILES["uploaded_file"]["tmp_name"],"Images/". $new_image_name);
                   $flag = 1;

if($flag == 1){                    
            require 'db.php';   
            $static_url =$new_image_name;
            $conn=mysql_connect($db_host,$db_username,$db_password) or die("unable to connect localhost".mysql_error());
            $db=mysql_select_db($db_database,$conn) or die("unable to select message_app"); 
            $email = "";
                     $email = $_REQUEST['email'];

    $sql ="insert into alert(images) values('$static_url')";


    echo json_encode(array("ResponseCode"=>"1","ResponseMsg"=> "Insert data successfully.","Result"=>"True","ImageName"=>$static_url,"email"=>$email));
       } else

         echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=> "Could not insert data.","Result"=>"False","email"=>$email));
    echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=> "Erroe While Inserting Image.","Result"=>"False"));

how to add key value pair in the JSON object already declared

You can add more key value pair in the same object without replacing old ones in following way:

var obj = {};

obj = {
"1": "aa",
"2": "bb"

obj["3"] = "cc";

Below is the code and jsfiddle link to sample demo that will add more key value pairs to the already existed obj on clicking of button:

var obj = {
    "1": "aa",
    "2": "bb"

var noOfItems = Object.keys(obj).length;

$('#btnAddProperty').on('click', function() {
    obj[noOfItems] = $.trim($('#txtName').val());

pyplot axes labels for subplots

Wen-wei Liao's answer is good if you are not trying to export vector graphics or that you have set up your matplotlib backends to ignore colorless axes; otherwise the hidden axes would show up in the exported graphic.

My answer suplabel here is similar to the fig.suptitle which uses the fig.text function. Therefore there is no axes artist being created and made colorless. However, if you try to call it multiple times you will get text added on top of each other (as fig.suptitle does too). Wen-wei Liao's answer doesn't, because fig.add_subplot(111) will return the same Axes object if it is already created.

My function can also be called after the plots have been created.

def suplabel(axis,label,label_prop=None,
    ''' Add super ylabel or xlabel to the figure
    Similar to matplotlib.suptitle
    axis       - string: "x" or "y"
    label      - string
    label_prop - keyword dictionary for Text
    labelpad   - padding from the axis (default: 5)
    ha         - horizontal alignment (default: "center")
    va         - vertical alignment (default: "center")
    fig = pylab.gcf()
    xmin = []
    ymin = []
    for ax in fig.axes:
    xmin,ymin = min(xmin),min(ymin)
    dpi = fig.dpi
    if axis.lower() == "y":
        x = xmin-float(labelpad)/dpi
        y = 0.5
    elif axis.lower() == 'x':
        rotation = 0.
        x = 0.5
        y = ymin - float(labelpad)/dpi
        raise Exception("Unexpected axis: x or y")
    if label_prop is None: 
        label_prop = dict()

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

You have to add following in header:

<script type="text/javascript">
        function fixform() {
            if (opener.document.getElementById("aspnetForm").target != "_blank") return;

            opener.document.getElementById("aspnetForm").target = "";
            opener.document.getElementById("aspnetForm").action = opener.location.href;

Then call fixform() in load your page.

How to get the response of XMLHttpRequest?

In XMLHttpRequest, using XMLHttpRequest.responseText may raise the exception like below

 Failed to read the \'responseText\' property from \'XMLHttpRequest\': 
 The value is only accessible if the object\'s \'responseType\' is \'\' 
 or \'text\' (was \'arraybuffer\')

Best way to access the response from XHR as follows

function readBody(xhr) {
    var data;
    if (!xhr.responseType || xhr.responseType === "text") {
        data = xhr.responseText;
    } else if (xhr.responseType === "document") {
        data = xhr.responseXML;
    } else {
        data = xhr.response;
    return data;

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
    if (xhr.readyState == 4) {
}'GET', '', true);

CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default

If above all options are not working and you have used nuget packages like Microsoft.Net.Compilers and CodeDom and still not working then there is issue with your project file open project file. Project file is using one of the compiler option which not support your selected language. Open project file with notepad++ and remove the following line.

Orignal Project File

<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="">
  <Import Project="..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props" Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props')" />
  <!--Don't delete below one-->
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />

Remove The following lines

  <Import Project="..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props" Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props')" />

Select DataFrame rows between two dates

Inspired by unutbu

print(df.dtypes)                                 #Make sure the format is 'object'. Rerunning this after index will not show values.
columnName = 'YourColumnName'
df[columnName+'index'] = df[columnName]          #Create a new column for index
df.set_index(columnName+'index', inplace=True)   #To build index on the timestamp/dates
df.loc['2020-09-03 01:00':'2020-09-06']          #Select range from the index. This is your new Dataframe.

Make element fixed on scroll

You want to use jQuery WayPoints. It is a very simple plugin and acheives exactly what you have described.

Most straightforward implementation

    $('.thing').waypoint(function(direction) {
  alert('Top of thing hit top of viewport.');

You will need to set some custom CSS to set exactly where it does become stuck, this is normal though for most ways to do it.

This page will show you all the examples and info that you need.

For future reference a example of it stopping and starting is this website. It is a "in the wild" example.

Is it possible to import modules from all files in a directory, using a wildcard?

If you are using webpack. This imports files automatically and exports as api namespace.

So no need to update on every file addition.

import camelCase from "lodash-es";
const requireModule = require.context("./", false, /\.js$/); // 
const api = {};

requireModule.keys().forEach(fileName => {
  if (fileName === "./index.js") return;
  const moduleName = camelCase(fileName.replace(/(\.\/|\.js)/g, ""));
  api[moduleName] = {

export default api;

For Typescript users;

import { camelCase } from "lodash-es"
const requireModule = require.context("./folderName", false, /\.ts$/)

interface LooseObject {
  [key: string]: any

const api: LooseObject = {}

requireModule.keys().forEach(fileName => {
  if (fileName === "./index.ts") return
  const moduleName = camelCase(fileName.replace(/(\.\/|\.ts)/g, ""))
  api[moduleName] = {

export default api

jQuery hide and show toggle div with plus and minus icon


<div class="Settings" id="GTSettings">
  <h3 class="SettingsTitle"><a class="toggle" ><img src="${appThemePath}/images/toggle-collapse-light.gif" alt="" /></a>General Theme Settings</h3>
  <div class="options">
          <h4>Back-Ground Color</h4>
          <input type="text" id="body-backGroundColor" class="themeselector" readonly="readonly">
          <h4>Text Color</h4>
          <input type="text" id="body-fontColor" class="themeselector" readonly="readonly">

<div class="Settings" id="GTSettings">
  <h3 class="SettingsTitle"><a class="toggle" ><img src="${appThemePath}/images/toggle-collapse-light.gif" alt="" /></a>Content Theme Settings</h3>
  <div class="options">
          <h4>Back-Ground Color</h4>
          <input type="text" id="body-backGroundColor" class="themeselector" readonly="readonly">
          <h4>Text Color</h4>
          <input type="text" id="body-fontColor" class="themeselector" readonly="readonly">


$(document).ready(function() {

  $(".SettingsTitle").click(function(e) {
    var appThemePath = $("#appThemePath").text();

    var closeMenuImg = appThemePath + '/images/toggle-collapse-light.gif';
    var openMenuImg = appThemePath + '/images/toggle-collapse-dark.gif';

    var elem = $(this).next('.options');
    $('.SettingsTitle').not($(this)).parent().children("h3").children("a.toggle").children("img").attr('src', closeMenuImg);
    var targetImg = $(this).parent().children("h3").children("a.toggle").children("img").attr('src') === closeMenuImg ? openMenuImg : closeMenuImg;
    $(this).parent().children("h3").children("a.toggle").children("img").attr('src', targetImg);


How to get all enum values in Java?

YourEnumClass[] yourEnums = YourEnumClass.class.getEnumConstants();


YourEnumClass[] yourEnums = YourEnumClass.values();

Laravel stylesheets and javascript don't load for non-base routes

If you're using Laravel 3 and your CSS/JS files inside public folder like this


then you can call them using in Blade templates like this

{{ HTML::style('css/style.css'); }}
{{ HTML::script('js/jquery-1.8.2.min.js'); }}

Java HttpRequest JSON & Response Handling

The simplest way is using libraries like google-http-java-client but if you want parse the JSON response by yourself you can do that in a multiple ways, you can use org.json, json-simple, Gson, minimal-json, jackson-mapper-asl (from 1.x)... etc

A set of simple examples:

Using Gson:


import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

public class Gson {

    public static void main(String[] args) {

    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            HttpResponse result = httpClient.execute(request);
            String json = EntityUtils.toString(result.getEntity(), "UTF-8");

   gson = new;
            Response respuesta = gson.fromJson(json, Response.class);


        } catch (IOException ex) {
        return null;

    public class Response{

        private String example;
        private String fr;

        public String getExample() {
            return example;
        public void setExample(String example) {
            this.example = example;
        public String getFr() {
            return fr;
        public void setFr(String fr) {
   = fr;

Using json-simple:


import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

public class JsonSimple {

    public static void main(String[] args) {


    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            HttpResponse result = httpClient.execute(request);

            String json = EntityUtils.toString(result.getEntity(), "UTF-8");
            try {
                JSONParser parser = new JSONParser();
                Object resultObject = parser.parse(json);

                if (resultObject instanceof JSONArray) {
                    JSONArray array=(JSONArray)resultObject;
                    for (Object object : array) {
                        JSONObject obj =(JSONObject)object;

                }else if (resultObject instanceof JSONObject) {
                    JSONObject obj =(JSONObject)resultObject;

            } catch (Exception e) {
                // TODO: handle exception

        } catch (IOException ex) {
        return null;


Is there a way to add/remove several classes in one single instruction with classList?

The new spread operator makes it even easier to apply multiple CSS classes as array:

const list = ['first', 'second', 'third'];

Docker: How to use bash with an Alpine based docker image?

Alpine docker image doesn't have bash installed by default. You will need to add following commands to get bash:

RUN apk update && apk add bash

If youre using Alpine 3.3+ then you can just do

RUN apk add --no-cache bash

to keep docker image size small. (Thanks to comment from @sprkysnrky)

How to get different colored lines for different plots in a single figure?

Matplotlib does this by default.


import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)

Basic plot demonstrating color cycling

And, as you may already know, you can easily add a legend:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)

plt.legend(['y = x', 'y = 2x', 'y = 3x', 'y = 4x'], loc='upper left')

Basic plot with legend

If you want to control the colors that will be cycled through:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.gca().set_color_cycle(['red', 'green', 'blue', 'yellow'])

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)

plt.legend(['y = x', 'y = 2x', 'y = 3x', 'y = 4x'], loc='upper left')

Plot showing control over default color cycling

If you're unfamiliar with matplotlib, the tutorial is a good place to start.


First off, if you have a lot (>5) of things you want to plot on one figure, either:

  1. Put them on different plots (consider using a few subplots on one figure), or
  2. Use something other than color (i.e. marker styles or line thickness) to distinguish between them.

Otherwise, you're going to wind up with a very messy plot! Be nice to who ever is going to read whatever you're doing and don't try to cram 15 different things onto one figure!!

Beyond that, many people are colorblind to varying degrees, and distinguishing between numerous subtly different colors is difficult for more people than you may realize.

That having been said, if you really want to put 20 lines on one axis with 20 relatively distinct colors, here's one way to do it:

import matplotlib.pyplot as plt
import numpy as np

num_plots = 20

# Have a look at the colormaps here and decide which one you'd like:
colormap =
plt.gca().set_prop_cycle(plt.cycler('color',, 1, num_plots))))

# Plot several different functions...
x = np.arange(10)
labels = []
for i in range(1, num_plots + 1):
    plt.plot(x, i * x + 5 * i)
    labels.append(r'$y = %ix + %i$' % (i, 5*i))

# I'm basically just demonstrating several different legend options here...
plt.legend(labels, ncol=4, loc='upper center', 
           bbox_to_anchor=[0.5, 1.1], 
           columnspacing=1.0, labelspacing=0.0,
           handletextpad=0.0, handlelength=1.5,
           fancybox=True, shadow=True)

Unique colors for 20 lines based on a given colormap

CSS text-overflow: ellipsis; not working?

Can't comment due to reputation, so I'm making another answer:

In this case you will also have to remove the generally suggested display: block; property from the element you set the text-overflow: ellipsis; on, or it will cut off without the ... at the end.

"relocation R_X86_64_32S against " linking Error

Assuming you are generating a shared library, most probably what happens is that the variant of liblog4cplus.a you are using wasn't compiled with -fPIC. In linux, you can confirm this by extracting the object files from the static library and checking their relocations:

ar -x liblog4cplus.a  
readelf --relocs fileappender.o | egrep '(GOT|PLT|JU?MP_SLOT)'

If the output is empty, then the static library is not position-independent and cannot be used to generate a shared object.

Since the static library contains object code which was already compiled, providing the -fPIC flag won't help.

You need to get ahold of a version of liblog4cplus.a compiled with -fPIC and use that one instead.

How to delete a line from a text file in C#?

Read the file, remove the line in memory and put the contents back to the file (overwriting). If the file is large you might want to read it line for line, and creating a temp file, later replacing the original one.

How to throw RuntimeException ("cannot find symbol")

As everyone else has said, instantiate the object before throwing it.

Just wanted to add one bit; it's incredibly uncommon to throw a RuntimeException. It would be normal for code in the API to throw a subclass of this, but normally, application code would throw Exception, or something that extends Exception but not RuntimeException.

And in retrospect, I missed adding the reason why you use Exception instead of RuntimeException; @Jay, in the comment below, added in the useful bit. RuntimeException isn't a checked exception;

  • The method signature doesn't have to declare that a RuntimeException may be thrown.
  • Callers of that method aren't required to catch the exception, or acknowlege it in any way.
  • Developers who try to later use your code won't anticipate this problem unless they look carefully, and it will increase the maintenance burden of the code.

How to detect IE11?

Quite frankly I would say use a library that does what you need (like platform.js for example). At some point things will change and the library will be equipped for those changes and manual parsing using regular expressions will fail.

Thank god IE goes away...

Including non-Python files with

I just wanted to follow up on something I found working with Python 2.7 on Centos 6. Adding the package_data or data_files as mentioned above did not work for me. I added a MANIFEST.IN with the files I wanted which put the non-python files into the tarball, but did not install them on the target machine via RPM.

In the end, I was able to get the files into my solution using the "options" in the setup/setuptools. The option files let you modify various sections of the spec file from As follows.

from setuptools import setup

    author_email='[email protected]',
    options={'bdist_rpm': {'install_script': 'filewithinstallcommands'}},

file -

include license.txt

file - filewithinstallcommands:

mkdir -p $RPM_BUILD_ROOT/pathtoinstall/
#this line installs your python files
python install -O1 --root=$RPM_BUILD_ROOT --record=INSTALLED_FILES
#install license.txt into /pathtoinstall folder
install -m 700 license.txt $RPM_BUILD_ROOT/pathtoinstall/
echo /pathtoinstall/license.txt >> INSTALLED_FILES

is there a css hack for safari only NOT chrome?

There is a way to filter Safari 5+ from Chrome:

@media screen and (-webkit-min-device-pixel-ratio:0) { 
    /* Safari and Chrome */
    .myClass {

    /* Safari only override */
    ::i-block-chrome,.myClass {

How to abort makefile if variable not set?

TL;DR: Use the error function:

ifndef MY_FLAG
$(error MY_FLAG is not set)

Note that the lines must not be indented. More precisely, no tabs must precede these lines.

Generic solution

In case you're going to test many variables, it's worth defining an auxiliary function for that:

# Check that given variables are set and all have non-empty values,
# die with an error otherwise.
# Params:
#   1. Variable name(s) to test.
#   2. (optional) Error message to print.
check_defined = \
    $(strip $(foreach 1,$1, \
        $(call __check_defined,$1,$(strip $(value 2)))))
__check_defined = \
    $(if $(value $1),, \
      $(error Undefined $1$(if $2, ($2))))

And here is how to use it:

$(call check_defined, MY_FLAG)

$(call check_defined, OUT_DIR, build directory)
$(call check_defined, BIN_DIR, where to put binary artifacts)
$(call check_defined, \
            LIB_INCLUDE_DIR \
            LIB_SOURCE_DIR, \
        library path)

This would output an error like this:

Makefile:17: *** Undefined OUT_DIR (build directory).  Stop.


The real check is done here:

$(if $(value $1),,$(error ...))

This reflects the behavior of the ifndef conditional, so that a variable defined to an empty value is also considered "undefined". But this is only true for simple variables and explicitly empty recursive variables:

# ifndef and check_defined consider these UNDEFINED:
explicitly_empty =
simple_empty := $(explicitly_empty)

# ifndef and check_defined consider it OK (defined):
recursive_empty = $(explicitly_empty)

As suggested by @VictorSergienko in the comments, a slightly different behavior may be desired:

$(if $(value $1) tests if the value is non-empty. It's sometimes OK if the variable is defined with an empty value. I'd use $(if $(filter undefined,$(origin $1)) ...


Moreover, if it's a directory and it must exist when the check is run, I'd use $(if $(wildcard $1)). But would be another function.

Target-specific check

It is also possible to extend the solution so that one can require a variable only if a certain target is invoked.

$(call check_defined, ...) from inside the recipe

Just move the check into the recipe:

foo :
    @:$(call check_defined, BAR, baz value)

The leading @ sign turns off command echoing and : is the actual command, a shell no-op stub.

Showing target name

The check_defined function can be improved to also output the target name (provided through the $@ variable):

check_defined = \
    $(strip $(foreach 1,$1, \
        $(call __check_defined,$1,$(strip $(value 2)))))
__check_defined = \
    $(if $(value $1),, \
        $(error Undefined $1$(if $2, ($2))$(if $(value @), \
                required by target `$@')))

So that, now a failed check produces a nicely formatted output:

Makefile:7: *** Undefined BAR (baz value) required by target `foo'.  Stop.

check-defined-MY_FLAG special target

Personally I would use the simple and straightforward solution above. However, for example, this answer suggests using a special target to perform the actual check. One could try to generalize that and define the target as an implicit pattern rule:

# Check that a variable specified through the stem is defined and has
# a non-empty value, die with an error otherwise.
#   %: The name of the variable to test.
check-defined-% : __check_defined_FORCE
    @:$(call check_defined, $*, target-specific)

# Since pattern rules can't be listed as prerequisites of .PHONY,
# we use the old-school and hackish FORCE workaround.
# You could go without this, but otherwise a check can be missed
# in case a file named like `check-defined-...` exists in the root 
# directory, e.g. left by an accidental `make -t` invocation.
.PHONY : __check_defined_FORCE
__check_defined_FORCE :


foo :|check-defined-BAR

Notice that the check-defined-BAR is listed as the order-only (|...) prerequisite.


  • (arguably) a more clean syntax


I believe, these limitations can be overcome using some eval magic and secondary expansion hacks, although I'm not sure it's worth it.

CRON job to run on the last day of the month

There's a slightly shorter method that can be used similar to one of the ones above. That is:

[ $(date -d +1day +%d) -eq 1 ] && echo "last day of month"

Also, the crontab entry could be update to only check on the 28th to 31st as it's pointless running it the other days of the month. Which would give you:

0 23 28-31 * * [ $(date -d +1day +%d) -eq 1 ] &&

T-SQL: Deleting all duplicate rows but keeping one

You didn't say what version you were using, but in SQL 2005 and above, you can use a common table expression with the OVER Clause. It goes a little something like this:

WITH cte AS (
  SELECT[foo], [bar], 
     row_number() OVER(PARTITION BY foo, bar ORDER BY baz) AS [rn]
DELETE cte WHERE [rn] > 1

Play around with it and see what you get.

(Edit: In an attempt to be helpful, someone edited the ORDER BY clause within the CTE. To be clear, you can order by anything you want here, it needn't be one of the columns returned by the cte. In fact, a common use-case here is that "foo, bar" are the group identifier and "baz" is some sort of time stamp. In order to keep the latest, you'd do ORDER BY baz desc)

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        //textfield.setText(null); //or use this

Also See
How to Use Buttons

How does jQuery work when there are multiple elements with the same ID value?

jQuery's id selector only returns one result. The descendant and multiple selectors in the second and third statements are designed to select multiple elements. It's similar to:

Statement 1

var length = document.getElementById('a').length;

...Yields one result.

Statement 2

var length = 0;
for (i=0; i<document.body.childNodes.length; i++) {
    if (document.body.childNodes.item(i).id == 'a') {

...Yields two results.

Statement 3

var length = document.getElementById('a').length + document.getElementsByTagName('div').length;

...Also yields two results.

ASP.NET MVC3 - textarea with @Html.EditorFor

@Html.TextAreaFor(model => model.Text)

jQuery DataTable overflow and text-wrapping issues

I faced the same problem of text wrapping, solved it by changing the css of table class in DT_bootstrap.css. I introduced last two css lines table-layout and word-break.

   table.table {
    clear: both;
    margin-bottom: 6px !important;
    max-width: none !important;
    table-layout: fixed;
    word-break: break-all;

How should I log while using multiprocessing in Python?

I liked zzzeek's answer. I would just substitute the Pipe for a Queue since if multiple threads/processes use the same pipe end to generate log messages they will get garbled.

Xcode build failure "Undefined symbols for architecture x86_64"

I also encountered the same problem , the above methods will not work . I accidentally deleted the files in the following directory on it . enter image description here



enter image description here

What is the purpose of Node.js module.exports and how do you use it?

the module.exports property or the exports object allows a module to select what should be shared with the application

enter image description here

I have a video on module_export available here

Pass a PHP variable value through an HTML form

Try that

First place

global $var;
$var = 'value';

Second place

global $var;
if (isset($_POST['save_exit']))
    echo $var; 

Or if you want to be more explicit you can use the globals array:

$GLOBALS['var'] = 'test';

// after that
echo $GLOBALS['var'];

And here is third options which has nothing to do with PHP global that is due to the lack of clarity and information in the question. So if you have form in HTML and you want to pass "variable"/value to another PHP script you have to do the following:

HTML form

<form action="script.php" method="post">
    <input type="text" value="<?php echo $var?>" name="var" />
    <input type="submit" value="Send" />

PHP script ("script.php")


$var = $_POST['var'];
echo $var;


What is difference between png8 and png24

While making image with fully transparent background in PNG-8, the outline of the image looks prominent with little white bits. But in PNG-24 the outline is gone and looks perfect. Transparency in PNG-24 is greater and cleaner than PNG-8.

PNG-8 contains 256 colors, while PNG-24 contains 16 million colors.

File size is almost double in PNG-24 than PNG-8.

Find size of Git repository

Note that, since git 1.8.3 (April, 22d 2013):

"git count-objects" learned "--human-readable" aka "-H" option to show various large numbers in Ki/Mi/GiB scaled as necessary.

That could be combined with the -v option mentioned by Jack Morrison in his answer.

git gc
git count-objects -vH

(git gc is important, as mentioned by A-B-B's answer)

Plus (still git 1.8.3), the output is more complete:

"git count-objects -v" learned to report leftover temporary packfiles and other garbage in the object store.

How to convert all tables from MyISAM into InnoDB?


// Convert all MyISAM tables to INNODB tables in all non-special databases.
// Note: With MySQL less than 5.6, tables with a fulltext search index cannot be converted to INNODB and will be skipped.

if($argc < 4)
    exit("Usage: {$argv[0]} <host> <username> <password>\n");
$host = $argv[1];
$username = $argv[2];
$password = $argv[3];

// Connect to the database.
if(!mysql_connect($host, $username, $password))
    exit("Error opening database. " . mysql_error() . "\n");

// Get all databases except special ones that shouldn't be converted.
$databases = mysql_query("SHOW databases WHERE `Database` NOT IN ('mysql', 'information_schema', 'performance_schema')");
if($databases === false)
    exit("Error showing databases. " . mysql_error() . "\n");

while($db = mysql_fetch_array($databases))
    // Select the database.
        exit("Error selecting database: {$db[0]}. " . mysql_error() . "\n");
    printf("Database: %s\n", $db[0]);

    // Get all MyISAM tables in the database.
    $tables = mysql_query("SHOW table status WHERE Engine = 'MyISAM'");
    if($tables === false)
        exit("Error showing tables. " . mysql_error() . "\n");

    while($tbl = mysql_fetch_array($tables))
        // Convert the table to INNODB.
        printf("--- Converting %s\n", $tbl[0]);
        if(mysql_query("ALTER TABLE `{$tbl[0]}` ENGINE = INNODB") === false)
            printf("--- --- Error altering table: {$tbl[0]}. " . mysql_error() . "\n");



php Replacing multiple spaces with a single space

$output = preg_replace('/\s+/', ' ',$input);

\s is shorthand for [ \t\n\r]. Multiple spaces will be replaced with single space.

How to make this Header/Content/Footer layout using CSS?

Try This

<!DOCTYPE html>



<title>Sticky Header and Footer</title>

<style type="text/css">

/* Reset body padding and margins */

body {


/* Make Header Sticky */

#header_container {


    border:1px solid #666;






#header {


    margin:0 auto;



/* CSS for the content of page. I am giving top and bottom padding of 80px to make sure the header and footer do not overlap the content.*/

#container {

    margin:0 auto;


    padding:80px 0;



#content {


/* Make Footer Sticky */

#footer_container {


    border:1px solid #666;






#footer {


    margin:0 auto;







<!-- BEGIN: Sticky Header -->
<div id="header_container">

    <div id="header">
        Header Content

<!-- END: Sticky Header -->

<!-- BEGIN: Page Content -->
<div id="container">

    <div id="content">

        <br /><br />
            blah blah blah..

<!-- END: Page Content -->

<!-- BEGIN: Sticky Footer -->
<div id="footer_container">

    <div id="footer">

        Footer Content



<!-- END: Sticky Footer -->



Can we have multiple <tbody> in same <table>?

Martin Joiner's problem is caused by a misunderstanding of the <caption> tag.

The <caption> tag defines a table caption.

The <caption> tag must be the first child of the <table> tag.

You can specify only one caption per table.

Also, note that the scope attribute should be placed on a <th> element and not on a <tr> element.

The proper way to write a multi-header multi-tbody table would be something like this :

<table id="dinner_table">_x000D_
    <caption>This is the only correct place to put a caption.</caption>_x000D_
        <tr class="header">_x000D_
            <th colspan="2" scope="col">First Half of Table (British Dinner)</th>_x000D_
            <th scope="row">1</th>_x000D_
            <th scope="row">2</th>_x000D_
            <th scope="row">3</th>_x000D_
            <th scope="row">4</th>_x000D_
        <tr class="header">_x000D_
            <th colspan="2" scope="col">Second Half of Table (Italian Dinner)</th>_x000D_
            <th scope="row">5</th>_x000D_
            <th scope="row">6</th>_x000D_
            <th scope="row">7</th>_x000D_
            <th scope="row">8</th>_x000D_

Counting the number of option tags in a select tag in jQuery

Your question is a little confusing, but assuming you want to display the number of options in a panel:

<div id="preview"></div>


$(function() {
  $("#preview").text($("#input1 option").length + " items");

Not sure I understand the rest of your question.

What is the equivalent of ngShow and ngHide in Angular 2+?

If you just want to use the symmetrical hidden/shown directives that AngularJS came with, I suggest writing an attribute directive to simplify the templates like so (tested with Angular 7):

import { Directive, Input, HostBinding } from '@angular/core';

@Directive({ selector: '[shown]' })
export class ShownDirective {
  @Input() public shown: boolean;

  public get attrHidden(): string | null {
    return this.shown ? null : 'hidden';

Many of the other solutions are correct. You should use *ngIf where ever possible. Using the hidden attribute can have unexpected styles applied, but unless you are writing components for others, you probably know if it is. So for this shown directive to work, you will also want to make sure that you add:

[hidden]: {
  display: none !important;

to your global styles somewhere.

With these you can use the directive like so:

<div [shown]="myVar">stuff</div>

with the symmetrical (and opposite) version like so:

<div [hidden]="myVar">stuff</div>

To add on to the shoulds - yous should also us a prefix like so [acmeShown] vs just [shown].

The main reason I used a shown attribute directive is for converting AngularJS code to Angular -AND- when the content that is being hidden contains container components that cause XHR round trips. The reason I don't just use [hidden]="!myVar" is that often enough it is more complicated like: [hidden]="!(myVar || yourVar) && anotherVar" - yes I can invert that, but it is more error prone.[shown]` is simply easier to think about.

How can I get the value of a registry key from within a batch script?

Thanks, i just need to use:

SETLOCAL EnableExtensions

And put a:


Into the REG QUERY called in the FOR command. Thanks a lot again! :)

What does '&' do in a C++ declaration?

Here, & is not used as an operator. As part of function or variable declarations, & denotes a reference. The C++ FAQ Lite has a pretty nifty chapter on references.

How do I check if a string contains another string in Swift?

// Search string exist in employee name finding.
var empName:NSString! = employeeDetails[filterKeyString] as NSString

Case sensitve search.
let rangeOfSearchString:NSRange! = empName.rangeOfString(searchString, options: NSStringCompareOptions.CaseInsensitiveSearch)

// Not found.
if rangeOfSearchString.location != Foundation.NSNotFound
    // search string not found in employee name.
// Found
    // search string found in employee name.

Bootstrap datepicker disabling past dates without current date

In html

<input class="required form-control" id="d_start_date" name="d_start_date" type="text" value="">

In Js side

<script type="text/javascript">
        $(document).ready(function () {
        var dateToday = new Date();

            autoclose: true,
            startDate: dateToday


Evaluating string "3*(4+2)" yield int 18

If you want to evaluate a string expression use the below code snippet.

using System.Data;

DataTable dt = new DataTable();
var v = dt.Compute("3 * (2+4)","");

What is the difference between Session.Abandon() and Session.Clear()

this code works and dont throw any exception:

Session["tempKey1"] = "tempValue1";

One thing to note here that Session.Clear remove items immediately but Session.Abandon marks the session to be abandoned at the end of the current request. That simply means that suppose you tried to access value in code just after the session.abandon command was executed, it will be still there. So do not get confused if your code is just not working even after issuing session.abandon command and immediately doing some logic with the session.

MySQL duplicate entry error even though there is no duplicate entry

For me a noop on table has been enough (was already InnoDB):


How to pass a file path which is in assets folder to File(String path)?

Unless you unpack them, assets remain inside the apk. Accordingly, there isn't a path you can feed into a File. The path you've given in your question will work with/in a WebView, but I think that's a special case for WebView.

You'll need to unpack the file or use it directly.

If you have a Context, you can use context.getAssets().open("myfoldername/myfilename"); to open an InputStream on the file. With the InputStream you can use it directly, or write it out somewhere (after which you can use it with File).

Multiple cases in switch statement

There is no syntax in C++ nor C# for the second method you mentioned.

There's nothing wrong with your first method. If however you have very big ranges, just use a series of if statements.

Simple check for SELECT query empty result

To summarize the below posts a bit:

If all you care about is if at least one matching row is in the DB then use exists as it is the most efficient way of checking this: it will return true as soon as it finds at least one matching row whereas count, etc will find all matching rows.

If you actually need to use the data for processing or if the query has side effects, or if you need to know the actual total number of rows then checking the ROWCOUNT or count is probably the best way on hand.

How to check "hasRole" in Java Code with Spring Security?

User Roles can be checked using following ways:

  1. Using call static methods in SecurityContextHolder:

    Authentication auth = SecurityContextHolder.getContext().getAuthentication(); if (auth != null && auth.getAuthorities().stream().anyMatch(role -> role.getAuthority().equals("ROLE_NAME"))) { //do something}

  2. Using HttpServletRequest

public String getUsers(HttpServletRequest request) {
    if (request.isUserInRole("ROLE_NAME")) {

Get class list for element with jQuery

Here is a jQuery plugin which will return an array of all the classes the matched element(s) have

;!(function ($) {
    $.fn.classes = function (callback) {
        var classes = [];
        $.each(this, function (i, v) {
            var splitClassName = v.className.split(/\s+/);
            for (var j = 0; j < splitClassName.length; j++) {
                var className = splitClassName[j];
                if (-1 === classes.indexOf(className)) {
        if ('function' === typeof callback) {
            for (var i in classes) {
        return classes;

Use it like


In your case returns

["Lorem", "ipsum", "dolor_spec", "sit", "amet"]

You can also pass a function to the method to be called on each class

    function(c) {
        // do something with each class

Here is a jsFiddle I set up to demonstrate and test

Minified Javascript

;!function(e){e.fn.classes=function(t){var n=[];e.each(this,function(e,t){var r=t.className.split(/\s+/);for(var i in r){var s=r[i];if(-1===n.indexOf(s)){n.push(s)}}});if("function"===typeof t){for(var r in n){t(n[r])}}return n}}(jQuery);

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

If you are using IPython, then you need to type "foo??"

In [19]: foo??
Signature: foo(arg1, arg2)
def foo(arg1,arg2):
    #do something with args
    a = arg1 + arg2
    return a

File:      ~/Desktop/<ipython-input-18-3174e3126506>
Type:      function

HTML&CSS + Twitter Bootstrap: full page layout or height 100% - Npx

I know it's late in the day but might help someone else!

body,html {
  height: 100%;

.contentarea {

  * replace 160px with the sum of height of all other divs 
  * inc padding, margins etc 
  min-height: calc(100% - 160px); 

Use PHP composer to clone git repo

In my case, I use Symfony2.3.x and the minimum-stability parameter is by default "stable" (which is good). I wanted to import a repo not in packagist but had the same issue "Your requirements could not be resolved to an installable set of packages.". It appeared that the composer.json in the repo I tried to import use a minimum-stability "dev".

So to resolve this issue, don't forget to verify the minimum-stability. I solved it by requiring a dev-master version instead of master as stated in this post.

How do I make a semi transparent background?

If you want to make transparent background is gray, pls try:


how to convert string into dictionary in python 3.*?

  1. literal_eval, a somewhat safer version of eval (will only evaluate literals ie strings, lists etc):

    from ast import literal_eval
    python_dict = literal_eval("{'a': 1}")
  2. json.loads but it would require your string to use double quotes:

    import json
    python_dict = json.loads('{"a": 1}')

Cannot open database "test" requested by the login. The login failed. Login failed for user 'xyz\ASPNET'

I used Windows authentication to connect to local database .mdf file and my local server was sql server 2014. My problem solved using this connection string:

string sqlString = " Data Source = (LocalDB)\\MSSQLLocalDB;" + "AttachDbFilename = F:\\.........\\myDatabase.mdf; Integrated Security = True; Connect Timeout = 30";

Installing specific package versions with pip

There are 2 ways you may install any package with version:- A). pip install -Iv package-name == version B). pip install -v package-name == version

For A

Here, if you're using -I option while installing(when you don't know if the package is already installed) (like 'pip install -Iv pyreadline == 2.* 'or something), you would be installing a new separate package with the same existing package having some different version.

For B

  1. At first, you may want to check for no broken requirements. pip check

2.and then see what's already installed by pip list

3.if the list of the packages contain any package that you wish to install with specific version then the better option is to uninstall the package of this version first, by pip uninstall package-name

4.And now you can go ahead to reinstall the same package with a specific version, by pip install -v package-name==version e.g. pip install -v pyreadline == 2.*

How do I convert a javascript object array to a string array of the object attribute I want?

If your array of objects is items, you can do:

var items = [{_x000D_
  id: 1,_x000D_
  name: 'john'_x000D_
}, {_x000D_
  id: 2,_x000D_
  name: 'jane'_x000D_
}, {_x000D_
  id: 2000,_x000D_
  name: 'zack'_x000D_
var names = {_x000D_
  return item['name'];_x000D_

Documentation: map()

Fastest way to convert string to integer in PHP

You can simply convert long string into integer by using FLOAT

$float = (float)$num;

Or if you want integer not floating val then go with

$float = (int)$num;

For ex.

(int)   "1212.3"   = 1212 
(float) "1212.3"   = 1212.3

Filter data.frame rows by a logical condition

No one seems to have included the which function. It can also prove useful for filtering.

expr[which(expr$cell == 'hesc'),]

This will also handle NAs and drop them from the resulting dataframe.

Running this on a 9840 by 24 dataframe 50000 times, it seems like the which method has a 60% faster run time than the %in% method.

How to remove hashbang from url?

Quoting the docs.

The default mode for vue-router is hash mode - it uses the URL hash to simulate a full URL so that the page won't be reloaded when the URL changes.

To get rid of the hash, we can use the router's history mode, which leverages the history.pushState API to achieve URL navigation without a page reload:

const router = new VueRouter({
  mode: 'history',
  routes: [...]

When using history mode, the URL will look "normal," e.g. Beautiful!

Here comes a problem, though: Since our app is a single page client side app, without a proper server configuration, the users will get a 404 error if they access directly in their browser. Now that's ugly.

Not to worry: To fix the issue, all you need to do is add a simple catch-all fallback route to your server. If the URL doesn't match any static assets, it should serve the same index.html page that your app lives in. Beautiful, again!

npm not working after clearing cache

try this one npm cache clean --force after that run npm cache verify

What does Docker add to lxc-tools (the userspace LXC tools)?

Let's take a look at the list of Docker's technical features, and check which ones are provided by LXC and which ones aren't.


1) Filesystem isolation: each process container runs in a completely separate root filesystem.

Provided with plain LXC.

2) Resource isolation: system resources like cpu and memory can be allocated differently to each process container, using cgroups.

Provided with plain LXC.

3) Network isolation: each process container runs in its own network namespace, with a virtual interface and IP address of its own.

Provided with plain LXC.

4) Copy-on-write: root filesystems are created using copy-on-write, which makes deployment extremely fast, memory-cheap and disk-cheap.

This is provided by AUFS, a union filesystem that Docker depends on. You could set up AUFS yourself manually with LXC, but Docker uses it as a standard.

5) Logging: the standard streams (stdout/stderr/stdin) of each process container is collected and logged for real-time or batch retrieval.

Docker provides this.

6) Change management: changes to a container's filesystem can be committed into a new image and re-used to create more containers. No templating or manual configuration required.

"Templating or manual configuration" is a reference to LXC, where you would need to learn about both of these things. Docker allows you to treat containers in the way that you're used to treating virtual machines, without learning about LXC configuration.

7) Interactive shell: docker can allocate a pseudo-tty and attach to the standard input of any container, for example to run a throwaway interactive shell.

LXC already provides this.

I only just started learning about LXC and Docker, so I'd welcome any corrections or better answers.

How to customize the background/border colors of a grouped table view cell?

Thanks for this super helpful post. In case anyone out there (like me!) wants to just have a completely empty cell background in lieu of customizing it through images/text/other content in IB and cannot figure out how the hell to get rid of the dumb border/padding/background even though you set it to clear in IB... here's the code I used that did the trick!

- (UITableViewCell *) tableView: (UITableView *) tableView cellForRowAtIndexPath: (NSIndexPath *) indexPath {

    static NSString *cellId = @"cellId";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: cellId];
    if (cell == nil) {
        [[NSBundle mainBundle] loadNibNamed:@"EditTableViewCell" owner:self options:nil];
        cell = cellIBOutlet;
        self.cellIBOutlet = nil;

    cell.backgroundView = [[[UIView alloc] initWithFrame: CGRectZero] autorelease];
    [cell.backgroundView setNeedsDisplay];

    ... any other cell customizations ...

    return cell;

Hopefully that'll help someone else! Seems to work like a charm.

$(form).ajaxSubmit is not a function

Ajax Submit form with out page refresh by using jquery ajax method first include library jquery.js and jquery-form.js then create form in html:

<form action="postpage.php" method="POST" id="postForm" >

<div id="flash_success"></div>

<input type="text" name="name" />
<input type="password" name="pass" />
<input type="text" name="email" />

<input type="submit" name="btn" value="Submit" />

  var options = { 
        target:        '#flash_success',  // your response show in this ID
        beforeSubmit:  callValidationFunction,
        success:       YourResponseFunction  
    // bind to the form's submit event
        jQuery('#postForm').submit(function() { 
            return false; 

function callValidationFunction()
 //  validation code for your form HERE

function YourResponseFunction(responseText, statusText, xhr, $form)
        $('#flash_success').html('Your Success Message Here!!!');
        $('body,html').animate({scrollTop: 0}, 800);

        $('#flash_success').html('Error Msg Here');


Where is svcutil.exe in Windows 7?

I don't think it is very important to find the location of Svcutil.exe. You can use Visual Studio Command prompt to execute directly without its absolute path,

svcutil.exe /language:[vb|cs] /out:[YourClassName].[cs|vb] /config:[YourAppConfigFile.config] [YourServiceAddress]

svcutil.exe /language:cs /out:MyClientClass.cs /config:app.config http://localhost:8370/MyService/

How to catch a unique constraint error in a PL/SQL block?

I'm sure you have your reasons, but just in case... you should also consider using a "merge" query instead:

    merge into some_table st
    using (select 'some' name, 'values' value from dual) v
    on (
    when matched then update set st.value=v.value
    when not matched then insert (name, value) values (, v.value);

(modified the above to be in the begin/end block; obviously you can run it independantly of the procedure too).

How to access property of anonymous type in C#?

If you're storing the object as type object, you need to use reflection. This is true of any object type, anonymous or otherwise. On an object o, you can get its type:

Type t = o.GetType();

Then from that you look up a property:

PropertyInfo p = t.GetProperty("Foo");

Then from that you can get a value:

object v = p.GetValue(o, null);

This answer is long overdue for an update for C# 4:

dynamic d = o;
object v = d.Foo;

And now another alternative in C# 6:

object v = o?.GetType().GetProperty("Foo")?.GetValue(o, null);

Note that by using ?. we cause the resulting v to be null in three different situations!

  1. o is null, so there is no object at all
  2. o is non-null but doesn't have a property Foo
  3. o has a property Foo but its real value happens to be null.

So this is not equivalent to the earlier examples, but may make sense if you want to treat all three cases the same.

Default argument values in JavaScript functions

You cannot add default values for function parameters. But you can do this:

function tester(paramA, paramB){
 if (typeof paramA == "undefined"){
   paramA = defaultValue;
 if (typeof paramB == "undefined"){
   paramB = defaultValue;

How to wait for 2 seconds?

How about this?

WAITFOR DELAY '00:00:02';

If you have "00:02" it's interpreting that as Hours:Minutes.

Replacing few values in a pandas dataframe column with another value

Just wanted to show that there is no performance difference between the 2 main ways of doing it:

df = pd.DataFrame(np.random.randint(0,10,size=(100, 4)), columns=list('ABCD'))

def loc():
    df1.loc[df1["A"] == 2] = 5
%timeit loc
19.9 ns ± 0.0873 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

def replace():
%timeit replace
19.6 ns ± 0.509 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

Scrollable Menu with Bootstrap - Menu expanding its container when it should not

I think you can simplify this by just adding the necessary CSS properties to your special scrollable menu class..


.scrollable-menu {
    height: auto;
    max-height: 200px;
    overflow-x: hidden;


       <ul class="dropdown-menu scrollable-menu" role="menu">
          <li><a href="#">Action</a></li>
          <li><a href="#">Another action</a></li>
          <li><a href="#">Something else here</a></li>
          <li><a href="#">Action</a></li>
          <li><a href="#">Action</a></li>
          <li><a href="#">Another action</a></li>

Working example:

Bootstrap 4

Another example for Bootstrap 4 using flexbox

Call parent method from child class c#

To access properties and methods of a parent class use the base keyword. So in your child class LoadData() method you would do this:

public class Child : Parent 
    public void LoadData() 
        base.MyMethod(); // call method of parent class
        base.CurrentRow = 1; // set property of parent class
        // other stuff...

Note that you would also have to change the access modifier of your parent MyMethod() to at least protected for the child class to access it.

Showing all errors and warnings

Set these on php.ini:

;display_startup_errors = On
display_errors =on
html_errors= on

From your PHP page, use a suitable filter for error reporting.


Filers can be made according to requirements.


Cloudfront custom-origin distribution returns 502 "ERROR The request could not be satisfied." for some URLs

Beware the Origin Protocol Policy:

For HTTPS viewer requests that CloudFront forwards to this origin, one of the domain names in the SSL certificate on your origin server must match the domain name that you specify for Origin Domain Name. Otherwise, CloudFront responds to the viewer requests with an HTTP status code 502 (Bad Gateway) instead of returning the requested object.

In most cases, you probably want CloudFront to use "HTTP Only", since it fetches objects from a server probably hosted with Amazon too. No need for additional HTTPS complexity at this step.

Note that this is different to the Viewer Protocol Policy. You can read more about the differences between the two here.

calling java methods in javascript code

When it is on server side, use web services - maybe RESTful with JSON.

  • create a web service (for example with Tomcat)
  • call its URL from JavaScript (for example with JQuery or dojo)

When Java code is in applet you can use JavaScript bridge. The bridge between the Java and JavaScript programming languages, known informally as LiveConnect, is implemented in Java plugin. Formerly Mozilla-specific LiveConnect functionality, such as the ability to call static Java methods, instantiate new Java objects and reference third-party packages from JavaScript, is now available in all browsers.

Below is example from documentation. Look at methodReturningString.

Java code:

public class MethodInvocation extends Applet {
    public void noArgMethod() { ... }
    public void someMethod(String arg) { ... }
    public void someMethod(int arg) { ... }
    public int  methodReturningInt() { return 5; }
    public String methodReturningString() { return "Hello"; }
    public OtherClass methodReturningObject() { return new OtherClass(); }

public class OtherClass {
    public void anotherMethod();

Web page and JavaScript code:

<applet id="app"
        code="MethodInvocation" ...>
<script language="javascript">
    var five = app.methodReturningInt();
    var hello = app.methodReturningString();

How to display Base64 images in HTML?

You need to specify correct Content-type, Content-encoding and charset like


according to the syntax of the data URI scheme:

 data:[<media type>][;charset=<character set>][;base64],<data>

How to make a PHP SOAP call using the SoapClient class

You can use SOAP services this way too:

//Create the client object
$soapclient = new SoapClient('');

//Use the functions of the client, the params of the function are in 
//the associative array
$params = array('CountryName' => 'Spain', 'CityName' => 'Alicante');
$response = $soapclient->getWeather($params);


// Get the Cities By Country
$param = array('CountryName' => 'Spain');
$response = $soapclient->getCitiesByCountry($param);


This is an example with a real service, and it works when the url is up.

Just in case the is down.

Here is another example using the example web service from W3C XML Web Services example, you can find more information on the link.

//Create the client object
$soapclient = new SoapClient('');

//Use the functions of the client, the params of the function are in
//the associative array
$params = array('Celsius' => '25');
$response = $soapclient->CelsiusToFahrenheit($params);


// Get the Celsius degrees from the Farenheit
$param = array('Fahrenheit' => '25');
$response = $soapclient->FahrenheitToCelsius($param);


This is working and returning the converted temperature values.

Hope this helps.

Mongoose delete array element in document and save

This is working for me and really very helpful.

SubCategory.update({ _id: { $in: (obj) {
            return mongoose.Types.ObjectId(obj);
    } },
        $pull: {
            coupon: couponId,
    }, { multi: true }, function (err, numberAffected) {
        if(err) {
            return callback({

I have a model which name is SubCategory and I want to remove Coupon from this category Array. I have an array of categories so I have used arrOfSubCategory. So I fetch each array of object from this array with map function with the help of $in operator.

Javascript select onchange='this.form.submit()'

Use :

<select onchange="myFunction()">

    function myFunction() {

Exception : peer not authenticated

In my case I was using a JDK 8 client and the server was using insecure old ciphers. The server is Apache and I added this line to the Apache config:


You should use a tool like this to verify your SSL configuration is currently secure:

Brew doctor says: "Warning: /usr/local/include isn't writable."

Take ownership of it and everything in it.

Mac OS High Sierra or newer: (ty to Kirk in the comments below)

$ sudo chown -R $(whoami) $(brew --prefix)/*

Previous versions of macos:

$ sudo chown -R $USER:admin /usr/local/include

Then do another

$ brew doctor

FileSystemWatcher Changed event is raised twice

Event if not asked, it is a shame there are no ready solution samples for F#. To fix this here is my recipe, just because I can and F# is a wonderful .NET language.

Duplicated events are filtered out using FSharp.Control.Reactive package, which is just a F# wrapper for reactive extensions. All that can be targeted to full framework or netstandard2.0:

let createWatcher path filter () =
    new FileSystemWatcher(
        Path = path,
        Filter = filter,
        EnableRaisingEvents = true,
        SynchronizingObject = null // not needed for console applications

let createSources (fsWatcher: FileSystemWatcher) =
    // use here needed events only. 
    // convert `Error` and `Renamed` events to be merded
    [| fsWatcher.Changed :> IObservable<_>
       fsWatcher.Deleted :> IObservable<_>
       fsWatcher.Created :> IObservable<_>
       //fsWatcher.Renamed |> renamedToNeeded
       //fsWatcher.Error   |> errorToNeeded
    |] |> Observable.mergeArray

let handle (e: FileSystemEventArgs) =
    printfn "handle %A event '%s' '%s' " e.ChangeType e.Name e.FullPath 

let watch path filter throttleTime =
    // disposes watcher if observer subscription is disposed
    Observable.using (createWatcher path filter) createSources
    // filter out multiple equal events
    |> Observable.distinctUntilChanged
    // filter out multiple Changed
    |> Observable.throttle throttleTime
    |> Observable.subscribe handle

let main _args =
    let path = @"C:\Temp\WatchDir"
    let filter = "*.zip"
    let throttleTime = TimeSpan.FromSeconds 10.
    use _subscription = watch path filter throttleTime
    System.Console.ReadKey() |> ignore
    0 // return an integer exit code

Extract Number from String in Python

This code works fine. There is definitely some other problem:

>>> str1 = "3158 reviews"
>>> print (re.findall('\d+', str1 ))

How do I concatenate a boolean to a string in Python?

Using the so called f strings:

answer = True
myvar = f"the answer is {answer}"

Then if I do


I will get:

the answer is True

I like f strings because one does not have to worry about the order in which the variables will appear in the printed text, which helps in case one has multiple variables to be printed as strings.

successful/fail message pop up box after submit?

You are echoing outside the body tag of your HTML. Put your echos there, and you should be fine.

Also, remove the onclick="alert()" from your submit. This is the cause for your first undefined message.

  $posted = false;
  if( $_POST ) {
    $posted = true;

    // Database stuff here...
    // $result = mysql_query( ... )
    $result = $_POST['name'] == "danny"; // Dummy result


    if( $posted ) {
      if( $result ) 
        echo "<script type='text/javascript'>alert('submitted successfully!')</script>";
        echo "<script type='text/javascript'>alert('failed!')</script>";
    <form action="" method="post">
      Name:<input type="text" id="name" name="name"/>
      <input type="submit" value="submit" name="submit"/>