Programs & Examples On #Phpundercontrol

phpUnderControl is a PHP centric add-on to the CruiseControl CI server

HttpServletRequest - how to obtain the referring URL?

The URLs are passed in the request: request.getRequestURL().

If you mean other sites that are linking to you? You want to capture the HTTP Referrer, which you can do by calling:


How to convert byte array to string

You can do it without dealing with encoding by using BlockCopy:

char[] chars = new char[bytes.Length / sizeof(char)];
System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
string str = new string(chars);

How to get a complete list of object's methods and attributes?

Only to supplement:

  1. dir() is the most powerful/fundamental tool. (Most recommended)
  2. Solutions other than dir() merely provide their way of dealing the output of dir().

    Listing 2nd level attributes or not, it is important to do the sifting by yourself, because sometimes you may want to sift out internal vars with leading underscores __, but sometimes you may well need the __doc__ doc-string.

  3. __dir__() and dir() returns identical content.
  4. __dict__ and dir() are different. __dict__ returns incomplete content.
  5. IMPORTANT: __dir__() can be sometimes overwritten with a function, value or type, by the author for whatever purpose.

    Here is an example:

    \\...\\ in traverse(self, mod, search_attributes)
    445             if prefix in traversed_mod_names:
    446                 continue
    447             names = dir(m)
    448             for name in names:
    449                 obj = getattr(m,name)

    TypeError: descriptor __dir__ of 'object' object needs an argument

    The author of PyTorch modified the __dir__() method to something that requires an argument. This modification makes dir() fail.

  6. If you want a reliable scheme to traverse all attributes of an object, do remember that every pythonic standard can be overridden and may not hold, and every convention may be unreliable.

how to use #ifdef with an OR condition?

Like this

#if defined(LINUX) || defined(ANDROID)

Any way to limit border length?

CSS generated content can solve this for you:

div {_x000D_
  position: relative;_x000D_
/* Main div for border to extend to 50% from bottom left corner */_x000D_
div:after {_x000D_
  content: "";_x000D_
  background: black;_x000D_
  position: absolute;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  height: 50%;_x000D_
  width: 1px;_x000D_
<div>Lorem Ipsum</div>

(note - the content: ""; declaration is necessary in order for the pseudo-element to render)

Twig ternary operator, Shorthand if-then-else

Support for the extended ternary operator was added in Twig 1.12.0.

  1. If foo echo yes else echo no:

    {{ foo ? 'yes' : 'no' }}
  2. If foo echo it, else echo no:

    {{ foo ?: 'no' }}


    {{ foo ? foo : 'no' }}
  3. If foo echo yes else echo nothing:

    {{ foo ? 'yes' }}


    {{ foo ? 'yes' : '' }}
  4. Returns the value of foo if it is defined and not null, no otherwise:

    {{ foo ?? 'no' }}
  5. Returns the value of foo if it is defined (empty values also count), no otherwise:

    {{ foo|default('no') }}

sudo: port: command not found

I found the answer in the official website

$ vi ~/.profile

# add the following line
export PATH=/opt/local/bin:/opt/local/sbin:$PATH

And now restart the terminal or type source !$ (equivalent to source ~/.profile)

SeekBar and media player in android

To create a 'connection' between SeekBar and MediaPlayer you need first to get your current recording max duration and set it to your seek bar.

mSeekBar.setMax(mFileDuration/1000); // where mFileDuration is mMediaPlayer.getDuration();

After you initialise your MediaPlayer and for example press play button, you should create handler and post runnable so you can update your SeekBar (in the UI thread itself) with the current position of your MediaPlayer like this :

private Handler mHandler = new Handler();
//Make sure you update Seekbar on UI thread
MainActivity.this.runOnUiThread(new Runnable() {

    public void run() {
        if(mMediaPlayer != null){
            int mCurrentPosition = mMediaPlayer.getCurrentPosition() / 1000;
        mHandler.postDelayed(this, 1000);

and update that value every second.

If you need to update the MediaPlayer's position while user drag your SeekBar you should add OnSeekBarChangeListener to your SeekBar and do it there :

        mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {

        public void onStopTrackingTouch(SeekBar seekBar) {


        public void onStartTrackingTouch(SeekBar seekBar) {


            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {                
                if(mMediaPlayer != null && fromUser){
                    mMediaPlayer.seekTo(progress * 1000);

And that should do the trick! : )

EDIT: One thing which I've noticed in your code, don't do :

public MainActivity() {
    mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
    mFileName += "/audiorecordtest.3gp";

make all initialisations in your onCreate(); , do not create constructors of your Activity.

How do I get the currently-logged username from a Windows service in .NET?

Try WindowsIdentity.GetCurrent(). You need to add reference to System.Security.Principal

Javascript / Chrome - How to copy an object from the webkit inspector as code

Follow the following steps:

  1. Output the object with console.log from your code, like so: console.log(myObject)
  2. Right click on the object and click "Store as Global Object". Chrome would print the name of the variable at this point. Let's assume it's called "temp1".
  3. In the console, type: JSON.stringify(temp1).
  4. At this point you will see the entire JSON object as a string that you can copy/paste.
  5. You can use online tools like to prettify your string at this point.

Android map v2 zoom to show all the markers

I worked the same problem for showing multiple markers in Kotlin using a fragment

first declare a list of markers

private lateinit var markers: MutableList<Marker>

initialize this in the oncreate method of the frament

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
                         ): View? {
    //initialize markers list

    markers = mutableListOf()
    return inflater.inflate(R.layout.fragment_driver_map, container, false)

on the OnMapReadyCallback add the markers to the markers list

private val callback = OnMapReadyCallback { googleMap ->

    map = googleMap



Still on the callback

//create builder
    val builder = LatLngBounds.builder()

    //loop through the markers list
    for (marker in markers) {

    //create a bound
    val bounds =

    //set a 200 pixels padding from the edge of the screen
    val cu = CameraUpdateFactory.newLatLngBounds(bounds,200)
    //move and animate the camera
    //animate camera by providing zoom and duration args, callBack set to null
    map.animateCamera(CameraUpdateFactory.zoomTo(10f), 2000, null)

Merry coding guys

Git refusing to merge unrelated histories on rebase

For this, enter the command:

git pull origin branchname --allow-unrelated-histories

For example,

git pull origin master --allow-unrelated-histories


GitHub unrelated histories issue

SmartGit Installation and Usage on Ubuntu

You can add a PPA that provides a relatively current version of SmartGit(as well as SmartGitHg, the predecessor of SmartGit).

To add the PPA run:

sudo add-apt-repository ppa:eugenesan/ppa
sudo apt-get update

To install smartgit (after adding the PPA) run:

sudo apt-get install smartgit

To install smartgithg (after adding the PPA) run:

sudo apt-get install smartgithg

This should add a menu option for you

For more information, see Eugene San PPA.

This repository contains collection of customized, updated, ported and backported packages for two last LTS releases and latest pre-LTS release

Abstract methods in Python

You have to implement an abstract base class (ABC).

Check python docs

Custom height Bootstrap's navbar

For Bootstrap 4, there are now spacing utilities so it's easier to change the height via padding on the nav links. This can be responsively applied only at specific breakpoints (ie: py-md-3). For example, on larger (md) screens, this nav is 120px high, then shrinks to normal height for the mobile menu. No extra CSS is needed..

<nav class="navbar navbar-fixed-top navbar-inverse bg-primary navbar-toggleable-md py-md-3">
    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNav" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    <a class="navbar-brand" href="#">Brand</a>
    <div class="navbar-collapse collapse" id="navbarNav">
        <ul class="navbar-nav">
            <li class="nav-item py-md-3"><a href="#" class="nav-link">Home</a></li>
            <li class="nav-item py-md-3"><a href="#" class="nav-link">Link</a></li>
            <li class="nav-item py-md-3"><a href="#" class="nav-link">Link</a></li>
            <li class="nav-item py-md-3"><a href="#" class="nav-link">More</a></li>
            <li class="nav-item py-md-3"><a href="#" class="nav-link">Options</a></li>

Bootstrap 4 Navbar Height Demo

PostgreSQL how to see which queries have run

You can see in pg_log folder if the log configuration is enabled in postgresql.conf with this log directory name.

How can I use onItemSelected in Android?

You're almost there. As you can see, the onItemSelected will give you a position parameter, you can use this to retrieve the object from your adapter, as in getItemAtPosition(position).




public void onItemSelected(AdapterView<?> parent, View view, int pos,long id) {
        "OnItemSelectedListener : " + parent.getItemAtPosition(pos).toString(),

This will put a message on screen, with the selected item printed by its toString() method.

cat, grep and cut - translated to python

In Python, without external dependencies, it is something like this (untested):

with open("filename") as origin:
    for line in origin:
        if not "something" in line:
            print line.split('"')[1]
        except IndexError:

Pass a JavaScript function as parameter

You just need to remove the parenthesis:

addContact(entityId, refreshContactList);

This then passes the function without executing it first.

Here is an example:

function addContact(id, refreshCallback) {
    // You can also pass arguments if you need to
    // refreshCallback(id);

function refreshContactList() {
    alert('Hello World');

addContact(1, refreshContactList);

C# winforms combobox dynamic autocomplete

In previous replies are drawbacks. Offers its own version with the selection in the drop down list the desired item:

    private ConnectSqlForm()
        cmbDatabases.TextChanged += UpdateAutoCompleteComboBox;
        cmbDatabases.KeyDown += AutoCompleteComboBoxKeyPress;

    private void UpdateAutoCompleteComboBox(object sender, EventArgs e)
        var comboBox = sender as ComboBox;
        if(comboBox == null)
        string txt = comboBox.Text;
        string foundItem = String.Empty;
        foreach(string item in comboBox.Items)
            if (!String.IsNullOrEmpty(txt) && item.ToLower().StartsWith(txt.ToLower()))
                foundItem = item;

        if (!String.IsNullOrEmpty(foundItem))
            if (String.IsNullOrEmpty(txt) || !txt.Equals(foundItem))
                comboBox.TextChanged -= UpdateAutoCompleteComboBox;
                comboBox.Text = foundItem;
                comboBox.DroppedDown = true;
                Cursor.Current = Cursors.Default;
                comboBox.TextChanged += UpdateAutoCompleteComboBox;

            comboBox.SelectionStart = txt.Length;
            comboBox.SelectionLength = foundItem.Length - txt.Length;
            comboBox.DroppedDown = false;

    private void AutoCompleteComboBoxKeyPress(object sender, KeyEventArgs e)
        var comboBox = sender as ComboBox;
        if (comboBox != null && comboBox.DroppedDown)
            switch (e.KeyCode)
                case Keys.Back:
                    int sStart = comboBox.SelectionStart;
                    if (sStart > 0)
                        comboBox.Text = sStart == 0 ? "" : comboBox.Text.Substring(0, sStart);
                    e.SuppressKeyPress = true;


How do I implement a callback in PHP?

I cringe every time I use create_function() in php.

Parameters are a coma separated string, the whole function body in a string... Argh... I think they could not have made it uglier even if they tried.

Unfortunately, it is the only choice when creating a named function is not worth the trouble.

Regular expression [Any number]

You can use the following function to find the biggest [number] in any string.

It returns the value of the biggest [number] as an Integer.

var biggestNumber = function(str) {
    var pattern = /\[([0-9]+)\]/g, match, biggest = 0;

    while ((match = pattern.exec(str)) !== null) {
        if (match.index === pattern.lastIndex) {
        match[1] = parseInt(match[1]);
        if(biggest < match[1]) {
            biggest = match[1];
    return biggest;


The following demo calculates the biggest number in your textarea every time you click the button.

It allows you to play around with the textarea and re-test the function with a different text.

var biggestNumber = function(str) {_x000D_
    var pattern = /\[([0-9]+)\]/g, match, biggest = 0;_x000D_
    while ((match = pattern.exec(str)) !== null) {_x000D_
        if (match.index === pattern.lastIndex) {_x000D_
        match[1] = parseInt(match[1]);_x000D_
        if(biggest < match[1]) {_x000D_
            biggest = match[1];_x000D_
    return biggest;_x000D_
document.getElementById("myButton").addEventListener("click", function() {_x000D_
    <textarea rows="6" cols="50" id="myTextArea">_x000D_
this is a test [1] also this [2] is a test_x000D_
and again [18] this is a test. _x000D_
items[14].items[29].firstname too is a test!_x000D_
items[4].firstname too is a test!_x000D_
   <button id="myButton">Try me</button>_x000D_

See also this Fiddle!

Failed loading english.pickle with

In Python-3.6 I can see the suggestion in the traceback. That's quite helpful. Hence I will say you guys to pay attention to the error you got, most of the time answers are within that problem ;).

enter image description here

And then as suggested by other folks here either using python terminal or using a command like python -c "import nltk;'wordnet')" we can install them on the fly. You just need to run that command once and then it will save the data locally in your home directory.

How to combine results of two queries into a single dataset

Try this:


$analyticsData = $this->user->getMemberInfoCurrentMonth($userId);
$analyticsData1 = $this->user->getMemberInfoLastMonth($userId);
$analyticsData2 = $this->user->getMemberInfAllTime($userId);                        

    foreach ($analyticsData2 as $arr) {                
        foreach ($analyticsData1 as $arr1) {
            if ($arr->fullname == $arr1->fullname) {
                $arr->last_send_count = $arr1->last_send_count;
                $arr->last_send_count = 0;
        foreach ($analyticsData as $arr2) {
            if ($arr->fullname == $arr2->fullname) {
                $arr->current_send_count = $arr2->current_send_count;
                $arr->current_send_count = 0;
    echo "<pre>";

Error in finding last used cell in Excel with VBA

I wonder that nobody has mentioned this, But the easiest way of getting the last used cell is:

Function GetLastCell(sh as Worksheet) As Range
    GetLastCell = sh.Cells(1,1).SpecialCells(xlLastCell)
End Function

This essentially returns the same cell that you get by Ctrl + End after selecting Cell A1.

A word of caution: Excel keeps track of the most bottom-right cell that was ever used in a worksheet. So if for example you enter something in B3 and something else in H8 and then later on delete the contents of H8, pressing Ctrl + End will still take you to H8 cell. The above function will have the same behavior.

How do I restore a dump file from mysqldump?

One-liner command to restore the generated SQL from mysqldump

mysql -u <username> -p<password> -e "source <path to sql file>;"

An error occurred while executing the command definition. See the inner exception for details

I've just run into this issue and it was because I had updated a view in my DB and not refreshed the schema in my mapping.

Project Links do not work on Wamp Server

How To Fix The Broken Icon Links (blank.gif, text.gif, etc.)

Unfortunately as previously mentioned, simply adding a virtual host to your project doesn't fix the broken icon links.

The Problem:

WAMP/Apache does not change the directory reference for the icons to your respective installation directory. It is statically set to "c:/Apache24/icons" and 99.9% of users Apache installation does not reside here. Especially with WAMP.

The Fix:

  1. Find your Apache icons directory! Typically it will be located here: "c:/wamp/bin/apache/apache2.4.9/icons". However your mileage may vary depending on your installation and if your Apache version is different, then your path will be different as well.\

  2. Open up httpd-autoindex.conf in your favorite editor. This file can usually be found here: "C:\wamp\bin\apache\apache2.4.9\conf\extra\httpd-autoindex.conf". Again, if your Apache version is different, then so will this path.

  3. Find this definition (usually located near the top of the file):

    Alias /icons/ "c:/Apache24/icons/"
    <Directory "c:/Apache24/icons">
    Options Indexes MultiViews
    AllowOverride None
    Require all granted
  4. Replace the "c:/Apache24/icons/" directories with your own. IMPORTANT You MUST have a trailing forward slash in the first directory reference. The second directory reference must have no trailing slash. Your results should look similar to this. Again, your directory may differ:

    Alias /icons/ "c:/wamp/bin/apache/apache2.4.9/icons/"
    <Directory "c:/wamp/bin/apache/apache2.4.9/icons">
    Options Indexes MultiViews
    AllowOverride None
    Require all granted
  5. Restart your Apache server and enjoy your cool icons!

What is the best way to search the Long datatype within an Oracle database?


create table longtable(id number,text long);

insert into longtable values(1,'hello world');
insert into longtable values(2,'say hello!');


create or replace function search_long(r rowid) return varchar2 is
temporary_varchar varchar2(4000);
select text into temporary_varchar from longtable where rowid=r;
return temporary_varchar;

SQL> select text from longtable where search_long(rowid) like '%hello%';                                                                              

hello world
say hello!

But be careful. A PL/SQL function will only search the first 32K of LONG.

How do I get ASP.NET Web API to return JSON instead of XML using Chrome?

I found the Chrome app "Advanced REST Client" excellent to work with REST services. You can set the Content-Type to application/json among other things: Advanced REST client

Use querystring variables in MVC controller

I figured it out...finally found another article on it.

string start = Request.QueryString["start"];

string end = Request.QueryString["end"];

Update just one gem with bundler

I've used bundle update --source myself for a long time but there are scenarios where it doesn't work. Luckily, there's a gem called bundler-patch which has the goal of fixing this shortcoming.

I also wrote a short blog post about how to use bundler-patch and why bundle update --source doesn't work consistently. Also, be sure to check out a post by chrismo that explains in great detail what the --source option does.

MAMP mysql server won't start. No mysql processes are running

Ok, so I tried EVERY suggestion i found here on SO and other forums I nothing worked for me. The only solution, that worked for me was to install MAMP 3 version, since I use MAMP for wordpress projects version 3 works just fine.

How to remove components created with Angular-CLI

I had the same issue, couldn't find a right solution so I have manually deleted the component folder and then updated the app.module.ts file (removed the references to the deleted component) and it worked for me.

Warning: #1265 Data truncated for column 'pdd' at row 1

You are most likely pushing a string 'NULL' to the table, rather then an actual NULL, but other things may be going on as well, an illustration:

mysql> CREATE TABLE date_test (pdd DATE NOT NULL);
Query OK, 0 rows affected (0.11 sec)

mysql> INSERT INTO date_test VALUES (NULL);
ERROR 1048 (23000): Column 'pdd' cannot be null
mysql> INSERT INTO date_test VALUES ('NULL');
Query OK, 1 row affected, 1 warning (0.05 sec)

mysql> show warnings;
| Level   | Code | Message                                  |
| Warning | 1265 | Data truncated for column 'pdd' at row 1 |
1 row in set (0.00 sec)

mysql> SELECT * FROM date_test;
| pdd        |
| 0000-00-00 |
1 row in set (0.00 sec)

Query OK, 1 row affected (0.15 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> INSERT INTO date_test VALUES (NULL);
Query OK, 1 row affected (0.06 sec)

mysql> SELECT * FROM date_test;
| pdd        |
| 0000-00-00 |
| NULL       |
2 rows in set (0.00 sec)

What does "javascript:void(0)" mean?

void is an operator that is used to return a undefined value so the browser will not be able to load a new page.

Web browsers will try and take whatever is used as a URL and load it unless it is a JavaScript function that returns null. For example, if we click a link like this:

<a href="javascript: alert('Hello World')">Click Me</a>

then an alert message will show up without loading a new page, and that is because alert is a function that returns a null value. This means that when the browser attempts to load a new page it sees null and has nothing to load.

An important thing to note about the void operator is that it requires a value and cannot be used by itself. We should use it like this:

<a href="javascript: void(0)">I am a useless link</a>

SQL Server: Query fast, but slow from procedure

Do this for your database. I have the same issue - it works fine in one database but when I copy this database to another using SSIS Import (not the usual restore), this issue happens to most of my stored procedures. So after googling some more, I found the blog of Pinal Dave (which btw, I encountered most of his post and did help me a lot so thanks Pinal Dave).

I execute the below query on my database and it corrected my issue:

EXEC sp_MSforeachtable @command1="print '?' DBCC DBREINDEX ('?', ' ', 80)"
EXEC sp_updatestats

Hope this helps. Just passing the help from others that helped me.

Convert to absolute value in Objective-C

Depending on the type of your variable, one of abs(int), labs(long), llabs(long long), imaxabs(intmax_t), fabsf(float), fabs(double), or fabsl(long double).

Those functions are all part of the C standard library, and so are present both in Objective-C and plain C (and are generally available in C++ programs too.)

(Alas, there is no habs(short) function. Or scabs(signed char) for that matter...)

Apple's and GNU's Objective-C headers also include an ABS() macro which is type-agnostic. I don't recommend using ABS() however as it is not guaranteed to be side-effect-safe. For instance, ABS(a++) will have an undefined result.

If you're using C++ or Objective-C++, you can bring in the <cmath> header and use std::abs(), which is templated for all the standard integer and floating-point types.

Can't use Swift classes inside Objective-C

well, after reading all the comments and trying and reading and trying again, I managed to include swift classes into my Big obj-c project. So, thanks for all the help. I wanted to share one tip that helped me understand the process better. In the .m class, went to the import line of the swift target name #import "myTargetName-Swift.h" and clicked the key:

command + mouse click -> Jump to definition enter image description here

There you can see all the translation from swift to obj-c and ther you will find the various functions re-declared in obj-c. Hope this tip will help you as much as it helped me.

How do you round UP a number in Python?

when you operate 4500/1000 in python, result will be 4, because for default python asume as integer the result, logically: 4500/1000 = 4.5 --> int(4.5) = 4 and ceil of 4 obviouslly is 4

using 4500/1000.0 the result will be 4.5 and ceil of 4.5 --> 5

Using javascript you will recieve 4.5 as result of 4500/1000, because javascript asume only the result as "numeric type" and return a result directly as float

Good Luck!!

Scroll to bottom of div with Vue.js

2021 easy solution that won't hurt your brain... use el.scrollIntoView()

Here is a fiddle.

This solution will not hurt your brain having to think about scrollTop or scrollHeight, has smooth scrolling built in, and even works in IE.

scrollIntoView() has options you can pass it like scrollIntoView({behavior: 'smooth'}) to get smooth scrolling.

methods: {
  scrollToElement() {
    const el = this.$el.getElementsByClassName('scroll-to-me')[0];

    if (el) {
      // Use el.scrollIntoView() to instantly scroll to the element
      el.scrollIntoView({behavior: 'smooth'});

Then if you wanted to scroll to this element on page load you could call this method like this:

mounted() {

Else if you wanted to scroll to it on a button click or some other action you could call it the same way:

<button @click="scrollToElement">scroll to me</button>

The scroll works all the way down to IE 8. The smooth scroll effect does not work out of the box in IE or Safari. If needed there is a polyfill available for this here as @mostafaznv mentioned in the comments.

Loading a properties file from Java package

Nobody mentions the similar but even simpler solution than above with no need to deal with the package of the class. Assuming is in the classpath.

        Properties properties = new Properties();
        InputStream in = ClassLoader.getSystemResourceAsStream("");


How can I get the MAC and the IP address of a connected client in PHP?

We can get MAC address in Ubuntu by this ways in php

$ipconfig =   shell_exec ("ifconfig -a | grep -Po 'HWaddr \K.*$'");  
    // display mac address   
 echo $ipconfig;

Using Predicate in Swift

In swift 2.2

func filterContentForSearchText(searchText: String, scope: String) {
    var resultPredicate = NSPredicate(format: "name contains[c]         %@", searchText)
    searchResults = (recipes as NSArray).filteredArrayUsingPredicate(resultPredicate)

In swift 3.0

func filterContent(forSearchText searchText: String, scope: String) {
        var resultPredicate = NSPredicate(format: "name contains[c]         %@", searchText)
        searchResults = recipes.filtered(using: resultPredicate)

What does the "undefined reference to varName" in C mean?

make sure your doSomething function is not static.

WCF named pipe minimal example

Try this.

Here is the service part.

public interface IService
    void  HelloWorld();

public class Service : IService
    public void HelloWorld()
        //Hello World

Here is the Proxy

public class ServiceProxy : ClientBase<IService>
    public ServiceProxy()
        : base(new ServiceEndpoint(ContractDescription.GetContract(typeof(IService)),
            new NetNamedPipeBinding(), new EndpointAddress("net.pipe://localhost/MyAppNameThatNobodyElseWillUse/helloservice")))

    public void InvokeHelloWorld()

And here is the service hosting part.

var serviceHost = new ServiceHost
        (typeof(Service), new Uri[] { new Uri("net.pipe://localhost/MyAppNameThatNobodyElseWillUse") });
    serviceHost.AddServiceEndpoint(typeof(IService), new NetNamedPipeBinding(), "helloservice");

    Console.WriteLine("Service started. Available in following endpoints");
    foreach (var serviceEndpoint in serviceHost.Description.Endpoints)

How to cast Object to boolean?

Assuming that yourObject.toString() returns "true" or "false", you can try

boolean b = Boolean.valueOf(yourObject.toString())

How do I edit $PATH (.bash_profile) on OSX?

A bit more detailed for beginners:

Before you begin with .bash_profile on Mac, please be aware that since macOS Catalina zsh (z shell) is the default shell. Therefore stuff we used to put in the .bash_profile now belongs to the .zshenv or the .zshrc file.

.zshenv .zshrc ? (Found here)

.zshenv: invocations of the shell. Often contains exported variables that should be available to other programs. For example, $PATH.

.zshrc: Sourced in interactive shells only. It should contain commands to set up aliases, functions, options, key bindings, etc.


Make sure the .bash_profile file is existing? (or the .zshenv of course) Remember that the .bash_profile file isn't there by default. You have to create it on your own.

Go into your user folder in finder. The .bash_profile file should be findable there. -> HD/Users/[USERNAME]

Remember: Files with a point at the beginning '.' are hidden by default.

To show hidden files in Mac OS Finder:

Press: Command + Shift + .

If it's not existing, you have to create .bash_profile on your own.

Open terminal app and switch into user folder with simple command:


If it's not existing, use this command to create the file:

touch .bash_profile


If you can't memorise the nerdy commands for save and close in vim, nano etc (the way recommended above) the easiest way to edit is to open .bash_profile (or the .zshenv) file in your favored code editor (Sublime, Visual Studio Code, etc.).

Finder -> User folder. Right click -> open with : Visual Studio Code (or other code editor). Or drag it on app in dock.

… and there you can edit it, pass export commands in new lines.

Why would I use dirname(__FILE__) in an include or include_once statement?

Let's say I have a (fake) directory structure like:


Now assume that bootstrap.php has some code included for setting up database connections or some other kind of boostrapping stuff.

Assume you want to include a file in boostrap.php's folder called init.php. Now, to avoid scanning the entire include path with include 'init.php', you could use include './init.php'.

There's a problem though. That ./ will be relative to the script that included bootstrap.php, not bootstrap.php. (Technically speaking, it will be relative to the working directory.)

dirname(__FILE__) allows you to get an absolute path (and thus avoid an include path search) without relying on the working directory being the directory in which bootstrap.php resides.

(Note: since PHP 5.3, you can use __DIR__ in place of dirname(__FILE__).)

Now, why not just use include 'init.php';?

As odd as it is at first though, . is not guaranteed to be in the include path. Sometimes to avoid useless stat()'s people remove it from the include path when they are rarely include files in the same directory (why search the current directory when you know includes are never going to be there?).

Note: About half of this answer is address in a rather old post: What's better of require(dirname(__FILE__).'/'.'myParent.php') than just require('myParent.php')?

CSS /JS to prevent dragging of ghost image?

You can use "Empty Img Element".
Empty Img Element - document.createElement("img")

[HTML Code]
<div id="hello" draggable="true">Drag!!!</div>
[JavaScript Code]
var block = document.querySelector('#hello');
block.addEventListener('dragstart', function(e){
    var img = document.createElement("img");
    e.dataTransfer.setDragImage(img, 0, 0);

How do I install opencv using pip?

You could try using below command-

pip install opencv-contrib-python

It will basically download the compatible version. If this command fails, you could upgrade you pip using below command-

python -m pip install –upgrade pip

If you need a pictorial guide, head over to Simple Steps to Install OpenCV in Windows

You can also try installing OpenCV from prebuilt binaries from the official OpenCV site.

How to detect window.print() finish

Print in new window with w =, '_blank') and try w.focus();w.close(); and detect when page is closed. Works in all browsers.

w =, '_blank');
w.onunload = function(){

Window close after finish print.

Trim spaces from end of a NSString

NSString* NSStringWithoutSpace(NSString* string)
    return [string stringByReplacingOccurrencesOfString:@" " withString:@""];

HTML: can I display button text in multiple lines?

You can break a text using an entity in between the value. See the entity in example below:

<input style="width:100px;" type="button" value="Click here &#x00A; to &#x00A; start playing">

@RequestBody and @ResponseBody annotations in Spring

package com.programmingfree.springshop.controller;

import java.util.List;

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.programmingfree.springshop.dao.UserShop;
import com.programmingfree.springshop.domain.User;

public class SpringShopController {

 UserShop userShop=new UserShop();

 @RequestMapping(value = "/{id}", method = RequestMethod.GET,headers="Accept=application/json")
 public User getUser(@PathVariable int id) {
  User user=userShop.getUserById(id);
  return user;

 @RequestMapping(method = RequestMethod.GET,headers="Accept=application/json")
 public List<User> getAllUsers() {
  List<User> users=userShop.getAllUsers();
  return users;


In the above example they going to display all user and particular id details now I want to use both id and name,

1) localhost:8093/plejson/shop/user <---this link will display all user details
2) localhost:8093/plejson/shop/user/11 <----if i use 11 in link means, it will display particular user 11 details

now I want to use both id and name

localhost:8093/plejson/shop/user/11/raju <-----------------like this it means we can use any one in this please help me out.....

Insert Data Into Temp Table with Query

Personally, I needed a little hand holding figuring out how to use this and it is really, awesome.

        SELECT *
            INTO #TEMP
            FROM (
            The query you want to use many times
            ) AS X



Angularjs on page load call function

It's not the angular way, remove the function from html body and use it in controller, or use


More details are available here:

Add a "sort" to a =QUERY statement in Google Spreadsheets

Sorting by C and D needs to be put into number form for the corresponding column, ie 3 and 4, respectively. Eg Order By 2 asc")

No increment operator (++) in Ruby?

I don't think that notation is available because—unlike say PHP or C—everything in Ruby is an object.

Sure you could use $var=0; $var++ in PHP, but that's because it's a variable and not an object. Therefore, $var = new stdClass(); $var++ would probably throw an error.

I'm not a Ruby or RoR programmer, so I'm sure someone can verify the above or rectify it if it's inaccurate.

Creating pdf files at runtime in c#

Well, free and not-for-free, I use WebSuperGoo ABCpdf .NET component, that I just love it!

not-for-free because you need to pay for it.

for free because even if you have to pay, they have a trial version and you can request a free license if you do not mind that, in your site show "This site uses WebSuperGoo ABCpdf .NET component" with a link to their website.

I did that and I got a free license (version 5 in that time) so, I can say that it works (even if the website is no longer online) - I still have and use the component ~:)

A wonderful thing that I love with this is that you can do everything that you can thing off with this, create PDF forms and dynamically fill them and send to user by mail or have them to download it, create a pdf from scratch, convert HTML pages into PDF, etc etc etc, please read the documentation, it is a wonderful component.

Is there a Google Sheets formula to put the name of the sheet into a cell?

An old thread, but a useful one... so here's some additional code.

First, in response to Craig's point about the regex being overly greedy and failing for sheet names containing a single quote, this should do the trick (replace 'SHEETNAME'!A1 with your own sheet & cell reference):

=IF(TODAY()=TODAY(), SUBSTITUTE(REGEXREPLACE(CELL("address",'SHEETNAME'!A1),"'?(.+?)'?!\$.*","$1"),"''","'", ""), "")

It uses a lazy match (the ".+?") to find a character string (squotes included) that may or may not be enclosed by squotes but is definitely terminated by bang dollar ("!$") followed by any number of characters. Google Sheets actually protects squotes within a sheet name by appending another squote (as in ''), so the SUBSTITUTE is needed to reduce these back to single squotes.

The formula also allows for sheet names that contain bangs ("!"), but will fail for names using bang dollars ("!$") - if you really need to make your sheet names to look like full absolute cell references then put a separating character between the bang and the dollar (such as a space).

Note that it will only work correctly when pointed at a different sheet from the one that the formula resides! This is because CELL("address" returns just the cell reference (not the sheet name) when used on the same sheet. If you need a sheet to show its own name then put the formula in a cell on another sheet, point it at your target sheet, and then reference the formula cell from the target sheet. I often have a "Meta" sheet in my workbooks to hold settings, common values, database matching criteria, etc so that's also where I put this formula.

As others have said many times above, Google Sheets will only notice changes to the sheet name if you set the workbook's recalculation to "On change and every minute" which you can find on the File|Settings|Calculation menu. It can take up to a whole minute for the change to be picked up.

Secondly, if like me you happen to need an inter-operable formula that works on both Google Sheets and Excel (which for older versions at least doesn't have the REGEXREPLACE function), try:

=IF(IFERROR(INFO("release"), 0)=0, IF(TODAY()=TODAY(), SUBSTITUTE(REGEXREPLACE(CELL("address",'SHEETNAME'!A1),"'?(.+?)'?!\$.*","$1"),"''","'", ""), ""), MID(CELL("filename",'SHEETNAME'!A1),FIND("]",CELL("filename",'SHEETNAME'!A1))+1,255))

This uses INFO("release") to determine which platform we are on... Excel returns a number >0 whereas Google Sheets does not implement the INFO function and generates an error which the formula traps into a 0 and uses for numerical comparison. The Google code branch is as above.

For clarity and completeness, this is the Excel-only version (which does correctly return the name of the sheet it resides on):


It looks for the "]" filename terminator in the output of CELL("filename" and extracts the sheet name from the remaining part of the string using the MID function. Excel doesn't allow sheet names to contain "]" so this works for all possible sheet names. In the inter-operable version, Excel is happy to be fed a call to the non-existent REGEXREPLACE function because it never gets to execute the Google code branch.

Makefile - missing separator

You need to precede the lines starting with gcc and rm with a hard tab. Commands in make rules are required to start with a tab (unless they follow a semicolon on the same line). The result should look like this:

PROG = semsearch
all: $(PROG)
%: %.c
        gcc -o $@ $< -lpthread

        rm $(PROG)

Note that some editors may be configured to insert a sequence of spaces instead of a hard tab. If there are spaces at the start of these lines you'll also see the "missing separator" error. If you do have problems inserting hard tabs, use the semicolon way:

PROG = semsearch
all: $(PROG)
%: %.c ; gcc -o $@ $< -lpthread

clean: ; rm $(PROG)

Dropdown using javascript onchange

It does not work because your script in JSFiddle is running inside it's own scope (see the "OnLoad" drop down on the left?).

One way around this is to bind your event handler in javascript (where it should be):

document.getElementById('optionID').onchange = function () {
    document.getElementById("message").innerHTML = "Having a Baby!!";

Another way is to modify your code for the fiddle environment and explicitly declare your function as global so it can be found by your inline event handler:

window.changeMessage() {
    document.getElementById("message").innerHTML = "Having a Baby!!";


Haskell: Converting Int to String

Anyone who is just starting with Haskell and trying to print an Int, use:

module Lib
    ( someFunc
    ) where

someFunc :: IO ()
x = 123
someFunc = putStrLn (show x)

Which comes first in a 2D array, rows or columns?

Java is considered "row major", meaning that it does rows first. This is because a 2D array is an "array of arrays".

For example:

int[ ][ ] a = new int[2][4];  // Two rows and four columns.

a[0][0] a[0][1] a[0][2] a[0][3]

a[1][0] a[1][1] a[1][2] a[1][3]

It can also be visualized more like this:

a[0] ->  [0] [1] [2] [3]
a[1] ->  [0] [1] [2] [3]

The second illustration shows the "array of arrays" aspect. The first array contains {a[0] and a[1]}, and each of those is an array containing four elements, {[0][1][2][3]}.

TL;DR summary:

Array[number of arrays][how many elements in each of those arrays]

For more explanations, see also Arrays - 2-dimensional.

center image in div with overflow hidden

I have been trying to implement Jaap's answer inside this page of my recent site, with one difference : the .main {height:} was set to auto instead of a fixed px value. As responsive developer i am looking for a solution to synchronize the image height with the left floating text element, yet only in case my text height becomes greater then my actual image height. In that case the image should not be rescaled, but cropped and centered as decribed in the original question here above. Can this be done ? You can simulate the behaviour by slowly downsizing the browser's width.

Javascript logical "!==" operator?

You can find === and !== operators in several other dynamically-typed languages as well. It always means that the two values are not only compared by their "implied" value (i.e. either or both values might get converted to make them comparable), but also by their original type.

That basically means that if 0 == "0" returns true, 0 === "0" will return false because you are comparing a number and a string. Similarly, while 0 != "0" returns false, 0 !== "0" returns true.

Add custom buttons on Slick Carousel

Why you cant use default CSS classes and add some your style?

.slick-next {
  /*my style*/
  background: url(my-image.png);


.slick-prev {
  /*my style*/
  background: url(my-image.png);

Are you used simple background css property?

in example:

You can use Font Awesome too. Don't forget about CSS pseudo elements.

And don't forget jQuery, you can replace elements, add classes, etc.

Windows command for file size only

Taken from here:

The following command finds folders that are greater than 100 MB in size on the D: drive:

diruse /s /m /q:100 /d d:

The /s option causes subdirectories to be searched, the /m option displays disk usage in megabytes, the /q:100 option causes folders that are greater than 100 MB to be marked, and the /d option displays only folders that exceed the threshold specified by /q.

Use the diskuse command to find files over a certain size. The following command displays files over 100 MB in size on the D: drive:

diskuse D: /x:104857600 /v /s

The /x:104857600 option causes files over 104,857,600 bytes to be displayed and is valid only if you include the /v option (verbose). The /s option means subdirectories from the specified path (in this case, the D: drive) are searched.

Using VBScript

' This code finds all files over a certain size.
strComputer = "**<ServerName>**" 
intSizeBytes = 1024 * 1024 * 500  ' = 500 MB
' ------ END CONFIGURATION ---------
set objWMI = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
set colFiles = objWMI.ExecQuery _
    ("Select * from CIM_DataFile where FileSize > '" & intSizeBytes & "'")
for each objFile in colFiles
    Wscript.Echo objFile.Name & "  " & objFile.Filesize / 1024 / 1024 & "MB"

How can I split a string into segments of n characters?

Building on the previous answers to this question; the following function will split a string (str) n-number (size) of characters.

function chunk(str, size) {
    return str.match(new RegExp('.{1,' + size + '}', 'g'));


(function() {_x000D_
  function chunk(str, size) {_x000D_
    return str.match(new RegExp('.{1,' + size + '}', 'g'));_x000D_
  var str = 'HELLO WORLD';_x000D_
  println('Simple binary representation:');_x000D_
  println(chunk(textToBin(str), 8).join('\n'));_x000D_
  println('\nNow for something crazy:');_x000D_
  println(chunk(textToHex(str, 4), 8).map(function(h) { return '0x' + h }).join('  '));_x000D_
  // Utiliy functions, you can ignore these._x000D_
  function textToBin(text) { return textToBase(text, 2, 8); }_x000D_
  function textToHex(t, w) { return pad(textToBase(t,16,2), roundUp(t.length, w)*2, '00'); }_x000D_
  function pad(val, len, chr) { return (repeat(chr, len) + val).slice(-len); }_x000D_
  function print(text) { document.getElementById('out').innerHTML += (text || ''); }_x000D_
  function println(text) { print((text || '') + '\n'); }_x000D_
  function repeat(chr, n) { return new Array(n + 1).join(chr); }_x000D_
  function textToBase(text, radix, n) {_x000D_
    return text.split('').reduce(function(result, chr) {_x000D_
      return result + pad(chr.charCodeAt(0).toString(radix), n, '0');_x000D_
    }, '');_x000D_
  function roundUp(numToRound, multiple) { _x000D_
    if (multiple === 0) return numToRound;_x000D_
    var remainder = numToRound % multiple;_x000D_
    return remainder === 0 ? numToRound : numToRound + multiple - remainder;_x000D_
#out {_x000D_
  white-space: pre;_x000D_
  font-size: 0.8em;_x000D_
<div id="out"></div>

Asking the user for input until they give a valid response

While a try/except block will work, a much faster and cleaner way to accomplish this task would be to use str.isdigit().

while True:
    age = input("Please enter your age: ")
    if age.isdigit():
        age = int(age)
        print("Invalid number '{age}'. Try again.".format(age=age))

if age >= 18: 
    print("You are able to vote in the United States!")
    print("You are not able to vote in the United States.")

Angular 2 router.navigate

If the first segment doesn't start with / it is a relative route. router.navigate needs a relativeTo parameter for relative navigation

Either you make the route absolute:

this.router.navigate(['/foo-content', 'bar-contents', 'baz-content', 'page'], this.params.queryParams)

or you pass relativeTo

this.router.navigate(['../foo-content', 'bar-contents', 'baz-content', 'page'], {queryParams: this.params.queryParams, relativeTo: this.currentActivatedRoute})

See also

convert float into varchar in SQL server without scientific notation

I have another solution since the STR() function would result some blank spaces, so I use the FORMAT() function as folowing example:

SELECT ':' + STR(1000.2324422), ':' + FORMAT(1000.2324422,'##.#######'), ':' + FORMAT(1000.2324422,'##')

The result of above code would be:

:      1000 :1000.2324422   :1000

Generate random number between two numbers in JavaScript


Return a random number between 1 and 10:

Math.floor((Math.random() * 10) + 1);

The result could be: 3

Try yourself: here


or using lodash / undescore:

_.random(min, max)

Docs: - lodash - undescore

Can I export a variable to the environment from a bash script without sourcing it?

I don't think this can be done but I found a workaround using alias. It will only work when you place your script in your scripts directory, otherwise your alias will have an invalid name. The only point to the work around is to be able to have a function inside a file with the same name and not have to bother sourcing it before using it. Add the following code to ~/.bashrc:

alias myFunction='unalias myFunction && . myFunction && myFunction "$@"'

You can now call myFunction without sourcing it first.

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

Angular 9 approach:

constructor() {
    window.addEventListener('beforeunload', (event: BeforeUnloadEvent) => {
     if (this.generatedBarcodeIndex) {
      event.preventDefault(); // for Firefox
      event.returnValue = ''; // for Chrome
      return '';
     return false;

Browsers support and the removal of the custom message:

  • Chrome removed support for the custom message in ver 51 min
  • Opera removed support for the custom message in ver 38 min
  • Firefox removed support for the custom message in ver 44.0 min
  • Safari removed support for the custom message in ver 9.1 min

SVN Error - Not a working copy

Had this same problem, turns out we had Slik 1.6.2 as well as Tortoise on the same machine. Tortoise had been updated (and had updated the working copy) but Slik had not, so Tortoise worked OK, but command lines failed with:

svn: '.' is not a working copy directory

Removing both Tortoise and Slik, then reinstalling Tortoise with command line tools enabled fixed this for me.

How to start an application without waiting in a batch file?

I'm making a guess here, but your start invocation probably looks like this:

start "\Foo\Bar\Path with spaces in it\program.exe"

This will open a new console window, using “\Foo\Bar\Path with spaces in it\program.exe” as its title.

If you use start with something that is (or needs to be) surrounded by quotes, you need to put empty quotes as the first argument:

start "" "\Foo\Bar\Path with spaces in it\program.exe"

This is because start interprets the first quoted argument it finds as the window title for a new console window.

Where do I download JDBC drivers for DB2 that are compatible with JDK 1.5?

you can download and install db2client and looking for - db2jcc.jar - db2jcc_license_cisuz.jar - db2jcc_license_cu.jar - and etc. at C:\Program Files (x86)\IBM\SQLLIB\java

Django TemplateDoesNotExist?

Check that your templates.html are in /usr/lib/python2.5/site-packages/projectname/templates dir.

Why use deflate instead of gzip for text files served by Apache?

Why use deflate instead of gzip for text files served by Apache?

The simple answer is don't.

RFC 2616 defines deflate as:

deflate The "zlib" format defined in RFC 1950 in combination with the "deflate" compression mechanism described in RFC 1951

The zlib format is defined in RFC 1950 as :

     0   1
     |CMF|FLG|   (more-->)

       0   1   2   3
     |     DICTID    |   (more-->)

     |...compressed data...|    ADLER32    |

So, a few headers and an ADLER32 checksum

RFC 2616 defines gzip as:

gzip An encoding format produced by the file compression program "gzip" (GNU zip) as described in RFC 1952 [25]. This format is a Lempel-Ziv coding (LZ77) with a 32 bit CRC.

RFC 1952 defines the compressed data as:

The format presently uses the DEFLATE method of compression but can be easily extended to use other compression methods.

CRC-32 is slower than ADLER32

Compared to a cyclic redundancy check of the same length, it trades reliability for speed (preferring the latter).

So ... we have 2 compression mechanisms that use the same algorithm for compression, but a different algorithm for headers and checksum.

Now, the underlying TCP packets are already pretty reliable, so the issue here is not Adler 32 vs CRC-32 that GZIP uses.

Turns out many browsers over the years implemented an incorrect deflate algorithm. Instead of expecting the zlib header in RFC 1950 they simply expected the compressed payload. Similarly various web servers made the same mistake.

So, over the years browsers started implementing a fuzzy logic deflate implementation, they try for zlib header and adler checksum, if that fails they try for payload.

The result of having complex logic like that is that it is often broken. Verve Studio have a user contributed test section that show how bad the situation is.

For example: deflate works in Safari 4.0 but is broken in Safari 5.1, it also always has issues on IE.

So, best thing to do is avoid deflate altogether, the minor speed boost (due to adler 32) is not worth the risk of broken payloads.

Java 8 - Difference between Optional.flatMap and

Note:- below is the illustration of map and flatmap function, otherwise Optional is primarily designed to be used as a return type only.

As you already may know Optional is a kind of container which may or may not contain a single object, so it can be used wherever you anticipate a null value(You may never see NPE if use Optional properly). For example if you have a method which expects a person object which may be nullable you may want to write the method something like this:

void doSome(Optional<Person> person){
  /*and here you want to retrieve some property phone out of person
    you may write something like this:
  Optional<String> phone =>p.getPhone());
class Person{
  private String phone;
  //setter, getters

Here you have returned a String type which is automatically wrapped in an Optional type.

If person class looked like this, i.e. phone is also Optional

class Person{
  private Optional<String> phone;

In this case invoking map function will wrap the returned value in Optional and yield something like:

//And you may want Optional<String> instead, here comes flatMap

void doSome(Optional<Person> person){
  Optional<String> phone = person.flatMap((p)->p.getPhone());

PS; Never call get method (if you need to) on an Optional without checking it with isPresent() unless you can't live without NullPointerExceptions.

Binding an Image in WPF MVVM

Displaying an Image in WPF is much easier than that. Try this:

<Image Source="{Binding DisplayedImagePath}" HorizontalAlignment="Left" 
    Margin="0,0,0,0" Name="image1" Stretch="Fill" VerticalAlignment="Bottom" 
    Grid.Row="8" Width="200"  Grid.ColumnSpan="2" />

And the property can just be a string:

public string DisplayedImage 
    get { return @"C:\Users\Public\Pictures\Sample Pictures\Chrysanthemum.jpg"; }

Although you really should add your images to a folder named Images in the root of your project and set their Build Action to Resource in the Properties Window in Visual Studio... you could then access them using this format:

public string DisplayedImage 
    get { return "/AssemblyName;component/Images/ImageName.jpg"; }


As a final tip... if you ever have a problem with a control not working as expected, simply type 'WPF', the name of that control and then the word 'class' into a search engine. In this case, you would have typed 'WPF Image Class'. The top result will always be MSDN and if you click on the link, you'll find out all about that control and most pages have code examples as well.

UPDATE 2 >>>

If you followed the examples from the link to MSDN and it's not working, then your problem is not the Image control. Using the string property that I suggested, try this:

    <Image Source="{Binding DisplayedImagePath}" />
    <TextBlock Text="{Binding DisplayedImagePath}" />

If you can't see the file path in the TextBlock, then you probably haven't set your DataContext to the instance of your view model. If you can see the text, then the problem is with your file path.

UPDATE 3 >>>

In .NET 4, the above Image.Source values would work. However, Microsoft made some horrible changes in .NET 4.5 that broke many different things and so in .NET 4.5, you'd need to use the full pack path like this:

<Image Source="pack://application:,,,/AssemblyName;component/Images/image_to_use.png">

For further information on pack URIs, please see the Pack URIs in WPF page on Microsoft Docs.

swift UITableView set rowHeight

As pointed out in comments, you cannot call cellForRowAtIndexPath inside heightForRowAtIndexPath.

What you can do is creating a template cell used to populate with your data and then compute its height. This cell doesn't participate to the table rendering, and it can be reused to calculate the height of each table cell.

Briefly, it consists of configuring the template cell with the data you want to display, make it resize accordingly to the content, and then read its height.

I have taken this code from a project I am working on - unfortunately it's in Objective C, I don't think you will have problems translating to swift

- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    static PostCommentCell *sizingCell = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sizingCell = [self.tblComments dequeueReusableCellWithIdentifier:POST_COMMENT_CELL_IDENTIFIER];

    sizingCell.comment = self.comments[indexPath.row];
    [sizingCell setNeedsLayout];
    [sizingCell layoutIfNeeded];

    CGSize size = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
    return size.height;

Regex pattern to match at least 1 number and 1 character in a string

And an idea with a negative check.

  • ^(?! at start look ahead if string does not
  • \d*$ contain only digits | or
  • [a-z]*$ contain only letters
  • [a-z\d]+$ matches one or more letters or digits until $ end.

Have a look at this regex101 demo

(the i flag turns on caseless matching: a-z matches a-zA-Z)

Git Clone from GitHub over https with two-factor authentication

1st: Get personal access token.
2nd: Put account & the token. Example is here:

$ git push
Username for '':            # Put your GitHub account name
Password for 'https://{USERNAME}': # Put your Personal access token

Link on how to create a personal access token:

Using bootstrap with bower

The css and js files are located within the package: bootstrap/docs/assets/


since v3 there is a dist folder in the package that contains all css, js and fonts.

Another option (if you just want to fetch single files) might be: pulldown. Configuration is extremely simple and you can easily add your own files/urls to the list.

Angular: Cannot Get /

The weird thing that I was experiencing was that I could make changes to the components in Visual Studio 2019 while the app was running and see my changes but, when I restarted the app, I got the Cannot Get / error. Instead of running IIS Express, I chose to run the app using Angular JS and the build window showed me that there was an error in app.component.ts. It turned out to be an extra } at the end of the file. Not sure how it got there but, when I removed it, the app works fine.

Get value of Span Text

The accepted answer is close... but no cigar!

Use textContent instead of innerHTML if you strictly want a string to be returned to you.

innerHTML can have the side effect of giving you a node element if there's other dom elements in there. textContent will guard against this possibility.

angularjs make a simple countdown

Please take a look at this example here. It is a simple example of a count up! Which I think you could easily modify to create a count down.

JavaScript code:

function AlbumCtrl($scope,$timeout) {
    $scope.counter = 0;
    $scope.onTimeout = function(){
        mytimeout = $timeout($scope.onTimeout,1000);
    var mytimeout = $timeout($scope.onTimeout,1000);

    $scope.stop = function(){

HTML markup:

<!doctype html>
<html ng-app>
    <script src=""></script>
    <script src=""></script>
<div ng-controller="AlbumCtrl">
    <button ng-click="stop()">Stop</button>    

How do I use dataReceived event of the SerialPort Port Object in C#?

Be aware that there are problems using .NET/C# and any COM port higher than COM9.

See: HOWTO: Specify Serial Ports Larger than COM9

There is a workaround in the format: "\\.\COM10" that is supported in the underlying CreateFile method, but .NET prevents using that workaround format; neither the SerialPort constructor nor the PortName property will allow a port name that begins with "\"

I've been struggling to get reliable communications to COM10 in C#/.NET. As an example, if I have a device on COM9 and COM10, traffic intended for COM10 goes to the device on COM9! If I remove the device on COM9, COM10 traffic goes to the device on COM10.

I still haven't figured how to use the handle returned by CreateFile to create a C#/.NET style SerialPort object, if I knew how to do that, then I think I could use COM10+ just fine from C#.

Node.js Error: connect ECONNREFUSED

Run server.js from a different command line and client.js from a different command line

git checkout all the files

If you are at the root of your working directory, you can do git checkout -- . to check-out all files in the current HEAD and replace your local files.

You can also do git reset --hard to reset your working directory and replace all changes (including the index).

When should I use the new keyword in C++?

If your variable is used only within the context of a single function, you're better off using a stack variable, i.e., Option 2. As others have said, you do not have to manage the lifetime of stack variables - they are constructed and destructed automatically. Also, allocating/deallocating a variable on the heap is slow by comparison. If your function is called often enough, you'll see a tremendous performance improvement if use stack variables versus heap variables.

That said, there are a couple of obvious instances where stack variables are insufficient.

If the stack variable has a large memory footprint, then you run the risk of overflowing the stack. By default, the stack size of each thread is 1 MB on Windows. It is unlikely that you'll create a stack variable that is 1 MB in size, but you have to keep in mind that stack utilization is cumulative. If your function calls a function which calls another function which calls another function which..., the stack variables in all of these functions take up space on the same stack. Recursive functions can run into this problem quickly, depending on how deep the recursion is. If this is a problem, you can increase the size of the stack (not recommended) or allocate the variable on the heap using the new operator (recommended).

The other, more likely condition is that your variable needs to "live" beyond the scope of your function. In this case, you'd allocate the variable on the heap so that it can be reached outside the scope of any given function.

SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch

My 5 cents on the issue:

I had same problem. After about 1 hour looking after it, I found I pasted the certificate incorrectly.

If you have error like this, please check your certificate.

error LNK2005: xxx already defined in MSVCRT.lib(MSVCR100.dll) C:\something\LIBCMT.lib(setlocal.obj)

If you VS solution contains several projects, select all of them in the right pane, and press "properties". Then go to C++ -> Code Generation and chose one Run Time library option for all of them

crudrepository findBy method signature with multiple in operators?

The following signature will do:

List<Email> findByEmailIdInAndPincodeIn(List<String> emails, List<String> pinCodes);

Spring Data JPA supports a large number of keywords to build a query. IN and AND are among them.

How to Exit a Method without Exiting the Program?

If the function is a void, ending the function will return. Otherwise, you need to do an explicit return someValue. As Mark mentioned, you can also throw an exception. What's the context of your question? Do you have a larger code sample with which to show you some ways to exit the function?

Storyboard - refer to ViewController in AppDelegate

If you use XCode 5 you should do it in a different way.

  • Select your UIViewController in UIStoryboard
  • Go to the Identity Inspector on the right top pane
  • Check the Use Storyboard ID checkbox
  • Write a unique id to the Storyboard ID field

Then write your code.

// Override point for customization after application launch.

if (<your implementation>) {
    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" 
                                                             bundle: nil];
    YourViewController *yourController = (YourViewController *)[mainStoryboard 
    self.window.rootViewController = yourController;

return YES;

Set Matplotlib colorbar size to match graph

When you create the colorbar try using the fraction and/or shrink parameters.

From the documents:

fraction 0.15; fraction of original axes to use for colorbar

shrink 1.0; fraction by which to shrink the colorbar

How can I convert a datetime object to milliseconds since epoch (unix time) in Python?

>>> import datetime
>>> import time
>>> import calendar

>>> #your datetime object
>>> now =
>>> now
datetime.datetime(2013, 3, 19, 13, 0, 9, 351812)

>>> #use datetime module's timetuple method to get a `time.struct_time` object.[1]
>>> tt = datetime.datetime.timetuple(now)
>>> tt
time.struct_time(tm_year=2013, tm_mon=3, tm_mday=19, tm_hour=13, tm_min=0, tm_sec=9,     tm_wday=1, tm_yday=78, tm_isdst=-1)

>>> #If your datetime object is in utc you do this way. [2](see the first table on docs)
>>> sec_epoch_utc = calendar.timegm(tt) * 1000
>>> sec_epoch_utc

>>> #If your datetime object is in local timeformat you do this way
>>> sec_epoch_loc = time.mktime(tt) * 1000
>>> sec_epoch_loc



Add onClick event to document.createElement("th")

var newTH = document.createElement('th');
newTH.onclick = function() {
      //Your code here

How to set cellpadding and cellspacing in table with CSS?

The padding inside a table-divider (TD) is a padding property applied to the cell itself.


td, th {padding:0}

The spacing in-between the table-dividers is a space between cell borders of the TABLE. To make it effective, you have to specify if your table cells borders will 'collapse' or be 'separated'.


table, td, th {border-collapse:separate}
table {border-spacing:6px}

Try this : ( 27 100 results )

Search and replace a particular string in a file using Perl

A one liner:

perl -pi.back -e 's/<PREF>/ABCD/g;' inputfile

Is it possible to embed animated GIFs in PDFs?

Another possibility is LaTeX + animate package. You will need to provide the individual frames making the animation. The resulting pdf does NOT require any plugin, the animation is shown in Adobe reader

Add and remove a class on click using jQuery?

Try this in your Head section of the site:

$(function() {
    $('.menu_box_list li').click(function() {

How to include external Python code to use in other files?

You will need to import the other file as a module like this:

import Math

If you don't want to prefix your Calculate function with the module name then do this:

from Math import Calculate

If you want to import all members of a module then do this:

from Math import *

Edit: Here is a good chapter from Dive Into Python that goes a bit more in depth on this topic.

Using PUT method in HTML form

for people using laravel

<form method="post" ...>

MySQL vs MongoDB 1000 reads


speed comparison of MySQL & MongoDB in GOLANG1.6 & PHP5

system used for benchmark: DELL cpu i5 4th gen 1.70Ghz * 4 ram 4GB GPU ram 2GB

Speed comparison of RDBMS vs NoSQL for INSERT, SELECT, UPDATE, DELETE executing different number of rows 10,100,1000,10000,100000,1000000

Language used to execute is: PHP5 & Google fastest language GO 1.6

GOLANG with MySQL (engine = MyISAM)
num of rows             time taken
10                      1.195444ms
100                     6.075053ms
1000                    47.439699ms
10000                   483.999809ms
100000                  4.707089053s
1000000                 49.067407174s

num of rows             time taken
1000000                 872.709µs

num of rows             time taken
1000000                 20.717354746s

num of rows             time taken
1000000                 2.309209968s
100000                  257.411502ms
10000                   26.73954ms
1000                    3.483926ms
100                     915.17µs
10                      650.166µs

num of rows             time taken
1000000                 6.065949ms

GOLANG with MongoDB
num of rows             time taken
10                      2.067094ms
100                     8.841597ms
1000                    106.491732ms
10000                   998.225023ms
100000                  8.98172825s
1000000                 1m 29.63203158s

num of rows             time taken
1000000                 5.251337439s

        FIND & DISPLAY (with index declared)
num of rows             time taken
1000000                 21.540603252s

num of rows             time taken
1                       1.330954ms

PHP5 with MySQL (engine = MyISAM)
num of rows             time taken
 10                     0.0040680000000001s
 100                    0.011595s
 1000                   0.049718s
 10000                  0.457164s
 100000                 4s
 1000000                42s

num of rows             time taken
 1000000                <1s

            SELECT & DISPLAY
num of rows             time taken
  1000000               20s

PHP5 with MongoDB 
num of rows             time taken
10                      0.065744s
100                     0.190966s
1000                    0.2163s
10000                   1s
100000                  8s
1000000                 78s

num of rows             time taken
1000000                 <1s

            FIND & DISPLAY
num of rows             time taken
1000000                 7s

num of rows             time taken
1000000                 9s

How to get an IFrame to be responsive in iOS Safari?

I had an issue with width on the content pane creating a horizontal scroll bar for the iframe. It turned out that an image was holding the width wider than expected. I was able to solve it by setting the all of the images css max-width to a percent.

<meta name="viewport" content="width=device-width, initial-scale=1" />

img {
        max-width: 100%;

Mapping US zip code to time zone

In addition to Doug Kavendek answer. One could use the following approach to get closer to tz_database.

  1. Download [Free Zip Code Latitude and Longitude Database]
  2. Download [A shapefile of the TZ timezones of the world]
  3. Use any free library for shapefile querying (e.g. .NET Easy GIS .NET, LGPL).
    var shapeFile = new ShapeFile(shapeFilePath);
    var shapeIndex = shapeFile.GetShapeIndexContainingPoint(new PointD(long, lat), 0D);
    var attrValues = shapeFile.GetAttributeFieldValues(shapeIndex);
    var timeZoneId = attrValues[0];

P.S. Can't insert all the links :( So please use search.

jQuery val is undefined?

You should call the events after the document is ready, like this:

$(document).ready(function () {
  // Your code

This is because you are trying to manipulate elements before they are rendered by the browser.

So, in the case you posted it should look something like this

$(document).ready(function () {
  var editorTitle = $('#editorTitle').val();
  var editorText = $('#editorText').html();

Hope it helps.

Tips: always save your jQuery object in a variable for later use and only code that really need to run after the document have loaded should go inside the ready() function.

Detect & Record Audio in Python

You might want to look at csounds, also. It has several API's, including Python. It might be able to interact with an A-D interface and gather sound samples.

"CAUTION: provisional headers are shown" in Chrome debugger

I ran this issue when I tried to load main.js for require js for the second time after I made changes as a result from error . I just turned on in Developer Tools Settings "Disable Cache (When DevTools is Open)" . and that did the charm.

How to Create a script via batch file that will uninstall a program if it was installed on windows 7 64-bit or 32-bit

Assuming you're dealing with Windows 7 x64 and something that was previously installed with some sort of an installer, you can open regedit and search the keys under


(which references 32-bit programs) for part of the name of the program, or


(if it actually was a 64-bit program).

If you find something that matches your program in one of those, the contents of UninstallString in that key usually give you the exact command you are looking for (that you can run in a script).

If you don't find anything relevant in those registry locations, then it may have been "installed" by unzipping a file. Because you mentioned removing it by the Control Panel, I gather this likely isn't then case; if it's in the list of programs there, it should be in one of the registry keys I mentioned.

Then in a .bat script you can do

if exist "c:\program files\whatever\program.exe" (place UninstallString contents here)
if exist "c:\program files (x86)\whatever\program.exe" (place UninstallString contents here)

complex if statement in python

if x == 80 or x == 443 or 1024 <= x <= 65535

should definitely do

How to read input with multiple lines in Java

The easilest way is

import java.util.*;

public class Stdio4 {

public static void main(String[] args) {
    int a=0;
    int arr[] = new int[3];
    Scanner scan = new Scanner(;
    for(int i=0;i<3;i++)
         a = scan.nextInt();  //Takes input from separate lines

    for(int i=0;i<3;i++)
         System.out.println(arr[i]);   //outputs in separate lines also



Batch program to to check if process exists

Try this:

@echo off
set run=
tasklist /fi "imagename eq notepad.exe" | find ":" > nul
if errorlevel 1 set run=yes
if "%run%"=="yes" echo notepad is running
if "%run%"=="" echo notepad is not running

How do I read text from the clipboard?

The most upvoted answer above is weird in a way that it simply clears the Clipboard and then gets the content (which is then empty). One could clear the clipboard to be sure that some clipboard content type like "formated text" does not "cover" your plain text content you want to save in the clipboard.

The following piece of code replaces all newlines in the clipboard by spaces, then removes all double spaces and finally saves the content back to the clipboard:

import win32clipboard

c = win32clipboard.GetClipboardData()
c = c.replace('\n', ' ')
c = c.replace('\r', ' ')
while c.find('  ') != -1:
    c = c.replace('  ', ' ')

How do you run CMD.exe under the Local System Account?

if you can write a batch file that does not need to be interactive, try running that batch file as a service, to do what needs to be done.

Datagridview: How to set a cell in editing mode?

I know this is an old question, but none of the answers worked for me, because I wanted to reliably (always be able to) set the cell into edit mode when possibly executing other events like Toolbar Button clicks, menu selections, etc. that may affect the default focus after those events return. I ended up needing a timer and invoke. The following code is in a new component derived from DataGridView. This code allows me to simply make a call to myXDataGridView.CurrentRow_SelectCellFocus(myDataPropertyName); anytime I want to arbitrarily set a databound cell to edit mode (assuming the cell is Not in ReadOnly mode).

// If the DGV does not have Focus prior to a toolbar button Click, 
// then the toolbar button will have focus after its Click event handler returns.
// To reliably set focus to the DGV, we need to time it to happen After event handler procedure returns.

private string m_SelectCellFocus_DataPropertyName = "";
private System.Timers.Timer timer_CellFocus = null;

public void CurrentRow_SelectCellFocus(string sDataPropertyName)
  // This procedure is called by a Toolbar Button's Click Event to select and set focus to a Cell in the DGV's Current Row.
  m_SelectCellFocus_DataPropertyName = sDataPropertyName;
  timer_CellFocus = new System.Timers.Timer(10);
  timer_CellFocus.Elapsed += TimerElapsed_CurrentRowSelectCellFocus;

void TimerElapsed_CurrentRowSelectCellFocus(object sender, System.Timers.ElapsedEventArgs e)
  timer_CellFocus.Elapsed -= TimerElapsed_CurrentRowSelectCellFocus;
  // We have to Invoke the method to avoid raising a threading error

private void Select_Cell(string sDataPropertyName)
  /// When the Edit Mode is Enabled, set the initial cell to the Description
  foreach (DataGridViewCell dgvc in this.SelectedCells) 
    // Clear previously selected cells
    dgvc.Selected = false; 
  foreach (DataGridViewCell dgvc in this.CurrentRow.Cells)
    // Select the Cell by its DataPropertyName
    if (dgvc.OwningColumn.DataPropertyName == sDataPropertyName)
      this.CurrentCell = dgvc;
      dgvc.Selected = true;

Convert bytes to bits in python

Use ord when reading reading bytes:

byte_binary = bin(ord( # Add [2:] to remove the "0b" prefix


Using str.format():


Can I force a UITableView to hide the separator between empty cells?

I use the following:

UIView *view = [[UIView alloc] init];
myTableView.tableFooterView = view;
[view release];

Doing it in viewDidLoad. But you can set it anywhere.

Force div element to stay in same place, when page is scrolled

There is something wrong with your code.

position : absolute makes the element on top irrespective of other elements in the same page. But the position not relative to the scroll

This can be solved with position : fixed This property will make the element position fixed and still relative to the scroll.


You can check it out Here

git: fatal: I don't handle protocol '??http'

The solution is very simple:

1- Copy your git path. forexample :

2- Open notepad and Paste it. Then copy the path from notepad.

3- paste the path to command line

thats it.

Change image onmouseover

Here is an example:

HTML code:

<img id="myImg" src=""/>

JavaScript code:

$(document).ready(function() {
    $( "#myImg" ).mouseover(function(){
        $(this).attr("src", "");

    $( "#myImg" ).mouseout(function(){
        $(this).attr("src", "");

Edit: Sorry, your code was a bit strange. Now I understood what you were doing. ;) The hover method is better, of course.

How to make a new line or tab in <string> XML (eclipse/android)?

add this line at the top of string.xml

<?xml version="1.0" encoding="utf-8"?>

and use


from where you want to break your line.

ex. <string> Hello world. \n its awesome. <string>


Hello world.
its awesome.

What is the most efficient way to create HTML elements using jQuery?

I think you're using the best method, though you could optimize it to:


Using SSH keys inside docker container

In later versions of docker (17.05) you can use multi stage builds. Which is the safest option as the previous builds can only ever be used by the subsequent build and are then destroyed

See the answer to my stackoverflow question for more info

ReferenceError: describe is not defined NodeJs

You can also do like this:

  var mocha = require('mocha')
  var describe = mocha.describe
  var it =
  var assert = require('chai').assert

  describe('#indexOf()', function() {
    it('should return -1 when not present', function() {
      assert.equal([1,2,3].indexOf(4), -1)


Why is the use of alloca() not considered good practice?

One issue is that it isn't standard, although it's widely supported. Other things being equal, I'd always use a standard function rather than a common compiler extension.

How do I run Python code from Sublime Text 2?

seems the Ctrl+Break doesn't work on me, neither the Preference - User...

use keys, Alt ? t ? c

How to create multiple class objects with a loop in python?

Using a dictionary for unique names without a name list:

class MyClass:
    def __init__(self, name): = name

    def pretty_print_name(self):
    print("This object's name is {}.".format(

my_objects = {}
for i in range(1,11):
    name = 'obj_{}'.format(i)
    my_objects[name] = my_objects.get(name, MyClass(name = name))


"This object's name is obj_1."
"This object's name is obj_2."
"This object's name is obj_3."
"This object's name is obj_4."
"This object's name is obj_5."
"This object's name is obj_6."
"This object's name is obj_7."
"This object's name is obj_8."
"This object's name is obj_9."
"This object's name is obj_10."

Jquery: how to trigger click event on pressing enter key

Try This

<button class="click_on_enterkey" type="button" onclick="return false;">
  if(event.keyCode == 13){

How to handle change text of span

Span does not have 'change' event by default. But you can add this event manually.

Listen to the change event of span.

     //Do calculation and change value of other span2,span3 here
     $("#span2").text('calculated value');

And wherever you change the text in span1. Trigger the change event manually.


How to find a value in an excel column by vba code Cells.Find

Dim strFirstAddress As String
Dim searchlast As Range
Dim search As Range

Set search = ActiveSheet.Range("A1:A100")
Set searchlast = search.Cells(search.Cells.Count)

Set rngFindValue = ActiveSheet.Range("A1:A100").Find(Text, searchlast, xlValues)
If Not rngFindValue Is Nothing Then
  strFirstAddress = rngFindValue.Address
    Set rngFindValue = search.FindNext(rngFindValue)
  Loop Until rngFindValue.Address = strFirstAddress

Minimum Hardware requirements for Android development

Have a look at the android SDK system requirements Here

I'm guessing some extra RAM would help your developing experience...Also the emulator does take some time to start on even the speediest systems.

DropDownList's SelectedIndexChanged event not firing

Set DropDownList AutoPostBack property to true.


<asp:DropDownList ID="logList" runat="server" AutoPostBack="True" 

.gitignore file for java eclipse project

put .gitignore in your main catalog

git status (you will see which files you can commit)
git add -A
git commit -m "message"
git push

How to compare two columns in Excel and if match, then copy the cell next to it

It might be easier with vlookup. Try this:


The IFERROR() is for no matches, so that it throws "" in such cases.

VLOOKUP's first parameter is the value to 'look for' in the reference table, which is column G and H.

VLOOKUP will thus look for D2 in column G and return the value in the column index 2 (column G has column index 1, H will have column index 2), meaning that the value from column H will be returned.

The last parameter is 0 (or equivalently FALSE) to mean an exact match. That's what you need as opposed to approximate match.

jQuery AJAX Character Encoding

For my PHP application the solution was include utf8_decode function for each variable get in $_POST.


if( strtoupper($_SERVER['REQUEST_METHOD']) == "POST" ){
$variable = htmlentities($_POST['variable']); // wrong
$variable = htmlentities( utf8_decode($_POST['variable']) ); // right

Abraços!!! (Bye Bye!!!)

Response.Redirect to new window

<asp:Button ID="btnNewEntry" runat="Server" CssClass="button" Text="New Entry"

OnClick="btnNewEntry_Click" OnClientClick=" ='_blank';"/>

protected void btnNewEntry_Click(object sender, EventArgs e)


dynamically add and remove view to viewpager

I did a similar program. hope this would help you.In its first activity four grid data can be selected. On the next activity, there is a view pager which contains two mandatory pages.And 4 more pages will be there, which will be visible corresponding to the grid data selected.

Following is the mainactivty MainActivity

    package com.example.jeffy.viewpagerapp;
    import android.content.Context;
    import android.content.Intent;
    import android.content.SharedPreferences;
    import android.database.Cursor;
    import android.database.SQLException;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;
    import android.os.Bundle;
    import android.os.Parcel;
    import android.util.Log;
    import android.view.View;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.widget.AdapterView;
    import android.widget.Button;
    import android.widget.GridView;
    import java.lang.reflect.Array;
    import java.util.ArrayList;
    public class MainActivity extends AppCompatActivity {
    SharedPreferences pref;
    SharedPreferences.Editor editor;
    GridView gridView;
    Button button;
    private static final String DATABASE_NAME = "dbForTest.db";
    private static final int DATABASE_VERSION = 1;
    private static final String TABLE_NAME = "diary";
    private static final String TITLE = "id";
    private static final String BODY = "content";
    DBHelper  dbHelper = new DBHelper(this);
    ArrayList<String> frags = new ArrayList<String>();
    ArrayList<FragmentArray> fragmentArray = new ArrayList<FragmentArray>();
    String[] selectedData;
    Boolean port1=false,port2=false,port3=false,port4=false;
    int Iport1=1,Iport2=1,Iport3=1,Iport4=1,location;

    // This Data show in grid ( Used by adapter )
        CustomGridAdapter customGridAdapter = new           CustomGridAdapter(MainActivity.this,GRID_DATA);
    static final String[ ] GRID_DATA = new String[] {
            "1" ,
            "3" ,
    protected void onCreate(Bundle savedInstanceState) {
        Toolbar toolbar = (Toolbar) findViewById(;
        dbHelper = new DBHelper(this);
        final Bundle selected = new Bundle();
        button = (Button) findViewById(;
        pref = getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE);
        editor = pref.edit();
        gridView = (GridView) findViewById(;


        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                location = position + 1;
                if (position == 0) {
                    Iport1 = Iport1 % 2;
                    if (Iport1 % 2 == 1) {
                    } else {
                        dbHelper.updateContact(1, 0);
                if (position == 1) {
                    Iport1 = Iport1 % 2;
                    if (Iport2 % 2 == 1) {
                        dbHelper.updateContact(2, 1);
                    } else {
                if (position == 2) {
                    Iport3 = Iport3 % 2;
                    if (Iport3 % 2 == 1) {
                        dbHelper.updateContact(3, 1);
                    } else {
                        dbHelper.updateContact(3, 0);
                if (position == 3) {
                    Iport4 = Iport4 % 2;
                    if (Iport4 % 2 == 1) {
                        dbHelper.updateContact(4, 1);
                    } else {
        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                editor.putInt("port1", Iport1);
                editor.putInt("port2", Iport2);
                editor.putInt("port3", Iport3);
                editor.putInt("port4", Iport4);
                Intent i = new Intent(MainActivity.this,Main2Activity.class);
                    i.putExtra("3", "");
                    i.putExtra("5", "TabFragment5");
                    i.putExtra("6", "TabFragment6");
                dbHelper.updateContact(0, Iport1);
                dbHelper.updateContact(1, Iport2);
                dbHelper.updateContact(2, Iport3);
                dbHelper.updateContact(3, Iport4);

Here TabFragment1,TabFragment2 etc are fragment to be displayed on the viewpager.And I am not showing the layouts since they are out of scope of this project.

MainActivity will intent to Main2Activity Main2Activity

    package com.example.jeffy.viewpagerapp;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.FrameLayout;

import java.util.ArrayList;

public class Main2Activity extends AppCompatActivity {

    private ViewPager pager = null;
    private PagerAdapter pagerAdapter = null;
    DBHelper dbHelper;
    Cursor rs;
    int port1,port2,port3,port4;
    public void onCreate (Bundle savedInstanceState)
        Toolbar toolbar = (Toolbar) findViewById(;


        CollapsingToolbarLayout collapsingToolbar =
                (CollapsingToolbarLayout) findViewById(;

        NestedScrollView scrollView = (NestedScrollView) findViewById (;
        scrollView.setFillViewport (true);

        ArrayList<String > selectedPort = new ArrayList<String>();

        Intent intent = getIntent();
        String Tab3 = intent.getStringExtra("3");
        String Tab4 = intent.getStringExtra("4");
        String Tab5 = intent.getStringExtra("5");
        String Tab6 = intent.getStringExtra("6");

        TabLayout tabLayout = (TabLayout) findViewById(;

        if(Tab3!=null && !TextUtils.isEmpty(Tab3))
        if(Tab4!=null && !TextUtils.isEmpty(Tab4))
        if(Tab5!=null && !TextUtils.isEmpty(Tab5))
        if(Tab6!=null && !TextUtils.isEmpty(Tab6))

        dbHelper = new DBHelper(this);
//        rs=dbHelper.getData(1);
//        port1 = rs.getInt(rs.getColumnIndex("id"));
//        rs=dbHelper.getData(2);
//        port2 = rs.getInt(rs.getColumnIndex("id"));
//        rs=dbHelper.getData(3);
//        port3 = rs.getInt(rs.getColumnIndex("id"));
//        rs=dbHelper.getData(4);
//        port4 = rs.getInt(rs.getColumnIndex("id"));

        Log.i(">>>>>>>>>>>>>>", "port 1" + port1 + "port 2" + port2 + "port 3" + port3 + "port 4" + port4);

        if(Tab3!=null && !TextUtils.isEmpty(Tab3))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 0"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab4))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab5))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab6))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));

        final ViewPager viewPager = (ViewPager) findViewById(;
        final PagerAdapter adapter = new PagerAdapter
                (getSupportFragmentManager(), tabLayout.getTabCount(), selectedPort);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            public void onTabSelected(TabLayout.Tab tab) {

            public void onTabUnselected(TabLayout.Tab tab) {


            public void onTabReselected(TabLayout.Tab tab) {

//        setContentView(R.layout.activity_main2);
//        Toolbar toolbar = (Toolbar) findViewById(;
//        setSupportActionBar(toolbar);

//        TabLayout tabLayout = (TabLayout) findViewById(;
//        tabLayout.addTab(tabLayout.newTab().setText("View"));
//        tabLayout.addTab(tabLayout.newTab().setText("All"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 0"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
//        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);


ViewPagerAdapter Viewpageradapter.class

package com.example.jeffy.viewpagerapp;

import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

 * Created by Jeffy on 25-01-2016.
public class PagerAdapter extends FragmentStatePagerAdapter {
    int mNumOfTabs;

    List<String> values;

    public PagerAdapter(FragmentManager fm, int NumOfTabs, List<String> Port) {
        this.mNumOfTabs = NumOfTabs;
        this.values= Port;

    public Fragment getItem(int position) {

        String fragmentName = values.get(position);
        Class<?> clazz = null;
        Object fragment = null;
        try {
            clazz = Class.forName("com.example.jeffy.viewpagerapp."+fragmentName);
        } catch (ClassNotFoundException e) {
        try {
            fragment = clazz.newInstance();
        } catch (InstantiationException e) {
        } catch (IllegalAccessException e) {

        return (Fragment) fragment;

    public int getCount() {
        return values.size();

Layout for main2activity acticity_main2.xml

    < xmlns:android=""



                    app:layout_collapseMode="pin" />

                    app:layout_collapseMode="parallax" />





            android:layout_height="match_parent" >




Mainactivity layout

        <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android=""


    <GridView xmlns:android=""
        android:layout_height="fill_parent" >


        android:id="@+id/button" />



Hope this would help someone... Click up button please if this helped you

How to print table using Javascript?

One cheeky solution :

  function printDiv(divID) {
        //Get the HTML of div
        var divElements = document.getElementById(divID).innerHTML;
        //Get the HTML of whole page
        var oldPage = document.body.innerHTML;
        //Reset the page's HTML with div's HTML only
        document.body.innerHTML = 
          "<html><head><title></title></head><body>" + 
          divElements + "</body>";
        //Print Page
        //Restore orignal HTML
        document.body.innerHTML = oldPage;



<form id="form1" runat="server">
    <div id="printablediv" style="width: 100%; background-color: Blue; height: 200px">
        Print me I am in 1st Div
    <div id="donotprintdiv" style="width: 100%; background-color: Gray; height: 200px">
        I am not going to print
    <input type="button" value="Print 1st Div" onclick="javascript:printDiv('printablediv')" />

Load a HTML page within another HTML page

iframe is the tag which you can use for call other html pages into your web page

<iframe src="" name="targetframe" allowTransparency="true" scrolling="no" frameborder="0" >

What does ENABLE_BITCODE do in xcode 7?

Bitcode refers to to the type of code: "LLVM Bitcode" that is sent to iTunes Connect. This allows Apple to use certain calculations to re-optimize apps further (e.g: possibly downsize executable sizes). If Apple needs to alter your executable then they can do this without a new build being uploaded.

This differs from: Slicing which is the process of Apple optimizing your app for a user's device based on the device's resolution and architecture. Slicing does not require Bitcode. (Ex: only including @2x images on a 5s)

App Thinning is the combination of slicing, bitcode, and on-demand resources

Bitcode is an intermediate representation of a compiled program. Apps you upload to iTunes Connect that contain bitcode will be compiled and linked on the App Store. Including bitcode will allow Apple to re-optimize your app binary in the future without the need to submit a new version of your app to the store.

Apple Documentation on App Thinning

How can I find out the current route in Rails?

Based on @AmNaN suggestion (more details):

class ApplicationController < ActionController::Base

 def current_controller?(names)
  names.include?(params[:controller]) unless params[:controller].blank? || false

 helper_method :current_controller?


Now you can call it e.g. in a navigation layout for marking list items as active:

<ul class="nav nav-tabs">
  <li role="presentation" class="<%= current_controller?('items') ? 'active' : '' %>">
    <%= link_to user_items_path(current_user) do %>
      <i class="fa fa-cloud-upload"></i>
    <% end %>
  <li role="presentation" class="<%= current_controller?('users') ? 'active' : '' %>">
    <%= link_to users_path do %>
      <i class="fa fa-newspaper-o"></i>
    <% end %>
  <li role="presentation" class="<%= current_controller?('alerts') ? 'active' : '' %>">
    <%= link_to alerts_path do %>
      <i class="fa fa-bell-o"></i>
    <% end %>

For the users and alerts routes, current_page? would be enough:


But with nested routes and request for all actions of a controller (comparable with items), current_controller? was the better method for me:

 resources :users do 
  resources :items

The first menu entry is that way active for the following routes:

   /users/x/items        #index
   /users/x/items/x      #show
   /users/x/items/new    #new
   /users/x/items/x/edit #edit

Split string with delimiters in C

My code (tested):

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

int dtmsplit(char *str, const char *delim, char ***array, int *length ) {
  int i=0;
  char *token;
  char **res = (char **) malloc(0 * sizeof(char *));

  /* get the first token */
   token = strtok(str, delim);
   while( token != NULL ) 
        res = (char **) realloc(res, (i + 1) * sizeof(char *));
        res[i] = token;
      token = strtok(NULL, delim);
   *array = res;
   *length = i;
  return 1;

int main()
    int i;
    int c = 0;
    char **arr = NULL;

    int count =0;

    c = dtmsplit(str, ",", &arr, &count);
    printf("Found %d tokens.\n", count);

    for (i = 0; i < count; i++)
        printf("string #%d: %s\n", i, arr[i]);



Found 12 tokens.
string #0: JAN
string #1: FEB
string #2: MAR
string #3: APR
string #4: MAY
string #5: JUN
string #6: JUL
string #7: AUG
string #8: SEP
string #9: OCT
string #10: NOV
string #11: DEC

Pycharm does not show plot

I tried different solutions but what finally worked for me was You need to add this command after the myDataFrame.plot() command for this to take effect. If you have multiple plot just add the command at the end of your code. It will allow you to see every data you are plotting.

How to get the mouse position without events (without moving the mouse)?

You could try something similar to what Tim Down suggested - but instead of having elements for each pixel on the screen, create just 2-4 elements (boxes), and change their location, width, height dynamically to divide the yet possible locations on screen by 2-4 recursively, thus finding the mouse real location quickly.

For example - first elements take right and left half of screen, afterwards the upper and lower half. By now we already know in which quarter of screen the mouse is located, are able to repeat - discover which quarter of this space...

Replacing a character from a certain index

As strings are immutable in Python, just create a new string which includes the value at the desired index.

Assuming you have a string s, perhaps s = "mystring"

You can quickly (and obviously) replace a portion at a desired index by placing it between "slices" of the original.

s = s[:index] + newstring + s[index + 1:]

You can find the middle by dividing your string length by 2 len(s)/2

If you're getting mystery inputs, you should take care to handle indices outside the expected range

def replacer(s, newstring, index, nofail=False):
    # raise an error if index is outside of the string
    if not nofail and index not in range(len(s)):
        raise ValueError("index outside given string")

    # if not erroring, but the index is still not in the correct range..
    if index < 0:  # add it to the beginning
        return newstring + s
    if index > len(s):  # add it to the end
        return s + newstring

    # insert the new string between "slices" of the original
    return s[:index] + newstring + s[index + 1:]

This will work as

replacer("mystring", "12", 4)

TypeError: module.__init__() takes at most 2 arguments (3 given)

from Object import Object


From Class_Name import Class_name

If Object is a .py file.

Executing Javascript from Python

One more solution as PyV8 seems to be unmaintained and dependent on the old version of libv8.

PyMiniRacer It's a wrapper around the v8 engine and it works with the new version and is actively maintained.

pip install py-mini-racer

from py_mini_racer import py_mini_racer
ctx = py_mini_racer.MiniRacer()
function escramble_758(){
    var a,b,c
    a='+1 '
    return a+c+b;

And yes, you have to replace document.write with return as others suggested

How to adjust text font size to fit textview

In my case using app:autoSize was not solving all cases, for example it doesn't prevent word breaking

This is what I ended up using, it will resize down the text so that there are no word breaks on multiple lines

 * Resizes down the text size so that there are no word breaks
class AutoFitTextView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : AppCompatTextView(context, attrs, defStyleAttr) {

    private val paint = Paint()
    private val bounds = Rect()

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        var shouldResize = false
        paint.typeface = typeface
        var textSize = textSize
        paint.textSize = textSize
        val biggestWord: String = text.split(" ").maxByOrNull { it.count() } ?: return

        // Set bounds equal to the biggest word bounds
        paint.getTextBounds(biggestWord, 0, biggestWord.length, bounds)

        // Iterate to reduce the text size so that it makes the biggest word fit the line
        while ((bounds.width() + paddingStart + paddingEnd + paint.fontSpacing) > measuredWidth) {
            paint.textSize = textSize
            paint.getTextBounds(biggestWord, 0, biggestWord.length, bounds)
            shouldResize = true
        if (shouldResize) {
            setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize)

NSURLErrorDomain error codes description

The NSURLErrorDomain error codes are listed here

However, 400 is just the http status code ( being returned which means you've got something wrong with your request.

ERROR: Sonar server 'http://localhost:9000' can not be reached

Please check if postgres(or any other database service) is running properly.

How to convert JSON data into a Python object

dacite may also be a solution for you, it supports following features:

  • nested structures
  • (basic) types checking
  • optional fields (i.e. typing.Optional)
  • unions
  • forward references
  • collections
  • custom type hooks

from dataclasses import dataclass
from dacite import from_dict

class User:
    name: str
    age: int
    is_active: bool

data = {
    'name': 'John',
    'age': 30,
    'is_active': True,

user = from_dict(data_class=User, data=data)

assert user == User(name='John', age=30, is_active=True)

How to create friendly URL in php?

According to this article, you want a mod_rewrite (placed in an .htaccess file) rule that looks something like this:

RewriteEngine on
RewriteRule ^/news/([0-9]+)\.html /news.php?news_id=$1

And this maps requests from




Another possibility is doing it with forcetype, which forces anything down a particular path to use php to eval the content. So, in your .htaccess file, put the following:

<Files news>
    ForceType application/x-httpd-php

And then the index.php can take action based on the $_SERVER['PATH_INFO'] variable:

    echo $_SERVER['PATH_INFO'];
    // outputs '/63.html'

what does Error "Thread 1:EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)" mean?

Mine was about


was inside if closure in block. I just moved it out of closure.

Using GitLab token to clone without authentication

One possible way is using a deploy token ( After creating the token, use:

git clone https://<username>:<deploy_token> 

as mentioned in the link above.

Add border-bottom to table row <tr>


tr{border-top:thin solid}

Replace "thin solid" with CSS properties.

Importing a GitHub project into Eclipse

I think you need to create a branch before you can import into your local Eclipse, otherwise, there is an error leading to incapable of importing repository from Github or Bitbucket.

Is there a way to delete all the data from a topic or delete the topic before every run?

As I mentioned here Purge Kafka Queue:

Tested in Kafka 0.8.2, for the quick-start example: First, Add one line to file under config folder:


then, you can run this command:

bin/ --zookeeper localhost:2181 --delete --topic test

How to write :hover condition for a:before and a:after?

Write a:hover::before instead of a::before:hover: example.

How to get the selected index of a RadioGroup in Android

//use to get the id of selected item

int selectedID = myRadioGroup.getCheckedRadioButtonId();

//get the view of the selected item

View selectedView = (View)findViewById( selectedID);

How to define an empty object in PHP

As others have pointed out, you can use stdClass. However I think it is cleaner without the (), like so:

$obj = new stdClass;

However based on the question, it seems like what you really want is to be able to add properties to an object on the fly. You don't need to use stdClass for that, although you can. Really you can use any class. Just create an object instance of any class and start setting properties. I like to create my own class whose name is simply o with some basic extended functionality that I like to use in these cases and is nice for extending from other classes. Basically it is my own base object class. I also like to have a function simply named o(). Like so:

class o {
  // some custom shared magic, constructor, properties, or methods here

function o() {
  return new o;

If you don't like to have your own base object type, you can simply have o() return a new stdClass. One advantage is that o is easier to remember than stdClass and is shorter, regardless of if you use it as a class name, function name, or both. Even if you don't have any code inside your o class, it is still easier to memorize than the awkwardly capitalized and named stdClass (which may invoke the idea of a 'sexually transmitted disease class'). If you do customize the o class, you might find a use for the o() function instead of the constructor syntax. It is a normal function that returns a value, which is less limited than a constructor. For example, a function name can be passed as a string to a function that accepts a callable parameter. A function also supports chaining. So you can do something like: $result= o($internal_value)->some_operation_or_conversion_on_this_value();

This is a great start for a base "language" to build other language layers upon with the top layer being written in full internal DSLs. This is similar to the lisp style of development, and PHP supports it way better than most people realize. I realize this is a bit of a tangent for the question, but the question touches on what I think is the base for fully utilizing the power of PHP.

Windows: XAMPP vs WampServer vs EasyPHP vs alternative

I won't make such a big deal from this question.
It's not like choosing your new wife or car.
I'd never run any of these on a production server, so, to run just some quick tests any of them are equally good.

PHP __get and __set magic methods

Drop the public $bar; declaration and it should work as expected.

This API project is not authorized to use this API. Please ensure that this API is activated in the APIs Console

if faceing that error like geocoding access denied : so you can enable geocoding api service from getKey account.enter image description here

Find Java classes implementing an interface

Awhile ago, I put together a package for doing what you want, and more. (I needed it for a utility I was writing). It uses the ASM library. You can use reflection, but ASM turned out to perform better.

I put my package in an open source library I have on my web site. The library is here: You want to start with the with ClassFinder class.

The utility I wrote it for is an RSS reader that I still use every day, so the code does tend to get exercised. I use ClassFinder to support a plug-in API in the RSS reader; on startup, it looks in a couple directory trees for jars and class files containing classes that implement a certain interface. It's a lot faster than you might expect.

The library is BSD-licensed, so you can safely bundle it with your code. Source is available.

If that's useful to you, help yourself.

Update: If you're using Scala, you might find this library to be more Scala-friendly.

make div's height expand with its content

This problem arises when the Child elements of a Parent Div are floated. Here is the Latest Solution of the problem:

In your CSS file write the following class called .clearfix along with the pseudo selector :after

.clearfix:after {
    content: "";
    display: table;
    clear: both;

Then, in your HTML, add the .clearfix class to your parent Div. For example:

<div class="clearfix">

It should work always. You can call the class name as .group instead of .clearfix , as it will make the code more semantic. Note that, it is Not necessary to add the dot or even a space in the value of Content between the double quotation "". Also, overflow: auto; might solve the problem but it causes other problems like showing the scroll-bar and is not recommended.

Source: Blog of Lisa Catalano and Chris Coyier

Image Greyscale with CSS & re-color on mouse-over?

I use the following code on

Smooth transition from b/w to color with magnifying effect (scale)

    img.color_flip {
      filter: url(filters.svg#grayscale); /* Firefox 3.5+ */
      filter: gray; /* IE5+ */
      -webkit-filter: grayscale(1); /* Webkit Nightlies & Chrome Canary */
      -webkit-transition: all .5s ease-in-out;

    img.color_flip:hover {
      filter: none;
      -webkit-filter: grayscale(0);
      -webkit-transform: scale(1.1);

Animate a custom Dialog

I meet the same problem,but ,at last I solve the problem by followed way


Django return redirect() with parameters

Firstly, your URL definition does not accept any parameters at all. If you want parameters to be passed from the URL into the view, you need to define them in the urlconf.

Secondly, it's not at all clear what you are expecting to happen to the cleaned_data dictionary. Don't forget you can't redirect to a POST - this is a limitation of HTTP, not Django - so your cleaned_data either needs to be a URL parameter (horrible) or, slightly better, a series of GET parameters - so the URL would be in the form:


and so on. In this case, field1, field2 and field3 are not included in the URLconf definition - they are available in the view via request.GET.

So your urlconf would be:

url(r'^link/(?P<backend>\w+?)/$', my_function)

and the view would look like:

def my_function(request, backend):
   data = request.GET

and the reverse would be (after importing urllib):

return "%s?%s" % (redirect('my_function', args=(backend,)),

Edited after comment

The whole point of using redirect and reverse, as you have been doing, is that you go to the URL - it returns an Http code that causes the browser to redirect to the new URL, and call that.

If you simply want to call the view from within your code, just do it directly - no need to use reverse at all.

That said, if all you want to do is store the data, then just put it in the session:

request.session['temp_data'] = form.cleaned_data

MySQL Check if username and password matches in Database

//set vars
$user = $_POST['user'];
$pass = md5($_POST['pass']);

if ($user&&$pass) 
//connect to db
$connect = mysql_connect("$server","$username","$password") or die("not connecting");
mysql_select_db("users") or die("no db :'(");
$query = mysql_query("SELECT * FROM $tablename WHERE username='$user'");

$numrows = mysql_num_rows($query);

if ($numrows!=0)
//while loop
  while ($row = mysql_fetch_assoc($query))
    $dbusername = $row['username'];
    $dbpassword = $row['password'];
      die("incorrect username/password!");
  echo "user does not exist!";
    die("please enter a username and password!");

How do CORS and Access-Control-Allow-Headers work?

Yes, you need to have the header Access-Control-Allow-Origin: or Access-Control-Allow-Origin: * on both the OPTIONS response and the POST response. You should include the header Access-Control-Allow-Credentials: true on the POST response as well.

Your OPTIONS response should also include the header Access-Control-Allow-Headers: origin, content-type, accept to match the requested header.

Combine GET and POST request methods in Spring

@RequestMapping(value = "/testonly", method = { RequestMethod.GET, RequestMethod.POST })
public ModelAndView listBooksPOST(@ModelAttribute("booksFilter") BooksFilter filter,
        @RequestParam(required = false) String parameter1,
        @RequestParam(required = false) String parameter2, 
        BindingResult result, HttpServletRequest request) 
        throws ParseException {

    LONG CODE and SAME LONG CODE with a minor difference

if @RequestParam(required = true) then you must pass parameter1,parameter2

Use BindingResult and request them based on your conditions.

The Other way

@RequestMapping(value = "/books", method = RequestMethod.GET)
public ModelAndView listBooks(@ModelAttribute("booksFilter") BooksFilter filter,  
    two @RequestParam parameters, HttpServletRequest request) throws ParseException {



@RequestMapping(value = "/books", method = RequestMethod.POST)
public ModelAndView listBooksPOST(@ModelAttribute("booksFilter") BooksFilter filter, 
        BindingResult result) throws ParseException {


    do here your minor difference

private returntype myMethod(){

How to establish a connection pool in JDBC?

As answered by others, you will probably be happy with Apache Dbcp or c3p0. Both are popular, and work fine.

Regarding your doubt

Doesn't javax.sql or java.sql have pooled connection implementations? Why wouldn't it be best to use these?

They don't provide implementations, rather interfaces and some support classes, only revelant to the programmers that implement third party libraries (pools or drivers). Normally you don't even look at that. Your code should deal with the connections from your pool just as they were "plain" connections, in a transparent way.

How to concatenate two layers in keras?

Adding to the above-accepted answer so that it helps those who are using tensorflow 2.0

import tensorflow as tf

# some data
c1 = tf.constant([[1, 1, 1], [2, 2, 2]], dtype=tf.float32)
c2 = tf.constant([[2, 2, 2], [3, 3, 3]], dtype=tf.float32)
c3 = tf.constant([[3, 3, 3], [4, 4, 4]], dtype=tf.float32)

# bake layers x1, x2, x3
x1 = tf.keras.layers.Dense(10)(c1)
x2 = tf.keras.layers.Dense(10)(c2)
x3 = tf.keras.layers.Dense(10)(c3)

# merged layer y1
y1 = tf.keras.layers.Concatenate(axis=1)([x1, x2])

# merged layer y2
y2 = tf.keras.layers.Concatenate(axis=1)([y1, x3])

# print info
print("x1", x1.shape, "x2", x2.shape, "x3", x3.shape)
print("y1", y1.shape)
print("y2", y2.shape)


x1 (2, 10) x2 (2, 10) x3 (2, 10)
y1 (2, 20)
y2 (2, 30)

Jquery mouseenter() vs mouseover()

The mouseenter event differs from mouseover in the way it handles event bubbling. The mouseenter event, only triggers its handler when the mouse enters the element it is bound to, not a descendant. Refer:

The mouseleave event differs from mouseout in the way it handles event bubbling. The mouseleave event, only triggers its handler when the mouse leaves the element it is bound to, not a descendant. Refer:

List all sequences in a Postgres db 8.1 with SQL

Here is another one which has the schema name beside the sequence name

select nspname,relname from pg_class c join pg_namespace n on c.relnamespace=n.oid where relkind = 'S' order by nspname

Remove xticks in a matplotlib plot?

Alternatively, you can pass an empty tick position and label as

# for matplotlib.pyplot
# ---------------------
plt.xticks([], [])
# for axis object
# ---------------
# from Anakhand May 5 at 13:08
# for major ticks
# for minor ticks
ax.set_xticks([], minor=True)

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:


You can find more information about how to use Pyinstaller and customize the build process via the documentation.

You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

Error in : figure margins too large in R

enter image description here

Just zoom this area if you use RStudio.

How do I change the IntelliJ IDEA default JDK?

Download and unpack a JDK archive file (.tar.gz) and add it as a SDK in the 'Project Structure' dialog box ( Ctrl+Alt+Shift+S )

jdk 9 intellij click on the gif to enlarge

Make sure to set the 'Project language level' as well.

Understanding esModuleInterop in tsconfig file

Problem statement

Problem occurs when we want to import CommonJS module into ES6 module codebase.

Before these flags we had to import CommonJS modules with star (* as something) import:

// node_modules/moment/index.js
exports = moment
// index.ts file in our app
import * as moment from 'moment'
moment(); // not compliant with es6 module spec

// transpiled js (simplified):
const moment = require("moment");

We can see that * was somehow equivalent to exports variable. It worked fine, but it wasn't compliant with es6 modules spec. In spec, the namespace record in star import (moment in our case) can be only a plain object, not callable (moment() is not allowed).


With flag esModuleInterop we can import CommonJS modules in compliance with es6 modules spec. Now our import code looks like this:

// index.ts file in our app
import moment from 'moment'
moment(); // compliant with es6 module spec

// transpiled js with esModuleInterop (simplified):
const moment = __importDefault(require('moment'));

It works and it's perfectly valid with es6 modules spec, because moment is not namespace from star import, it's default import.

But how does it work? As you can see, because we did a default import, we called the default property on a moment object. But we didn't declare a default property on the exports object in the moment library. The key is the __importDefault function. It assigns module (exports) to the default property for CommonJS modules:

var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };

As you can see, we import es6 modules as they are, but CommonJS modules are wrapped into an object with the default key. This makes it possible to import defaults on CommonJS modules.

__importStar does the similar job - it returns untouched esModules, but translates CommonJS modules into modules with a default property:

// index.ts file in our app
import * as moment from 'moment'

// transpiled js with esModuleInterop (simplified):
const moment = __importStar(require("moment"));
// note that "moment" is now uncallable - ts will report error!
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (, k)) result[k] = mod[k];
    result["default"] = mod;
    return result;

Synthetic imports

And what about allowSyntheticDefaultImports - what is it for? Now the docs should be clear:

Allow default imports from modules with no default export. This does not affect code emit, just typechecking.

In moment typings we don't have specified default export, and we shouldn't have, because it's available only with flag esModuleInterop on. So allowSyntheticDefaultImports will not report an error if we want to import default from a third-party module which doesn't have a default export.

Exception : peer not authenticated

Expired certificate was the cause of our " peer not authenticated".

keytool -list -v -keystore filetruststore.ts

    Enter keystore password:
    Keystore type: JKS
    Keystore provider: SUN
    Your keystore contains 1 entry
    Alias name: somealias
    Creation date: Jul 26, 2012
    Entry type: PrivateKeyEntry
    Certificate chain length: 1
    Owner: CN=Unknown, OU=SomeOU, O="Some Company, Inc.", L=SomeCity, ST=GA, C=US
    Issuer: CN=Unknown, OU=SomeOU, O=Some Company, Inc.", L=SomeCity, ST=GA, C=US
    Serial number: 5011a47b
    Valid from: Thu Jul 26 16:11:39 EDT 2012 until: Wed Oct 24 16:11:39 EDT 2012

How to debug heap corruption errors?

If these errors occur randomly, there is high probability that you encountered data-races. Please, check: do you modify shared memory pointers from different threads? Intel Thread Checker may help to detect such issues in multithreaded program.

Text size and different android screen sizes

I know it's late but this might help someone...


        android:text="Your text goes here!"
        app:layout_constraintWidth_percent="0.50" />

Also, if you want to adjust the text size then try changing


That's all.

How to map with index in Ruby?

If you're using ruby 1.8.7 or 1.9, you can use the fact that iterator methods like each_with_index, when called without a block, return an Enumerator object, which you can call Enumerable methods like map on. So you can do: { |x,i| [x, i+2] }

In 1.8.6 you can do:

require 'enumerator'
arr.enum_for(:each_with_index).map { |x,i| [x, i+2] }

Installing PIL (Python Imaging Library) in Win7 64 bits, Python 2.6.4

I was having the same problem so I decided to download the source kit and install it according to how you posted above...

  1. Downloaded Source Kit
  2. Opened command prompt on that folder and typed python build
  3. Then I typed python install

It worked perfectly!

Now, some notes: when I typed python build, I saw that Microsoft Visual Studio v9.0 C compiler was being used to build everything.

So probably it's something with your compiler not correctly configured or something...

Anyways, that worked with me so thank you!

Creating a node class in Java

Welcome to Java! This Nodes are like a blocks, they must be assembled to do amazing things! In this particular case, your nodes can represent a list, a linked list, You can see an example here:

public class ItemLinkedList {
    private ItemInfoNode head;
    private ItemInfoNode tail;
    private int size = 0;

    public int getSize() {
        return size;

    public void addBack(ItemInfo info) {
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, null, tail);
            this.tail = node;

    public void addFront(ItemInfo info) {
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, head, null);
            this.head.prev = node;
            this.head = node;

    public ItemInfo removeBack() {
        ItemInfo result = null;
        if (head != null) {
            result =;
            if (tail.prev != null) {
       = null;
                tail = tail.prev;
            } else {
                head = null;
                tail = null;
        return result;

    public ItemInfo removeFront() {
        ItemInfo result = null;
        if (head != null) {
            result =;
            if ( != null) {
       = null;
                head =;
            } else {
                head = null;
                tail = null;
        return result;

    public class ItemInfoNode {

        private ItemInfoNode next;
        private ItemInfoNode prev;
        private ItemInfo info;

        public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev) {
   = info;
   = next;
            this.prev = prev;

        public void setInfo(ItemInfo info) {
   = info;

        public void setNext(ItemInfoNode node) {
            next = node;

        public void setPrev(ItemInfoNode node) {
            prev = node;

        public ItemInfo getInfo() {
            return info;

        public ItemInfoNode getNext() {
            return next;

        public ItemInfoNode getPrev() {
            return prev;


Declare ItemInfo as this:

public class ItemInfo {
    private String name;
    private String rfdNumber;
    private double price;
    private String originalPosition;

    public ItemInfo(){

    public ItemInfo(String name, String rfdNumber, double price, String originalPosition) { = name;
        this.rfdNumber = rfdNumber;
        this.price = price;
        this.originalPosition = originalPosition;

    public String getName() {
        return name;

    public void setName(String name) { = name;

    public String getRfdNumber() {
        return rfdNumber;

    public void setRfdNumber(String rfdNumber) {
        this.rfdNumber = rfdNumber;

    public double getPrice() {
        return price;

    public void setPrice(double price) {
        this.price = price;

    public String getOriginalPosition() {
        return originalPosition;

    public void setOriginalPosition(String originalPosition) {
        this.originalPosition = originalPosition;

Then, You can use your nodes inside the linked list like this:

public static void main(String[] args) {
    ItemLinkedList list = new ItemLinkedList();
    for (int i = 1; i <= 10; i++) {
        list.addBack(new ItemInfo("name-"+i, "rfd"+i, i, String.valueOf(i)));

    while (list.size() > 0){

What is the difference between attribute and property?

In Java (or other languages), using Property/Attribute depends on usage:

  • Property used when value doesn't change very often (usually used at startup or for environment variable)

  • Attributes is a value (object child) of an Element (object) which can change very often/all the time and be or not persistent