Programs & Examples On #Validate request

ValidateRequest="false" doesn't work in Asp.Net 4

This works without changing the validation mode.

You have to use a System.Web.Helpers.Validation.Unvalidated helper from System.Web.WebPages.dll. It is going to return a UnvalidatedRequestValues object which allows to access the form and QueryString without validation.

For example,

var queryValue = Server.UrlDecode(Request.Unvalidated("MyQueryKey"));

Works for me for MVC3 and .NET 4.

Allow User to input HTML in ASP.NET MVC - ValidateInput or AllowHtml

You Can Use [AllowHtml] To Your Project For Example

 public string Description { get; set; }

For Use This Code To Class Library You Instal This Package

Install-Package Microsoft.AspNet.Mvc

After Use This using

using System.Web.Mvc;

Installing PG gem on OS X - failure to build native extension

I believe the “correct” answer would be to first configure PATH correctly for by adding the following to ~/.profile (.zshrc or ~/.zprofile if using ZSH):

export PATH=$PATH:/Applications/

Then open a new tab or window in terminal and install the pg gem with:

ARCHFLAGS="-arch x86_64" gem install pg

Documented here:

File upload along with other object in Jersey restful web service

The request type is multipart/form-data and what you are sending is essentially form fields that go out as bytes with content boundaries separating different form fields.To send an object representation as form field (string), you can send a serialized form from the client that you can then deserialize on the server.

After all no programming environment object is actually ever traveling on the wire. The programming environment on both side are just doing automatic serialization and deserialization that you can also do. That is the cleanest and programming environment quirks free way to do it.

As an example, here is a javascript client posting to a Jersey example service,


    let data = new FormData();
    let account = {
        "name": "test account",
        "location": "Bangalore"

    data.append('file', this.file);
    data.append("accountKey", "44c85e59-afed-4fb2-884d-b3d85b051c44");
    data.append("device", "test001");
    data.append("account", JSON.stringify(account));
    let url = "http://localhost:9090/sensordb/test/file/multipart/upload";

    let config = {
        headers: {
            'Content-Type': 'multipart/form-data'
    }, data, config).then(function(data){

Here the client is sending a file, 2 form fields (strings) and an account object that has been stringified for transport. here is how the form fields look on the wire,

enter image description here

On the server, you can just deserialize the form fields the way you see fit. To finish this trivial example,

public Response uploadMultiPart(@Context ContainerRequestContext requestContext,
        @FormDataParam("file") InputStream fileInputStream,
        @FormDataParam("file") FormDataContentDisposition cdh,
        @FormDataParam("accountKey") String accountKey,
        @FormDataParam("account") String json)  {

    try {
        Account account = Account.deserialize(json);
    } catch (Exception e) {
    return Response.ok().build();

What's the best way to parse a JSON response from the requests library?

You can use json.loads:

import json
import requests

response = requests.get(...)
json_data = json.loads(response.text)

This converts a given string into a dictionary which allows you to access your JSON data easily within your code.

Or you can use @Martijn's helpful suggestion, and the higher voted answer, response.json().

How do I center text horizontally and vertically in a TextView?

Use android:gravity="center" to resolve your issue.

How to count the number of occurrences of a character in an Oracle varchar value?

REGEXP_COUNT should do the trick:

select REGEXP_COUNT('123-345-566', '-') from dual;

How do I work with dynamic multi-dimensional arrays in C?

// use new instead of malloc as using malloc leads to memory leaks `enter code here

    int **adj_list = new int*[rowsize];       
    for(int i = 0; i < rowsize; ++i)    

        adj_list[i] = new int[colsize];


How can I open a .db file generated by eclipse(android) form DDMS-->File explorer-->data--->data-->packagename-->database?

Depending on your platform you can use: sqlite3 file_name.db from the terminal. .tables will list the tables, .schema is full layout. SQLite commands like: select * from table_name; and such will print out the full contents. Type: ".exit" to exit. No need to download a GUI application.Use a semi-colon if you want it to execute a single command. Decent SQLite usage tutorial

Is there a 'foreach' function in Python 3?

This does the foreach in python 3

test = [0,1,2,3,4,5,6,7,8,"test"]

for fetch in test:

How to change Label Value using javascript

Based off your code, i created this Fiddle
You need to use

var cb = document.getElementsByName('field206451')[0];
var label = document.getElementsByName('label206451')[0];

if you want to use name attributes then you have to take the index since it is a list of items, not just a single one. Everything else worked good.

How to write asynchronous functions for Node.js

You seem to be confusing asynchronous IO with asynchronous functions. node.js uses asynchronous non-blocking IO because non blocking IO is better. The best way to understand it is to go watch some videos by ryan dahl.

How do I write asynchronous functions for Node?

Just write normal functions, the only difference is that they are not executed immediately but passed around as callbacks.

How should I implement error event handling correctly

Generally API's give you a callback with an err as the first argument. For example

database.query('something', function(err, result) {
  if (err) handle(err);

Is a common pattern.

Another common pattern is on('error'). For example

process.on('uncaughtException', function (err) {
  console.log('Caught exception: ' + err);


var async_function = function(val, callback){

The above function when called as

async_function(42, function(val) {

Will print 42 to the console asynchronously. In particular process.nextTick fires after the current eventloop callstack is empty. That call stack is empty after async_function and console.log(43) have run. So we print 43 followed by 42.

You should probably do some reading on the event loop.

How to write into a file in PHP?

$text = "Cats chase mice";
$filename = "somefile.txt";
$fh = fopen($filename, "a");
fwrite($fh, $text);

You use fwrite()

How to upload & Save Files with Desired name

This would work very well -- You can use HTML5 to allow only image files to be uploaded. This is the code for uploader.htm --

            function validateForm(){
                var image = document.getElementById("image").value;
                var name = document.getElementById("name").value;
                if (image =='')
                    return false;
                if(name =='')
                    return false;
                    return true;
                return false;

        <form method="post" action="upload.php" enctype="multipart/form-data">
            <input type="text" name="ext" size="30"/>
            <input type="text" name="name" id="name" size="30"/>
            <input type="file" accept="image/*" name="image" id="image" />
            <input type="submit" value='Save' onclick="return validateForm()"/>

Now the code for upload.php --

$name = $_POST['name'];
$ext = $_POST['ext'];
if (isset($_FILES['image']['name']))
    $saveto = "$name.$ext";
    move_uploaded_file($_FILES['image']['tmp_name'], $saveto);
    $typeok = TRUE;
        case "image/gif": $src = imagecreatefromgif($saveto); break;
        case "image/jpeg": // Both regular and progressive jpegs
        case "image/pjpeg": $src = imagecreatefromjpeg($saveto); break;
        case "image/png": $src = imagecreatefrompng($saveto); break;
        default: $typeok = FALSE; break;
    if ($typeok)
        list($w, $h) = getimagesize($saveto);
        $max = 100;
        $tw = $w;
        $th = $h;
        if ($w > $h && $max < $w)
            $th = $max / $w * $h;
            $tw = $max;
        elseif ($h > $w && $max < $h)
            $tw = $max / $h * $w;
            $th = $max;
        elseif ($max < $w)
            $tw = $th = $max;

        $tmp = imagecreatetruecolor($tw, $th);      
        imagecopyresampled($tmp, $src, 0, 0, 0, 0, $tw, $th, $w, $h);
        imageconvolution($tmp, array( // Sharpen image
            array(-1, -1, -1),
            array(-1, 16, -1),
            array(-1, -1, -1)      
        ), 8, 0);
        imagejpeg($tmp, $saveto);

Where is svn.exe in my machine?

First off, if subversion installed on your machine? if not look at what server your tortoisesvn is setup to connect to.

the default location when subversion is installed is c:\program files\subversion you can find svn.exe in c:\program files\subversion\bin where you can run your cmd line actions.

How to check if a specified key exists in a given S3 bucket using Java

In Amazon Java SDK 1.10+, you can use getStatusCode() to get the status code of the HTTP response, which will be 404 if the object does not exist.

import org.apache.http.HttpStatus;

try {
    AmazonS3 s3 = new AmazonS3Client();
    ObjectMetadata object = s3.getObjectMetadata("my-bucket", "my-client");
} catch (AmazonS3Exception e) {
    if (e.getStatusCode() == HttpStatus.SC_NOT_FOUND) {
        // bucket/key does not exist 
    } else {
        throw e;

getObjectMetadata() consumes fewer resources, and the response doesn't need to be closed like getObject().

In previous versions, you can use getErrorCode() and check for the appropriate string (depends on the version).

CSS3 :unchecked pseudo-class

I think you are trying to over complicate things. A simple solution is to just style your checkbox by default with the unchecked styles and then add the checked state styles.

input[type="checkbox"] {
  // Unchecked Styles
input[type="checkbox"]:checked {
  // Checked Styles

I apologize for bringing up an old thread but felt like it could have used a better answer.

EDIT (3/3/2016):

W3C Specs state that :not(:checked) as their example for selecting the unchecked state. However, this is explicitly the unchecked state and will only apply those styles to the unchecked state. This is useful for adding styling that is only needed on the unchecked state and would need removed from the checked state if used on the input[type="checkbox"] selector. See example below for clarification.

input[type="checkbox"] {
  /* Base Styles aka unchecked */
  font-weight: 300; // Will be overwritten by :checked
  font-size: 16px; // Base styling
input[type="checkbox"]:not(:checked) {
  /* Explicit Unchecked Styles */
  border: 1px solid #FF0000; // Only apply border to unchecked state
input[type="checkbox"]:checked {
  /* Checked Styles */
  font-weight: 900; // Use a bold font when checked

Without using :not(:checked) in the example above the :checked selector would have needed to use a border: none; to achieve the same affect.

Use the input[type="checkbox"] for base styling to reduce duplication.

Use the input[type="checkbox"]:not(:checked) for explicit unchecked styles that you do not want to apply to the checked state.

Read .mat files in Python

To read mat file to pandas dataFrame with mixed data types

mat=sio.loadmat('file.mat')# load mat-file
mdata = mat['myVar']  # variable in mat file 
ndata = {n: mdata[n][0,0] for n in mdata.dtype.names}
Columns = [n for n, v in ndata.items() if v.size == 1]
d=dict((c, ndata[c][0]) for c in Columns)

Override body style for content in an iframe

I have a blog and I had a lot of trouble finding out how to resize my embedded gist. Post manager only allows you to write text, place images and embed HTML code. Blog layout is responsive itself. It's built with Wix. However, embedded HTML is not. I read a lot about how it's impossible to resize components inside body of generated iFrames. So, here is my suggestion:

If you only have one component inside your iFrame, i.e. your gist, you can resize only the gist. Forget about the iFrame.

I had problems with viewport, specific layouts to different user agents and this is what solved my problem:

<script language="javascript" type="text/javascript" src=""></script>

<script language="javascript" type="text/javascript">

function windowSize() {
  let gist = document.querySelector('#gist92442763');

  let isMobile = {
    Android: function() {
        return /Android/i.test(navigator.userAgent)
    BlackBerry: function() {
        return /BlackBerry/i.test(navigator.userAgent)
    iOS: function() {
        return /iPhone|iPod/i.test(navigator.userAgent)
    Opera: function() {
        return /Opera Mini/i.test(navigator.userAgent)
    Windows: function() {
        return /IEMobile/i.test(navigator.userAgent) || /WPDesktop/i.test(navigator.userAgent)
    any: function() {
        return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows());

  if(isMobile.any()) { = "36%"; = "touch" = "absolute"
  } else { = "auto !important";


window.addEventListener('onresize', function() {


<style type="text/css">

.gist-data {
  max-height: 300px;

.gist-meta {
  display: none;


The logic is to set gist (or your component) css based on user agent. Make sure to identify your component first, before applying to query selector. Feel free to take a look how responsiveness is working.

How does Tomcat find the HOME PAGE of my Web App?

In any web application, there will be a web.xml in the WEB-INF/ folder.

If you dont have one in your web app, as it seems to be the case in your folder structure, the default Tomcat web.xml is under TOMCAT_HOME/conf/web.xml

Either way, the relevant lines of the web.xml are


so any file matching this pattern when found will be shown as the home page.

In Tomcat, a web.xml setting within your web app will override the default, if present.

Further Reading

How do I override the default home page loaded by Tomcat?

Differences between Octave and MATLAB?

Octave and matlab have many similarities. But Octave is a command line interface. You have to type each command in the command prompt, while matlab comes with best GUI. I recommend first you use matlab student version; after learning basic lessons use gnu octave permentaly. Now gnu octave comes with gui, but it is a development version now. There are some gui front end for gnu octave, like guioctave, xoctave(not free), DomainMath IDE,etc.

Eloquent - where not equal to

Or like this:

Code::whereNotIn('to_be_used_by_user_id', [2])->get();

How do you check current view controller class in Swift?

if let index = self.navigationController?.viewControllers.index(where: { $0 is MyViewController }) {
            let vc = self.navigationController?.viewControllers[vcIndex] as! MyViewController
            self.navigationController?.popToViewController(vc, animated: true)
        } else {
            self.navigationController?.popToRootViewController(animated: true)

Selecting multiple classes with jQuery

This should work:

$('.myClass, .myOtherClass').removeClass('theclass');

You must add the multiple selectors all in the first argument to $(), otherwise you are giving jQuery a context in which to search, which is not what you want.

It's the same as you would do in CSS.

How to convert a Django QuerySet to a list

Try this values_list('column_name', flat=True).

answers = Answer.objects.filter(id__in=[ for answer in answer_set.answers.all()]).values_list('column_name', flat=True)

It will return you a list with specified column values

How to plot a histogram using Matplotlib in Python with a list of data?

If you haven't installed matplotlib yet just try the command.

> pip install matplotlib

Library import

import matplotlib.pyplot as plot

The histogram data:

plot.hist(weightList,density=1, bins=20) 
plot.axis([50, 110, 0, 0.06]) 

Display histogram

And the output is like :

enter image description here

S3 Static Website Hosting Route All Paths to Index.html

If you landed here looking for solution that works with React Router and AWS Amplify Console - you already know that you can't use CloudFront redirection rules directly since Amplify Console does not expose CloudFront Distribution for the app.

Solution, however, is very simple - you just need to add a redirect/rewrite rule in Amplify Console like this:

Amplify Console Rewrite rule for React Router

See the following links for more info (and copy-friendly rule from the screenshot):

How to get response body using HttpURLConnection, when code other than 2xx is returned?

If the response code isn't 200 or 2xx, use getErrorStream() instead of getInputStream().

How to enable core dump in my Linux C++ program

You need to set ulimit -c. If you have 0 for this parameter a coredump file is not created. So do this: ulimit -c unlimited and check if everything is correct ulimit -a. The coredump file is created when an application has done for example something inappropriate. The name of the file on my system is core.<process-pid-here>.

'uint32_t' does not name a type

You need to include stdint.h

 #include <stdint.h>

How to get Node.JS Express to listen only on localhost?

Thanks for the info, think I see the problem. This is a bug in hive-go that only shows up when you add a host. The last lines of it are:

console.log("... port %d in %s mode", app.address().port, app.settings.env);

When you add the host on the first line, it is crashing when it calls app.address().port.

The problem is the potentially asynchronous nature of .listen(). Really it should be doing that console.log call inside a callback passed to listen. When you add the host, it tries to do a DNS lookup, which is async. So when that line tries to fetch the address, there isn't one yet because the DNS request is running, so it crashes.

Try this:

app.listen(3001, 'localhost', function() {
  console.log("... port %d in %s mode", app.address().port, app.settings.env);

jQuery slide left and show

You can add new function to your jQuery library by adding these line on your own script file and you can easily use fadeSlideRight() and fadeSlideLeft().

Note: you can change width of animation as you like instance of 750px.

$.fn.fadeSlideRight = function(speed,fn) {
    return $(this).animate({
        'opacity' : 1,
        'width' : '750px'
    },speed || 400, function() {
        $.isFunction(fn) &&;

$.fn.fadeSlideLeft = function(speed,fn) {
    return $(this).animate({
        'opacity' : 0,
        'width' : '0px'
    },speed || 400,function() {
        $.isFunction(fn) &&;

How to print float to n decimal places including trailing 0s?

I guess this is essentially putting it in a string, but this avoids the rounding error:

import decimal

def display(x):
    digits = 15
    temp = str(decimal.Decimal(str(x) + '0' * digits))
    return temp[:temp.find('.') + digits + 1]

Convert an image (selected by path) to base64 string

The following piece of code works for me:

string image_path="physical path of your image";
byte[] byes_array = System.IO.File.ReadAllBytes(Server.MapPath(image_path));
string base64String = Convert.ToBase64String(byes_array);

jQuery.css() - marginLeft vs. margin-left?

when is marginLeft being used:

    backgroundPosition:'10px -10px',
    minHeight: '40px'

As you can see, attributes that has a hyphen on it are converted to camelcased format. Using the margin-left from the previous code block above would make JavaScript bonkers because it will treat the hyphen as an operation for subtraction.

when is margin-left used:

$("div").css("margin-left","12px").css("background-position","10px -10px").css("min-height","40px");

Theoretically, both code blocks will do the same thing. We can allow hyphens on the second block because it is a string value while compared to the first block, it is somewhat an object.
Now that should make sense.

How to disable Home and other system buttons in Android?

Refreshing an old topic. I was able to achieve that my activity does not fold when the home button (physical or virtual) is pressed. Here is my code for activity onCreate() method:

        context = getApplicationContext();
        int windowType;
        if (Build.VERSION.SDK_INT>=26) windowType = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
        else windowType = WindowManager.LayoutParams.TYPE_TOAST;
        final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
                        | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
                        | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_FULLSCREEN,
        wm = (WindowManager) getApplicationContext()

        mTopView = (ViewGroup) getLayoutInflater().inflate(R.layout.activity_alarm_screen, null);
        //Set up your views here
        testView = mTopView.findViewById(;
        wm.addView(mTopView, params);

On API 26 and abovem you need to get screen overlay permission from the user. Tested on Android 7 and 8.

remove kernel on jupyter notebook

There two ways, what I found either go to the directory where kernels are residing and delete from there. Secondly, using this command below

List all kernels and grap the name of the kernel you want to remove

 jupyter kernelspec list 

to get the paths of all your kernels.

Then simply uninstall your unwanted-kernel

jupyter kernelspec remove kernel_name

Load More Posts Ajax Button in WordPress

If I'm not using any category then how can I use this code? Actually, I want to use this code for custom post type.

CSS force image resize and keep aspect ratio

Just add this to your css, It will automaticly shrink and expand with keeping the original ratio.

img {
    display: block;
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;

PHP mysql insert date format

First of all store $date=$_POST['your date field name'];

insert into **Your_Table Name** values('$date',**other fields**);

You must contain date in single cote (' ')

I hope it is helps.

What and When to use Tuple?

A tuple allows you to combine multiple values of possibly different types into a single object without having to create a custom class. This can be useful if you want to write a method that for example returns three related values but you don't want to create a new class.

Usually though you should create a class as this allows you to give useful names to each property. Code that extensively uses tuples will quickly become unreadable because the properties are called Item1, Item2, Item3, etc..

application/x-www-form-urlencoded or multipart/form-data?


I know this is 3 years too late, but Matt's (accepted) answer is incomplete and will eventually get you into trouble. The key here is that, if you choose to use multipart/form-data, the boundary must not appear in the file data that the server eventually receives.

This is not a problem for application/x-www-form-urlencoded, because there is no boundary. x-www-form-urlencoded can also always handle binary data, by the simple expedient of turning one arbitrary byte into three 7BIT bytes. Inefficient, but it works (and note that the comment about not being able to send filenames as well as binary data is incorrect; you just send it as another key/value pair).

The problem with multipart/form-data is that the boundary separator must not be present in the file data (see RFC 2388; section 5.2 also includes a rather lame excuse for not having a proper aggregate MIME type that avoids this problem).

So, at first sight, multipart/form-data is of no value whatsoever in any file upload, binary or otherwise. If you don't choose your boundary correctly, then you will eventually have a problem, whether you're sending plain text or raw binary - the server will find a boundary in the wrong place, and your file will be truncated, or the POST will fail.

The key is to choose an encoding and a boundary such that your selected boundary characters cannot appear in the encoded output. One simple solution is to use base64 (do not use raw binary). In base64 3 arbitrary bytes are encoded into four 7-bit characters, where the output character set is [A-Za-z0-9+/=] (i.e. alphanumerics, '+', '/' or '='). = is a special case, and may only appear at the end of the encoded output, as a single = or a double ==. Now, choose your boundary as a 7-bit ASCII string which cannot appear in base64 output. Many choices you see on the net fail this test - the MDN forms docs, for example, use "blob" as a boundary when sending binary data - not good. However, something like "!blob!" will never appear in base64 output.

Open the terminal in visual studio?

As tricky solution you can use Package Manager Console to execute cmd or PowerShell commends

Shortcut for Package Manager Console Alt T N O

Tested on Visual Studio 2017 Community Version

enter image description here

Also its available now as part of Visual Studio version 16.3 Preview 3

Shortcut Ctrl+` same as Visual Studio Code

Database Diagram Support Objects cannot be Installed ... no valid owner

EXEC dbo.sp_changedbowner @loginame = N'sa', @map = false

It works.

Missing MVC template in Visual Studio 2015

Just click on the "web" in left side-bar and select "ASP.NET Web Application", click "ok" and you will see next dialog:

Now, you can choose type of web application what you want.

What's the difference between "Layers" and "Tiers"?

  1. In plain english, the Tier refers to "each in a series of rows or levels of a structure placed one above the other" whereas the Layer refers to "a sheet, quantity, or thickness of material, typically one of several, covering a surface or body".

  2. Tier is a physical unit, where the code / process runs. E.g.: client, application server, database server;

    Layer is a logical unit, how to organize the code. E.g.: presentation (view), controller, models, repository, data access.

  3. Tiers represent the physical separation of the presentation, business, services, and data functionality of your design across separate computers and systems.

    Layers are the logical groupings of the software components that make up the application or service. They help to differentiate between the different kinds of tasks performed by the components, making it easier to create a design that supports reusability of components. Each logical layer contains a number of discrete component types grouped into sublayers, with each sublayer performing a specific type of task.

The two-tier pattern represents a client and a server.

In this scenario, the client and server may exist on the same machine, or may be located on two different machines. Figure below, illustrates a common Web application scenario where the client interacts with a Web server located in the client tier. This tier contains the presentation layer logic and any required business layer logic. The Web application communicates with a separate machine that hosts the database tier, which contains the data layer logic.

Layers vs Tiers

Advantages of Layers and Tiers:

  • Layering helps you to maximize maintainability of the code, optimize the way that the application works when deployed in different ways, and provide a clear delineation between locations where certain technology or design decisions must be made.

  • Placing your layers on separate physical tiers can help performance by distributing the load across multiple servers. It can also help with security by segregating more sensitive components and layers onto different networks or on the Internet versus an intranet.

A 1-Tier application could be a 3-Layer application.

Encrypt and decrypt a password in Java

EDIT : this answer is old. Usage of MD5 is now discouraged as it can easily be broken.

MD5 must be good enough for you I imagine? You can achieve it with MessageDigest.


There are also other algorithms listed here.

And here's an third party version of it, if you really want: Fast MD5

Items in JSON object are out of order using "json.dumps"?

As others have mentioned the underlying dict is unordered. However there are OrderedDict objects in python. ( They're built in in recent pythons, or you can use this: ).

I believe that newer pythons json implementations correctly handle the built in OrderedDicts, but I'm not sure (and I don't have easy access to test).

Old pythons simplejson implementations dont handle the OrderedDict objects nicely .. and convert them to regular dicts before outputting them.. but you can overcome this by doing the following:

class OrderedJsonEncoder( simplejson.JSONEncoder ):
   def encode(self,o):
      if isinstance(o,OrderedDict.OrderedDict):
         return "{" + ",".join( [ self.encode(k)+":"+self.encode(v) for (k,v) in o.iteritems() ] ) + "}"
         return simplejson.JSONEncoder.encode(self, o)

now using this we get:

>>> import OrderedDict
>>> unordered={"id":123,"name":"a_name","timezone":"tz"}
>>> ordered = OrderedDict.OrderedDict( [("id",123), ("name","a_name"), ("timezone","tz")] )
>>> e = OrderedJsonEncoder()
>>> print e.encode( unordered )
{"timezone": "tz", "id": 123, "name": "a_name"}
>>> print e.encode( ordered )

Which is pretty much as desired.

Another alternative would be to specialise the encoder to directly use your row class, and then you'd not need any intermediate dict or UnorderedDict.

Message "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout"

// In jest.setup.js

If on Jest <= 23:

// In jest.config.js
module.exports = {
  setupTestFrameworkScriptFile: './jest.setup.js'

If on Jest > 23:

// In jest.config.js
module.exports = {
  setupFilesAfterEnv: ['./jest.setup.js']

Is there a default password to connect to vagrant when using `homestead ssh` for the first time?

I've a same problem. After move machine from restore of Time Machine, on another host. There problem it's that ssh key for vagrant it's not your key, it's a key on Homestead directory.

Solution for me:

  • Use vagrant / vagrant for access ti VM of Homestead
  • vagrant ssh-config for see config of ssh

run on terminal

vagrant ssh-config
Host default
User vagrant
Port 2222
UserKnownHostsFile /dev/null
StrictHostKeyChecking no
PasswordAuthentication no
IdentityFile "/Users/MYUSER/.vagrant.d/insecure_private_key"
IdentitiesOnly yes
LogLevel FATAL
ForwardAgent yes

Create a new pair of SSH keys

ssh-keygen -f /Users/MYUSER/.vagrant.d/insecure_private_key

Copy content of public key

cat /Users/MYUSER/.vagrant.d/

On other shell in Homestead VM Machine copy into authorized_keys

vagrant@homestad:~$ echo 'CONTENT_PASTE_OF_PRIVATE_KEY' >> ~/.ssh/authorized_keys

Now can access with vagrant ssh

Django optional url parameters

You can use nested routes

Django <1.8

urlpatterns = patterns(''
    url(r'^project_config/', include(patterns('',
        url(r'^$', ProjectConfigView.as_view(), name="project_config")
        url(r'^(?P<product>\w+)$', include(patterns('',
            url(r'^$', ProductView.as_view(), name="product"),
            url(r'^(?P<project_id>\w+)$', ProjectDetailView.as_view(), name="project_detail")

Django >=1.8

urlpatterns = [
    url(r'^project_config/', include([
        url(r'^$', ProjectConfigView.as_view(), name="project_config")
        url(r'^(?P<product>\w+)$', include([
            url(r'^$', ProductView.as_view(), name="product"),
            url(r'^(?P<project_id>\w+)$', ProjectDetailView.as_view(), name="project_detail")

This is a lot more DRY (Say you wanted to rename the product kwarg to product_id, you only have to change line 4, and it will affect the below URLs.

Edited for Django 1.8 and above

Display image as grayscale using matplotlib

I would use the get_cmap method. Ex.:

import matplotlib.pyplot as plt

plt.imshow(matrix, cmap=plt.get_cmap('gray'))

How can I get city name from a latitude and longitude point?

Here is the latest sample of Google's geocode Web Service,-73.961452&key=YOUR_API_KEY

Simply change the YOUR_API_KEY to the API key you get from Google Geocoding API

P/S: Geocoding API is under Places NOT Maps ;)

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

To create a model that references another, use the Ruby on Rails model generator:

$ rails g model wheel car:references

That produces app/models/wheel.rb:

class Wheel < ActiveRecord::Base
  belongs_to :car

And adds the following migration:

class CreateWheels < ActiveRecord::Migration
  def self.up
    create_table :wheels do |t|
      t.references :car


  def self.down
    drop_table :wheels

When you run the migration, the following will end up in your db/schema.rb:

$ rake db:migrate

create_table "wheels", :force => true do |t|
  t.integer  "car_id"
  t.datetime "created_at"
  t.datetime "updated_at"

As for documentation, a starting point for rails generators is Ruby on Rails: A Guide to The Rails Command Line which points you to API Documentation for more about available field types.

How to display a list using ViewBag

     //controller  You can use this way

    public ActionResult Index()
      List<Fund> fundList = db.Funds.ToList();
     ViewBag.Funds = fundList;
        return View();

<--View ; You can use this way html-->

@foreach (var item in (List<Fund>)ViewBag.Funds)

Python: Converting string into decimal number

use the built in float() function in a list comprehension.

A2 = [float(v.replace('"','').strip()) for v in A1]

How to show text in combobox when no item selected?

Credit must be given to IronRazerz in a response to TextBox watermark (CueBanner) which goes away when user types in single line TextBox (not for RichTextBox).

You will need to declare the following in your class:

private const int CB_SETCUEBANNER = 0x1703;

[System.Runtime.InteropServices.DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
private static extern int SendMessage(IntPtr hWnd, int msg, int wParam, [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.LPWStr)]string lParam);

Then you can use it with something like:

SendMessage(this.comboBox1.Handle, CB_SETCUEBANNER, 0, "Please select an item...");

This is assuming the Combo Box's DropDownStyle is set to DropDownList, as is the original poster's question.

This should result in something like the following:

Placeholder text for combo box drop down list

Is it possible to use Visual Studio on macOS?

While Parallels is technically a VM it is capable of running games in high resolution at a high frame rate. If you run Parallels in Coherence mode it completely integrates Windows 7 into OS X and .Net framework is fully supported. So yes you can install Visual Studio on your Mac however the Apps you created would only run of windows computers unless they were web based.

WP -- Get posts by category?

Create a taxonomy field category (field name = post_category) and import it in your template as shown below:

          $categ = get_field('post_category');  
          $args = array( 'posts_per_page' => 6,
         'category_name' => $categ->slug );
          $myposts = get_posts( $args );
          foreach ( $myposts as $post ) : setup_postdata( $post ); ?>
            //your code here
          <?php endforeach; 

How to use table variable in a dynamic sql statement?

Using Temp table solves the problem but I ran into issues using Exec so I went with the following solution of using sp_executesql:

Create TABLE #tempJoin ( Old_ID int, New_ID int);

declare @table_name varchar(128);

declare @strSQL nvarchar(3072);

set @table_name = 'Object';

--build sql sting to execute
set @strSQL='INSERT INTO '+@table_name+' SELECT '+@columns+' FROM #tempJoin CJ
                        Inner Join '+@table_name+' sourceTbl On CJ.Old_ID = sourceTbl.Object_ID'

**exec sp_executesql @strSQL;**

jQuery UI Slider (setting programmatically)

Mal's answer was the only one that worked for me (maybe jqueryUI has changed), here is a variant for dealing with a range:

$( "#slider-range" ).slider('values',0,lowerValue);
$( "#slider-range" ).slider('values',1,upperValue);
$( "#slider-range" ).slider("refresh");

Google Text-To-Speech API

An additional alternative is: a simple example JsFiddle is Here


<div id="container">
<input type="text" name="text">
<button id="gspeech" class="say">Say It</button>
<audio id="player1" src="" class="speech" hidden></audio>



 $('#gspeech').on('click', function(){
        var text = $('input[name="text"]').val();
        responsiveVoice.speak("" + text +"");
        <!-- -->


External Resource:

php resize image on upload

You can use Imagine library also. It uses GD and Imagick.

C function that counts lines in file

You have a ; at the end of the if. Change:

  if (fp == NULL);
  return 0;


  if (fp == NULL) 
    return 0;

perform an action on checkbox checked or unchecked event on html form

Given you use JQuery, you can do something like below :


<form id="myform">
    syn<input type="checkbox" name="checkfield" id="g01-01"  onclick="doalert()"/>


function doalert() {
  if ($("#g01-01").is(":checked")) {
    alert ("hi");
  } else {
    alert ("bye");

Cannot redeclare function php

You (or Joomla) is likely including this file multiple times. Enclose your function in a conditional block:

if (!function_exists('parseDate')) {
    // ... proceed to declare your function

Generate 'n' unique random numbers within a range

You could add to a set until you reach n:

setOfNumbers = set()
while len(setOfNumbers) < n:
    setOfNumbers.add(random.randint(numLow, numHigh))

Be careful of having a smaller range than will fit in n. It will loop forever, unable to find new numbers to insert up to n

How to open a web server port on EC2 instance

Follow the steps that are described on this answer just instead of using the drop down, type the port (8787) in "port range" an then "Add rule".

Go to the "Network & Security" -> Security Group settings in the left hand navigation

enter image description here Find the Security Group that your instance is apart of Click on Inbound Rules enter image description here Use the drop down and add HTTP (port 80) enter image description here Click Apply and enjoy

"RuntimeError: Make sure the Graphviz executables are on your system's path" after installing Graphviz 2.38

1.install windows package from: and download msi file

Add in Environmental variables 2. Add C:\Program Files (x86)\Graphviz2.38\bin to User path

  1. Add C:\Program Files (x86)\Graphviz2.38\bin\dot.exe to System Path

  2. Restart your python notebook.

It will work.

How to add a second css class with a conditional value in razor MVC 4

I believe that there can still be and valid logic on views. But for this kind of things I agree with @BigMike, it is better placed on the model. Having said that the problem can be solved in three ways:

Your answer (assuming this works, I haven't tried this):

<div class="details @(@Model.Details.Count > 0 ? "show" : "hide")">

Second option:

@if (Model.Details.Count > 0) {
    <div class="details show">
else {
    <div class="details hide">

Third option:

<div class="@("details " + (Model.Details.Count>0 ? "show" : "hide"))">

Has anyone ever got a remote JMX JConsole to work?

I'm using boot2docker to run docker containers with Tomcat inside and I've got the same problem, the solution was to:

  • Add -Djava.rmi.server.hostname=
  • Use the same JMX port in host and docker container, for instance: docker run ... -p 9999:9999 .... Using different ports does not work.

Removing header column from pandas dataframe

How to get rid of a header(first row) and an index(first column).

To write to CSV file:

df = pandas.DataFrame(your_array)
df.to_csv('your_array.csv', header=False, index=False)

To read from CSV file:

df = pandas.read_csv('your_array.csv')
a = df.values

If you want to read a CSV file that doesn't contain a header, pass additional parameter header:

df = pandas.read_csv('your_array.csv', header=None)

How to test that a registered variable is not empty?

- name: set pkg copy dir name
    PKG_DIR: >-
      {% if ansible_os_family == "RedHat" %}centos/*.rpm
      {%- elif ansible_distribution == "Ubuntu" %}ubuntu/*.deb
      {%- elif ansible_distribution == "Kylin Linux Advanced Server" %}kylin/*.deb
      {%- else %}{%- endif %}

Effective method to hide email from spam bots

There are probably bots that recognize the [at] and other disguises as @ symbol. So this is not a really effective method.

Sure you could use some encodings like URL encode or HTML character references (or both):

// PHP example
// encodes every character using URL encoding (%hh)
function foo($str) {
    $retVal = '';
    $length = strlen($str);
    for ($i=0; $i<$length; $i++) $retVal.=sprintf('%%%X', ord($str[$i]));
    return $retVal;
// encodes every character into HTML character references (&#xhh;)
function bar($str) {
    $retVal = '';
    $length = strlen($str);
    for ($i=0; $i<$length; $i++) $retVal.=sprintf('&#x%X;', ord($str[$i]));
    return $retVal;

$email = '[email protected]';
echo '<a href="'.bar('mailto:?to=' . foo(','.$email.'')).'">mail me</a>';

// output
// <a href="&#x6D;&#x61;&#x69;&#x6C;&#x74;&#x6F;&#x3A;&#x3F;&#x74;&#x6F;&#x3D;&#x25;&#x32;&#x43;&#x25;&#x37;&#x35;&#x25;&#x37;&#x33;&#x25;&#x36;&#x35;&#x25;&#x37;&#x32;&#x25;&#x34;&#x30;&#x25;&#x36;&#x35;&#x25;&#x37;&#x38;&#x25;&#x36;&#x31;&#x25;&#x36;&#x44;&#x25;&#x37;&#x30;&#x25;&#x36;&#x43;&#x25;&#x36;&#x35;&#x25;&#x32;&#x45;&#x25;&#x36;&#x33;&#x25;&#x36;&#x46;&#x25;&#x36;&#x44;">mail me</a>

But as it is legal to use them, every browser/e-mail client should handle these encodings too.

How to set background color of an Activity to white programmatically?

The best method right now is of course

getWindow().getDecorView().setBackgroundColor(ContextCompat.getColor(MainActivity.this, R.color.main_activity_background_color));

Please be aware though, if you have anything set as the background color in Designer, it will overwrite anything you try to set in your code.

Calling JMX MBean method from a shell script

I'm not sure about bash-like environment. You might try some simple wrapper programs in Java (with program arguments) that invoke your MBeans on the remote server. You can then call these wrappers from the shell script

If you can use something like Python or Perl, you might be interested in JSR-262 which allows you to expose JMX operations over web services. This is scheduled to be included in Java 7 but you might be able to use a release candidate of the reference implementation

.NET / C# - Convert char[] to string

Use the string constructor which accepts chararray as argument, start position and length of array. Syntax is given below:

string charToString = new string(CharArray, 0, CharArray.Count());

MATLAB - multiple return values from a function?

Matlab allows you to return multiple values as well as receive them inline.

When you call it, receive individual variables inline:

[array, listp, freep] = initialize(size)

'cout' was not declared in this scope

Use std::cout, since cout is defined within the std namespace. Alternatively, add a using std::cout; directive.

Python error message io.UnsupportedOperation: not readable

Use a+ to open a file for reading, writing as well as create it if it doesn't exist.

a+ Opens a file for both appending and reading. The file pointer is at the end of the file if the file exists. The file opens in the append mode. If the file does not exist, it creates a new file for reading and writing. -Python file modes

with open('"File.txt', 'a+') as file:

Note: opening file in a with block makes sure that the file is properly closed at the block's end, even if an exception is raised on the way. It's equivalent to try-finally, but much shorter.

Combining CSS Pseudo-elements, ":after" the ":last-child"

I am using the same technique in a media query which effectively turns a bullet list into an inline list on smaller devices as they save space.

So the change from:

  • List item 1
  • List item 2
  • List item 3


List Item 1; List Item 2; List Item 3.

git undo all uncommitted or unsaved changes

Another option to undo changes that weren't staged for commit is to run:

git restore <file>

To discard changes in the working directory.

What is the difference between "is None" and "== None"

It depends on what you are comparing to None. Some classes have custom comparison methods that treat == None differently from is None.

In particular the output of a == None does not even have to be boolean !! - a frequent cause of bugs.

For a specific example take a numpy array where the == comparison is implemented elementwise:

import numpy as np
a = np.zeros(3) # now a is array([0., 0., 0.])
a == None #compares elementwise, outputs array([False, False, False]), i.e. not boolean!!!
a is None #compares object to object, outputs False

Java JTable getting the data of the selected row

You can use the following code to get the value of the first column of the selected row of your table.

int column = 0;
int row = table.getSelectedRow();
String value = table.getModel().getValueAt(row, column).toString();

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

Look at the Inner Exception and find out what object might have caused the problem, you might have changed its name.

JavaScript DOM remove element

removeChild should be invoked on the parent, i.e.:


In your example, you should be doing something like:

if (frameid) {

UnicodeDecodeError: 'charmap' codec can't decode byte X in position Y: character maps to <undefined>

The file in question is not using the CP1252 encoding. It's using another encoding. Which one you have to figure out yourself. Common ones are Latin-1 and UTF-8. Since 0x90 doesn't actually mean anything in Latin-1, UTF-8 (where 0x90 is a continuation byte) is more likely.

You specify the encoding when you open the file:

file = open(filename, encoding="utf8")

How can I split and parse a string in Python?

"2.7.0_bf4fda703454".split("_") gives a list of strings:

In [1]: "2.7.0_bf4fda703454".split("_")
Out[1]: ['2.7.0', 'bf4fda703454']

This splits the string at every underscore. If you want it to stop after the first split, use "2.7.0_bf4fda703454".split("_", 1).

If you know for a fact that the string contains an underscore, you can even unpack the LHS and RHS into separate variables:

In [8]: lhs, rhs = "2.7.0_bf4fda703454".split("_", 1)

In [9]: lhs
Out[9]: '2.7.0'

In [10]: rhs
Out[10]: 'bf4fda703454'

An alternative is to use partition(). The usage is similar to the last example, except that it returns three components instead of two. The principal advantage is that this method doesn't fail if the string doesn't contain the separator.

How can I force users to access my page over HTTPS instead of HTTP?

You shouldn't for security reasons. Especially if cookies are in play here. It leaves you wide open to cookie-based replay attacks.

Either way, you should use Apache control rules to tune it.

Then you can test for HTTPS being enabled and redirect as-needed where needed.

You should redirect to the pay page only using a FORM POST (no get), and accesses to the page without a POST should be directed back to the other pages. (This will catch the people just hot-jumping.)

Is a good place to start, apologies for not providing more. But you really should shove everything through SSL.

It's over-protective, but at least you have less worries.

how to check confirm password field in form without reloading page

Solution Using jQuery

 <script src=""></script>

    #form label{float:left; width:140px;}
    #error_msg{color:red; font-weight:bold;}

        var $submitBtn = $("#form input[type='submit']");
        var $passwordBox = $("#password");
        var $confirmBox = $("#confirm_password");
        var $errorMsg =  $('<span id="error_msg">Passwords do not match.</span>');

        // This is incase the user hits refresh - some browsers will maintain the disabled state of the button.

        function checkMatchingPasswords(){
            if($confirmBox.val() != "" && $passwordBox.val != ""){
                if( $confirmBox.val() != $passwordBox.val() ){
                    $submitBtn.attr("disabled", "disabled");

        function resetPasswordError(){
            var $errorCont = $("#error_msg");
            if($errorCont.length > 0){

        $("#confirm_password, #password")
             .on("keydown", function(e){
                /* only check when the tab or enter keys are pressed
                 * to prevent the method from being called needlessly  */
                if(e.keyCode == 13 || e.keyCode == 9) {
             .on("blur", function(){                    
                // also check when the element looses focus (clicks somewhere else)
            .on("focus", function(){
                // reset the error message when they go to make a change


And update your form accordingly:

<form id="form" name="form" method="post" action="registration.php"> 
    <label for="username">Username : </label>
    <input name="username" id="username" type="text" /></label><br/>

    <label for="password">Password :</label> 
    <input name="password" id="password" type="password" /><br/>

    <label for="confirm_password">Confirm Password:</label>
    <input type="password" name="confirm_password" id="confirm_password" /><br/>

    <input type="submit" name="submit"  value="registration"  />

This will do precisely what you asked for:

  • validate that the password and confirm fields are equal without clicking the register button
  • If password and confirm password field will not match it will place an error message at the side of confirm password field and disable registration button

It is advisable not to use a keyup event listener for every keypress because really you only need to evaluate it when the user is done entering information. If someone types quickly on a slow machine, they may perceive lag as each keystroke will kick off the function.

Also, in your form you are using labels wrong. The label element has a "for" attribute which should correspond with the id of the form element. This is so that when visually impaired people use a screen reader to call out the form field, it will know text belongs to which field.

How to convert .pfx file to keystore with private key?

If you work with JDK 1.5 or below the keytool utility will not have the -importkeystore option (see JDK 1.5 keytool documentation) and the solution by MikeD will be available only by transferring the .pfx on a machine with a newer JDK (1.6 or above).

Another option in JDK 1.5 or below (if you have Oracle WebLogic product), is to follow the instructions from this Oracle document: Using PFX and PEM Certificate Formats with Keystores. It describes the conversion into .pem format, how to extract certificates information from this textual format, and import it into .jks format with java utils.ImportPrivateKey utility (this is an utility included with WebLogic product).

Delete specific line from a text file?

One way to do it if the file is not very big is to load all the lines into an array:

string[] lines = File.ReadAllLines("filename.txt");
string[] newLines = RemoveUnnecessaryLine(lines);
File.WriteAllLines("filename.txt", newLines);

Is there a way to suppress JSHint warning for one given line?

As you can see in the documentation of JSHint you can change options per function or per file. In your case just place a comment in your file or even more local just in the function that uses eval:

/*jshint evil:true */

function helloEval(str) {
    /*jshint evil:true */

How to import a SQL Server .bak file into MySQL?

I highly doubt it. You might want to use DTS/SSIS to do this as Levi says. One think that you might want to do is start the process without actually importing the data. Just do enough to get the basic table structures together. Then you are going to want to change around the resulting table structure, because whatever structure tat will likely be created will be shaky at best.

You might also have to take this a step further and create a staging area that takes in all the data first n a string (varchar) form. Then you can create a script that does validation and conversion to get it into the "real" database, because the two databases don't always work well together, especially when dealing with dates.

Oracle (ORA-02270) : no matching unique or primary key for this column-list error

Most Probably when you have a missing Primary key is not defined from parent table. then It occurs.

Like Add the primary key define in parent as below:


Hope this will work.

Android Webview gives net::ERR_CACHE_MISS message

To Solve this Error in Webview Android, First Check the Permissions in Manifest.xml, if not define there,then define as like this. <uses-permission android:name="android.permission.INTERNET"/>

Why is it bad practice to call System.gc()?

GC efficiency relies on a number of heuristics. For instance, a common heuristic is that write accesses to objects usually occur on objects which were created not long ago. Another is that many objects are very short-lived (some objects will be used for a long time, but many will be discarded a few microseconds after their creation).

Calling System.gc() is like kicking the GC. It means: "all those carefully tuned parameters, those smart organizations, all the effort you just put into allocating and managing the objects such that things go smoothly, well, just drop the whole lot, and start from scratch". It may improve performance, but most of the time it just degrades performance.

To use System.gc() reliably(*) you need to know how the GC operates in all its fine details. Such details tend to change quite a bit if you use a JVM from another vendor, or the next version from the same vendor, or the same JVM but with slightly different command-line options. So it is rarely a good idea, unless you want to address a specific issue in which you control all those parameters. Hence the notion of "bad practice": that's not forbidden, the method exists, but it rarely pays off.

(*) I am talking about efficiency here. System.gc() will never break a correct Java program. It will neither conjure extra memory that the JVM could not have obtained otherwise: before throwing an OutOfMemoryError, the JVM does the job of System.gc(), even if as a last resort.

dlib installation on Windows 10

So basically I have been searching the solution for two days. I tried everything

  • Installing Cmake
  • Adding path
  • installing dlib from the links mentioned in the answers
  • Installing ## Heading ## numpy, scipy, matplotlib, pandas
  • etc etc etc


After installing MS VS C++ I ran command pip install dlib and it is working like a charm. BEST OF LUCK

Link to download Visual Studio C++

MongoDB: Is it possible to make a case-insensitive query?

Starting with MongoDB 3.4, the recommended way to perform fast case-insensitive searches is to use a Case Insensitive Index.

I personally emailed one of the founders to please get this working, and he made it happen! It was an issue on JIRA since 2009, and many have requested the feature. Here's how it works:

A case-insensitive index is made by specifying a collation with a strength of either 1 or 2. You can create a case-insensitive index like this:

  { city: 1 },
    collation: {
      locale: 'en',
      strength: 2

You can also specify a default collation per collection when you create them:

db.createCollection('cities', { collation: { locale: 'en', strength: 2 } } );

In either case, in order to use the case-insensitive index, you need to specify the same collation in the find operation that was used when creating the index or the collection:

  { city: 'new york' }
  { locale: 'en', strength: 2 }

This will return "New York", "new york", "New york" etc.

Other notes

  • The answers suggesting to use full-text search are wrong in this case (and potentially dangerous). The question was about making a case-insensitive query, e.g. username: 'bill' matching BILL or Bill, not a full-text search query, which would also match stemmed words of bill, such as Bills, billed etc.

  • The answers suggesting to use regular expressions are slow, because even with indexes, the documentation states:

    "Case insensitive regular expression queries generally cannot use indexes effectively. The $regex implementation is not collation-aware and is unable to utilize case-insensitive indexes."

    $regex answers also run the risk of user input injection.

Auto generate function documentation in Visual Studio

Visual Assist has a nice solution too, and is highly costumizable.

After tweaking it to generate doxygen-style comments, these two clicks would produce -

* Method:    FindTheFoo
* FullName:  FindTheFoo
* Access:    private 
* Qualifier:
* @param    int numberOfFoos
* @return   bool
private bool FindTheFoo(int numberOfFoos)


(Under default settings, its a bit different.)

Edit: The way to customize the 'document method' text is under VassistX->Visual Assist Options->Suggestions, select 'Edit VA Snippets', Language: C++, Type: Refactoring, then go to 'Document Method' and customize. The above example is generated by:


Cross-Origin Request Headers(CORS) with PHP headers

add this code in .htaccess

add custom authentication key's in header like app_key,auth_key..etc

Header set Access-Control-Allow-Origin "*"
Header set Access-Control-Allow-Headers: "customKey1,customKey2, headers, Origin, X-Requested-With, Content-Type, Accept, Authorization"

How to convert Nvarchar column to INT

Your CAST() looks correct.

Your CONVERT() is not correct. You are quoting the column as a string. You will want something like

CONVERT(INT, A.my_NvarcharColumn)

** notice without the quotes **

The only other reason why this could fail is if you have a non-numeric character in the field value or if it's out of range.

You can try something like the following to verify it's numeric and return a NULL if it's not:

  WHEN ISNUMERIC(A.my_NvarcharColumn) = 1 THEN CONVERT(INT, A.my_NvarcharColumn)
 END AS my_NvarcharColumn

How to download Xcode DMG or XIP file?

You can find the DMGs or XIPs for Xcode and other development tools on (requires Apple ID to login).

You must login to have a valid session before downloading anything below.

*(Newest on top. For each minor version (6.3, 5.1, etc.) only the latest revision is kept in the list.)

*With Xcode 12.2, Apple introduces the term “Release Candidate” (RC) which replaces “GM seed” and indicates this version is near final.

Xcode 12

  • 12.4 (requires a Mac with Apple silicon running macOS Big Sur 11 or later, or an Intel-based Mac running macOS Catalina 10.15.4 or later) (Latest as of 27-Jan-2021)

  • 12.3 (requires a Mac with Apple silicon running macOS Big Sur 11 or later, or an Intel-based Mac running macOS Catalina 10.15.4 or later)

  • 12.2

  • 12.1

  • 12.0.1 (Requires macOS 10.15.4 or later) (Latest as of 24-Sept-2020)

Xcode 11

Xcode 10 (unsupported for iTunes Connect)

  • 10.3 (Requires macOS 10.14.3 or later)
  • 10.2.1 (Requires macOS 10.14.3 or later)
  • 10.1 (Last version supporting macOS 10.13.6 High Sierra)
  • 10 (Subsequent versions were unsupported for iTunes Connect from March 2019)

Xcode 9

Xcode 8

Xcode 7

Xcode 6

Even Older Versions (unsupported for iTunes Connect)

trace a particular IP and port

tcptraceroute   xx.xx.xx.xx 9100

if you didn't find it you can install it

yum -y install tcptraceroute 


aptitude -y install tcptraceroute 

Xcode 10, Command CodeSign failed with a nonzero exit code

This worked for me :) I removed the certificate in keychain access settings. Go to Xcode and clean build the app. Now certificate is again created in keychain access and build gets succeeded with real device.

Use jQuery to change a second select list based on the first select list option

I built on sabithpocker's idea and made a more generalized version that lets you control more than one selectbox from a given trigger.

I assigned the selectboxes I wanted to be controlled the classname "switchable," and cloned them all like this:

$j(this).data('options',$j('select.switchable option').clone());

and used a specific naming convention for the switchable selects, which could also translate into classes. In my case, "category" and "issuer" were the select names, and "category_2" and "issuer_1" the class names.

Then I ran an $.each on the select.switchable groups, after making a copy of $(this) for use inside the function:

var that = this;
$j("select.switchable").each(function() { 
    var thisname = $j(this).attr('name');
    var theseoptions = $j(that).data('options').filter( '.' + thisname + '_' + id );

By using a classname on the ones you want to control, the function will safely ignore other selects elsewhere on the page (such as the last one in the example on Fiddle).

Here's a Fiddle with the complete code:

How do I add a delay in a JavaScript loop?

    var startIndex = 0;_x000D_
    var data = [1, 2, 3];_x000D_
    var timeout = 1000;_x000D_
    function functionToRun(i, length) {_x000D_
    (function forWithDelay(i, length, fn, delay) {_x000D_
      setTimeout(function() {_x000D_
        fn(i, length);_x000D_
        if (i < length) {_x000D_
          forWithDelay(i, length, fn, delay);_x000D_
      }, delay);_x000D_
    })(startIndex, data.length, functionToRun, timeout);

A modified version of Daniel Vassallo's answer, with variables extracted into parameters to make the function more reusable:

First let's define some essential variables:

var startIndex = 0;
var data = [1, 2, 3];
var timeout = 3000;

Next you should define the function you want to run. This will get passed i, the current index of the loop and the length of the loop, in case you need it:

function functionToRun(i, length) {

Self-executing version

(function forWithDelay(i, length, fn, delay) {
   setTimeout(function () {
      fn(i, length);
      if (i < length) {
         forWithDelay(i, length, fn, delay); 
  }, delay);
})(startIndex, data.length, functionToRun, timeout);

Functional version

function forWithDelay(i, length, fn, delay) {
   setTimeout(function () {
      fn(i, length);
      if (i < length) {
         forWithDelay(i, length, fn, delay); 
  }, delay);

forWithDelay(startIndex, data.length, functionToRun, timeout); // Lets run it

Google Chrome Full Black Screen

I still experience occasional black screens with latest Chrome 60 with GPU acceleration enabled by default (probably caused by lack of free memory for numerous tabs).

Sometimes it helps to kill GPU process in builtin Task manager (Shift+Esc) as @amit suggests. But sometimes this forces more Chrome windows to become black while some others may remain normal.

I've noticed that tabs headers and address bar of black windows remain funtional and tabs can be fully repaired just by dragging them out of black windows. But it's too tedious to do this one by one when their number is huge.

So here is quick completely restartless solution inspired by Merging windows of Google Chrome:

  • Add a new empty tab to black window (Ctrl+T)
  • Left-click the first tab in the window
  • Then hold the Shift key and left-click the right most tab just before the empty one
  • Drag all the selected tabs at once out of the black window
  • Close the black window with remaining single empty tab

Angular HTTP GET with TypeScript error http.get(...).map is not a function in [null]

The map you using here, is not the .map() in javascript, it's Rxjs map function which working on Observables in Angular...

So in that case you need to import it if you'd like to use map on the result data...

map(project: function(value: T, index: number): R, thisArg: any): Observable<R> Applies a given project function to each value emitted by the source Observable, and emits the resulting values as an Observable.

So simply import it like this:

import 'rxjs/add/operator/map';

How to restore to a different database in sql server?

You can create a new db then use the "Restore Wizard" enabling the Overwrite option or;

View the content;


note the logical names of the .mdf & .ldf from the results, then;

   MOVE 'LogicalNameForTheMDF' TO 'c:\MyTempCopy.mdf',
   MOVE 'LogicalNameForTheLDF' TO 'c:\MyTempCopy_log.ldf'

To create the database MyTempCopy with the contents of your.bak.

Example (restores a backup of a db called 'creditline' to 'MyTempCopy';

RESTORE FILELISTONLY FROM DISK='e:\mssql\backup\creditline.bak'


RESTORE DATABASE MyTempCopy FROM DISK='e:\mssql\backup\creditline.bak'
   MOVE 'CreditLine' TO 'e:\mssql\MyTempCopy.mdf',
   MOVE 'CreditLine_log' TO 'e:\mssql\MyTempCopy_log.ldf'

>RESTORE DATABASE successfully processed 186 pages in 0.010 seconds (144.970 MB/sec).

Git removing upstream from local repository

Using git version there is no "remove" command for remote. Use "rm" instead.

$ git remote rm upstream
$ git remote add upstream

or, as noted in the previous answer, set-url works.

I don't know when the command changed, but Ubuntu 12.04 shipped with

In Objective-C, how do I test the object type?

You would probably use

- (BOOL)isKindOfClass:(Class)aClass

This is a method of NSObject.

For more info check the NSObject documentation.

This is how you use this.

BOOL test = [self isKindOfClass:[SomeClass class]];

You might also try doing somthing like this

for(id element in myArray)
    NSLog(@"Is of type: %@", [element className]);
    NSLog(@"Is of type NSString?: %@", ([[element className] isMemberOfClass:[NSString class]])? @"Yes" : @"No");
    NSLog(@"Is a kind of NSString: %@", ([[element classForCoder] isSubclassOfClass:[NSString class]])? @"Yes" : @"No");    

Xcode 6 Storyboard the wrong size?

I had this issue in xcode 6 and there is a way to resolve the resize conflicts. If you select your view, at the bottom you will see an icon that looks like |-Δ-|. If you click on it, you're project will resize for different devices.

How to represent matrices in python


Using tuples instead of lists makes it marginally harder to change the data structure in unwanted ways.

If you are going to do extensive use of those, you are best off wrapping a true number array in a class, so you can define methods and properties on them. (Or, you could NumPy, SciPy, ... if you are going to do your processing with those libraries.)

How to remove specific substrings from a set of strings in Python?

if you delete something from list , u can use this way : (method sub is case sensitive)

new_list = []
old_list= ["ABCDEFG","HKLMNOP","QRSTUV"]

for data in old_list:
     new_list.append(re.sub("AB|M|TV", " ", data))

print(new_list) // output : [' CDEFG', 'HKL NOP', 'QRSTUV']

Converting camel case to underscore case in ruby

In case someone looking for case when he need to apply underscore to string with spaces and want to convert them to underscores as well you can use something like this

'your String will be converted To underscore'.parameterize.underscore

Or just use .parameterize('_') but keep in mind that this one is deprecated

'your String will be converted To underscore'.parameterize('_')

Remote debugging a Java application


  1. Start your remote java application with debugging options as said in above post.
  2. Configure Eclipse for remote debugging by specifying host and port.
  3. Start remote debugging in Eclipse and wait for connection to succeed.
  4. Setup breakpoint and debug.
  5. If you want to debug from start of application use suspend=y , this will keep remote application suspended until you connect from eclipse.

See Step by Step guide on Java remote debugging for full details.

How to ignore ansible SSH authenticity checking?

I found the answer, you need to set the environment variable ANSIBLE_HOST_KEY_CHECKING to False. For example:

ANSIBLE_HOST_KEY_CHECKING=False ansible-playbook ...

HTML 'td' width and height

The width attribute of <td> is deprecated in HTML 5.

Use CSS. e.g.

 <td style="width:100px">

in detail, like this:

<table >
    <td style="width:70%">January</td>
    <td style="width:30%">$100</td>

Accessing JSON elements

Another alternative way using get method with requests:

import requests
wjdata = requests.get('url').json()
print wjdata.get('data').get('current_condition')[0].get('temp_C')

MongoDB: update every document on one field

I have been using MongoDB .NET driver for a little over a month now. If I were to do it using .NET driver, I would use Update method on the collection object. First, I will construct a query that will get me all the documents I am interested in and do an Update on the fields I want to change. Update in Mongo only affects the first document and to update all documents resulting from the query one needs to use 'Multi' update flag. Sample code follows...

var collection = db.GetCollection("Foo");
var query = Query.GTE("No", 1); // need to construct in such a way that it will give all 20K //docs.
var update = Update.Set("timestamp", datetime.UtcNow);
collection.Update(query, update, UpdateFlags.Multi);

How to use target in location.href

Why not have a hidden anchor tag on the page with the target set as you need, then simulate clicking it when you need the pop out?

How can I simulate a click to an anchor tag?

This would work in the cases where the did not work

How to change default Anaconda python environment

Under Linux there is an easier way to set the default environment by modifying ~/.bashrc or ~/.bash_profile At the end you'll find something like

# added by Anaconda 2.1.0 installer
export PATH="~/anaconda/bin:$PATH"

Replace it with

# set python3 as default
export PATH="~/anaconda/envs/python3/bin:$PATH"

and thats all there is to it.

NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

Add the all tiles jars like(tiles-jsp,tiles-servlet,tiles-template,tiles-extras.tiles-core ) to your server lib folder and your application build path then it work if you using apache tailes with spring mvc application

What does "<>" mean in Oracle

It means not equal to

Should I use != or <> for not equal in TSQL?

Have a look at the link. It has detailed explanation of what to use for what.

Android Studio-No Module

Try first in Android Studio:

File -> Sync Project with Gradle Files

Clicking URLs opens default browser

The method boolean shouldOverrideUrlLoading(WebView view, String url) was deprecated in API 24. If you are supporting new devices you should use boolean shouldOverrideUrlLoading (WebView view, WebResourceRequest request).

You can use both by doing something like this:

    newsItem.setWebViewClient(new WebViewClient() {
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
            return true;
} else {
    newsItem.setWebViewClient(new WebViewClient() {
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return true;

How to assign text size in sp value using java code

When the accepted answer doesn't work (for example when dealing with Paint) you can use:

float spTextSize = 12;
float textSize = spTextSize * getResources().getDisplayMetrics().scaledDensity;

Initializing an Array of Structs in C#

I'd use a static constructor on the class that sets the value of a static readonly array.

public class SomeClass
   public readonly MyStruct[] myArray;

   public static SomeClass()
      myArray = { {"foo", "bar"},
                  {"boo", "far"}};

How do I resolve a HTTP 414 "Request URI too long" error?

An excerpt from the RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1:

The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line. POST is designed to allow a uniform method to cover the following functions:

  • Annotation of existing resources;
  • Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles;
  • Providing a block of data, such as the result of submitting a form, to a data-handling process;
  • Extending a database through an append operation.

How to read/write from/to file using Go?

Let's make a Go 1-compatible list of all the ways to read and write files in Go.

Because file API has changed recently and most other answers don't work with Go 1. They also miss bufio which is important IMHO.

In the following examples I copy a file by reading from it and writing to the destination file.

Start with the basics

package main

import (

func main() {
    // open input file
    fi, err := os.Open("input.txt")
    if err != nil {
    // close fi on exit and check for its returned error
    defer func() {
        if err := fi.Close(); err != nil {

    // open output file
    fo, err := os.Create("output.txt")
    if err != nil {
    // close fo on exit and check for its returned error
    defer func() {
        if err := fo.Close(); err != nil {

    // make a buffer to keep chunks that are read
    buf := make([]byte, 1024)
    for {
        // read a chunk
        n, err := fi.Read(buf)
        if err != nil && err != io.EOF {
        if n == 0 {

        // write a chunk
        if _, err := fo.Write(buf[:n]); err != nil {

Here I used os.Open and os.Create which are convenient wrappers around os.OpenFile. We usually don't need to call OpenFile directly.

Notice treating EOF. Read tries to fill buf on each call, and returns io.EOF as error if it reaches end of file in doing so. In this case buf will still hold data. Consequent calls to Read returns zero as the number of bytes read and same io.EOF as error. Any other error will lead to a panic.

Using bufio

package main

import (

func main() {
    // open input file
    fi, err := os.Open("input.txt")
    if err != nil {
    // close fi on exit and check for its returned error
    defer func() {
        if err := fi.Close(); err != nil {
    // make a read buffer
    r := bufio.NewReader(fi)

    // open output file
    fo, err := os.Create("output.txt")
    if err != nil {
    // close fo on exit and check for its returned error
    defer func() {
        if err := fo.Close(); err != nil {
    // make a write buffer
    w := bufio.NewWriter(fo)

    // make a buffer to keep chunks that are read
    buf := make([]byte, 1024)
    for {
        // read a chunk
        n, err := r.Read(buf)
        if err != nil && err != io.EOF {
        if n == 0 {

        // write a chunk
        if _, err := w.Write(buf[:n]); err != nil {

    if err = w.Flush(); err != nil {

bufio is just acting as a buffer here, because we don't have much to do with data. In most other situations (specially with text files) bufio is very useful by giving us a nice API for reading and writing easily and flexibly, while it handles buffering behind the scenes.

Note: The following code is for older Go versions (Go 1.15 and before). Things have changed. For the new way, take a look at this answer.

Using ioutil

package main

import (

func main() {
    // read the whole file at once
    b, err := ioutil.ReadFile("input.txt")
    if err != nil {

    // write the whole body at once
    err = ioutil.WriteFile("output.txt", b, 0644)
    if err != nil {

Easy as pie! But use it only if you're sure you're not dealing with big files.

Why does Java's hashCode() in String use 31 as a multiplier?

Bloch doesn't quite go into this, but the rationale I've always heard/believed is that this is basic algebra. Hashes boil down to multiplication and modulus operations, which means that you never want to use numbers with common factors if you can help it. In other words, relatively prime numbers provide an even distribution of answers.

The numbers that make up using a hash are typically:

  • modulus of the data type you put it into (2^32 or 2^64)
  • modulus of the bucket count in your hashtable (varies. In java used to be prime, now 2^n)
  • multiply or shift by a magic number in your mixing function
  • The input value

You really only get to control a couple of these values, so a little extra care is due.

How can I read large text files in Python, line by line, without loading it into memory?

I couldn't believe that it could be as easy as @john-la-rooy's answer made it seem. So, I recreated the cp command using line by line reading and writing. It's CRAZY FAST.

#!/usr/bin/env python3.6

import sys

with open(sys.argv[2], 'w') as outfile:
    with open(sys.argv[1]) as infile:
        for line in infile:

How to set different colors in HTML in one statement?

.rainbow {_x000D_
  background-image: -webkit-gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );_x000D_
  background-image: gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );_x000D_
  -webkit-background-clip: text;_x000D_
  background-clip: text;_x000D_
<h2><span class="rainbow">Rainbows are colorful and scalable and lovely</span></h2>

JSON formatter in C#?

There are already a bunch of great answers here that use Newtonsoft.JSON, but here's one more that uses JObject.Parse in combination with ToString(), since that hasn't been mentioned yet:

var jObj = Newtonsoft.Json.Linq.JObject.Parse(json);
var formatted = jObj.ToString(Newtonsoft.Json.Formatting.Indented);

How to modify PATH for Homebrew?

To avoid unnecessary duplication, I added the following to my ~/.bash_profile

case ":$PATH:" in
  *:/usr/local/bin:*) ;;     # do nothing if $PATH already contains /usr/local/bin
  *) PATH=/usr/local/bin:$PATH ;;  # in every other case, add it to the front


Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set()

If you are running your application just on localhost and it is not yet live, I believe it is very difficult to send mail using this.

Once you put your application online, I believe that this problem should be automatically solved. By the way,ini_set() helps you to change the values in php.ini during run time.

This is the same question as Failed to connect to mailserver at "localhost" port 25

also check this php mail function not working

Calculating average of an array list?>a).average()

How to change the project in GCP using CLI commands

Check your project by running gcloud config list Then gcloud config set "project name"

Java Best Practices to Prevent Cross Site Scripting

My preference is to encode all non-alphaumeric characters as HTML numeric character entities. Since almost, if not all attacks require non-alphuneric characters (like <, ", etc) this should eliminate a large chunk of dangerous output.

Format is &#N;, where N is the numeric value of the character (you can just cast the character to an int and concatenate with a string to get a decimal value). For example:

// java-ish pseudocode
StringBuffer safestrbuf = new StringBuffer(string.length()*4);
foreach(char c : string.split() ){  
  if( Character.isAlphaNumeric(c) ) safestrbuf.append(c);
  else safestrbuf.append(""+(int)symbol);

You will also need to be sure that you are encoding immediately before outputting to the browser, to avoid double-encoding, or encoding for HTML but sending to a different location.

Assign variable value inside if-statement

You can assign, but not declare, inside an if:

Try this:

int v; // separate declaration
if((v = someMethod()) != 0) return true;

Favorite Visual Studio keyboard shortcuts

Ctrl + R + W to display whitespace (great for tab or space enforcement).

Also, holding down Alt while selecting with the mouse will create a rectangular region.

Stop on first error

Maybe you want set -e:

This tells bash that it should exit the script if any statement returns a non-true return value. The benefit of using -e is that it prevents errors snowballing into serious issues when they could have been caught earlier. Again, for readability you may want to use set -o errexit.

Difference between ${} and $() in Bash

  1. $() means: "first evaluate this, and then evaluate the rest of the line".

    Ex :

    echo $(pwd)/myFile.txt

    will be interpreted as

    echo /my/path/myFile.txt

    On the other hand ${} expands a variable.


    echo ${MY_VAR}/myFile.txt

    will be interpreted as

    echo toto/myFile.txt
  2. Why can't I use it as bash$ while ((i=0;i<10;i++)); do echo $i; done

    I'm afraid the answer is just that the bash syntax for while just isn't the same as the syntax for for.

CSS rotation cross browser with jquery.animate()

CSS-Transforms are not possible to animate with jQuery, yet. You can do something like this:

function AnimateRotate(angle) {
    // caching the object for performance reasons
    var $elem = $('#MyDiv2');

    // we use a pseudo object for the animation
    // (starts from `0` to `angle`), you can name it as you want
    $({deg: 0}).animate({deg: angle}, {
        duration: 2000,
        step: function(now) {
            // in the step-callback (that is fired each step of the animation),
            // you can use the `now` paramter which contains the current
            // animation-position (`0` up to `angle`)
                transform: 'rotate(' + now + 'deg)'

You can read more about the step-callback here:

And, btw: you don't need to prefix css3 transforms with jQuery 1.7+


You can wrap this in a jQuery-plugin to make your life a bit easier:

$.fn.animateRotate = function(angle, duration, easing, complete) {
  return this.each(function() {
    var $elem = $(this);

    $({deg: 0}).animate({deg: angle}, {
      duration: duration,
      easing: easing,
      step: function(now) {
           transform: 'rotate(' + now + 'deg)'
      complete: complete || $.noop



I optimized it a bit to make the order of easing, duration and complete insignificant.

$.fn.animateRotate = function(angle, duration, easing, complete) {
  var args = $.speed(duration, easing, complete);
  var step = args.step;
  return this.each(function(i, e) {
    args.complete = $.proxy(args.complete, e);
    args.step = function(now) {
      $.style(e, 'transform', 'rotate(' + now + 'deg)');
      if (step) return step.apply(e, arguments);

    $({deg: 0}).animate({deg: angle}, args);

Update 2.1

Thanks to matteo who noted an issue with the this-context in the complete-callback. If fixed it by binding the callback with jQuery.proxy on each node.

I've added the edition to the code before from Update 2.

Update 2.2

This is a possible modification if you want to do something like toggle the rotation back and forth. I simply added a start parameter to the function and replaced this line:

$({deg: start}).animate({deg: angle}, args);

If anyone knows how to make this more generic for all use cases, whether or not they want to set a start degree, please make the appropriate edit.

The quite simple!

Mainly you've two ways to reach the desired result. But at the first, let's take a look on the arguments:

jQuery.fn.animateRotate(angle, duration, easing, complete)

Except of "angle" are all of them optional and fallback to the default jQuery.fn.animate-properties:

duration: 400
easing: "swing"
complete: function () {}


This way is the short one, but looks a bit unclear the more arguments we pass in.

$(node).animateRotate(90, function () {});
$(node).animateRotate(90, 1337, 'linear', function () {});


I prefer to use objects if there are more than three arguments, so this syntax is my favorit:

$(node).animateRotate(90, {
  duration: 1337,
  easing: 'linear',
  complete: function () {},
  step: function () {}

How to multiply values using SQL

Why are you grouping by? Do you mean order by?

SELECT player_name, player_salary, player_salary * 1.1 AS NewSalary
FROM players
ORDER BY player_salary, player_name;

How to prepend a string to a column value in MySQL?

You can use the CONCAT function to do that:

UPDATE tbl SET col=CONCAT('test',col);

If you want to get cleverer and only update columns which don't already have test prepended, try

UPDATE tbl SET col=CONCAT('test',col)
WHERE col NOT LIKE 'test%';

How do I use two submit buttons, and differentiate between which one was used to submit the form?

You can use it as follows,


<input type="submit" name="save" class="noborder" id="save" value="Save" alt="Save" 
tabindex="4" />



<input type="submit" name="publish" class="noborder" id="publish" value="Publish" 
alt="Publish" tabindex="5" />


And in PHP,

   //Save Code
else if($_POST['publish'])
   //Publish Code

How to start/stop/restart a thread in Java?

Review java.lang.Thread.

To start or restart (once a thread is stopped, you can't restart that same thread, but it doesn't matter; just create a new Thread instance):

// Create your Runnable instance
Task task = new Task(...);

// Start a thread and run your Runnable
Thread t = new Thread(task);

To stop it, have a method on your Task instance that sets a flag to tell the run method to exit; returning from run exits the thread. If your calling code needs to know the thread really has stopped before it returns, you can use join:

// Tell Task to stop

// Wait for it to do so

Regarding restarting: Even though a Thread can't be restarted, you can reuse your Runnable instance with a new thread if it has state and such you want to keep; that comes to the same thing. Just make sure your Runnable is designed to allow multiple calls to run.

What is exactly the base pointer and stack pointer? To what do they point?

EDIT: For a better description, see x86 Disassembly/Functions and Stack Frames in a WikiBook about x86 assembly. I try to add some info you might be interested in using Visual Studio.

Storing the caller EBP as the first local variable is called a standard stack frame, and this may be used for nearly all calling conventions on Windows. Differences exist whether the caller or callee deallocates the passed parameters, and which parameters are passed in registers, but these are orthogonal to the standard stack frame problem.

Speaking about Windows programs, you might probably use Visual Studio to compile your C++ code. Be aware that Microsoft uses an optimization called Frame Pointer Omission, that makes it nearly impossible to do walk the stack without using the dbghlp library and the PDB file for the executable.

This Frame Pointer Omission means that the compiler does not store the old EBP on a standard place and uses the EBP register for something else, therefore you have hard time finding the caller EIP without knowing how much space the local variables need for a given function. Of course Microsoft provides an API that allows you to do stack-walks even in this case, but looking up the symbol table database in PDB files takes too long for some use cases.

To avoid FPO in your compilation units, you need to avoid using /O2 or need to explicitly add /Oy- to the C++ compilation flags in your projects. You probably link against the C or C++ runtime, which uses FPO in the Release configuration, so you will have hard time to do stack walks without the dbghlp.dll.

Git for beginners: The definitive practical guide

Git Magic is all you'll ever need. Guaranteed or your money back!

Detect if an input has text in it using CSS -- on a page I am visiting and do not control?

Basically what everybody is looking for is:


    &:invalid{ color: red; border-color: red; box-shadow: 0 0 6px red;}
    &:placeholder-shown{ border-color: green; box-shadow: 0 0 8px green;}

Pure CSS:

input:focus:required:invalid{ color: red; border-color: red; box-shadow: 0 0 6px red;}
input:focus:required:placeholder-shown{ border-color: green; box-shadow: 0 0 8px green;}

Continue For loop

You can use a GoTo:


    '... do stuff your loop will be doing

    ' skip to the end of the loop if necessary:
    If <condition-to-go-to-next-iteration> Then GoTo ContinueLoop 

    '... do other stuff if the condition is not met


A more useful statusline in vim?


Note vim-airline is gaining some traction as the new vimscript option as powerline has gone python.

Seems powerline is where it is at these days:-

Normal status line


Customised status lines for other plugins (e.g. ctrlp)


Replacing NULL with 0 in a SQL server query

You can use both of these methods but there are differences:

SELECT ISNULL(col1, 0 ) FROM table1
SELECT COALESCE(col1, 0 ) FROM table1

Comparing COALESCE() and ISNULL():

  1. The ISNULL function and the COALESCE expression have a similar purpose but can behave differently.

  2. Because ISNULL is a function, it is evaluated only once. As described above, the input values for the COALESCE expression can be evaluated multiple times.

  3. Data type determination of the resulting expression is different. ISNULL uses the data type of the first parameter, COALESCE follows the CASE expression rules and returns the data type of value with the highest precedence.

  4. The NULLability of the result expression is different for ISNULL and COALESCE. The ISNULL return value is always considered NOT NULLable (assuming the return value is a non-nullable one) whereas COALESCE with non-null parameters is considered to be NULL. So the expressions ISNULL(NULL, 1) and COALESCE(NULL, 1) although equivalent have different nullability values. This makes a difference if you are using these expressions in computed columns, creating key constraints or making the return value of a scalar UDF deterministic so that it can be indexed as shown in the following example.

-- This statement fails because the PRIMARY KEY cannot accept NULL values -- and the nullability of the COALESCE expression for col2 -- evaluates to NULL.

    col1 integer NULL, 
    col2 AS COALESCE(col1, 0) PRIMARY KEY, 
    col3 AS ISNULL(col1, 0) 

-- This statement succeeds because the nullability of the -- ISNULL function evaluates AS NOT NULL.

    col1 integer NULL, 
    col2 AS COALESCE(col1, 0), 
    col3 AS ISNULL(col1, 0) PRIMARY KEY 
  1. Validations for ISNULL and COALESCE are also different. For example, a NULL value for ISNULL is converted to int whereas for COALESCE, you must provide a data type.

  2. ISNULL takes only 2 parameters whereas COALESCE takes a variable number of parameters.

    if you need to know more here is the full document from msdn.

Iterate a certain number of times without storing the iteration number anywhere

for word in ['hello'] * 2:
    print word

It's not idiomatic Python, but neither is what you're trying to do.

Foreach Control in form, how can I do something to all the TextBoxes in my Form?

foreach (Control X in this.Controls)
  if (X is TextBox)
    (X as TextBox).Text = string.Empty;

How can I see the raw SQL queries Django is running?

No other answer covers this method, so:

I find by far the most useful, simple, and reliable method is to ask your database. For example on Linux for Postgres you might do:

sudo su postgres
tail -f /var/log/postgresql/postgresql-8.4-main.log

Each database will have slightly different procedure. In the database logs you'll see not only the raw SQL, but any connection setup or transaction overhead django is placing on the system.

python JSON object must be str, bytes or bytearray, not 'dict

You are passing a dictionary to a function that expects a string.

This syntax:

{"('Hello',)": 6, "('Hi',)": 5}

is both a valid Python dictionary literal and a valid JSON object literal. But loads doesn't take a dictionary; it takes a string, which it then interprets as JSON and returns the result as a dictionary (or string or array or number, depending on the JSON, but usually a dictionary).

If you pass this string to loads:

'''{"('Hello',)": 6, "('Hi',)": 5}'''

then it will return a dictionary that looks a lot like the one you are trying to pass to it.

You could also exploit the similarity of JSON object literals to Python dictionary literals by doing this:

json.loads(str({"('Hello',)": 6, "('Hi',)": 5}))

But in either case you would just get back the dictionary that you're passing in, so I'm not sure what it would accomplish. What's your goal?

What does 'corrupted double-linked list' mean

A coworker got this error and found out that somewhere int the code he did this mistake on an element of the list:

 std::string listElement = listElement = someObject.getName();

obviously instead of :

 std::string listElement = someObject.getName();

It seems unrelated, but the error was here at every run, we could reproduce it after cleaning everything, and changing only this line solved the problem.

Hope it helps someone one day....

python list by value not by reference

I found that we can use extend() to implement the function of copy()

a=['help', 'copyright', 'credits', 'license']
b = []

How can I keep my branch up to date with master with git?

Assuming you're fine with taking all of the changes in master, what you want is:

git checkout <my branch>

to switch the working tree to your branch; then:

git merge master

to merge all the changes in master with yours.

TypeError: can't pickle _thread.lock objects

You need to change from queue import Queue to from multiprocessing import Queue.

The root reason is the former Queue is designed for threading module Queue while the latter is for multiprocessing.Process module.

For details, you can read some source code or contact me!

XAMPP: Couldn't start Apache (Windows 10)

enter image description here

Change the port number which port are available in your system By following ways

1. First open the Apache “httpd.conf” file:

Listen 80
ServerName localhost:80


Listen 8080
ServerName localhost:8080

2. Open httpd-ssl.conf:

Listen 443
<VirtualHost _default_:443>


Listen 441
<VirtualHost _default_:441>

3. Follow the trick. Now “Start” Apache and if everything goes well, your Apache server should start up.

Check if selected dropdown value is empty using jQuery

You can try this also-

if( !$('#EventStartTimeMin').val() ) {
// do something

Return list of items in list greater than some value

Use filter (short version without doing a function with lambda, using __le__):

j2 = filter((5).__le__, j)

Example (python 3):

>>> j=[4,5,6,7,1,3,7,5]
>>> j2 = filter((5).__le__, j)
>>> j2
<filter object at 0x000000955D16DC18>
>>> list(j2)
[5, 6, 7, 7, 5]

Example (python 2):

>>> j=[4,5,6,7,1,3,7,5]
>>> j2 = filter((5).__le__, j)
>>> j2
[5, 6, 7, 7, 5]

Use __le__ i recommend this, it's very easy, __le__ is your friend

If want to sort it to desired output (both versions):

>>> j=[4,5,6,7,1,3,7,5]
>>> j2 = filter((5).__le__, j)
>>> sorted(j2)
[5, 5, 6, 7, 7]

Use sorted


>>> from timeit import timeit
>>> timeit(lambda: [i for i in j if i >= 5]) # Michael Mrozek
>>> timeit(lambda: filter(lambda x: x >= 5, j)) # Justin Ardini
>>> timeit(lambda: filter((5).__le__, j)) # Mine

So Justin wins!!

With number=1:

>>> from timeit import timeit
>>> timeit(lambda: [i for i in j if i >= 5],number=1) # Michael Mrozek
>>> timeit(lambda: filter(lambda x: x >= 5, j),number=1) # Justin Ardini
>>> timeit(lambda: filter((5).__le__, j),number=1) # Mine

So Michael wins!!

>>> from timeit import timeit
>>> timeit(lambda: [i for i in j if i >= 5],number=10) # Michael Mrozek
>>> timeit(lambda: filter(lambda x: x >= 5, j),number=10) # Justin Ardini
>>> timeit(lambda: filter((5).__le__, j),number=10) # Mine

So Justin wins again!!

What is an idiomatic way of representing enums in Go?

I am sure we have a lot of good answers here. But, I just thought of adding the way I have used enumerated types

package main

import "fmt"

type Enum interface {
    name() string
    ordinal() int
    values() *[]string

type GenderType uint

const (
    MALE = iota

var genderTypeStrings = []string{

func (gt GenderType) name() string {
    return genderTypeStrings[gt]

func (gt GenderType) ordinal() int {
    return int(gt)

func (gt GenderType) values() *[]string {
    return &genderTypeStrings

func main() {
    var ds GenderType = MALE
    fmt.Printf("The Gender is %s\n",

This is by far one of the idiomatic ways we could create Enumerated types and use in Go.


Adding another way of using constants to enumerate

package main

import (

const (
    // UNSPECIFIED logs nothing
    UNSPECIFIED Level = iota // 0 :
    // TRACE logs everything
    TRACE // 1
    // INFO logs Info, Warnings and Errors
    INFO // 2
    // WARNING logs Warning and Errors
    WARNING // 3
    // ERROR just logs Errors
    ERROR // 4

// Level holds the log level.
type Level int

func SetLogLevel(level Level) {
    switch level {
    case TRACE:

    case INFO:

    case WARNING:
    case ERROR:



func main() {



How can I format a number into a string with leading zeros?

For interpolated strings:

$"Int value: {someInt:D4} or {someInt:0000}. Float: {someFloat: 00.00}"

Func delegate with no return type

All Func delegates return something; all the Action delegates return void.

Func<TResult> takes no arguments and returns TResult:

public delegate TResult Func<TResult>()

Action<T> takes one argument and does not return a value:

public delegate void Action<T>(T obj)

Action is the simplest, 'bare' delegate:

public delegate void Action()

There's also Func<TArg1, TResult> and Action<TArg1, TArg2> (and others up to 16 arguments). All of these (except for Action<T>) are new to .NET 3.5 (defined in System.Core).

simple HTTP server in Java using only Java SE API

Once upon a time I was looking for something similar - a lightweight yet fully functional HTTP server that I could easily embed and customize. I found two types of potential solutions:

  • Full servers that are not all that lightweight or simple (for an extreme definition of lightweight.)
  • Truly lightweight servers that aren't quite HTTP servers, but glorified ServerSocket examples that are not even remotely RFC-compliant and don't support commonly needed basic functionality.

So... I set out to write JLHTTP - The Java Lightweight HTTP Server.

You can embed it in any project as a single (if rather long) source file, or as a ~50K jar (~35K stripped) with no dependencies. It strives to be RFC-compliant and includes extensive documentation and many useful features while keeping bloat to a minimum.

Features include: virtual hosts, file serving from disk, mime type mappings via standard mime.types file, directory index generation, welcome files, support for all HTTP methods, conditional ETags and If-* header support, chunked transfer encoding, gzip/deflate compression, basic HTTPS (as provided by the JVM), partial content (download continuation), multipart/form-data handling for file uploads, multiple context handlers via API or annotations, parameter parsing (query string or x-www-form-urlencoded body), etc.

I hope others find it useful :-)

Manually Set Value for FormBuilder Control

You can use the following methods to update the value of a reactive form control. Any of the following method will suit for your need.

Methods using setValue()


Methods using patchValue()


Last method will loop thorough all the controls in the form so it is not preferred when updating single control

You can use any of the method inside the event handler

deptSelected(selected: { id: string; text: string }) {
     // any of the above method can be added here

You can update multiple controls in the form group if required using the

this.form.patchValue({"dept":, "description":"description value"});

How to change package name in android studio?

Another good method is: First create a new package with the desired name by right clicking on the java folder -> new -> package.

Then, select and drag all your classes to the new package. Android Studio will refactor the package name everywhere.

Finally, delete the old package.

or Look into this post

Qt jpg image display

  1. Add Label (a QLabel) to the dialog where you want to show the image. This QLabel will actually display the image. Resize it to the size you want the image to appear.

  2. Add the image to your resources in your project.

  3. Now go into QLabel properties and select the image you added to resources for pixmap property. Make sure to check the next property scaledContents to shrink the image in the size you want to see it.

That's all, the image will now show up.

Font size relative to the user's screen resolution?

I've created a variant of

where you can set min and max text size in relation of min and max size of box that you want "check" size. In addition you can check size of dom element different than box where you want apply text size.

You resize text between 19px and 25px on #size-2 element, based on 500px and 960px width of #size-2 element


You resize text between 13px and 20px on #size-1 element, based on 500px and 960px width of body element


complete code are there

function inRange (x,min,max) {
    return Math.min(Math.max(x, min), max);

function resizeTextInRange(minW,maxW,textMinS,textMaxS, elementApply, elementCheck=0) {


    var ww = $(elementCheck).width();
    var difW = maxW-minW;
    var difT = textMaxS- textMinS;
    var rapW = (ww-minW);
    var out=(difT/100)*(rapW/(difW/100))+textMinS;
    var normalizedOut = inRange(out, textMinS, textMaxS);



$(function () {
    $(window).resize(function () {

Get the content of a sharepoint folder with Excel VBA

Try mapping the sharepoint library to a drive letter in windows. Then select the drive and path in your code.

How do I do an insert with DATETIME now inside of SQL server mgmt studioÜ

Just use GETDATE() or GETUTCDATE() (if you want to get the "universal" UTC time, instead of your local server's time-zone related time).

INSERT INTO [Business]
           (0, 'Joe', 'Thomas', 
           GETDATE(),  <LastUpdatedBy, nvarchar(50),>)

How to upgrade docker container after its image changed

This is something I've also been struggling with for my own images. I have a server environment from which I create a Docker image. When I update the server, I'd like all users who are running containers based on my Docker image to be able to upgrade to the latest server.

Ideally, I'd prefer to generate a new version of the Docker image and have all containers based on a previous version of that image automagically update to the new image "in place." But this mechanism doesn't seem to exist.

So the next best design I've been able to come up with so far is to provide a way to have the container update itself--similar to how a desktop application checks for updates and then upgrades itself. In my case, this will probably mean crafting a script that involves Git pulls from a well-known tag.

The image/container doesn't actually change, but the "internals" of that container change. You could imagine doing the same with apt-get, yum, or whatever is appropriate for you environment. Along with this, I'd update the myserver:latest image in the registry so any new containers would be based on the latest image.

I'd be interested in hearing whether there is any prior art that addresses this scenario.

Global Git ignore

You should create an exclude file for this. Check out this gist which is pretty self explanatory.

To address your question though, you may need to either de-index the .tmproj file (if you've already added it to the index) with git rm --cached path/to/.tmproj, or git add and commit your .gitignore file.

Visual Studio Code: format is not using indent settings

The number of spaces to use for formatting is taken from a different location. I'm using version 1.0 and this is what I've done to fix it (I'm assuming your using spaces instead of tabs):

At the bottom of the editor on the right hand click "Spaces: #":

status bar on the right

Then a menu will appear up top. Select "Indent Using Spaces":

select indentation type

Finally you can select by how many spaces you want your files to be indented.

select tab size

The next time you format a file you should be able to get the spacing you configured.

Java ElasticSearch None of the configured nodes are available

Since most of the ansswers seem to be outdated here is the setting that worked for me:

  • Elasticsearch-Version: 7.2.0 (OSS) running on Docker
  • Java-Version: JDK-11

elasticsearch.yml: production node1
transport.tcp.port: 9300
cluster.initial_master_nodes: node1


client = new PreBuiltTransportClient(Settings.builder().put("", "production").build());
client.addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9300));

Since PreBuiltTransportClient is deprecated you should use RestHighLevelClient for Elasticsearch-Version 7.3.0:

How to get form values in Symfony2 controller

If you have extra fields in the form that not defined in Entity , $form->getData() doesn't work , one way could be this :


Or :


How to add include path in Qt Creator?

For anyone completely new to Qt Creator like me, you can modify your project's .pro file from within Qt Creator:

enter image description here

Just double-click on "your project name".pro in the Projects window and add the include path at the bottom of the .pro file like I've done.

ACCESS_FINE_LOCATION AndroidManifest Permissions Not Being Granted

I was having the same problem and could not figure out what I was doing wrong. Turns out, the auto-complete for Android Studio was changing the text to either all caps or all lower case (depending on whether I typed in upper case or lower cast words before the auto-complete). The OS was not registering the name due to this issue and I would get the error regarding a missing permission. As stated above, ensure your permissions are labeled correctly:


<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />


<uses-permission android:name="ANDROID.PERMISSION.ACCESS_FINE_LOCATION" />


<uses-permission android:name="android.permission.access_fine_location" />

Though this may seem trivial, its easy to overlook.

If there is some setting to make permissions non-case-sensitive, please add a comment with the instructions. Thank you!

Sorting Python list based on the length of the string

When you pass a lambda to sort, you need to return an integer, not a boolean. So your code should instead read as follows:

xs.sort(lambda x,y: cmp(len(x), len(y)))

Note that cmp is a builtin function such that cmp(x, y) returns -1 if x is less than y, 0 if x is equal to y, and 1 if x is greater than y.

Of course, you can instead use the key parameter:

xs.sort(key=lambda s: len(s))

This tells the sort method to order based on whatever the key function returns.

EDIT: Thanks to balpha and Ruslan below for pointing out that you can just pass len directly as the key parameter to the function, thus eliminating the need for a lambda:


And as Ruslan points out below, you can also use the built-in sorted function rather than the list.sort method, which creates a new list rather than sorting the existing one in-place:

print(sorted(xs, key=len))

How do I generate a random number between two variables that I have stored?

If you have a C++11 compiler you can prepare yourself for the future by using c++'s pseudo random number faculties:

//make sure to include the random number generators and such
#include <random>
//the random device that will seed the generator
std::random_device seeder;
//then make a mersenne twister engine
std::mt19937 engine(seeder());
//then the easy part... the distribution
std::uniform_int_distribution<int> dist(min, max);
//then just generate the integer like this:
int compGuess = dist(engine);

That might be slightly easier to grasp, being you don't have to do anything involving modulos and crap... although it requires more code, it's always nice to know some new C++ stuff...

Hope this helps - Luke

How do I remove a MySQL database?

From the MySQL prompt:

mysql> drop database <db_name>;

Can't type in React input text field

i'm also facing that problem now solved.Give the onChange to the searchTool. then that problem will solve for you.

Is there a reason for C#'s reuse of the variable in a foreach?

The compiler declares the variable in a way that makes it highly prone to an error that is often difficult to find and debug, while producing no perceivable benefits.

Your criticism is entirely justified.

I discuss this problem in detail here:

Closing over the loop variable considered harmful

Is there something you can do with foreach loops this way that you couldn't if they were compiled with an inner-scoped variable? or is this just an arbitrary choice that was made before anonymous methods and lambda expressions were available or common, and which hasn't been revised since then?

The latter. The C# 1.0 specification actually did not say whether the loop variable was inside or outside the loop body, as it made no observable difference. When closure semantics were introduced in C# 2.0, the choice was made to put the loop variable outside the loop, consistent with the "for" loop.

I think it is fair to say that all regret that decision. This is one of the worst "gotchas" in C#, and we are going to take the breaking change to fix it. In C# 5 the foreach loop variable will be logically inside the body of the loop, and therefore closures will get a fresh copy every time.

The for loop will not be changed, and the change will not be "back ported" to previous versions of C#. You should therefore continue to be careful when using this idiom.

How to SELECT based on value of another SELECT

SELECT, x.summary, (x.summary / COUNT(*)) as percents_of_total
FROM tbl t
(SELECT name, SUM(value) as summary
FROM tbl
WHERE year BETWEEN 2000 AND 2001
GROUP BY name) x ON =
GROUP BY, x.summary

JSON serialization/deserialization in ASP.Net Core

You can use Newtonsoft.Json, it's a dependency of Microsoft.AspNet.Mvc.ModelBinding which is a dependency of Microsoft.AspNet.Mvc. So, you don't need to add a dependency in your project.json.

#using Newtonsoft.Json

Note, using a WebAPI controller you don't need to deal with JSON.

UPDATE ASP.Net Core 3.0

Json.NET has been removed from the ASP.NET Core 3.0 shared framework.

You can use the new JSON serializer layers on top of the high-performance Utf8JsonReader and Utf8JsonWriter. It deserializes objects from JSON and serializes objects to JSON. Memory allocations are kept minimal and includes support for reading and writing JSON with Stream asynchronously.

To get started, use the JsonSerializer class in the System.Text.Json.Serialization namespace. See the documentation for information and samples.

To use Json.NET in an ASP.NET Core 3.0 project:


Read Json.NET support in Migrate from ASP.NET Core 2.2 to 3.0 Preview 2 for more information.

Nginx: Job for nginx.service failed because the control process exited

May come in handy to check syntax of Nginx's configuration files by running:

nginx -t -c /etc/nginx/nginx.conf

Replacing Pandas or Numpy Nan with a None to use with MysqlDB

@bogatron has it right, you can use where, it's worth noting that you can do this natively in pandas:

df1 = df.where(pd.notnull(df), None)

Note: this changes the dtype of all columns to object.


In [1]: df = pd.DataFrame([1, np.nan])

In [2]: df
0   1
1 NaN

In [3]: df1 = df.where(pd.notnull(df), None)

In [4]: df1
0     1
1  None

Note: what you cannot do recast the DataFrames dtype to allow all datatypes types, using astype, and then the DataFrame fillna method:

df1 = df.astype(object).replace(np.nan, 'None')

Unfortunately neither this, nor using replace, works with None see this (closed) issue.

As an aside, it's worth noting that for most use cases you don't need to replace NaN with None, see this question about the difference between NaN and None in pandas.

However, in this specific case it seems you do (at least at the time of this answer).

What are the retransmission rules for TCP?

What exactly are the rules for requesting retransmission of lost data?

The receiver does not request the retransmission. The sender waits for an ACK for the byte-range sent to the client and when not received, resends the packets, after a particular interval. This is ARQ (Automatic Repeat reQuest). There are several ways in which this is implemented.

Stop-and-wait ARQ
Go-Back-N ARQ
Selective Repeat ARQ

are detailed in the RFC 3366.

At what time frequency are the retransmission requests performed?

The retransmissions-times and the number of attempts isn't enforced by the standard. It is implemented differently by different operating systems, but the methodology is fixed. (One of the ways to fingerprint OSs perhaps?)

The timeouts are measured in terms of the RTT (Round Trip Time) times. But this isn't needed very often due to Fast-retransmit which kicks in when 3 Duplicate ACKs are received.

Is there an upper bound on the number?

Yes there is. After a certain number of retries, the host is considered to be "down" and the sender gives up and tears down the TCP connection.

Is there functionality for the client to indicate to the server to forget about the whole TCP segment for which part went missing when the IP packet went missing?

The whole point is reliable communication. If you wanted the client to forget about some part, you wouldn't be using TCP in the first place. (UDP perhaps?)

how to append a css class to an element by javascript?

classList is a convenient alternative to accessing an element's list of classes.. see

Not supported in IE < 10

CSS selector for text input fields?

As @Amir posted above, the best way nowadays – cross-browser and leaving behind IE6 – is to use

[type=text] {}

Nobody mentioned lower CSS specificity (why is that important?) so far, [type=text] features 0,0,1,0 instead of 0,0,1,1 with input[type=text].

Performance-wise there's no negative impact at all any more.

normalize v4.0.0 just released with lowered selector specificity.

How to install SQL Server Management Studio 2012 (SSMS) Express?

Easiest way to install MSSQL 2012 MS SQL INSTALLATION

Here i am showing the easiest way to install ms sql 2012.

My opinion is the installation will be easier with windows 8.1 rather than windows 7.

This is my personnal opinion only.

We can install in windows 7 as well.

The steps to be followed:

Download any one of the link using the following URL



Right click on .exe file and run it

We should leave everything default while installing.

During installation, there will be 2 options:

1)If you are New user,then click on new sql-server stand alone application.

2)If you have already MS SQL application then you can upgrade by using the other option.

Then accept the Licence terms and click Next.

Now you will move on to Product Updates and press next then Setup support rules.

After this Feature selection.According to me we can check all the boxes except localdb.

Next it will take you to Instance Configuration where you should select Named Instance as


Then go to Server Configuration and press next.

Now Database engine configuration:

Authentication Mode:we can click on any one that is windows authentication mode or mixed.

Windows authentication mode (default for windows).

Mixed authentication mode:then should create username and password.

Then move on Error reporting,we can move further by clicking next to install process.

Finally we can see the Complete windows by showing the products added .

We can close and run the MSSQL server.

I hope it's useful.



Check string for nil & empty

Swift 3 This works well to check if the string is really empty. Because isEmpty returns true when there's a whitespace.

extension String {
    func isEmptyAndContainsNoWhitespace() -> Bool {
        guard self.isEmpty, self.trimmingCharacters(in: .whitespaces).isEmpty
            else {
               return false
        return true


let myString = "My String"
myString.isEmptyAndContainsNoWhitespace() // returns false

let myString = ""
myString.isEmptyAndContainsNoWhitespace() // returns true

let myString = " "
myString.isEmptyAndContainsNoWhitespace() // returns false

Using json_encode on objects in PHP (regardless of scope)

I usually include a small function in my objects which allows me to dump to array or json or xml. Something like:

public function exportObj($method = 'a')
     if($method == 'j')
         return json_encode(get_object_vars($this));
         return get_object_vars($this);

either way, get_object_vars() is probably useful to you.