Programs & Examples On #As3crypto

CSS to prevent child element from inheriting parent styles

Can't you style the forms themselves? Then, style the divs accordingly.

    /* styles */

You can always overrule inherited styles by making it important:

    /* styles */ !important

Transform hexadecimal information to binary using a Linux command

As @user786653 suggested, use the xxd(1) program:

xxd -r -p input.txt output.bin

Best way to do nested case statement logic in SQL Server

This example might help you, the picture shows how SQL case statement will look like when there are if and more than one inner if loops

enter image description here

What bitrate is used for each of the youtube video qualities (360p - 1080p), in regards to flowplayer?

Looking at this official google link: Youtube Live encoder settings, bitrates and resolutions they have this table:

                   240p       360p        480p        720p        1080p
Resolution      426 x 240   640 x 360   854x480     1280x720    1920x1080
Video Bitrates                   
Maximum         700 Kbps    1000 Kbps   2000 Kbps   4000 Kbps   6000 Kbps
Recommended     400 Kbps    750 Kbps    1000 Kbps   2500 Kbps   4500 Kbps
Minimum         300 Kbps    400 Kbps    500 Kbps    1500 Kbps   3000 Kbps

It would appear as though this is the case, although the numbers dont sync up to the google table above:

// the bitrates, video width and file names for this clip
      bitrates: [
        { url: "bbb-800.mp4", width: 480, bitrate: 800 }, //360p video
        { url: "bbb-1200.mp4", width: 720, bitrate: 1200 }, //480p video
        { url: "bbb-1600.mp4", width: 1080, bitrate: 1600 } //720p video
      ], no protocol

Try instead of db.parse(xml):

Document doc = db.parse(new InputSource(new StringReader(**xml**)));

Replace invalid values with None in Pandas DataFrame

df = pd.DataFrame(['-',3,2,5,1,-5,-1,'-',9])
df = df.where(df!='-', None)

How can I make Jenkins CI with Git trigger on pushes to master?

Above answers are correct but i am addressing to them who are newbie here for their simplicity

especially for setting build trigger for pipeline:

Consider you have two Github branches: 1.master,, and Jenkinsfile (where pipeline script is written) and other files are available on each branch

Configure new Pipeline project (for dev branch)

##1.Code integration with git-plugin and cron based approach Prerequisite git plugin should be installed and configure it with your name and email

  1. General section.Check checkbox - 'This project is parameterized’ and add Name-SBRANCH Default Value-'refs/remotes/origin/dev'
  2. Build triggers section" Check checkbox - 'Poll SCM' and schedule as per need for checking commits e.g. '*/1 * * * *' to check every minute
  3. Pipeline definition section.Select - Pipeline script from SCM—> select git—> addRepository URL—>add git credentials—> choose advanced—> add Name- origin, RefSpec- '+refs/heads/dev:refs/remotes/origin/dev'(dev is github branch )—> Branches to build - ${SBRANCH} (Parameter name from ref 1st point)—> Script Path—> Jenkinsfile —> Uncheck Lightweightcheckout
  4. Apply—> save

##2.Code integration: github-plugin and webhook approach Prerequisite Github plugin should be installed and Github server should be configured, connection should be tested if not consider following configuration

Configure Github plugin with account on Jenkins

GitHub section Add Github server if not present API URL: Credentials: Add secret text (Click add button: select type secret text) with value Personal Access Token (Generate it from your Github accounts—> settings—> developer setting—> personal access token—> add token—> check scopes—> copy the token) Test Connection—> Check whether it is connected to your Github account or not Check checkbox with Manage Hooks In advance sub-section just select previous credential for 'shared secret'

Add webhook if not added to your repository by

  1. Go to Github Repository setting —> add webhook—> add URL
  2. Or if you don't have Public_IP use ngrok. Install, authenticate, get public IP from command ./ngrok http 80(use your jenkins_port) then add webhook —> add URL http://Ngrok_IP/github-webhook/
  3. Test it by delivering payload from webhook page and check whether you get 200 status or not.

If you have Github Pull requests plugin configure it also with published Jenkins URL.

  1. General section.Check checkbox - 'Github project' add project URL -(github link ending with '.git/')
  2. General section.Check checkbox - 'This project is parameterized' and add Name-SBRANCH Default Value-'refs/remotes/origin/dev'
  3. Build triggers.section.Check checkbox - 'GitHub hook trigger for GITScm polling'
  4. Pipeline def'n section: Select - Pipeline script from SCM—> select git—> addRepository URL—> add git credentials—>choose advanced —>add Name- origin, RefSpec- '+refs/heads/dev:refs/remotes/origin/dev' (dev is github branch ) —> Branches to build - ${SBRANCH} (Parameter name from ref point)—> Script Path—> Jenkinsfile—> Uncheck Lightweightcheckout
  5. Apply—> save

Setting PayPal return URL and making it auto return?

You have to enable auto return in your PayPal account, otherwise it will ignore the return field.

From the documentation (updated to reflect new layout Jan 2019):

Auto Return is turned off by default. To turn on Auto Return:

  1. Log in to your PayPal account at or The My Account Overview page appears.
  2. Click the gear icon top right. The Profile Summary page appears.
  3. Click the My Selling Preferences link in the left column.
  4. Under the Selling Online section, click the Update link in the row for Website Preferences. The Website Payment Preferences page appears
  5. Under Auto Return for Website Payments, click the On radio button to enable Auto Return.
  6. In the Return URL field, enter the URL to which you want your payers redirected after they complete their payments. NOTE: PayPal checks the Return URL that you enter. If the URL is not properly formatted or cannot be validated, PayPal will not activate Auto Return.
  7. Scroll to the bottom of the page, and click the Save button.

IPN is for instant payment notification. It will give you more reliable/useful information than what you'll get from auto-return.

Documentation for IPN is here:

Online Documentation for IPN:

The general procedure is that you pass a notify_url parameter with the request, and set up a page which handles and validates IPN notifications, and PayPal will send requests to that page to notify you when payments/refunds/etc. go through. That IPN handler page would then be the correct place to update the database to mark orders as having been paid.

Margin while printing html page

If you know the target paper size, you can place your content in a DIV with that specific size and add a margin to that DIV to simulate the print margin. Unfortunately, I don't believe you have extra control over the print functionality apart from just show the print dialog box.

MVC Calling a view from a different controller

You can move you read.aspx view to Shared folder. It is standard way in such circumstances

Get the current URL with JavaScript?

You can get the current URL location with a hash tag by using:


 // Using href
 var URL = window.location.href;

 // Using path
 var URL = window.location.pathname;



Clang vs GCC - which produces faster binaries?

The fact that Clang compiles code faster may not be as important as the speed of the resulting binary. However, here is a series of benchmarks.

Set inputType for an EditText Programmatically?

According to the TextView docs, the programmatic version of android:password is setTransformationMethod(), not setInputType(). So something like:


should do the trick.

Does JavaScript guarantee object property order?

At the time of writing, most browsers did return properties in the same order as they were inserted, but it was explicitly not guaranteed behaviour so shouldn't have been relied upon.

The ECMAScript specification used to say:

The mechanics and order of enumerating the properties ... is not specified.

However in ES2015 and later non-integer keys will be returned in insertion order.

Facebook Javascript SDK Problem: "FB is not defined"

If you're using JQuery, try putting FB withing Jquery call


    FB.Event.subscribe('auth.login', function(){
        alert('logged in!');

that worked for me

How to know elastic search installed version from kibana?

navigate to the folder where you have installed your kibana if you have used yum to install kibana it will be placed in following location by default


then use the following command

bin/kibana --version

Open application after clicking on Notification

This is the way that I have approached.

public class AppFCMService extends FirebaseMessagingService {

    private final static String TAG = "FCM Message";
    String notify, requstId, Notification;
    PendingIntent pendingIntent;

    public void onMessageReceived(RemoteMessage remoteMessage) {
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Notification Message Body: " + remoteMessage.getNotification().getBody());
        //split string and getting order id from notification
        String Str = remoteMessage.getNotification().getBody();
        String[] tmp;
        tmp = Str.split(" ");
        String temp1 = tmp[0];
        String temp2 = tmp[1];
        String id = tmp[2];
        notify = temp1 + " " + temp2;
        requstId = id;

    private void showNotification(String messageBody) {
        // check whether session has been initiated or not
        if (new SessionHelper(getApplicationContext()).isLoggedIn()) {

            if (notify.equalsIgnoreCase("Travel request")) {

                Intent intent = new Intent(this, ViewTravelDetailsActivity.class);
                intent.putExtra("TravelRequestID", requstId);
                intent.putExtra("BackPress", "Notify");
                pendingIntent = PendingIntent.getActivity(this, 0, intent,

            } else if (notify.equalsIgnoreCase("Timesheet replied")) {

                Intent intent = new Intent(this, ViewReplyActivity.class);
                intent.putExtra("timesheetActivityID", requstId);
                intent.putExtra("BackPress", "Notify");
                intent.putExtra("RealmData", "DeleteRealm");
                intent.putExtra("isToday", "true");
                pendingIntent = PendingIntent.getActivity(this, 0, intent,
            } else {

                Intent intent = new Intent(this, Dashboard.class);
                intent.putExtra("timesheetActivityID", requstId);
                pendingIntent = PendingIntent.getActivity(this, 0, intent,
        } else {

            Intent intent = new Intent(this, LoginActivity.class);
            intent.putExtra("timesheetActivityID", requstId);
            pendingIntent = PendingIntent.getActivity(this, 0, intent,

        Bitmap notifyImage = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
        Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

Simple CSS: Text won't center in a button

You can bootstrap. Now a days, almost all websites are developed using bootstrap. You can simply add bootstrap link in head of html file. Now simply add class="btn btn-primary" and your button will look like a normal button. Even you can use btn class on a tag as well, it will look like button on UI.

How can I pass a parameter to a Java Thread?

No you can't pass parameters to the run() method. The signature tells you that (it has no parameters). Probably the easiest way to do this would be to use a purpose-built object that takes a parameter in the constructor and stores it in a final variable:

public class WorkingTask implements Runnable
    private final Object toWorkWith;

    public WorkingTask(Object workOnMe)
        toWorkWith = workOnMe;

    public void run()
        //do work

Thread t = new Thread(new WorkingTask(theData));

Once you do that - you have to be careful of the data integrity of the object you pass into the 'WorkingTask'. The data will now exist in two different threads so you have to make sure it is Thread Safe.

gcloud command not found - while installing Google Cloud SDK

$ sudo su
$ /opt/google-appengine-sdk/bin/gcloud components update
$ su <yourusername>

current/duration time of html5 video?

// Get the <video> element with id="myVideo"
var vid = document.getElementById("myVideo");

// Assign an ontimeupdate event to the <video> element, and execute a function if the current playback position has changed
vid.ontimeupdate = function() {myFunction()};

function myFunction() {
// Display the current position of the video in a <p> element with id="demo"
    document.getElementById("demo").innerHTML = vid.currentTime;

Move UIView up when the keyboard appears in iOS

Just in case someone is looking for solution in Swift, throw this in your code:

override func viewWillAppear(_ animated: Bool) {

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: .UIKeyboardWillHide, object: nil)

override func viewWillDisappear(_ animated: Bool) {

    NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
    NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)

@objc func keyboardWillShow(notification: Notification) {
    if let userInfo = notification.userInfo {
        if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            UIView.animate(withDuration: 0.3) {
                var alteredFrame = self.view.frame
                alteredFrame.origin.y = -keyboardSize.height
                self.view.frame = alteredFrame

@objc func keyboardWillHide(notification: Notification) {
    UIView.animate(withDuration: 0.3) {
        var alteredFrame = self.view.frame
        alteredFrame.origin.y = 0.0
        self.view.frame = alteredFrame

<DIV> inside link (<a href="">) tag

As of HTML5 it is OK to wrap <a> elements around a <div> (or any other block elements):

The a element may be wrapped around entire paragraphs, lists, tables, and so forth, even entire sections, so long as there is no interactive content within (e.g. buttons or other links).

Just have to make sure you don't put an <a> within your <a> ( or a <button>).

null terminating a string

From the comp.lang.c FAQ:

In essence: NULL (the preprocessor macro for the null pointer) is not the same as NUL (the null character).

How to center a <p> element inside a <div> container?

You only need to add text-align: center to your <div>

In your case also remove both styles that you added to your <p>.

Check out the demo here:

Good Luck

How to copy a dictionary and only edit the copy

As others have explained, the built-in dict does not do what you want. But in Python2 (and probably 3 too) you can easily create a ValueDict class that copies with = so you can be sure that the original will not change.

class ValueDict(dict):

    def __ilshift__(self, args):
        result = ValueDict(self)
        if isinstance(args, dict):
            dict.update(result, args)
            dict.__setitem__(result, *args)
        return result # Pythonic LVALUE modification

    def __irshift__(self, args):
        result = ValueDict(self)
        dict.__delitem__(result, args)
        return result # Pythonic LVALUE modification

    def __setitem__(self, k, v):
        raise AttributeError, \
            "Use \"value_dict<<='%s', ...\" instead of \"d[%s] = ...\"" % (k,k)

    def __delitem__(self, k):
        raise AttributeError, \
            "Use \"value_dict>>='%s'\" instead of \"del d[%s]" % (k,k)

    def update(self, d2):
        raise AttributeError, \
            "Use \"value_dict<<=dict2\" instead of \"value_dict.update(dict2)\""

# test
d = ValueDict()

d <<='apples', 5
d <<='pears', 8
print "d =", d

e = d
e <<='bananas', 1
print "e =", e
print "d =", d

d >>='pears'
print "d =", d
d <<={'blueberries': 2, 'watermelons': 315}
print "d =", d
print "e =", e
print "e['bananas'] =", e['bananas']

# result
d = {'apples': 5, 'pears': 8}
e = {'apples': 5, 'pears': 8, 'bananas': 1}
d = {'apples': 5, 'pears': 8}
d = {'apples': 5}
d = {'watermelons': 315, 'blueberries': 2, 'apples': 5}
e = {'apples': 5, 'pears': 8, 'bananas': 1}
e['bananas'] = 1

# e[0]=3
# would give:
# AttributeError: Use "value_dict<<='0', ..." instead of "d[0] = ..."

Please refer to the lvalue modification pattern discussed here: Python 2.7 - clean syntax for lvalue modification. The key observation is that str and int behave as values in Python (even though they're actually immutable objects under the hood). While you're observing that, please also observe that nothing is magically special about str or int. dict can be used in much the same ways, and I can think of many cases where ValueDict makes sense.

Query to list all stored procedures

select *  
  from dbo.sysobjects
 where xtype = 'P'
   and status > 0

SQL Query to add a new column after an existing column in SQL Server 2005

First add the new column to the old table through SSMStudio. Go to the database >> table >> columns. Right click on columns and choose new column. Follow the wizard. Then create the new table with the columns ordered as desired as follows:

select * into my_new_table from (
select old_col1, my_new_col, old_col2, old_col3
from my_old_table 
) as A

Then rename the tables as desired through SSMStudio. Go to the database >> table >> choose rename.

Django - taking values from POST request

For django forms you can do this;

form = UserLoginForm(data=request.POST) #getting the whole data from the user.
user = #saving the details obtained from the user.
username = user.cleaned_data.get("username") #where "username" in parenthesis is the name of the Charfield (the variale name i.e, username = forms.Charfield(max_length=64))

Resize Cross Domain Iframe Height

It is only possible to do this cross domain if you have access to implement JS on both domains. If you have that, then here is a little library that solves all the problems with sizing iFrames to their contained content.

It deals with the cross domain issue by using the post-message API, and also detects changes to the content of the iFrame in a few different ways.

Works in all modern browsers and IE8 upwards.

How to pass data from Javascript to PHP and vice versa?

You can pass data from PHP to javascript but the only way to get data from javascript to PHP is via AJAX.

The reason for that is you can build a valid javascript through PHP but to get data to PHP you will need to get PHP running again, and since PHP only runs to process the output, you will need a page reload or an asynchronous query.

arranging div one below the other

The default behaviour of divs is to take the full width available in their parent container.
This is the same as if you'd give the inner divs a width of 100%.

By floating the divs, they ignore their default and size their width to fit the content. Everything behind it (in the HTML), is placed under the div (on the rendered page).
This is the reason that they align theirselves next to each other.

The float CSS property specifies that an element should be taken from the normal flow and placed along the left or right side of its container, where text and inline elements will wrap around it. A floating element is one where the computed value of float is not none.


Get rid of the float, and the divs will be aligned under each other.
If this does not happen, you'll have some other css on divs or children of wrapper defining a floating behaviour or an inline display.

If you want to keep the float, for whatever reason, you can use clear on the 2nd div to reset the floating properties of elements before that element.
clear has 5 valid values: none | left | right | both | inherit. Clearing no floats (used to override inherited properties), left or right floats or both floats. Inherit means it'll inherit the behaviour of the parent element

Also, because of the default behaviour, you don't need to set the width and height on auto.
You only need this is you want to set a hardcoded height/width. E.g. 80% / 800px / 500em / ...

<div id="wrapper">
    <div id="inner1"></div>
    <div id="inner2"></div>

CSS is

    height:auto; // this is not needed, as parent container, this div will size automaticly
    width:auto; // this is not needed, as parent container, this div will size automaticly

You can get rid of the inner divs in the css, unless you want to style them.
If you want to style them identicly, you can use concatenation
#inner1, #inner2 {
    border: 1px solid black;

How to re-sync the Mysql DB if Master and slave have different database incase of Mysql replication?

Unless you are writing directly to the slave (Server2) the only problem should be that Server2 is missing any updates that have happened since it was disconnected. Simply restarting the slave with "START SLAVE;" should get everything back up to speed.

Python threading.timer - repeat function every 'n' seconds

In addition to the above great answers using Threads, in case you have to use your main thread or prefer an async approach - I wrapped a short class around aio_timers Timer class (to enable repeating)

import asyncio
from aio_timers import Timer

class RepeatingAsyncTimer():
    def __init__(self, interval, cb, *args, **kwargs):
        self.interval = interval
        self.cb = cb
        self.args = args
        self.kwargs = kwargs
        self.aio_timer = None
    def start_timer(self):
        self.aio_timer = Timer(delay=self.interval, 
    def cb_wrapper(self, *args, **kwargs):
        self.cb(*args, **kwargs)

from time import time
def cb(timer_name):
    print(timer_name, time())

print(f'clock starts at: {time()}')
timer_1 = RepeatingAsyncTimer(interval=5, cb=cb, timer_name='timer_1')
timer_2 = RepeatingAsyncTimer(interval=10, cb=cb, timer_name='timer_2')

clock starts at: 1602438840.9690785

timer_1 1602438845.980087

timer_2 1602438850.9806316

timer_1 1602438850.9808934

timer_1 1602438855.9863033

timer_2 1602438860.9868324

timer_1 1602438860.9876585

Get the last inserted row ID (with SQL statement)

You can use:


to access the latest identity for a perticular table.

e.g. Considering following code:

INSERT INTO dbo.MyTable(columns....) VALUES(..........)

INSERT INTO dbo.YourTable(columns....) VALUES(..........)



This would yield to correct value for corresponding tables.

It returns the last IDENTITY value produced in a table, regardless of the connection that created the value, and regardless of the scope of the statement that produced the value.

IDENT_CURRENT is not limited by scope and session; it is limited to a specified table. IDENT_CURRENT returns the identity value generated for a specific table in any session and any scope.

How to get a dependency tree for an artifact?

1) Use maven dependency plugin

Create a simple project with pom.xml only. Add your dependency and run:

mvn dependency:tree

Unfortunately dependency mojo must use pom.xml or you get following error:

Cannot execute mojo: tree. It requires a project with an existing pom.xml, but the build is not using one.

2) Find pom.xml of your artifact in maven central repository

Dependencies are described In pom.xml of your artifact. Find it using maven infrastructure.

Go to and enter your groupId and artifactId.

Or you can go to and navigate first using plugins groupId, later using artifactId and finally using its version.

For example see org.springframework:spring-core

3) Use maven dependency plugin against your artifact

Part of dependency artifact is a pom.xml. That specifies it's dependency. And you can execute mvn dependency:tree on this pom.

Restart android machine

Have you tried simply 'reboot' with adb?

  adb reboot

Also you can run complete shell scripts (e.g. to reboot your emulator) via adb:

 adb shell <command>

The official docs can be found here.

Find object in list that has attribute equal to some value (that meets any condition)

Since it has not been mentioned just for completion. The good ol' filter to filter your to be filtered elements.

Functional programming ftw.

####### Set Up #######
class X:

    def __init__(self, val):
        self.val = val

elem = 5

my_unfiltered_list = [X(1), X(2), X(3), X(4), X(5), X(5), X(6)]

####### Set Up #######

### Filter one liner ### filter(lambda x: condition(x), some_list)
my_filter_iter = filter(lambda x: x.val == elem, my_unfiltered_list)
### Returns a flippin' iterator at least in Python 3.5 and that's what I'm on


### [1, 2, 3, 4, 5, 5, 6] Will Return: ###
# 5
# 5
# Traceback (most recent call last):
#   File "C:\Users\mousavin\workspace\Scripts\", line 22, in <module>
#     print(next(my_filter_iter).value)
# StopIteration

# You can do that None stuff or whatever at this point, if you don't like exceptions.

I know that generally in python list comprehensions are preferred or at least that is what I read, but I don't see the issue to be honest. Of course Python is not an FP language, but Map / Reduce / Filter are perfectly readable and are the most standard of standard use cases in functional programming.

So there you go. Know thy functional programming.

filter condition list

It won't get any easier than this:

next(filter(lambda x: x.val == value,  my_unfiltered_list)) # Optionally: next(..., None) or some other default value to prevent Exceptions

How do I insert multiple checkbox values into a table?

I think you should $_POST[][], i tried it and it work :)), tks

How to uninstall a Windows Service when there is no executable for it left on the system?

My favourite way of doing this is to use Sysinternals Autoruns application. Just select the service and press delete.

Java, How to implement a Shift Cipher (Caesar Cipher)

Below code handles upper and lower cases as well and leaves other character as it is.

import java.util.Scanner;

public class CaesarCipher
    public static void main(String[] args)
    Scanner in = new Scanner(;
    int length = Integer.parseInt(in.nextLine());
    String str = in.nextLine();
    int k = Integer.parseInt(in.nextLine());

    k = k % 26;

    System.out.println(encrypt(str, length, k));


    private static String encrypt(String str, int length, int shift)
    StringBuilder strBuilder = new StringBuilder();
    char c;
    for (int i = 0; i < length; i++)
        c = str.charAt(i);
        // if c is letter ONLY then shift them, else directly add it
        if (Character.isLetter(c))
        c = (char) (str.charAt(i) + shift);
        // System.out.println(c);

        // checking case or range check is important, just if (c > 'z'
        // || c > 'Z')
        // will not work
        if ((Character.isLowerCase(str.charAt(i)) && c > 'z')
            || (Character.isUpperCase(str.charAt(i)) && c > 'Z'))

            c = (char) (str.charAt(i) - (26 - shift));
    return strBuilder.toString();

How to use GROUP_CONCAT in a CONCAT in MySQL

    FROM test GROUP BY id

you must use cast or convert, otherwise will be return BLOB

result is

id         Column
1          A:4,A:5,B:8
2          C:9

you have to handle result once again by program such as python or java

How to create large PDF files (10MB, 50MB, 100MB, 200MB, 500MB, 1GB, etc.) for testing purposes?

One possibility is, if you are familiar with PDF format:

  1. Create some simply PDF with one page (Page should be contained within one object)
  2. Copy object multiply times
  3. Add references to the copied objects to the page catalog
  4. Fix xref table

You get an valid document of any size, entire file will be processed by a reader.

How to convert file to base64 in JavaScript?

const fileInput = document.querySelector('input');

fileInput.addEventListener('change', (e) => {

// get a reference to the file
const file =[0];

// encode the file using the FileReader API
const reader = new FileReader();
reader.onloadend = () => {

    // use a regex to remove data url part
    const base64String = reader.result
        .replace('data:', '')
        .replace(/^.+,/, '');

    // log to console
    // logs wL2dvYWwgbW9yZ...

Laravel Eloquent compare date from datetime field

Laravel 4+ offers you these methods: whereDay(), whereMonth(), whereYear() (#3946) and whereDate() (#6879).

They do the SQL DATE() work for you, and manage the differences of SQLite.

Your result can be achieved as so:

->whereDate('date', '<=', '2014-07-10')

For more examples, see first message of #3946 and this Laravel Daily article.

Update: Though the above method is convenient, as noted by Arth it is inefficient on large datasets, because the DATE() SQL function has to be applied on each record, thus discarding the possible index.

Here are some ways to make the comparison (but please read notes below):

->where('date', '<=', '2014-07-10 23:59:59')

->where('date', '<', '2014-07-11')

// '2014-07-11'
$dayAfter = (new DateTime('2014-07-10'))->modify('+1 day')->format('Y-m-d');

->where('date', '<', $dayAfter)


  • 23:59:59 is okay (for now) because of the 1-second precision, but have a look at this article: 23:59:59 is not the end of the day. No, really!
  • Keep in mind the "zero date" case ("0000-00-00 00:00:00"). Though, these "zero dates" should be avoided, they are source of so many problems. Better make the field nullable if needed.

Git push rejected after feature branch rebase

What is wrong with a git merge master on the feature branch? This will preserve the work you had, while keeping it separate from the mainline branch.

       \         \

Edit: Ah sorry did not read your problem statement. You will need force as you performed a rebase. All commands that modify the history will need the --force argument. This is a failsafe to prevent you from losing work (the old D and E would be lost).

So you performed a git rebase which made the tree look like (although partially hidden as D and E are no longer in a named branch):

       \         \
        D--E      D'--E'

So, when trying to push your new feature branch (with D' and E' in it), you would lose D and E.

Fuzzy matching using T-SQL

I've found that the stuff SQL Server gives you to do fuzzy matching is pretty clunky. I've had really good luck with my own CLR functions using the Levenshtein distance algorithm and some weighting. Using that algorithm, I've then made a UDF called GetSimilarityScore that takes two strings and returns a score between 0.0 and 1.0. The closer to 1.0 the match is, the better. Then, query with a threshold of >=0.8 or so to get the most likely matches. Something like this:

if object_id('tempdb..#similar') is not null drop table #similar
select, (
    select top 1
   from MyTable x
   where <>
   order by dbo.GetSimilarityScore(a.MyField, x.MyField) desc
) as MostSimilarId
into #similar
from MyTable a

select *, dbo.GetSimilarityScore(a.MyField, c.MyField)
from MyTable a
join #similar b on =
join MyTable c on b.MostSimilarId =

Just don't do it with really large tables. It's a slow process.

Here's the CLR UDFs:

''' <summary>
''' Compute the distance between two strings.
''' </summary>
''' <param name="s1">The first of the two strings.</param>
''' <param name="s2">The second of the two strings.</param>
''' <returns>The Levenshtein cost.</returns>
<Microsoft.SqlServer.Server.SqlFunction()> _
Public Shared Function ComputeLevenstheinDistance(ByVal string1 As SqlString, ByVal string2 As SqlString) As SqlInt32
    If string1.IsNull OrElse string2.IsNull Then Return SqlInt32.Null
    Dim s1 As String = string1.Value
    Dim s2 As String = string2.Value

    Dim n As Integer = s1.Length
    Dim m As Integer = s2.Length
    Dim d As Integer(,) = New Integer(n, m) {}

    ' Step 1
    If n = 0 Then Return m
    If m = 0 Then Return n

    ' Step 2
    For i As Integer = 0 To n
        d(i, 0) = i

    For j As Integer = 0 To m
        d(0, j) = j

    ' Step 3
    For i As Integer = 1 To n
        'Step 4
        For j As Integer = 1 To m
            ' Step 5
            Dim cost As Integer = If((s2(j - 1) = s1(i - 1)), 0, 1)

            ' Step 6
            d(i, j) = Math.Min(Math.Min(d(i - 1, j) + 1, d(i, j - 1) + 1), d(i - 1, j - 1) + cost)
    ' Step 7
    Return d(n, m)
End Function

''' <summary>
''' Returns a score between 0.0-1.0 indicating how closely two strings match.  1.0 is a 100%
''' T-SQL equality match, and the score goes down from there towards 0.0 for less similar strings.
''' </summary>
<Microsoft.SqlServer.Server.SqlFunction()> _
Public Shared Function GetSimilarityScore(string1 As SqlString, string2 As SqlString) As SqlDouble
    If string1.IsNull OrElse string2.IsNull Then Return SqlInt32.Null

    Dim s1 As String = string1.Value.ToUpper().TrimEnd(" "c)
    Dim s2 As String = string2.Value.ToUpper().TrimEnd(" "c)
    If s1 = s2 Then Return 1.0F ' At this point, T-SQL would consider them the same, so I will too

    Dim flatLevScore As Double = InternalGetSimilarityScore(s1, s2)

    Dim letterS1 As String = GetLetterSimilarityString(s1)
    Dim letterS2 As String = GetLetterSimilarityString(s2)
    Dim letterScore As Double = InternalGetSimilarityScore(letterS1, letterS2)

    'Dim wordS1 As String = GetWordSimilarityString(s1)
    'Dim wordS2 As String = GetWordSimilarityString(s2)
    'Dim wordScore As Double = InternalGetSimilarityScore(wordS1, wordS2)

    If flatLevScore = 1.0F AndAlso letterScore = 1.0F Then Return 1.0F
    If flatLevScore = 0.0F AndAlso letterScore = 0.0F Then Return 0.0F

    ' Return weighted result
    Return (flatLevScore * 0.2F) + (letterScore * 0.8F)
End Function

Private Shared Function InternalGetSimilarityScore(s1 As String, s2 As String) As Double
    Dim dist As SqlInt32 = ComputeLevenstheinDistance(s1, s2)
    Dim maxLen As Integer = If(s1.Length > s2.Length, s1.Length, s2.Length)
    If maxLen = 0 Then Return 1.0F
    Return 1.0F - Convert.ToDouble(dist.Value) / Convert.ToDouble(maxLen)
End Function

''' <summary>
''' Sorts all the alpha numeric characters in the string in alphabetical order
''' and removes everything else.
''' </summary>
Private Shared Function GetLetterSimilarityString(s1 As String) As String
    Dim allChars = If(s1, "").ToUpper().ToCharArray()
    Dim result As New StringBuilder()
    For Each ch As Char In allChars
        If Char.IsLetterOrDigit(ch) Then
        End If
    Return result.ToString()
End Function

''' <summary>
''' Removes all non-alpha numeric characters and then sorts
''' the words in alphabetical order.
''' </summary>
Private Shared Function GetWordSimilarityString(s1 As String) As String
    Dim words As New List(Of String)()
    Dim curWord As StringBuilder = Nothing
    For Each ch As Char In If(s1, "").ToUpper()
        If Char.IsLetterOrDigit(ch) Then
            If curWord Is Nothing Then
                curWord = New StringBuilder()
            End If
            If curWord IsNot Nothing Then
                curWord = Nothing
            End If
        End If
    If curWord IsNot Nothing Then
    End If

    Return String.Join(" ", words.ToArray())
End Function

How to enable CORS in AngularJs

This issue occurs because of web application security model policy that is Same Origin Policy Under the policy, a web browser permits scripts contained in a first web page to access data in a second web page, but only if both web pages have the same origin. That means requester must match the exact host, protocol, and port of requesting site.

We have multiple options to over come this CORS header issue.

  1. Using Proxy - In this solution we will run a proxy such that when request goes through the proxy it will appear like it is some same origin. If you are using the nodeJS you can use cors-anywhere to do the proxy stuff.


    var host = process.env.HOST || '';
    var port = process.env.PORT || 8080;
    var cors_proxy = require('cors-anywhere');
        originWhitelist: [], // Allow all origins
        requireHeader: ['origin', 'x-requested-with'],
        removeHeaders: ['cookie', 'cookie2']
    }).listen(port, host, function() {
        console.log('Running CORS Anywhere on ' + host + ':' + port);
  2. JSONP - JSONP is a method for sending JSON data without worrying about cross-domain issues.It does not use the XMLHttpRequest object.It uses the <script> tag instead.

  3. Server Side - On server side we need to enable cross-origin requests. First we will get the Preflighted requests (OPTIONS) and we need to allow the request that is status code 200 (ok).

    Preflighted requests first send an HTTP OPTIONS request header to the resource on the other domain, in order to determine whether the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data. In particular, a request is preflighted if it uses methods other than GET or POST. Also, if POST is used to send request data with a Content-Type other than application/x-www-form-urlencoded, multipart/form-data, or text/plain, e.g. if the POST request sends an XML payload to the server using application/xml or text/xml, then the request is preflighted. It sets custom headers in the request (e.g. the request uses a header such as X-PINGOTHER)

    If you are using the spring just adding the bellow code will resolves the issue. Here I have disabled the csrf token that doesn't matter enable/disable according to your requirement.

    public class SupplierServicesApplication {
        public static void main(String[] args) {
  , args);
        public WebMvcConfigurer corsConfigurer() {
            return new WebMvcConfigurerAdapter() {
                public void addCorsMappings(CorsRegistry registry) {

    If you are using the spring security use below code along with above code.

    public class SupplierSecurityConfig extends WebSecurityConfigurerAdapter {
        protected void configure(HttpSecurity http) throws Exception {
            http.csrf().disable().authorizeRequests().antMatchers(HttpMethod.OPTIONS, "/**").permitAll().antMatchers("/**").authenticated().and()

Run javascript function when user finishes typing instead of on key up?

Late answer but I'm adding it because it's 2019 and this is entirely achievable using pretty ES6, no third party libraries, and I find most of the highly rated answers are bulky and weighed down with too many variables.

Elegant solution taken from this excellent blog post.

function debounce(callback, wait) {
  let timeout;
  return (...args) => {
      timeout = setTimeout(function () { callback.apply(this, args); }, wait);

window.addEventListener('keyup', debounce( () => {
    // code you would like to run 1000ms after the keyup event has stopped firing
    // further keyup events reset the timer, as expected
}, 1000))

How to set header and options in axios?

@user2950593 Your axios request is correct. You need to allow your custom headers on server side. If you have your api in php then this code will work for you.

header("Access-Control-Allow-Origin: *");   
header("Access-Control-Allow-Methods: GET, POST, OPTIONS, HEAD");
header("Access-Control-Allow-Headers: Content-Type, header1");

Once you will allow your custom headers on server side, your axios requests will start working fine.

Android checkbox style

Maybe this will satisfy you -


    android:text="Custom CheckBox"


<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
    <item android:state_checked="true" android:drawable="@drawable/star_down" />
    <item android:state_checked="false" android:drawable="@drawable/star" />

For, the reference just refer here

How do you monitor network traffic on the iPhone?

Run it through a proxy and monitor the traffic using Wireshark.

Add tooltip to font awesome icon

The issue of adding tooltips to any HTML-Output (not only FontAwesome) is an entire book on its own. ;-)

The default way would be to use the title-attribute:

  <div id="welcomeText" title="So nice to see you!">
    <p>Welcome Harriet</p>


<i class="fa fa-cog" title="Do you like my fa-coq icon?"></i>

But since most people (including me) do not like the standard-tooltips, there are MANY tools out there which will "beautify" them and offer all sort of enhancements. My personal favourites are jBox and qtip2.

How to display raw html code in PRE or something like it but without escaping it

If you have jQuery enabled you can use an escapeXml function and not have to worry about escaping arrows or special characters.

    <!-- all your code --> 

How to write a cursor inside a stored procedure in SQL Server 2008

You can create a trigger which updates NoofUses column in Coupon table whenever couponid is used in CouponUse table

query :

CREATE TRIGGER [dbo].[couponcount] ON [dbo].[couponuse]
if EXISTS (SELECT 1 FROM Inserted)
UPDATE dbo.Coupon
SET NoofUses = (SELECT COUNT(*) FROM dbo.CouponUse WHERE Couponid = dbo.Coupon.ID)

MySQL Creating tables with Foreign Keys giving errno: 150

Make sure that the properties of the two fields you are trying to link with a constraint are exactly the same.

Often, the 'unsigned' property on an ID column will catch you out.

ALTER TABLE `dbname`.`tablename` CHANGE `fieldname` `fieldname` int(10) UNSIGNED NULL;

How to parse month full form string using DateFormat in Java?

Just to top this up to the new Java 8 API:

DateTimeFormatter formatter = new DateTimeFormatterBuilder().appendPattern("MMMM dd, yyyy").toFormatter();
TemporalAccessor ta = formatter.parse("June 27, 2007");
Instant instant = LocalDate.from(ta).atStartOfDay().atZone(ZoneId.systemDefault()).toInstant();
Date d = Date.from(instant);
assertThat(d.getYear(), is(107));
assertThat(d.getMonth(), is(5));

A bit more verbose but you also see that the methods of Date used are deprecated ;-) Time to move on.

jQuery get the image src

When dealing with the HTML DOM (ie. this), the array selector [0] must be used to retrieve the jQuery element from the Javascript array.


In angular $http service, How can I catch the "status" of error?

The $http legacy promise methods success and error have been deprecated. Use the standard then method instead. Have a look at the docs$http

Now the right way to use is:

// Simple GET request example:
  method: 'GET',
  url: '/someUrl'
}).then(function successCallback(response) {
    // this callback will be called asynchronously
    // when the response is available
  }, function errorCallback(response) {
    // called asynchronously if an error occurs
    // or server returns response with an error status.

The response object has these properties:

  • data – {string|Object} – The response body transformed with the transform functions.
  • status – {number} – HTTP status code of the response.
  • headers – {function([headerName])} – Header getter function.
  • config – {Object} – The configuration object that was used to generate the request.
  • statusText – {string} – HTTP status text of the response.

A response status code between 200 and 299 is considered a success status and will result in the success callback being called.

support FragmentPagerAdapter holds reference to old fragments

Global working tested solution.

getSupportFragmentManager() keeps the null reference some times and View pager does not create new since it find reference to same fragment. So to over come this use getChildFragmentManager() solves problem in simple way.

Don't do this:

new PagerAdapter(getSupportFragmentManager(), fragments);

Do this:

new PagerAdapter(getChildFragmentManager() , fragments);

How to remove duplicates from Python list and keep order?

A list can be sorted and deduplicated using built-in functions:

myList = sorted(set(myList))
  • set is a built-in function for Python >= 2.3
  • sorted is a built-in function for Python >= 2.4

How to run an android app in background?

You can probably start a Service here if you want your Application to run in Background. This is what Service in Android are used for - running in background and doing longtime operations.


You can use START_STICKY to make your Service running continuously.

public int onStartCommand(Intent intent, int flags, int startId) {
    // We want this service to continue running until it is explicitly
    // stopped, so return sticky.
    return START_STICKY;

Selenium wait until document is ready

In Java it will like below :-

  private static boolean isloadComplete(WebDriver driver)
        return ((JavascriptExecutor) driver).executeScript("return document.readyState").equals("loaded")
                || ((JavascriptExecutor) driver).executeScript("return document.readyState").equals("complete");

Appending values to dictionary in Python

You can use the update() method as well

d = {"a": 2}
d.update{"b": 4}
print(d) # {"a": 2, "b": 4}

How to list physical disks?

If you only need to look at the existing disks, this one will suffice:

powershell "get-physicaldisk"

Remove duplicated rows

Remove duplicate rows of a dataframe

mydata <- mtcars

# Remove duplicate rows of the dataframe

In this dataset, there is not a single duplicate row so it returned same number of rows as in mydata.

Remove Duplicate Rows based on a one variable

mydata <- mtcars

# Remove duplicate rows of the dataframe using carb variable
distinct(mydata,carb, .keep_all= TRUE)

The .keep_all function is used to retain all other variables in the output data frame.

Remove Duplicate Rows based on multiple variables

mydata <- mtcars

# Remove duplicate rows of the dataframe using cyl and vs variables
distinct(mydata, cyl,vs, .keep_all= TRUE)

The .keep_all function is used to retain all other variables in the output data frame.

(from: ) has key method?

JObject.ContainsKey(string propertyName) has been made as public method in 11.0.1 release

Documentation -

Google Maps API warning: NoApiKeys

A key currently still is not required ("required" in the meaning "it will not work without"), but I think there is a good reason for the warning.

But in the documentation you may read now : "All JavaScript API applications require authentication."

I'm sure that it's planned for the future , that Javascript API Applications will not work without a key(as it has been in V2).

You better use a key when you want to be sure that your application will still work in 1 or 2 years.

AVD Manager - No system image installed for this target

you should android sdk manager install 4.2 api 17 -> ARM EABI v7a System Image

if not installed ARM EABI v7a System Image, you should install all.

How to copy directories in OS X 10.7.3?


cp -R "/src/project 1/App" "/src/project 2"


Using quotes will cater for spaces in the directory names

cp -R "/src/project 1/App" "/src/project 2"

If the App directory is specified in the destination directory:

cp -R "/src/project 1/App" "/src/project 2/App"

and "/src/project 2/App" already exists the result will be "/src/project 2/App/App"

Best not to specify the directory copied in the destination so that the command can be repeated over and over with the expected result.

Inside a bash script:

cp -R "${1}/App" "${2}"

A select query selecting a select statement

I was over-complicating myself. After taking a long break and coming back, the desired output could be accomplished by this simple query:

SELECT Sandwiches.[Sandwich Type], Sandwich.Bread, Count(Sandwiches.[SandwichID]) AS [Total Sandwiches]
FROM Sandwiches
GROUP BY Sandwiches.[Sandwiches Type], Sandwiches.Bread;

Thanks for answering, it helped my train of thought.

What is the difference between .py and .pyc files?

"A program doesn't run any faster when it is read from a ".pyc" or ".pyo" file than when it is read from a ".py" file; the only thing that's faster about ".pyc" or ".pyo" files is the speed with which they are loaded. "

Java String.split() Regex

You could also do something like:

String str = "a + b - c * d / e < f > g >= h <= i == j";
String[] arr = str.split("(?<=\\G(\\w+(?!\\w+)|==|<=|>=|\\+|/|\\*|-|(<|>)(?!=)))\\s*");

It handles white spaces and words of variable length and produces the array:

[a, +, b, -, c, *, d, /, e, <, f, >, g, >=, h, <=, i, ==, j]

sql select with column name like

Blorgbeard had a great answer for SQL server. If you have a MySQL server like mine then the following will allow you to select the information from columns where the name is like some key phrase. You just have to substitute the table name, database name, and keyword.

SET @columnnames = (SELECT concat("`",GROUP_CONCAT(`COLUMN_NAME` SEPARATOR "`, `"),"`") 
WHERE `TABLE_SCHEMA`='your_database' 
    AND `TABLE_NAME`='your_table'
    AND COLUMN_NAME LIKE "%keyword%");

SET @burrito = CONCAT("SELECT ",@columnnames," FROM your_table");

PREPARE result FROM @burrito;
EXECUTE result;

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

For me the line innodb_additional_mem_pool_size in my.cnf was causing it

Nodejs cannot find installed module on Windows

Add an environment variable called NODE_PATH and set it to %USERPROFILE%\Application Data\npm\node_modules (Windows XP), %AppData%\npm\node_modules (Windows 7/8/10), or wherever npm ends up installing the modules on your Windows flavor. To be done with it once and for all, add this as a System variable in the Advanced tab of the System Properties dialog (run control.exe sysdm.cpl,System,3).

Quick solution in Windows 7+ is to just run:

rem for future
setx NODE_PATH %AppData%\npm\node_modules
rem for current session
set NODE_PATH=%AppData%\npm\node_modules

It's worth to mention that NODE_PATH is only used when importing modules in Node apps. When you want to use globally installed modules' binaries in your CLI you need to add it also to your PATH, but without node_modules part (for example %AppData%\npm in Windows 7/8/10).

Old story

I'm pretty much new to node.js myself so I can be not entirely right but from my experience it's works this way:

  1. -g is not a way to install global libraries, it's only a way to place them on system path so you can call them from command line without writing the full path to them. It is useful, for example, then node app is converting local files, like less — if you install it globally you can use it in any directory.
  2. node.js itself didn't look at the npm global dir, it is using another algorithm to find required files: (basically its scanning every folder in the path, starting from the current for node_modules folder and checks it).

See similar question for more details: How do I install a module globally using npm?

How can I debug what is causing a connection refused or a connection time out?

The problem

The problem is in the network layer. Here are the status codes explained:

  • Connection refused: The peer is not listening on the respective network port you're trying to connect to. This usually means that either a firewall is actively denying the connection or the respective service is not started on the other site or is overloaded.

  • Connection timed out: During the attempt to establish the TCP connection, no response came from the other side within a given time limit. In the context of urllib this may also mean that the HTTP response did not arrive in time. This is sometimes also caused by firewalls, sometimes by network congestion or heavy load on the remote (or even local) site.

In context

That said, it is probably not a problem in your script, but on the remote site. If it's occuring occasionally, it indicates that the other site has load problems or the network path to the other site is unreliable.

Also, as it is a problem with the network, you cannot tell what happened on the other side. It is possible that the packets travel fine in the one direction but get dropped (or misrouted) in the other.

It is also not a (direct) DNS problem, that would cause another error (Name or service not known or something similar). It could however be the case that the DNS is configured to return different IP addresses on each request, which would connect you (DNS caching left aside) to different addresses hosts on each connection attempt. It could in turn be the case that some of these hosts are misconfigured or overloaded and thus cause the aforementioned problems.

Debugging this

As suggested in the another answer, using a packet analyzer can help to debug the issue. You won't see much however except the packets reflecting exactly what the error message says.

To rule out network congestion as a problem you could use a tool like mtr or traceroute or even ping to see if packets get lost to the remote site. Note that, if you see loss in mtr (and any traceroute tool for that matter), you must always consider the first host where loss occurs (in the route from yours to remote) as the one dropping packets, due to the way ICMP works. If the packets get lost only at the last hop over a long time (say, 100 packets), that host definetly has an issue. If you see that this behaviour is persistent (over several days), you might want to contact the administrator.

Loss in a middle of the route usually corresponds to network congestion (possibly due to maintenance), and there's nothing you could do about it (except whining at the ISP about missing redundance).

If network congestion is not a problem (i.e. not more than, say, 5% of the packets get lost), you should contact the remote server administrator to figure out what's wrong. He may be able to see relevant infos in system logs. Running a packet analyzer on the remote site might also be more revealing than on the local site. Checking whether the port is open using netstat -tlp is definetly recommended then.

How to set ObjectId as a data type in mongoose

The solution provided by @dex worked for me. But I want to add something else that also worked for me: Use

let UserSchema = new Schema({
   username: {
     type: String
   events: [{
     type: ObjectId,
     ref: 'Event' // Reference to some EventSchema

if what you want to create is an Array reference. But if what you want is an Object reference, which is what I think you might be looking for anyway, remove the brackets from the value prop, like this:

let UserSchema = new Schema({
   username: {
     type: String
   events: {
     type: ObjectId,
     ref: 'Event' // Reference to some EventSchema

Look at the 2 snippets well. In the second case, the value prop of key events does not have brackets over the object def.

Python's "in" set operator

Yes it can mean so, or it can be a simple iterator. For example: Example as iterator:

for x in a:
 print ('This set contains the value ' + x)

Similarly as a check:

if 'I' in a:
 print ('There is an "I" in here')

edited: edited to include sets rather than lists and strings

What is the difference between public, private, and protected?

The mentioned keywords are access modifiers and help us implement Encapsulation (or information hiding). They tell the compiler which other classes should have access to the field or method being defined.

private - Only the current class will have access to the field or method.

protected - Only the current class and subclasses (and sometimes also same-package classes) of this class will have access to the field or method.

public - Any class can refer to the field or call the method.

Defining an abstract class without any abstract methods

Yes you can. The abstract class used in java signifies that you can't create an object of the class. And an abstract method the subclasses have to provide an implementation for that method.

So you can easily define an abstract class without any abstract method.

As for Example :

public abstract class AbstractClass{

    public String nonAbstractMethodOne(String param1,String param2){
        String param = param1 + param2;
        return param;

    public static void nonAbstractMethodTwo(String param){
        System.out.println("Value of param is "+param);

This is fine.

How can I return pivot table output in MySQL?

My solution is in T-SQL without any pivots:

    SUM(CASE WHEN (action='EMAIL') THEN 1 ELSE 0 END) AS Email,
    SUM(CASE WHEN (action='PRINT' AND pagecount=1) THEN 1 ELSE 0 END) AS Print1Pages,
    SUM(CASE WHEN (action='PRINT' AND pagecount=2) THEN 1 ELSE 0 END) AS Print2Pages,
    SUM(CASE WHEN (action='PRINT' AND pagecount=3) THEN 1 ELSE 0 END) AS Print3Pages

Enabling CORS in Cloud Functions for Firebase

A cors error can occur if you don't catch an error in a function. My suggestion is to implement a try catch in your corsHandler

const corsHandler = (request, response, handler) => {
    cors({ origin: true })(request, response, async () => {
        try {
            await handler();
        catch (e) {
            functions.logger.error('Error: ' + e);
            response.statusCode = 500;
                'status': 'ERROR' //Optional: customize your error message here


exports.helloWorld = functions.https.onRequest((request, response) => {
    corsHandler(request, response, () => {"Hello logs!");
            "data": "Hello from Firebase!"

Thanks to stackoverflow users: Hoang Trinh, Yayo Arellano and Doug Stevenson

Android statusbar icons color

Not since Lollipop. Starting with Android 5.0, the guidelines say:

Notification icons must be entirely white.

Even if they're not, the system will only consider the alpha channel of your icon, rendering them white


The only way to have a coloured icon on Lollipop is to lower your targetSdkVersion to values <21, but I think you would do better to follow the guidelines and use white icons only.

If you still however decide you want colored icons, you could use the DrawableCompat.setTint method from the new v4 support library.

How to detect READ_COMMITTED_SNAPSHOT is enabled?

Neither on SQL2005 nor 2012 does DBCC USEROPTIONS show is_read_committed_snapshot_on:

Set Option  Value
textsize    2147483647
language    us_english
dateformat  mdy
datefirst   7
lock_timeout    -1
quoted_identifier   SET
arithabort  SET
ansi_null_dflt_on   SET
ansi_warnings   SET
ansi_padding    SET
ansi_nulls  SET
concat_null_yields_null SET
isolation level read committed

Program does not contain a static 'Main' method suitable for an entry point

Just in case anyone is having the same problem... I was getting this error, and it turned out to be my <Application.Resources> in my App.xaml file. I had a resource outside my resource dictionary tags, and that caused this error.

Specify the from user when sending email using the mail command

Here's an answer from 2018, on Debian 9 stretch.

Note the -e for echo to allow newline characters, and -r for mailx to show a name along with an outgoing email address:

$ echo -e "testing email via from command line\n\nsent on: $(date)" | mailx -r "Foghorn Leghorn <[email protected]>" -s "test cli email $(date)" -- [email protected]

Hope this helps!

How do you convert Html to plain text?

Did not write but an using:

using HtmlAgilityPack;
using System;
using System.IO;
using System.Text.RegularExpressions;

namespace foo {
  //small but important modification to class
  public static class HtmlToText {

    public static string Convert(string path) {
      HtmlDocument doc = new HtmlDocument();
      return ConvertDoc(doc);

    public static string ConvertHtml(string html) {
      HtmlDocument doc = new HtmlDocument();
      return ConvertDoc(doc);

    public static string ConvertDoc(HtmlDocument doc) {
      using (StringWriter sw = new StringWriter()) {
        ConvertTo(doc.DocumentNode, sw);
        return sw.ToString();

    internal static void ConvertContentTo(HtmlNode node, TextWriter outText, PreceedingDomTextInfo textInfo) {
      foreach (HtmlNode subnode in node.ChildNodes) {
        ConvertTo(subnode, outText, textInfo);
    public static void ConvertTo(HtmlNode node, TextWriter outText) {
      ConvertTo(node, outText, new PreceedingDomTextInfo(false));
    internal static void ConvertTo(HtmlNode node, TextWriter outText, PreceedingDomTextInfo textInfo) {
      string html;
      switch (node.NodeType) {
        case HtmlNodeType.Comment:
          // don't output comments
        case HtmlNodeType.Document:
          ConvertContentTo(node, outText, textInfo);
        case HtmlNodeType.Text:
          // script and style must not be output
          string parentName = node.ParentNode.Name;
          if ((parentName == "script") || (parentName == "style")) {
          // get text
          html = ((HtmlTextNode)node).Text;
          // is it in fact a special closing node output as text?
          if (HtmlNode.IsOverlappedClosingElement(html)) {
          // check the text is meaningful and not a bunch of whitespaces
          if (html.Length == 0) {
          if (!textInfo.WritePrecedingWhiteSpace || textInfo.LastCharWasSpace) {
            html = html.TrimStart();
            if (html.Length == 0) { break; }
            textInfo.IsFirstTextOfDocWritten.Value = textInfo.WritePrecedingWhiteSpace = true;
          outText.Write(HtmlEntity.DeEntitize(Regex.Replace(html.TrimEnd(), @"\s{2,}", " ")));
          if (textInfo.LastCharWasSpace = char.IsWhiteSpace(html[html.Length - 1])) {
            outText.Write(' ');
        case HtmlNodeType.Element:
          string endElementString = null;
          bool isInline;
          bool skip = false;
          int listIndex = 0;
          switch (node.Name) {
            case "nav":
              skip = true;
              isInline = false;
            case "body":
            case "section":
            case "article":
            case "aside":
            case "h1":
            case "h2":
            case "header":
            case "footer":
            case "address":
            case "main":
            case "div":
            case "p": // stylistic - adjust as you tend to use
              if (textInfo.IsFirstTextOfDocWritten) {
              endElementString = "\r\n";
              isInline = false;
            case "br":
              skip = true;
              textInfo.WritePrecedingWhiteSpace = false;
              isInline = true;
            case "a":
              if (node.Attributes.Contains("href")) {
                string href = node.Attributes["href"].Value.Trim();
                if (node.InnerText.IndexOf(href, StringComparison.InvariantCultureIgnoreCase) == -1) {
                  endElementString = "<" + href + ">";
              isInline = true;
            case "li":
              if (textInfo.ListIndex > 0) {
                outText.Write("\r\n{0}.\t", textInfo.ListIndex++);
              } else {
                outText.Write("\r\n*\t"); //using '*' as bullet char, with tab after, but whatever you want eg "\t->", if utf-8 0x2022
              isInline = false;
            case "ol":
              listIndex = 1;
              goto case "ul";
            case "ul": //not handling nested lists any differently at this stage - that is getting close to rendering problems
              endElementString = "\r\n";
              isInline = false;
            case "img": //inline-block in reality
              if (node.Attributes.Contains("alt")) {
                outText.Write('[' + node.Attributes["alt"].Value);
                endElementString = "]";
              if (node.Attributes.Contains("src")) {
                outText.Write('<' + node.Attributes["src"].Value + '>');
              isInline = true;
              isInline = true;
          if (!skip && node.HasChildNodes) {
            ConvertContentTo(node, outText, isInline ? textInfo : new PreceedingDomTextInfo(textInfo.IsFirstTextOfDocWritten) { ListIndex = listIndex });
          if (endElementString != null) {
  internal class PreceedingDomTextInfo {
    public PreceedingDomTextInfo(BoolWrapper isFirstTextOfDocWritten) {
      IsFirstTextOfDocWritten = isFirstTextOfDocWritten;
    public bool WritePrecedingWhiteSpace { get; set; }
    public bool LastCharWasSpace { get; set; }
    public readonly BoolWrapper IsFirstTextOfDocWritten;
    public int ListIndex { get; set; }
  internal class BoolWrapper {
    public BoolWrapper() { }
    public bool Value { get; set; }
    public static implicit operator bool(BoolWrapper boolWrapper) {
      return boolWrapper.Value;
    public static implicit operator BoolWrapper(bool boolWrapper) {
      return new BoolWrapper { Value = boolWrapper };

How to start up spring-boot application via command line?

A Spring Boot project configured through Maven can be run using the following command from the project source folder

mvn spring-boot:run

How to add image that is on my computer to a site in css or html?

No, Not if your website is on a remote server, i.e not on localhost.

PHP mailer multiple address

You need to call the AddAddress method once for every recipient. Like so:

$mail->AddAddress('[email protected]', 'Person One');
$mail->AddAddress('[email protected]', 'Person Two');
// ..

Better yet, add them as Carbon Copy recipients.

$mail->AddCC('[email protected]', 'Person One');
$mail->AddCC('[email protected]', 'Person Two');
// ..

To make things easy, you should loop through an array to do this.

$recipients = array(
   '[email protected]' => 'Person One',
   '[email protected]' => 'Person Two',
   // ..
foreach($recipients as $email => $name)
   $mail->AddCC($email, $name);

In Chart.js set chart title, name of x axis and y axis?

            // style={{ width: "50%", height: "50%" }}
              scales: {
                yAxes: [
                    scaleLabel: {
                      display: true,
                      labelString: "Probability",
                xAxes: [
                    scaleLabel: {
                      display: true,
                      labelString: "Hours",

Scrolling to an Anchor using Transition/CSS3

Here is a pure css solution using viewport units and variables that automatically scales to the device (and works on window resize). I added the following to Alex's solution:

        html,body {
            width: 100%;
            height: 100%;
            position: fixed;/* prevents scrolling */
            --innerheight: 100vh;/* variable 100% of viewport height */

        body {
            overflow: hidden; /* prevents scrolling */

        .panel {
            width: 100%;
            height: var(--innerheight); /* viewport height */

        a[ id= "galeria" ]:target ~ #main article.panel {
            -webkit-transform: translateY( calc(-1*var(--innerheight)) );
            transform: translateY( calc(-1*var(--innerheight)) );

        a[ id= "contacto" ]:target ~ #main article.panel {
            -webkit-transform: translateY( calc(-2*var(--innerheight)) );
            transform: translateY( calc(-2*var(--innerheight)) );

Get local IP address in Node.js

Google directed me to this question while searching for "Node.js get server IP", so let's give an alternative answer for those who are trying to achieve this in their Node.js server program (may be the case of the original poster).

In the most trivial case where the server is bound to only one IP address, there should be no need to determine the IP address since we already know to which address we bound it (for example, the second parameter passed to the listen() function).

In the less trivial case where the server is bound to multiple IP addresses, we may need to determine the IP address of the interface to which a client connected. And as briefly suggested by Tor Valamo, nowadays, we can easily get this information from the connected socket and its localAddress property.

For example, if the program is a web server:

var http = require("http")

http.createServer(function (req, res) {

And if it's a generic TCP server:

var net = require("net")

net.createServer(function (socket) {

When running a server program, this solution offers very high portability, accuracy and efficiency.

For more details, see:

Task.Run with Parameter(s)?

Idea is to avoid using a Signal like above. Pumping int values into a struct prevents those values from changing (in the struct). I had the following Problem: loop var i would change before DoSomething(i) was called (i was incremented at end of loop before ()=> DoSomething(i,ii) was called). With the structs it doesn't happen anymore. Nasty bug to find: DoSomething(i, ii) looks great, but never sure if it gets called each time with a different value for i (or just a 100 times with i=100), hence -> struct

struct Job { public int P1; public int P2; }
for (int i = 0; i < 100; i++) {
    var job = new Job { P1 = i, P2 = i * i}; // structs immutable...
    Task.Run(() => DoSomething(job));

Remove Duplicates from range of cells in excel vba

If you got only one column in the range to clean, just add "(1)" to the end. It indicates in wich column of the range Excel will remove the duplicates. Something like:

 Sub norepeat()

    Range("C8:C16").RemoveDuplicates (1)

End Sub


Spring Boot + JPA : Column name annotation ignored

Turns out that I just have to convert @column name testName to all small letters, since it was initially in camel case.

Although I was not able to use the official answer, the question was able to help me solve my problem by letting me know what to investigate.


private String testName;


private String testName;

How to loop through an array of objects in swift

Your userPhotos array is option-typed, you should retrieve the actual underlying object with ! (if you want an error in case the object isn't there) or ? (if you want to receive nil in url):

let userPhotos = currentUser?.photos

for var i = 0; i < userPhotos!.count ; ++i {
    let url = userPhotos![i].url

But to preserve safe nil handling, you better use functional approach, for instance, with map, like this:

let urls = userPhotos?.map{ $0.url }

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '...' is therefore not allowed access

Why the error is raised:

JavaScript code is limited by the same-origin policy, meaning, from a page at, you can only make (AJAX) requests to services located at exactly the same domain, in that case, exactly (not - without the www - or

In your case, your Ajax code is trying to reach a service in from a page located at

Although very similar, they are not the same domain. And when they are not on the same domain, the request will only be successful if the target's respose contains a Access-Control-Allow-Origin header in it.

As your page/service at was never configured to present such header, that error message is shown.


As said, the origin (where the page with JavaScript is at) and the target (where the JavaScript is trying to reach) domains must be the exact same.

Your case seems like a typo. Looks like and are actually the same server/domain. So to fix, type the target and the origin equally: make you Ajax code request pages/services to not (Maybe place the target URL relatively, like '/login.php', without the domain).

On a more general note:

If the problem is not a typo like the one of this question seems to be, the solution would be to add the Access-Control-Allow-Origin to the target domain. To add it, depends, of course, of the server/language behind that address. Sometimes a configuration variable in the tool will do the trick. Other times you'll have to add the headers through code yourself.

Create a HTML table where each TR is a FORM

You can use the form attribute id to span a form over multiple elements each using the form attribute with the name of the form as follows:

               <form method="POST" id="form-1" action="/submit/form-1"></form>
               <input name="a" form="form-1">
          <td><input name="b" form="form-1"></td>
          <td><input name="c" form="form-1"></td>
          <td><input type="submit" form="form-1"></td>

How can I add a box-shadow on one side of an element?

Yes, you can use the shadow spread property of the box-shadow rule:

  border: 1px solid #333;_x000D_
  width: 100px;_x000D_
  height: 100px;_x000D_
  box-shadow: 10px 0 5px -2px #888;_x000D_
<div class="myDiv"></div>

The fourth property there -2px is the shadow spread, you can use it to change the spread of the shadow, making it appear that the shadow is on one side only.

This also uses the shadow positioning rules 10px sends it to the right (horizontal offset) and 0px keeps it under the element (vertical offset.)

5px is the blur radius :)

Example for you here.

Padding is invalid and cannot be removed?

Make sure that the keys you use to encrypt and decrypt are the same. The padding method even if not explicitly set should still allow for proper decryption/encryption (if not set they will be the same). However if you for some reason are using a different set of keys for decryption than used for encryption you will get this error:

Padding is invalid and cannot be removed

If you are using some algorithm to dynamically generate keys that will not work. They need to be the same for both encryption and decryption. One common way is to have the caller provide the keys in the constructor of the encryption methods class, to prevent the encryption/decryption process having any hand in creation of these items. It focuses on the task at hand (encrypting and decrypting data) and requires the iv and key to be supplied by the caller.

How to only get file name with Linux 'find'?

On mac (BSD find) use:

find /dir1 -type f -exec basename {} \;

How do I test for an empty JavaScript object?

I know this doesn't answer 100% your question, but I have faced similar issues before and here's how I use to solve them:

I have an API that may return an empty object. Because I know what fields to expect from the API, I only check if any of the required fields are present or not.

For example:

API returns {} or {agentID: '1234' (required), address: '1234 lane' (opt),...}. In my calling function, I'll only check

if( && { 
  do something with my agentID 
} else { 
  is empty response

This way I don't need to use those expensive methods to check if an object is empty. The object will be empty for my calling function if it doesn't have the agentID field.

How to check if a file exists in Documents folder?

NSArray *directoryPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString *imagePath =  [directoryPath objectAtIndex:0];
//If you have superate folder
imagePath= [imagePath stringByAppendingPathComponent:@"ImagesFolder"];//Get docs dir path with folder name
_imageName = [_imageName stringByAppendingString:@".jpg"];//Assign image name
imagePath= [imagePath stringByAppendingPathComponent:_imageName];
NSLog(@"%@", imagePath);

//Method 1:
BOOL file = [[NSFileManager defaultManager] fileExistsAtPath: imagePath];
if (file == NO){
    NSLog("File not exist");
} else {
    NSLog("File exist");

//Method 2:
NSData *data = [NSData dataWithContentsOfFile:imagePath];
UIImage *image = [UIImage imageWithData:data];
if (!(image == nil)) {//Check image exist or not
    cell.photoImageView.image = image;//Display image

Missing maven .m2 folder

When you first install maven, .m2 folder will not be present in C:\Users\ {user} path. To generate the folder you have to run any maven command e.g. mvn clean, mvn install etc. so that it searches for settings.xml in .m2 folder and when not found creates one.

So long story cur short, open cmd -> mvn install

It will show could not find any projects(Don't worry maven is working fine :P) now check your user folder.

P.S. If still not able to view .m2 folder try unhiding hidden items.

How can I send and receive WebSocket messages on the server side?

Clojure, the decode function assumes frame is sent as map of {:data byte-array-buffer :size int-size-of-buffer}, because the actual size may not be the same size as the byte-array depending on chunk size of your inputstream.

Code posted here:

(defn ws-decode [frame]
  "decodes websocket frame"
  (let [data (:data frame)
        dlen (bit-and (second data) 127)
        mstart (if (== dlen 127) 10 (if (== dlen 126) 4 2))
        mask (drop 2 (take (+ mstart 4) data))
        msg (make-array Byte/TYPE (- (:size frame) (+ mstart 4)))]
   (loop [i (+ mstart 4), j 0]
      (aset-byte msg j (byte (bit-xor (nth data i) (nth mask (mod j 4)))))
      (if (< i (dec(:size frame))) (recur (inc i) (inc j))))

(defn ws-encode [data]
  "takes in bytes, return websocket frame"
  (let [len (count data)
        blen (if (> len 65535) 10 (if (> len 125) 4 2))
        buf (make-array Byte/TYPE (+ len blen))
        _ (aset-byte buf 0 -127) ;;(bit-or (unchecked-byte 0x80) 
                                           (unchecked-byte 0x1)
        _ (if (= 2 blen) 
            (aset-byte buf 1 len) ;;mask 0, len
              (dorun(map #(aset-byte buf %1 
                      (unchecked-byte (bit-and (bit-shift-right len (*(- %2 2) 8))
                      (range 2 blen) (into ()(range 2 blen))))
              (aset-byte buf 1 (if (> blen 4) 127 126))))
        _ (System/arraycopy data 0 buf blen len)]

How to create file execute mode permissions in Git on Windows?

I have no touch and chmod command in my cmd.exe and git update-index --chmod=+x doesn't work for me.

I finally resolve it by setting skip-worktree bit:

git update-index --skip-worktree --chmod=+x

Date to milliseconds and back to date in Swift

Unless you absolutely have to convert the date to an integer, consider using a Double instead to represent the time interval. After all, this is the type that timeIntervalSince1970 returns. All of the answers that convert to integers loose sub-millisecond precision, but this solution is much more accurate (although you will still lose some precision due to floating-point imprecision).

public extension Date {
    /// The interval, in milliseconds, between the date value and
    /// 00:00:00 UTC on 1 January 1970.
    /// Equivalent to `self.timeIntervalSince1970 * 1000`.
    var millisecondsSince1970: Double {
        return self.timeIntervalSince1970 * 1000

     Creates a date value initialized relative to 00:00:00 UTC
     on 1 January 1970 by a given number of **milliseconds**.
     equivalent to
     self.init(timeIntervalSince1970: TimeInterval(milliseconds) / 1000)
     - Parameter millisecondsSince1970: A time interval in milliseconds.
    init(millisecondsSince1970: Double) {
        self.init(timeIntervalSince1970: TimeInterval(milliseconds) / 1000)


proper name for python * operator?

The Python Tutorial simply calls it 'the *-operator'. It performs unpacking of arbitrary argument lists.

milliseconds to time in javascript

This worked for me:

var dtFromMillisec = new Date(secs*1000);
var result = dtFromMillisec.getHours() + ":" + dtFromMillisec.getMinutes() + ":" + dtFromMillisec.getSeconds();


How to overload functions in javascript?

How about using spread operator as a parameter? The same block can be called with Multiple parameters. All the parameters are added into an array and inside the method you can loop in based on the length.

    function mName(...opt){
    mName(1,2,3,4); //[1,2,3,4]
    mName(1,2,3); //[1,2,3]

How to do multiple conditions for single If statement

As Hogan notes above, use an AND instead of &. See this tutorial for more info.

What's wrong with foreign keys?

I'll echo what Dmitriy said, but adding on a point.

I worked on a batch billing system that needed to insert large sets of rows on 30+ tables. We weren't allowed to do a data pump (Oracle) so we had to do bulk inserts. Those tables had foreign keys on them, but we had already ensured that they were not breaking any relationships.

Before insert, we disable the foreign key constraints so that Oracle doesn't take forever doing the inserts. After the insert is successful, we re-enable the constraints.

PS: In a large database with many foreign keys and child row data for a single record, sometimes foreign keys can be bad, and you may want to disallow cascading deletes. For us in the billing system, it would take too long and be too taxing on the database if we did cascading deletes, so we just mark the record as bad with a field on the main driver (parent) table.

Python re.sub(): how to substitute all 'u' or 'U's with 'you'

Another possible solution I came up with was:

re.sub(r'([uU]+(.)?\s)',' you ', text)

What are the differences among grep, awk & sed?

I just want to mention a thing, there are many tools can do text processing, e.g. sort, cut, split, join, paste, comm, uniq, column, rev, tac, tr, nl, pr, head, tail.....

they are very handy but you have to learn their options etc.

A lazy way (not the best way) to learn text processing might be: only learn grep , sed and awk. with this three tools, you can solve almost 99% of text processing problems and don't need to memorize above different cmds and options. :)

AND, if you 've learned and used the three, you knew the difference. Actually, the difference here means which tool is good at solving what kind of problem.

a more lazy way might be learning a script language (python, perl or ruby) and do every text processing with it.

Waiting for background processes to finish before exiting script

If you want to wait for jobs to finish, use wait. This will make the shell wait until all background jobs complete. However, if any of your jobs daemonize themselves, they are no longer children of the shell and wait will have no effect (as far as the shell is concerned, the child is already done. Indeed, when a process daemonizes itself, it does so by terminating and spawning a new process that inherits its role).

{ sleep 5; echo waking up after 5 seconds; } &
{ sleep 1; echo waking up after 1 second; } &
echo all jobs are done!

How can I select rows with most recent timestamp for each key value?

You can join the table with itself (on sensor id), and add left.timestamp < right.timestamp as join condition. Then you pick the rows, where is null. Voila, you got the latest entry per sensor.!9/45147/37

SELECT L.* FROM sensorTable L
LEFT JOIN sensorTable R ON
L.sensorID = R.sensorID AND
L.timestamp < R.timestamp
WHERE isnull (R.sensorID)

But please note, that this will be very resource intensive if you have a little amount of ids and many values! So, I wouldn't recommend this for some sort of Measuring-Stuff, where each Sensor collects a value every minute. However in a Use-Case, where you need to track "Revisions" of something that changes just "sometimes", it's easy going.

How to connect to a secure website using SSL in Java with a pkcs12 file?

It appears that you are extracting you certificate from the PKCS #12 key store and creating a new Java key store (with type "JKS"). You don't strictly have to provide a trust store password (although using one allows you to test the integrity of your root certificates).

So, try your program with only the following SSL properties set. The list shown in your question is over-specified and may be causing problems.

System.setProperty("", "myTrustStore");
System.setProperty("", "changeit");

Also, using the PKCS #12 file directly as the trust store should work, as long as the CA certificate is detected as a "trusted" entry. But in that case, you'll have to specify the property as "PKCS12" too.

Try with these properties only. If you get the same error, I suspect your problem is not the key store. If it still occurs, post more of the stack trace in your question to narrow the problem down.

The new error, "the trustAnchors parameter must be non-empty," could be due to setting the property to a file that doesn't exist; if the file cannot be opened, an empty key store created, which would lead to this error.

SQL Server principal "dbo" does not exist,

In my case I got this error when trying to impersonate as another user. E.g.

EXEC AS USER = 'dbo';

And as the database was imported from another environment, some of its users did not match the SQL Server logins.

You can check if you have the same problem by running the (deprecated) sp_change_users_login (in "Report" mode), or use the following query:

select,p.sid "sid in DB", (select serp.sid from sys.server_principals serp where = "sid in server"
from sys.database_principals p
where p.type in ('G','S','U')
and p.authentication_type = 1
and p.sid not in (select sid from sys.server_principals)

If in that list shows the user you are trying to impersonate, then you probably can fix it by assigning the DB user to the proper login in your server. For instance:


How to hide a button programmatically?

public void OnClick(View.v)
Button b1 = (Button) findViewById(;

Determine distance from the top of a div to top of window with javascript

You can use .offset() to get the offset compared to the document element and then use the scrollTop property of the window element to find how far down the page the user has scrolled:

var scrollTop     = $(window).scrollTop(),
    elementOffset = $('#my-element').offset().top,
    distance      = (elementOffset - scrollTop);

The distance variable now holds the distance from the top of the #my-element element and the top-fold.

Here is a demo:

Note that negative values mean that the element is above the top-fold.

Powershell equivalent of bash ampersand (&) for forking/running background processes

As long as the command is an executable or a file that has an associated executable, use Start-Process (available from v2):

Start-Process -NoNewWindow ping

You can also add this as a function in your profile:

function bg() {Start-Process -NoNewWindow @args}

and then the invocation becomes:

bg ping

In my opinion, Start-Job is an overkill for the simple use case of running a process in the background:

  1. Start-Job does not have access to your existing scope (because it runs in a separate session). You cannot do "Start-Job {notepad $myfile}"
  2. Start-Job does not preserve the current directory (because it runs in a separate session). You cannot do "Start-Job {notepad myfile.txt}" where myfile.txt is in the current directory.
  3. The output is not displayed automatically. You need to run Receive-Job with the ID of the job as parameter.

NOTE: Regarding your initial example, "bg sleep 30" would not work because sleep is a Powershell commandlet. Start-Process only works when you actually fork a process.

Android: adbd cannot run as root in production builds

For those who rooted the Android device with Magisk, you can install adb_root from Then adb root can run smoothly.

Java collections convert a string to a list of characters

Create an empty list of Character and then make a loop to get every character from the array and put them in the list one by one.

List<Character> characterList = new ArrayList<Character>();
char arrayChar[] = abc.toCharArray();
for (char aChar : arrayChar) 
    characterList.add(aChar); //  autoboxing 

SQL Query - Concatenating Results into One String

DECLARE @CodeNameString varchar(max)
SET @CodeNameString=''

SELECT @CodeNameString=@CodeNameString+CodeName FROM AccountCodes ORDER BY Sort
SELECT @CodeNameString

MySQL Multiple Joins in one query?

Just add another join:

SELECT dashboard_data.headline,
FROM dashboard_data 
    INNER JOIN dashboard_messages
            ON dashboard_message_id = 
    INNER JOIN images
            ON dashboard_messages.image_id = images.image_id

Format datetime in mvc 4

Thanks Darin, For me, to be able to post to the create method, It only worked after I modified the BindModel code to :

public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    var displayFormat = bindingContext.ModelMetadata.DisplayFormatString;
    var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);

    if (!string.IsNullOrEmpty(displayFormat) && value != null)
        DateTime date;
        displayFormat = displayFormat.Replace("{0:", string.Empty).Replace("}", string.Empty);
        // use the format specified in the DisplayFormat attribute to parse the date
         if (DateTime.TryParse(value.AttemptedValue, CultureInfo.GetCultureInfo("en-GB"), DateTimeStyles.None, out date))
            return date;
                string.Format("{0} is an invalid date format", value.AttemptedValue)

    return base.BindModel(controllerContext, bindingContext);

Hope this could help someone else...

Gradle Sync failed could not find constraint-layout:1.0.0-alpha2


constraint layout dependency

works for me

jQuery or CSS selector to select all IDs that start with some string

You can use meta characters like * ( So I think you just can use $('#player_*').

In your case you could also try the "Attribute starts with" selector: $('div[id^="player_"]')

Fatal error: Can't open and lock privilege tables: Table '' doesn't exist

When download mysql zip version, if run mysqld directly, you'll get this error: 2016-02-18T07:23:48.318481Z 0 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist 2016-02-18T07:23:48.319482Z 0 [ERROR] Aborting

You have to run below command first: mysqld --initialize

Make sure your data folder is empty before this command.

Vertical Alignment of text in a table cell

td.description {vertical-align: top;}

where description is the class name of the td with that text in it

td.description {_x000D_
  vertical-align: top;_x000D_
<td class="description">Description</td>

OR inline (yuk!)

<td style="vertical-align: top;">Description</td>

Copy from one workbook and paste into another

This should do it, let me know if you have trouble with it:

Sub foo()
Dim x As Workbook
Dim y As Workbook

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Now, copy what you want from x:
x.Sheets("name of copying sheet").Range("A1").Copy

'Now, paste to y worksheet:

'Close x:

End Sub

Alternatively, you could just:

Sub foo2()
Dim x As Workbook
Dim y As Workbook

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Now, transfer values from x to y:
y.Sheets("sheetname").Range("A1").Value = x.Sheets("name of copying sheet").Range("A1") 

'Close x:

End Sub

To extend this to the entire sheet:

With x.Sheets("name of copying sheet").UsedRange
    'Now, paste to y worksheet:
    y.Sheets("sheet name").Range("A1").Resize( _
        .Rows.Count, .Columns.Count) = .Value
End With

And yet another way, store the value as a variable and write the variable to the destination:

Sub foo3()
Dim x As Workbook
Dim y As Workbook
Dim vals as Variant

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Store the value in a variable:
vals = x.Sheets("name of sheet").Range("A1").Value

'Use the variable to assign a value to the other file/sheet:
y.Sheets("sheetname").Range("A1").Value = vals 

'Close x:

End Sub

The last method above is usually the fastest for most applications, but do note that for very large datasets (100k rows) it's observed that the Clipboard actually outperforms the array dump:

Copy/PasteSpecial vs Range.Value = Range.Value

That said, there are other considerations than just speed, and it may be the case that the performance hit on a large dataset is worth the tradeoff, to avoid interacting with the Clipboard.

Sort dataGridView columns in C# ? (Windows Form)



Easy way is to use Let keyword. This works for me.

from AItem in Db.A
Let BItem = Db.B.Where(x => == ).FirstOrDefault() 
Where SomeCondition
Select new YourViewModel
    X1 = AItem.a,
    X2 = AItem.b,
    X3 = BItem.c

This is a simulation of Left Join. If each item in B table not match to A item , BItem return null


The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).

WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.

For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:

enter image description here Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the MVC.

Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.

In the scenarios listed below you should go for WCF:

  1. If you need to send data on protocols like TCP, MSMQ or MIME
  2. If the consuming client just knows how to consume SOAP messages

WEB API is a framework for developing RESTful/HTTP services.

There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.

HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.

Using Javascript in CSS

I ran into a similar problem and have developed two standalone tools to accomplish this:

  • CjsSS.js is a Vanilla Javascript tool (so no external dependencies) that supports back to IE6.

  • ngCss is an Angular Module+Filter+Factory (aka: plugin) that supports Angular 1.2+ (so back to IE8)

Both of these tool sets allow you to do this in a STYLE tag or within an external *.css file:

    /*<script src='some.js'></script>
        var mainColor = "#cccccc";

    BODY {
        color: /*{{mainColor}}*/;

And this in your on-page style attributes:

    <div style="color: {{mainColor}}" cjsss="#sourceCSS">blah</div>


    <div style="color: {{mainColor}}" ng-css="sourceCSS">blah</div>

NOTE: In ngCss, you could also do $scope.mainColor in place of var mainColor

By default, the Javascript is executed in a sandboxed IFRAME, but since you author your own CSS and host it on your own server (just like your *.js files) then XSS isn't an issue. But the sandbox provides that much more security and peace of mind.

CjsSS.js and ngCss fall somewhere in-between the other tools around to accomplish similar tasks:

  • LESS, SASS and Stylus are all Preprocessors only and require you to learn a new language and mangle your CSS. Basically they extended CSS with new language features. All are also limited to plugins developed for each platform while CjsSS.js and ngCss both allow you to include any Javascript library via <script src='blah.js'></script> straight in your CSS!

  • AbsurdJS saw the same problems and went the exact opposite direction of the Preprocessors above; rather than extending CSS, AbsurdJS created a Javascript library to generate CSS.

CjsSS.js and ngCss took the middle ground; you already know CSS, you already know Javascript, so just let them work together in a simple, intuitive way.

How do you check if a certain index exists in a table?

To check Clustered Index exist on particular table or not:

SELECT * FROM SYS.indexes 

Error:Execution failed for task ':app:processDebugResources'. > Could not delete folder "" in android studio

React Native

In my case I just refresh ( http://localhost:8081/debugger-ui/ ) , and it works... Any other solutions didn't work for me. Perhaps some files are used by debuger and it can't delete them... Anyway, it works for me. Please try this and give a feedback.

How to process images of a video, frame by frame, in video streaming using OpenCV and Python

According to the latest updates for OpenCV 3.0 and higher, you need to change the Property Identifiers as follows in the code by Mehran:



and same applies to cv2.CAP_PROP_POS_FRAME_COUNT.

Hope it helps.

SQL How to remove duplicates within select query?

here is the solution for your query returning only one row for each date in that table here in the solution 'tony' will occur twice as two different start dates are there for it


How to visualize an XML schema?

XSD Diagram is free (GNU open license), doesn't need to be built, and gives an interactive diagram. You just open the file and Add the types you want on the (initially blank) diagram. Pretty straight forward.

enter image description here

create a text file using javascript

From a web page this cannot work since IE restricts the use of that object.

Asynchronously load images with jQuery


I came accross usecases where the onload handlers were not the right choice. In my case when printing via javascript. So there are actually two options to use AJAX style for this:

Solution 1

Use Base64 image data and a REST image service. If you have your own webservice, you can add a JSP/PHP REST script that offers images in Base64 encoding. Now how is that useful? I came across a cool new syntax for image encoding:

<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhE..."/>

So you can load the Image Base64 data using Ajax and then on completion you build the Base64 data string to the image! Great fun :). I recommend to use this site for image encoding.

    url : 'BASE64_IMAGE_REST_URL', 
    processData : false,
    $("#IMAGE_ID").attr("src", "data:image/png;base64,"+b64data);


Trick the browser to use its cache. This gives you a nice fadeIn() when the resource is in the browsers cache:

var url = 'IMAGE_URL';
    url : url, 
    cache: true,
    processData : false,
    $("#IMAGE_ID").attr("src", url).fadeIn();

However, both methods have its drawbacks: The first one only works on modern browsers. The second one has performance glitches and relies on assumption how the cache will be used.

cheers, will

How to clean old dependencies from maven repositories?

It's been more than 6 years since the question was asked, but I didn't find any tool to clean up my repository. So I wrote one myself in python to get rid of old jars. Maybe it will be useful for someone:

from os.path import isdir
from os import listdir
import re
import shutil

dry_run = False #  change to True to get a log of what will be removed
m2_path = '/home/jb/.m2/repository/' #  here comes your repo path
version_regex = '^\d[.\d]*$'

def check_and_clean(path):
    files = listdir(path)
    for file in files:
        if not isdir('/'.join([path, file])):
    last = check_if_versions(files)
    if last is None:
        for file in files:
            check_and_clean('/'.join([path, file]))
    elif len(files) == 1:
        print('update ' + path.split(m2_path)[1])
        for file in files:
            if file == last:
            print(file + ' (newer version: ' + last + ')')
            if not dry_run:
                shutil.rmtree('/'.join([path, file]))

def check_if_versions(files):
    if len(files) == 0:
        return None
    last = ''
    for file in files:
        if re.match(version_regex, file):
            if last == '':
                last = file
            if len(last.split('.')) == len(file.split('.')):
                for (current, new) in zip(last.split('.'), file.split('.')):
                    if int(new) > int(current):
                        last = file
                    elif int(new) < int(current):
                return None
            return None
    return last


It recursively searches within the .m2 repository and if it finds a catalog where different versions reside it removes all of them but the newest.

Say you have the following tree somewhere in your .m2 repo:

+-- antlr
    +-- 2.7.2
    ¦   +-- antlr-2.7.2.jar
    ¦   +-- antlr-2.7.2.jar.sha1
    ¦   +-- antlr-2.7.2.pom
    ¦   +-- antlr-2.7.2.pom.sha1
    ¦   +-- _remote.repositories
    +-- 2.7.7
        +-- antlr-2.7.7.jar
        +-- antlr-2.7.7.jar.sha1
        +-- antlr-2.7.7.pom
        +-- antlr-2.7.7.pom.sha1
        +-- _remote.repositories

Then the script removes version 2.7.2 of antlr and what is left is:

+-- antlr
    +-- 2.7.7
        +-- antlr-2.7.7.jar
        +-- antlr-2.7.7.jar.sha1
        +-- antlr-2.7.7.pom
        +-- antlr-2.7.7.pom.sha1
        +-- _remote.repositories

If any old version, that you actively use, will be removed. It can easily be restored with maven (or other tools that manage dependencies).

You can get a log of what is going to be removed without actually removing it by setting dry_run = False. The output will go like this:

update /org/projectlombok/lombok
1.18.2 (newer version: 1.18.6)
1.16.20 (newer version: 1.18.6)

This means, that versions 1.16.20 and 1.18.2 of lombok will be removed and 1.18.6 will be left untouched.

The file can be found on my github (the latest version).

Resetting MySQL Root Password with XAMPP on Localhost


1 - Start the Apache Server and MySQL instances from the XAMPP control panel.

2 - After the server started, open any web browser and give http://localhost/phpmyadmin/. This will open the phpMyAdmin interface. Using this interface we can manage the MySQL server from the web browser.

3 - In the phpMyAdmin window, select SQL tab from the top panel. This will open the SQL tab where we can run the SQL queries.

4 - Now type the following query in the text area and click Go

UPDATE mysql.user SET Password=PASSWORD('password') WHERE User='root'; FLUSH PRIVILEGES;

5 - Now you will see a message saying some thing like: the query has been executed successfully.

6 - If you refresh the page, you will be getting a error message. This is because the phpMyAdmin configuration file is not aware of our newly set root passoword. To do this we have to modify the phpMyAdmin config file.

7 - Open the file [XAMPP Installation Path]/phpmyadmin/ in your favorite text editor (e.g: C:\xampp\phpMyAdmin\

8 - Search for the string

$cfg['Servers'][$i]['password'] = '';

and change it to like this,

$cfg['Servers'][$i]['password'] = 'password';

Here the ‘password’ is what we set to the root user using the SQL query.

9 - Now all set to go. Save the file and restart the XAMPP apache and mysql servers. It should work!



Convert Dictionary<string,string> to semicolon separated string in c#

For Linq to work over Dictionary you need at least .Net v3.5 and using System.Linq;.

Some alternatives:

string myDesiredOutput = string.Join(";", myDict.Select(x => string.Join("=", x.Key, x.Value)));


string myDesiredOutput = string.Join(";", myDict.Select(x => $"{x.Key}={x.Value}"));

If you can't use Linq for some reason, use Stringbuilder:

StringBuilder sb = new StringBuilder();
var isFirst = true;
foreach(var x in myDict) 
  if (isFirst) 
    isFirst = false;

string myDesiredOutput = sb.ToString(); 



How does RewriteBase work in .htaccess

I believe this excerpt from the Apache documentation, complements well the previous answers :

This directive is required when you use a relative path in a substitution in per-directory (htaccess) context unless either of the following conditions are true:

  • The original request, and the substitution, are underneath the DocumentRoot (as opposed to reachable by other means, such as Alias).

  • The filesystem path to the directory containing the RewriteRule, suffixed by the relative substitution is also valid as a URL path on the server (this is rare).

As previously mentioned, in other contexts, it is only useful to make your rule shorter. Moreover, also as previously mentioned, you can achieve the same thing by placing the htaccess file in the subdirectory.

Set Background color programmatically

The previous answers are now deprecated, you need to use ContextCompat.getColor to retrieve the color properly:

root.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.white));

Jupyter notebook not running code. Stuck on In [*]

I have installed jupyter with command pip3 install jupyter and have the same problem. when instead I used the command pip3 install jupyter ipython the problem was fixed.

How to write inline if statement for print?

Try this . It might help you


if b:
   print a

Is there an advantage to use a Synchronized Method instead of a Synchronized Block?

With synchronized blocks, you can have multiple synchronizers, so that multiple simultaneous but non-conflicting things can go on at the same time.

Select row and element in awk

Since awk and perl are closely related...

Perl equivalents of @Dennis's awk solutions:

To print the second line:
perl -ne 'print if $. == 2' file

To print the second field:
perl -lane 'print $F[1]' file

To print the third field of the fifth line:
perl -lane 'print $F[2] if $. == 5' file

Perl equivalent of @Glenn's solution:

Print the j'th field of the i'th line

perl -lanse 'print $F[$j-1] if $. == $i' -- -i=5 -j=3 file

Perl equivalents of @Hai's solutions:

if you are looking for second columns that contains abc:

perl -lane 'print if $F[1] =~ /abc/' foo

... and if you want to print only a particular column:

perl -lane 'print $F[2] if $F[1] =~ /abc/' foo

... and for a particular line number:

perl -lane 'print $F[2] if $F[1] =~ /abc/ && $. == 5' foo

-l removes newlines, and adds them back in when printing
-a autosplits the input line into array @F, using whitespace as the delimiter
-n loop over each line of the input file
-e execute the code within quotes
$F[1] is the second element of the array, since Perl starts at 0
$. is the line number

Generate a random number in the range 1 - 10

Actually I don't know you want to this.

try this

INSERT INTO my_table (my_column)
    (random() * 10) + 1

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

For beginners: To create your .bash_profile file in your home directory on MacOS, run:

nano ~/.bash_profile

Then you can paste in the following:

As you can see, it includes some example aliases and an environment variable at the bottom.

One you're done making your changes, follow the instructions at the bottom of the Nano editor window to WriteOut (Ctrl-O) and Exit (Ctrl-X). Then quit your Terminal and reopen it, and you will be able to use your newly defined aliases and environment variables.

PHP - Get bool to echo false when false

I like this one to print that out

var_dump ($var);

Iif equivalent in C#

booleanExpression ? trueValue : falseValue;


string itemText = count > 1 ? "items" : "item";

set font size in jquery

You can try another way like that:

<div class="content">

jQuery code:

    background: "#d1d1d1",
    fontSize: "30px"

Now you can add more css property as you want.

SQL Server SELECT INTO @variable?

you can do this:

INTO #tempCustomer 
    CustomerId = @CustomerId

then later

SELECT CustomerId FROM #tempCustomer

you doesn't need to declare the structure of #tempCustomer

How do I simulate placeholder functionality on input date field?

You can do something like this:

<input onfocus="(this.type='date')" class="js-form-control" placeholder="Enter Date">

Add property to an array of objects

With ES6 you can simply do:

 for(const element of Results) {
      element.Active = "false";

Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError.

For gradle

    exclude module: 'log4j'
    exclude module: 'slf4j-log4j12'

How to convert md5 string to normal text?

I you send passwords to users in an email, you might as well have no passwords at all.

You cannot reverse the MD5 function, so your only option is to generate a new password and send that to the user (preferably over some secure channel).

What is the difference between dynamic programming and greedy approach?

With the reference of Biswajit Roy: Dynamic Programming firstly plans then Go. and Greedy algorithm uses greedy choice, it firstly Go then continuously Plans.

How can I find the number of days between two Date objects in Ruby?

irb(main):005:0> a = Date.parse("12/1/2010")
=> #<Date: 4911063/2,0,2299161>

irb(main):007:0> b = Date.parse("12/21/2010")
=> #<Date: 4911103/2,0,2299161>

irb(main):016:0> c = b.mjd - a.mjd
=> 20

This uses a Modified Julian Day Number.

From wikipedia:

The Julian date (JD) is the interval of time in days and fractions of a day since January 1, 4713 BC Greenwich noon, Julian proleptic calendar.

.NET NewtonSoft JSON deserialize map to a different property name

Json.NET has a JsonPropertyAttribute which allows you to specify the name of a JSON property, so your code should be:

public class TeamScore
    public string EightyMinScore { get; set; }
    public string HomeOrAway { get; set; }
    [JsonProperty("score ")]
    public string Score { get; set; }
    public string TeamId { get; set; }

public class Team
    public string v1 { get; set; }
    public TeamScore TeamScores { get; set; }

public class RootObject
    public List<Team> Team { get; set; }

Documentation: Serialization Attributes

Server.Transfer Vs. Response.Redirect

Transfer is entirely server-side. Client address bar stays constant. Some complexity about the transfer of context between requests. Flushing and restarting page handlers can be expensive so do your transfer early in the pipeline e.g. in an HttpModule during BeginRequest. Read the MSDN docs carefully, and test and understand the new values of HttpContext.Request - especially in Postback scenarios. We usually use Server.Transfer for error scenarios.

Redirect terminates the request with a 302 status and client-side roundtrip response with and internally eats an exception (minor server perf hit - depends how many you do a day) Client then navigates to new address. Browser address bar & history updates etc. Client pays the cost of an extra roundtrip - cost varies depending on latency. In our business we redirect a lot we wrote our own module to avoid the exception cost.

What does "The code generator has deoptimised the styling of [some file] as it exceeds the max of "100KB"" mean?

Either one of the below three options gets rid of the message (but for different reasons and with different side-effects I suppose):

  1. exclude the node_modules directory or explicitly include the directory where your app resides (which presumably does not contain files in excess of 100KB)
  2. set the Babel option compact to true (actually any value other than "auto")
  3. set the Babel option compact to false (see above)

#1 in the above list can be achieved by either excluding the node_modules directory or be explicitly including the directory where your app resides.

E.g. in webpack.config.js:

let path = require('path');
module: {
     loaders: [
          loader: 'babel',
          exclude: path.resolve(__dirname, 'node_modules/')

... or by using include: path.resolve(__dirname, 'app/') (again in webpack.config.js).

#2 and #3 in the above list can be accomplished by the method suggested in this answer or (my preference) by editing the .babelrc file. E.g.:

$ cat .babelrc 
    "presets": ["es2015", "react"],
    "compact" : true

Tested with the following setup:

$ npm ls --depth 0 | grep babel
+-- [email protected]
+-- [email protected]
+-- [email protected]
+-- [email protected]

How to open the second form?

Form1 OpenNewForm = new Form1();

"OpenNewForm" is the name of the Form. In the second the form opens.

If you want to close the previous form:


String comparison in Objective-C

You can use case-sensitive or case-insensitive comparison, depending what you need. Case-sensitive is like this:

if ([category isEqualToString:@"Some String"])
   // Both strings are equal without respect to their case.

Case-insensitive is like this:

if ([category compare:@"Some String" options:NSCaseInsensitiveSearch] == NSOrderedSame)
   // Both strings are equal with respect to their case.

SSL received a record that exceeded the maximum permissible length. (Error code: ssl_error_rx_record_too_long)

This error also occurs when you have enabled the SSL module (i.e. you have run e.g. a2enmod ssl) but not yet enabled any SSL site entries (i.e you have not run e.g. a2ensite default-ssl).

How do I convert 2018-04-10T04:00:00.000Z string to DateTime?

Update: Using DateTimeFormat, introduced in java 8:

The idea is to define two formats: one for the input format, and one for the output format. Parse with the input formatter, then format with the output formatter.

Your input format looks quite standard, except the trailing Z. Anyway, let's deal with this: "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'". The trailing 'Z' is the interesting part. Usually there's time zone data here, like -0700. So the pattern would be ...Z, i.e. without apostrophes.

The output format is way more simple: "dd-MM-yyyy". Mind the small y -s.

Here is the example code:

DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);
DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern("dd-MM-yyy", Locale.ENGLISH);
LocalDate date = LocalDate.parse("2018-04-10T04:00:00.000Z", inputFormatter);
String formattedDate = outputFormatter.format(date);
System.out.println(formattedDate); // prints 10-04-2018

Original answer - with old API SimpleDateFormat

SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
SimpleDateFormat outputFormat = new SimpleDateFormat("dd-MM-yyyy");
Date date = inputFormat.parse("2018-04-10T04:00:00.000Z");
String formattedDate = outputFormat.format(date);
System.out.println(formattedDate); // prints 10-04-2018

Sublime Text 2 Code Formatting

I can't speak for the 2nd or 3rd, but if you install Node first, Sublime-HTMLPrettify works pretty well. You have to setup your own key shortcut once it is installed. One thing I noticed on Windows, you may need to edit your path for Node in the %PATH% variable if it is already long (I think the limit is 1024 for the %PATH% variable, and anything after that is ignored.)

There is a Windows bug, but in the issues there is a fix for it. You'll need to edit the file -

Which HTML elements can receive focus?

Maybe this one can help:

function focus(el){_x000D_
 return el==document.activeElement;_x000D_

return value: true = success, false = failed


ActiveX component can't create object

I had the same issue with Excel, I was trying to use a 32 COM DLL with an Excel 64 bits version and I got this error. I rebuild the COM dll to a 64 bits version and the error disappears. So be sure that your COM dll has the same architecture (x86 vs x64) than your application.

How to call javascript function from button click event

If you don't need to initiate a post back when you press this button, then making the overhead of a server control isn't necesary.

<input id="addButton" type="button" value="Add" />

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

If you still need to be able to do a post back, you can conditionally stop the rest of the button actions with a little different code:

<asp:Button ID="buttonAdd" runat="server" Text="Add" />

<script type="text/javascript" language="javascript">
         $('#<%= buttonAdd.ClientID %>').click(function(e) 

             if(/*Some Condition Is Not Met*/) 
                return false;

The application may be doing too much work on its main thread

I had the same problem. Android Emulator worked perfectly on Android < 6.0. When I used emulator Nexus 5 (Android 6.0), the app worked very slow with I/Choreographer: Skipped frames in the logs.

So, I solved this problem by changing in Manifest file hardwareAccelerated option to true like this:

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

    <application android:hardwareAccelerated="true">

Stacked Bar Plot in R

A somewhat different approach using ggplot2:

dat <- read.table(text = "A   B   C   D   E   F    G
1 480 780 431 295 670 360  190
2 720 350 377 255 340 615  345
3 460 480 179 560  60 735 1260
4 220 240 876 789 820 100   75", header = TRUE)


dat$row <- seq_len(nrow(dat))
dat2 <- melt(dat, id.vars = "row")


ggplot(dat2, aes(x = variable, y = value, fill = row)) + 
  geom_bar(stat = "identity") +
  xlab("\nType") +
  ylab("Time\n") +
  guides(fill = FALSE) +

this gives:

enter image description here

When you want to include a legend, delete the guides(fill = FALSE) line.

convert php date to mysql format

If you know the format of date in $_POST[intake_date] you can use explode to get year , month and time and then concatenate to form a valid mySql date. for example if you are getting something like 12/15/1988 in date you can do like this

    $date = explode($_POST['intake_date'], '/');
    mysql_date = $date[2].'-'$date[1].'-'$date[0];

though if you have valid date date('y-m-d', strtotime($date)); should also work

Reading tab-delimited file with Pandas - works on Windows, but not on Mac

The biggest clue is the rows are all being returned on one line. This indicates line terminators are being ignored or are not present.

You can specify the line terminator for csv_reader. If you are on a mac the lines created will end with \rrather than the linux standard \n or better still the suspenders and belt approach of windows with \r\n.

pandas.read_csv(filename, sep='\t', lineterminator='\r')

You could also open all your data using the codecs package. This may increase robustness at the expense of document loading speed.

import codecs

doc ='document','rU','UTF-16') #open for reading with "universal" type set

df = pandas.read_csv(doc, sep='\t')

How to tell when UITableView has completed ReloadData?

Try this:

tableView.backgroundColor = .black


DispatchQueue.main.async(execute: {

    tableView.backgroundColor = .green


The tableView color will changed from black to green only after the reloadData() function completes.

Unable to merge dex

add commands below:

android {

    dexOptions {

        jumboMode true
        javaMaxHeapSize "4g"


Import JSON file in React

One nice way (without adding a fake .js extension which is for code not for data and configs) is to use json-loader module. If you have used create-react-app to scaffold your project, the module is already included, you just need to import your json:

import Profile from './components/profile';

This answer explains more.

Add timer to a Windows Forms application

Bit more detail:

    private void Form1_Load(object sender, EventArgs e)
        Timer MyTimer = new Timer();
        MyTimer.Interval = (45 * 60 * 1000); // 45 mins
        MyTimer.Tick += new EventHandler(MyTimer_Tick);

    private void MyTimer_Tick(object sender, EventArgs e)
        MessageBox.Show("The form will now be closed.", "Time Elapsed");

Proper usage of Optional.ifPresent()

You can use method reference like this:


Method ifPresent() get Consumer object as a paremeter and (from JavaDoc): "If a value is present, invoke the specified consumer with the value." Value it is your variable user.

Or if this method doSomethingWithUser is in the User class and it is not static, you can use method reference like this:


How to get index of an item in java.util.Set

After creating Set just convert it to List and get by index from List:

Set<String> stringsSet = new HashSet<>();

List<String> stringsList = new ArrayList<>(stringsSet);
stringsList.get(0); // "string1";
stringsList.get(1); // "string2";

How to Identify Microsoft Edge browser via CSS?

/* Microsoft Edge Browser 12-18 (All versions before Chromium) */

This one should work:

@supports (-ms-ime-align:auto) {
    .selector {
        property: value;

For more see: Browser Strangeness

How can I implement a theme from bootswatch or wrapbootstrap in an MVC 5 project?

The steps to apply a theme are fairly simple. To really understand how everything works together, you'll need to understand what the ASP.NET MVC 5 template is providing out of the box and how you can customize it for your needs.

Note: If you have a basic understanding of how the MVC 5 template works, scroll down to the theming section.

ASP.NET MVC 5 Template: How it works

This walk-through goes over how to create an MVC 5 project and what's going on under the hood. See all the features of MVC 5 Template in this blog.

  1. Create a new project. Under Templates Choose Web > ASP.NET Web Application. Enter a name for your project and click OK.

  2. On the next wizard, choose MVC and click OK. This will apply the MVC 5 template.

    Example of choosing MVC Template

  3. The MVC 5 template creates an MVC application that uses Bootstrap to provide responsive design and theming features. Under the hood, the template includes a bootstrap 3.* nuget package that installs 4 files: bootstrap.css, bootstrap.min.css, bootstrap.js, and bootstrap.min.js.

    Example of installed css and js

  4. Bootstrap is bundled in your application by using the Web Optimization feature. Inspect Views/Shared/_Layout.cshtml and look for




    These two paths refer to bundles set up in App_Start/BundleConfig.cs:

    bundles.Add(new ScriptBundle("~/bundles/bootstrap").Include(
    bundles.Add(new StyleBundle("~/Content/css").Include(
  5. This is what makes it possible to run your application without any configuring up front. Try running your project now.

    Default Application Running

Applying Bootstrap Themes in ASP.NET MVC 5

This walk-through covers how to apply bootstrap themes in an MVC 5 project

  1. First, download the css of the theme you'd like to apply. For this example, I'll be using Bootswatch's Flatly. Include the downloaded flatly.bootstrap.css and flatly.bootstrap.min.css in the Content folder (be sure to Include in Project as well).
  2. Open App_Start/BundleConfig.cs and change the following:

    bundles.Add(new StyleBundle("~/Content/css").Include(

    to include your new theme:

    bundles.Add(new StyleBundle("~/Content/css").Include(
  3. If you're using the default _Layout.cshtml included in the MVC 5 template, you can skip to step 4. If not, as a bare minimum, include these two line in your layout along with your Bootstrap HTML template:

    In your <head>:


    Last line before closing </body>:

  4. Try running your project now. You should see your newly created application now using your theme.

    Default template using flatly theme


Check out this awesome 30 day walk-through guide by James Chambers for more information, tutorials, tips and tricks on how to use Twitter Bootstrap with ASP.NET MVC 5.

detect key press in python?

More things can be done with keyboard module. You can install this module using pip install keyboard Here are some of the methods:

Method #1:

Using the function read_key():

import keyboard

while True:
    if keyboard.read_key() == "p":
        print("You pressed p")

This is gonna break the loop as the key p is pressed.

Method #2:

Using function wait:

import keyboard

print("You pressed p")

It will wait for you to press p and continue the code as it is pressed.

Method #3:

Using the function on_press_key:

import keyboard

keyboard.on_press_key("p", lambda _:print("You pressed p"))

It needs a callback function. I used _ because the keyboard function returns the keyboard event to that function.

Once executed, it will run the function when the key is pressed. You can stop all hooks by running this line:


Method #4:

This method is sort of already answered by user8167727 but I disagree with the code they made. It will be using the function is_pressed but in an other way:

import keyboard

while True:
    if keyboard.is_pressed("p"):
        print("You pressed p")

It will break the loop as p is pressed.


  • keyboard will read keypresses from the whole OS.
  • keyboard requires root on linux

How does "cat << EOF" work in bash?

Using tee instead of cat

Not exactly as an answer to the original question, but I wanted to share this anyway: I had the need to create a config file in a directory that required root rights.

The following does not work for that case:

$ sudo cat <<EOF >/etc/somedir/foo.conf
# my config file

because the redirection is handled outside of the sudo context.

I ended up using this instead:

$ sudo tee <<EOF /etc/somedir/foo.conf >/dev/null
# my config file

How to download image from url

Try this it worked for me

Write this in your Controller

public class DemoController: Controller

        public async Task<FileStreamResult> GetLogoImage(string logoimage)
            string str = "" ;
            var filePath = Server.MapPath("~/App_Data/" + SubfolderName);//If subfolder exist otherwise leave.
            // DirectoryInfo dir = new DirectoryInfo(filePath);
            string[] filePaths = Directory.GetFiles(@filePath, "*.*");
            foreach (var fileTemp in filePaths)
                  str= fileTemp.ToString();
                return File(new MemoryStream(System.IO.File.ReadAllBytes(str)), System.Web.MimeMapping.GetMimeMapping(str), Path.GetFileName(str));

Here is my view

<div><a href="/DemoController/GetLogoImage?Type=Logo" target="_blank">Download Logo</a></div>

Efficiently convert rows to columns in sql server

There are several ways that you can transform data from multiple rows into columns.


In SQL Server you can use the PIVOT function to transform the data from rows to columns:

select Firstname, Amount, PostalCode, LastName, AccountNumber
  select value, columnname
  from yourtable
) d
  for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;

See Demo.

Pivot with unknown number of columnnames

If you have an unknown number of columnnames that you want to transpose, then you can use dynamic SQL:

    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(ColumnName) 
                    from yourtable
                    group by ColumnName, id
                    order by id
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 

set @query = N'SELECT ' + @cols + N' from 
                select value, ColumnName
                from yourtable
            ) x
                for ColumnName in (' + @cols + N')
            ) p '

exec sp_executesql @query;

See Demo.

Using an aggregate function

If you do not want to use the PIVOT function, then you can use an aggregate function with a CASE expression:

  max(case when columnname = 'FirstName' then value end) Firstname,
  max(case when columnname = 'Amount' then value end) Amount,
  max(case when columnname = 'PostalCode' then value end) PostalCode,
  max(case when columnname = 'LastName' then value end) LastName,
  max(case when columnname = 'AccountNumber' then value end) AccountNumber
from yourtable

See Demo.

Using multiple joins

This could also be completed using multiple joins, but you will need some column to associate each of the rows which you do not have in your sample data. But the basic syntax would be:

select fn.value as FirstName,
  a.value as Amount,
  pc.value as PostalCode,
  ln.value as LastName,
  an.value as AccountNumber
from yourtable fn
left join yourtable a
  on fn.somecol = a.somecol
  and a.columnname = 'Amount'
left join yourtable pc
  on fn.somecol = pc.somecol
  and pc.columnname = 'PostalCode'
left join yourtable ln
  on fn.somecol = ln.somecol
  and ln.columnname = 'LastName'
left join yourtable an
  on fn.somecol = an.somecol
  and an.columnname = 'AccountNumber'
where fn.columnname = 'Firstname'

Shuffling a list of objects

random.shuffle should work. Here's an example, where the objects are lists:

from random import shuffle
x = [[i] for i in range(10)]

# print(x)  gives  [[9], [2], [7], [0], [4], [5], [3], [1], [8], [6]]
# of course your results will vary

Note that shuffle works in place, and returns None.