Programs & Examples On #Infowindow

The InfoWindow is a standard class within the Google Maps JavaScript API; it is an overlay that displays content in a floating window above the map and is anchored at a specified location on the map.

Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)

Just a speculation, I have not enough experience to try it... )-:

Since GoogleMap is a fragment, it should be possible to catch marker onClick event and show custom fragment view. A map fragment will be still visible on the background. Does anybody tried it? Any reason why it could not work?

The disadvantage is that map fragment would be freezed on backgroud, until a custom info fragment return control to it.

Marker content (infoWindow) Google Maps

Although this question has already been answered, I think this approach is better : extract from this question on StackOverFlow google maps - open marker infowindow given the coordinates:

Each marker gets an "infowindow" entry :

function createMarker(lat, lon, html) {
    var newmarker = new google.maps.Marker({
        position: new google.maps.LatLng(lat, lon),
        map: map,
        title: html

    newmarker['infowindow'] = new google.maps.InfoWindow({
            content: html

    google.maps.event.addListener(newmarker, 'mouseover', function() {
        this['infowindow'].open(map, this);

Google Maps API Multiple Markers with Infowindows

If you also want to bind closing of infowindow to some event, try something like this

google.maps.event.addListener(marker,'click', (function(marker,content,infowindow){ 
    return function() {
        google.maps.event.addListener(map,'click', function(){ 

Bootstrap number validation

Well I always use the same easy way and it works for me. In your HTML keep the type as text (like this):

<input type="text" class="textfield" value="" id="onlyNumbers" name="onlyNumbers" onkeypress="return isNumber(event)" onpaste="return false;"/>

After this you only need to add a method on javascript

<script type="text/javascript">     
function isNumber(evt) {
        evt = (evt) ? evt : window.event;
        var charCode = (evt.which) ? evt.which : evt.keyCode;
        if ( (charCode > 31 && charCode < 48) || charCode > 57) {
            return false;
        return true;

With this easy validation you will only get positive numbers as you wanted. You can modify the charCodes to add more valid keys to your method.

Here´s the code working: Only numbers validation

Delete all documents from index/type without deleting type

You can delete documents from type with following query:

POST /index/type/_delete_by_query
    "query" : { 
        "match_all" : {}

I tested this query in Kibana and Elastic 5.5.2

Calling startActivity() from outside of an Activity?

Sometimes this error can occur without an explicit call to startActivity(...). For example, some of you may have seen a stack trace like this in Crashlytics:

Fatal Exception: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
       at android.content.ContextWrapper.startActivity(
       at android.text.method.LinkMovementMethod.onTouchEvent(
       at android.widget.TextView.onTouchEvent(
       at android.view.View.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.widget.AbsListView.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.ViewGroup.dispatchTransformedTouchEvent(
       at android.view.ViewGroup.dispatchTouchEvent(
       at android.view.View.dispatchPointerEvent(
       at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(
       at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(
       at android.view.ViewRootImpl$InputStage.deliver(
       at android.view.ViewRootImpl$InputStage.onDeliverToNext(
       at android.view.ViewRootImpl$InputStage.forward(
       at android.view.ViewRootImpl$AsyncInputStage.forward(
       at android.view.ViewRootImpl$InputStage.apply(
       at android.view.ViewRootImpl$AsyncInputStage.apply(
       at android.view.ViewRootImpl$InputStage.deliver(
       at android.view.ViewRootImpl$InputStage.onDeliverToNext(
       at android.view.ViewRootImpl$InputStage.forward(
       at android.view.ViewRootImpl$InputStage.apply(
       at android.view.ViewRootImpl$InputStage.deliver(
       at android.view.ViewRootImpl.deliverInputEvent(
       at android.view.ViewRootImpl.doProcessInputEvents(
       at android.view.ViewRootImpl.enqueueInputEvent(
       at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(
       at android.view.InputEventReceiver.dispatchInputEvent(
       at android.os.MessageQueue.nativePollOnce(
       at android.os.Looper.loop(
       at java.lang.reflect.Method.invoke(
       at java.lang.reflect.Method.invoke(

And you may wonder what you did wrong, since the trace only includes framework code. Well, here's an example of how this can happen. Let's say we're in a fragment.

Activity activity = getActivity();
Context activityContext = activity;
Context appContext = activityContext.getApplicationContext();
LayoutInflater inflater = LayoutInflater.from(appContext); // whoops!
View view = inflater.inflate(R.layout.some_layout, parent, false);
TextView tvWithLinks = (TextView) view.findViewById(;

tvWithLinks.setMovementMethod(LinkMovementMethod.getInstance()); // whoops!!

Now, when a user clicks on that text view, your app will crash with the stack trace above. This is because the layout inflater has a reference to the application context, and so therefore your text view has an application context. Clicking on that text view implicitly calls appContext.startActivity(...).

Final note: I tested this on Android 4, 5, 6, and 7 devices. It only affects 4, 5, and 6. Android 7 devices apparently have no trouble calling appContext.startActivity(...).

I hope this helps someone else!

Converting pixels to dp

This should give you the conversion dp to pixels:

public static int dpToPx(int dp)
    return (int) (dp * Resources.getSystem().getDisplayMetrics().density);

This should give you the conversion pixels to dp:

public static int pxToDp(int px)
    return (int) (px / Resources.getSystem().getDisplayMetrics().density);

How can I get a vertical scrollbar in my ListBox?

Scroll Bar is added to the List box automatically unless its visibility is set to Hidden. Whenever the size of List Items exceeds the one, which can be shown inside a list box vertical or horizontal list box can be seen during the run time.

Android: How to set password property in an edit text?

Here's a new way of putting dots in password

    android:hint="@string/pwprompt" /

add android:inputType = "textPassword"

How to add 30 minutes to a JavaScript Date object?

I always create 7 functions, to work with date in JS:
addSeconds, addMinutes, addHours, addDays, addWeeks, addMonths, addYears.

You can see an example here:

How to use:

var now = new Date();

These are the functions:

Date.prototype.addSeconds = function(seconds) {
  this.setSeconds(this.getSeconds() + seconds);
  return this;

Date.prototype.addMinutes = function(minutes) {
  this.setMinutes(this.getMinutes() + minutes);
  return this;

Date.prototype.addHours = function(hours) {
  this.setHours(this.getHours() + hours);
  return this;

Date.prototype.addDays = function(days) {
  this.setDate(this.getDate() + days);
  return this;

Date.prototype.addWeeks = function(weeks) {
  return this;

Date.prototype.addMonths = function (months) {
  var dt = this.getDate();
  this.setMonth(this.getMonth() + months);
  var currDt = this.getDate();
  if (dt !== currDt) {  
  return this;

Date.prototype.addYears = function(years) {
  var dt = this.getDate();
  this.setFullYear(this.getFullYear() + years);
  var currDt = this.getDate();
  if (dt !== currDt) {  
  return this;

Django Rest Framework -- no module named rest_framework

Yeh for me it was the python version as well ...
much better to use pipenv ...
create a virtual env using using python 3 ...

install pipenv : pip3 install pipenv
create the virtualenv: pipenv --python 3
activate the virtual env: pipenv shell

Fatal error: unexpectedly found nil while unwrapping an Optional values

I don't know is it bug or something but your labels and other UIs does not initialized automatically when you use custom cell. You should try this in your UICollectionViewController class. It worked for me.

override func viewDidLoad() {

    let nib = UINib(nibName: "<WhateverYourNibName>", bundle: nil)
    self.collectionView.registerNib(nib, forCellReuseIdentifier: "title")

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

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

This syntax:

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

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

If you pass this string to loads:

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

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

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

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

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

How to create separate AngularJS controller files?

Using the angular.module API with an array at the end will tell angular to create a new module:


// It is like saying "create a new module"
angular.module('myApp.controllers', []); // Notice the empty array at the end here

Using it without the array is actually a getter function. So to seperate your controllers, you can do:


// It is just like saying "get this module and create a controller"
angular.module('myApp.controllers').controller('Ctrlr1', ['$scope', '$http', function($scope, $http) {}]);


angular.module('myApp.controllers').controller('Ctrlr2', ['$scope', '$http', function($scope, $http) {}]);

During your javascript imports, just make sure myApp.js is after AngularJS but before any controllers / services / etc...otherwise angular won't be able to initialize your controllers.

Vue-router redirect on page not found (404)

I think you should be able to use a default route handler and redirect from there to a page outside the app, as detailed below:

const ROUTER_INSTANCE = new VueRouter({
    mode: "history",
    routes: [
        { path: "/", component: HomeComponent },
        // ... other routes ...
        // and finally the default route, when none of the above matches:
        { path: "*", component: PageNotFound }

In the above PageNotFound component definition, you can specify the actual redirect, that will take you out of the app entirely:

Vue.component("page-not-found", {
    template: "",
    created: function() {
        // Redirect outside the app using plain old javascript
        window.location.href = "/my-new-404-page.html";

You may do it either on created hook as shown above, or mounted hook also.

Please note:

  1. I have not verified the above. You need to build a production version of app, ensure that the above redirect happens. You cannot test this in vue-cli as it requires server side handling.

  2. Usually in single page apps, server sends out the same index.html along with app scripts for all route requests, especially if you have set <base href="/">. This will fail for your /404-page.html unless your server treats it as a special case and serves the static page.

Let me know if it works!

Update for Vue 3 onward:

You'll need to replace the '*' path property with '/:pathMatch(.*)*' if you're using Vue 3 as the old catch-all path of '*' is no longer supported. The route would then look something like this:

{ path: '/:pathMatch(.*)*', component: PathNotFound },

See the docs for more info on this update.

How to upsert (update or insert) in SQL Server 2005

Try to check for existence:


    INSERT INTO dbo.Employee(Col1, ..., ColN)
    VALUES(Val1, .., ValN)


    UPDATE dbo.Employee
    SET Col1 = Val1, Col2 = Val2, ...., ColN = ValN
    WHERE ID = @SomeID

You could easily wrap this into a stored procedure and just call that stored procedure from the outside (e.g. from a programming language like C# or whatever you're using).

Update: either you can just write this entire statement in one long string (doable - but not really very useful) - or you can wrap it into a stored procedure:

CREATE PROCEDURE dbo.InsertOrUpdateEmployee
       @ID INT,
       @Name VARCHAR(50),
       @ItemName VARCHAR(50),  
       @ItemCatName VARCHAR(50),
       @ItemQty DECIMAL(15,2)
       INSERT INTO dbo.Table1(ID, Name, ItemName, ItemCatName, ItemQty)
       VALUES(@ID, @Name, @ItemName, @ItemCatName, @ItemQty)
       UPDATE dbo.Table1
       SET Name = @Name,
           ItemName = @ItemName,
           ItemCatName = @ItemCatName,
           ItemQty = @ItemQty
       WHERE ID = @ID

and then just call that stored procedure from your ADO.NET code

Can I do a max(count(*)) in SQL?

create view sal as
select yr,count(*) as ct from
(select title,yr from movie m, actor a, casting c
and by yr

-----VIEW CREATED-----

select yr from sal
where ct =(select max(ct) from sal)

YR 2013

Keep placeholder text in UITextField on input in IOS

Instead of using the placeholder text, you'll want to set the actual text property of the field to MM/YYYY, set the delegate of the text field and listen for this method:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {     // update the text of the label } 

Inside that method, you can figure out what the user has typed as they type, which will allow you to update the label accordingly.

Shared-memory objects in multiprocessing

If you use an operating system that uses copy-on-write fork() semantics (like any common unix), then as long as you never alter your data structure it will be available to all child processes without taking up additional memory. You will not have to do anything special (except make absolutely sure you don't alter the object).

The most efficient thing you can do for your problem would be to pack your array into an efficient array structure (using numpy or array), place that in shared memory, wrap it with multiprocessing.Array, and pass that to your functions. This answer shows how to do that.

If you want a writeable shared object, then you will need to wrap it with some kind of synchronization or locking. multiprocessing provides two methods of doing this: one using shared memory (suitable for simple values, arrays, or ctypes) or a Manager proxy, where one process holds the memory and a manager arbitrates access to it from other processes (even over a network).

The Manager approach can be used with arbitrary Python objects, but will be slower than the equivalent using shared memory because the objects need to be serialized/deserialized and sent between processes.

There are a wealth of parallel processing libraries and approaches available in Python. multiprocessing is an excellent and well rounded library, but if you have special needs perhaps one of the other approaches may be better.

Reverse a string in Java

Just For Fun..:)

Algorithm (str,len):
  char reversedStr[] =new reversedStr[len]
  Traverse i from 0 to len/2 and then
  return reversedStr;

Time Complexity:O(n) Space Complexity :O(n)

 public class Reverse {
    static char reversedStr[];    
    public static void main(String[] args) {
    private static String reversestr(String str) {
        int strlen = str.length();
        reversedStr = new char[strlen];
        for (int i = 0; i <= strlen / 2; i++) {
            reversedStr[i] = str.charAt(strlen - 1 - i);
            reversedStr[strlen - 1 - i] = str.charAt(i);

        return new String(reversedStr);


Node.js quick file server (static files over HTTP)

You can use the NPM serve package for this, if you don't need the NodeJS stuff it is a quick and easy to use tool:

1 - Install the package on your PC:

npm install -g serve

2 - Serve your static folder with serve <path> :

d:> serve d:\StaticSite

It will show you which port your static folder is being served, just navigate to the host like:


Display QImage with QtGui

Simple, but complete example showing how to display QImage might look like this:

#include <QtGui/QApplication>
#include <QLabel>

int main(int argc, char *argv[])
    QApplication a(argc, argv);

    QImage myImage;

    QLabel myLabel;

    return a.exec();

What's the UIScrollView contentInset property for?

While jball's answer is an excellent description of content insets, it doesn't answer the question of when to use it. I'll borrow from his diagrams:

   |       | 
   |content| ?
 ? |content|
cH |content|
 ? |content| contentInset.bottom
   |content| ?

That's what you get when you do it, but the usefulness of it only shows when you scroll:

   |content| ? content is still visible
   |content| ?
 ? |content|
cH |content|
 ? |content| contentInset.bottom
   |content| ?

That top row of content will still be visible because it's still inside the frame of the scroll view. One way to think of the top offset is "how much to shift the content down the scroll view when we're scrolled all the way to the top"

To see a place where this is actually used, look at the build-in Photos app on the iphone. The Navigation bar and status bar are transparent, and the contents of the scroll view are visible underneath. That's because the scroll view's frame extends out that far. But if it wasn't for the content inset, you would never be able to have the top of the content clear that transparent navigation bar when you go all the way to the top.

Date validation with ASP.NET validator

I think the following is the easiest way to do it.

<asp:TextBox ID="DateControl" runat="server" Visible="False"></asp:TextBox>
<asp:RangeValidator ID ="rvDate" runat ="server" ControlToValidate="DateControl" ErrorMessage="Invalid Date" Type="Date" MinimumValue="01/01/1900" MaximumValue="01/01/2100" Display="Dynamic"></asp:RangeValidator>

How to split strings into text and number?

I'm always the one to bring up findall() =)

>>> strings = ['foofo21', 'bar432', 'foobar12345']
>>> [re.findall(r'(\w+?)(\d+)', s)[0] for s in strings]
[('foofo', '21'), ('bar', '432'), ('foobar', '12345')]

Note that I'm using a simpler (less to type) regex than most of the previous answers.

Which JRE am I using?

The Java system property System.getProperty(...) to consult is "". This will distinguish between "OpenJDK Runtime Environment" and "Java(TM) SE Runtime Environment". They both have the same vendor - "Oracle Corporation".

This property is also included in the output for java -version.

GROUP BY and COUNT in PostgreSQL

Using OVER() and LIMIT 1:

FROM posts 
   INNER JOIN votes ON votes.post_id = 

How to get the fields in an Object via reflection?

You can use Class#getDeclaredFields() to get all declared fields of the class. You can use Field#get() to get the value.

In short:

Object someObject = getItSomehow();
for (Field field : someObject.getClass().getDeclaredFields()) {
    field.setAccessible(true); // You might want to set modifier to public first.
    Object value = field.get(someObject); 
    if (value != null) {
        System.out.println(field.getName() + "=" + value);

To learn more about reflection, check the Sun tutorial on the subject.

That said, the fields does not necessarily all represent properties of a VO. You would rather like to determine the public methods starting with get or is and then invoke it to grab the real property values.

for (Method method : someObject.getClass().getDeclaredMethods()) {
    if (Modifier.isPublic(method.getModifiers())
        && method.getParameterTypes().length == 0
        && method.getReturnType() != void.class
        && (method.getName().startsWith("get") || method.getName().startsWith("is"))
    ) {
        Object value = method.invoke(someObject);
        if (value != null) {
            System.out.println(method.getName() + "=" + value);

That in turn said, there may be more elegant ways to solve your actual problem. If you elaborate a bit more about the functional requirement for which you think that this is the right solution, then we may be able to suggest the right solution. There are many, many tools available to massage javabeans.

How to set time to 24 hour format in Calendar

if you replace in the function SimpleDateFormat("hh") with ("HH") will format the hour in 24 hours instead of 12.

SimpleDateFormat df = new SimpleDateFormat("HH:mm");

AngularJS $watch window resize inside directive

// Following is angular 2.0 directive for window re size that adjust scroll bar for give element as per your tag

---- angular 2.0 window resize directive.
import { Directive, ElementRef} from 'angular2/core';

       selector: '[resize]',
       host: { '(window:resize)': 'onResize()' } // Window resize listener

export class AutoResize {

element: ElementRef; // Element that associated to attribute.
$window: any;
       constructor(_element: ElementRef) {

         this.element = _element;
         // Get instance of DOM window.
         this.$window = angular.element(window);



    // Adjust height of element.
    onResize() {
         $(this.element.nativeElement).css('height', (this.$window.height() - 163) + 'px');

How can I create and style a div using JavaScript?

You can just use the method below:


It is very simple, in the doc below I explain

document.write("<div class='div'>Some content inside the div (It is styled!)</div>")
.div {
  background-color: red;
  padding: 5px;
  color: #fff;
  font-family: Arial;
  cursor: pointer;

.div:hover {
  background-color: blue;
  padding: 10px;

.div:hover:before {
  content: 'Hover! ';

.div:active {
  background-color: green;
  padding: 15px;

.div:active:after {
  content: ' Active! or clicked...';
<p>Below or above well show the div</p>
<p>Try pointing hover it and clicking on it. Those are tha styles aplayed. The text and background color changes.</p>

Syntax behind sorted(key=lambda: ...)

Another usage of lambda and sorted is like the following:

Given the input array: people = [[7,0],[4,4],[7,1],[5,0],[6,1],[5,2]]

The line: people_sort = sorted(people, key = lambda x: (-x[0], x[1])) will give a people_sort list as [[7,0],[7,1],[6,1],[5,0],[5,2],[4,4]]

In this case, key=lambda x: (-x[0], x[1]) basically tells sorted to firstly sort the array based on the value of the first element of each of the instance(in descending order as the minus sign suggests), and then within the same subgroup, sort based on the second element of each of the instance(in ascending order as it is the default option).

Hope this is some useful information to you!

How to call external JavaScript function in HTML

If a <script> has a src then the text content of the element will be not be executed as JS (although it will appear in the DOM).

You need to use multiple script elements.

  1. a <script> to load the external script
  2. a <script> to hold your inline code (with the call to the function in the external script)


Imshow: extent and aspect

From plt.imshow() official guide, we know that aspect controls the aspect ratio of the axes. Well in my words, the aspect is exactly the ratio of x unit and y unit. Most of the time we want to keep it as 1 since we do not want to distort out figures unintentionally. However, there is indeed cases that we need to specify aspect a value other than 1. The questioner provided a good example that x and y axis may have different physical units. Let's assume that x is in km and y in m. Hence for a 10x10 data, the extent should be [0,10km,0,10m] = [0, 10000m, 0, 10m]. In such case, if we continue to use the default aspect=1, the quality of the figure is really bad. We can hence specify aspect = 1000 to optimize our figure. The following codes illustrate this method.

%matplotlib inline
import numpy as np
import matplotlib.pyplot as plt
plt.imshow(data, origin = 'lower',  extent = [0, 10000, 0, 10], aspect = 1000)

enter image description here

Nevertheless, I think there is an alternative that can meet the questioner's demand. We can just set the extent as [0,10,0,10] and add additional xy axis labels to denote the units. Codes as follows.

plt.imshow(data, origin = 'lower',  extent = [0, 10, 0, 10])

enter image description here

To make a correct figure, we should always bear in mind that x_max-x_min = x_res * data.shape[1] and y_max - y_min = y_res * data.shape[0], where extent = [x_min, x_max, y_min, y_max]. By default, aspect = 1, meaning that the unit pixel is square. This default behavior also works fine for x_res and y_res that have different values. Extending the previous example, let's assume that x_res is 1.5 while y_res is 1. Hence extent should equal to [0,15,0,10]. Using the default aspect, we can have rectangular color pixels, whereas the unit pixel is still square!

plt.imshow(data, origin = 'lower',  extent = [0, 15, 0, 10])
# Or we have similar x_max and y_max but different data.shape, leading to different color pixel res.
plt.imshow(data, origin = 'lower',  extent = [0, 5, 0, 5])

enter image description here enter image description here

The aspect of color pixel is x_res / y_res. setting its aspect to the aspect of unit pixel (i.e. aspect = x_res / y_res = ((x_max - x_min) / data.shape[1]) / ((y_max - y_min) / data.shape[0])) would always give square color pixel. We can change aspect = 1.5 so that x-axis unit is 1.5 times y-axis unit, leading to a square color pixel and square whole figure but rectangular pixel unit. Apparently, it is not normally accepted.

plt.imshow(data, origin = 'lower',  extent = [0, 15, 0, 10], aspect = 1.5)

enter image description here

The most undesired case is that set aspect an arbitrary value, like 1.2, which will lead to neither square unit pixels nor square color pixels.

plt.imshow(data, origin = 'lower',  extent = [0, 15, 0, 10], aspect = 1.2)

enter image description here

Long story short, it is always enough to set the correct extent and let the matplotlib do the remaining things for us (even though x_res!=y_res)! Change aspect only when it is a must.

Keyboard shortcut to paste clipboard content into command prompt window (Win XP)

This is not really a shortcut but just a quick access to the control menu: Alt-space E P

If you can use your mouse, right click on the cmd window works as paste when I tried it.

What's the simplest way to print a Java array?

There are several ways to print an array elements.First of all, I'll explain that, what is an array?..Array is a simple data structure for storing data..When you define an array , Allocate set of ancillary memory blocks in RAM.Those memory blocks are taken one unit ..

Ok, I'll create an array like this,

class demo{
      public static void main(String a[]){

           int[] number={1,2,3,4,5};


Now look at the output,

enter image description here

You can see an unknown string printed..As I mentioned before, the memory address whose array(number array) declared is printed.If you want to display elements in the array, you can use "for loop " , like this..

class demo{
      public static void main(String a[]){

           int[] number={1,2,3,4,5};

           int i;

                 System.out.print(number[i]+"  ");

Now look at the output,

enter image description here

Ok,Successfully printed elements of one dimension array..Now I am going to consider two dimension array..I'll declare two dimension array as "number2" and print the elements using "Arrays.deepToString()" keyword.Before using that You will have to import 'java.util.Arrays' library.

 import java.util.Arrays;

 class demo{
      public static void main(String a[]){

           int[][] number2={{1,2},{3,4},{5,6}};`


consider the output,

enter image description here

At the same time , Using two for loops ,2D elements can be printed..Thank you !

How to add a downloaded .box file to Vagrant?

Solution for Windows:

  • Open the cmd or powershell as admin
  • CD into the folder containing the .box file
  • vagrant box add --name name_of_my_box ''
  • vagrant box list should show the new box in the list

Solution for MAC:

  • Open terminal
  • CD into the folder containing the .box file
  • vagrant box add --name name_of_my_box "./"
  • vagrant box list should show the new box in the list

Iteration ng-repeat only X times in AngularJs

This is the simplest workaround I could think of.

<span ng-repeat="n in [].constructor(5) track by $index">

Here's a Plunker example.

Simple Java Client/Server Program

Instead of using the IP address from, what if you just get the IP address directly from the machine and plug that in? will give you the address of your router (I'm assuming you're on a home network). I don't think port forwarding will work since your request will come from within the network, not outside.

Does a foreign key automatically create an index?

No, there is no implicit index on foreign key fields, otherwise why would Microsoft say "Creating an index on a foreign key is often useful". Your colleague may be confusing the foreign key field in the referring table with the primary key in the referred-to table - primary keys do create an implicit index.

How to check if command line tools is installed

To check if command line tools are installed run:

xcode-select --version

// if installed you will see the below with the version found in your system
// xcode-select version 1234.

If command line tools are not installed run:

xcode-select --install

How to assert two list contain the same elements in Python?


l1 = [a,b]
l2 = [b,a]

In Python >= 3.0

assertCountEqual(l1, l2) # True

In Python >= 2.7, the above function was named:

assertItemsEqual(l1, l2) # True

In Python < 2.7

import unittest2
assertItemsEqual(l1, l2) # True

Via six module (Any Python version)

import unittest
import six
class MyTest(unittest.TestCase):
    def test(self):
        six.assertCountEqual(self, self.l1, self.l2) # True

How can I run PowerShell with the .NET 4 runtime?

The best solution I have found is in the blog post Using Newer Version(s) of .NET with PowerShell. This allows powershell.exe to run with .NET 4 assemblies.

Simply modify (or create) $pshome\powershell.exe.config so that it contains the following:

<?xml version="1.0"?> 
    <startup useLegacyV2RuntimeActivationPolicy="true"> 
        <supportedRuntime version="v4.0.30319"/> 
        <supportedRuntime version="v2.0.50727"/> 

Additional, quick setup notes:

Locations and files are somewhat platform dependent; however will give you an inline gist of how to make the solution work for you.

  • You can find PowerShell's location on your computer by executing cd $pshome in the Powershell window (doesn't work from DOS prompt).
    • Path will be something like (example) C:\Windows\System32\WindowsPowerShell\v1.0\
  • The filename to put configuration in is: powershell.exe.config if your PowerShell.exe is being executed (create the config file if need be).
    • If PowerShellISE.Exe is running then you need to create its companion config file as PowerShellISE.Exe.config

REST API Authentication

You can use HTTP Basic or Digest Authentication. You can securely authenticate users using SSL on the top of it, however, it slows down the API a little bit.

  • Basic authentication - uses Base64 encoding on username and password
  • Digest authentication - hashes the username and password before sending them over the network.

OAuth is the best it can get. The advantages oAuth gives is a revokable or expirable token. Refer following on how to implement: Working Link from comments:

how to check confirm password field in form without reloading page

$box = $('input[name=showPassword]');

    if ($(this).is(':checked')) {
        $('input[name=pswd]').attr('type', 'password');    
    } else {
        $('input[name=pswd]').attr('type', 'text');

Full examples of using pySerial package


import serial, time
#initialization and open the port

#possible timeout values:
#    1. None: wait forever, block call
#    2. 0: non-blocking mode, return immediately
#    3. x, x is bigger than 0, float allowed, timeout block call

ser = serial.Serial()
#ser.port = "/dev/ttyUSB0"
ser.port = "/dev/ttyUSB7"
#ser.port = "/dev/ttyS2"
ser.baudrate = 9600
ser.bytesize = serial.EIGHTBITS #number of bits per bytes
ser.parity = serial.PARITY_NONE #set parity check: no parity
ser.stopbits = serial.STOPBITS_ONE #number of stop bits
#ser.timeout = None          #block read
ser.timeout = 1            #non-block read
#ser.timeout = 2              #timeout block read
ser.xonxoff = False     #disable software flow control
ser.rtscts = False     #disable hardware (RTS/CTS) flow control
ser.dsrdtr = False       #disable hardware (DSR/DTR) flow control
ser.writeTimeout = 2     #timeout for write

except Exception, e:
    print "error open serial port: " + str(e)

if ser.isOpen():

        ser.flushInput() #flush input buffer, discarding all its contents
        ser.flushOutput()#flush output buffer, aborting current output 
                 #and discard all that is in buffer

        #write data
        print("write data: AT+CSQ")

       time.sleep(0.5)  #give the serial port sometime to receive the data

       numOfLines = 0

       while True:
          response = ser.readline()
          print("read data: " + response)

        numOfLines = numOfLines + 1

        if (numOfLines >= 5):

    except Exception, e1:
        print "error communicating...: " + str(e1)

    print "cannot open serial port "

How do I use CMake?

Cmake from Windows terminal:

mkdir build
cd build/
cmake ..
cmake --build . --config Release

Enable remote connections for SQL Server Express 2012

I had to add port via Configuration Manager and add the port number in my sql connection [host]\[db instance name],1433

Note the , (comma) between instancename and port

Could not connect to SMTP host:, port: 465, response: -1

Port 465 is for "smtp over SSL".

[...] For example, use
    props.put("mail.smtp.port", "888");
to set the mail.smtp.port property, which is of type int.

Note that if you're using the "smtps" protocol to access SMTP over SSL, 
all the properties would be named "mail.smtps.*"

Could not load file or assembly '***.dll' or one of its dependencies

I had the same issue - a .dll working all the time, then my computer crashed and afterwards I had this problem of 'could not load file or assembly ....dll'

Two possible solutions: when the computer crashed there may be some inconsistent files in

C:\Users\<yourUserName>\AppData\Local\Temp\Temporary ASP.NET Files

Deleting that folder, recompiling and the error was gone.

Once I had also to delete my packages folder (I had read that somewhere else). Allow Visual Studio / nuget to install missing packages (or manually reinstall) and afterwards everything was fine again.

Testing if a list of integer is odd or even

Just use the modulus

loop through the list and run the following on each item

if(num % 2 == 0)
  //is even
  //is odd

Alternatively if you want to know if all are even you can do something like this:

bool allAreEven = lst.All(x => x % 2 == 0);

How to clear browser cache with php?

It seams you need to versionate, so when some change happens browser will catch something new and user won't need to clear browser's cache.

You can do it by subfolders (example /css/v1/style.css) or by filename (example: css/style_v1.css) or even by setting different folders for your website, example:

And use a .htaccess or even change httpd.conf to redirect to your current application.

If's about one image or page:

    <?$time = date("H:i:s");?>
    <img src="myfile.jpg?time=<?$time;?>">

You can use $time on parts when you don't wanna cache. So it will always pull a new image. Versionate it seams a better approach, otherwise it can overload your server. Remember, browser's cache it's not only good to user experience, but also for your server.

How to justify navbar-nav in Bootstrap 3

I know this is an old post but I would like share my solution. I spent several hours trying to make a justified navigation menu. You do not really need to modify anything in bootstrap css. Just need to add the correct class in the html.

   <nav class="nav navbar-default navbar-fixed-top">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#collapsable-1" aria-expanded="false">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            <a class="navbar-brand" href="#top">Brand Name</a>
        <div class="collapse navbar-collapse" id="collapsable-1">
            <ul class="nav nav-justified">
                <li><a href="#about-me">About Me</a></li>
                <li><a href="#skills">Skills</a></li>
                <li><a href="#projects">Projects</a></li>
                <li><a href="#contact-me">Contact Me</a></li>

This CSS code will simply remove the navbar-brand class when the screen reaches 768px.

media@(min-width: 768px){
        display: none;

How do I check which version of NumPy I'm using?

>> import numpy
>> print numpy.__version__

Purpose of installing Twitter Bootstrap through npm?

Answer 1:

  • Downloading bootstrap through npm (or bower) permits you to gain some latency time. Instead of getting a remote resource, you get a local one, it's quicker, except if you use a cdn (check below answer)

  • "npm" was originally to get Node Module, but with the essort of the Javascript language (and the advent of browserify), it has a bit grown up. In fact, you can even download AngularJS on npm, that is not a server side framework. Browserify permits you to use AMD/RequireJS/CommonJS on client side so node modules can be used on client side.

Answer 2:

If you npm install bootstrap (if you dont use a particular grunt or gulp file to move to a dist folder), your bootstrap will be located in "./node_modules/bootstrap/bootstrap.min.css" if I m not wrong.

Create list of single item repeated N times

As others have pointed out, using the * operator for a mutable object duplicates references, so if you change one you change them all. If you want to create independent instances of a mutable object, your xrange syntax is the most Pythonic way to do this. If you are bothered by having a named variable that is never used, you can use the anonymous underscore variable.

[e for _ in xrange(n)]

How to initialize a private static const map in C++?

If you find boost::assign::map_list_of useful, but can't use it for some reason, you could write your own:

template<class K, class V>
struct map_list_of_type {
  typedef std::map<K, V> Map;
  Map data;
  map_list_of_type(K k, V v) { data[k] = v; }
  map_list_of_type& operator()(K k, V v) { data[k] = v; return *this; }
  operator Map const&() const { return data; }
template<class K, class V>
map_list_of_type<K, V> my_map_list_of(K k, V v) {
  return map_list_of_type<K, V>(k, v);

int main() {
  std::map<int, char> example = 
    my_map_list_of(1, 'a') (2, 'b') (3, 'c');
  cout << example << '\n';

It's useful to know how such things work, especially when they're so short, but in this case I'd use a function:


struct A {
  static map<int, int> const m;


namespace {
map<int,int> create_map() {
  map<int, int> m;
  m[1] = 2; // etc.
  return m;

map<int, int> const A::m = create_map();

XDocument or XmlDocument

I believe that XDocument makes a lot more object creation calls. I suspect that for when you're handling a lot of XML documents, XMLDocument will be faster.

One place this happens is in managing scan data. Many scan tools output their data in XML (for obvious reasons). If you have to process a lot of these scan files, I think you'll have better performance with XMLDocument.

How to retrieve form values from HTTPPOST, dictionary or?

You could have your controller action take an object which would reflect the form input names and the default model binder will automatically create this object for you:

public ActionResult SubmitAction(SomeModel model)
    var value1 = model.SimpleProp1;
    var value2 = model.SimpleProp2;
    var value3 = model.ComplexProp1.SimpleProp1;

    ... return something ...

Another (obviously uglier) way is:

public ActionResult SubmitAction()
    var value1 = Request["SimpleProp1"];
    var value2 = Request["SimpleProp2"];
    var value3 = Request["ComplexProp1.SimpleProp1"];

    ... return something ...

How to set up default schema name in JPA configuration?

Use this

@Table (name = "Test", schema = "\"schema\"")

insteade of @Table (name = "Test", schema = "schema")

If you are on postgresql the request is :

SELECT * FROM "schema".test 

not :

SELECT * FROM schema.test

PS: Test is a table

Using find command in bash script

If you want to loop over what you "find", you should use this:

find . -type f -name '*.*' -print0 | while IFS= read -r -d '' file; do
    printf '%s\n' "$file"


Float a div above page content


position: absolute;
top: ...px;
left: ...px;

To position the div. Make sure it doesn't have a parent tag with position: relative;

For Restful API, can GET method use json data?

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

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

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

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

How to include a child object's child object in Entity Framework 5

If you include the library System.Data.Entity you can use an overload of the Include() method which takes a lambda expression instead of a string. You can then Select() over children with Linq expressions rather than string paths.

return DatabaseContext.Applications
     .Include(a => a.Children.Select(c => c.ChildRelationshipType));

How to send 100,000 emails weekly?

Short answer: While it's technically possible to send 100k e-mails each week yourself, the simplest, easiest and cheapest solution is to outsource this to one of the companies that specialize in it (I did say "cheapest": there's no limit to the amount of development time (and therefore money) that you can sink into this when trying to DIY).

Long answer: If you decide that you absolutely want to do this yourself, prepare for a world of hurt (after all, this is e-mail/e-fail we're talking about). You'll need:

  • e-mail content that is not spam (otherwise you'll run into additional major roadblocks on every step, even legal repercussions)
  • in addition, your content should be easy to distinguish from spam - that may be a bit hard to do in some cases (I heard that a certain pharmaceutical company had to all but abandon e-mail, as their brand names are quite common in spams)
  • a configurable SMTP server of your own, one which won't buckle when you dump 100k e-mails onto it (your ISP's upstream server won't be sufficient here and you'll make the ISP violently unhappy; we used two dedicated boxes)
  • some mail wrapper (e.g. PhpMailer if PHP's your poison of choice; using PHP's mail() is horrible enough by itself)
  • your own sender function to run in a loop, create the mails and pass them to the wrapper (note that you may run into PHP's memory limits if your app has a memory leak; you may need to recycle the sending process periodically, or even better, decouple the "creating e-mails" and "sending e-mails" altogether)

Surprisingly, that was the easy part. The hard part is actually sending it:

  • some servers will ban you when you send too many mails close together, so you need to shuffle and watch your queue (e.g. send one mail to [email protected], then three to other domains, only then another to [email protected])
  • you need to have correct PTR, SPF, DKIM records
  • handling remote server timeouts, misconfigured DNS records and other network pleasantries
  • handling invalid e-mails (and no, regex is the wrong tool for that)
  • handling unsubscriptions (many legitimate newsletters have been reclassified as spam due to many frustrated users who couldn't unsubscribe in one step and instead chose to "mark as spam" - the spam filters do learn, esp. with large e-mail providers)
  • handling bounces and rejects ("no such mailbox [email protected]","mailbox [email protected] full")
  • handling blacklisting and removal from blacklists (Sure, you're not sending spam. Some recipients won't be so sure - with such large list, it will happen sometimes, no matter what precautions you take. Some people (e.g. your not-so-scrupulous competitors) might even go as far to falsely report your mailings as spam - it does happen. On average, it takes weeks to get yourself removed from a blacklist.)

And to top it off, you'll have to manage the legal part of it (various federal, state, and local laws; and even different tangles of laws once you send outside the U.S. (note: you have no way of finding if [email protected] lives in Southwest Elbonia, the country with world's most draconian antispam laws)).

I'm pretty sure I missed a few heads of this hydra - are you still sure you want to do this yourself? If so, there'll be another wave, this time merely the annoying problems inherent in sending an e-mail. (You see, SMTP is a store-and-forward protocol, which means that your e-mail will be shuffled across many SMTP servers around the Internet, in the hope that the next one is a bit closer to the final recipient. Basically, the e-mail is sent to an SMTP server, which puts it into its forward queue; when time comes, it will forward it further to a different SMTP server, until it reaches the SMTP server for the given domain. This forward could happen immediately, or in a few minutes, or hours, or days, or never.) Thus, you'll see the following issues - most of which could happen en route as well as at the destination:

  • the remote SMTP servers don't want to talk to your SMTP server
  • your mails are getting marked as spam (<blink> is not your friend here, nor is <font color=...>)
  • your mails are delivered days, even weeks late (contrary to popular opinion, SMTP is designed to make a best effort to deliver the message sometime in the future - not to deliver it now)
  • your mails are not delivered at all (already sent from e-mail server on hop #4, not sent yet from server on hop #5, the server that currently holds the message crashes, data is lost)
  • your mails are mangled by some braindead server en route (this one is somewhat solvable with base64 encoding, but then the size goes up and the e-mail looks more suspicious)
  • your mails are delivered and the recipients seem not to want them ("I'm sure I didn't sign up for this, I remember exactly what I did a year ago" (of course you do, sir))
  • users with various versions of Microsoft Outlook and its special handling of Internet mail
  • wizard's apprentice mode (a self-reinforcing positive feedback loop - in other words, automated e-mails as replies to automated e-mails as replies to...; you really don't want to be the one to set this off, as you'd anger half the internet at yourself)

and it'll be your job to troubleshoot and solve this (hint: you can't, mostly). The people who run a legit mass-mailing businesses know that in the end you can't solve it, and that they can't solve it either - and they have the reasons well researched, documented and outlined (maybe even as a Powerpoint presentation - complete with sounds and cool transitions - that your bosses can understand), as they've had to explain this a million times before. Plus, for the problems that are actually solvable, they know very well how to solve them.

If, after all this, you are not discouraged and still want to do this, go right ahead: it's even possible that you'll find a better way to do this. Just know that the road ahead won't be easy - sending e-mail is trivial, getting it delivered is hard.

How to recover the deleted files using "rm -R" command in linux server?

Short answer: You can't. rm removes files blindly, with no concept of 'trash'.

Some Unix and Linux systems try to limit its destructive ability by aliasing it to rm -i by default, but not all do.

Long answer: Depending on your filesystem, disk activity, and how long ago the deletion occured, you may be able to recover some or all of what you deleted. If you're using an EXT3 or EXT4 formatted drive, you can check out extundelete.

In the future, use rm with caution. Either create a del alias that provides interactivity, or use a file manager.

Android - Launcher Icon Size

You can create icons directly in the android studio itself.The Steps you need to follow are:

1.Right click on Res->New->Image asset

2.CHange asset type to image.

3.Load the image from the local disk

4.You have options to trim,change padding and add background also.Change the values if you need. Next->Finish.

The image wil be automatically added to mipmap-mdpi,mipmap-hdpi,mipmap-xhdpi,mipmap-xxhdpi,mipmap-xxxhdpi if you select launcher icon or drawable-mdpi,drawable-hdpi,drawable-xhdpi,drawable-xxhdpi,drawable-xxxhdpi ifyou select other icon optins.

Append text to file from command line without using io redirection

If you don't mind using sed then,

$ cat test 
this is line 1
$ sed -i '$ a\this is line 2 without redirection' test 
$ cat test 
this is line 1
this is line 2 without redirection

As the documentation may be a bit long to go through, some explanations :

  • -i means an inplace transformation, so all changes will occur in the file you specify
  • $ is used to specify the last line
  • a means append a line after
  • \ is simply used as a delimiter

Switch php versions on commandline ubuntu 16.04

Interactive switching mode

sudo update-alternatives --config php
sudo update-alternatives --config phar
sudo update-alternatives --config phar.phar

Manual Switching

From PHP 5.6 => PHP 7.1

Default PHP 5.6 is set on your system and you need to switch to PHP 7.1.


$ sudo a2dismod php5.6
$ sudo a2enmod php7.1
$ sudo service apache2 restart

Command Line:

$ sudo update-alternatives --set php /usr/bin/php7.1
$ sudo update-alternatives --set phar /usr/bin/phar7.1
$ sudo update-alternatives --set phar.phar /usr/bin/phar.phar7.1

From PHP 7.1 => PHP 5.6

Default PHP 7.1 is set on your system and you need to switch to PHP 5.6.


$ sudo a2dismod php7.1
$ sudo a2enmod php5.6
$ sudo service apache2 restart

Command Line:

$ sudo update-alternatives --set php /usr/bin/php5.6


iPhone - Grand Central Dispatch main thread

One place where it's useful is for UI activities, like setting a spinner before a lengthy operation:

- (void) handleDoSomethingButton{

    [mySpinner startAnimating];

    (do something lengthy)
    [mySpinner stopAnimating];

will not work, because you are blocking the main thread during your lengthy thing and not letting UIKit actually start the spinner.

- (void) handleDoSomethingButton{
     [mySpinner startAnimating];

     dispatch_async (dispatch_get_main_queue(), ^{
          (do something lengthy)
          [mySpinner stopAnimating];

will return control to the run loop, which will schedule UI updating, starting the spinner, then will get the next thing off the dispatch queue, which is your actual processing. When your processing is done, the animation stop is called, and you return to the run loop, where the UI then gets updated with the stop.

How to Set focus to first text input in a bootstrap modal after shown

if you're looking for a snippet that would work for all your modals, and search automatically for the 1st input text in the opened one, you should use this:

$('.modal').on('', function () {
    $(this).find( 'input:visible:first').focus();

If your modal is loaded using ajax, use this instead:

$(document).on('', '.modal', function() {

Returning a promise in an async function in TypeScript

When you do new Promise((resolve)... the type inferred was Promise<{}> because you should have used new Promise<number>((resolve).

It is interesting that this issue was only highlighted when the async keyword was added. I would recommend reporting this issue to the TS team on GitHub.

There are many ways you can get around this issue. All the following functions have the same behavior:

const whatever1 = () => {
    return new Promise<number>((resolve) => {

const whatever2 = async () => {
    return new Promise<number>((resolve) => {

const whatever3 = async () => {
    return await new Promise<number>((resolve) => {

const whatever4 = async () => {
    return Promise.resolve(4);

const whatever5 = async () => {
    return await Promise.resolve(4);

const whatever6 = async () => Promise.resolve(4);

const whatever7 = async () => await Promise.resolve(4);

In your IDE you will be able to see that the inferred type for all these functions is () => Promise<number>.

Center form submit buttons HTML / CSS

Try this :

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
    <style type="text/css">

        #btn_i {
        #formbox {
            margin:auto 0;
            text-align: center;
    <form method="post" action="">
        <div id="formbox">
            <input value="Search" title="Search" type="submit" id="btn_s"> 
            <input value="I'm Feeling Lucky" title="I'm Feeling Lucky" name="lucky" type="submit" id="btn_i">

This has 2 examples, you can use the one that fits best in your situation.

  • use text-align:center on the parent container, or create a container for this.
  • if the container has to have a fixed size, use auto left and right margins to center it in the parent container.

note that auto is used with single blocks to center them in the parent space by distrubuting the empty space to the left and right.

How do you concatenate Lists in C#?

targetList = list1.Concat(list2).ToList();

It's working fine I think so. As previously said, Concat returns a new sequence and while converting the result to List, it does the job perfectly.

Onchange open URL via select - jQuery

If you don't want the url to put it on option's value, i'll give u example :

<select class="abc">
    <option value="0" href="hello">Hell</option>
    <option value="1" href="dello">Dell</option>
    <option value="2" href="cello">Cell</option>


How to Programmatically Add Views to Views

This is late but this may help someone :) :) For adding the view programmatically try like

LinearLayout rlmain = new LinearLayout(this);      
LinearLayout.LayoutParams llp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.FILL_PARENT);          
LinearLayout   ll1 = new LinearLayout (this);

ImageView iv = new ImageView(this);
LinearLayout .LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);

setContentView(rlmain, llp);

This will create your entire view programmatcally. You can add any number of view as same. Hope this may help. :)

How to kill zombie process

I tried:

ps aux | grep -w Z   # returns the zombies pid
ps o ppid {returned pid from previous command}   # returns the parent
kill -1 {the parent id from previous command}

this will work :)

How to make a countdown timer in Android?

public class Scan extends AppCompatActivity {
int minute;
long min;
TextView tv_timer;
protected void onCreate(Bundle savedInstanceState) {
    minute=Integer.parseInt("Your time in string form like 10");
    min= minute*60*1000;
private void counter(long min) {
    CountDownTimer timer = new CountDownTimer(min, 1000) {
        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000) % 60;
            int minutes = (int) ((millisUntilFinished / (1000 * 60)) % 60);
            int hours = (int) ((millisUntilFinished / (1000 * 60 * 60)) % 24);
            tv_timer.setText(String.format("%d:%d:%d", hours, minutes, seconds));
        public void onFinish() {
            Toast.makeText(getApplicationContext(), "Your time has been completed",


Access Enum value using EL with JSTL

When using a MVC framework I put the following in my controller.


This allows me to use the following in my JSP Page.

<script> var url = '${INBOX_ACTION}=' + someValue;</script>

It can also be used in your comparison

<c:when test="${someModel.action == INBOX_ACTION}">

Which I prefer over putting in a string literal.

String to date in Oracle with milliseconds

Oracle stores only the fractions up to second in a DATE field.

Use TIMESTAMP instead:

SELECT  TO_TIMESTAMP('2004-09-30 23:53:48,140000000', 'YYYY-MM-DD HH24:MI:SS,FF9')
FROM    dual

, possibly casting it to a DATE then:

SELECT  CAST(TO_TIMESTAMP('2004-09-30 23:53:48,140000000', 'YYYY-MM-DD HH24:MI:SS,FF9') AS DATE)
FROM    dual

jquery get all input from specific form

        $form = $(this);
        $i = 0;
        $("form input[required],form select[required]").each(function(){
            if ($(this).val().trim() == ''){
                $(this).css('border-color', 'red');
                $(this).css('border-color', '');    
        if($i != 0) e.preventDefault();
        if ($(this).val().trim() == '')
            $(this).css('border-color', 'red');
            $(this).css('border-color', '');    
        if ($(this).val().trim() == '')
            $(this).css('border-color', 'red');
            $(this).css('border-color', '');

How to convert column with string type to int form in pyspark data frame?

Another way to do it is using the StructField if you have multiple fields that needs to be modified.


from pyspark.sql.types import StructField,IntegerType, StructType,StringType



 |-- CLICK_FLG: string (nullable = true)
 |-- OPEN_FLG: string (nullable = true)
 |-- I1_GNDR_CODE: string (nullable = true)
 |-- TRW_INCOME_CD_V4: string (nullable = true)
 |-- ASIAN_CD: integer (nullable = true)
 |-- I1_INDIV_HHLD_STATUS_CODE: string (nullable = true)


 |-- CLICK_FLG: integer (nullable = true)
 |-- OPEN_FLG: integer (nullable = true)
 |-- I1_GNDR_CODE: string (nullable = true)
 |-- TRW_INCOME_CD_V4: string (nullable = true)
 |-- ASIAN_CD: integer (nullable = true)
 |-- I1_INDIV_HHLD_STATUS_CODE: integer (nullable = true)

This is slightly a long procedure to cast , but the advantage is that all the required fields can be done.

It is to be noted that if only the required fields are assigned the data type, then the resultant dataframe will contain only those fields which are changed.

How to get child element by ID in JavaScript?

(Dwell in atom)

<div id="note">

   <textarea id="textid" class="textclass">Text</textarea>


<script type="text/javascript">

   var note = document.getElementById('textid').value;



What does 'Unsupported major.minor version 52.0' mean, and how do I fix it?

Your code was compiled with Java 8.

Either compile your code with an older JDK (compliance level) or run it on a Java 8 JRE.

Hope this helps...

Eclipse: All my projects disappeared from Project Explorer

All of my projects were closed and I had hid the closed projects in the settings. So to open projects go to top right view menu, and uncheck Closed Projects option. Assuming it is checked already.

enter image description here

Move column by name to front of table in pandas


seems to be a pretty easy way about this.

How to check if AlarmManager already has an alarm set?

Just found another solution, it seems to work for me

Intent myIntent = new Intent(MainActivity.this, MyReceiver.class);

boolean isWorking = (PendingIntent.getBroadcast(MainActivity.this, 0, myIntent, PendingIntent.FLAG_NO_CREATE) != null);
if (isWorking) {Log.d("alarm", "is working");} else {Log.d("alarm", "is not working");}

if(!isWorking) {
    pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, myIntent,    PendingIntent.FLAG_UPDATE_CURRENT);
    alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
    int timeNotif = 5 * 60 * 1000;//time in ms, 7*24*60*60*1000 for 1 week
    Log.d("Notif", "Notification every (ms): " + timeNotif);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), timeNotif, pendingIntent);

How to set the title text color of UIButton?

Example in setting button title color

btnDone.setTitleColor(.black, for: .normal)

Selenium: Can I set any of the attribute value of a WebElement in Selenium?

I have created this jquery that solved my problem.

public void ChangeClassIntoSelected(String name,String div) {
        JavascriptExecutor js = (JavascriptExecutor) driver;
        js.executeScript("Array.from($(\"div." + div +" ul[name=" + name + "]\")[0].children).forEach((element, index) => {\n" +
                "   $(element).addClass('ui-selected');\n" +

With this script you are able to change the actual class name into some other thing.

ADB Shell Input Events

By adb shell input keyevent, either an event_code or a string will be sent to the device.

usage: input [text|keyevent]
  input text <string>
  input keyevent <event_code>

Some possible values for event_code are:

1 -->  "KEYCODE_MENU" 
3 -->  "KEYCODE_HOME" 
4 -->  "KEYCODE_BACK" 
5 -->  "KEYCODE_CALL" 
7 -->  "KEYCODE_0" 
8 -->  "KEYCODE_1" 
9 -->  "KEYCODE_2" 
10 -->  "KEYCODE_3" 
11 -->  "KEYCODE_4" 
12 -->  "KEYCODE_5" 
13 -->  "KEYCODE_6" 
14 -->  "KEYCODE_7" 
15 -->  "KEYCODE_8" 
16 -->  "KEYCODE_9" 
17 -->  "KEYCODE_STAR" 
18 -->  "KEYCODE_POUND" 
19 -->  "KEYCODE_DPAD_UP" 
26 -->  "KEYCODE_POWER" 
28 -->  "KEYCODE_CLEAR" 
29 -->  "KEYCODE_A" 
30 -->  "KEYCODE_B" 
31 -->  "KEYCODE_C" 
32 -->  "KEYCODE_D" 
33 -->  "KEYCODE_E" 
34 -->  "KEYCODE_F" 
35 -->  "KEYCODE_G" 
36 -->  "KEYCODE_H" 
37 -->  "KEYCODE_I" 
38 -->  "KEYCODE_J" 
39 -->  "KEYCODE_K" 
40 -->  "KEYCODE_L" 
41 -->  "KEYCODE_M" 
42 -->  "KEYCODE_N" 
43 -->  "KEYCODE_O" 
44 -->  "KEYCODE_P" 
45 -->  "KEYCODE_Q" 
46 -->  "KEYCODE_R" 
47 -->  "KEYCODE_S" 
48 -->  "KEYCODE_T" 
49 -->  "KEYCODE_U" 
50 -->  "KEYCODE_V" 
51 -->  "KEYCODE_W" 
52 -->  "KEYCODE_X" 
53 -->  "KEYCODE_Y" 
54 -->  "KEYCODE_Z" 
55 -->  "KEYCODE_COMMA" 
61 -->  "KEYCODE_TAB" 
62 -->  "KEYCODE_SPACE" 
63 -->  "KEYCODE_SYM" 
66 -->  "KEYCODE_ENTER" 
67 -->  "KEYCODE_DEL" 
68 -->  "KEYCODE_GRAVE" 
69 -->  "KEYCODE_MINUS" 
76 -->  "KEYCODE_SLASH" 
77 -->  "KEYCODE_AT" 
78 -->  "KEYCODE_NUM" 
80 -->  "KEYCODE_FOCUS" 
81 -->  "KEYCODE_PLUS" 
82 -->  "KEYCODE_MENU" 

The sendevent utility sends touch or keyboard events, as well as other events for simulating the hardware events. Refer to this article for details: Android, low level shell click on screen.

The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception

You need the oracle client driver installed for those classes to work.

There might be 3rd party connection frameworks out there that can handle Oracle, perhaps someone else might know of some specific ones.

What is getattr() exactly and how do I use it?

Another use of getattr() in implementing a switch statement in Python. It uses both reflection to get the case type.

import sys

class SwitchStatement(object):
    """ a class to implement switch statement and a way to show how to use gettattr in Pythion"""

    def case_1(self):
        return "value for case_1"

    def case_2(self):
        return "value for case_2"

    def case_3(self):
        return "value for case_3"

    def case_4(self):
        return "value for case_4"

    def case_value(self, case_type=1):
        """This is the main dispatchmethod, that uses gettattr"""
        case_method = 'case_' + str(case_type)
        # fetch the relevant method name
        # Get the method from 'self'. Default to a lambda.
        method = getattr(self, case_method, lambda: "Invalid case type")
        # Call the method as we return it
        return method()

def main(_):
    switch = SwitchStatement()
    print swtich.case_value(_)

if __name__ == '__main__':

MongoDB Show all contents from all collections

var collections = db.getCollectionNames();
for(var i = 0; i< collections.length; i++){    
   print('Collection: ' + collections[i]); // print the name of each collection
   db.getCollection(collections[i]).find().forEach(printjson); //and then print the json of each of its elements

I think this script might get what you want. It prints the name of each collection and then prints its elements in json.

Copy-item Files in Folders and subfolders in the same directory structure of source server using PowerShell

one time i found this script, this copy folder and files and keep the same structure of the source in the destination, you can make some tries with this.

# Find the source files

# Set the target file
Get-ChildItem $sourceDir -Include *.* -Recurse |  foreach {

    # Remove the original  root folder
    $split = $_.Fullname  -split '\\'
    $DestFile =  $split[1..($split.Length - 1)] -join '\' 

    # Build the new  destination file path
    $DestFile = $targetDir+$DestFile

    # Move-Item won't  create the folder structure so we have to 
    # create a blank file  and then overwrite it
    $null = New-Item -Path  $DestFile -Type File -Force
    Move-Item -Path  $_.FullName -Destination $DestFile -Force

Max size of URL parameters in _GET

Ok, it seems that some versions of PHP have a limitation of length of GET params:

Please note that PHP setups with the suhosin patch installed will have a default limit of 512 characters for get parameters. Although bad practice, most browsers (including IE) supports URLs up to around 2000 characters, while Apache has a default of 8000.

To add support for long parameters with suhosin, add suhosin.get.max_value_length = <limit> in php.ini


How to maintain aspect ratio using HTML IMG tag

None of the methods listed scale the image to the largest possible size that fits in a box while retaining the desired aspect ratio.

This cannot be done with the IMG tag (at least not without a bit of JavaScript), but it can be done as follows:

 <div style="background:center no-repeat url(...);background-size:contain;width:...;height:..."></div>

Module AppRegistry is not registered callable module (calling runApplication)

I am using Expo

In my case, I resolved the issue by adding the following code in app.json file

  "android": {
    "package": "com.mycompanyname.myappname

SQL Server database backup restore on lower version

Go to Task->Generate Scripts...

In Advanced in "Types of data for script" select "Schema and data" and try to run this script in your lower version.

CSS scale height to match width - possibly with a formfactor

#map { 
    width: 100%; 
    height: 100vw * 1.72 

How to get a variable from a file to another file in Node.js

You need module.exports:


An object which is shared between all instances of the current module and made accessible through require(). exports is the same as the module.exports object. See src/node.js for more information. exports isn't actually a global but rather local to each module.

For example, if you would like to expose variableName with value "variableValue" on sourceFile.js then you can either set the entire exports as such:

module.exports = { variableName: "variableValue" };

Or you can set the individual value with:

module.exports.variableName = "variableValue";

To consume that value in another file, you need to require(...) it first (with relative pathing):

const sourceFile = require('./sourceFile');

Alternatively, you can deconstruct it.

const { variableName } = require('./sourceFile');
//            current directory --^
// ../     would be one directory down
// ../../  is two directories down

If all you want out of the file is variableName then


const variableName = 'variableValue'
module.exports = variableName


const variableName = require('./sourceFile')

Edit (2020):

Since Node.js version 8.9.0, you can also use ECMAScript Modules with varying levels of support. The documentation.

  • For Node v13.9.0 and beyond, experimental modules are enabled by default
  • For versions of Node less than version 13.9.0, use --experimental-modules

Node.js will treat the following as ES modules when passed to node as the initial input, or when referenced by import statements within ES module code:

  • Files ending in .mjs.
  • Files ending in .js when the nearest parent package.json file contains a top-level field "type" with a value of "module".
  • Strings passed in as an argument to --eval or --print, or piped to node via STDIN, with the flag --input-type=module.

Once you have it setup, you can use import and export.

Using the example above, there are two approaches you can take


// This is a named export of variableName
export const variableName = 'variableValue'
// Alternatively, you could have exported it as a default. 
// For sake of explanation, I'm wrapping the variable in an object
// but it is not necessary. 
// You can actually omit declaring what variableName is here. 
// { variableName } is equivalent to { variableName: variableName } in this case. 
export default { variableName: variableName } 


// There are three ways of importing. 
// If you need access to a non-default export, then 
// you use { nameOfExportedVariable } 
import { variableName } from './sourceFile'
console.log(variableName) // 'variableValue'

// Otherwise, you simply provide a local variable name 
// for what was exported as default.
import sourceFile from './sourceFile'
console.log(sourceFile.variableName) // 'variableValue'


// The third way of importing is for situations where there
// isn't a default export but you want to warehouse everything
// under a single variable. Say you have:
export const a = 'A'
export const b = 'B'


// Then you can import all exports under a single variable
// with the usage of * as:
import * as sourceFileWithoutDefault from './sourceFileWithoutDefault'

console.log(sourceFileWithoutDefault.a) // 'A'
console.log(sourceFileWithoutDefault.b) // 'B'

// You can use this approach even if there is a default export:
import * as sourceFile from './sourceFile'

// Default exports are under the variable default:
console.log(sourceFile.default) // { variableName: 'variableValue' }

// As well as named exports:
console.log(sourceFile.variableName) // 'variableValue

How can I make the computer beep in C#?

In .Net 2.0, you can use Console.Beep().

// Default beep

You can also specify the frequency and length of the beep in milliseconds.

// Beep at 5000 Hz for 1 second
Console.Beep(5000, 1000);

For more information refer

Excel VBA - read cell value from code

I think you need this ..

Dim n as Integer   

For n = 5 to 17
  msgbox cells(n,3) '--> sched waste
  msgbox cells(n,4) '--> type of treatm
  msgbox format(cells(n,5),"dd/MM/yyyy") '--> Lic exp
  msgbox cells(n,6) '--> email col

Linear regression with matplotlib / numpy

This code:

from scipy.stats import linregress

linregress(x,y) #x and y are arrays or lists.

gives out a list with the following:

slope : float
slope of the regression line
intercept : float
intercept of the regression line
r-value : float
correlation coefficient
p-value : float
two-sided p-value for a hypothesis test whose null hypothesis is that the slope is zero
stderr : float
Standard error of the estimate


Angular JS - angular.forEach - How to get key of the object?

var obj = {name: 'Krishna', gender: 'male'};
angular.forEach(obj, function(value, key) {
    console.log(key + ': ' + value);

yields the attributes of obj with their respective values:

name: Krishna
gender: male

How to specify font attributes for all elements on an html web page?

I can't stress this advice enough: use a reset stylesheet, then set everything explicitly. It'll cut your cross-browser CSS development time in half.

Try Eric Meyer's reset.css.

Bootstrap Modal before form Submit

$('form button[type="submit"]').on('click', function () {

"unable to locate adb" using Android Studio

  1. on your android studio at the top right corner beside the search icon you can find the SDK Manager.
  2. view android SDK location (this will show you your sdk path)
  3. navigate to file explorer on your system, and locate the file path, this should be found something like Windows=> c://Users/johndoe/AppData/local/android (you can now see the sdk.) Mac=>/Users/johndoe/Library/Android/sdk
  4. check the platform tools folder and see if you would see anything like adb.exe (it should be missing probably because it was corrupted and your antivirus or windows defender has quarantined it)
  5. delete the platform tools folder
  6. go back to android studio and from where you left off navigate to sdk tools (this should be right under android sdk location)
  7. uncheck android sdk platform-tools and select ok. (this will uninstall the platform tools from your ide) wait till it is done and then your gradle will sync.
  8. after sync is complete, go back and check the box of android sdk platform-tools (this will install a fresh one with new adb.exe) wait till it is done and sync project and then you are good to go.

I hope this saves someone some hours of pain.


If you are to use the Codeigniter framework then just make this into config file:

$config['compress_output'] = FALSE;

And in php.ini configuration file, use:


how to parse json using groovy

        def jsonFile = new File('File Path');
        JsonSlurper jsonSlurper = new JsonSlurper();
        def parseJson = jsonSlurper.parse(jsonFile)
        String json = JsonOutput.toJson(parseJson)
        def prettyJson = JsonOutput.prettyPrint(json)

Getting Error:JRE_HOME variable is not defined correctly when trying to run startup.bat of Apache-Tomcat

Got the solution and it's working fine. Set the environment variables as:

  • CATALINA_HOME=C:\Program Files\Java\apache-tomcat-7.0.59\apache-tomcat-7.0.59 (path where your Apache Tomcat is)
  • JAVA_HOME=C:\Program Files\Java\jdk1.8.0_25; (path where your JDK is)
  • JRE_Home=C:\Program Files\Java\jre1.8.0_25; (path where your JRE is)

Changing width property of a :before css selector using JQuery

One option is to use an attribute on the image, and modify that using jQuery. Then take that value in CSS:

HTML (note I'm assuming .cloumn is a div but it could be anything):

<div class="column" bf-width=100 >
    <img src="..." />


// General use:
$('.column').attr('bf-width', 100);
// With your image, along the lines of:
$('.column').attr('bf-width', $('img').width());

And then in order to use that value in CSS:

.column:before {
    content: attr(data-content) 'px';
    /* ... */

This will grab the attribute value from .column, and apply it on the before.

Sources: CSS attr (note the examples with before), jQuery attr.

Force browser to refresh css, javascript, etc

If you can write php, you can write:

<script src="foo.js<?php echo '?'.mt_rand(); ?>" ></script>
<link rel="stylesheet" type="text/css" href="foo.css<?php echo '?'.mt_rand(); ?>" />
<img src="foo.png<?php echo '?'.mt_rand(); ?>" />

It will always refresh!

EDIT: Of course, it's not really practical for a whole website, since you would not add this manually for everything.

Angular EXCEPTION: No provider for Http

Add HttpModule to imports array in app.module.ts file before you use it.

import { HttpModule } from '@angular/http';_x000D_
  declarations: [_x000D_
  imports: [_x000D_
 HttpModule  _x000D_
  providers: [],_x000D_
  bootstrap: [AppComponent]_x000D_
export class AppModule { }

Matplotlib: ValueError: x and y must have same first dimension

Changing your lists to numpy arrays will do the job!!

import matplotlib.pyplot as plt
from scipy import stats
import numpy as np 

x = np.array([0.46,0.59,0.68,0.99,0.39,0.31,1.09,0.77,0.72,0.49,0.55,0.62,0.58,0.88,0.78]) # x is a numpy array now
y = np.array([0.315,0.383,0.452,0.650,0.279,0.215,0.727,0.512,0.478,0.335,0.365,0.424,0.390,0.585,0.511]) # y is a numpy array now
xerr = [0.01]*15
yerr = [0.001]*15

plt.rc('font', family='serif', size=13)
m, b = np.polyfit(x, y, 1)
plt.plot(x, m*x + b, 'r-') #BREAKS ON THIS LINE
plt.xlabel('$\Delta t$ $(s)$',fontsize=20)
plt.ylabel('$\Delta p$ $(hPa)$',fontsize=20)
plt.autoscale(enable=True, axis=u'both', tight=False)

enter image description here

Using ZXing to create an Android barcode scanning app

If you want to include into your code and not use the IntentIntegrator that the ZXing library recommend, you can use some of these ports:

I use the first, and it works perfectly! It has a sample project to try it on.

Filter Extensions in HTML form upload

The accept attribute expects MIME types, not file masks. For example, to accept PNG images, you'd need accept="image/png". You may need to find out what MIME type the browser considers your file type to be, and use that accordingly. However, since a 'drp' file does not appear standard, you might have to accept a generic MIME type.

Additionally, it appears that most browsers may not honor this attribute.

The better way to filter file uploads is going to be on the server-side. This is inconvenient since the occasional user might waste time uploading a file only to learn they chose the wrong one, but at least you'll have some form of data integrity.

Alternatively you may choose to do a quick check with JavaScript before the form is submitted. Just check the extension of the file field's value to see if it is ".drp". This is probably going to be much more supported than the accept attribute.

How can I preview a merge in git?

I do not want to use the git merge command as the precursor to reviewing conflicting files. I don't want to do a merge, I want to identify potential problems before I merge - problems that auto-merge might hide from me. The solution I have been searching for is how to have git spit out a list of files that have been changed in both branches that will be merged together in the future, relative to some common ancestor. Once I have that list, I can use other file comparison tools to scout things out further. I have searched multiple times, and I still haven't found what I want in a native git command.

Here is my workaround, in case it helps anyone else out there:

In this scenario I have a branch called QA that has many changes in it since the last production release. Our last production release is tagged with "15.20.1". I have another development branch called new_stuff that I want to merge into the QA branch. Both QA and new_stuff point to commits that "follow" (as reported by gitk) the 15.20.1 tag.

git checkout QA
git pull
git diff 15.20.1 --name-only > QA_files
git checkout new_stuff
git pull
git diff 15.20.1 --name-only > new_stuff_files
comm -12 QA_files new_stuff_files

Here are some discussions that hit on why I'm interested in targeting these specific files:

How can I trust Git merge?

Argument list too long error for rm, cp, mv commands

If they are filenames with spaces or special characters, use:

find -maxdepth 1 -name '*.pdf' -exec rm "{}" \;

This sentence search all files in the current directory (-maxdepth 1) with extension pdf (-name '*.pdf'), and then, delete each one (-exec rm "{}").

The expression {} replace the name of the file, and, "{}" set the filename as string, including spaces or special characters.

How to center a (background) image within a div?

try background-position:center;

EDIT: since this question is getting lots of views, its worth adding some extra info:

text-align: center will not work because the background image is not part of the document and is therefore not part of the flow.

background-position:center is shorthand for background-position: center center; (background-position: horizontal vertical);

Python: Converting from ISO-8859-1/latin1 to UTF-8

concept = concept.encode('ascii', 'ignore') 
concept = MySQLdb.escape_string(concept.decode('latin1').encode('utf8').rstrip())

I do this, I am not sure if that is a good approach but it works everytime !!

How to describe table in SQL Server 2008?

You can use keyboard short-cut for Description/ detailed information of Table in SQL Server 2008.

Follow steps:

  1. Write Table Name,
  2. Select it, and press Alt + F1
  3. It will show detailed information/ description of mentioned table as,

    1) Table created date,
    2) Columns Description,
    3) Identity,
    4) Indexes,
    5) Constraints,
    6) References etc. As shown Below [example]:

Alt+F1 Demo

How to run PyCharm in Ubuntu - "Run in Terminal" or "Run"?

To make it a bit more user-friendly: After you've unpacked it, go into the directory, and run bin/ Once it opens, it either offers you to create a desktop entry, or if it doesn't, you can ask it to do so by going to the Tools menu and selecting Create Desktop Entry...

Then close PyCharm, and in the future you can just click on the created menu entry. (or copy it onto your Desktop)

To answer the specifics between Run and Run in Terminal: It's essentially the same, but "Run in Terminal" actually opens a terminal window first and shows you console output of the program. Chances are you don't want that :)

(Unless you are trying to debug an application, you usually do not need to see the output of it.)

Plot different DataFrames in the same figure

If you a running Jupyter/Ipython notebook and having problems using;

ax = df1.plot()


Run the command inside of the same cell!! It wont, for some reason, work when they are separated into sequential cells. For me at least.

Renaming the current file in Vim

  • Write the file while editing - :w newname - to create a copy.
  • Start editing the new copy - :e#.
  • (Optionally) remove the old copy - :!rm oldname.

On Windows, the optional 3rd step changes a little:

  • (Optionally) remove old Windows copy - :!del oldname.

addEventListener for keydown on Canvas

encapsulate all of your js code within a window.onload function. I had a similar issue. Everything is loaded asynchronously in javascript so some parts load quicker than others, including your browser. Putting all of your code inside the onload function will ensure everything your code will need from the browser will be ready to use before attempting to execute.

TypeError: Object of type 'bytes' is not JSON serializable

I was dealing with this issue today, and I knew that I had something encoded as a bytes object that I was trying to serialize as json with json.dump(my_json_object, write_to_file.json). my_json_object in this case was a very large json object that I had created, so I had several dicts, lists, and strings to look at to find what was still in bytes format.

The way I ended up solving it: the write_to_file.json will have everything up to the bytes object that is causing the issue.

In my particular case this was a line obtained through

for line in text:
    json_object['line'] = line.strip()

I solved by first finding this error with the help of the write_to_file.json, then by correcting it to:

for line in text:
    json_object['line'] = line.strip().decode()

Spring Boot application as a Service

I don't know of a "standard" shrink-wrapped way to do that with a Java app, but it's definitely a good idea (you want to benefit from the keep-alive and monitoring capabilities of the operating system if they are there). It's on the roadmap to provide something from the Spring Boot tool support (maven and gradle), but for now you are probably going to have to roll your own. The best solution I know of right now is Foreman, which has a declarative approach and one line commands for packaging init scripts for various standard OS formats (monit, sys V, upstart etc.). There is also evidence of people having set stuff up with gradle (e.g. here).

How can I enable auto complete support in Notepad++?

Open Notepad++ and Settings -> Preferences -> Auto-Completion -> Check the Auto-insert options you want. this link will help alot:

jQuery UI - Draggable is not a function?

This may be helpful for some one :

In my case i was able to remove this error by first loading the js files on which draggable depends. They were ui.mouse.js, ui.core and ui.widget i.e UI Core Widget Factory Mouse Interaction

Make sure the script tag for loading dependencies lies above the draggable js loading tag.

Find an element by class name, from a known parent element

You were close. You can do:

var element = $("#parentDiv").find(".myClassNameOfInterest");

Alternatively, you can do:

var element = $(".myClassNameOfInterest", "#parentDiv");

...which sets the context of the jQuery object to the #parentDiv.


Additionally, it may be faster in some browsers if you do div.myClassNameOfInterest instead of just .myClassNameOfInterest.

Mockito: Mock private field initialization

Following code can be used to initialize mapper in REST client mock. The mapper field is private and needs to be set during unit test setup.

import org.mockito.internal.util.reflection.FieldSetter;

new FieldSetter(client, Client.class.getDeclaredField("mapper")).set(new Mapper());

How do I specify different layouts for portrait and landscape orientations?

Fastest way for Android Studio 3.x.x and Android Studio 4.x.x

1.Go to the design tab of the activity layout

2.At the top you should press on the orientation for preview button, there is a option to create a landscape layout (check image), a new folder will be created as your xml layout file for that particular orientation

enter image description here

Why does PEP-8 specify a maximum line length of 79 characters?

I believe those who study typography would tell you that 66 characters per a line is supposed to be the most readable width for length. Even so, if you need to debug a machine remotely over an ssh session, most terminals default to 80 characters, 79 just fits, trying to work with anything wider becomes a real pain in such a case. You would also be suprised by the number of developers using vim + screen as a day to day environment.

How can you test if an object has a specific property?

Just check against null.

($myObject.MyProperty -ne $null)

If you have not set PowerShell to StrictMode, this works even if the property does not exist:

$obj = New-Object PSObject;                                                   
Add-Member -InputObject $obj -MemberType NoteProperty -Name Foo -Value "Bar";
$obj.Foo; # Bar                                                                  
($obj.MyProperty -ne $null);  # False, no exception

How to use cookies in Python Requests

From the documentation:

  1. get cookie from response

    url = ''
    r = requests.get(url)

    {'example_cookie_name': 'example_cookie_value'}

  2. give cookie back to server on subsequent request

    url = ''
    cookies = dict(cookies_are='working')
    r = requests.get(url, cookies=cookies)`

Local and global temporary tables in SQL Server

  • Table variables (DECLARE @t TABLE) are visible only to the connection that creates it, and are deleted when the batch or stored procedure ends.

  • Local temporary tables (CREATE TABLE #t) are visible only to the connection that creates it, and are deleted when the connection is closed.

  • Global temporary tables (CREATE TABLE ##t) are visible to everyone, and are deleted when all connections that have referenced them have closed.

  • Tempdb permanent tables (USE tempdb CREATE TABLE t) are visible to everyone, and are deleted when the server is restarted.

Cannot install packages inside docker Ubuntu image

I found that mounting a local volume over /tmp can cause permission issues when the "apt-get update" runs, which prevents the package cache from being populated. Hopefully, this isn't something most people do, but it's something else to look for if you see this issue.

JPanel vs JFrame in Java

JFrame is the window; it can have one or more JPanel instances inside it. JPanel is not the window.

You need a Swing tutorial:

Github: error cloning my private repository

I found a good solution for adding/updating the CA certificates on RHEL/CentOS 6 which is the root cause reported issue.

Since they become outdated distros, the cacert authorities in that system has not been updated until executing the command sudo yum update.

Didn't realize the issue until the GIT_CURL_VERBOSE mode shows the cacert path issue.

java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory

The perfect solution which works undoubtedly is to just add these packages to your app:

after adding so you may encounter following WARNING which you can simply ignore!

SLF4J: No SLF4J providers were found. SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See for further details.


How to align form at the center of the page in html/css

Or you can just use the <center></center> tags.

Remove file from SVN repository without deleting local copy

When you want to remove one file from SVN:

  1. Go to workspace path where the file is located.
  2. Delete that file from the folder (
  3. Right click and commit, then a window will open.
  4. Select the file you deleted ( from the folder, and again right click and delete.. it will remove the file from SVN.

Rounding up to next power of 2

You might find the following clarification to be helpful towards your purpose:

jQuery append() - return appended elements

I think you could do something like this:

var $child = $("#parentId").append("<div></div>").children("div:last-child");

The parent #parentId is returned from the append, so add a jquery children query to it to get the last div child inserted.

$child is then the jquery wrapped child div that was added.

how to generate web service out of wsdl

How about using the wsdl /server or wsdl /serverinterface switches? As far as I understand the wsdl.exe command line properties, that's what you're looking for.



Server switch has been deprecated. Please use /serverInterface instead.
Generate an abstract class for an xml web service implementation using
ASP.NET based on the contracts. The default is to generate client proxy

On the other hand: why do you want to create obsolete technology solutions? Why not create this web service as a WCF service. That's the current and more modern, much more flexible way to do this!



When I use wsdl /server on a WSDL file, I get this file created:

public abstract partial class OneCrmServiceType : System.Web.Services.WebService 
    /// <remarks/>
    public abstract void OrderCreated(......);

This is basically almost exactly the same code that gets generated when you add an ASMX file to your solution (in the code behind file - "yourservice.asmx.cs"). I don't think you can get any closer to creating an ASMX file from a WSDL file.

You can always add the "yourservice.asmx" manually - it doesn't really contain much:

<%@ WebService Language="C#" CodeBehind="YourService.asmx.cs" 
      Class="YourServiceNamespace.YourServiceClass" %>

How to make a vertical SeekBar in Android?

I tried in many different ways, but the one which worked for me was. Use Seekbar inside FrameLayout


And in Code.

Setup Pre Draw callback on Seekbar, Where you can change the Width and height of the Seekbar I did this part in c#, so Code i used was

            var volumeSlider = view.FindViewById<SeekBar>(Resource.Id.home_link_volume);

            var volumeFrameLayout = view.FindViewById<FrameLayout>(Resource.Id.linkVolumeFrameLayout);

            void OnPreDrawVolume(object sender, ViewTreeObserver.PreDrawEventArgs e)
                volumeSlider.ViewTreeObserver.PreDraw -= OnPreDrawVolume;
                var h = volumeFrameLayout.Height;
                volumeSlider.Rotation = 270.0f;
                volumeSlider.LayoutParameters.Width = h;

            volumeSlider.ViewTreeObserver.PreDraw += OnPreDrawVolume;

Here i Add listener to PreDraw Event and when its triggered, I remove the PreDraw so that it doesnt go into Infinite loop.

So when Pre Draw gets executed, I fetch the Height of FrameLayout and assign it to Seekbar. And set the rotation of seekbar to 270. As my seekbar is inside frame Layout and its Gravity is set as Center. I dont need to worry about the Translation. As Seekbar always stay in middle of Frame Layout.

Reason i remove EventHandler is because seekbar.RequestLayout(); Will make this event to be executed again.

Can a constructor in Java be private?

yes a constructor can be private. A private Constructor prevents any other class from instantiating example of private constructor

public class CustomHttpClient {
private static HttpClient customHttpClient;

/** A private Constructor prevents any other class from instantiating. */
private CustomHttpClient() {

what is Promotional and Feature graphic in Android Market/Play Store?

I found this nice write-up that clears it up pretty nicely:

The different graphic assets we request are used to highlight and promote your application in Android Market, and possibly other Google-owned properties. If you’d like to restrict the marketing of your app to just Android Market, you have the option of opting-out of marketing by selecting the "Marketing Opt-Out" in the Developer Console.

Screenshots (Required):
We require 2 screenshots.
Use: Displayed on the details page for your application in Android Market.
You may upload up to 8 screenshots.
Specs: 320w x 480h, 480w x 800h, or 480w x 854h; 24 bit PNG or JPEG (no alpha) Full bleed, no border in art.
Landscape thumbnails are cropped, but we preserve the image’s full size and aspect ratio if the user opens it up on market client.
High Resolution Application Icon (Required):
Use: In various locations in Android Market.
Does not replace your launcher icon.
Specs: 512x512, 32-bit PNG with alpha; Max size of 1024KB.
This does not replace your launcher icon, but should be a higher-fidelity, higher-resolution version of your application icon.
Same safe-frame as current launcher guidelines, just scaled up:
Full Asset: 512 x 512 px.
Circle or non-square icons: 426 x 426 px, centered within the PNG.
Square Icons: 398 x 398 px.
Drop shadow: black, 75% opaque, 90 degrees down, distance of 14px, size of 36px.
Tweak as necessary to fit icon style (e.g., Google Maps icon has a drop shadow of varying height).
Promotional Graphic (Optional):
Use: In various locations in Android Market.
Specs: 180w x 120h, 24 bit PNG or JPEG (no alpha), Full bleed, no border in art.
Feature Graphic (Optional):
Use: The featured section in Android Market. Will be downsized to mini or micro.
Specs: 1024w x 500h, 24 bit PNG or JPEG (no alpha) with no transparency
Use a safe frame of 924x400 (50 pixel of safe padding on each side). All the important content of the graphic should be within this safe frame. Pixels outside of this safe frame may be cropped for stylistic purposes.
If incorporating text, use large font sizes, and keep the graphic simple, as this graphic may be scaled down from its original size.
This graphic may be displayed alone without the app icon.
Video Link (Optional):
Specs: Enter the URL to a YouTube video showcasing your app.
Short videos (30 seconds - 2 minutes) highlighting the top features of your app work best.

CSS vertical alignment of inline/inline-block elements

For fine tuning the position of an inline-block item, use top and left:

  position: relative;
  top: 5px;
  left: 5px;

Thanks CSS-Tricks!

How to format dateTime in django template?

You can use this:

addedDate =

Authenticate Jenkins CI for Github private repository

Perhaps GitHub's support for deploy keys is what you're looking for? To quote that page:

When should I use a deploy key?

Simple, when you have a server that needs pull access to a single private repo. This key is attached directly to the repository instead of to a personal user account.

If that's what you're already trying and it doesn't work, you might want to update your question with more details of the URLs being used, the names and location of the key files, etc.

Now for the technical part: How to use your SSH key with Jenkins?

If you have, say, a jenkins unix user, you can store your deploy key in ~/.ssh/id_rsa. When Jenkins tries to clone the repo via ssh, it will try to use that key.

In some setups, you cannot run Jenkins as an own user account, and possibly also cannot use the default ssh key location ~/.ssh/id_rsa. In such cases, you can create a key in a different location, e.g. ~/.ssh/deploy_key, and configure ssh to use that with an entry in ~/.ssh/config:

Host github-deploy-myproject
    User           git
    IdentityFile   ~/.ssh/deploy_key
    IdentitiesOnly yes

Because all you authenticate to all Github repositories using [email protected] and you don't want the above key to be used for all your connections to Github, we created a host alias github-deploy-myproject. Your clone URL now becomes

git clone github-deploy-myproject:myuser/myproject

and that is also what you put as repository URL into Jenkins.

(Note that you must not put ssh:// in front in order for this to work.)

entity framework Unable to load the specified metadata resource

Craig Stuntz has written an extensive (in my opinion) blog post on troubleshooting this exact error message, I personally would start there.

The following res: (resource) references need to point to your model.

<add name="Entities" connectionString="metadata=

Make sure each one has the name of your .edmx file after the "*/", with the "edmx" changed to the extension for that res (.csdl, .ssdl, or .msl).

It also may help to specify the assembly rather than using "//*/".

Worst case, you can check everything (a bit slower but should always find the resource) by using

<add name="Entities" connectionString="metadata=
        res://*/;provider= <!-- ... -->

How to duplicate sys.stdout to a log file?

As described elsewhere, perhaps the best solution is to use the logging module directly:

import logging

logging.basicConfig(level=logging.DEBUG, filename='mylog.log')'this should to write to the log file')

However, there are some (rare) occasions where you really want to redirect stdout. I had this situation when I was extending django's runserver command which uses print: I didn't want to hack the django source but needed the print statements to go to a file.

This is a way of redirecting stdout and stderr away from the shell using the logging module:

import logging, sys

class LogFile(object):
    """File-like object to log text using the `logging` module."""

    def __init__(self, name=None):
        self.logger = logging.getLogger(name)

    def write(self, msg, level=logging.INFO):
        self.logger.log(level, msg)

    def flush(self):
        for handler in self.logger.handlers:

logging.basicConfig(level=logging.DEBUG, filename='mylog.log')

# Redirect stdout and stderr
sys.stdout = LogFile('stdout')
sys.stderr = LogFile('stderr')

print 'this should to write to the log file'

You should only use this LogFile implementation if you really cannot use the logging module directly.

Is it possible to assign numeric value to an enum in Java?

public enum EXIT_CODE {
    A(104), B(203);

    private int numVal;

    EXIT_CODE(int numVal) {
        this.numVal = numVal;

    public int getNumVal() {
        return numVal;

Using Excel VBA to run SQL query

Below is code that I currently use to pull data from a MS SQL Server 2008 into VBA. You need to make sure you have the proper ADODB reference [VBA Editor->Tools->References] and make sure you have Microsoft ActiveX Data Objects 2.8 Library checked, which is the second from the bottom row that is checked (I'm using Excel 2010 on Windows 7; you might have a slightly different ActiveX version, but it will still begin with Microsoft ActiveX):

References required for SQL

Sub Module for Connecting to MS SQL with Remote Host & Username/Password

Sub Download_Standard_BOM()
'Initializes variables
Dim cnn As New ADODB.Connection
Dim rst As New ADODB.Recordset
Dim ConnectionString As String
Dim StrQuery As String

'Setup the connection string for accessing MS SQL database
   'Make sure to change:
       '1: PASSWORD
       '2: USERNAME
       '4: DATABASE
    ConnectionString = "Provider=SQLOLEDB.1;Password=PASSWORD;Persist Security Info=True;User ID=USERNAME;Data Source=REMOTE_IP_ADDRESS;Use Procedure for Prepare=1;Auto Translate=True;Packet Size=4096;Use Encryption for Data=False;Tag with column collation when possible=False;Initial Catalog=DATABASE"

    'Opens connection to the database
    cnn.Open ConnectionString
    'Timeout error in seconds for executing the entire query; this will run for 15 minutes before VBA timesout, but your database might timeout before this value
    cnn.CommandTimeout = 900

    'This is your actual MS SQL query that you need to run; you should check this query first using a more robust SQL editor (such as HeidiSQL) to ensure your query is valid
    StrQuery = "SELECT TOP 10 * FROM tbl_table"

    'Performs the actual query
    rst.Open StrQuery, cnn
    'Dumps all the results from the StrQuery into cell A2 of the first sheet in the active workbook
    Sheets(1).Range("A2").CopyFromRecordset rst
End Sub

How do I copy a version of a single file from one git branch to another?

Run this from the branch where you want the file to end up:

git checkout otherbranch myfile.txt

General formulas:

git checkout <commit_hash> <relative_path_to_file_or_dir>
git checkout <remote_name>/<branch_name> <file_or_dir>

Some notes (from comments):

  • Using the commit hash you can pull files from any commit
  • This works for files and directories
  • overwrites the file myfile.txt and mydir
  • Wildcards don't work, but relative paths do
  • Multiple paths can be specified

an alternative:

git show commit_id:path/to/file > path/to/file

Convert java.util.Date to java.time.LocalDate

You can convert in one line :

public static LocalDate getLocalDateFromDate(Date date){
   return LocalDate.from(Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()));

bash: Bad Substitution

For others that arrive here, this exact message will also appear when using the env variable syntax for commands, for example ${which sh} instead of the correct $(which sh)

How to replace negative numbers in Pandas Data Frame by zero

With lambda function

df['column'] = df['column'].apply(lambda x : x if x > 0 else 0)

Ajax passing data to php script

You can also use bellow code for pass data using ajax.

var dataString = "album" + title;
    type: 'POST',  
    url: 'test.php', 
    data: dataString,
    success: function(response) {

Accessing nested JavaScript objects and arrays by string path

Note that the following will not work for all valid unicode property names (but neither will any of the other answers as far as I can tell).

const PATTERN = /[\^|\[|\.]([$|\w]+)/gu

function propValue(o, s) {
    const names = []
    for(let [, name] of [...s.matchAll(PATTERN)]) 
    return names.reduce((p, propName) => {
            throw 'invalid property name'
        return p[propName]
    }, o)

let path = 'myObject.1._property2[0][0].$property3'
let o = {
    1: {
        _property2: [
                $property3: 'Hello World'
console.log(propValue(o, path)) // 'Hello World'

How to locate and insert a value in a text box (input) using Python Selenium?

Assuming your page is available under ""

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()

Select element by id:

inputElement = driver.find_element_by_id("a1")

Now you can simulate hitting ENTER:


or if it is a form you can submit:


React JS get current date

Your problem is that you are naming your component class Date. When you call new Date() within your class, it won't create an instance of the Date you expect it to create (which is likely this Date)- it will try to create an instance of your component class. Then the constructor will try to create another instance, and another instance, and another instance... Until you run out of stack space and get the error you're seeing.

If you want to use Date within your class, try naming your class something different such as Calendar or DateComponent.

The reason for this is how JavaScript deals with name scope: Whenever you create a new named entity, if there is already an entity with that name in scope, that name will stop referring to the previous entity and start referring to your new entity. So if you use the name Date within a class named Date, the name Date will refer to that class and not to any object named Date which existed before the class definition started.

Div Size Automatically size of content

If you are coming here, there is high chance width: min-content or width: max-content can fix your problem. This can force an element to use the smallest or largest space the browser could choose…

This is the modern solution. Here is a small tutorial for that.

There is also fit-content, which often works like min-content, but is more flexible. (But also has worse browser support.)

This is a quite new feature and some browsers do not support it yet, but browser support is growing. See the current browser status here.

Scala Doubles, and Precision

A bit strange but nice. I use String and not BigDecimal

def round(x: Double)(p: Int): Double = {
    var A = x.toString().split('.')
    (A(0) + "." + A(1).substring(0, if (p > A(1).length()) A(1).length() else p)).toDouble

Convert DataTable to CSV stream

I don't know if this converted from VB to C# ok but if you don't want quotes around your numbers, you might compare the data type as follows..

public string DataTableToCSV(DataTable dt)
    StringBuilder sb = new StringBuilder();
    if (dt == null)
        return "";

    try {
        // Create the header row
        for (int i = 0; i <= dt.Columns.Count - 1; i++) {
            // Append column name in quotes
            sb.Append("\"" + dt.Columns[i].ColumnName + "\"");
            // Add carriage return and linefeed if last column, else add comma
            sb.Append(i == dt.Columns.Count - 1 ? "\n" : ",");

        foreach (DataRow row in dt.Rows) {
            for (int i = 0; i <= dt.Columns.Count - 1; i++) {
                // Append value in quotes
                //sb.Append("""" & row.Item(i) & """")

                // OR only quote items that that are equivilant to strings
                sb.Append(object.ReferenceEquals(dt.Columns[i].DataType, typeof(string)) || object.ReferenceEquals(dt.Columns[i].DataType, typeof(char)) ? "\"" + row[i] + "\"" : row[i]);

                // Append CR+LF if last field, else add Comma
                sb.Append(i == dt.Columns.Count - 1 ? "\n" : ",");
        return sb.ToString;
    } catch (Exception ex) {
        // Handle the exception however you want
        return "";


How do I evenly add space between a label and the input field regardless of length of text?

You can also used below code

            float: left;
            width: 113px;
  <form action="yourclassName.jsp">
    <span class="labelClass">First name: </span><input type="text" name="fname"><br>
    <span class="labelClass">Last name: </span><input type="text" name="lname"><br>
    <input type="submit" value="Submit">

Download a file by jQuery.Ajax

It is certain that you can not do it through Ajax call.

However, there is a workaround.

Steps :

If you are using form.submit() for downloading the file, what you can do is :

  1. Create an ajax call from client to server and store the file stream inside the session.
  2. Upon "success" being returned from server, call your form.submit() to just stream the file stream stored in the session.

This is helpful in case when you want to decide whether or not file needs to be downloaded after making form.submit(), eg: there can be a case where on form.submit(), an exception occurs on the server side and instead of crashing, you might need to show a custom message on the client side, in such case this implementation might help.

Multiple inheritance for an anonymous class

// The interface
interface Blah {
    void something();


// Something that expects an object implementing that interface
void chewOnIt(Blah b) {


// Let's provide an object of an anonymous class
    new Blah() {
        void something() { System.out.println("Anonymous something!"); }

SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) symfony2

This is due to your mysql configuration. According to this error you are trying to connect with the user 'root' to the database host 'localhost' on a database namend 'sgce' without being granted access rights.

Presuming you did not configure your mysql instance. Log in as root user and to the folloing:


CREATE USER 'root'@'localhost' IDENTIFIED BY 'mikem';
GRANT ALL PRIVILEGES ON sgce. * TO 'root'@'localhost';

Also add your database_port in the parameters.yml. By default mysql listens on 3306:

database_port: 3306

Filtering by Multiple Specific Model Properties in AngularJS (in OR relationship)

There are a bunch of good solutions here but I'd suggest going the other route with this. If searching is the most important thing and the 'secret' property is not used on the view at all; my approach for this would be to use the built-in angular filter with all its benefits and simply map the model to a new array of objects.

Example from the question:

$scope.people = { 
                              return { 

Now, in html simply use the regular filter to search both these properties.

<div ng-repeat="member in people | filter: searchString">

When running WebDriver with Chrome browser, getting message, "Only local connections are allowed" even though browser launches properly

I had to run my commands in the one and same terminal, not seperately.

nohup sudo Xvfb :10 -ac
export DISPLAY=:10
java -jar vendor/se/selenium-server-standalone/bin/selenium-server-standalone.jar"/usr/bin/google-chrome""vendor/bin/chromedriver"

Error: Unable to run mksdcard SDK tool

if you do this: sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0 lib32stdc++6. You may get this error:

E: Unable to locate package lib32bz2-1.0

E: Couldn't find any package by glob 'lib32bz2-1.0'

E: Couldn't find any package by regex 'lib32bz2-1.0'

So i suggest just doing this:

sudo apt-get install lib32stdc++6

And also, the AOSP should look for how while installing Android-Studio, that is installed too.

Float a div in top right corner without overlapping sibling header

section {
    position: relative;
    width: 50%;
    border: 1px solid;
h1 {
    display: inline;
div {
    position: relative;
    top: 0;
    right: 0;


Java regex to extract text between tags

Try this:

Pattern p = Pattern.compile(?<=\\<(any_tag)\\>)(\\s*.*\\s*)(?=\\<\\/(any_tag)\\>);
Matcher m = p.matcher(anyString);

For example:

String str = "<TR> <TD>1Q Ene</TD> <TD>3.08%</TD> </TR>";
Pattern p = Pattern.compile("(?<=\\<TD\\>)(\\s*.*\\s*)(?=\\<\\/TD\\>)");
Matcher m = p.matcher(str);
   Log.e("Regex"," Regex result: " +       


10 Ene


Should I use window.navigate or document.location in JavaScript?

window.location.href = 'URL';

is the standard implementation for changing the current window's location.

How can I start InternetExplorerDriver using Selenium WebDriver

Enable protected mode for all zones You need to enable protected mode for all zones from Internet Options -> Security tab. To enable protected mode for all zones.

How to modify existing, unpushed commit messages?

I use the Git GUI as much as I can, and that gives you the option to amend the last commit:

Tick that box

Also, git rebase -i origin/masteris a nice mantra that will always present you with the commits you have done on top of master, and give you the option to amend, delete, reorder or squash. No need to get hold of that hash first.

How to get EditText value and display it on screen through TextView?

    new View.OnClickListener()
        public void onClick(View view)
            String s1=tt.getText().toString();

Google Maps API v3: InfoWindow not sizing correctly

I couldnt get it to work in any way shape or form, I was including 3 divs into the box. I wrapped them in an outer div, with widths and heights all set correctly, and nothing worked.

In the end I fixed it by setting the div as absolute top left, and then before the div, I set two images, one 300px wide and 1px high, one 120px high and 1px wide, of a transparent gif.

It scaled properly then!

Its ugly but it works.

You could also do one image and set a zindex I expect, or even just one image if your window has no interaction, but this was containing a form, so, that wasn't an option...

Iterate over a Javascript associative array in sorted order

I really like @luke-schafer's prototype idea, but also hear what he is saying about the issues with prototypes. What about using a simple function?

function sortKeysAndDo( obj, worker ) {_x000D_
  var keys = Object.keys(obj);_x000D_
  for (var i = 0; i < keys.length; i++) {_x000D_
     worker(keys[i], obj[keys[i]]);_x000D_
function show( key, value ) {_x000D_
  document.write( key + ' : ' + value +'<br>' );_x000D_
var a = new Array();_x000D_
a['b'] = 1;_x000D_
a['z'] = 1;_x000D_
a['a'] = 1;_x000D_
sortKeysAndDo( a, show);_x000D_
var my_object = { 'c': 3, 'a': 1, 'b': 2 };_x000D_
sortKeysAndDo( my_object, show);

This seems to eliminate the issues with prototypes and still provide a sorted iterator for objects. I am not really a JavaScript guru, though, so I'd love to know if this solution has hidden flaws I missed.

Cannot read property 'style' of undefined -- Uncaught Type Error

Add your <script> to the bottom of your <body>, or add an event listener for DOMContentLoaded following this StackOverflow question.

If that script executes in the <head> section of the code, document.getElementsByClassName(...) will return an empty array because the DOM is not loaded yet.

You're getting the Type Error because you're referencing search_span[0], but search_span[0] is undefined.

This works when you execute it in Dev Tools because the DOM is already loaded.

How can I simulate an array variable in MySQL?

Is an array variable really necessary?

I ask because I originally landed here wanting to add an array as a MySQL table variable. I was relatively new to database design and trying to think of how I'd do it in a typical programming language fashion.

But databases are different. I thought I wanted an array as a variable, but it turns out that's just not a common MySQL database practice.

Standard Practice

The alternative solution to arrays is to add an additional table, and then reference your original table with a foreign key.

As an example, let's imagine an application that keeps track of all the items every person in a household wants to buy at the store.

The commands for creating the table I originally envisioned would have looked something like this:

#doesn't work
  buy_list ARRAY

I think I envisioned buy_list to be a comma-separated string of items or something like that.

But MySQL doesn't have an array type field, so I really needed something like this:

  person VARCHAR(50),
  item VARCHAR(50),
  PRIMARY KEY (person, item),
  CONSTRAINT fk_person FOREIGN KEY (person) REFERENCES Person(name)

Here we define a constraint named fk_person. It says that the 'person' field in BuyList is a foreign key. In other words, it's a primary key in another table, specifically the 'name' field in the Person table, which is what REFERENCES denotes.

We also defined the combination of person and item to be the primary key, but technically that's not necessary.

Finally, if you want to get all the items on a person's list, you can run this query:

SELECT item FROM BuyList WHERE person='John';

This gives you all the items on John's list. No arrays necessary!

css - position div to bottom of containing div

.outside {
    width: 200px;
    height: 200px;
    background-color: #EEE; /*to make it visible*/

Needs to be

.outside {
    position: relative;
    width: 200px;
    height: 200px;
    background-color: #EEE; /*to make it visible*/

Absolute positioning looks for the nearest relatively positioned parent within the DOM, if one isn't defined it will use the body.

How can I make SMTP authenticated in C#

To send a message through TLS/SSL, you need to set Ssl of the SmtpClient class to true.

string to = "[email protected]";
string from = "[email protected]";
MailMessage message = new MailMessage(from, to);
message.Subject = "Using the new SMTP client.";
message.Body = @"Using this new feature, you can send an e-mail message from an application very easily.";
SmtpClient client = new SmtpClient(server);
// Credentials are necessary if the server requires the client 
// to authenticate before it will send e-mail on the client's behalf.
client.UseDefaultCredentials = true;
client.EnableSsl = true;

mysqli_real_connect(): (HY000/2002): No such file or directory

I had the same problem. In my /etc/mysql/my.cnf was no path more to mysqld.sock defined. So I started a search to find it with: find / -type s | grep mysqld.sock but it could not be found. I reinstalled mysql with: apt install mysql-server-5.7 (please check before execute the current sql-server-version).

This solved my problem.

How to declare local variables in postgresql?

Postgresql historically doesn't support procedural code at the command level - only within functions. However, in Postgresql 9, support has been added to execute an inline code block that effectively supports something like this, although the syntax is perhaps a bit odd, and there are many restrictions compared to what you can do with SQL Server. Notably, the inline code block can't return a result set, so can't be used for what you outline above.

In general, if you want to write some procedural code and have it return a result, you need to put it inside a function. For example:

  one int;
  two int;
  one := 1;
  two := 2;
  RETURN one + two;
SELECT somefuncname();

The PostgreSQL wire protocol doesn't, as far as I know, allow for things like a command returning multiple result sets. So you can't simply map T-SQL batches or stored procedures to PostgreSQL functions.

How to use HttpWebRequest (.NET) asynchronously?

By far the easiest way is by using TaskFactory.FromAsync from the TPL. It's literally a couple of lines of code when used in conjunction with the new async/await keywords:

var request = WebRequest.Create("");
var response = (HttpWebResponse) await Task.Factory
Debug.Assert(response.StatusCode == HttpStatusCode.OK);

If you can't use the C#5 compiler then the above can be accomplished using the Task.ContinueWith method:

    .ContinueWith(task =>
        var response = (HttpWebResponse) task.Result;
        Debug.Assert(response.StatusCode == HttpStatusCode.OK);

Consider defining a bean of type 'package' in your configuration [Spring-Boot]

I faced with familiar problem in my Maven multi-module project with Spring Boot 2. The problem was related to naming of my packages in sub Maven modules.

@SpringBootApplication incapsulate a lots of component like - @ComponentScan, @EnableAutoConfiguration, jpa-repositories, json-serialization and so on. And he places @ComponentScan in com.*******.space package. This part of packages com.*******.space must be common for all modules.

For fixing it:

  1. You should rename all module packages. Other words you had to have in all packages in all Maven modules - the same parent part. For example - com.*******.space
  2. Also you have to move your entry point to this package - com.*******.space

Get sum of MySQL column in PHP

$result=mysql_query("SELECT SUM(column) AS total_value FROM table name WHERE column='value'");

How do I redirect in expressjs while passing some context?

The easiest way I have found to pass data between routeHandlers to use next() no need to mess with redirect or sessions. Optionally you could just call your homeCtrl(req,res) instead of next() and just pass the req and res

var express  = require('express');
var jade     = require('jade');
var http     = require("http");

var app    = express();
var server = http.createServer(app);

// Routing //

// Move route middleware into named
// functions
function homeCtrl(req, res) {

    // Prepare the context
    var context = req.dataProcessed;
    res.render('home.jade', context);

function categoryCtrl(req, res, next) {

    // Process the data received in req.body
    // instead of res.redirect('/');
    req.dataProcessed = somethingYouDid;
    return next();
    // optionally - Same effect
    // accept no need to define homeCtrl
    // as the last piece of middleware
    // return homeCtrl(req, res, next);

app.get('/', homeCtrl);'/category', categoryCtrl, homeCtrl);

What is the difference between the dot (.) operator and -> in C++?

The -> operator is used when we are working with a pointer and the dot is used otherwise. So if we have a struct class like:

struct class{ int num_students; int yr_grad; };

and we have an instance of a class* curr_class (class pointer), then to get access to number of students we would do

cout << curr_class->num_students << endl;

In case we had a simple class object , say class_2016, we would do

cout << class_2016.num_students << endl;

For the pointer to class the -> operator is equivalent to


Note: For a class, the way to access member functions of the class will also be the same way

Restore a postgres backup file using the command line?

Backup and restore with GZIP

For larger size database this is very good


pg_dump -U user -d mydb | gzip > mydb.pgsql.gz


gunzip -c mydb.pgsql.gz | psql dbname -U user

SQL Server Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >=

WHERE columns_name
    IN ( SELECT COLUMN FROM TABLE WHERE columns_name = 'value');

note: when we are using sub-query we must focus on these points:

  1. if our sub query returns 1 value in this case we need to use (=,!=,<>,<,>....)
  2. else (more than one value), in this case we need to use (in, any, all, some )

The role of #ifdef and #ifndef

Someone should mention that in the question there is a little trap. #ifdef will only check if the following symbol has been defined via #define or by command line, but its value (its substitution in fact) is irrelevant. You could even write

#define one

precompilers accept that. But if you use #if it's another thing.

#define one 0
#if one
    printf("one evaluates to a truth ");
#if !one
    printf("one does not evaluate to truth ");

will give one does not evaluate to truth. The keyword defined allows to get the desired behaviour.

#if defined(one) 

is therefore equivalent to #ifdef

The advantage of the #if construct is to allow a better handling of code paths, try to do something like that with the old #ifdef/#ifndef pair.

#if defined(ORA_PROC) || defined(__GNUC) && __GNUC_VERSION > 300

What's the difference between Invoke() and BeginInvoke()

Just adding why and when to use Invoke().

Both Invoke() and BeginInvoke() marshal the code you specify to the dispatcher thread.

But unlike BeginInvoke(), Invoke() stalls your thread until the dispatcher executes your code. You might want to use Invoke() if you need to pause an asynchronous operation until the user has supplied some sort of feedback.

For example, you could call Invoke() to run a snippet of code that shows an OK/Cancel dialog box. After the user clicks a button and your marshaled code completes, the invoke() method will return, and you can act upon the user's response.

See Pro WPF in C# chapter 31

List of Timezone IDs for use with FindTimeZoneById() in C#?

I know it's old and old question but Microsoft appears to have provided this through MSDN now.

How to pick an image from gallery (SD Card) for my app?

call chooseImage method like-

public void chooseImage(ImageView v)
    Intent intent = new Intent(Intent.ACTION_PICK);
    startActivityForResult(intent, SELECT_PHOTO);

protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

    if(imageReturnedIntent != null)
        Uri selectedImage = imageReturnedIntent.getData();
    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK)
            Bitmap datifoto = null;
            Uri picUri = null;
            picUri = imageReturnedIntent.getData();//<- get Uri here from data intent
             if(picUri !=null){
               try {
                   datifoto = android.provider.MediaStore.Images.Media.getBitmap(this.getContentResolver(),                                 picUri);
               } catch (FileNotFoundException e) {
                  throw new RuntimeException(e);
               } catch (IOException e) {
                  throw new RuntimeException(e);
               } catch (OutOfMemoryError e) {
                Toast.makeText(getBaseContext(), "Image is too large. choose other", Toast.LENGTH_LONG).show();


        //Toast.makeText(getBaseContext(), "data null", Toast.LENGTH_SHORT).show();