Programs & Examples On #Viewusercontrol

"An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page..."

I wasn't using Azure, but I got the same error locally. Using <customErrors mode="Off" /> seemed to have no effect, but checking the Application logs in Event Viewer revealed a warning from ASP.NET which contained all the detail I needed to resolve the issue.

The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly

In case it helps, I've ran into this problem when passing null into a parameter for a generic TValue, to get around this you have to cast your null values:




How to convert View Model into JSON object in ASP.NET MVC?

Well done, you've only just started using MVC and you've found its first major flaw.

You don't really want to be converting it to JSON in the view, and you don't really want to convert it in the controller, as neither of these locations make sense. Unfortunately, you're stuck with this situation.

The best thing I've found to do is send the JSON to the view in a ViewModel, like this:

var data = somedata;
var viewModel = new ViewModel();
var serializer = new JavaScriptSerializer();
viewModel.JsonData = serializer.Serialize(data);

return View("viewname", viewModel);

then use

<%= Model.JsonData %>

in your view. Be aware that the standard .NET JavaScriptSerializer is pretty crap.

doing it in the controller at least makes it testable (although not exactly like the above - you probably want to take an ISerializer as a dependency so you can mock it)

Update also, regarding your JavaScript, it would be good practice to wrap ALL the widget JS you have above like so:

    // all js here

this way if you put multiple widgets on a page, you won't get conflicts (unless you need to access the methods from elsewhere in the page, but in that case you should be registering the widget with some widget framework anyway). It may not be a problem now, but it would be good practice to add the brackets now to save yourself muchos effort in the future when it becomes a requirement, it's also good OO practice to encapsulate the functionality.

c# dictionary one key many values

You can also use;

 List<KeyValuePair<string, string>> Mappings;

Dynamically add script tag with src that may include document.write

Here is a minified snippet, same code as Google Analytics and Facebook Pixel uses:


Replace with your script path.

How npm start runs a server on port 8000

To change the port

npm start --port 8000

How to specify a port number in SQL Server connection string?

Use a comma to specify a port number with SQL Server:,1234

It's not necessary to specify an instance name when specifying the port.

Lots more examples at It's saved me a few times.

How to convert uint8 Array to base64 Encoded String?

function Uint8ToBase64(u8Arr){
  var CHUNK_SIZE = 0x8000; //arbitrary number
  var index = 0;
  var length = u8Arr.length;
  var result = '';
  var slice;
  while (index < length) {
    slice = u8Arr.subarray(index, Math.min(index + CHUNK_SIZE, length)); 
    result += String.fromCharCode.apply(null, slice);
    index += CHUNK_SIZE;
  return btoa(result);

You can use this function if you have a very large Uint8Array. This is for Javascript, can be useful in case of FileReader readAsArrayBuffer.

How to change FontSize By JavaScript? = "25px";

use this

Git Server Like GitHub?

for simple setups, you can provide ssh access to a central server, and set up each user's working directory to push/pull from this 'origin'. That would be the most simple and common setup for small teams.

You might also look into gitosis which gives you an http server and the ability to manage it remotely. That way you don't have to grant ssh access and all that entails to each committer.

SSH Private Key Permissions using Git GUI or ssh-keygen are too open

For *nix systems, the obvious fix is chmod 600 id_rsa ofc, but on windows 7 I had to hit my head against the wall for a while, but then I found the magic solution:

go to My Computer / Right Click / Properties / Advanced System Settings / Environment Variables and DELETE the variable (possibly from both system and user environment):


Basically, its a flaw in mingw32 used by git windows binary, seeing all files 644 and all folders 755 always. Removing the environment variable does not change that behaviour, but it appearantly tells ssh.exe to ignore the problem. If you do set proper permissions to your id_rsa through explorers security settings (there really is no need to have any other user in there than your own, not "everyone", not "administrators", not "system". none. just you), you'll still be secure.

Now, why mingw32, a different system than cygwin, would make any use of the CYGWIN environment variable, is beyond me. Looks like a bug to me.

Where do I get servlet-api.jar from?

Make sure that you're using the same Servlet API specification that your Web container supports. Refer to this chart if you're using Tomcat:

The Web container that you use will definitely have the API jars you require.

Tomcat 6 for example has it in apache-tomcat-6.0.26/lib/servlet-api.jar

Get elements by attribute when querySelectorAll is not available without using libraries?

Try this - I slightly changed the above answers:

var getAttributes = function(attribute) {
    var allElements = document.getElementsByTagName('*'),
        allElementsLen = allElements.length,
        results = [];

    for(i = 0; i < allElementsLen; i += 1) {
        curElement = allElements[i];

        if(curElement.getAttribute(attribute)) {

    return results;



Why does ENOENT mean "No such file or directory"?

It's an abbreviation of Error NO ENTry (or Error NO ENTity), and can actually be used for more than files/directories.

It's abbreviated because C compilers at the dawn of time didn't support more than 8 characters in symbols.

JavaScript: Create and save file

function download(text, name, type) {_x000D_
  var a = document.getElementById("a");_x000D_
  var file = new Blob([text], {type: type});_x000D_
  a.href = URL.createObjectURL(file);_x000D_ = name;_x000D_
<a href="" id="a">click here to download your file</a>_x000D_
<button onclick="download('file text', 'myfilename.json', 'text/json')">Create file</button>

I think this can work with json files too if you change the mime type.

Clearing state es6 React

class x extends Components {
constructor() {
 this.state = {

  name: 'mark',
  age: 32,
  isAdmin: true,
  hits: 0,

  // since this.state is an object
  // simply add a method..

  resetSelectively() {
         //i don't want to reset both name and age
    // THIS IS FOR TRANSPARENCY. You don't need to code for name and age
    // it will assume the values in default..
    // =;   //which means the current state.
    // this.age = this.age;

    // do reset isAdmin and hits(suppose this.state.hits is 100 now)

    isAdmin = false;
    hits = 0;
  }// resetSelectively..


/* now from any function i can just call */
myfunction() {
   * this function code..

}// myfunction..

resetValues() {

//finally you can reset the values in constructor selectively at any point of the class..


How to write LDAP query to test if user is member of a group?

I would add one more thing to Marc's answer: The memberOf attribute can't contain wildcards, so you can't say something like "memberof=CN=SPS*", and expect it to find all groups that start with "SPS".

How to make Regular expression into non-greedy?

I believe it would be like this


the g at the end means global, so it doesn't stop at the first match.

How do you close/hide the Android soft keyboard using Java?

this is Working..

Just Pass your current activity instance in the function

 public void isKeyBoardShow(Activity activity) {
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
    if (imm.isActive()) {
        imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0); // hide
    } else {
        imm.toggleSoftInput(0, InputMethodManager.HIDE_IMPLICIT_ONLY); // show

Change background of LinearLayout in Android

u just used attribute

  • android:background="#ColorCode" for colors

    if your image save in drawable folder then used :-

  • android:background="@drawable/ImageName" for image setting

How to convert file to base64 in JavaScript?

If you're after a promise-based solution, this is @Dmitri's code adapted for that:

function getBase64(file) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => resolve(reader.result);
    reader.onerror = error => reject(error);

var file = document.querySelector('#files > input[type="file"]').files[0];
  data => console.log(data)

How do you fadeIn and animate at the same time?

$('.tooltip').animate({ opacity: 1, top: "-10px" }, 'slow');

However, this doesn't appear to work on display: none elements (as fadeIn does). So, you might need to put this beforehand:

$('.tooltip').css('display', 'block');
$('.tooltip').animate({ opacity: 0 }, 0);

Show datalist labels but submit the actual value

Note that datalist is not the same as a select. It allows users to enter a custom value that is not in the list, and it would be impossible to fetch an alternate value for such input without defining it first.

Possible ways to handle user input are to submit the entered value as is, submit a blank value, or prevent submitting. This answer handles only the first two options.

If you want to disallow user input entirely, maybe select would be a better choice.

To show only the text value of the option in the dropdown, we use the inner text for it and leave out the value attribute. The actual value that we want to send along is stored in a custom data-value attribute:

To submit this data-value we have to use an <input type="hidden">. In this case we leave out the name="answer" on the regular input and move it to the hidden copy.

<input list="suggestionList" id="answerInput">
<datalist id="suggestionList">
    <option data-value="42">The answer</option>
<input type="hidden" name="answer" id="answerInput-hidden">

This way, when the text in the original input changes we can use javascript to check if the text also present in the datalist and fetch its data-value. That value is inserted into the hidden input and submitted.

document.querySelector('input[list]').addEventListener('input', function(e) {
    var input =,
        list = input.getAttribute('list'),
        options = document.querySelectorAll('#' + list + ' option'),
        hiddenInput = document.getElementById(input.getAttribute('id') + '-hidden'),
        inputValue = input.value;

    hiddenInput.value = inputValue;

    for(var i = 0; i < options.length; i++) {
        var option = options[i];

        if(option.innerText === inputValue) {
            hiddenInput.value = option.getAttribute('data-value');

The id answer and answer-hidden on the regular and hidden input are needed for the script to know which input belongs to which hidden version. This way it's possible to have multiple inputs on the same page with one or more datalists providing suggestions.

Any user input is submitted as is. To submit an empty value when the user input is not present in the datalist, change hiddenInput.value = inputValue to hiddenInput.value = ""

Working jsFiddle examples: plain javascript and jQuery

Equivalent of typedef in C#

I think there is no typedef. You could only define a specific delegate type instead of the generic one in the GenericClass, i.e.

public delegate GenericHandler EventHandler<EventData>

This would make it shorter. But what about the following suggestion:

Use Visual Studio. This way, when you typed

gcInt.MyEvent += 

it already provides the complete event handler signature from Intellisense. Press TAB and it's there. Accept the generated handler name or change it, and then press TAB again to auto-generate the handler stub.

CORS header 'Access-Control-Allow-Origin' missing

Server side put this on top of .php:

 header('Access-Control-Allow-Origin: *');  

You can set specific domain restriction access:


Converting Chart.js canvas chart to image using .toDataUrl() results in blank image

First convert your Chart.js canvas to base64 string.

var url_base64 = document.getElementById('myChart').toDataURL('image/png');

Set it as a href attribute for anchor tag.

link.href = url_base64;

<a id='link' download='filename.png'>Save as Image</a>

How do you programmatically update query params in react-router?

    for react-router v4.3, 
 const addQuery = (key, value) => {
  let pathname = props.location.pathname; 
 // returns path: '/app/books'
  let searchParams = new URLSearchParams(; 
 // returns the existing query string: '?type=fiction&author=fahid'
  searchParams.set(key, value);
           pathname: pathname,
           search: searchParams.toString()

  const removeQuery = (key) => {
  let pathname = props.location.pathname; 
 // returns path: '/app/books'
  let searchParams = new URLSearchParams(; 
 // returns the existing query string: '?type=fiction&author=fahid'
           pathname: pathname,
           search: searchParams.toString()


 function SomeComponent({ location }) {
   return <div>
     <button onClick={ () => addQuery('book', 'react')}>search react books</button>
     <button onClick={ () => removeQuery('book')}>remove search</button>

 //  To know more on URLSearchParams from 

 var paramsString = "q=URLUtils.searchParams&topic=api";
 var searchParams = new URLSearchParams(paramsString);

 //Iterate the search parameters.
 for (let p of searchParams) {

 searchParams.has("topic") === true; // true
 searchParams.get("topic") === "api"; // true
 searchParams.getAll("topic"); // ["api"]
 searchParams.get("foo") === null; // true
 searchParams.append("topic", "webdev");
 searchParams.toString(); // "q=URLUtils.searchParams&topic=api&topic=webdev"
 searchParams.set("topic", "More webdev");
 searchParams.toString(); // "q=URLUtils.searchParams&topic=More+webdev"
 searchParams.toString(); // "q=URLUtils.searchParams"


Facebook Graph API : get larger pictures in one request

I got this error when I made a request with picture.type(full_picture):

"(#100) For field 'picture': type must be one of the following values: small, normal, album, large, square"

When I make the request with picture.type(album) and picture.type(square), responses me with an image 50x50 pixel size.

When I make the request with picture.type(large), responses me with an image 200x200 pixel size.

When I make the request with picture.width(800), responses me with an image 477x477 pixel size.

with picture.width(250), responses 320x320.

with picture.width(50), responses 50x50.

with picture.width(100), responses 100x100.

with picture.width(150), responses 160x160.

I think that facebook gives the images which resized variously when the user first add that photo.

What I see here the API for requesting user Image does not support resizing the image requested. It gives the nearest size of image, I think.

macro - open all files in a folder

You can use Len(StrFile) > 0 in loop check statement !

Sub openMyfile()

    Dim Source As String
    Dim StrFile As String

    'do not forget last backslash in source directory.
    Source = "E:\Planning\03\"
    StrFile = Dir(Source)

    Do While Len(StrFile) > 0                        
        Workbooks.Open Filename:=Source & StrFile
        StrFile = Dir()
End Sub

jQuery onclick toggle class name

It can even be made dependent to another attribute changes. like this:

$('.classA').toggleClass('classB', $('input').prop('disabled'));

In this case, classB are added each time the input is disabled

Installing Apache Maven Plugin for Eclipse

Eclipse > Help > Eclipse Marketplace...

Search for m2e

Install Maven Integration for Eclipse (Juno and newer). [It works for Indigo also]

Best Python IDE on Linux

I haven't played around with it much but eclipse/pydev feels nice.

HTTP Error 401.2 - Unauthorized You are not authorized to view this page due to invalid authentication headers

Make sure Anonymous access is enabled on IIS -> Authentication.

But also right click on it, then click on Edit, and choose a domain\username and password. (With access to the physical folder of the application).

Program to find largest and smallest among 5 numbers without using array

For example 5 consecutive numbers

int largestNumber;
int smallestNumber;
int number;
largestNumber = number;
smallestNumber = number;
for (i=0 ; i<5; i++)
   if (number > largestNumber) 
     largest = number;
   if (numbers < smallestNumber) 
     smallestNumber= number;

You can't specify target table for update in FROM clause

You can make this in three steps:

FROM pers p
  OR gehalt < (
      gehalt * 1.05
    FROM pers MA
    WHERE MA.chefID = p.chefID


SET P.gehalt = P.gehalt * 1.05
IN (
  FROM test2


UPDATE Pers P, (
  FROM pers p
   chefID IS NOT NULL 
   OR gehalt < (
       gehalt * 1.05
     FROM pers MA
     WHERE MA.chefID = p.chefID
) t
SET P.gehalt = P.gehalt * 1.05
WHERE p.PersId = t.PersId

AngularJS routing without the hash '#'

In fact you need the # (hashtag) for non HTML5 browsers.

Otherwise they will just do an HTTP call to the server at the mentioned href. The # is an old browser shortcircuit which doesn't fire the request, which allows many js frameworks to build their own clientside rerouting on top of that.

You can use $locationProvider.html5Mode(true) to tell angular to use HTML5 strategy if available.

Here the list of browser that support HTML5 strategy:

HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

        <ColumnDefinition Width="*" MaxWidth="200"/>

    <TextBox Background="Azure" Text="Hello" />

How to write a cron that will run a script every day at midnight?

Quick guide to setup a cron job

Create a new text file, example: mycronjobs.txt

For each daily job (00:00, 03:45), save the schedule lines in mycronjobs.txt

00 00 * * * ruby path/to/your/script.rb
45 03 * * * path/to/your/

Send the jobs to cron (everytime you run this, cron deletes what has been stored and updates with the new information in mycronjobs.txt)

crontab mycronjobs.txt

Extra Useful Information

See current cron jobs

crontab -l

Remove all cron jobs

crontab -r

LINQ Group By into a Dictionary Object

For @atari2600, this is what the answer would look like using ToLookup in lambda syntax:

var x = listOfCustomObjects
    .GroupBy(o => o.PropertyName)
    .ToLookup(customObject => customObject);

Basically, it takes the IGrouping and materializes it for you into a dictionary of lists, with the values of PropertyName as the key.

Android AlertDialog Single Button

Its very simple

new AlertDialog.Builder(this).setView(input).setPositiveButton("ENTER",            
                        new DialogInterface.OnClickListener()                      
                        {   public void onClick(DialogInterface di,int id)     

In case you wish to read the full program see here: Program to take input from user using dialog and output to screen

How to delete files older than X hours

For SunOS 5.10

 Example 6 Selecting a File Using 24-hour Mode

 The descriptions of -atime, -ctime, and -mtime use the  ter-
 minology n ``24-hour periods''. For example, a file accessed
 at 23:59 is selected by:

   example% find . -atime -1 -print

 at 00:01 the next day (less than 24 hours  later,  not  more
 than one day ago). The midnight boundary between days has no
 effect on the 24-hour calculation.

How to clear radio button in Javascript?

This should work. Make sure each button has a unique ID. (Replace Choose_Yes and Choose_No with the IDs of your two radio buttons)

document.getElementById("Choose_Yes").checked = false;
document.getElementById("Choose_No").checked = false;

An example of how the radio buttons should be named:

<input type="radio" name="Choose" id="Choose_Yes" value="1" /> Yes
<input type="radio" name="Choose" id="Choose_No" value="2" /> No

Multiple inheritance for an anonymous class

An anonymous class usually implements an interface:

new Runnable() { // implements Runnable!
   public void run() {}

JFrame.addWindowListener( new WindowAdapter() { // extends  class
} );

If you mean whether you can implement 2 or more interfaces, than I think that's not possible. You can then make a private interface which combines the two. Though I cannot easily imagine why you would want an anonymous class to have that:

 public class MyClass {
   private interface MyInterface extends Runnable, WindowListener { 

   Runnable r = new MyInterface() {
    // your anonymous class which implements 2 interaces


What does map(&:name) mean in Ruby?

map(&:name) takes an enumerable object (tags in your case) and runs the name method for each element/tag, outputting each returned value from the method.

It is a shorthand for { |element| }

which returns the array of element(tag) names

How to execute only one test spec with angular-cli

Each of your .spec.ts file have all its tests grouped in describe block like this:

describe('SomeComponent', () => {...}

You can easily run just this single block, by prefixing the describe function name with f:

fdescribe('SomeComponent', () => {...}

If you have such function, no other describe blocks will run. Btw. you can do similar thing with it => fit and there is also a "blacklist" version - x. So:

  • fdescribe and fit causes only functions marked this way to run
  • xdescribe and xit causes all but functions marked this way to run

Displaying output of a remote command with Ansible

Prints pubkey and avoid the changed status by adding changed_when: False to cat task:

- name: Generate SSH keys for vagrant user   
  user: name=vagrant generate_ssh_key=yes ssh_key_bits=2048

- name: Check SSH public key   
  command: /bin/cat $home_directory/.ssh/
  register: cat
  changed_when: False

- name: Print SSH public key
  debug: var=cat.stdout

- name: Wait for user to copy SSH public key   
  pause: prompt="Please add the SSH public key above to your GitHub account"

Calculate rolling / moving average in C++

Incrementing on @Nilesh's answer (credit goes to him), you can:

  • keep track of the sum, no need to divide and then multiply every time, generating error
  • avoid if conditions using % operator

This is UNTESTED sample code to show the idea, it could also be wrapped into a class:

const unsigned int size=10; // ten elements buffer

unsigned int counterPosition=0;
unsigned int counterNum=0;

int buffer[size];
long sum=0;

void reset() {
    for(int i=0;i<size;i++) {

float addValue(int value) {
    unsigned  int oldPos = ((counterPosition + 1) % size);

    buffer[counterPosition] = value;
    sum = (sum - buffer[oldPos] + value); 

    counterPosition=(counterPosition+1) % size;
    if(counterNum<size) counterNum++;

    return ((float)sum)/(float)counterNum;

float removeValue() {
    unsigned  int oldPos =((counterPosition + 1) % size);

    buffer[counterPosition] = 0;
    sum = (sum - buffer[oldPos]); 

    if(counterNum>1) { // leave one last item at the end, forever
        counterPosition=(counterPosition+1) % size;
        counterNum--; // here the two counters are different
    return ((float)sum)/(float)counterNum;

It should be noted that, if the buffer is reset to all zeroes, this method works fine while receiving the first values in as - buffer[oldPos] is zero and counter grows. First output is the first number received. Second output is the average of only the first two, and so on, fading in the values while they arrive until size items are reached.

It is also worth considering that this method, like any other for rolling average, is asymmetrical, if you stop at the end of the input array, because the same fading does not happen at the end (it can happen after the end of data, with the right calculations).

That is correct. The rolling average of 100 elements with a buffer of 10 gives different results: 10 fading in, 90 perfectly rolling 10 elements, and finally 10 fading out, giving a total of 110 results for 100 numbers fed in! It's your choice to decide which ones to show (and if it's better going the straight way, old to recent, or backwards, recent to old).

To fade out correctly after the end, you can go on adding zeroes one by one and reducing the count of items by one every time until you have reached size elements (still keeping track of correct position of old values).

Usage is like this:

int avg=0;

avg=addValue(2); // Rpeat for 100 times
avg=addValue(3); // Use avg value


avg=addValue(12); // last numer, 100th input 

// If you want to fade out repeat 10 times after the end of data:

avg=removeValue(); // Rpeat for last 10 times after data has finished
avg=removeValue(); // Use avg value

How do I vertical center text next to an image in html/css?

One basic way that comes to mind would be to put the item into a table and have two cells, one with the text, the other with the image, and use style="valign:center" with the tags.

How to convert the ^M linebreak to 'normal' linebreak in a file opened in vim?

sed s/^M//g file1.txt > file2.txt

where ^M is typed by simultaneously pressing the 3 keys, ctrl + v + m

Python: One Try Multiple Except

Yes, it is possible.

except FirstException:

except SecondException:

except (ThirdException, FourthException, FifthException) as e:

except Exception:


The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that the parentheses for the triple exception case are needed in python 3. This page has more info: Catch multiple exceptions in one line (except block)

How do I get the function name inside a function in PHP?

The accurate way is to use the __FUNCTION__ predefined magic constant.


class Test {
    function MethodA(){
        echo __FUNCTION__;

Result: MethodA.

Check if value exists in dataTable?

DataRow rw = table.AsEnumerable().FirstOrDefault(tt => tt.Field<string>("Author") == "Name");
if (rw != null)
// row exists

add to your using clause :

using System.Linq;

and add :


to references.

Align text in JLabel to the right

JLabel label = new JLabel("fax", SwingConstants.RIGHT);

sweet-alert display HTML code in text

A feature to allow HTML for title and text parameters has been added with a recent merge into the master branch on GitHub

Simply use JSON configuration and set 'html' to true, eg:

swal({ html:true, title:'<i>TITLE</i>', text:'<b>TEXT</b>'});

This was merged less than a week ago and is hinted at in the (html is set to false in one of the examples although not explicitly described) however it is not yet documented on the marketing page

SQL Server SELECT INTO @variable?

    CustomerId = @CustomerId"

Which means creating a new @tempCustomer tablevariable and inserting data FROM Customer. You had already declared it above so no need of again declaring. Better to go with

INSERT INTO @tempCustomer SELECT * FROM Customer

Formatting a number with leading zeros in PHP

Given that the value is in $value:

  • To echo it:

    printf("%08d", $value);

  • To get it:

    $formatted_value = sprintf("%08d", $value);

That should do the trick

What's the best way to iterate an Android Cursor?

The Do/While solution is more elegant, but if you do use just the While solution posted above, without the moveToPosition(-1) you will miss the first element (at least on the Contact query).

I suggest:

if (cursor.getCount() > 0) {
    while (cursor.moveToNext()) {
          <do stuff>

Is it possible to get element from HashMap by its position?

By default, java LinkedHasMap does not support for getting value by position. So I suggest go with customized IndexedLinkedHashMap

public class IndexedLinkedHashMap<K, V> extends LinkedHashMap<K, V> {

    private ArrayList<K> keysList = new ArrayList<>();

    public void add(K key, V val) {
        super.put(key, val);

    public void update(K key, V val) {
        super.put(key, val);

    public void removeItemByKey(K key) {

    public void removeItemByIndex(int index) {

    public V getItemByIndex(int i) {
        return (V) super.get(keysList.get(i));

    public int getIndexByKey(K key) {
        return keysList.indexOf(key);

Then you can use this customized LinkedHasMap as

IndexedLinkedHashMap<String,UserModel> indexedLinkedHashMap=new IndexedLinkedHashMap<>();

TO add Values


To getValue by index


Operation is not valid due to the current state of the object, when I select a dropdown list


Issue happens because Microsoft Security Update MS11-100 limits number of keys in Forms collection during HTTP POST request. To alleviate this problem you need to increase that number.

This can be done in your application Web.Config in the <appSettings> section (create the section directly under <configuration> if it doesn’t exist). Add 2 lines similar to the lines below to the section:

<add key="aspnet:MaxHttpCollectionKeys" value="2000" />
<add key="aspnet:MaxJsonDeserializerMembers" value="2000" />

The above example set the limit to 2000 keys. This will lift the limitation and the error should go away.

Firefox Add-on RESTclient - How to input POST parameters?

Request header needs to be set as per below image.add request header

request body can be passed as json string in text area. enter image description here

SQL User Defined Function Within Select

If it's a table-value function (returns a table set) you simply join it as a Table

this function generates one column table with all the values from passed comma-separated list

SELECT * FROM dbo.udf_generate_inlist_to_table('1,2,3,4')

Could not load dynamic library 'cudart64_101.dll' on tensorflow CPU-only installation

In my case the tensorflow install was looking for cudart64_101.dll

enter image description here

The 101 part of cudart64_101 is the Cuda version - here 101 = 10.1

I had downloaded 11.x, so the version of cudart64 on my system was cudart64_110.dll

enter image description here

This is the wrong file!! cudart64_101.dll ? cudart64_110.dll


Download Cuda 10.1 from

Install (mine crashes with NSight Visual Studio Integration, so I switched that off)

enter image description here

When the install has finished you should have a Cuda 10.1 folder, and in the bin the dll the system was complaining about being missing

enter image description here

Check that the path to the 10.1 bin folder is registered as a system environmental variable, so it will be checked when loading the library

enter image description here

You may need a reboot if the path is not picked up by the system straight away

enter image description here

jQuery: read text file from file system

this one is working

        $.get('1.txt', function(data) {
            //var fileDom = $(data);

            var lines = data.split("\n");

            $.each(lines, function(n, elem) {
                $('#myContainer').append('<div>' + elem + '</div>');

How to delete or change directory of a cloned git repository on a local computer

You can just delete that directory that you cloned the repo into, and re-clone it wherever you'd like.

Swift apply .uppercaseString to only the first letter of a string

Swift 3 (xcode 8.3.3)

Uppercase all first characters of string

let str = "your string"
let capStr = str.capitalized

//Your String

Uppercase all characters

let str = "your string"
let upStr = str.uppercased()


Uppercase only first character of string

 var str = "your string"
 let capStr = String(str.characters.prefix(1)).uppercased() + String(str.characters.dropFirst())

//Your string

How to conditionally take action if FINDSTR fails to find a string

I tried to get this working using FINDSTR, but for some reason my "debugging" command always output an error level of 0:


My workaround is to use Grep from Cygwin, which outputs the right errorlevel (it will give an errorlevel greater than 0) if a string is not found:

dir c:\*.tib >out 2>>&1
grep "1 File(s)" out
IF %ERRORLEVEL% NEQ 0 "Run other commands" ELSE "Run Errorlevel 0 commands"

Cygwin's grep will also output errorlevel 2 if the file is not found. Here's the hash from my version:

C:\temp\temp>grep --version grep (GNU grep) 2.4.2

C:\cygwin64\bin>md5sum grep.exe c0a50e9c731955628ab66235d10cea23 *grep.exe

C:\cygwin64\bin>sha1sum grep.exe ff43a335bbec71cfe99ce8d5cb4e7c1ecdb3db5c *grep.exe

Android get image from gallery into ImageView

Simple pass Intent first:

Intent i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_LOAD_IMAGE);

And you will get picture path on your onActivityResult:

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };
            Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            ImageView imageView = (ImageView) findViewById(;

for full source code here

Git merge is not possible because I have unmerged files

Another potential cause for this (Intellij was involved in my case, not sure that mattered though): trying to merge in changes from a main branch into a branch off of a feature branch.

In other words, merging "main" into "current" in the following arrangement:


I resolved all conflicts and GiT reported unmerged files and I was stuck until I merged from main into feature, then feature into current.

Run a Docker image as a container

For those who had the same problem as well, but encountered an error like

rpc error: code = 2 desc = oci runtime error: exec failed: container_linux.go:247: starting container process caused "exec: \"bash\": executable file not found in $PATH"

I added an entry point that was worked for me:

docker run -it --entrypoint /bin/sh for the images without Bash.

Example (from the approved example):

run -it --entrypoint /bin/sh ubuntu:12.04


makefile execute another target

Actually you are right: it runs another instance of make. A possible solution would be:

.PHONY : clearscr fresh clean all

all :
    compile executable

clean :
    rm -f *.o $(EXEC)

fresh : clean clearscr all


By calling make fresh you get first the clean target, then the clearscreen which runs clear and finally all which does the job.

EDIT Aug 4

What happens in the case of parallel builds with make’s -j option? There's a way of fixing the order. From the make manual, section 4.2:

Occasionally, however, you have a situation where you want to impose a specific ordering on the rules to be invoked without forcing the target to be updated if one of those rules is executed. In that case, you want to define order-only prerequisites. Order-only prerequisites can be specified by placing a pipe symbol (|) in the prerequisites list: any prerequisites to the left of the pipe symbol are normal; any prerequisites to the right are order-only: targets : normal-prerequisites | order-only-prerequisites

The normal prerequisites section may of course be empty. Also, you may still declare multiple lines of prerequisites for the same target: they are appended appropriately. Note that if you declare the same file to be both a normal and an order-only prerequisite, the normal prerequisite takes precedence (since they are a strict superset of the behavior of an order-only prerequisite).

Hence the makefile becomes

.PHONY : clearscr fresh clean all

all :
    compile executable

clean :
    rm -f *.o $(EXEC)

fresh : | clean clearscr all


EDIT Dec 5

It is not a big deal to run more than one makefile instance since each command inside the task will be a sub-shell anyways. But you can have reusable methods using the call function.

log_success = (echo "\x1B[32m>> $1\x1B[39m")
log_error = (>&2 echo "\x1B[31m>> $1\x1B[39m" && exit 1)

  @[ "$(AWS_PROFILE)" ] || $(call log_error, "AWS_PROFILE not set!")
  command1  # this line will be a subshell
  command2  # this line will be another subshell
  @command3  # Use `@` to hide the command line
  $(call log_error, "It works, yey!")

  @[ "$(AWS_PROFILE)" ] || $(call log_error, "AWS_PROFILE not set!")
  $(call log_error, "Nuked!")

How to know when a web page was last updated?

Take a look at

You can find almost everything about the past of a website there.

Can two or more people edit an Excel document at the same time?

Unfortunately, the file must be locked for updates unless you're using Office 2010 and SharePoint 2010 together. This means that only one user per time can edit a file. The locking and version tracking capabilities of SharePoint are excellent, and this makes it a great tool for the type of collaboration you're talking about, but you would have to split documents into multiple files in order to extend the amount that could be edited at a time. For instance, we sometimes unmerge documents into technical, requirements, and financials sections so that the 3 experts required for the review can work concurrently. We then merge when everyone is finished.

Mapping list in Yaml to list of objects in Spring Boot

I had referenced this article and many others and did not find a clear cut concise response to help. I am offering my discovery, arrived at with some references from this thread, in the following:

Spring-Boot version: 1.3.5.RELEASE

Spring-Core version: 4.2.6.RELEASE

Dependency Management: Brixton.SR1

The following is the pertinent yaml excerpt:

      name: jira
      matchUrl: http://someJiraUrl
      name: bamboo
      matchUrl: http://someBambooUrl

I created a Tools.class:

@ConfigurationProperties(prefix = "tools")
public class Tools{
    private List<Tool> toolList = new ArrayList<>();
    public Tools(){
      //empty ctor

    public List<Tool> getToolList(){
        return toolList;

    public void setToolList(List<Tool> tools){
       this.toolList = tools;

I created a Tool.class:

public class Tool{
    private String name;
    private String matchUrl;

    public Tool(){
      //empty ctor

    public String getName(){
        return name;

    public void setName(String name){ name;
    public String getMatchUrl(){
        return matchUrl;

    public void setMatchUrl(String matchUrl){
       this.matchUrl= matchUrl;

    public String toString(){
        StringBuffer sb = new StringBuffer();
        String ls = System.lineSeparator();
        sb.append("name:  " + name);
        sb.append("matchUrl:  " + matchUrl);

I used this combination in another class through @Autowired

public class SomeOtherClass{

   private Logger logger = LoggerFactory.getLogger(SomeOtherClass.class);

   private Tools tools;

   /* excluded non-related code */

   private void init(){
       List<Tool>  toolList = tools.getToolList();
       if(toolList.size() > 0){
           for(Tool t: toolList){
 "*****-----     tool size is zero     -----*****");

   /* excluded non-related code */


And in my logs the name and matching url's were logged. This was developed on another machine and thus I had to retype all of the above so please forgive me in advance if I inadvertently mistyped.

I hope this consolidation comment is helpful to many and I thank the previous contributors to this thread!

Stop mouse event propagation

This solved my problem, from preventign that an event gets fired by a children:

  // what ever_x000D_
        <div (click)="doSmth()">_x000D_
            <div (click)="$event.stopPropagation()">_x000D_

Parsing a pcap file in python

You might want to start with scapy.

How do I autoindent in Netbeans?

Ctrl+Shift+F will do a format of all the code in the page.

How to switch activity without animation in Android?

You can create a style,

 <style name="noAnimTheme" parent="android:Theme">
   <item name="android:windowAnimationStyle">@null</item>

and set it as theme for your activity in the manifest:

   <activity android:name=".ui.ArticlesActivity" android:theme="@style/noAnimTheme">

You can also define a style to specify custom entry and exit animations.

How to allow http content within an iframe on a https site

Note: While this solution may have worked in some browsers when it was written in 2014, it no longer works. Navigating or redirecting to an HTTP URL in an iframe embedded in an HTTPS page is not permitted by modern browsers, even if the frame started out with an HTTPS URL.

The best solution I created is to simply use google as the ssl proxy...

Tested and works in firefox.

Other Methods:

  • Use a Third party such as (but it it really only good for well known http APIs).

  • Create your own redirect script on an https page you control (a simple javascript redirect on a relative linked page should do the trick. Something like: (you can use any langauge/method) That has a iframe linking to... Which has a simple js redirect script like...

    document.location.href ="";

  • Alternatively, you could add an RSS feed or write some reader/parser to read the http site and display it within your https site.

  • You could/should also recommend to the http site owner that they create an ssl connection. If for no other reason than it increases seo.

Unless you can get the http site owner to create an ssl certificate, the most secure and permanent solution would be to create an RSS feed grabing the content you need (presumably you are not actually 'doing' anything on the http site -that is to say not logging in to any system).

The real issue is that having http elements inside a https site represents a security issue. There are no completely kosher ways around this security risk so the above are just current work arounds.

Note, that you can disable this security measure in most browsers (yourself, not for others). Also note that these 'hacks' may become obsolete over time.

How to add number of days in postgresql datetime

This will give you the deadline :

select id,  
       created_at + interval '1' day * claim_window as deadline
from projects

Alternatively the function make_interval can be used:

select id,  
       created_at + make_interval(days => claim_window) as deadline
from projects

To get all projects where the deadline is over, use:

select *
from (
  select id, 
         created_at + interval '1' day * claim_window as deadline
  from projects
) t
where localtimestamp at time zone 'UTC' > deadline

Javascript "Not a Constructor" Exception while creating objects

Sometimes it is just how you export and import it. For this error message it could be, that the default keyword is missing.

export default SampleClass {}

Where you instantiate it:

import SampleClass from 'path/to/class';
let sampleClass = new SampleClass();

Option 2, with curly braces:

export SampleClass {}
import { SampleClass } from 'path/to/class';
let sampleClass = new SampleClass();

How to trigger a build only if changes happen on particular set of files

While this doesn't affect single jobs, you can use this script to ignore certain steps if the latest commit did not contain any changes:

 * Check a folder if changed in the latest commit.
 * Returns true if changed, or false if no changes.
def checkFolderForDiffs(path) {
    try {
        // git diff will return 1 for changes (failure) which is caught in catch, or
        // 0 meaning no changes 
        sh "git diff --quiet --exit-code HEAD~1..HEAD ${path}"
        return false
    } catch (err) {
        return true

if ( checkFolderForDiffs('api/') ) {
    //API folder changed, run steps here

Where is shared_ptr?

If your'e looking bor boost's shared_ptr, you could have easily found the answer by googling shared_ptr, following the links to the docs, and pulling up a complete working example such as this.

In any case, here is a minimalistic complete working example for you which I just hacked up:

#include <boost/shared_ptr.hpp>

struct MyGizmo
    int n_;

int main()
    boost::shared_ptr<MyGizmo> p(new MyGizmo);
    return 0;

In order for the #include to find the header, the libraries obviously need to be in the search path. In MSVC, you set this in Project Settings>Configuration Properties>C/C++>Additional Include Directories. In my case, this is set to C:\Program Files (x86)\boost\boost_1_42

Catch KeyError in Python

I dont think python has a catch :)

    connection = manager.connect("I2Cx")
except Exception, e:
    print e

How to set space between listView Items in Android

In order to give spacing between views inside a listView please use padding on your inflate views.

You can use android:paddingBottom="(number)dp" && android:paddingTop="(number)dp" on your view or views you're inflate inside your listview.

The divider solution is just a fix, because some day, when you'll want to use a divider color (right now it's transparent) you will see that the divider line is been stretched.

Python wildcard search in string

Use fnmatch:

import fnmatch
lst = ['this','is','just','a','test']
filtered = fnmatch.filter(lst, 'th?s')

If you want to allow _ as a wildcard, just replace all underscores with '?' (for one character) or * (for multiple characters).

If you want your users to use even more powerful filtering options, consider allowing them to use regular expressions.

How to delete columns that contain ONLY NAs?

Another option with Filter

Filter(function(x) !all(, df)

NOTE: Data from @Simon O'Hanlon's post.

How to declare a global variable in C++

Not sure if this is correct in any sense but this seems to work for me.

inline int someVar;

I don't have linking/multiple definition issues and it "just works"... ;- )

It's quite handy for "quick" tests... Try to avoid global vars tho, because every says so... ;- )

Entity Framework 6 Code first Default value

You can do it by manually edit code first migration:

public override void Up()
   AddColumn("dbo.Events", "Active", c => c.Boolean(nullable: false, defaultValue: true));

find difference between two text files with one item per line

You can use the comm command to compare two sorted files

comm -13 <(sort file1) <(sort file2)

How do I choose the URL for my Spring Boot webapp?

In Spring Boot 2 the property in e.g. is server.servlet.context-path=/myWebApp to set the context path.

Where does R store packages?

You do not want the '='

Use .libPaths("C:/R/library") in you file

And make sure you have correct " symbol (Shift-2)

Copy all values from fields in one class to another through reflection

  1. Without using BeanUtils or Apache Commons

  2. public static <T1 extends Object, T2 extends Object>  void copy(T1     
    origEntity, T2 destEntity) throws IllegalAccessException, NoSuchFieldException {
        Field[] fields = origEntity.getClass().getDeclaredFields();
        for (Field field : fields){
            origFields.set(destEntity, field.get(origEntity));

How to add class active on specific li on user click with jQuery

//Write a javascript method to bind click event of each "li" item

    function BindClickEvent()
    var selector = '.nav li';
    //Removes click event of each li
    $(selector ).unbind('click');
    //Add click event
    $(selector ).bind('click', function()


//first call this method when first time when page load

    $( document ).ready(function() {

//Call BindClickEvent method from server side

    protected void Page_Load(object sender, EventArgs e)
        ScriptManager.RegisterStartupScript(Page,GetType(), Guid.NewGuid().ToString(),"BindClickEvent();",true);

How can I check whether an array is null / empty?

I tested as below. Hope it helps.

Integer[] integers1 = new Integer[10];
        System.out.println(integers1.length); //it has length 10 but it is empty. It is not null array
        for (Integer integer : integers1) {
            System.out.println(integer); //prints all 0s

//But if I manually add 0 to any index, now even though array has all 0s elements
//still it is not empty
//        integers1[2] = 0;
        for (Integer integer : integers1) {
            System.out.println(integer); //Still it prints all 0s but it is not empty
            //but that manually added 0 is different

//Even we manually add 0, still we need to treat it as null. This is semantic logic.

        Integer[] integers2 = new Integer[20];
        integers2 = null; //array is nullified
//        integers2[3] = null; //If I had int[] -- because it is priitive -- then I can't write this line. 
        if (integers2 == null) {
            System.out.println("null Array");

Get file path of image on Android

Posting to Twitter needs the image's actual path on the device to be sent in the request to post. I was finding it mighty difficult to get the actual path and more often than not I would get the wrong path.

To counter that, once you have a Bitmap, I use that to get the URI from using the getImageUri(). Subsequently, I use the tempUri Uri instance to get the actual path as it is on the device.

This is production code and naturally tested. ;-)

protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
    if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
        Bitmap photo = (Bitmap) data.getExtras().get("data"); 

        Uri tempUri = getImageUri(getApplicationContext(), photo);

        File finalFile = new File(getRealPathFromURI(tempUri));


public Uri getImageUri(Context inContext, Bitmap inImage) {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
    String path = Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
    return Uri.parse(path);

public String getRealPathFromURI(Uri uri) {
    Cursor cursor = getContentResolver().query(uri, null, null, null, null); 
    int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); 
    return cursor.getString(idx); 

How does the stack work in assembly language?

You are correct that a stack is a data structure. Often, data structures (stacks included) you work with are abstract and exist as a representation in memory.

The stack you are working with in this case has a more material existence- it maps directly to real physical registers in the processor. As a data structure, stacks are FILO (first in, last out) structures that ensure data is removed in the reverse order it was entered. See the StackOverflow logo for a visual! ;)

You are working with the instruction stack. This is the stack of actual instructions you are feeding the processor.

Can't install any packages in Node.js using "npm install"

The repository is not down, it looks like they've changed how they host files (I guess they have restored some old code):

Now you have to add the /package-name/ before the -


There are 3 ways to solve it:

  • Use a complete mirror:
  • Use a public proxy:


  • Host a local proxy:

git clone
cd npm-quickfix
npm set registry http://localhost:8080/
node index.js

I'd personally go with number 3 and revert to npm set registry as soon as this get resolved.

Stay tuned here for more info:

How to send HTML-formatted email?

Setting isBodyHtml to true allows you to use HTML tags in the message body:

msg = new MailMessage("[email protected]",
                "[email protected]", "Message from PSSP System",
                "This email sent by the PSSP system<br />" +
                "<b>this is bold text!</b>");

msg.IsBodyHtml = true;

MySQL SELECT last few days?

SELECT DATEDIFF(NOW(),pickup_date) AS noofday 
FROM cir_order 
WHERE DATEDIFF(NOW(),pickup_date)>2;


FROM cir_order 
WHERE cir_order.`cir_date` >= DATE_ADD( CURDATE(), INTERVAL -10 DAY )

Java constant examples (Create a java file having only constants)

Neither one. Use final class for Constants declare them as public static final and static import all constants wherever necessary.

public final class Constants {

    private Constants() {
            // restrict instantiation

    public static final double PI = 3.14159;
    public static final double PLANCK_CONSTANT = 6.62606896e-34;

Usage :

import static Constants.PLANCK_CONSTANT;
import static Constants.PI;//import static Constants.*;

public class Calculations {

        public double getReducedPlanckConstant() {
                return PLANCK_CONSTANT / (2 * PI);

See wiki link :

Today`s date in an excel macro

Here's an example that puts the Now() value in column A.

Sub move()
    Dim i As Integer
    Dim sh1 As Worksheet
    Dim sh2 As Worksheet
    Dim nextRow As Long
    Dim copyRange As Range
    Dim destRange As Range

    Application.ScreenUpdating = False

        Set sh1 = ActiveWorkbook.Worksheets("Sheet1")
        Set sh2 = ActiveWorkbook.Worksheets("Sheet2")
        Set copyRange = sh1.Range("A1:A5")

        i = Application.WorksheetFunction.CountA(sh2.Range("B:B")) + 4

        Set destRange = sh2.Range("B" & i)

        destRange.Resize(1, copyRange.Rows.Count).Value = Application.Transpose(copyRange.Value)
        destRange.Offset(0, -1).Value = Format(Now(), "MMM-DD-YYYY")


    Application.ScreenUpdating = True

End Sub

There are better ways of getting the last row in column B than using a While loop, plenty of examples around here. Some are better than others but depend on what you're doing and what your worksheet structure looks like. I used one here which assumes that column B is ALL empty except the rows/records you're moving. If that's not the case, or if B1:B3 have some values in them, you'd need to modify or use another method. Or you could just use your loop, but I'd search for alternatives :)

Which keycode for escape key with jQuery

27 is the code for the escape key. :)

Remove android default action bar

I've noticed that if you set the theme in the AndroidManifest, it seems to get rid of that short time where you can see the action bar. So, try adding this to your manifest:


Just add it to your application tag to apply it app-wide.


You can try this:

  count(distinct tag) as tag_count,
  count(distinct (case when entryId > 0 then tag end)) as positive_tag_count

The first count(distinct...) is easy. The second one, looks somewhat complex, is actually the same as the first one, except that you use case...when clause. In the case...when clause, you filter only positive values. Zeros or negative values would be evaluated as null and won't be included in count.

One thing to note here is that this can be done by reading the table once. When it seems that you have to read the same table twice or more, it can actually be done by reading once, in most of the time. As a result, it will finish the task a lot faster with less I/O.

Draw text in OpenGL ES

Look at the "Sprite Text" sample in the GLSurfaceView samples.

Python - Passing a function into another function

Just pass it in like any other parameter:

def a(x):
    return "a(%s)" % (x,)

def b(f,x):
    return f(x)

print b(a,10)

how to show progress bar(circle) in an activity having a listview before loading the listview with data

Use This Within button on Click option or your needs:

final ProgressDialog progressDialog;
progressDialog = new ProgressDialog(getApplicationContext());
progressDialog.setMessage("Loading..."); // Setting Message
progressDialog.setTitle("ProgressDialog"); // Setting Title
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); // Progress Dialog Style Spinner; // Display Progress Dialog
new Thread(new Runnable() {
    public void run() {
        try {
        } catch (Exception e) {

Sublime Text 2: How do I change the color that the row number is highlighted?

The easy way: Pick an alternative Color Scheme:

Preferences > Color Scheme > ...pick one

The more complicated way: Edit the current color scheme file:

Preferences > Browse Packages > Color Scheme - Default > ... edit the Color Scheme file you are using:

Looking at the structure of the XML, drill down into dict > settings > settings > dict >

Look for the key (or add it if it's missing): lineHighlight. Add a string with an #RRGGBB or #RRGGBBAA format.

Changing plot scale by a factor in matplotlib

Instead of changing the ticks, why not change the units instead? Make a separate array X of x-values whose units are in nm. This way, when you plot the data it is already in the correct format! Just make sure you add a xlabel to indicate the units (which should always be done anyways).

from pylab import *

# Generate random test data in your range
N = 200
epsilon = 10**(-9.0)
X = epsilon*(50*random(N) + 1)
Y = random(N)

# X2 now has the "units" of nanometers by scaling X
X2 = (1/epsilon) * X


xlim(1, 50)


enter image description here

How to Navigate from one View Controller to another using Swift

If you don't want the back button to appear (which was my case, because I wanted to present after a user logged in) here is how to set the root of the nav controller:

let vc = self.storyboard?.instantiateViewControllerWithIdentifier("YourViewController") as! YourViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.presentViewController(navigationController, animated: true, completion: nil)

How to use passive FTP mode in Windows command prompt?

The Windows FTP command-line client (ftp.exe) does not support the passive mode, on any version of Windows. It makes it pretty useless nowadays due to ubiquitous firewalls and NATs.

Using the quote pasv won't help. It switches only the server to the passive mode, but not the client.

Use any thirdparty Windows FTP command-line client instead. Most other support the passive mode.

For example WinSCP defaults to the passive mode and there's a guide available for converting Windows FTP script to WinSCP script. If you are starting from the scratch, see the guide to automating file transfers to FTP using WinSCP. Also, WinSCP GUI can generate a script template for you.

(I'm the author of WinSCP)

Installing the Android USB Driver in Windows 7

Just download and install "Samsung Kies" from this link. and everything would work as required.

Before installing, uninstall the drivers you have installed for your device.


Two possible solutions:

  1. Try with the Google USB driver which comes with the SDK.
  2. Download and install the Samsung USB driver from this link as suggested by Mauricio Gracia Gutierrez

Ruby max integer

as @Jörg W Mittag pointed out: in jruby, fix num size is always 8 bytes long. This code snippet shows the truth:

fmax = ->{
  if RUBY_PLATFORM == 'java'
    2**63 - 1
    2**(0.size * 8 - 2) - 1

p fmax.class     # Fixnum

fmax = fmax + 1  

p fmax.class     #Bignum

How do I set the background color of Excel cells using VBA?

You can use either:

ActiveCell.Interior.ColorIndex = 28


ActiveCell.Interior.Color = RGB(255,0,0)

How to declare a type as nullable in TypeScript?

To be more C# like, define the Nullable type like this:

type Nullable<T> = T | null;

interface Employee{
   id: number;
   name: string;
   salary: Nullable<number>;


To make Nullable behave like a built in Typescript type, define it in a global.d.ts definition file in the root source folder. This path worked for me: /src/global.d.ts

C++: How to round a double to an int?

#include <iostream>
#include <cmath>
using namespace std;

int main()
    double x=54.999999999999943157;
    int y=ceil(x);//The ceil() function returns the smallest integer no less than x
    return 0;

Read contents of a local file into a variable in Rails

I think you should consider using IO.binread("/path/to/file") if you have a recent ruby interpreter (i.e. >= 1.9.2)

You could find IO class documentation here

Should I use PATCH or PUT in my REST API?

I would recommend using PATCH, because your resource 'group' has many properties but in this case, you are updating only the activation field(partial modification)

according to the RFC5789 (

The existing HTTP PUT method only allows a complete replacement of a document. This proposal adds a new HTTP method, PATCH, to modify an existing HTTP resource.

Also, in more details,

The difference between the PUT and PATCH requests is reflected in the way the server processes the enclosed entity to modify the resource
identified by the Request-URI. In a PUT request, the enclosed entity is considered to be a modified version of the resource stored on the
origin server, and the client is requesting that the stored version
be replaced. With PATCH, however, the enclosed entity contains a set of instructions describing how a resource currently residing on the
origin server should be modified to produce a new version. The PATCH method affects the resource identified by the Request-URI, and it
also MAY have side effects on other resources; i.e., new resources
may be created, or existing ones modified, by the application of a

PATCH is neither safe nor idempotent as defined by [RFC2616], Section 9.1.

Clients need to choose when to use PATCH rather than PUT. For
example, if the patch document size is larger than the size of the
new resource data that would be used in a PUT, then it might make
sense to use PUT instead of PATCH. A comparison to POST is even more difficult, because POST is used in widely varying ways and can
encompass PUT and PATCH-like operations if the server chooses. If
the operation does not modify the resource identified by the Request- URI in a predictable way, POST should be considered instead of PATCH
or PUT.

The response code for PATCH is

The 204 response code is used because the response does not carry a message body (which a response with the 200 code would have). Note that other success codes could be used as well.

also refer t

Caveat: An API implementing PATCH must patch atomically. It MUST not be possible that resources are half-patched when requested by a GET.

How can I use ":" as an AWK field separator?

If you want to do it programatically, you can use the FS variable:

echo "1: " | awk 'BEGIN { FS=":" } /1/ { print $1 }'

Note that if you change it in the main loop rather than the BEGIN loop, it takes affect for the next line read in, since the current line has already been split.

How to find the minimum value of a column in R?

df <- read.table(text = 
             "X  Y
             1  2  3
             2  4  5
             3  6  7
             4  8  9
             5 10 11",
             header = TRUE)

y_min <- min(df[,"Y"])

# Corresponding X value
x_val_associated <- df[df$Y == y_min, "X"]


First, you find the Y min using the min function on the "Y" column only. Notice the returned result is just an integer value. Then, to find the associated X value, you can subset the data.frame to only the rows where the minimum Y value is located and extract just the "X" column.

You now have two integer values for X and Y where Y is the min.

How to upload images into MySQL database using PHP code

This is the perfect code for uploading and displaying image through MySQL database.

<form method="post" enctype="multipart/form-data">
<input type="file" name="image"/>
<input type="submit" name="submit" value="Upload"/>
        echo " error ";
        $image = $_FILES['image']['tmp_name'];
        $image = addslashes(file_get_contents($image));
    function saveimage($image)
        $qry="insert into tablename (name) values ('$image')";
            echo " <br/>Image uploaded.";
            echo " error ";

Is there a way to have printf() properly print out an array (of floats, say)?

You need to go for a loop:

for (int i = 0; i < sizeof(foo) / sizeof(float); ++i)
   printf("%f", foo[i]);

How to scale an Image in ImageView to keep the aspect ratio

Yo don't need any java code. You just have to :

android:scaleType="centerCrop" />

The key is in the match parent for width and height

IFRAMEs and the Safari on the iPad, how can the user scroll the content?

This is what I did to get iframe scrolling to work on iPad. Note that this solution only works if you control the html that is displayed inside the iframe.

It actually turns off the default iframe scrolling, and instead causes the body tag inside the iframe to scroll.


<!DOCTYPE html>
<style type="text/css">
#container {
    position: absolute;
    top: 50px;
    left: 50px;
    width: 400px;
    height: 300px;
    overflow: hidden;
#iframe {
    width: 400px;
    height: 300px;

    <div id="container">
        <iframe src="test.html" id="iframe" scrolling="no"></iframe>



<!DOCTYPE html>
<style type="text/css">
html { 
    overflow: auto; 
    -webkit-overflow-scrolling: touch; 
body {
    height: 100%;
    overflow: auto; 
    -webkit-overflow-scrolling: touch;
    margin: 0;
    padding: 8px;

The same could probably be accomplished using jQuery if you prefer:

    "height": "100%",
    "overflow": "auto", 
    "-webkit-overflow-scrolling": "touch"

I used this solution to get TinyMCE (wordpress editor) to scroll properly on the iPad.

How to create a session using JavaScript?

You can use sessionStorage it is similar to localStorage but sessionStorage gets clear when the page session ends while localStorage has no expiration set.


Django: Calling .update() on a single model instance retrieved by .get()?

With the advent of Django 1.7, there is now a new update_or_create QuerySet method, which should do exactly what you want. Just be careful of potential race conditions if uniqueness is not enforced at the database level.

Example from the documentation:

obj, created = Person.objects.update_or_create(
    first_name='John', last_name='Lennon',
    defaults={'first_name': 'Bob'},

The update_or_create method tries to fetch an object from database based on the given kwargs. If a match is found, it updates the fields passed in the defaults dictionary.

Pre-Django 1.7:

Change the model field values as appropriate, then call .save() to persist the changes:

    obj = Model.objects.get(field=value)
    obj.field = new_value
except Model.DoesNotExist:
    obj = Model.objects.create(field=new_value)
# do something else with obj if need be


In my case I was using a third party library (i.e. vendor) and the library comes with a sample app which I already had install on my device. So that sample app was now conflicting each time I try to install my own app implementing the library. So I just uninstalled the vendor's sample app and it works afterwards.

Get unique values from a list in python

As a bonus, Counter is a simple way to get both the unique values and the count for each value:

from collections import Counter
l = [u'nowplaying', u'PBS', u'PBS', u'nowplaying', u'job', u'debate', u'thenandnow']
c = Counter(l)

How to deal with SettingWithCopyWarning in Pandas

Pandas dataframe copy warning

When you go and do something like this:

quote_df = quote_df.ix[:,[0,3,2,1,4,5,8,9,30,31]]

pandas.ix in this case returns a new, stand alone dataframe.

Any values you decide to change in this dataframe, will not change the original dataframe.

This is what pandas tries to warn you about.

Why .ix is a bad idea

The .ix object tries to do more than one thing, and for anyone who has read anything about clean code, this is a strong smell.

Given this dataframe:

df = pd.DataFrame({"a": [1,2,3,4], "b": [1,1,2,2]})

Two behaviors:

dfcopy = df.ix[:,["a"]]
dfcopy.a.ix[0] = 2

Behavior one: dfcopy is now a stand alone dataframe. Changing it will not change df

df.ix[0, "a"] = 3

Behavior two: This changes the original dataframe.

Use .loc instead

The pandas developers recognized that the .ix object was quite smelly[speculatively] and thus created two new objects which helps in the accession and assignment of data. (The other being .iloc)

.loc is faster, because it does not try to create a copy of the data.

.loc is meant to modify your existing dataframe inplace, which is more memory efficient.

.loc is predictable, it has one behavior.

The solution

What you are doing in your code example is loading a big file with lots of columns, then modifying it to be smaller.

The pd.read_csv function can help you out with a lot of this and also make the loading of the file a lot faster.

So instead of doing this

quote_df = pd.read_csv(StringIO(str_of_all), sep=',', names=list('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefg')) #dtype={'A': object, 'B': object, 'C': np.float64}
quote_df.rename(columns={'A':'STK', 'B':'TOpen', 'C':'TPCLOSE', 'D':'TPrice', 'E':'THigh', 'F':'TLow', 'I':'TVol', 'J':'TAmt', 'e':'TDate', 'f':'TTime'}, inplace=True)
quote_df = quote_df.ix[:,[0,3,2,1,4,5,8,9,30,31]]

Do this

columns = ['STK', 'TPrice', 'TPCLOSE', 'TOpen', 'THigh', 'TLow', 'TVol', 'TAmt', 'TDate', 'TTime']
df = pd.read_csv(StringIO(str_of_all), sep=',', usecols=[0,3,2,1,4,5,8,9,30,31])
df.columns = columns

This will only read the columns you are interested in, and name them properly. No need for using the evil .ix object to do magical stuff.

ng-repeat: access key and value for each object in array of objects

seems like in Angular 1.3.12 you do not need the inner ng-repeat anymore, the outer loop returns the values of the collection is a single map entry

How to convert an Image to base64 string in java?

this did it for me. you can vary the options for the output format to Base64.Default whatsoever.

// encode base64 from image
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] b = baos.toByteArray();
encodedString = Base64.encodeToString(b, Base64.URL_SAFE | Base64.NO_WRAP);

How to select the comparison of two columns as one column in Oracle

I stopped using DECODE several years ago because it is non-portable. Also, it is less flexible and less readable than a CASE/WHEN.

However, there is one neat "trick" you can do with decode because of how it deals with NULL. In decode, NULL is equal to NULL. That can be exploited to tell whether two columns are different as below.

select a, b, decode(a, b, 'true', 'false') as same
  from t;

     A       B  SAME
------  ------  -----
     1       1  true
     1       0  false
     1          false
  null    null  true  

How to create Password Field in Model Django

I thinks it is vary helpful way.

from django.db import models
class User(models.Model):
    user_name = models.CharField(max_length=100)
    password = models.CharField(max_length=32)

from django import forms
from Admin.models import *
class User_forms(forms.ModelForm):
    class Meta:
        model= User
       widgets = {
      'password': forms.PasswordInput()

How do I replace multiple spaces with a single space in C#?

Consolodating other answers, per Joel, and hopefully improving slightly as I go:

You can do this with Regex.Replace():

string s = Regex.Replace (
    "   1  2    4 5", 
    @"[ ]{2,}", 
    " "

Or with String.Split():

static class StringExtensions
    public static string Join(this IList<string> value, string separator)
        return string.Join(separator, value.ToArray());


string s = "     1  2    4 5".Split (
    " ".ToCharArray(), 
    ).Join (" ");

What characters can be used for up/down triangle (arrow without stem) for display in HTML?

?? These are U+25B2 (&#x25B2) and U+25BC (&#x25BC) respectively

Curly braces in string in PHP

I've also found it useful to access object attributes where the attribute names vary by some iterator. For example, I have used the pattern below for a set of time periods: hour, day, month.

$periods=array('hour', 'day', 'month');
foreach ($periods as $period)

This same pattern can also be used to access class methods. Just build up the method name in the same manner, using strings and string variables.

You could easily argue to just use an array for the value storage by period. If this application were PHP only, I would agree. I use this pattern when the class attributes map to fields in a database table. While it is possible to store arrays in a database using serialization, it is inefficient, and pointless if the individual fields must be indexed. I often add an array of the field names, keyed by the iterator, for the best of both worlds.

class timevalues
                             // Database table values:
    public $value_hour;      // maps to values.value_hour
    public $value_day;       // maps to values.value_day
    public $value_month;     // maps to values.value_month
    public $values=array();

    public function __construct()

How to handle change of checkbox using jQuery?

It seems to me removeProp is not working properly in Chrome : jsfiddle

        $('#badBut1').click(function () {
        if( $('#chk').prop('checked') )
            $('#chk').prop('checked', true);
    $('#But1').click(function () {
        if( $('#chk').prop('checked') )
            $('#chk').addClass('checked').prop('checked', true);

    $('#But2').click(function () {
        var chk1 = $('#chk').is(':checked');
        console.log("Value : " + chk1);

    $('#chk').on( 'change',function () {
    function checkit(moment) {
        var chk1 = $('#chk').is(':checked');
        console.log(moment+", value = " + chk1);

Vim multiline editing like in sublimetext?

There are several ways to accomplish that in Vim. I don't know which are most similar to Sublime Text's though.

The first one would be via multiline insert mode. Put your cursor to the second "a" in the first line, press Ctrl-V, select all lines, then press I, and put in a doublequote. Pressing <esc> will repeat the operation on every line.

The second one is via macros. Put the cursor on the first character, and start recording a macro with qa. Go the your right with llll, enter insert mode with a, put down a doublequote, exit insert mode, and go back to the beginning of your row with <home> (or equivalent). Press j to move down one row. Stop recording with q. And then replay the macro with @a. Several times.

Does any of the above approaches work for you?

'if' in prolog?

I found this helpful for using an if statement in a rule.

max(X,Y,Z) :-
    (  X =< Y
    -> Z = Y
    ;  Z = X

Thanks to

How to keep environment variables when using sudo

A simple wrapper function (or in-line for loop)

I came up with a unique solution because:

  • sudo -E "$@" was leaking variables that was causing problems for my command
  • sudo VAR1="$VAR1" ... VAR42="$VAR42" "$@" was long and ugly in my case


function sudo_exports(){
    eval sudo $(for x in $_EXPORTS; do printf '%q=%q ' "$x" "${!x}"; done;) "$@"

# create a test script to call as sudo
echo 'echo Forty-Two is $VAR42' >
chmod +x

export VAR42="The Answer to the Ultimate Question of Life, The Universe, and Everything."


# clean function style
sudo_exports ./

# or just use the content of the function
eval sudo $(for x in $_EXPORTS; do printf '%q=%q ' "$x" "${!x}"; done;) ./


$ ./
Forty-Two is The Answer to the Ultimate Question of Life, The Universe, and Everything.
Forty-Two is The Answer to the Ultimate Question of Life, The Universe, and Everything.


This is made possible by a feature of the bash builtin printf. The %q produces a shell quoted string. Unlike the parameter expansion in bash 4.4, this works in bash versions < 4.0

What is The Rule of Three?

Basically if you have a destructor (not the default destructor) it means that the class that you defined has some memory allocation. Suppose that the class is used outside by some client code or by you.

    MyClass x(a, b);
    MyClass y(c, d);
    x = y; // This is a shallow copy if assignment operator is not provided

If MyClass has only some primitive typed members a default assignment operator would work but if it has some pointer members and objects that do not have assignment operators the result would be unpredictable. Therefore we can say that if there is something to delete in destructor of a class, we might need a deep copy operator which means we should provide a copy constructor and assignment operator.

Function pointer as a member of a C struct

You can use also "void*" (void pointer) to send an address to the function.

typedef struct pstring_t {
    char * chars;
} PString;

int length(void* self) {
    return strlen(((PString*)self)->chars);

PString initializeString() {
    PString str;
    str.length = &length;
    return str;

int main()
    PString p = initializeString();

    p.chars = "Hello";

    printf("Length: %i\n", p.length(&p));

    return 0;


Length: 5

Convert boolean result into number/integer



let t=true;_x000D_
let f=false;_x000D_

What does the "More Columns than Column Names" error mean?

you have have strange characters in your heading # % -- or ,

Python: call a function from string name

You can use a dictionary too.

def install():
    print "In install"

methods = {'install': install}

method_name = 'install' # set by the command line options
if method_name in methods:
    methods[method_name]() # + argument list of course
    raise Exception("Method %s not implemented" % method_name)

Invoke native date picker from web-app on iOS/Android

Give Mobiscroll a try. The scroller style date and time picker was especially created for interaction on touch devices. It is pretty flexible, and easily customizable. It comes with iOS/Android themes.

The localhost page isn’t working localhost is currently unable to handle this request. HTTP ERROR 500

It maybe solve your problem, check your files access level

$ sudo chmod -R 777 /"your files location"

What causes imported Maven project in Eclipse to use Java 1.5 instead of Java 1.6 by default and how can I ensure it doesn't?

I wanted to add something to the answer already provided. maven-compiler-plugin by default will compile your project using Java 1.5 which is where m2e get's its information.

That's why you have to explicitly declare the maven-compiler-plugin in your project with something other then 1.5. Your effective pom.xml will implicitly use the default set in the maven-compiler-plugin pom.xml.

How to set proper codeigniter base url?

application > config > config.php

search for $config['base_url'] and put your site like "//" (skip protocol)

 $config['base_url'] = "//";

This works for me.

Intercept and override HTTP requests from WebView

This may helps:

public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
    String url = request.getUrl().toString();
    WebResourceResponse response = super.shouldInterceptRequest(view, request);
    // load native js
    if (url != null && url.contains(INJECTION_TOKEN/* scheme define */)) {

        response = new WebResourceResponse(
                loadJsInputStream(url, JsCache.getJsFilePath(path) /* InputStream */));
    return response;

How do I get next month date from today's date and insert it in my database?

$nextm = date('m', strtotime('+1 month', strtotime(date('Y-m-01'))));

delete a column with awk or sed

With GNU awk for inplace editing, \s/\S, and gensub() to delete

1) the FIRST field:

awk -i inplace '{sub(/^\S+\s*/,"")}1' file


awk -i inplace '{$0=gensub(/^\S+\s*/,"",1)}1' file

2) the LAST field:

awk -i inplace '{sub(/\s*\S+$/,"")}1' file


awk -i inplace '{$0=gensub(/\s*\S+$/,"",1)}1' file

3) the Nth field where N=3:

awk -i inplace '{$0=gensub(/\s*\S+/,"",3)}1' file

Without GNU awk you need a match()+substr() combo or multiple sub()s + vars to remove a middle field. See also Print all but the first three columns.

Passing parameter using onclick or a click binding with KnockoutJS

Use a binding, like in this example:

<a href="#new-search" data-bind="click:SearchManager.bind($data,'1')">
  Search Manager
var ViewModelStructure = function () {
    var self = this;
    this.SearchManager = function (search) {

Is there a way to use shell_exec without waiting for the command to complete?

You can also give your output back to the client instantly and continue processing your PHP code afterwards.

This is the method I am using for long-waiting Ajax calls which would not have any effect on client side:

header("Connection: close");
echo json_encode($out);
header("Content-Length: " . ob_get_length());
// execute your command here. client will not wait for response, it already has one above.

You can find the detailed explanation here:

Delete specified file from document directory

You can double protect your file removal with NSFileManager.defaultManager().isDeletableFileAtPath(PathName) As of now you MUST use do{}catch{} as the old error methods no longer work. isDeletableFileAtPath() is not a "throws" (i.e. "public func removeItemAtPath(path: String) throws") so it does not need the do...catch

let killFile = NSFileManager.defaultManager()

            if (killFile.isDeletableFileAtPath(PathName)){

                do {
                  try killFile.removeItemAtPath(arrayDictionaryFilePath)
                catch let error as NSError {

Double % formatting question for printf in Java

Following is the list of conversion characters that you may use in the printf:

%d – for signed decimal integer

%f – for the floating point

%o – octal number

%c – for a character

%s – a string

%i – use for integer base 10

%u – for unsigned decimal number

%x – hexadecimal number

%% – for writing % (percentage)

%n – for new line = \n

Java: Literal percent sign in printf statement

The percent sign is escaped using a percent sign:


The complete syntax can be accessed in java docs. This particular information is in the section Conversions of the first link.

The reason the compiler is generating an error is that only a limited amount of characters may follow a backslash. % is not a valid character.

Posting form to different MVC post action depending on the clicked submit button


ActionNameSelectorAttribute mentioned in

  1. How do you handle multiple submit buttons in ASP.NET MVC Framework?

  2. ASP.Net MVC 4 Form with 2 submit buttons/actions


Reference: dotnet-tricks - Handling multiple submit buttons on the same form - MVC Razor

Second Approach

Adding a new Form for handling Cancel button click. Now, on Cancel button click we will post the second form and will redirect to the home page.

Third Approach: Client Script

<button name="ClientCancel" type="button" 
    onclick=" document.location.href = $('#cancelUrl').attr('href');">Cancel (Client Side)
<a id="cancelUrl" href="@Html.AttributeEncode(Url.Action("Index", "Home"))" 

Which characters are valid/invalid in a JSON key name?

It is worth mentioning that while starting the keys with numbers is valid, it could cause some unintended issues.


var testObject = {
    "1tile": "test value"
console.log(testObject.1tile); // fails, invalid syntax
console.log(testObject["1tile"]; // workaround

How to solve ERR_CONNECTION_REFUSED when trying to connect to localhost running IISExpress - Error 502 (Cannot debug from Visual Studio)?

I've solved by going to Project Properties -> Debug, after enable SSL and use the address in your browser

enter image description here

Link a photo with the cell in excel

Hold down the Alt key and drag the pictures to snap to the upper left corner of the cell.

Format the picture and in the Properties tab select "Move but don't size with cells"

Now you can sort the data table by any column and the pictures will stay with the respective data.

This post at SuperUser has a bit more background and screenshots:

How to download python from command-line?

apt-get install python2.7 will work on debian-like linuxes. The python website describes a whole bunch of other ways to get Python.

How to use the command update-alternatives --config java

You will notice a big change when selecting options if you type in "java -version" after doing so. So if you run update-alternatives --config java and select option 3, you will be using the Sun implementation.
Also, with regards to auto vs manual mode, making a selection should take it out of auto mode per this page stating:

When using the --config option, alternatives will list all of the choices for the link group of which given name is the master link. You will then be prompted for which of the choices to use for the link group. Once you make a change, the link group will no longer be in auto mode. You will need to use the --auto option in order to return to the automatic state.

And I believe auto mode is set when you install the first/only JRE/JDK.

Convert int (number) to string with leading zeros? (4 digits)

Use the ToString() method - standard and custom numeric format strings. Have a look at the MSDN article How to: Pad a Number with Leading Zeros.

string text = no.ToString("0000");

How can I get the named parameters from a URL using Flask?

The URL parameters are available in request.args, which is an ImmutableMultiDict that has a get method, with optional parameters for default value (default) and type (type) - which is a callable that converts the input value to the desired format. (See the documentation of the method for more details.)

from flask import request

def my_route():
  page = request.args.get('page', default = 1, type = int)
  filter = request.args.get('filter', default = '*', type = str)

Examples with the code above:

/my-route?page=34               -> page: 34  filter: '*'
/my-route                       -> page:  1  filter: '*'
/my-route?page=10&filter=test   -> page: 10  filter: 'test'
/my-route?page=10&filter=10     -> page: 10  filter: '10'
/my-route?page=*&filter=*       -> page:  1  filter: '*' how to deserialize without using the default constructor?

Json.Net prefers to use the default (parameterless) constructor on an object if there is one. If there are multiple constructors and you want Json.Net to use a non-default one, then you can add the [JsonConstructor] attribute to the constructor that you want Json.Net to call.

public Result(int? code, string format, Dictionary<string, string> details = null)

It is important that the constructor parameter names match the corresponding property names of the JSON object (ignoring case) for this to work correctly. You do not necessarily have to have a constructor parameter for every property of the object, however. For those JSON object properties that are not covered by the constructor parameters, Json.Net will try to use the public property accessors (or properties/fields marked with [JsonProperty]) to populate the object after constructing it.

If you do not want to add attributes to your class or don't otherwise control the source code for the class you are trying to deserialize, then another alternative is to create a custom JsonConverter to instantiate and populate your object. For example:

class ResultConverter : JsonConverter
    public override bool CanConvert(Type objectType)
        return (objectType == typeof(Result));

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        // Load the JSON for the Result into a JObject
        JObject jo = JObject.Load(reader);

        // Read the properties which will be used as constructor parameters
        int? code = (int?)jo["Code"];
        string format = (string)jo["Format"];

        // Construct the Result object using the non-default constructor
        Result result = new Result(code, format);

        // (If anything else needs to be populated on the result object, do that here)

        // Return the result
        return result;

    public override bool CanWrite
        get { return false; }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        throw new NotImplementedException();

Then, add the converter to your serializer settings, and use the settings when you deserialize:

JsonSerializerSettings settings = new JsonSerializerSettings();
settings.Converters.Add(new ResultConverter());
Result result = JsonConvert.DeserializeObject<Result>(jsontext, settings);

Converting Long to Date in Java returns 1970

The Date constructor (click the link!) accepts the time as long in milliseconds, not seconds. You need to multiply it by 1000 and make sure that you supply it as long.

Date d = new Date(1220227200L * 1000);

This shows here

Sun Aug 31 20:00:00 GMT-04:00 2008

Android device is not connected to USB for debugging (Android studio)

Well, in my case updating drivers, restarting Android Studio, restarting my phone, changing the USB mode or unplugging USB did not help.

Then I went to the dev settings in my phone, toggled the Dev. Mode off and back on, and it worked. AS was open and phone was plugged at the moment.

Parsing JSON array into java.util.List with Gson

I was able to get the list mapping to work with just using @SerializedName for all fields.. no logic around Type was necessary.

Running the code - in step #4 below - through the debugger, I am able to observe that the List<ContentImage> mGalleryImages object populated with the JSON data

Here's an example:

1. The JSON

    "name": "Some House",
    "gallery": [
        "description": "Nice 300sqft. den.jpg",
        "photo_url": "image/den.jpg"
        "description": "Floor Plan",
        "photo_url": "image/floor_plan.jpg"

2. Java class with the List

public class FocusArea {

    private String mName;

    private List<ContentImage> mGalleryImages;

3. Java class for the List items

public class ContentImage {

    private String mDescription;

    private String mPhotoUrl;

    // getters/setters ..

4. The Java code that processes the JSON

    for (String key : focusAreaKeys) {

        JsonElement sectionElement = sectionsJsonObject.get(key);
        FocusArea focusArea = gson.fromJson(sectionElement, FocusArea.class);

How do I search for an object by its ObjectId in the mongo console?

In MongoDB Stitch functions it can be done using BSON like below:

Use the ObjectId helper in the BSON utility package for this purpose like in the follwing example:

var id = "5bb9e9f84186b222c8901149";  

How to make a TextBox accept only alphabetic characters?

This works fine as far as characters restriction, Any suggestions on error msg prompt with my code if it's not C OR L

Private Sub TXTBOX_TextChanged(sender As System.Object, e As System.EventArgs) Handles TXTBOX.TextChanged

        Dim allowed As String = "C,L"
        For Each C As Char In TXTBOX.Text
            If allowed.Contains(C) = False Then

                TXTBOX.Text = TXTBOX.Text.Remove(TXTBOX.SelectionStart - 1, 1)
                TXTBOX.Select(TXTBOX.Text.Count, 0)

            End If

    End Sub

What I can do to resolve "1 commit behind master"?

  1. Clone your fork:

  2. Add remote from original repository in your forked repository:

    • cd into/cloned/fork-repo
    • git remote add upstream git://
    • git fetch upstream
  3. Updating your fork from original repo to keep up with their changes:

    • git pull upstream master
    • git push

Access non-numeric Object properties by index?

The only way I can think of doing this is by creating a method that gives you the property using Object.keys();.

var obj = {
    dog: "woof",
    cat: "meow",
    key: function(n) {
        return this[Object.keys(this)[n]];
obj.key(1); // "meow"


It would be possible to extend this to all objects using Object.prototype; but that isn't usually recommended.

Instead, use a function helper:

var object = {
  key: function(n) {
    return this[ Object.keys(this)[n] ];

function key(obj, idx) {
  return, idx);

key({ a: 6 }, 0); // 6

bootstrap 3 wrap text content within div for horizontal alignment

Now Update word-wrap is replace by :


Compatible old navigator and css 3 it's good alternative !

it's evolution of word-wrap ( since 2012... )

See more information :

See compatibility full :

Center the nav in Twitter Bootstrap

Code used basic nav bootstrap

<!--MENU CENTER`enter code here` RESPONSIVE -->_x000D_
  <div class="container-fluid">_x000D_
        <div class="container logo"><h1>LOGO</h1></div>_x000D_
      <nav class="navbar navbar-default menu">_x000D_
        <div class="container-fluid">_x000D_
          <!-- Brand and toggle get grouped for better mobile display -->_x000D_
          <div class="navbar-header">_x000D_
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#defaultNavbar2"><span class="sr-only">Toggle navigation</span><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span></button>_x000D_
          <!-- Collect the nav links, forms, and other content for toggling -->_x000D_
          <div class="collapse navbar-collapse" id="defaultNavbar2">_x000D_
            <ul class="nav nav-justified" >_x000D_
              <li><a href="#">Home</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
              <li><a href="#">Link</a></li>_x000D_
          <!-- /.navbar-collapse -->_x000D_
        <!-- /.container-fluid -->_x000D_
  <!-- END MENU-->

Solving "adb server version doesn't match this client" error

In my case the solution was this on an Ubuntu based OS:

adb kill-server
sudo cp ~/Android/Sdk/platform-tools/adb /usr/bin/adb
sudo chmod +x /usr/bin/adb
adb start-server


The type initializer for 'MyClass' threw an exception

One other thing to check when these initialize errors are thrown would be to check if the target .NET version is installed on the server. You can right click the project and see what .NET version the application is targeting.

Android: Getting "Manifest merger failed" error after updating to a new version of gradle

The error for me was:

Manifest merger failed : Attribute value=(26.0.2) from [] AndroidManifest.xml:25:13-35
    is also present at [] AndroidManifest.xml:28:13-35 value=(26.1.0).
    Suggestion: add 'tools:replace="android:value"' to <meta-data> element at AndroidManifest.xml:23:9-25:38 to override.

The solution for me was in my project Gradle file I needed to bump my version.

I was using version 3.1.1:

classpath '

And the error resolved after I bumped it to version 3.2.1:

classpath '

I had just upgraded all my libraries to the latest including v27.1.1 of all the support libraries and v15.0.0 of all the Firebase libraries when I saw the error.

Convert date time string to epoch in Bash

Efficient solution using date as background dedicated process

In order to make this kind of translation a lot quicker...


In this post, you will find

  • a Quick Demo, following this,
  • some Explanations,
  • a Function useable for many Un*x tools (bc, rot13, sed...).

Quick Demo

mkfifo $fifo
exec 5> >(exec stdbuf -o0 date -f - +%s >$fifo 2>&1)
echo now 1>&5
exec 6< $fifo
rm $fifo
read -t 1 -u 6 now
echo $now

This must output current UNIXTIME. From there, you could compare

time for i in {1..5000};do echo >&5 "now" ; read -t 1 -u6 ans;done
real    0m0.298s
user    0m0.132s
sys     0m0.096s


time for i in {1..5000};do ans=$(date +%s -d "now");done 
real    0m6.826s
user    0m0.256s
sys     0m1.364s

From more than 6 seconds to less than a half second!!(on my host).

You could check echo $ans, replace "now" by "2019-25-12 20:10:00" and so on...

Optionaly, you could, once requirement of date subprocess ended:

exec 5>&- ; exec 6<&-

Original post (detailed explanation)

Instead of running 1 fork by date to convert, run date just 1 time and do all convertion with same process (this could become a lot quicker)!:

date -f - +%s <<eof
Apr 17  2014
May 21  2012
Mar  8 00:07
Feb 11 00:09


start1=$(LANG=C ps ho lstart 1)
start2=$(LANG=C ps ho lstart $$)
dirchg=$(LANG=C date -r .)
read -p "A date: " userdate
{ read start1 ; read start2 ; read dirchg ; read userdate ;} < <(
   date -f - +%s <<<"$start1"$'\n'"$start2"$'\n'"$dirchg"$'\n'"$userdate" )

Then now have a look:

declare -p start1 start2 dirchg userdate

(may answer something like:

declare -- start1="1518549549"
declare -- start2="1520183716"
declare -- dirchg="1520601919"
declare -- userdate="1397685600"

This was done in one execution!

Using long running subprocess

We just need one fifo:

mkfifo /tmp/myDateFifo
exec 7> >(exec stdbuf -o0 /bin/date -f - +%s >/tmp/myDateFifo)
exec 8</tmp/myDateFifo
rm /tmp/myDateFifo

(Note: As process is running and all descriptors are opened, we could safely remove fifo's filesystem entry.)

Then now:

LANG=C ps ho lstart 1 $$ >&7
read -u 8 start1
read -u 8 start2
LANG=C date -r . >&7
read -u 8 dirchg

read -p "Some date: " userdate
echo >&7 $userdate
read -u 8 userdate

We could buid a little function:

mydate() {
    local var=$1;
    echo >&7 $@
    read -u 8 $var

mydate start1 $(LANG=C ps ho lstart 1)
echo $start1

Or use my newConnector function

With functions for connecting MySQL/MariaDB, PostgreSQL and SQLite...

You may find them in different version on GitHub, or on my site: download or show.


. shell_connector.bash 
newConnector /bin/date '-f - +%s' @0 0

myDate "2018-1-1 12:00" test
echo $test

Nota: On GitHub, functions and test are separated files. On my site test are run simply if this script is not sourced.

# Exit here if script is sourced
[ "$0" = "$BASH_SOURCE" ] || { true;return 0;}

How can I group data with an Angular filter?

You can use groupBy of angular.filter module.
so you can do something like this:


$scope.players = [
  {name: 'Gene', team: 'alpha'},
  {name: 'George', team: 'beta'},
  {name: 'Steve', team: 'gamma'},
  {name: 'Paula', team: 'beta'},
  {name: 'Scruath', team: 'gamma'}


<ul ng-repeat="(key, value) in players | groupBy: 'team'">
  Group name: {{ key }}
  <li ng-repeat="player in value">
    player: {{ }} 

Group name: alpha
* player: Gene
Group name: beta
* player: George
* player: Paula
Group name: gamma
* player: Steve
* player: Scruath

UPDATE: jsbin Remember the basic requirements to use angular.filter, specifically note you must add it to your module's dependencies:

(1) You can install angular-filter using 4 different methods:

  1. clone & build this repository
  2. via Bower: by running $ bower install angular-filter from your terminal
  3. via npm: by running $ npm install angular-filter from your terminal
  4. via cdnjs

(2) Include angular-filter.js (or angular-filter.min.js) in your index.html, after including Angular itself.

(3) Add 'angular.filter' to your main module's list of dependencies.

XPath: difference between dot and text()

There is big difference between dot (".") and text() :-

  • The dot (".") in XPath is called the "context item expression" because it refers to the context item. This could be match with a node (such as an element, attribute, or text node) or an atomic value (such as a string, number, or boolean). While text() refers to match only element text which is in string form.

  • The dot (".") notation is the current node in the DOM. This is going to be an object of type Node while Using the XPath function text() to get the text for an element only gets the text up to the first inner element. If the text you are looking for is after the inner element you must use the current node to search for the string and not the XPath text() function.

For an example :-

<a href="something.html">
  <img src="filename.gif">

Here if you want to find anchor a element by using text link, you need to use dot ("."). Because if you use //a[contains(.,'link')] it finds the anchor a element but if you use //a[contains(text(),'link')] the text() function does not seem to find it.

Hope it will help you..:)

How to extract a floating number from a string

You can use the following regex to get integer and floating values from a string:

re.findall(r'[\d\.\d]+', 'hello -34 42 +34.478m 88 cricket -44.3')

['34', '42', '34.478', '88', '44.3']

Thanks Rex

Where Sticky Notes are saved in Windows 10 1607

In windows 10 you can recover in this way, there is no .snt file

  1. Start Run
  2. Go to this %LocalAppData%\Packages\Microsoft.MicrosoftStickyNotes_8wekyb3d8bbwe
  3. Copy this folder Microsoft.MicrosoftStickyNotes_8wekyb3d8bbwe
  4. Replace it with new Microsoft.MicrosoftStickyNotes_8wekyb3d8bbwe
  5. Check your sticky notes now, you will get all your data

How to convert integer into date object python?

Here is what I believe answers the question (Python 3, with type hints):

from datetime import date

def int2date(argdate: int) -> date:
    If you have date as an integer, use this method to obtain a object.

    argdate : int
      Date as a regular integer value (example: 20160618)

      A date object which corresponds to the given value `argdate`.
    year = int(argdate / 10000)
    month = int((argdate % 10000) / 100)
    day = int(argdate % 100)

    return date(year, month, day)


The code above produces the expected 2016-06-18.

Convert Python dict into a dataframe

This is what worked for me, since I wanted to have a separate index column

df = pd.DataFrame.from_dict(some_dict, orient="index").reset_index()
df.columns = ['A', 'B']

Bash integer comparison

Easier solution;

if (( ${1:-2} >= 2 )); then
    echo "First parameter must be 0 or 1"
# rest of script...


$ ./test 
First parameter must be 0 or 1
$ ./test 0
$ ./test 1
$ ./test 4
First parameter must be 0 or 1
$ ./test 2
First parameter must be 0 or 1


  • (( )) - Evaluates the expression using integers.
  • ${1:-2} - Uses parameter expansion to set a value of 2 if undefined.
  • >= 2 - True if the integer is greater than or equal to two 2.

Do while loop in SQL Server 2008

Only While Loop is officially supported by SQL server. Already there is answer for DO while loop. I am detailing answer on ways to achieve different types of loops in SQL server.

If you know, you need to complete first iteration of loop anyway, then you can try DO..WHILE or REPEAT..UNTIL version of SQL server.



WAY:  --> Here the  DO statement


  SET @X += 1;




WAY:  -- Here the REPEAT statement


  SET @X += 1;


FOR Loop

DECLARE @cnt INT = 0;

WHILE @cnt < 10
   PRINT 'Inside FOR LOOP';
   SET @cnt = @cnt + 1;



How to create a sticky navigation bar that becomes fixed to the top after scrolling

//in html

<nav class="navbar navbar-default" id="mainnav">

// add in jquery

$(document).ready(function() {
  var navpos = $('#mainnav').offset();
    $(window).bind('scroll', function() {
      if ($(window).scrollTop() > {
       else {

Here is the jsfiddle to play around : -

EDIT: if you want to apply this code only for mobile devices the you can use:

   var newWindowWidth = $(window).width();
    if (newWindowWidth < 481) {
        //Place code inside it...

Query to get the names of all tables in SQL Server 2008 Database

Please use the following query to list the tables in your DB.

select name from sys.Tables 

In Addition, you can add a where condition, to skip system generated tables and lists only user created table by adding type ='U'

Ex : select name from sys.Tables where type ='U'

Javascript sleep/delay/wait function

Here's a solution using the new async/await syntax.

async function testWait() {
    alert('going to wait for 5 second');
    await wait(5000);
    alert('finally wait is over');

function wait(time) {
    return new Promise(resolve => {
        setTimeout(() => {
        }, time);

Note: You can call function wait only in async functions

Hive load CSV with commas in quoted fields

keep the delimiter in single quotes it will work.


This will work

How can I do an asc and desc sort using underscore.js?

You can use .sortBy, it will always return an ascending list:

_.sortBy([2, 3, 1], function(num) {
    return num;
}); // [1, 2, 3]

But you can use the .reverse method to get it descending:

var array = _.sortBy([2, 3, 1], function(num) {
    return num;

console.log(array); // [1, 2, 3]
console.log(array.reverse()); // [3, 2, 1]

Or when dealing with numbers add a negative sign to the return to descend the list:

_.sortBy([-3, -2, 2, 3, 1, 0, -1], function(num) {
    return -num;
}); // [3, 2, 1, 0, -1, -2, -3]

Under the hood .sortBy uses the built in .sort([handler]):

// Default is ascending:
[2, 3, 1].sort(); // [1, 2, 3]

// But can be descending if you provide a sort handler:
[2, 3, 1].sort(function(a, b) {
    // a = current item in array
    // b = next item in array
    return b - a;

Show/hide forms using buttons and JavaScript

There's something I bet you already heard about this! It's called jQuery.

$("#button1").click(function() {

It's really easy and you can use CSS-like selectors and you can add animations. It's really easy to learn.

How to see PL/SQL Stored Function body in Oracle

SELECT text 
FROM all_source
order by line


select dbms_metadata.get_ddl('FUNCTION', 'FGETALGOGROUPKEY')
from dual;

Writing to a TextBox from another thread?

On your MainForm make a function to set the textbox the checks the InvokeRequired

public void AppendTextBox(string value)
    if (InvokeRequired)
        this.Invoke(new Action<string>(AppendTextBox), new object[] {value});
    ActiveForm.Text += value;

although in your static method you can't just call.

WindowsFormsApplication1.Form1.AppendTextBox("hi. ");

you have to have a static reference to the Form1 somewhere, but this isn't really recommended or necessary, can you just make your SampleFunction not static if so then you can just call

AppendTextBox("hi. ");

It will append on a differnt thread and get marshalled to the UI using the Invoke call if required.

Full Sample

public partial class Form1 : Form
    public Form1()
        new Thread(SampleFunction).Start();

    public void AppendTextBox(string value)
        if (InvokeRequired)
            this.Invoke(new Action<string>(AppendTextBox), new object[] {value});
        textBox1.Text += value;

    void SampleFunction()
        // Gets executed on a seperate thread and 
        // doesn't block the UI while sleeping
        for(int i = 0; i<5; i++)
            AppendTextBox("hi.  ");

How can I simulate an array variable in MySQL?

Nowadays using a JSON array would be an obvious answer.

Since this is an old but still relevant question I produced a short example. JSON functions are available since mySQL 5.7.x / MariaDB 10.2.3

I prefer this solution over ELT() because it's really more like an array and this 'array' can be reused in the code.

But be careful: It (JSON) is certainly much slower than using a temporary table. Its just more handy. imo.

Here is how to use a JSON array:

SET @myjson = '["","","","","",

-- result: 19

SELECT JSON_VALUE(@myjson, '$[0]');
-- result:

And here a little example to show how it works in a function/procedure:

  DECLARE _result varchar(1000) DEFAULT '';
  DECLARE _value varchar(50);

  SET @myjson = '["","","","","",

  WHILE _counter < JSON_LENGTH(@myjson) DO
    -- do whatever, e.g. add-up strings...
    SET _result = CONCAT(_result, _counter, '-', JSON_VALUE(@myjson, CONCAT('$[',_counter,']')), '#');

    SET _counter = _counter + 1;

  RETURN _result;
END //

SELECT example();

How do I disable Git Credential Manager for Windows?

Another option I had to use with VSTS:

git config credential.modalprompt false --global

How Exactly Does @param Work - Java

It is basically a comment. As we know, a number of people working on the same project must have knowledge about the code changes. We are making some notes in the program about the parameters.

How to specify the download location with wget?

From the manual page:

-P prefix
           Set directory prefix to prefix.  The directory prefix is the
           directory where all other files and sub-directories will be
           saved to, i.e. the top of the retrieval tree.  The default
           is . (the current directory).

So you need to add -P /tmp/cron_test/ (short form) or --directory-prefix=/tmp/cron_test/ (long form) to your command. Also note that if the directory does not exist it will get created.

MySQL: Grant **all** privileges on database

To access from remote server to mydb database only

GRANT ALL PRIVILEGES ON mydb.* TO 'root'@'';

To access from remote server to all databases.


Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly

I had the same error and could not figure it out with the other answers. I found that we can "Consolidate" NuGet packages.

  1. Right click on the solution
  2. Click Manage Nuget Packages
  3. Consolidate tab and update to the same version.