Programs & Examples On #Treetable

Query plugin for displaying a tree structure in a (HTML) table, i.e. a directory structure or a nested list.

Java GUI frameworks. What to choose? Swing, SWT, AWT, SwingX, JGoodies, JavaFX, Apache Pivot?

SWT by itself is pretty low-level, and it uses the platform's native widgets through JNI. It is not related to Swing and AWT at all. The Eclipse IDE and all Eclipse-based Rich Client Applications, like the Vuze BitTorrent client, are built using SWT. Also, if you are developing Eclipse plugins, you will typically use SWT.
I have been developing Eclipse-based applications and plugins for almost 5 years now, so I'm clearly biased. However, I also have extensive experience in working with SWT and the JFace UI toolkit, which is built on top of it. I have found JFace to be very rich and powerful; in some cases it might even be the main reason for choosing SWT. It enables you to whip up a working UI quite quickly, as long as it is IDE-like (with tables, trees, native controls, etc). Of course you can integrate your custom controls as well, but that takes some extra effort.

GUI-based or Web-based JSON editor that works like property explorer

Generally when I want to create a JSON or YAML string, I start out by building the Perl data structure, and then running a simple conversion on it. You could put a UI in front of the Perl data structure generation, e.g. a web form.

Converting a structure to JSON is very straightforward:

use strict;
use warnings;
use JSON::Any;

my $data = { arbitrary structure in here };
my $json_handler = JSON::Any->new(utf8=>1);
my $json_string = $json_handler->objToJson($data);

Prevent wrapping of span or div

It works with just this:

.slideContainer {
    white-space: nowrap;
.slide { 
    display: inline-block;
    width: 600px;
    white-space: normal;

I did originally have float : left; and that prevented it from working correctly.

Thanks for posting this solution.

How to perform an SQLite query within an Android application?

This will return you the required cursor

Cursor cursor = db.query(TABLE_NAME, new String[] {"_id", "title", "title_raw"}, 
                "title_raw like " + "'%Smith%'", null, null, null, null);

What is the best practice for creating a favicon on a web site?

I used I uploaded my image, downloaded images zip file, added images to my server, followed the directions on the site including adding the links to my index.html and it worked. My favicon now shows on my iPhone in Safari when 'Add to home screen'

jQuery: count number of rows in a table

var trLength = jQuery('#tablebodyID >tr').length;

Material effect on button with background color

There are two approaches explained in the great tutorial be Alex Lockwood:

Approach #1: Modifying the button’s background color w/ a ThemeOverlay

<!-- res/values/themes.xml -->
<style name="RedButtonLightTheme" parent="ThemeOverlay.AppCompat.Light">
    <item name="colorAccent">@color/googred500</item>


Approach #2: Setting the AppCompatButton’s background tint

<!-- res/color/btn_colored_background_tint.xml -->
<selector xmlns:android="">

    <!-- Disabled state. -->
    <item android:state_enabled="false"

    <!-- Enabled state. -->
    <item android:color="?attr/colorAccent"/>



Checking if a list of objects contains a property with a specific value

myList.Where(item=>item.Name == nameToExtract)

Parsing JSON from XmlHttpRequest.responseJSON

New ways I: fetch

TL;DR I'd recommend this way as long as you don't have to send synchronous requests or support old browsers.

A long as your request is asynchronous you can use the Fetch API to send HTTP requests. The fetch API works with promises, which is a nice way to handle asynchronous workflows in JavaScript. With this approach you use fetch() to send a request and ResponseBody.json() to parse the response:

  .then(function(response) {
    return response.json();
  .then(function(jsonResponse) {
    // do something with jsonResponse

Compatibility: The Fetch API is not supported by IE11 as well as Edge 12 & 13. However, there are polyfills.

New ways II: responseType

As Londeren has written in his answer, newer browsers allow you to use the responseType property to define the expected format of the response. The parsed response data can then be accessed via the response property:

var req = new XMLHttpRequest();
req.responseType = 'json';'GET', url, true);
req.onload  = function() {
   var jsonResponse = req.response;
   // do something with jsonResponse

Compatibility: responseType = 'json' is not supported by IE11.

The classic way

The standard XMLHttpRequest has no responseJSON property, just responseText and responseXML. As long as bitly really responds with some JSON to your request, responseText should contain the JSON code as text, so all you've got to do is to parse it with JSON.parse():

var req = new XMLHttpRequest();
req.overrideMimeType("application/json");'GET', url, true);
req.onload  = function() {
   var jsonResponse = JSON.parse(req.responseText);
   // do something with jsonResponse

Compatibility: This approach should work with any browser that supports XMLHttpRequest and JSON.


If you prefer to use responseJSON, but want a more lightweight solution than JQuery, you might want to check out my JSONHttpRequest. It works exactly like a normal XMLHttpRequest, but also provides the responseJSON property. All you have to change in your code would be the first line:

var req = new JSONHttpRequest();

JSONHttpRequest also provides functionality to easily send JavaScript objects as JSON. More details and the code can be found here:

Full disclosure: I'm the owner of Pixels|Bytes. I thought that my script was a good solution for the original question, but it is rather outdated today. I do not recommend to use it anymore.

Failed to decode downloaded font, OTS parsing error: invalid version tag + rails 4


@font-face {
  font-family: 'icomoon';
  src: asset-url('icomoon.eot');
  src: asset-url('icomoon.eot?#iefix') format('embedded-opentype'),
       asset-url('icomoon.ttf') format('truetype'),
       asset-url('icomoon.woff') format('woff'),
       asset-url('icomoon.svg#icomoon') format('svg');
  font-weight: normal;
  font-style: normal;

and rename your file to application.css.scss

coercing to Unicode: need string or buffer, NoneType found when rendering in django admin

Replace the earlier function with the provided one. The simplest solution is:

def __unicode__(self):

    return unicode(self.nom_du_site)

How do I make a Git commit in the past?

You can create the commit as usual, but when you commit, set the environment variables GIT_AUTHOR_DATE and GIT_COMMITTER_DATE to the appropriate datetimes.

Of course, this will make the commit at the tip of your branch (i.e., in front of the current HEAD commit). If you want to push it back farther in the repo, you have to get a bit fancy. Let's say you have this history:


And you want your new commit (marked as "X") to appear second:


The easiest way would be to branch from the first commit, add your new commit, then rebase all other commits on top of the new one. Like so:

$ git checkout -b new_commit $desired_parent_of_new_commit
$ git add new_file
$ GIT_AUTHOR_DATE='your date' GIT_COMMITTER_DATE='your date' git commit -m 'new (old) files'
$ git checkout master
$ git rebase new_commit
$ git branch -d new_commit

Attach parameter to button.addTarget action in Swift

If you have a loop of buttons like me you can try something like this

var buttonTags:[Int:String]? // can be [Int:Any]
let myArray = [0:"a",1:"b"]
for (index,value) in myArray {

     let button = // Create a button

     buttonTags?[index] = myArray[index]
     button.tag = index
     button.addTarget(self, action: #selector(buttonAction(_:)), for: .touchDown)

@objc func buttonAction(_ sender:UIButton) {

    let myString = buttonTags[sender.tag]


Regular Expression for password validation

I would check them one-by-one; i.e. look for a number \d+, then if that fails you can tell the user they need to add a digit. This avoids returning an "Invalid" error without hinting to the user whats wrong with it.

iPhone App Minus App Store?

It's worth noting that if you go the jailbroken route, it's possible (likely?) that an iPhone OS update would kill your ability to run these apps. I'd go the official route and pay the $99 to get authorized. In addition to not having to worry about your apps being clobbered, you also get the opportunity (should you choose) to release your apps on the store.

How do you add an SDK to Android Studio?

And For linux(ubuntu)


Putting text in top left corner of matplotlib plot

One solution would be to use the plt.legend function, even if you don't want an actual legend. You can specify the placement of the legend box by using the loc keyterm. More information can be found at this website but I've also included an example showing how to place a legend:

ax.scatter(xa,ya, marker='o', s=20, c="lightgreen", alpha=0.9)
ax.scatter(xb,yb, marker='o', s=20, c="dodgerblue", alpha=0.9)
ax.scatter(xc,yc marker='o', s=20, c="firebrick", alpha=1.0)
ax.scatter(xd,xd,xd, marker='o', s=20, c="goldenrod", alpha=0.9)
line1 = Line2D(range(10), range(10), marker='o', color="goldenrod")
line2 = Line2D(range(10), range(10), marker='o',color="firebrick")
line3 = Line2D(range(10), range(10), marker='o',color="lightgreen")
line4 = Line2D(range(10), range(10), marker='o',color="dodgerblue")
plt.legend((line1,line2,line3, line4),('line1','line2', 'line3', 'line4'),numpoints=1, loc=2) 

Note that because loc=2, the legend is in the upper-left corner of the plot. And if the text overlaps with the plot, you can make it smaller by using legend.fontsize, which will then make the legend smaller.

Auto refresh page every 30 seconds

Just a simple line of code in the head section can refresh the page

<meta http-equiv="refresh" content="30">

although its not a javascript function, its the simplest way to accomplish the above task hopefully.

Loading local JSON file

In TypeScript you can use import to load local JSON files. For example loading a font.json:

import * as fontJson from '../../public/fonts/font_name.json';

This requires a tsconfig flag --resolveJsonModule:

// tsconfig.json

    "compilerOptions": {
        "module": "commonjs",
        "resolveJsonModule": true,
        "esModuleInterop": true

For more information see the release notes of typescript:

Heroku 'Permission denied (publickey) fatal: Could not read from remote repository' woes

I know this has already been answered. But I would like to add my solution as it may helpful for others in the future..

A common key error is: Permission denied (publickey). You can fix this by using keys:add to notify Heroku of your new key.

In short follow these steps:

First you have to create a key if you don't have one:

ssh-keygen -t rsa

Second you have to add the key to Heroku:

heroku keys:add

How do I make a relative reference to another workbook in Excel?

easier & shorter via indirect: INDIRECT("'..\..\..\..\Supply\SU\SU.ods'#$Data.$A$2:$AC$200")

however indirect() has performance drawbacks if lot of links in workbook

I miss construct like: ['../Data.ods']#Sheet1.A1 in LibreOffice. The intention is here: if I create a bunch of master workbooks and depending report workbooks in limited subtree of directories in source file system, I can zip whole directory subtree with complete package of workbooks and send it to other cooperating person per Email or so. It will be saved in some other absolute pazth on target system, but linkage works again in new absolute path because it was coded relatively to subtree root.

changing kafka retention period during runtime

The following is the right way to alter topic config as of Kafka

bin/ --zookeeper <zk_host> --alter --entity-type topics --entity-name test_topic --add-config

Topic config alter operations have been deprecated for bin/

WARNING: Altering topic configuration from this script has been deprecated and may be removed in future releases.
     Going forward, please use for this functionality`

How to import Angular Material in project?

The MaterialModule was deprecated in the beta3 version with the goal that developers should only import into their applications what they are going to use and thus improve the bundle size.

The developers have now 2 options:

  • Create a custom MyMaterialModule which imports/exports the components that your application requires and can be imported by other (feature) modules in your application.
  • Import directly the individual material modules that a module requires into it.

Take the following as example (extracted from material page)

First approach:

import {MdButtonModule, MdCheckboxModule} from '@angular/material';

  imports: [MdButtonModule, MdCheckboxModule],
  exports: [MdButtonModule, MdCheckboxModule],
export class MyOwnCustomMaterialModule { }

Then you can import this module into any of yours.

Second approach:

import {MdButtonModule, MdCheckboxModule} from '@angular/material';

  imports: [MdButtonModule, MdCheckboxModule],
export class PizzaPartyAppModule { }

Now you can use the respective material components in all the components declared in PizzaPartyAppModule

It is worth mentioning the following:

  • With the latest version of material, you need to import BrowserAnimationsModule into your main module if you want the animations to work
  • With the latest version developers now need to add @angular/cdk to their package.json (material dependency)
  • Import the material modules always after BrowserModule, as stated by the docs:

Whichever approach you use, be sure to import the Angular Material modules after Angular's BrowserModule, as the import order matters for NgModules.

Checkbox Check Event Listener

Since I don't see the jQuery tag in the OP, here is a javascript only option :

document.addEventListener("DOMContentLoaded", function (event) {
    var _selector = document.querySelector('input[name=myCheckbox]');
    _selector.addEventListener('change', function (event) {
        if (_selector.checked) {
            // do something if checked
        } else {
            // do something else otherwise


Install msi with msiexec in a Specific Directory

Use TARGETDIR instead of INSTALLDIR. Note that the quote marks for TARGETDIR property are only around the path in the case of spaces.

msiexec /i "msi path" TARGETDIR="C:\myfolder" /qb

How to make a phone call using intent in Android?

Permission in AndroidManifest.xml

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

Complete code:

private void onCallBtnClick(){
    if (Build.VERSION.SDK_INT < 23) {
    }else {

        if (ActivityCompat.checkSelfPermission(mActivity,
                Manifest.permission.CALL_PHONE) == PackageManager.PERMISSION_GRANTED) {

        }else {
            final String[] PERMISSIONS_STORAGE = {Manifest.permission.CALL_PHONE};
            //Asking request Permissions
            ActivityCompat.requestPermissions(mActivity, PERMISSIONS_STORAGE, 9);

public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    boolean permissionGranted = false;
        case 9:
            permissionGranted = grantResults[0]== PackageManager.PERMISSION_GRANTED;
    }else {
        Toast.makeText(mActivity, "You don't assign permission.", Toast.LENGTH_SHORT).show();

private void phoneCall(){
    if (ActivityCompat.checkSelfPermission(mActivity,
            Manifest.permission.CALL_PHONE) == PackageManager.PERMISSION_GRANTED) {
        Intent callIntent = new Intent(Intent.ACTION_CALL);
        Toast.makeText(mActivity, "You don't assign permission.", Toast.LENGTH_SHORT).show();

Connect Java to a MySQL database

Initialize database constants

Create constant properties database username, password, URL and drivers, polling limit etc.

// init database constants
// com.mysql.jdbc.Driver
private static final String DATABASE_DRIVER = "com.mysql.cj.jdbc.Driver";
private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/database_name";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
private static final String MAX_POOL = "250"; // set your own limit

Initialize Connection and Properties

Once the connection is established, it is better to store for reuse purpose.

// init connection object
private Connection connection;
// init properties object
private Properties properties;

Create Properties

The properties object hold the connection information, check if it is already set.

// create properties
private Properties getProperties() {
    if (properties == null) {
        properties = new Properties();
        properties.setProperty("user", USERNAME);
        properties.setProperty("password", PASSWORD);
        properties.setProperty("MaxPooledStatements", MAX_POOL);
    return properties;

Connect the Database

Now connect to database using the constants and properties initialized.

// connect database
public Connection connect() {
    if (connection == null) {
        try {
            connection = DriverManager.getConnection(DATABASE_URL, getProperties());
        } catch (ClassNotFoundException | SQLException e) {
            // Java 7+
    return connection;

Disconnect the database

Once you are done with database operations, just close the connection.

// disconnect database
public void disconnect() {
    if (connection != null) {
        try {
            connection = null;
        } catch (SQLException e) {

Everything together

Use this class MysqlConnect directly after changing database_name, username and password etc.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class MysqlConnect {
    // init database constants
    private static final String DATABASE_DRIVER = "com.mysql.cj.jdbc.Driver";
    private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/database_name";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "";
    private static final String MAX_POOL = "250";

    // init connection object
    private Connection connection;
    // init properties object
    private Properties properties;

    // create properties
    private Properties getProperties() {
        if (properties == null) {
            properties = new Properties();
            properties.setProperty("user", USERNAME);
            properties.setProperty("password", PASSWORD);
            properties.setProperty("MaxPooledStatements", MAX_POOL);
        return properties;

    // connect database
    public Connection connect() {
        if (connection == null) {
            try {
                connection = DriverManager.getConnection(DATABASE_URL, getProperties());
            } catch (ClassNotFoundException | SQLException e) {
        return connection;

    // disconnect database
    public void disconnect() {
        if (connection != null) {
            try {
                connection = null;
            } catch (SQLException e) {

How to Use?

Initialize the database class.

// !_ note _! this is just init
// it will not create a connection
MysqlConnect mysqlConnect = new MysqlConnect();

Somewhere else in your code ...

String sql = "SELECT * FROM `stackoverflow`";
try {
    PreparedStatement statement = mysqlConnect.connect().prepareStatement(sql);
    ... go on ...
    ... go on ...
    ... DONE ....
} catch (SQLException e) {
} finally {

This is all :) If anything to improve edit it! Hope this is helpful.

How do I query between two dates using MySQL?

DATE() is a MySQL function that extracts only the date part of a date or date/time expression

SELECT * FROM table_name WHERE DATE(date_field) BETWEEN '2016-12-01' AND '2016-12-10';

Saving image to file

You can try with this code

Image.Save("myfile.png", ImageFormat.Png)

Link :

Use sudo with password as parameter

echo -e "YOURPASSWORD\n" | sudo -S yourcommand

IndentationError: unexpected unindent WHY?

It's because you have:

def readTTable(fname):

without a matching except block after the try: block. Every try must have at least one matching except.

See the Errors and Exceptions section of the Python tutorial.

SFTP Libraries for .NET

I've searched around and found that this fork of SharpSSH and SSH.NET are the most up to date and best maintained libraries for SFTP (not to be confused with FTPS) communication in .NET. SSH.NET is a clean .NET 4.0 implementation of the SFTP protocol, and I've used it in a couple of solutions with flying colors and great success.

The original SharpSsh seems to be dead and most other solutions either require installation of Windows executables or a bucketload of cash (or worse; both).

MSIE and addEventListener Problem in Javascript?

try adding

<meta http-equiv="X-UA-Compatible" content="IE=edge"> 

right after the opening head tag

Disable Auto Zoom in Input "Text" tag - Safari on iPhone

Instead of simply setting the font size to 16px, you can:

  1. Style the input field so that it is larger than its intended size, allowing the logical font size to be set to 16px.
  2. Use the scale() CSS transform and negative margins to shrink the input field down to the correct size.

For example, suppose your input field is originally styled with:

input[type="text"] {
    border-radius: 5px;
    font-size: 12px;
    line-height: 20px;
    padding: 5px;
    width: 100%;

If you enlarge the field by increasing all dimensions by 16 / 12 = 133.33%, then reduce using scale() by 12 / 16 = 75%, the input field will have the correct visual size (and font size), and there will be no zoom on focus.

As scale() only affects the visual size, you will also need to add negative margins to reduce the field's logical size.

With this CSS:

input[type="text"] {
    /* enlarge by 16/12 = 133.33% */
    border-radius: 6.666666667px;
    font-size: 16px;
    line-height: 26.666666667px;
    padding: 6.666666667px;
    width: 133.333333333%;

    /* scale down by 12/16 = 75% */
    transform: scale(0.75);
    transform-origin: left top;

    /* remove extra white space */
    margin-bottom: -10px;
    margin-right: -33.333333333%;

the input field will have a logical font size of 16px while appearing to have 12px text.

I have a blog post where I go into slightly more detail, and have this example as viewable HTML:
No input zoom in Safari on iPhone, the pixel perfect way

Save array in mysql database

Use the PHP function serialize() to convert arrays to strings. These strings can easily be stored in MySQL database. Using unserialize() they can be converted to arrays again if needed.

git diff between cloned and original remote repository

Another reply to your questions (assuming you are on master and already did "git fetch origin" to make you repo aware about remote changes):

1) Commits on remote branch since when local branch was created:

git diff HEAD...origin/master

2) I assume by "working copy" you mean your local branch with some local commits that are not yet on remote. To see the differences of what you have on your local branch but that does not exist on remote branch run:

git diff origin/master...HEAD

3) See the answer by dbyrne.

How to access environment variable values?

For django see (

$ pip install django-environ

import environ
env = environ.Env(
# set casting, default value
DEBUG=(bool, False)
# reading .env file

# False if not in os.environ
DEBUG = env('DEBUG')

# Raises django's ImproperlyConfigured exception if SECRET_KEY not in os.environ

How to access the services from RESTful API in my angularjs page?

For instance your json looks like this : {"id":1,"content":"Hello, World!"}

You can access this thru angularjs like so:

angular.module('app', [])
    .controller('myApp', function($scope, $http) {
            then(function(response) {
                $scope.datafromapi =;

Then on your html you would do it like this:

<!doctype html>
<html ng-app="myApp">
        <title>Hello AngularJS</title>
        <script src=""></script>
        <script src="hello.js"></script>

        <div ng-controller="myApp">
            <p>The ID is {{}}</p>
            <p>The content is {{datafromapi.content}}</p>

This calls the CDN for angularjs in case you don't want to download them.

<script src=""></script>
<script src="hello.js"></script>

Hope this helps.

Android EditText view Floating Hint in Material Design

Yes, as of May 29, 2015 this functionality is now provided in the Android Design Support Library

This library includes support for

  • Floating labels
  • Floating action button
  • Snackbar
  • Navigation drawer
  • and more

Concatenate in jQuery Selector

There is nothing wrong with syntax of

$('#part' + number).html(text);

jQuery accepts a String (usually a CSS Selector) or a DOM Node as parameter to create a jQuery Object.

In your case you should pass a String to $() that is

$(<a string>)

Make sure you have access to the variables number and text.

To test do:

    alert(number + ":" + text);//or use console.log(number + ":" + text)
    $('#part' + number).html(text);

If you see you dont have access, pass them as parameters to the function, you have to include the uual parameters for $.get and pass the custom parameters after them.

LEFT INNER JOIN vs. LEFT OUTER JOIN - Why does the OUTER take longer?

Wait -- did you actually mean that "the same number of rows ... are being processed" or that "the same number of rows are being returned"? In general, the outer join would process many more rows, including those for which there is no match, even if it returns the same number of records.

How to update core-js to core-js@3 dependency?

With this

npm install --save core-js@^3

you now get the error

"core-js@<3 is no longer maintained and not recommended for usage due to the number of
issues. Please, upgrade your dependencies to the actual version of core-js@3"

so you might want to instead try

npm install --save core-js@3

if you're reading this post June 9 2020.

Singular matrix issue with Numpy

The matrix you pasted

[[   1,    8,   50],
 [   8,   64,  400],
 [  50,  400, 2500]]

Has a determinant of zero. This is the definition of a Singular matrix (one for which an inverse does not exist)

How to put labels over geom_bar for each bar in R with ggplot2

Try this:

ggplot(data=dat, aes(x=Types, y=Number, fill=sample)) + 
     geom_bar(position = 'dodge', stat='identity') +
     geom_text(aes(label=Number), position=position_dodge(width=0.9), vjust=-0.25)

ggplot output

How to use componentWillMount() in React Hooks?

It might be clear for most, but have in mind that a function called inside the function component's body, acts as a beforeRender. This doesn't answer the question of running code on ComponentWillMount (before the first render) but since it is related and might help others I'm leaving it here.

const MyComponent = () => {
  const [counter, setCounter] = useState(0)
  useEffect(() => {
    console.log('after render')

  const iterate = () => {
    setCounter(prevCounter => prevCounter+1)

  const beforeRender = () => {
    console.log('before render')


  return (
      <button onClick={iterate}>Re-render</button>

export default MyComponent

Relative imports - ModuleNotFoundError: No module named x

If you are using python 3+ then try adding below lines

import os, sys
dir_path = os.path.dirname(os.path.realpath(__file__))
parent_dir_path = os.path.abspath(os.path.join(dir_path, os.pardir))
sys.path.insert(0, parent_dir_path)

Sending SOAP request using Python Requests

It is indeed possible.

Here is an example calling the Weather SOAP Service using plain requests lib:

import requests
#headers = {'content-type': 'application/soap+xml'}
headers = {'content-type': 'text/xml'}
body = """<?xml version="1.0" encoding="UTF-8"?>
         <SOAP-ENV:Envelope xmlns:ns0="" xmlns:ns1="" 
            xmlns:xsi="" xmlns:SOAP-ENV="">

response =,data=body,headers=headers)
print response.content

Some notes:

  • The headers are important. Most SOAP requests will not work without the correct headers. application/soap+xml is probably the more correct header to use (but the weatherservice prefers text/xml
  • This will return the response as a string of xml - you would then need to parse that xml.
  • For simplicity I have included the request as plain text. But best practise would be to store this as a template, then you can load it using jinja2 (for example) - and also pass in variables.

For example:

from jinja2 import Environment, PackageLoader
env = Environment(loader=PackageLoader('myapp', 'templates'))
template = env.get_template('soaprequests/WeatherSericeRequest.xml')
body = template.render()

Some people have mentioned the suds library. Suds is probably the more correct way to be interacting with SOAP, but I often find that it panics a little when you have WDSLs that are badly formed (which, TBH, is more likely than not when you're dealing with an institution that still uses SOAP ;) ).

You can do the above with suds like so:

from suds.client import Client
client = Client(url)
print client ## shows the details of this service

result = client.service.GetWeatherInformation() 
print result 

Note: when using suds, you will almost always end up needing to use the doctor!

Finally, a little bonus for debugging SOAP; TCPdump is your friend. On Mac, you can run TCPdump like so:

sudo tcpdump -As 0 

This can be helpful for inspecting the requests that actually go over the wire.

The above two code snippets are also available as gists:

Get all rows from SQLite

This is almost the same solution as the others, but I thought it might be good to look at different ways of achieving the same result and explain a little bit:

Probably you have the table name String variable initialized at the time you called the DBHandler so it would be something like;

private static final String MYDATABASE_TABLE = "anyTableName";

Then, wherever you are trying to retrieve all table rows;

SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from " + MYDATABASE_TABLE, null);

List<String> fileName = new ArrayList<>();
if (cursor.moveToFirst()){

Honestly, there are many ways about doing this,

How do you iterate through every file/directory recursively in standard C++?

If you are on Windows, you can use the FindFirstFile together with FindNextFile API. You can use FindFileData.dwFileAttributes to check if a given path is a file or a directory. If it's a directory, you can recursively repeat the algorithm.

Here, I have put together some code that lists all the files on a Windows machine.

Temporary tables in stored procedures

Nope. Independent instances of the temporary table will be created per each connection.

How to generate classes from wsdl using Maven and wsimport?

The key here is keep option of wsimport. And it is configured using element in About keep from the wsimport documentation :

-keep                     keep generated files

dropping a global temporary table

The DECLARE GLOBAL TEMPORARY TABLE statement defines a temporary table for the current connection.

These tables do not reside in the system catalogs and are not persistent.

Temporary tables exist only during the connection that declared them and cannot be referenced outside of that connection.

When the connection closes, the rows of the table are deleted, and the in-memory description of the temporary table is dropped.

For your reference

Create iOS Home Screen Shortcuts on Chrome for iOS

The is no API for adding a shortcut to the home screen in iOS, so no third-party browser is capable of providing that functionality.

Simple Random Samples from a Sql database

There's a very interesting discussion of this type of issue here:

I think with absolutely no assumptions about the table that your O(n lg n) solution is the best. Though actually with a good optimizer or a slightly different technique the query you list may be a bit better, O(m*n) where m is the number of random rows desired, as it wouldn't necesssarily have to sort the whole large array, it could just search for the smallest m times. But for the sort of numbers you posted, m is bigger than lg n anyway.

Three asumptions we might try out:

  1. there is a unique, indexed, primary key in the table

  2. the number of random rows you want to select (m) is much smaller than the number of rows in the table (n)

  3. the unique primary key is an integer that ranges from 1 to n with no gaps

With only assumptions 1 and 2 I think this can be done in O(n), though you'll need to write a whole index to the table to match assumption 3, so it's not necesarily a fast O(n). If we can ADDITIONALLY assume something else nice about the table, we can do the task in O(m log m). Assumption 3 would be an easy nice additional property to work with. With a nice random number generator that guaranteed no duplicates when generating m numbers in a row, an O(m) solution would be possible.

Given the three assumptions, the basic idea is to generate m unique random numbers between 1 and n, and then select the rows with those keys from the table. I don't have mysql or anything in front of me right now, so in slightly pseudocode this would look something like:

create table RandomKeys (RandomKey int)
create table RandomKeysAttempt (RandomKey int)

-- generate m random keys between 1 and n
for i = 1 to m
  insert RandomKeysAttempt select rand()*n + 1

-- eliminate duplicates
insert RandomKeys select distinct RandomKey from RandomKeysAttempt

-- as long as we don't have enough, keep generating new keys,
-- with luck (and m much less than n), this won't be necessary
while count(RandomKeys) < m
  NextAttempt = rand()*n + 1
  if not exists (select * from RandomKeys where RandomKey = NextAttempt)
    insert RandomKeys select NextAttempt

-- get our random rows
select *
from RandomKeys r
join table t ON r.RandomKey = t.UniqueKey

If you were really concerned about efficiency, you might consider doing the random key generation in some sort of procedural language and inserting the results in the database, as almost anything other than SQL would probably be better at the sort of looping and random number generation required.

jQuery UI DatePicker to show year only

In 2018,

    format: "yyyy",
    weekStart: 1,
    orientation: "bottom",
    language: "{{ app.request.locale }}",
    keyboardNavigation: false,
    viewMode: "years",
    minViewMode: "years"

How do I count unique values inside a list

Use a set:

words = ['a', 'b', 'c', 'a']
unique_words = set(words)             # == set(['a', 'b', 'c'])
unique_word_count = len(unique_words) # == 3

Armed with this, your solution could be as simple as:

words = []
ipta = raw_input("Word: ")

while ipta:
  ipta = raw_input("Word: ")

unique_word_count = len(set(words))

print "There are %d unique words!" % unique_word_count

How to convert a char array to a string?

The string class has a constructor that takes a NULL-terminated C-string:

char arr[ ] = "This is a test";

string str(arr);

//  You can also assign directly to a string.
str = "This is another string";

// or
str = arr;

move a virtual machine from one vCenter to another vCenter

I've figure it out the solution to my problem:

  • Step 1: from within the vSphere client, while connected to vCenter1, select the VM and then from "File" menu select "Export"->"Export OVF Template" (Note: make sure the VM is Powered Off otherwise this feature is not available - it will be gray). This action will allow you to save on your machine/laptop the VM (as an .vmdk, .ovf and a .mf file).
  • Step 2: Connect to the vCenter2 with your vSphere client and from "File" menu select "Deploy OVF Template..." and then select the location where the VM was saved in the previous step.

That was all!

How to get an ASP.NET MVC Ajax response to redirect to new page instead of inserting view into UpdateTargetId?

While not elegant, works for me in certain situations.


if (RedirectToPage)
    return PartialView("JavascriptRedirect", new JavascriptRedirectModel(""));
   ... return regular ajax partialview


    public JavascriptRedirectModel(string location)
        Location = location;

    public string Location { get; set; }


@model Models.Shared.JavascriptRedirectModel

<script type="text/javascript">
    window.location = '@Model.Location';

How to limit google autocomplete results to City and Country only

    <title>Example Using Google Complete API</title>   

   <input id="geocomplete" type="text" placeholder="Type an address/location"/>
   <script src=";libraries=places"></script>
   <script src=""></script>

  <script src=""></script>

For more information visit this link

Disable building workspace process in Eclipse

if needed programmatic from a PDE or JDT code:

public static void setWorkspaceAutoBuild(boolean flag) throws CoreException 
IWorkspace workspace = ResourcesPlugin.getWorkspace();
final IWorkspaceDescription description = workspace.getDescription();

How to make an anchor tag refer to nothing?

React no longer support using a function like this href="javascript:void(0)" in your anchor tag, but here is something that works pretty well.

<a href="#" onClick={() => null} >link</a>

How to escape a JSON string containing newline characters using JavaScript?

this is an old post. but it may still be helpful for those using angular.fromJson, and JSON.stringify. escape() is deprecated. use this instead,

var uri_enc = encodeURIComponent(uri); //before you post the contents
var uri_dec = decodeURIComponent(uri_enc); //before you display/use the contents.


Is log(n!) = T(n·log(n))?

enter image description here

Sorry, I don't know how to use LaTeX syntax on stackoverflow..

How to replace innerHTML of a div using jQuery?

Pure JS and Shortest

Pure JS

regTitle.innerHTML = 'Hello World'

regTitle.innerHTML = 'Hello World';
<div id="regTitle"></div>


$(regTitle).html('Hello World'); 

// note: no quotes around regTitle_x000D_
$(regTitle).html('Hello World'); 
<script src=""></script>_x000D_
<div id="regTitle"></div>

String.equals() with multiple conditions (and one action on result)

if (Arrays.asList("John", "Mary", "Peter").contains(name)) {
  • This is not as fast as using a prepared Set, but it performs no worse than using OR.
  • This doesn't crash when name is NULL (same with Set).
  • I like it because it looks clean

Splitting String and put it on int array

You are doing Integer division, so you will lose the correct length if the user happens to put in an odd number of inputs - that is one problem I noticed. Because of this, when I run the code with an input of '1,2,3,4,5,6,7' my last value is ignored...

Jquery validation plugin - TypeError: $(...).validate is not a function

You didn't include the base jQuery Validation library:

<script src=""></script>

Put that before the additional methods library. (BTW this is a hosted version, download your own if you want)

How do you UDP multicast in Python?

Just another answer to explain some subtle points in the code of the other answers:

  • socket.INADDR_ANY - (Edited) In the context of IP_ADD_MEMBERSHIP, this doesn't really bind the socket to all interfaces but just choose the default interface where multicast is up (according to routing table)
  • Joining a multicast group isn't the same as binding a socket to a local interface address

see What does it mean to bind a multicast (UDP) socket? for more on how multicast works

Multicast receiver:

import socket
import struct
import argparse

def run(groups, port, iface=None, bind_group=None):
    # generally speaking you want to bind to one of the groups you joined in
    # this script,
    # but it is also possible to bind to group which is added by some other
    # programs (like another python program instance of this)

    # assert bind_group in groups + [None], \
    #     'bind group not in groups to join'
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)

    # allow reuse of socket (to allow another instance of python running this
    # script binding to the same ip/port)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    sock.bind(('' if bind_group is None else bind_group, port))
    for group in groups:
        mreq = struct.pack(
            '4sl' if iface is None else '4s4s',
            socket.INADDR_ANY if iface is None else socket.inet_aton(iface))

        sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)

    while True:

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--port', type=int, default=19900)
    parser.add_argument('--join-mcast-groups', default=[], nargs='*',
                        help='multicast groups (ip addrs) to listen to join')
        '--iface', default=None,
        help='local interface to use for listening to multicast data; '
        'if unspecified, any interface would be chosen')
        '--bind-group', default=None,
        help='multicast groups (ip addrs) to bind to for the udp socket; '
        'should be one of the multicast groups joined globally '
        '(not necessarily joined in this python program) '
        'in the interface specified by --iface. '
        'If unspecified, bind to '
        '(all addresses (all multicast addresses) of that interface)')
    args = parser.parse_args()
    run(args.join_mcast_groups, args.port, args.iface, args.bind_group)

sample usage: (run the below in two consoles and choose your own --iface (must be same as the interface that receives the multicast data))

python3 --iface='' --join-mcast-groups '' '' '' --bind-group ''

python3 --iface='' --join-mcast-groups ''

Multicast sender:

import socket
import argparse

def run(group, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, MULTICAST_TTL)
    sock.sendto(b'from ' +
                f'group: {group}, port: {port}'.encode(), (group, port))

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--mcast-group', default='')
    parser.add_argument('--port', default=19900)
    args = parser.parse_args()
    run(args.mcast_group, args.port)

sample usage: # assume the receiver binds to the below multicast group address and that some program requests to join that group. And to simplify the case, assume the receiver and the sender are under the same subnet

python3 --mcast-group ''

python3 --mcast-group ''

failed to resolve and

Are you import them? Like this:

compile ''
compile ''

Passing a method as a parameter in Ruby

You have to call the method "call" of the function object:

weight = dist )

EDIT: as explained in the comments, this approach is wrong. It would work if you're using Procs instead of normal functions.

Call static methods from regular ES6 class methods

Both ways are viable, but they do different things when it comes to inheritance with an overridden static method. Choose the one whose behavior you expect:

class Super {
  static whoami() {
    return "Super";
  lognameA() {
  lognameB() {
class Sub extends Super {
  static whoami() {
    return "Sub";
new Sub().lognameA(); // Super
new Sub().lognameB(); // Sub

Referring to the static property via the class will be actually static and constantly give the same value. Using this.constructor instead will use dynamic dispatch and refer to the class of the current instance, where the static property might have the inherited value but could also be overridden.

This matches the behavior of Python, where you can choose to refer to static properties either via the class name or the instance self.

If you expect static properties not to be overridden (and always refer to the one of the current class), like in Java, use the explicit reference.

Java : Sort integer array without using Arrays.sort()

This will surely help you.

int n[] = {4,6,9,1,7};

    for(int i=n.length;i>=0;i--){
        for(int j=0;j<n.length-1;j++){
            if(n[j] > n[j+1]){

private static void swapNumbers(int i, int j, int[] array) {

    int temp;
    temp = array[i];
    array[i] = array[j];
    array[j] = temp;

private static void printNumbers(int[] input) {

    for (int i = 0; i < input.length; i++) {
        System.out.print(input[i] + ", ");

Could not load file or assembly 'System.Net.Http.Formatting' or one of its dependencies. The system cannot find the path specified

I was facing the same problem because


version written inside webconfig was 5.0.3 but inside the bin folder the library System.Net.Http.Formatting dll version was 4.0.2

so I just replaced with the same given inside bin

enter image description here

enter image description here

just do this clean project and build

How to automatically allow blocked content in IE?

Alternatively, as long as permissions are not given, the good old <noscript> tags works. You can cover the page in css and tell them what's wrong, ... without using javascript ofcourse.

ScrollIntoView() causing the whole page to move

Using Brilliant's idea, here's a solution that only (vertically) scrolls if the element is NOT currently visible. The idea is to get the bounding box of the viewport and the element to be displayed in browser-window coordinate space. Check if it's visible and if not, scroll by the required distance so the element is shown at the top or bottom of the viewport.

    function ensure_visible(element_id)
        // adjust these two to match your HTML hierarchy
        var element_to_show  = document.getElementById(element_id);
        var scrolling_parent = element_to_show.parentElement;

        var top = parseInt(scrolling_parent.getBoundingClientRect().top);
        var bot = parseInt(scrolling_parent.getBoundingClientRect().bottom);

        var now_top = parseInt(element_to_show.getBoundingClientRect().top);
        var now_bot = parseInt(element_to_show.getBoundingClientRect().bottom);

        // console.log("Element: "+now_top+";"+(now_bot)+" Viewport:"+top+";"+(bot) );

        var scroll_by = 0;
        if(now_top < top)
            scroll_by = -(top - now_top);
        else if(now_bot > bot)
            scroll_by = now_bot - bot;
        if(scroll_by != 0)
            scrolling_parent.scrollTop += scroll_by; // tr.offsetTop;

How to exit if a command failed?

Using exit directly may be tricky as the script may be sourced from other places (e.g. from terminal). I prefer instead using subshell with set -e (plus errors should go into cerr, not cout) :

set -e
my_command || ERRCODE=$?
test $ERRCODE == 0 ||
    (>&2 echo "My command failed ($ERRCODE)"; exit $ERRCODE)

node.js hash string?

function md5(a) {
    var r = 0,
        c = "";
    return h(a);

    function h(t) {
        return u(l(m(t)))

    function l(t) {
        return p(g(f(t), 8 * t.length))

    function u(t) {
        for (var e, i = r ? "0123456789ABCDEF" : "0123456789abcdef", n = "", o = 0; o < t.length; o++)
            e = t.charCodeAt(o),
            n += i.charAt(e >>> 4 & 15) + i.charAt(15 & e);
        return n

    function m(t) {
        for (var e, i, n = "", o = -1; ++o < t.length;)
            e = t.charCodeAt(o),
            i = o + 1 < t.length ? t.charCodeAt(o + 1) : 0,
            55296 <= e && e <= 56319 && 56320 <= i && i <= 57343 && (e = 65536 + ((1023 & e) << 10) + (1023 & i),
            e <= 127 ? n += String.fromCharCode(e) : e <= 2047 ? n += String.fromCharCode(192 | e >>> 6 & 31, 128 | 63 & e) : e <= 65535 ? n += String.fromCharCode(224 | e >>> 12 & 15, 128 | e >>> 6 & 63, 128 | 63 & e) : e <= 2097151 && (n += String.fromCharCode(240 | e >>> 18 & 7, 128 | e >>> 12 & 63, 128 | e >>> 6 & 63, 128 | 63 & e));
        return n

    function f(t) {
        for (var e = Array(t.length >> 2), i = 0; i < e.length; i++)
            e[i] = 0;
        for (i = 0; i < 8 * t.length; i += 8)
            e[i >> 5] |= (255 & t.charCodeAt(i / 8)) << i % 32;
        return e

    function p(t) {
        for (var e = "", i = 0; i < 32 * t.length; i += 8)
            e += String.fromCharCode(t[i >> 5] >>> i % 32 & 255);
        return e

    function g(t, e) {
        t[e >> 5] |= 128 << e % 32,
            t[14 + (e + 64 >>> 9 << 4)] = e;
        for (var i = 1732584193, n = -271733879, o = -1732584194, s = 271733878, a = 0; a < t.length; a += 16) {
            var r = i,
                c = n,
                h = o,
                l = s;
            n = E(n = E(n = E(n = E(n = N(n = N(n = N(n = N(n = C(n = C(n = C(n = C(n = S(n = S(n = S(n = S(n, o = S(o, s = S(s, i = S(i, n, o, s, t[a + 0], 7, -680876936), n, o, t[a + 1], 12, -389564586), i, n, t[a + 2], 17, 606105819), s, i, t[a + 3], 22, -1044525330), o = S(o, s = S(s, i = S(i, n, o, s, t[a + 4], 7, -176418897), n, o, t[a + 5], 12, 1200080426), i, n, t[a + 6], 17, -1473231341), s, i, t[a + 7], 22, -45705983), o = S(o, s = S(s, i = S(i, n, o, s, t[a + 8], 7, 1770035416), n, o, t[a + 9], 12, -1958414417), i, n, t[a + 10], 17, -42063), s, i, t[a + 11], 22, -1990404162), o = S(o, s = S(s, i = S(i, n, o, s, t[a + 12], 7, 1804603682), n, o, t[a + 13], 12, -40341101), i, n, t[a + 14], 17, -1502002290), s, i, t[a + 15], 22, 1236535329), o = C(o, s = C(s, i = C(i, n, o, s, t[a + 1], 5, -165796510), n, o, t[a + 6], 9, -1069501632), i, n, t[a + 11], 14, 643717713), s, i, t[a + 0], 20, -373897302), o = C(o, s = C(s, i = C(i, n, o, s, t[a + 5], 5, -701558691), n, o, t[a + 10], 9, 38016083), i, n, t[a + 15], 14, -660478335), s, i, t[a + 4], 20, -405537848), o = C(o, s = C(s, i = C(i, n, o, s, t[a + 9], 5, 568446438), n, o, t[a + 14], 9, -1019803690), i, n, t[a + 3], 14, -187363961), s, i, t[a + 8], 20, 1163531501), o = C(o, s = C(s, i = C(i, n, o, s, t[a + 13], 5, -1444681467), n, o, t[a + 2], 9, -51403784), i, n, t[a + 7], 14, 1735328473), s, i, t[a + 12], 20, -1926607734), o = N(o, s = N(s, i = N(i, n, o, s, t[a + 5], 4, -378558), n, o, t[a + 8], 11, -2022574463), i, n, t[a + 11], 16, 1839030562), s, i, t[a + 14], 23, -35309556), o = N(o, s = N(s, i = N(i, n, o, s, t[a + 1], 4, -1530992060), n, o, t[a + 4], 11, 1272893353), i, n, t[a + 7], 16, -155497632), s, i, t[a + 10], 23, -1094730640), o = N(o, s = N(s, i = N(i, n, o, s, t[a + 13], 4, 681279174), n, o, t[a + 0], 11, -358537222), i, n, t[a + 3], 16, -722521979), s, i, t[a + 6], 23, 76029189), o = N(o, s = N(s, i = N(i, n, o, s, t[a + 9], 4, -640364487), n, o, t[a + 12], 11, -421815835), i, n, t[a + 15], 16, 530742520), s, i, t[a + 2], 23, -995338651), o = E(o, s = E(s, i = E(i, n, o, s, t[a + 0], 6, -198630844), n, o, t[a + 7], 10, 1126891415), i, n, t[a + 14], 15, -1416354905), s, i, t[a + 5], 21, -57434055), o = E(o, s = E(s, i = E(i, n, o, s, t[a + 12], 6, 1700485571), n, o, t[a + 3], 10, -1894986606), i, n, t[a + 10], 15, -1051523), s, i, t[a + 1], 21, -2054922799), o = E(o, s = E(s, i = E(i, n, o, s, t[a + 8], 6, 1873313359), n, o, t[a + 15], 10, -30611744), i, n, t[a + 6], 15, -1560198380), s, i, t[a + 13], 21, 1309151649), o = E(o, s = E(s, i = E(i, n, o, s, t[a + 4], 6, -145523070), n, o, t[a + 11], 10, -1120210379), i, n, t[a + 2], 15, 718787259), s, i, t[a + 9], 21, -343485551),
                i = v(i, r),
                n = v(n, c),
                o = v(o, h),
                s = v(s, l)
        return [i, n, o, s]

    function _(t, e, i, n, o, s) {
        return v((a = v(v(e, t), v(n, s))) << (r = o) | a >>> 32 - r, i);
        var a, r

    function S(t, e, i, n, o, s, a) {
        return _(e & i | ~e & n, t, e, o, s, a)

    function C(t, e, i, n, o, s, a) {
        return _(e & n | i & ~n, t, e, o, s, a)

    function N(t, e, i, n, o, s, a) {
        return _(e ^ i ^ n, t, e, o, s, a)

    function E(t, e, i, n, o, s, a) {
        return _(i ^ (e | ~n), t, e, o, s, a)

    function v(t, e) {
        var i = (65535 & t) + (65535 & e);
        return (t >> 16) + (e >> 16) + (i >> 16) << 16 | 65535 & i
string = 'hello';

How to use setArguments() and getArguments() methods in Fragments?

Instantiating the Fragment the correct way!

getArguments() setArguments() methods seem very useful when it comes to instantiating a Fragment using a static method.
ie Myfragment.createInstance(String msg)

How to do it?

Fragment code

public MyFragment extends Fragment {

    private String displayMsg;
    private TextView text;

    public static MyFragment createInstance(String displayMsg)
        MyFragment fragment = new MyFragment();
        Bundle args = new Bundle();
        fragment.setArguments(args);           //set
        return fragment;

    public void onCreate(Bundle bundle)
        displayMsg = getArguments().getString("KEY"):    // get 

    public View onCreateView(LayoutInlater inflater, ViewGroup parent, Bundle bundle){
        View view = inflater.inflate(,parent,false);
        text = (TextView)view.findViewById(;
        text.setText(displayMsg)    // show msg
        returm view;


Let's say you want to pass a String while creating an Instance. This is how you will do it.

MyFragment.createInstance("This String will be shown in textView");

Read More

1) Why Myfragment.getInstance(String msg) is preferred over new MyFragment(String msg)?
2) Sample code on Fragments

What does a Status of "Suspended" and high DiskIO means from sp_who2?

This is a very broad question, so I am going to give a broad answer.

  1. A query gets suspended when it is requesting access to a resource that is currently not available. This can be a logical resource like a locked row or a physical resource like a memory data page. The query starts running again, once the resource becomes available. 
  2. High disk IO means that a lot of data pages need to be accessed to fulfill the request.

That is all that I can tell from the above screenshot. However, if I were to speculate, you probably have an IO subsystem that is too slow to keep up with the demand. This could be caused by missing indexes or an actually too slow disk. Keep in mind, that 15000 reads for a single OLTP query is slightly high but not uncommon.

When to use malloc for char pointers

Use malloc() when you don't know the amount of memory needed during compile time. In case if you have read-only strings then you can use const char* str = "something"; . Note that the string is most probably be stored in a read-only memory location and you'll not be able to modify it. On the other hand if you know the string during compiler time then you can do something like: char str[10]; strcpy(str, "Something"); Here the memory is allocated from stack and you will be able to modify the str. Third case is allocating using malloc. Lets say you don'r know the length of the string during compile time. Then you can do char* str = malloc(requiredMem); strcpy(str, "Something"); free(str);

Removing a list of characters in string

''.join(c for c in myString if not c in badTokens)

How to pass an event object to a function in Javascript?

  1. Modify the definition of the function check_me as::

     function check_me(ev) {
  2. Now you can access the methods and parameters of the event, in your case:

  3. Then, you have to pass the parameter on the onclick in the inline call::

     <button type="button" onclick="check_me(event);">Click Me!</button>

A useful link to understand this.

Full example:

<!DOCTYPE html>
<html lang="en">
    <script type="text/javascript">
      function check_me(ev) {
        alert("Hello World!")
    <button type="button" onclick="check_me(event);">Click Me!</button>

Alternatives (best practices):

Although the above is the direct answer to the question (passing an event object to an inline event), there are other ways of handling events that keep the logic separated from the presentation

A. Using addEventListener:

<!DOCTYPE html>
<html lang="en">
    <button id='my_button' type="button">Click Me!</button>

    <!-- put the javascript at the end to guarantee that the DOM is ready to use-->
    <script type="text/javascript">
      function check_me(ev) {
        alert("Hello World!")
      <!-- add the event to the button identified #my_button -->
      document.getElementById("my_button").addEventListener("click", check_me);

B. Isolating Javascript:

Both of the above solutions are fine for a small project, or a hackish quick and dirty solution, but for bigger projects, it is better to keep the HTML separated from the Javascript.

Just put this two files in the same folder:

  • example.html:
<!DOCTYPE html>
<html lang="en">
    <button id='my_button' type="button">Click Me!</button>

    <!-- put the javascript at the end to guarantee that the DOM is ready to use-->
    <script type="text/javascript" src="example.js"></script>
  • example.js:
function check_me(ev) {
    alert("Hello World!")
document.getElementById("my_button").addEventListener("click", check_me);

Find a file in python

If you are working with Python 2 you have a problem with infinite recursion on windows caused by self-referring symlinks.

This script will avoid following those. Note that this is windows-specific!

import os
from scandir import scandir
import ctypes

def is_sym_link(path):
    return os.path.isdir(path) and (ctypes.windll.kernel32.GetFileAttributesW(unicode(path)) & FILE_ATTRIBUTE_REPARSE_POINT)

def find(base, filenames):
    hits = []

    def find_in_dir_subdir(direc):
        content = scandir(direc)
        for entry in content:
            if in filenames:

            elif entry.is_dir() and not is_sym_link(os.path.join(direc,
                except UnicodeDecodeError:
                    print "Could not resolve " + os.path.join(direc,

    if not os.path.exists(base):

    return hits

It returns a list with all paths that point to files in the filenames list. Usage:

find("C:\\", ["", "", "", "", ""])

How to enumerate a range of numbers starting at 1

>>> list(enumerate(range(1999, 2005)))[1:]
[(1, 2000), (2, 2001), (3, 2002), (4, 2003), (5, 2004)]

How to repair a serialized string which has been corrupted by an incorrect byte count length?

After having tried some things on this page without success I had a look in the page-source and remarked that all quotes in the serialized string have been replaced by html-entities. Decoding these entities helps avoiding much headache:

$myVar = html_entity_decode($myVar);

How is returning the output of a function different from printing it?

Unfortunately, there is a character limit so this will be in many parts. First thing to note is that return and print are statements, not functions, but that is just semantics.

I’ll start with a basic explanation. print just shows the human user a string representing what is going on inside the computer. The computer cannot make use of that printing. return is how a function gives back a value. This value is often unseen by the human user, but it can be used by the computer in further functions.

On a more expansive note, print will not in any way affect a function. It is simply there for the human user’s benefit. It is very useful for understanding how a program works and can be used in debugging to check various values in a program without interrupting the program.

return is the main way that a function returns a value. All functions will return a value, and if there is no return statement (or yield but don’t worry about that yet), it will return None. The value that is returned by a function can then be further used as an argument passed to another function, stored as a variable, or just printed for the benefit of the human user. Consider these two programs:

def function_that_prints():
    print "I printed"

def function_that_returns():
    return "I returned"

f1 = function_that_prints()
f2 = function_that_returns()

print "Now let us see what the values of f1 and f2 are"

print f1 --->None

print f2---->"I returned"

When function_that_prints ran, it automatically printed to the console "I printed". However, the value stored in f1 is None because that function had no return statement.

When function_that_returns ran, it did not print anything to the console. However, it did return a value, and that value was stored in f2. When we printed f2 at the end of the code, we saw "I returned"

How to generate a GUID in Oracle?

It is not clear what you mean by auto-generate a guid into an insert statement but at a guess, I think you are trying to do something like the following:


In that case I believe the ID column should be declared as RAW(16);

I am doing this off the top of my head. I don't have an Oracle instance handy to test against, but I think that is what you want.

javascript regular expression to not match a word

This can be done in 2 ways:

if (str.match(/abc|def/)) {

if (/abc|def/.test(str)) {

What causes a SIGSEGV

There are various causes of segmentation faults, but fundamentally, you are accessing memory incorrectly. This could be caused by dereferencing a null pointer, or by trying to modify readonly memory, or by using a pointer to somewhere that is not mapped into the memory space of your process (that probably means you are trying to use a number as a pointer, or you incremented a pointer too far). On some machines, it is possible for a misaligned access via a pointer to cause the problem too - if you have an odd address and try to read an even number of bytes from it, for example (that can generate SIGBUS, instead).

How to use unicode characters in Windows command line?

Actually, the trick is that the command prompt actually understands these non-english characters, just can't display them correctly.

When I enter a path in the command prompt that contains some non-english chracters it is displayed as "?? ?????? ?????". When you submit your command (cd "??? ?????? ?????" in my case), everything is working as expected.

Can't connect to local MySQL server through socket homebrew

Looks like your mysql server is not started. I usually run the stop command and then start it again:

mysqld stop
mysql.server start

Same error, and this works for me.

Reading a .txt file using Scanner class in Java

At first check the file address, it must be beside your .java file or in any address that you define in classpath environment variable. When you check this then try below.

  1. you must use a file name by it's extension in File object constructor, as an example:

    File myFile = new File("test.txt");

  2. but there is a better way to use it inside Scanner object by pass the filename absolute address, as an example:

    Scanner sc = new Scanner(Paths.get("test.txt"));

in this way you must import java.nio.file.Paths as well.

Why is this jQuery click function not working?

I found the best solution for this problem by using ON with $(document).

 $(document).on('click', '#yourid', function() { alert("hello"); });

for id start with see below:

$(document).on('click', 'div[id^="start"]', function() {
alert ('hello'); });

finally after 1 week I not need to add onclick triger. I hope this will help many people

Restore DB — Error RESTORE HEADERONLY is terminating abnormally.

I think you have 2 separate problems, 1. with restoring and 2. with creating

For 1. you could try checking to see if the file was transferred properly (one easy way would be to check the md5 of the file on the server and again on the local environment to see if they match).

How to combine GROUP BY and ROW_NUMBER?

Wow, the other answers look complex - so I'm hoping I've not missed something obvious.

You can use OVER/PARTITION BY against aggregates, and they'll then do grouping/aggregating without a GROUP BY clause. So I just modified your query to:

select T2.ID AS T2ID
    ,T2.Name as T2Name
    ,T1.ID AS T1ID
    ,T1.Name As T1Name
FROM @t2 T2
    SELECT Rel.t2ID
 --       ,MAX(Rel.t1ID)AS t1ID 
-- the MAX returns an arbitrary ID, what i need is: 
      ,ROW_NUMBER()OVER(Partition By Rel.t2ID Order By Price DESC)As PriceList
        ,SUM(Price)OVER(PARTITION BY Rel.t2ID) AS Price
        FROM @t1 T1 
        INNER JOIN @relation Rel ON Rel.t1ID=T1.ID
--        GROUP BY Rel.t2ID
)AS T1Sum ON  T1Sum.t2ID = T2.ID
where t1Sum.PriceList = 1

Which gives the requested result set.

Using PowerShell to write a file in UTF-8 without the BOM

I figured this wouldn't be UTF, but I just found a pretty simple solution that seems to work...

Get-Content path/to/file.ext | out-file -encoding ASCII targetFile.ext

For me this results in a utf-8 without bom file regardless of the source format.

What does ||= (or-equals) mean in Ruby?

a ||= b is a conditional assignment operator. It means if a is undefined or falsey, then evaluate b and set a to the result. Equivalently, if a is defined and evaluates to truthy, then b is not evaluated, and no assignment takes place. For example:

a ||= nil # => nil
a ||= 0 # => 0
a ||= 2 # => 0

foo = false # => false
foo ||= true # => true
foo ||= false # => true

Confusingly, it looks similar to other assignment operators (such as +=), but behaves differently.

  • a += b translates to a = a + b
  • a ||= b roughly translates to a || a = b

It is a near-shorthand for a || a = b. The difference is that, when a is undefined, a || a = b would raise NameError, whereas a ||= b sets a to b. This distinction is unimportant if a and b are both local variables, but is significant if either is a getter/setter method of a class.

Further reading:

Select all elements with a "data-xxx" attribute without using jQuery


will get you all elements with that attribute.


will only get you ones with a value of 1.

Using git to get just the latest revision

Alternate solution to doing shallow clone (git clone --depth=1 <URL>) would be, if remote side supports it, to use --remote option of git archive:

$ git archive --format=tar --remote=<repository URL> HEAD | tar xf -

Or, if remote repository in question is browse-able using some web interface like gitweb or GitHub, then there is a chance that it has 'snapshot' feature, and you can download latest version (without versioning information) from web interface.

Google Play app description formatting

Another alternative to cut, copy and paste emojis is:

how to install Lex and Yacc in Ubuntu?

Use the synaptic packet manager in order to install yacc / lex. If you are feeling more comfortable doing this on the console just do:

sudo apt-get install bison flex

There are some very nice articles on the net on how to get started with those tools. I found the article from CodeProject to be quite good and helpful (see here). But you should just try and search for "introduction to lex", there are plenty of good articles showing up.

How to set different colors in HTML in one statement?

Use the span tag


<span class="redText">My Name is:</span>&nbsp;<span class="blackText">Tintincute</span>

It's also a good idea to avoid inline styling. Use a custom CSS class instead.

Postman Chrome: What is the difference between form-data, x-www-form-urlencoded and raw

These are different Form content types defined by W3C. If you want to send simple text/ ASCII data, then x-www-form-urlencoded will work. This is the default.

But if you have to send non-ASCII text or large binary data, the form-data is for that.

You can use Raw if you want to send plain text or JSON or any other kind of string. Like the name suggests, Postman sends your raw string data as it is without modifications. The type of data that you are sending can be set by using the content-type header from the drop down.

Binary can be used when you want to attach non-textual data to the request, e.g. a video/audio file, images, or any other binary data file.

Refer to this link for further reading: Forms in HTML documents

How to get featured image of a product in woocommerce

I had the same problem and solved it by using the default woocommerce hook to display the product image.

while ( $loop->have_posts() ) : $loop->the_post();
   echo woocommerce_get_product_thumbnail('woocommerce_full_size');

Available parameters:

  • woocommerce_thumbnail
  • woocommerce_full_size

Read url to string in few lines of java code

Now that some time has passed since the original answer was accepted, there's a better approach:

String out = new Scanner(new URL("").openStream(), "UTF-8").useDelimiter("\\A").next();

If you want a slightly fuller implementation, which is not a single line, do this:

public static String readStringFromURL(String requestURL) throws IOException
    try (Scanner scanner = new Scanner(new URL(requestURL).openStream(),
        return scanner.hasNext() ? : "";

Passing string to a function in C - with or without pointers?

Assuming that you meant to write

char *functionname(char *string[256])

Here you are declaring a function that takes an array of 256 pointers to char as argument and returns a pointer to char. Here, on the other hand,

char functionname(char string[256])

You are declaring a function that takes an array of 256 chars as argument and returns a char.

In other words the first function takes an array of strings and returns a string, while the second takes a string and returns a character.

Weird PHP error: 'Can't use function return value in write context'


instead of:

if (empty(get_option('smth')))

should be:

if (!get_option('smth'))

Output grep results to text file, need cleaner output

grep -n "YOUR SEARCH STRING" * > output-file

The -n will print the line number and the > will redirect grep-results to the output-file.
If you want to "clean" the results you can filter them using pipe | for example:
grep -n "test" * | grep -v "mytest" > output-file will match all the lines that have the string "test" except the lines that match the string "mytest" (that's the switch -v) - and will redirect the result to an output file.
A few good grep-tips can be found on this post

Can I escape a double quote in a verbatim string literal?

Use double quotation marks.

string foo = @"this ""word"" is escaped";

How to run mysql command on bash?

This one worked, double quotes when $user and $password are outside single quotes. Single quotes when inside a single quote statement.

mysql --user="$user" --password="$password" --database="$user" --execute='DROP DATABASE '$user'; CREATE DATABASE '$user';'

How to remove RVM (Ruby Version Manager) from my system

I am running Ubuntu 19.04 and followed all the instructions above and then some. Finally, what worked for me was to run

sudo apt autoremove rvm

and now when I try and reinstall RVM it's actually gone. RVM is invasive, to say the least.

How do I fix a "Performance counter registry hive consistency" when installing SQL Server R2 Express?

I had this same problem. For me this solution worked for SQL Server 2008 R2 Express.

  1. Create a shortcut for SQLEXPRWT_x64_ENU.exe (This is the name of the file I used)
  2. Right-click on the shortcut and click "Properties"
  3. Look for a box under the shortcut tab that says "Target"
  4. Inside of the target box, add to whatever is already in there this line:

/Action=install /SKIPRULES=PerfMonCounterNotCorruptedCheck

Of course this does not fix the underlying issue but it is a workaround because this fix also works on the principle of skipping the Performance counter check in the setup. The difference is this method worked for me when doing it through the command line failed.

Correct way to handle conditional styling in React

I came across this question while trying to answer the same question. McCrohan's approach with the classes array & join is solid.

Through my experience, I have been working with a lot of legacy ruby code that is being converted to React and as we build the component(s) up I find myself reaching out for both existing css classes and inline styles.

example snippet inside a component:

// if failed, progress bar is red, otherwise green 
    className={`progress-bar ${failed ? failed' : ''}`}
    style={{ width: this.getPercentage() }} 

Again, I find myself reaching out to legacy css code, "packaging" it with the component and moving on.

So, I really feel that it is a bit in the air as to what is "best" as that label will vary greatly depending on your project.

How to display default text "--Select Team --" in combo box on pageload in WPF?

The easiest way I've found to do this is:

<ComboBox Name="MyComboBox"
 Text="-- Select Team --" />

You'll obviously need to add your other options, but this is probably the simplest way to do it.

There is however one downside to this method which is while the text inside your combo box will not be editable, it is still selectable. However, given the poor quality and complexity of every alternative I've found to date, this is probably the best option out there.

Format cell if cell contains date less than today

Your first problem was you weren't using your compare symbols correctly.

< less than
> greater than
<= less than or equal to
>= greater than or equal to

To answer your other questions; get the condition to work on every cell in the column and what about blanks?

What about blanks?

Add an extra IF condition to check if the cell is blank or not, if it isn't blank perform the check. =IF(B2="","",B2<=TODAY())

Condition on every cell in column

enter image description here

how to change the default positioning of modal in bootstrap?

To change the Modal position in the viewport you can target the Modal div id, in this example this id is myModal3

    <div id="modal3" class="modal">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
        <h4 class="modal-title">Modal title</h4>
      <div class="modal-body">
        <p>One fine body…</p>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>

#myModal3 {
outline: none;

How to generate random number in Bash?

Reading from /dev/random or /dev/urandom character special files is the way to go.

These devices return truly random numbers when read and are designed to help application software choose secure keys for encryption. Such random numbers are extracted from an entropy pool that is contributed by various random events. {LDD3, Jonathan Corbet, Alessandro Rubini, and Greg Kroah-Hartman]

These two files are interface to kernel randomization, in particular

void get_random_bytes_arch(void* buf, int nbytes)

which draws truly random bytes from hardware if such function is by hardware implemented (usually is), or it draws from entropy pool (comprised of timings between events like mouse and keyboard interrupts and other interrupts that are registered with SA_SAMPLE_RANDOM).

dd if=/dev/urandom count=4 bs=1 | od -t d

This works, but writes unneeded output from dd to stdout. The command below gives just the integer I need. I can even get specified number of random bits as I need by adjustment of the bitmask given to arithmetic expansion:

me@mymachine:~/$ x=$(head -c 1 /dev/urandom > tmp && hexdump 
                         -d tmp | head -n 1 | cut -c13-15) && echo $(( 10#$x & 127 ))

Right way to split an std::string into a vector<string>

I write this custom function this will help you. But make discussions about the Time complexity.

std::vector<std::string> words;
std::string s;
std::string separator = ",";

while(s.find(separator) != std::string::npos){
   separatorIndex = s.find(separator)
   vtags.push_back(s.substr(0, separatorIndex ));
   words= s.substr(separatorIndex + 1, s.length());


ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

One possibility that I haven't seen widely discussed is that there may be a problem resolving the hostname on the host machine itself. If there is no entry for $(hostname) in /etc/hosts, the Oracle listener gets confused and wont come up.

That turned out to be my problem, and adding the hostname and ip address in /etc/hosts resolved the problem.

Can I have an IF block in DOS batch file?

I ran across this article in the results returned by a search related to the IF command in a batch file, and I couldn't resist the opportunity to correct the misconception that IF blocks are limited to single commands. Following is a portion of a production Windows NT command script that runs daily on the machine on which I am composing this reply.

    if "%COPYTOOL%" equ "R" (
    WWLOGGER.exe "%APPDATA%\WizardWrx\%~n0.LOG" "Using RoboCopy to make a backup of %USERPROFILE%\My Documents\Outlook Files\*"
    %TOOLPATH% %SRCEPATH% %DESTPATH% /copyall %RCLOGSTR% /m /np /r:0 /tee
    C:\BIN\ExitCodeMapper.exe C:\BIN\ExitCodeMapper.INI[Robocopy] %TEMP%\%~n0.TMP %ERRORLEVEL%
) else (
    WWLOGGER.exe "%APPDATA%\WizardWrx\%~n0.LOG" "Using XCopy to make a backup of %USERPROFILE%\My Documents\Outlook Files\*"
    call %TOOLPATH%  "%USERPROFILE%\My Documents\Outlook Files\*" "%USERPROFILE%\My Documents\Outlook Files\_backups" /f /m /v /y
    C:\BIN\ExitCodeMapper.exe C:\BIN\ExitCodeMapper.INI[Xcopy] %TEMP%\%~n0.TMP %ERRORLEVEL%

Perhaps blocks of two or more lines applies exclusively to Windows NT command scripts (.CMD files), because a search of the production scripts directory of an application that is restricted to old school batch (.BAT) files, revealed only one-command blocks. Since the application has gone into extended maintenance (meaning that I am not actively involved in supporting it), I can't say whether that is because I didn't need more than one line, or that I couldn't make them work.

Regardless, if the latter is true, there is a simple workaround; move the multiple lines into either a separate batch file or a batch file subroutine. I know that the latter works in both kinds of scripts.

How to create a scrollable Div Tag Vertically?

This code creates a nice vertical scrollbar for me in Firefox and Chrome:

#answerform {
  position: absolute;
  border: 5px solid gray;
  padding: 5px;
  background: white;
  width: 300px;
  height: 400px;
  overflow-y: scroll;
<div id='answerform'>
  badger<br><br>badger<br><br>badger<br><br>badger<br><br>badger<br><br> mushroom
  <br><br>mushroom<br><br> a badger<br><br>badger<br><br>badger<br><br>badger<br><br>badger<br><br>

Here is a JS fiddle demo proving the above works.

Avoiding NullPointerException in Java

The Google collections framework offers a good and elegant way to achieve the null check.

There is a method in a library class like this:

static <T> T checkNotNull(T e) {
   if (e == null) {
      throw new NullPointerException();
   return e;

And the usage is (with import static):

void foo(int a, Person p) {
   if (checkNotNull(p).getAge() > a) {
   else {

Or in your example:


What are the dark corners of Vim your mom never told you about?

Some of my must-haves are:

cscope + ctags + vim, which can be found on the web.

Some abreviations for quickly starting new code files such as:

ab cpph #include <iostream><CR>#include <string><CR>#include <cstdlib><CR>#include <cassert><CR>#include <vector><CR>#include <
stdexcept><CR>using namespace std;<CR>int main(int argc, char *argv[]) {
ab perlh #!/usr/bin/perl<CR>use strict;<CR>use warnings;<CR>
ab chdr #include <stdio.h><CR>#include <sys/types.h><CR>#include <unistd.h><CR>#include <stdlib.h><CR>#include <sys/stat.h><CR>
#include <sys/wait.h><CR>#include <string.h><CR>int main(int argc, char *argv[]) {
ab xhtmlhdr <?xml version="1.0" encoding="UTF-8"?><CR><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.o
rg/TR/xhtml1/DTD/xhtml1-strict.dtd"><CR><html xmlns=""><CR>  <head><CR>  <title></title><CR><link h
ref="style.css" rel="STYLESHEET" type="text/css"><CR></head>

For example cpph will insert a basic skeleton of a file

There is also my mapping of the function keys:

map <F1> <Esc>:w<CR>:perl $e = `./`; my ($f,$l,@w) = split(":",$e); my $w=join(":",@w); $curwin->Cursor($l,0); VIM::Msg($w);<CR>
map <F2> :wincmd w<CR>
map <F3> :wincmd s<CR>
map <F4> :wincmd v<CR>
map <F5> :wincmd o<CR>
map <F6> :sball<CR>
map <F7> :wq<CR>
map <F8> :wincmd q<CR>
map <F9> :wincmd -<CR>
map <F10> :wincmd +<CR>
map <F11> :wincmd <<CR>
map <F12> :wincmd ><CR>

In this case my F1 is mapped to put the cursor over the next error that needs to be corrected for a source code migration.

map _ ebi"^[ea"^[

This map would make _ quote a string

Is mathematics necessary for programming?

See also Is Programmng == Math? from stackoverflow.

While I don't think it's required for programming, I can't tell you how many times I've been able to use linear algebra concepts to write a clear and short solution to replace a convoluted (and sometimes incorrect) one. When dong any graphics or geometry (and even some solver) work, knowledge of matrices and how to work with them has also been extremely useful.

Python: list of lists

Time traveller here

List_of_list =[([z for z in range(x-2,x+1) if z >= 0],y) for y in range(10) for x in range(10)]

This should do the trick. And the output is this:

[([0], 0), ([0, 1], 0), ([0, 1, 2], 0), ([1, 2, 3], 0), ([2, 3, 4], 0),  ([3, 4, 5], 0), ([4, 5, 6], 0), ([5, 6, 7], 0), ([6, 7, 8], 0), ([7, 8, 9], 0), ([0], 1), ([0, 1], 1), ([0, 1, 2], 1), ([1, 2, 3], 1), ([2, 3, 4], 1), ([3, 4, 5], 1), ([4, 5, 6], 1), ([5, 6, 7], 1), ([6, 7, 8], 1), ([7, 8, 9], 1), ([0], 2), ([0, 1], 2), ([0, 1, 2], 2), ([1, 2, 3], 2), ([2, 3, 4], 2), ([3, 4, 5], 2), ([4, 5, 6], 2), ([5, 6, 7], 2), ([6, 7, 8], 2), ([7, 8, 9], 2), ([0], 3), ([0, 1], 3), ([0, 1, 2], 3), ([1, 2, 3], 3), ([2, 3, 4], 3), ([3, 4, 5], 3), ([4, 5, 6], 3), ([5, 6, 7], 3), ([6, 7, 8], 3), ([7, 8, 9], 3), ([0], 4), ([0, 1], 4), ([0, 1, 2], 4), ([1, 2, 3], 4), ([2, 3, 4], 4), ([3, 4, 5], 4), ([4, 5, 6], 4), ([5, 6, 7], 4), ([6, 7, 8], 4), ([7, 8, 9], 4), ([0], 5), ([0, 1], 5), ([0, 1, 2], 5), ([1, 2, 3], 5), ([2, 3, 4], 5), ([3, 4, 5], 5), ([4, 5, 6], 5), ([5, 6, 7], 5), ([6, 7, 8], 5), ([7, 8, 9], 5), ([0], 6), ([0, 1], 6), ([0, 1, 2], 6), ([1, 2, 3], 6), ([2, 3, 4], 6), ([3, 4, 5], 6), ([4, 5, 6], 6), ([5, 6, 7], 6), ([6, 7, 8], 6), ([7, 8, 9], 6), ([0], 7), ([0, 1], 7), ([0, 1, 2], 7), ([1, 2, 3], 7), ([2, 3, 4], 7), ([3, 4, 5], 7), ([4, 5, 6], 7), ([5, 6, 7], 7), ([6, 7, 8], 7), ([7, 8, 9], 7), ([0], 8), ([0, 1], 8), ([0, 1, 2], 8), ([1, 2, 3], 8), ([2, 3, 4], 8), ([3, 4, 5], 8), ([4, 5, 6], 8), ([5, 6, 7], 8), ([6, 7, 8], 8), ([7, 8, 9], 8), ([0], 9), ([0, 1], 9), ([0, 1, 2], 9), ([1, 2, 3], 9), ([2, 3, 4], 9), ([3, 4, 5], 9), ([4, 5, 6], 9), ([5, 6, 7], 9), ([6, 7, 8], 9), ([7, 8, 9], 9)]    

This is done by list comprehension(which makes looping elements in a list via one line code possible). The logic behind this one-line code is the following:

(1) for x in range(10) and for y in range(10) are employed for two independent loops inside a list

(2) (a list, y) is the general term of the loop, which is why it is placed before two for's in (1)

(3) the length of the list in (2) cannot exceed 3, and the list depends on x, so

[z for z in range(x-2,x+1)] 

is used

(4) because z starts from zero but range(x-2,x+1) starts from -2 which isn't what we want, so a conditional statement if z >= 0 is placed at the end of the list in (2)

[z for z in range(x-2,x+1) if z >= 0] 

Replace Div Content onclick

Try This:

I think that you want something like this.


<div id="1">
    My Content 1

<div id="2" style="display:none;">
    My Dynamic Content
<button id="btnClick">Click me!</button>


}else if($('#2').css('display')!='none'){

JsFiddle: <--- see this I hope You want something like this.

Center the nav in Twitter Bootstrap

For Bootstrap v4 check this:

only add class to ul.pagination:

  <ul class="pagination justify-content-center">
    <li class="page-item disabled">
      <a class="page-link" href="#" tabindex="-1">Previous</a>
    <li class="page-item"><a class="page-link" href="#">1</a></li>
    <li class="page-item"><a class="page-link" href="#">2</a></li>
    <li class="page-item"><a class="page-link" href="#">3</a></li>
    <li class="page-item">
      <a class="page-link" href="#">Next</a>

Removing a Fragment from the back stack

you show fragment in a container (with id= fragmentcontainer) so you remove fragment with:

 Fragment fragment = getSupportFragmentManager().findFragmentById(;

When is TCP option SO_LINGER (0) required?

In servers, you may like to send RST instead of FIN when disconnecting misbehaving clients. That skips FIN-WAIT followed by TIME-WAIT socket states in the server, which prevents from depleting server resources, and, hence, protects from this kind of denial-of-service attack.

Histogram Matplotlib

If you're willing to use pandas:


Git - Undo pushed commits

The reset hard worked for me: Thanks @Mo D Genensis and @vibs2006

git reset --hard 'your last working commit hash'

git clean -f -d

git push -f

jQuery Multiple ID selectors

it should. Typically that's how you do multiple selectors. Otherwise it may not like you trying to assign the return values of three uploads to the same var.

I would suggest using .each or maybe push the returns to an array rather than assigning them to that value.

Removing html5 required attribute with jQuery

Even though the ID selector is the simplest, you can also use the name selector as below:


For more see:

Access to the requested object is only available from the local network phpmyadmin

If you see below error message, when try into phpyAdmin:

New XAMPP security concept:
Access to the requested directory is only available from the local network.
This setting can be configured in the file "httpd-xampp.conf".

You can do next (for XAMPP, deployed on the UNIX-system): You can try change configuration for <Directory "/opt/lampp/phpmyadmin">

# vi /opt/lampp/etc/extra/httpd-xampp.conf

and change security settings to

#LoadModule perl_module        modules/

<Directory "/opt/lampp/phpmyadmin">
    AllowOverride AuthConfig Limit
    Order allow,deny
    Allow from all
    Require all granted
    ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var

First - comment pl module, second - change config for node Directory. After it, you should restart httpd daemon

# /opt/lampp/xampp restart

Now you can access http://[server_ip]/phpmyadmin/

How to check if directory exists in %PATH%?

Another way to check if something is in the path is to execute some innocent executable that is not going to fail if it's there, and check the result. As an example, next code snippet checks if maven is in the path:

mvn --help > NUL 2> NUL 
if errorlevel 1 goto mvnNotInPath

So I try to run mvn --help, ignore the output (don't actually want to see the help if maven is there)( > NUL), and also don't display the error message if maven was not found (2> NUL).

How do you execute SQL from within a bash script?

Maybe you can pipe SQL query to sqlplus. It works for mysql:

echo "SELECT * FROM table" | mysql --user=username database

How to get base url in CodeIgniter 2.*

I know this is very late, but is useful for newbies. We can atuload url helper and it will be available throughout the application. For this in application\config\autoload.php modify as follows -

$autoload['helper'] = array('url'); 

How to localise a string inside the iOS info.plist file?

For anyone experiencing the problem of the info.plist not being included when trying to add localizations, like in Xcode 9.

You need make the info.plist localiazble by going into it and clicking on the localize button in the file inspector, as shown below.

The info.plist will then be included in the file resources for when you go to add new Localizations.

enter image description here

What is the difference between CSS and SCSS?

Variable definitions right:

$      => SCSS, SASS
--     => CSS
@      => LESS

All answers is good but question a little different than answers

"about Sass. How is SCSS different from CSS" : scss is well formed CSS3 syntax. uses sass preprocessor to create that.

and if I use SCSS instead of CSS will it work the same? yes. if your ide supports sass preprocessor. than it will work same.

Sass has two syntaxes. The most commonly used syntax is known as “SCSS” (for “Sassy CSS”), and is a superset of CSS3’s syntax. This means that every valid CSS3 stylesheet is valid SCSS as well. SCSS files use the extension .scss.

The second, older syntax is known as the indented syntax (or just “.sass”). Inspired by Haml’s terseness, it’s intended for people who prefer conciseness over similarity to CSS. Instead of brackets and semicolons, it uses the indentation of lines to specify blocks. Files in the indented syntax use the extension .sass.

  • Furher Information About:

What Is A CSS Preprocessor?

CSS in itself is devoid of complex logic and functionality which is required to write reusable and organized code. As a result, a developer is bound by limitations and would face extreme difficulty in code maintenance and scalability, especially when working on large projects involving extensive code and multiple CSS stylesheets. This is where CSS Preprocessors come to the rescue.

A CSS Preprocessor is a tool used to extend the basic functionality of default vanilla CSS through its own scripting language. It helps us to use complex logical syntax like – variables, functions, mixins, code nesting, and inheritance to name a few, supercharging your vanilla CSS. By using CSS Preprocessors, you can seamlessly automate menial tasks, build reusable code snippets, avoid code repetition and bloating and write nested code blocks that are well organized and easy to read. However, browsers can only understand native vanilla CSS code and will be unable to interpret the CSS Preprocessor syntax. Therefore, the complex and advanced Preprocessor syntax needs to be first compiled into native CSS syntax which can then be interpreted by the browsers to avoid cross browser compatibility issues. While different Preprocessors have their own unique syntaxes, eventually all of them are compiled to the same native CSS code.

Moving forward in the article, we will take a look at the 3 most popular CSS Preprocessors currently being used by developers around the world i.e Sass, LESS, and Stylus. Before you decide the winner between Sass vs LESS vs Stylus, let us get to know them in detail first.

Sass – Syntactically Awesome Style Sheets

Sass is the acronym for “Syntactically Awesome Style Sheets”. Sass is not only the most popular CSS Preprocessor in the world but also one of the oldest, launched in 2006 by Hampton Catlin and later developed by Natalie Weizenbaum. Although Sass is written in Ruby language, a Precompiler LibSass allows Sass to be parsed in other languages and decouple it from Ruby. Sass has a massive active community and extensive learning resources available on the net for beginners. Thanks to its maturity, stability and powerful logical prowess, Sass has established itself to the forefront of CSS Preprocessor ahead of its rival peers.

Sass can be written in 2 syntaxes either using Sass or SCSS. What is the difference between the two? Let’s find out.

Syntax Declaration: Sass vs SCSS

  • SCSS stands for Sassy CSS. Unlike Sass, SCSS is not based on indentation.
  • .sass extension is used as original syntax for Sass, while SCSS offers a newer syntax with .scss extension.
  • Unlike Sass, SCSS has curly braces and semicolons, just like CSS.
  • Contrary to SCSS, Sass is difficult to read as it is quite deviant from CSS. Which is why SCSS it the more recommended Sass syntax as it is easier to read and closely resembles Native CSS while at the same time enjoying with power of Sass.

Consider the example below with Sass vs SCSS syntax along with Compiled CSS code.

    $font-color: #fff
    $bg-color: #00f

      color: $font-color
      background: $bg-color

    $font-color: #fff;
    $bg-color: #00f;

      color: $font-color;
      background: $bg-color;

In both cases, be it Sass or SCSS, the compiled CSS code will be the same –

#box {
      color: #fff;
      background: #00f;

Usage of Sass

Arguably the most Popular front end framework Bootstrap is written in Sass. Up until version 3, Bootstrap was written in LESS but bootstrap 4 adopted Sass and boosted its popularity. A few of the big companies using Sass are – Zapier, Uber, Airbnb and Kickstarter.

LESS – Leaner Style Sheets

LESS is an acronym for “Leaner Stylesheets”. It was released in 2009 by Alexis Sellier, 3 years after the initial launch of Sass in 2006. While Sass is written in Ruby, LESS is written JavaScript. In fact, LESS is a JavaScript library that extends the functionality of native vanilla CSS with mixins, variables, nesting and rule set loop. Sass vs LESS has been a heated debate. It is no surprise that LESS is the strongest competitor to Sass and has the second-largest user base. However, When bootstrap dumped LESS in favor of Sass with the launch of Bootstrap 4, LESS has waned in popularity. One of the few disadvantages of LESS over Sass is that it does not support functions. Unlike Sass, LESS uses @ to declare variables which might cause confusion with @media and @keyframes. However, One key advantage of LESS over Sass and Stylus or any other preprocessors, is the ease of adding it in your project. You can do that either by using NPM or by incorporating Less.js file. Syntax Declaration: LESS Uses .less extension. Syntax of LESS is quite similar to SCSS with the exception that for declaring variables, instead of $ sign, LESS uses @.

@font-color: #fff;
    @bg-color: #00f

      color: @font-color;
      background: @bg-color;

    #box {
        color: #fff;
        background: #00f;

Usage Of LESS The popular Bootstrap framework until the launch of version 4 was written in LESS. However, another popular framework called SEMANTIC UI is still written in LESS. Among the big companies using Sass are – Indiegogo, Patreon, and WeChat


The stylus was launched in 2010 by former Node JS developer TJ Holowaychuk, nearly 4 years after the release of Sass and 1 year after the release of LESS. The stylus is written Node JS and fits perfectly with JS stack. The stylus was heavily influenced by the logical prowess of the Sass and simplicity of LESS. Even though Stylus is still popular with Node JS developers, it hasn’t managed to carve out a sizeable share for itself. One advantage of Stylus over Sass or LESS, is that it is armed with extremely powerful built-in functions and is capable of handling heavy computing.

Syntax Declaration: Stylus Uses .styl extension. Stylus offers a great deal of flexibility in writing syntax, supports native CSS as well as allows omission of brackets colons and semicolons. Also, note that Stylus does not use @ or $ symbols for defining variables. Instead, Stylus uses the assignment operators to indicate a variable declaration.


font-color = #fff;
bg-color = #00f;

#box {
    color: font-color;
    background: bg-color;



font-color = #fff;
bg-color = #00f;

    color: font-color;
    background: bg-color;



font-color = #fff
bg-color = #00f

    color font-color
    background bg-color

using javascript to detect whether the url exists before display in iframe

Due to my low reputation I couldn't comment on Derek ????'s answer. I've tried that code as it is and it didn't work well. There are three issues on Derek ????'s code.

  1. The first is that the time to async send the request and change its property 'status' is slower than to execute the next expression - if(request.status === "404"). So the request.status will eventually, due to internet band, remain on status 0 (zero), and it won't achieve the code right below if. To fix that is easy: change 'true' to 'false' on method open of the ajax request. This will cause a brief (or not so) block on your code (due to synchronous call), but will change the status of the request before reaching the test on if.

  2. The second is that the status is an integer. Using '===' javascript comparison operator you're trying to compare if the left side object is identical to one on the right side. To make this work there are two ways:

    • Remove the quotes that surrounds 404, making it an integer;
    • Use the javascript's operator '==' so you will be testing if the two objects are similar.
  3. The third is that the object XMLHttpRequest only works on newer browsers (Firefox, Chrome and IE7+). If you want that snippet to work on all browsers you have to do in the way W3Schools suggests: w3schools ajax

The code that really worked for me was:

var request;
    request = new XMLHttpRequest();
    request = new ActiveXObject("Microsoft.XMLHTTP");'GET', '', false);
request.send(); // there will be a 'pause' here until the response to come.
// the object request will be actually modified
if (request.status === 404) {
    alert("The page you are trying to reach is not available.");

Repeat each row of data.frame the number of times specified in a column

I know this is not the case but if you need to keep the original freq column, you can use another tidyverse approach together with rep:


df <- data.frame(var1 = c('a', 'b', 'c'), var2 = c('d', 'e', 'f'), freq = 1:3)

df %>% 
  map_df(., rep, .$freq)
#> # A tibble: 6 x 3
#>   var1  var2   freq
#>   <fct> <fct> <int>
#> 1 a     d         1
#> 2 b     e         2
#> 3 b     e         2
#> 4 c     f         3
#> 5 c     f         3
#> 6 c     f         3

Created on 2019-12-21 by the reprex package (v0.3.0)

Declaring a boolean in JavaScript using just var

No it is not safe. You could later do var IsLoggedIn = "Foo"; and JavaScript will not throw an error.

It is possible to do

var IsLoggedIn = new Boolean(false);
var IsLoggedIn = new Boolean(true);

You can also pass the non boolean variable into the new Boolean() and it will make IsLoggedIn boolean.

var IsLoggedIn = new Boolean(0); // false
var IsLoggedIn = new Boolean(NaN); // false
var IsLoggedIn = new Boolean("Foo"); // true
var IsLoggedIn = new Boolean(1); // true

Can I catch multiple Java exceptions in the same catch clause?

It is very simple:

try { 
  // Your code here.
} catch (IllegalArgumentException | SecurityException | IllegalAccessException |
            NoSuchFieldException e) { 
  // Handle exception here.

Could not locate Gemfile

Here is something you could try.

Add this to any config files you use to run your app.

ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
require 'bundler/setup' # Set up gems listed in the Gemfile.

Rails and other Rack based apps use this scheme. It happens sometimes that you are trying to run things which are some directories deeper than your root where your Gemfile normally is located. Of course you solved this problem for now but occasionally we all get into trouble with this finding the Gemfile. I sometimes like when you can have all you gems in the .bundle directory also. It never hurts to keep this site address under your pillow.

How to find foreign key dependencies in SQL Server?

SELECT AS FK_NAME, AS [schema_name], AS [table], AS [column], AS [referenced_table], AS [referenced_column]
FROM sys.foreign_key_columns fkc
INNER JOIN sys.objects obj
    ON obj.object_id = fkc.constraint_object_id
INNER JOIN sys.tables tab1
    ON tab1.object_id = fkc.parent_object_id
INNER JOIN sys.schemas sch
    ON tab1.schema_id = sch.schema_id
INNER JOIN sys.columns col1
    ON col1.column_id = parent_column_id AND col1.object_id = tab1.object_id
INNER JOIN sys.tables tab2
    ON tab2.object_id = fkc.referenced_object_id
INNER JOIN sys.columns col2
    ON col2.column_id = referenced_column_id AND col2.object_id = tab2.object_id

It will give you:

The FK itself Schema that the FK belongs to

  • The "referencing table" or the table that has the FK
  • The "referencing column" or the column inside referencing table that points to the FK
  • The "referenced table" or the table that has the key column that your FK is pointing to
  • The "referenced column" or the column that is the key that your FK is pointing to

Assigning multiple styles on an HTML element

The syntax you used is problematic. In html, an attribute (ex: style) has a value delimited by double quotes. In that case, the value of the style attribute is a css list of selectors. Try this:

<h2 style="text-align:center; font-family:tahoma">TITLE</h2>

Center align "span" text inside a div

If you know the width of the span you could just stuff in a left margin.

Try this:

.center { text-align: center} span { display: table; }

Add the "center: class to your .

If you want some spans centered, but not others, replace the " span" in your style sheet to a class (e.g "center-span") and add that class to the span.

plain count up timer in javascript

Here is an React (Native) version:

import React, { Component } from 'react';
import {
} from 'react-native';

export default class CountUp extends Component  {

    state = {
        seconds: null,

    get formatedTime() {
        const { seconds } = this.state;

        return [
            pad(parseInt(seconds / 60)),
            pad(seconds % 60),

    componentWillMount() {
        this.setState({ seconds: 0 });

    componentDidMount() {
        this.timer = setInterval(
            () => this.setState({
                seconds: ++this.state.seconds

    componentWillUnmount() {

    render() {
        return (

function pad(num) {
    return num.toString().length > 1 ? num : `0${num}`;

Execute multiple command lines with the same process using .NET

You can redirect standard input and use a StreamWriter to write to it:

        Process p = new Process();
        ProcessStartInfo info = new ProcessStartInfo();
        info.FileName = "cmd.exe";
        info.RedirectStandardInput = true;
        info.UseShellExecute = false;

        p.StartInfo = info;

        using (StreamWriter sw = p.StandardInput)
            if (sw.BaseStream.CanWrite)
                sw.WriteLine("mysql -u root -p");
                sw.WriteLine("use mydb;");

Change language for bootstrap DateTimePicker

This is for your reference only:

The case is as follows:

 <div class="input" id="event_period">
   <input class="date" required="required" type="text">

 $.fn.datepicker.dates['zh-CN'] = {

    inputs: $(''),
    todayBtn: "linked",
    clearBtn: true,
    format: "yyyy?mm?",
    titleFormat: "yyyy?mm?",
    language: 'zh-CN',
    weekStart:1 // Available or not

Import Certificate to Trusted Root but not to Personal [Command Line]

The below 'd help you to add the cert to the Root Store-

certutil -enterprise -f -v -AddStore "Root" <Cert File path>

This worked for me perfectly.

How to replace blank (null ) values with 0 for all records?

UPDATE table SET column=0 WHERE column IS NULL

difference between System.out.println() and System.err.println()

System.out is "standard output" (stdout) and System.err is "error output" (stderr). Along with (stdin), these are the three standard I/O streams in the Unix model. Most modern programming environments (C, Perl, etc.) support this model.

The standard output stream is used to print output from "normal operations" of the program, while the error stream is for "error messages". These need to be separate -- though in most cases they appear on the same console.

Suppose you have a simple program where you enter a phone number and it prints out the person who has that number. If you enter an invalid number, the program should inform you of that error, but it shouldn't do that as the answer: If you enter "999-ABC-4567" and the program prints an error message "Not a valid number", that doesn't mean there is a person named "Not a valid number" whose number is 999-ABC-4567. So it prints out nothing to the standard output, and the message "Not a valid number" is printed to the error output.

You can set up the execution environment to distinguish between the two streams, for example, make the standard output print to the screen and error output print to a file.

Android: how do I check if activity is running?

You can use a static variable within the activity.

class MyActivity extends Activity {
     static boolean active = false;

      public void onStart() {
         active = true;

      public void onStop() {
         active = false;

The only gotcha is that if you use it in two activities that link to each other then onStop on the first is sometimes called after onStart in second. So both might be true briefly.

Depending on what you are trying to do (update the current activity from a service?). You could just register a static listener in the service in your activity onStart method then the correct listener will be available when your service wants to update the UI.

Change collations of all columns of all tables in SQL Server

As I did not find a proper way I wrote a script to do it and I'm sharing it here for those who need it. The script runs through all user tables and collects the columns. If the column type is any char type then it tries to convert it to the given collation.

Columns has to be index and constraint free for this to work.

If someone still has a better solution to this please post it!

DECLARE @collate nvarchar(100);
DECLARE @table nvarchar(255);
DECLARE @column_name nvarchar(255);
DECLARE @column_id int;
DECLARE @data_type nvarchar(255);
DECLARE @max_length int;
DECLARE @row_id int;
DECLARE @sql nvarchar(max);
DECLARE @sql_column nvarchar(max);

SET @collate = 'Latin1_General_CI_AS';

DECLARE local_table_cursor CURSOR FOR

SELECT [name]
FROM sysobjects

OPEN local_table_cursor
FETCH NEXT FROM local_table_cursor
INTO @table


    DECLARE local_change_cursor CURSOR FOR

    SELECT ROW_NUMBER() OVER (ORDER BY c.column_id) AS row_id
        , column_name
        , t.Name data_type
        , c.max_length
        , c.column_id
    FROM sys.columns c
    JOIN sys.types t ON c.system_type_id = t.system_type_id
    LEFT OUTER JOIN sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
    LEFT OUTER JOIN sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
    WHERE c.object_id = OBJECT_ID(@table)
    ORDER BY c.column_id

    OPEN local_change_cursor
    FETCH NEXT FROM local_change_cursor
    INTO @row_id, @column_name, @data_type, @max_length, @column_id


        IF (@max_length = -1) OR (@max_length > 4000) SET @max_length = 4000;

        IF (@data_type LIKE '%char%')
        BEGIN TRY
            SET @sql = 'ALTER TABLE ' + @table + ' ALTER COLUMN ' + @column_name + ' ' + @data_type + '(' + CAST(@max_length AS nvarchar(100)) + ') COLLATE ' + @collate
            PRINT @sql
            EXEC sp_executesql @sql
        END TRY
          PRINT 'ERROR: Some index or constraint rely on the column' + @column_name + '. No conversion possible.'
          PRINT @sql
        END CATCH

        FETCH NEXT FROM local_change_cursor
        INTO @row_id, @column_name, @data_type, @max_length, @column_id


    CLOSE local_change_cursor
    DEALLOCATE local_change_cursor

    FETCH NEXT FROM local_table_cursor
    INTO @table


CLOSE local_table_cursor
DEALLOCATE local_table_cursor


How to use Angular4 to set focus by element id

I also face same issue after some search I found a good solution as @GreyBeardedGeek mentioned that setTimeout is the key of this solution.He is totally correct. In your method you just need to add setTimeout and your problem will be solved.

setTimeout(() => this.inputEl.nativeElement.focus(), 0);

The target ... overrides the `OTHER_LDFLAGS` build setting defined in `Pods/Pods.xcconfig

I added $(inherited) but my project was still not compiling. For me problem was flag "Build for active Architecture only", I had to set it to YES.

How can I run a function from a script in command line?

Briefly, no.

You can import all of the functions in the script into your environment with source (help source for details), which will then allow you to call them. This also has the effect of executing the script, so take care.

There is no way to call a function from a shell script as if it were a shared library.

Number of days between past date and current date in Google spreadsheet

If you are using the two formulas at the same time, it will not work... Here is a simple spreadsheet with it working: If you are still getting problems I would need to know what type of erroneous result you are getting.

Today() returns a numeric integer value: Returns the current computer system date. The value is updated when your document recalculates. TODAY is a function without arguments.

How to list the files inside a JAR file?

A jar file is just a zip file with a structured manifest. You can open the jar file with the usual java zip tools and scan the file contents that way, inflate streams, etc. Then use that in a getResourceAsStream call, and it should be all hunky dory.

EDIT / after clarification

It took me a minute to remember all the bits and pieces and I'm sure there are cleaner ways to do it, but I wanted to see that I wasn't crazy. In my project image.jpg is a file in some part of the main jar file. I get the class loader of the main class (SomeClass is the entry point) and use it to discover the image.jpg resource. Then some stream magic to get it into this ImageInputStream thing and everything is fine.

InputStream inputStream = SomeClass.class.getClassLoader().getResourceAsStream("image.jpg");
JPEGImageReaderSpi imageReaderSpi = new JPEGImageReaderSpi();
ImageReader ir = imageReaderSpi.createReaderInstance();
ImageInputStream iis = new MemoryCacheImageInputStream(inputStream);
....; //will hand us a buffered image

Base table or view not found: 1146 Table Laravel 5

I'm guessing Laravel can't determine the plural form of the word you used for your table name.

Just specify your table in the model as such:

class Cotizacion extends Model{
    public $table = "cotizacion";

JPanel vs JFrame in Java

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

You need a Swing tutorial:

Pass array to mvc Action via AJAX

Set the traditional property to true before making the get call. i.e.:

jQuery.ajaxSettings.traditional = true

$.get('/controller/MyAction', { vals: arrayOfValues }, function (data) {... 

What is a reasonable code coverage % for unit tests (and why)?

If this were a perfect world, 100% of code would be covered by unit tests. However, since this is NOT a perfect world, it's a matter of what you have time for. As a result, I recommend focusing less on a specific percentage, and focusing more on the critical areas. If your code is well-written (or at least a reasonable facsimile thereof) there should be several key points where APIs are exposed to other code.

Focus your testing efforts on these APIs. Make sure that the APIs are 1) well documented and 2) have test cases written that match the documentation. If the expected results don't match up with the docs, then you have a bug in either your code, documentation, or test cases. All of which are good to vet out.

Good luck!

How to export data to an excel file using PHPExcel

If you've copied this directly, then:

->setCellValue('B2', Ackermann') 

should be

->setCellValue('B2', 'Ackermann') 

In answer to your question:

Get the data that you want from limesurvey, and use setCellValue() to store those data values in the cells where you want to store it.

The Quadratic.php example file in /Tests might help as a starting point: it takes data from an input form and sets it to cells in an Excel workbook.


An extremely simplistic example:

// Create your database query
$query = "SELECT * FROM myDataTable";  

// Execute the database query
$result = mysql_query($query) or die(mysql_error());

// Instantiate a new PHPExcel object
$objPHPExcel = new PHPExcel(); 
// Set the active Excel worksheet to sheet 0
// Initialise the Excel row number
$rowCount = 1; 
// Iterate through each result from the SQL query in turn
// We fetch each database result row into $row in turn
while($row = mysql_fetch_array($result)){ 
    // Set cell An to the "name" column from the database (assuming you have a column called name)
    //    where n is the Excel row number (ie cell A1 in the first row)
    $objPHPExcel->getActiveSheet()->SetCellValue('A'.$rowCount, $row['name']); 
    // Set cell Bn to the "age" column from the database (assuming you have a column called age)
    //    where n is the Excel row number (ie cell A1 in the first row)
    $objPHPExcel->getActiveSheet()->SetCellValue('B'.$rowCount, $row['age']); 
    // Increment the Excel row counter

// Instantiate a Writer to create an OfficeOpenXML Excel .xlsx file
$objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel); 
// Write the Excel file to filename some_excel_file.xlsx in the current directory


Using your existing code as the basis

// Instantiate a new PHPExcel object 
$objPHPExcel = new PHPExcel();  
// Set the active Excel worksheet to sheet 0 
// Initialise the Excel row number 
$rowCount = 1;  

//start of printing column names as names of MySQL fields  
$column = 'A';
for ($i = 1; $i < mysql_num_fields($result); $i++)  
    $objPHPExcel->getActiveSheet()->setCellValue($column.$rowCount, mysql_field_name($result,$i));
//end of adding column names  

//start while loop to get data  
$rowCount = 2;  
while($row = mysql_fetch_row($result))  
    $column = 'A';
    for($j=1; $j<mysql_num_fields($result);$j++)  
            $value = NULL;  
        elseif ($row[$j] != "")  
            $value = strip_tags($row[$j]);  
            $value = "";  

        $objPHPExcel->getActiveSheet()->setCellValue($column.$rowCount, $value);

// Redirect output to a client’s web browser (Excel5) 
header('Content-Type: application/'); 
header('Content-Disposition: attachment;filename="Limesurvey_Results.xls"'); 
header('Cache-Control: max-age=0'); 
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5'); 

Linq order by, group by and order by each group?

The way to do it without projection:

StudentsGrades.OrderBy(student => student.Name).
ThenBy(student => student.Grade);

Counting number of lines, words, and characters in a text file

class wordcount
    public static int words=0;
    public static int lines=0;
    public static int chars=0;
    public static void wc(InputStreamReader isr)throws IOException
        int c=0;
        boolean lastwhite=true;
            if(c=='\t' || c==' ' || c=='\n')
    public static void main(String[] args)
        FileReader fr;
                wc(new InputStreamReader(;
                for(int i=0;i<args.length;i++)
                    fr=new FileReader(args[i]);

        catch(IOException ie)
        System.out.println(lines+" "+words+" "+chars);

Access Control Request Headers, is added to header in AJAX request with jQuery

What you saw in Firefox was not the actual request; note that the HTTP method is OPTIONS, not POST. It was actually the 'pre-flight' request that the browser makes to determine whether a cross-domain AJAX request should be allowed:

The Access-Control-Request-Headers header in the pre-flight request includes the list of headers in the actual request. The server is then expected to report back whether these headers are supported in this context or not, before the browser submits the actual request.

SLF4J: Class path contains multiple SLF4J bindings

I had the same problem. In my pom.xml i had both



When i deleted the spring-boot-starter-web dependency, problem was solved.

Efficient way to determine number of digits in an integer

The simplest way is to do:

unsigned GetNumberOfDigits (unsigned i)
    return i > 0 ? (int) log10 ((double) i) + 1 : 1;

log10 is defined in <cmath> or <math.h>. You'd need to profile this to see if it's faster than any of the others posted here. I'm not sure how robust this is with regards to float point precision. Also, the argument is unsigned as negative values and log don't really mix.

How to convert std::chrono::time_point to calendar datetime string with fractional seconds?

If you are to format a system_clock::time_point in the format of numpy datetime64, you could use:

std::string format_time_point(system_clock::time_point point)
    static_assert(system_clock::time_point::period::den == 1000000000 && system_clock::time_point::period::num == 1);
    std::string out(29, '0');
    char* buf = &out[0];
    std::time_t now_c = system_clock::to_time_t(point);
    std::strftime(buf, 21, "%Y-%m-%dT%H:%M:%S.", std::localtime(&now_c));
    sprintf(buf+20, "%09ld", point.time_since_epoch().count() % 1000000000);
    return out;

sample output: 2019-11-19T17:59:58.425802666

Group by & count function in sqlalchemy

You can also count on multiple groups and their intersection:

self.session.query(func.count(Table.column1),Table.column1, Table.column2).group_by(Table.column1, Table.column2).all()

The query above will return counts for all possible combinations of values from both columns.

Eclipse error: 'Failed to create the Java Virtual Machine'

This may work:

Open eclipse.ini file and paste below lines at the end of the lines.


How to import popper.js?

IN bootstrap 4 you need to add popper js for tooltip, I also don`t understand why bootstrap 4 includes external popper.js, It means bootstrap makes more complicated instead of easy when upgrading to the latest versions.

You can import popper js before bootstrap on angular or a simple html, Angular import would be like this

npm install popper.js --save

then go to .angular-cli.json and change the order like below.

 "scripts": [

you can also use CDN direct call popper js into your any project.

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare();

Here's what I've been doing:

  public void displayError(final String errorText) {
    Runnable doDisplayError = new Runnable() {
        public void run() {
            Toast.makeText(getApplicationContext(), errorText, Toast.LENGTH_LONG).show();

That should allow the method to be called from either thread.

Where messageHandler is declared in the activity as ..

Handler messageHandler = new Handler();

DB2 Timestamp select statement

@bhamby is correct. By leaving the microseconds off of your timestamp value, your query would only match on a usagetime of 2012-09-03 08:03:06.000000

If you don't have the complete timestamp value captured from a previous query, you can specify a ranged predicate that will match on any microsecond value for that time:

...WHERE id = 1 AND usagetime BETWEEN '2012-09-03 08:03:06' AND '2012-09-03 08:03:07'


...WHERE id = 1 AND usagetime >= '2012-09-03 08:03:06' 
   AND usagetime < '2012-09-03 08:03:07'

jQuery selectors on custom data attributes using HTML5

Pure/vanilla JS solution (working example here)

// All elements with data-company="Microsoft" below "Companies"
let a = document.querySelectorAll("[data-group='Companies'] [data-company='Microsoft']"); 

// All elements with data-company!="Microsoft" below "Companies"
let b = document.querySelectorAll("[data-group='Companies'] :not([data-company='Microsoft'])"); 

In querySelectorAll you must use valid CSS selector (currently Level3)

SPEED TEST (2018.06.29) for jQuery and Pure JS: test was performed on MacOs High Sierra 10.13.3 on Chrome 67.0.3396.99 (64-bit), Safari 11.0.3 (13604.5.6), Firefox 59.0.2 (64-bit). Below screenshot shows results for fastest browser (Safari):

enter image description here

PureJS was faster than jQuery about 12% on Chrome, 21% on Firefox and 25% on Safari. Interestingly speed for Chrome was 18.9M operation per second, Firefox 26M, Safari 160.9M (!).

So winner is PureJS and fastest browser is Safari (more than 8x faster than Chrome!)

Here you can perform test on your machine:

How to add hours to current date in SQL Server?

declare @hours int = 5;

select dateadd(hour,@hours,getdate())

How to force input to only allow Alpha Letters?

Rather than relying on key codes, which can be quite cumbersome, you can instead use regular expressions. By changing the pattern we can easily restrict the input to fit our needs. Note that this works with the keypress event and will allow the use of backspace (as in the accepted answer). It will not prevent users from pasting 'illegal' chars.

function testInput(event) {_x000D_
   var value = String.fromCharCode(event.which);_x000D_
   var pattern = new RegExp(/[a-zåäö ]/i);_x000D_
   return pattern.test(value);_x000D_
$('#my-field').bind('keypress', testInput);
<script src=""></script>_x000D_
   Test input:_x000D_
   <input id="my-field" type="text">_x000D_

Android Studio : Failure [INSTALL_FAILED_OLDER_SDK]

Try changing you sdk min version

    android:targetSdkVersion="19" />

PHP Multiple Checkbox Array

<form method='post' id='userform' action='thisform.php'> <tr>
    <td>Trouble Type</td>
    <input type='checkbox' name='checkboxvar[]' value='Option One'>1<br>
    <input type='checkbox' name='checkboxvar[]' value='Option Two'>2<br>
    <input type='checkbox' name='checkboxvar[]' value='Option Three'>3
    </td> </tr> </table> <input type='submit' class='buttons'> </form>

if (isset($_POST['checkboxvar'])) 

You pass the form name as an array and then you can access all checked boxes using the var itself which would then be an array.

To echo checked options into your email you would then do this:

echo implode(',', $_POST['checkboxvar']); // change the comma to whatever separator you want

Please keep in mind you should always sanitize your input as needed.

For the record, official docs on this exist:

Remove all classes that begin with a certain string

Using 2nd signature of $.fn.removeClass :

// Considering:
var $el = $('<div class="  foo-1 a b foo-2 c foo"/>');

function makeRemoveClassHandler(regex) {
  return function (index, classes) {
    return classes.split(/\s+/).filter(function (el) {return regex.test(el);}).join(' ');

//> [<div class=?"a b c foo">?</div>?]

Android button font size

Another approach:

declaring an int first with the default fontsize

int txtSize = 16;

           button.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {

open existing java project in eclipse

The typical pattern is to check out the root project folder (=the one containing a file called ".project") from SVN using eclipse's svn integration (SVN repository exploring perspective). The project is then recognized automatically.

How do I remove version tracking from a project cloned from git?

rm -rf .git should suffice. That will blow away all Git-related information.

How do you get the current text contents of a QComboBox?

You can convert the QString type to python string by just using the str function. Assuming you are not using any Unicode characters you can get a python string as below:

text = str(combobox1.currentText())

If you are using any unicode characters, you can do:

text = unicode(combobox1.currentText())

Android Activity as a dialog

Use this code so that the dialog activity won't be closed when the user touches outside the dialog box:


requires API level 11

How to normalize a histogram in MATLAB?

hist can not only plot an histogram but also return you the count of elements in each bin, so you can get that count, normalize it by dividing each bin by the total and plotting the result using bar. Example:

Y = rand(10,1);
C = hist(Y);
C = C ./ sum(C);

or if you want a one-liner:

bar(hist(Y) ./ sum(hist(Y)))


Edit: This solution answers the question How to have the sum of all bins equal to 1. This approximation is valid only if your bin size is small relative to the variance of your data. The sum used here correspond to a simple quadrature formula, more complex ones can be used like trapz as proposed by R. M.

Generate getters and setters in NetBeans

Position the cursor inside the class, then press ALT + Ins and select Getters and Setters from the contextual menu.

Filtering DataSet

No mention of Merge?

DataSet newdataset = new DataSet();

newdataset.Merge( olddataset.Tables[0].Select( filterstring, sortstring ));

Javascript parse float is ignoring the decimals after my comma

parseFloat parses according to the JavaScript definition of a decimal literal, not your locale's definition. (E.g., parseFloat is not locale-aware.) Decimal literals in JavaScript use . for the decimal point.

How to convert date format to milliseconds?

beginupd.getTime() will give you time in milliseconds since January 1, 1970, 00:00:00 GMT till the time you have specified in Date object

Why SpringMVC Request method 'GET' not supported?

method = POST will work if you 'post' a form to the url /test.

if you type a url in address bar of a browser and hit enter, it's always a GET request, so you had to specify POST request.

Google for HTTP GET and HTTP POST (there are several others like PUT DELETE). They all have their own meaning.

How to call two methods on button's onclick method in HTML or JavaScript?

  1. Try this:

    <input type="button" onclick="function1();function2();" value="Call2Functions" />
  2. Or, call second function at the end of first function:

       function func1(){
         //--- some logic
       function func2(){
        //--- some logic

    ...and call func1() onclick of button:

    <input type="button" onclick="func1();" value="Call2Functions" />

raw_input function in Python

raw_input() was renamed to input() in Python 3.


Find number of decimal places in decimal value regardless of culture

Using recursion you can do:

private int GetDecimals(decimal n, int decimals = 0)  
    return n % 1 != 0 ? GetDecimals(n * 10, decimals + 1) : decimals;  

Copy/Paste from Excel to a web page

UPDATE: This is only true if you use ONLYOFFICE instead of MS Excel.

There is actually a flow in all answers provided here and also in the accepted one. The flow is that whenever you have an empty cell in excel and copy that, in the clipboard you have 2 tab chars next to each other, so after splitting you get one additional item in array, which then appears as an extra cell in that row and moves all other cells by one. So to avoid that you basically need to replace all double tab (tabs next to each other only) chars in a string with one tab char and only then split it.

An updated version of @userfuser's jsfiddle is here to fix that issue by filtering pasted data with removeExtraTabs

function removeExtraTabs(string) {
  return string.replace(new RegExp("\t\t", 'g'), "\t");

function generateTable() {
  var data = removeExtraTabs($('#pastein').val());
  var rows = data.split("\n");
  var table = $('<table />');

  for (var y in rows) {
    var cells = rows[y].split("\t");
    var row = $('<tr />');
    for (var x in cells) {
      row.append('<td>' + cells[x] + '</td>');

  // Insert into DOM

$(document).ready(function() {
  $('#pastein').on('paste', function(event) {
    $('#pastein').on('input', function() {

javascript: Disable Text Select

For JavaScript use this function:

function disableselect(e) {return false}
document.onselectstart = new Function (return false)
document.onmousedown = disableselect

to enable the selection use this:

function reEnable() {return true}

and use this function anywhere you want:

document.onclick = reEnable