Programs & Examples On #Getelementsbytagname

A native HTML DOM Element method used to get all elements with the specified tag name.

Xml Parsing in C#

First add an Enrty and Category class:

public class Entry {     public string Id { get; set; }     public string Title { get; set; }     public string Updated { get; set; }     public string Summary { get; set; }     public string GPoint { get; set; }     public string GElev { get; set; }     public List<string> Categories { get; set; } }  public class Category {     public string Label { get; set; }     public string Term { get; set; } } 

Then use LINQ to XML

XDocument xDoc = XDocument.Load("path");          List<Entry> entries = (from x in xDoc.Descendants("entry")             select new Entry()             {                 Id = (string) x.Element("id"),                 Title = (string)x.Element("title"),                 Updated = (string)x.Element("updated"),                 Summary = (string)x.Element("summary"),                 GPoint = (string)x.Element("georss:point"),                 GElev = (string)x.Element("georss:elev"),                 Categories = (from c in x.Elements("category")                                   select new Category                                   {                                       Label = (string)c.Attribute("label"),                                       Term = (string)c.Attribute("term")                                   }).ToList();             }).ToList(); 

Chrome violation : [Violation] Handler took 83ms of runtime

It seems you have found your solution, but still it will be helpful to others, on this page on point based on Chrome 59.

4.Note the red triangle in the top-right of the Animation Frame Fired event. Whenever you see a red triangle, it's a warning that there may be an issue related to this event.

If you hover on these triangle you can see those are the violation handler errors and as per point 4. yes there is some issue related to that event.

Attach event to dynamic elements in javascript

I've made a simple function for this.

The _case function allows you to not only get the target, but also get the parent element where you bind the event on.

The callback function returns the event which holds the target ( and the parent element matching the selector (this). Here you can do the stuff you need after the element is clicked.

I've not yet decided which is better, the if-else or the switch

var _case = function(evt, selector, cb) {_x000D_
  var _this =;_x000D_
  if (_this && _this.nodeType) {_x000D_, evt);_x000D_
    return true;_x000D_
  } else { return false; }_x000D_
document.getElementById('ifelse').addEventListener('click', function(evt) {_x000D_
  if (_case(evt, '.parent1', function(evt) {_x000D_
      console.log('1: ', this,;_x000D_
    })) return false;_x000D_
  if (_case(evt, '.parent2', function(evt) {_x000D_
      console.log('2: ', this,;_x000D_
    })) return false;_x000D_
  console.log('ifelse: ', this);_x000D_
document.getElementById('switch').addEventListener('click', function(evt) {_x000D_
  switch (true) {_x000D_
    case _case(evt, '.parent3', function(evt) {_x000D_
      console.log('3: ', this,;_x000D_
    }): break;_x000D_
    case _case(evt, '.parent4', function(evt) {_x000D_
      console.log('4: ', this,;_x000D_
    }): break;_x000D_
      console.log('switch: ', this);_x000D_
#ifelse {_x000D_
  background: red;_x000D_
  height: 100px;_x000D_
#switch {_x000D_
  background: yellow;_x000D_
  height: 100px;_x000D_
<div id="ifelse">_x000D_
  <div class="parent1">_x000D_
    <div class="child1">Click me 1!</div>_x000D_
  <div class="parent2">_x000D_
    <div class="child2">Click me 2!</div>_x000D_
<div id="switch">_x000D_
  <div class="parent3">_x000D_
    <div class="child3">Click me 3!</div>_x000D_
  <div class="parent4">_x000D_
    <div class="child4">Click me 4!</div>_x000D_

Hope it helps!

Code not running in IE 11, works fine in Chrome

text.indexOf("newString") is the best method instead of startsWith.


var text = "Format";
if(text.indexOf("Format") == 0) {
    alert(text + " = Format");
} else {
    alert(text + " != Format");

Use Excel VBA to click on a button in Internet Explorer, when the button has no "name" associated


EDIT: to loop through the collection (items should appear in the same order as they are in the source document)

Dim links, link 

Set links = IE.Document.getElementById("dgTime").getElementsByTagName("a")

'For Each loop
For Each link in links
Next link

'For Next loop
Dim n, i
n = links.length
For i = 0 to n-1 Step 2
Next I

How to check View Source in Mobile Browsers (Both Android && Feature Phone)

This question is a few years old, and there are some good suggestions for workarounds, but I didn't really notice any answers that address the core of the original question head-on. So:

  • Providing a "universal" method for viewing source in a feature phone browser (or even arbitrary third-party smartphone browser) is impossible because "view source" — via any method — is a feature implemented in the browser. So how it's accessed, or even if it can be accessed, is up to the developers of the browser. I'm sure there are plenty of browsers that intentionally prevent the user from viewing page source, and if so then you're out of luck, except maybe for workarounds like the ones offered here.

  • Workarounds such as "view source" apps external to the browser, while useful in some cases, are at best an imperfect partial solution to the original request. It's never certain that any such app will display the source of the page in the same form as it's loaded by the phone's browser.

    Modern web content changes itself in all manner of ways through browser detection, session management, etc. so that the source loaded by any external app can never be relied on to represent the source as loaded by a different app. If you're going to use an external app to load a page because you want to see the source, you might as well just use Chrome (or, on an iOS device, Safari) instead.

ReferenceError: document is not defined (in plain JavaScript)

This happened with me because I was using Next JS which has server side rendering. When you are using server side rendering there is no browser. Hence, there will not be any variable window or document. Hence this error shows up.

Work around :

If you are using Next JS you can use the dynamic rendering to prevent server side rendering for the component.

import dynamic from 'next/dynamic'

const DynamicComponentWithNoSSR = dynamic(() => import('../components/List'), {
  ssr: false

export default () => <DynamicComponentWithNoSSR />

If you are using any other server side rendering library. Then add the code that you want to run at the client side in componentDidMount. If you are using React Hooks then use useEffects in the place of componentsDidMount.

import React, {useState, useEffects} from 'react';

const DynamicComponentWithNoSSR = <>Some JSX</>

export default function App(){

[a,setA] = useState();
useEffect(() => {

return (<>{a}<>)

References :


Failed to execute 'atob' on 'Window'

you don't need to pass the entire encoded string to atob method, you need to split the encoded string and pass the required string to atob method

const token= "eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiJob3NzYW0iLCJUb2tlblR5cGUiOiJCZWFyZXIiLCJyb2xlIjoiQURNSU4iLCJpc0FkbWluIjp0cnVlLCJFbXBsb3llZUlkIjoxLCJleHAiOjE2MTI5NDA2NTksImlhdCI6MTYxMjkzNzA1OX0.8f0EeYbGyxt9hjggYW1vR5hMHFVXL4ZvjTA6XgCCAUnvacx_Dhbu1OGh8v5fCsCxXQnJ8iAIZDIgOAIeE55LUw"

Check/Uncheck all the checkboxes in a table


Add onClick event to checkbox where you want, like below.

<input type="checkbox" onClick="selectall(this)"/>Select All<br/>
<input type="checkbox" name="foo" value="make">Make<br/>
<input type="checkbox" name="foo" value="model">Model<br/>
<input type="checkbox" name="foo" value="descr">Description<br/>
<input type="checkbox" name="foo" value="startYr">Start Year<br/>
<input type="checkbox" name="foo" value="endYr">End Year<br/>

In JavaScript you can write selectall function as

function selectall(source) {
  checkboxes = document.getElementsByName('foo');
  for(var i=0, n=checkboxes.length;i<n;i++) {
    checkboxes[i].checked = source.checked;

Get Selected value from dropdown using JavaScript

The first thing i noticed is that you have a semi colon just after your closing bracket for your if statement );

You should also try and clean up your if statement by declaring a variable for the answer separately.

function answers() {

var select = document.getElementById("mySelect");
var answer = select.options[select.selectedIndex].value;

    if(answer == "To measure time"){
        alert("Thats correct"); 


How to check file MIME type with javascript before upload?

If you just want to check if the file uploaded is an image you can just try to load it into <img> tag an check for any error callback.


var input = document.getElementsByTagName('input')[0];
var reader = new FileReader();

reader.onload = function (e) {
    imageExists(, function(exists){
        if (exists) {

            // Do something with the image file.. 

        } else {

            // different file format



function imageExists(url, callback) {
    var img = new Image();
    img.onload = function() { callback(true); };
    img.onerror = function() { callback(false); };
    img.src = url;

Creating a Shopping Cart using only HTML/JavaScript

For a project this size, you should stop writing pure JavaScript and turn to some of the libraries available. I'd recommend jQuery (, which allows you to select elements by css-selectors, which I recon should speed up your development quite a bit.

Example of your code then becomes;

function AddtoCart() {
  var len = $("#Items tr").length, $row, $inp1, $inp2, $cells;

  $row = $("#Items td:first").clone(true);
  $cells = $row.find("td");

  $cells.get(0).html( len );

  $inp1 = $cells.get(1).find("input:first");
  $inp1.attr("id", $inp1.attr("id") + len).val("");

  $inp2 = $cells.get(2).find("input:first");
  $inp2.attr("id", $inp2.attr("id") + len).val("");


I can see that you might not understand that code yet, but take a look at jQuery, it's easy to learn and will make this development way faster.

I would use the libraries already created specifically for js shopping carts if I were you though.

To your problem; If i look at your jsFiddle, it doesn't even seem like you have defined a table with the id Items? Maybe that's why it doesn't work?

Resize svg when window is resized in d3.js

Use window.onresize:

function updateWindow(){
    x = w.innerWidth || e.clientWidth || g.clientWidth;
    y = w.innerHeight|| e.clientHeight|| g.clientHeight;

    svg.attr("width", x).attr("height", y);
}'resize.updatesvg', updateWindow);

How to get a reference to an iframe's window object inside iframe's onload handler created from parent window

You're declaring everything in the parent page. So the references to window and document are to the parent page's. If you want to do stuff to the iframe's, use iframe || iframe.contentWindow to access its window, and iframe.contentDocument || iframe.contentWindow.document to access its document.

There's a word for what's happening, possibly "lexical scope": What is lexical scope?

The only context of a scope is this. And in your example, the owner of the method is doc, which is the iframe's document. Other than that, anything that's accessed in this function that uses known objects are the parent's (if not declared in the function). It would be a different story if the function were declared in a different place, but it's declared in the parent page.

This is how I would write it:

(function () {
  var dom, win, doc, where, iframe;

  iframe = document.createElement('iframe');
  iframe.src = "javascript:false";

  where = document.getElementsByTagName('script')[0];
  where.parentNode.insertBefore(iframe, where);

  win = iframe.contentWindow || iframe;
  doc = iframe.contentDocument || iframe.contentWindow.document;;
  doc._l = (function (w, d) {
    return function () {
      w.vanishing_global = new Date().getTime();

      var js = d.createElement("script");
      js.src = 'test-vanishing-global.js?' + w.vanishing_global; = "foobar";
      d.foobar = "foobar:" + Math.random();
      d.foobar = "barfoo:" + Math.random();
  })(win, doc);
  doc.write('<body onload="document._l();"></body>');

The aliasing of win and doc as w and d aren't necessary, it just might make it less confusing because of the misunderstanding of scopes. This way, they are parameters and you have to reference them to access the iframe's stuff. If you want to access the parent's, you still use window and document.

I'm not sure what the implications are of adding methods to a document (doc in this case), but it might make more sense to set the _l method on win. That way, things can be run without a prefix...such as <body onload="_l();"></body>

how to get files from <input type='file' .../> (Indirect) with javascript

Based on Ray Nicholus's answer :

inputElement.onchange = function(event) {
   var fileList = inputElement.files;
   //TODO do something with fileList.  

using this will also work :

inputElement.onchange = function(event) {
   var fileList =;
   //TODO do something with fileList.  

Playing HTML5 video on fullscreen in android webview

It seems that in lollipop and up (or maybe just a different WebView Version) that calling cprcrack's onHideCustomView() method does not work. It works if it is called from the exit fullscreen button but when you specifically call the method it will only exit fullscreen but the webView stays blank. A way around it is to simply add these lines of code to onHideCustomView():

String js = "javascript:";
js += "var _ytrp_html5_video = document.getElementsByTagName('video')[0];";
js += "_ytrp_html5_video.webkitExitFullscreen();";

This will notify the webView that fullscreen has exited.

Adding div element to body or document in JavaScript

The modern way is to use ParentNode.append(), like so:

let element = document.createElement('div');_x000D_ = 'position:absolute;width:100%;height:100%;opacity:0.3;z-index:100;background:#000;';_x000D_

how to disable DIV element and everything inside

Try this!

$("#test *").attr("disabled", "disabled").off('click');

I don't see you using jquery above, but you have it listed as a tag.

How to fix Invalid byte 1 of 1-byte UTF-8 sequence

This error comes when you are trying to load jasper report file with the extension .jasper
For Example 

While you should load jasper report file with the extension .jrxml
For Example 
[See Problem Screenshot ][1] [1]:
[See Solution Screenshot][2] [2]:


Use getElementById on HTMLElement instead of HTMLDocument

I would use XMLHTTP request to retrieve page content as much faster. Then it is easy enough to use querySelectorAll to apply a CSS class selector to grab by class name. Then you access the child elements by tag name and index.

Option Explicit
Public Sub GetInfo()
    Dim sResponse As String, html As HTMLDocument, elements As Object, i As Long

    With CreateObject("MSXML2.XMLHTTP")
        .Open "GET", "", False
        .setRequestHeader "If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT"
        sResponse = StrConv(.responseBody, vbUnicode)
    End With
    Set html = New HTMLDocument
    With html
        .body.innerHTML = sResponse
        Set elements = .querySelectorAll(".profile-col1")
        For i = 0 To elements.Length - 1
            Debug.Print String(20, Chr$(61))
            Debug.Print elements.item(i).getElementsByTagName("a")(0).innerText
            Debug.Print elements.item(i).getElementsByTagName("p")(0).innerText
            Debug.Print elements.item(i).getElementsByTagName("p")(1).innerText
    End With
End Sub


VBE > Tools > References > Microsoft HTML Object Library

Create table using Javascript

        background: radial-gradient(rgba(179,255,0.5),rgba(255,255,255,0.5),rgba(0,0,0,0.2));
        text-align: center;
        margin-top: 50px;
        font-size: 25px;
        color: #004d00;
        font-weight: 700;
        font-family: cursive;
        width: 150px;
        height: 40px;
        font-size: 23px;
        font-family:  cursive;
        background-color: #001a66;
        color: whitesmoke;
        box-shadow: 0 2px 2px 0 rgba(0,0,0,0.5);
        margin: 20px;
        border-collapse: collapse;
        width: 50%;
        margin: 50px auto;
        background-color: burlywood;
       border: 2px solid black;

        font-size: 30px;
        font-weight: 700;
        font-family: Arial;
        color: #004d00;
        font-size: 25px;
        color: crimson;
        font-weight: 400;
        font-family: Georgia;
        width: 20%;
    <!-- Code to get student details -->
    <div id="container" >
        <div class="input">
             Name: <input type="text" id="name" class="length" placeholder="eg: Anil Ambani"/>
        <div class="input">
             Email: <input type="text" id="mail" class="length" placeholder="eg: [email protected]"/>
        <div class="input">
             Phone: <input type="text" id="phn"  class="length" placeholder="eg: 9898989898"/>
        <div class="input">
             SLNO: <input type="number" id="sln" class="length" placeholder="eg: 1"/>
        <button id="entry"> I/P ENTRY</button>
    <table id="tabledata">
          <th> Name</th>
          <th> Email</th>
          <th> Phone</th>
          <th> Slno</th>
    var entry = document.getElementById('entry');
    var row = 1;
    function display(){
        var nam =  document.getElementById('name').value;
        var emal = document.getElementById('mail').value;
        var ph = document.getElementById('phn').value;
        var sl = document.getElementById('sln').value;
        var disp = document.getElementById("tabledata");
        var newRow = disp.insertRow(row);
        var cell1 = newRow.insertCell(0);
        var cell2 = newRow.insertCell(1);
        var cell3 = newRow.insertCell(2);
        var cell4 = newRow.insertCell(3);
        cell1.innerHTML = nam;
        cell2.innerHTML = emal;
        cell3.innerHTML = ph;
        cell4.innerHTML = sl;

Loop through all elements in XML using NodeList

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document dom = db.parse("file.xml");
    Element docEle = dom.getDocumentElement();
    NodeList nl = docEle.getChildNodes();
    int length = nl.getLength();
    for (int i = 0; i < length; i++) {
        if (nl.item(i).getNodeType() == Node.ELEMENT_NODE) {
            Element el = (Element) nl.item(i);
            if (el.getNodeName().contains("staff")) {
                String name = el.getElementsByTagName("name").item(0).getTextContent();
                String phone = el.getElementsByTagName("phone").item(0).getTextContent();
                String email = el.getElementsByTagName("email").item(0).getTextContent();
                String area = el.getElementsByTagName("area").item(0).getTextContent();
                String city = el.getElementsByTagName("city").item(0).getTextContent();

Iterate over all children and nl.item(i).getNodeType() == Node.ELEMENT_NODE is used to filter text nodes out. If there is nothing else in XML what remains are staff nodes.

For each node under stuff (name, phone, email, area, city)


el.getElementsByTagName("name") will extract the "name" nodes under stuff, .item(0) will get you the first node and .getTextContent() will get the text content inside.

Edit: Since we have jackson I would do this in a different way. Define a pojo for the object:

public class Staff {
    private String name;
    private String phone;
    private String email;
    private String area;
    private String city;
...getters setters

Then using jackson:

    JsonNode root = new XmlMapper().readTree(xml.getBytes());
    ObjectMapper mapper = new ObjectMapper();
    root.forEach(node -> consume(node, mapper));

private void consume(JsonNode node, ObjectMapper mapper) {
    try {
        Staff staff = mapper.treeToValue(node, Staff.class);
        //TODO your job with staff
    } catch (JsonProcessingException e) {

Given URL is not permitted by the application configuration

Update to Anvesh Saxena's answer(correct but outdated as FB App interface has changed):

In your FB App configuration you need to add a Website platform with your website's URL set. Then you can add App Domains which I set to our website's base domain (e.g. for a URL like, just use

New FB Settings Screenshot

IMPORTANT: In order for this to work you'll need to be using a subdomain of your app's URL for your local development. You can do this easily by modifying your hosts file on your development computer to use a non-existent subdomain of your website such as Just google 'edit hosts file' for your platform (e.g. mac / windows) if you're not familiar with how to do this.

Javascript Error Null is not an Object

I think the error because the elements are undefined ,so you need to add window.onload event which this event will defined your elements when the window is loaded.


    function Loaded(){
    var myButton = document.getElementById("myButton");
    var myTextfield = document.getElementById("myTextfield");

    function greetUser(userName) {
    var greeting = "Hello " + userName + "!";
    document.getElementsByTagName ("h2")[0].innerHTML = greeting;

    myButton.onclick = function() {
    var userName = myTextfield.value;

    return false;

Create <div> and append <div> dynamically

var iDiv = document.createElement('div'),
    jDiv = document.createElement('div'); = 'block';
iDiv.className = 'block';
jDiv.className = 'block-2';

How get total sum from input box values using Javascript?


window.sumInputs = function() {
    var inputs = document.getElementsByTagName('input'),
        result = document.getElementById('total'),
        sum = 0;            

    for(var i=0; i<inputs.length; i++) {
        var ip = inputs[i];

        if ( &&"total") < 0) {
            sum += parseInt(ip.value) || 0;


    result.value = sum;


Qty1 : <input type="text" name="qty1" id="qty"/><br>
Qty2 : <input type="text" name="qty2" id="qty"/><br>
Qty3 : <input type="text" name="qty3" id="qty"/><br>
Qty4 : <input type="text" name="qty4" id="qty"/><br>
Qty5 : <input type="text" name="qty5" id="qty"/><br>
Qty6 : <input type="text" name="qty6" id="qty"/><br
Qty7 : <input type="text" name="qty7" id="qty"/><br>
Qty8 : <input type="text" name="qty8" id="qty"/><br>
Total : <input type="text" name="total" id="total"/>

<a href="javascript:sumInputs()">Sum</a>



Call Python function from JavaScript code

All you need is to make an ajax request to your pythoncode. You can do this with jquery, or use just javascript

  type: "POST",
  url: "~/",
  data: { param: text}
}).done(function( o ) {
   // do something

How to get child element by class name?

You could try:

notes = doc.querySelectorAll('.4');


notes = doc.getElementsByTagName('*');
for (var i = 0; i < notes.length; i++) { 
    if (notes[i].getAttribute('class') == '4') {

how to get the attribute value of an xml node using java


document.getElementsByTagName(" * ");

to get all XML elements from within an XML file, this does however return repeating attributes


NodeList list = doc.getElementsByTagName("*");

System.out.println("XML Elements: ");

        for (int i=0; i<list.getLength(); i++) {

            Element element = (Element)list.item(i);

Getting the source HTML of the current page from chrome extension

Inject a script into the page you want to get the source from and message it back to the popup....


  "name": "Get pages source",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Get pages source from a popup",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  "permissions": ["tabs", "<all_urls>"]


<!DOCTYPE html>
<html style=''>
<script src='popup.js'></script>
<body style="width:400px;">
<div id='message'>Injecting Script....</div>


chrome.runtime.onMessage.addListener(function(request, sender) {
  if (request.action == "getSource") {
    message.innerText = request.source;

function onWindowLoad() {

  var message = document.querySelector('#message');

  chrome.tabs.executeScript(null, {
    file: "getPagesSource.js"
  }, function() {
    // If you try and inject into an extensions page or the webstore/NTP you'll get an error
    if (chrome.runtime.lastError) {
      message.innerText = 'There was an error injecting script : \n' + chrome.runtime.lastError.message;


window.onload = onWindowLoad;


// @author Rob W <>
// Demo: var serialized_html = DOMtoString(document);

function DOMtoString(document_root) {
    var html = '',
        node = document_root.firstChild;
    while (node) {
        switch (node.nodeType) {
        case Node.ELEMENT_NODE:
            html += node.outerHTML;
        case Node.TEXT_NODE:
            html += node.nodeValue;
        case Node.CDATA_SECTION_NODE:
            html += '<![CDATA[' + node.nodeValue + ']]>';
        case Node.COMMENT_NODE:
            html += '<!--' + node.nodeValue + '-->';
        case Node.DOCUMENT_TYPE_NODE:
            // (X)HTML documents are identified by public identifiers
            html += "<!DOCTYPE " + + (node.publicId ? ' PUBLIC "' + node.publicId + '"' : '') + (!node.publicId && node.systemId ? ' SYSTEM' : '') + (node.systemId ? ' "' + node.systemId + '"' : '') + '>\n';
        node = node.nextSibling;
    return html;

    action: "getSource",
    source: DOMtoString(document)

Check file size before upload

I created a jQuery version of PhpMyCoder's answer:

$('form').submit(function( e ) {    
    if(!($('#file')[0].files[0].size < 10485760 && get_extension($('#file').val()) == 'jpg')) { // 10 MB (this size is in bytes)
        //Prevent default and display error
        alert("File is wrong type or over 10Mb in size!");

function get_extension(filename) {
    return filename.split('.').pop().toLowerCase();

Change :hover CSS properties with JavaScript

If it fits your purpose you can add the hover functionality without using css and using the onmouseover event in javascript

Here is a code snippet

<div id="mydiv">foo</div>

document.getElementById("mydiv").onmouseover = function() 
{ = "blue";

Image re-size to 50% of original size in HTML

We can do this by css3 too. Try this:

.halfsize {

<img class="halfsize" src="image4.jpg">
  • subjected to browser compatibility

Alternative to header("Content-type: text/xml");

Now I see what you are doing. You cannot send output to the screen then change the headers. If you are trying to create an XML file of map marker and download them to display, they should be in separate files.

Take this

function parseToXML($htmlStr)
return $xmlStr;
// Opens a connection to a MySQL server
$connection=mysql_connect (localhost, $username, $password);
if (!$connection) {
  die('Not connected : ' . mysql_error());
// Set the active MySQL database
$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
  die ('Can\'t use db : ' . mysql_error());
// Select all the rows in the markers table
$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {
  die('Invalid query: ' . mysql_error());
header("Content-type: text/xml");
// Start XML file, echo parent node
echo '<markers>';
// Iterate through the rows, printing XML nodes for each
while ($row = @mysql_fetch_assoc($result)){
  echo '<marker ';
  echo 'name="' . parseToXML($row['name']) . '" ';
  echo 'address="' . parseToXML($row['address']) . '" ';
  echo 'lat="' . $row['lat'] . '" ';
  echo 'lng="' . $row['lng'] . '" ';
  echo 'type="' . $row['type'] . '" ';
  echo '/>';
// End XML file
echo '</markers>';

and place it in phpsqlajax_genxml.php so your javascript can download the XML file. You are trying to do too many things in the same file.

Hexadecimal value 0x00 is a invalid character

As kind of a late answer:

I've had this problem with SSRS ReportService2005.asmx when uploading a report.

    Public Shared Sub CreateReport(ByVal strFileNameAndPath As String, ByVal strReportName As String, ByVal strReportingPath As String, Optional ByVal bOverwrite As Boolean = True)
        Dim rs As SSRS_2005_Administration_WithFOA = New SSRS_2005_Administration_WithFOA
        rs.Credentials = ReportingServiceInterface.GetMyCredentials(strCredentialsURL)
        rs.Timeout = ReportingServiceInterface.iTimeout
        rs.Url = ReportingServiceInterface.strReportingServiceURL
        rs.UnsafeAuthenticatedConnectionSharing = True

        Dim btBuffer As Byte() = Nothing

        Dim rsWarnings As Warning() = Nothing
            Dim fstrStream As System.IO.FileStream = System.IO.File.OpenRead(strFileNameAndPath)
            btBuffer = New Byte(fstrStream.Length - 1) {}
            fstrStream.Read(btBuffer, 0, CInt(fstrStream.Length))
        Catch ex As System.IO.IOException
            Throw New Exception(ex.Message)
        End Try

            rsWarnings = rs.CreateReport(strReportName, strReportingPath, bOverwrite, btBuffer, Nothing)

            If Not (rsWarnings Is Nothing) Then
                Dim warning As Warning
                For Each warning In rsWarnings
                Next warning
                Log("Report: {0} created successfully with no warnings", strReportName)
            End If

        Catch ex As System.Web.Services.Protocols.SoapException
        Catch ex As Exception
            Log("Error at creating report. Invalid server name/timeout?" + vbCrLf + vbCrLf + "Error Description: " + vbCrLf + ex.Message)
        End Try
    End Sub ' End Function CreateThisReport

The problem occurs when you allocate a byte array that is at least 1 byte larger than the RDL (XML) file.

Specifically, I used a C# to converter, that converted

  btBuffer = new byte[fstrStream.Length];


  btBuffer = New Byte(fstrStream.Length) {}

But because in C# the number denotes the NUMBER OF ELEMENTS in the array, and in VB.NET, that number denotes the UPPER BOUND of the array, I had an excess byte, causing this error.

So the problem's solution is simply:

  btBuffer = New Byte(fstrStream.Length - 1) {}

Uncaught syntaxerror: unexpected identifier?

There are errors here :

var formTag = document.getElementsByTagName("form"), // form tag is an array
selectListItem = $('select'),
makeSelect = document.createElement('select'),
makeSelect.setAttribute("id", "groups");

The code must change to:

var formTag = document.getElementsByTagName("form");
var selectListItem = $('select');
var makeSelect = document.createElement('select');
makeSelect.setAttribute("id", "groups");

By the way, there is another error at line 129 :

var createLi.appendChild(createSubList);

Replace it with:


How do I change an HTML selected option using JavaScript?

It's an old post, but if anyone is still looking for solution to this kind of problem, here is what I came up with:

  document.addEventListener("DOMContentLoaded", function(e) {
    document.forms['AddAndEdit'].elements['list'].value = 11;

How to maintain page scroll position after a jquery event is carried out?

I had a similar problem getting scrollTop to work after reload of div content. The content scrolled to top each time the procedure below was run. I found that a little delay before setting the new scrolltop solved the issue.

This is cut from wdCalendar where I modified this procedure:

 function BuildDaysAndWeekView(startday, l, events, config)
        var scrollpos = $("#dvtec").scrollTop();
        setTimeout(function() {
        }, 25);

Without the delay, it simply did not work.

JavaScript get child element

I'd suggest doing something similar to:

function show_sub(cat) {
    if (!cat) {
        return false;
    else if (document.getElementById(cat)) {
        var parent = document.getElementById(cat),
            sub = parent.getElementsByClassName('sub');
        if (sub[0].style.display == 'inline'){
            sub[0].style.display = 'none';
        else {
            sub[0].style.display = 'inline';

document.getElementById('cat').onclick = function(){

JS Fiddle demo.

Though the above relies on the use of a class rather than a name attribute equal to sub.

As to why your original version "didn't work" (not, I must add, a particularly useful description of the problem), all I can suggest is that, in Chromium, the JavaScript console reported that:

Uncaught TypeError: Object # has no method 'getElementsByName'.

One approach to working around the older-IE family's limitations is to use a custom function to emulate getElementsByClassName(), albeit crudely:

function eBCN(elem,classN){
    if (!elem || !classN){
        return false;
    else {
        var children = elem.childNodes;
        for (var i=0,len=children.length;i<len;i++){
            if (children[i].nodeType == 1
                children[i].className == classN){
                    var sub = children[i];
        return sub;

function show_sub(cat) {
    if (!cat) {
        return false;
    else if (document.getElementById(cat)) {
        var parent = document.getElementById(cat),
            sub = eBCN(parent,'sub');
        if ( == 'inline'){
   = 'none';
        else {
   = 'inline';

var D = document,
    listElems = D.getElementsByTagName('li');
for (var i=0,len=listElems.length;i<len;i++){
    listElems[i].onclick = function(){

JS Fiddle demo.

Root element is missing

  1. Check the trees.config file which located in config folder... sometimes (I don't know why) this file became to be empty like someone delete the content inside... keep backup up of this file in your local pc then when this error appear - replace the server file with your local file. This is what i do when this error happened.

  2. check the available space on the server. sometimes this is the problem.

Good luck.

Load jQuery with Javascript and use jQuery




    <div id='status'>jQuery is not loaded yet.</div>
    <input type='button' value='Click here to load it.' onclick='load()' />




        load = function() {
          load.tryReady(0); // We will write this function later. It's responsible for waiting until jQuery loads before using it.

        // dynamically load any javascript file.
        load.getScript = function(filename) {
          var script = document.createElement('script')
          script.setAttribute("src", filename)
          if (typeof script!="undefined")


Count number of columns in a table row

It's a bad idea to count the td elements to get the number of columns in your table, because td elements can span multiple columns with colspan.

Here's a simple solution using jquery:

var length = 0;_x000D_
 var colspan = $(this).attr("colspan");_x000D_
  if(typeof colspan !== "undefined" && colspan > 0){_x000D_
   length += parseInt(colspan);_x000D_
        length += 1;_x000D_
$("div").html("number of columns: "+length);
<script src=""></script>_x000D_
  <td colspan="2">double</td>_x000D_

For a plain Javascript solution, see Emilio's answer.

Show ProgressDialog Android

I am using the following code in one of my current projects where i download data from the internet. It is all inside my activity class.

private class GetData extends AsyncTask<String, Void, JSONObject> {

        protected void onPreExecute() {

            progressDialog =,
                    "", "");


        protected JSONObject doInBackground(String... params) {

            String response;

            try {

                HttpClient httpclient = new DefaultHttpClient();

                HttpPost httppost = new HttpPost(url);

                HttpResponse responce = httpclient.execute(httppost);

                HttpEntity httpEntity = responce.getEntity();

                response = EntityUtils.toString(httpEntity);

                Log.d("response is", response);

                return new JSONObject(response);

            } catch (Exception ex) {



            return null;

        protected void onPostExecute(JSONObject result) 


            if(result != null)
                    JSONObject jobj = result.getJSONObject("result");

                    String status = jobj.getString("status");

                        JSONArray array = jobj.getJSONArray("data");

                        for(int x = 0; x < array.length(); x++)
                            HashMap<String, String> map = new HashMap<String, String>();

                            map.put("name", array.getJSONObject(x).getString("name"));

                            map.put("date", array.getJSONObject(x).getString("date"));

                            map.put("description", array.getJSONObject(x).getString("description"));


                        CalendarAdapter adapter = new CalendarAdapter(Calendar.this, list);

                catch (Exception e) 
                Toast.makeText(Calendar.this, "Network Problem", Toast.LENGTH_LONG).show();


and execute it in OnCreate Method like new GetData().execute();

where Calendar is my calendarActivity and i have also created a CalendarAdapter to set these values to a list view.

Detect if HTML5 Video element is playing

It seems to me like you could just check for !stream.paused.

Padding is invalid and cannot be removed?

I came across this as a regression bug when refactoring code from traditional using blocks to the new C# 8.0 using declaration style, where the block ends when the variable falls out of scope at the end of the method.

Old style:

using (MemoryStream ms = new MemoryStream())
    using (CryptoStream cs = new CryptoStream(ms, aesCrypto.CreateDecryptor(), CryptoStreamMode.Write))
        cs.Write(rawCipherText, 0, rawCipherText.Length);

    return Encoding.Unicode.GetString(ms.ToArray());

New, less indented style:

using MemoryStream ms = new MemoryStream();
using CryptoStream cs = new CryptoStream(ms, aesCrypto.CreateDecryptor(), CryptoStreamMode.Write);

cs.Write(rawCipherText, 0, rawCipherText.Length);

return Encoding.Unicode.GetString(ms.ToArray());

With the old style, the using block for the CryptoStream terminated and the finalizer was called before memory stream gets read in the return statement, so the CryptoStream was automatically flushed.

With the new style, the memory stream is read before the CryptoStream finalizer gets called, so I had to manually call FlushFinalBlock() before reading from the memory stream in order to fix this issue. I had to manually flush the final block for both the encrypt and the decrypt methods, when they were written in the new using style.

How to select <td> of the <table> with javascript?

There are a lot of ways to accomplish this, and this is but one of them.

$("table").find("tbody td").eq(0).children().first()

Read a XML (from a string) and get some fields - Problems reading XML

Or use the XmlSerializer class.

XmlSerializer xs = new XmlSerializer(objectType);
obj = xs.Deserialize(new StringReader(yourXmlString));

PHP DOMDocument loadHTML not encoding UTF-8 correctly

The problem is with saveHTML() and saveXML(), both of them do not work correctly in Unix. They do not save UTF-8 characters correctly when used in Unix, but they work in Windows.

The workaround is very simple:

If you try the default, you will get the error you described

$str = $dom->saveHTML(); // saves incorrectly

All you have to do is save as follows:

$str = $dom->saveHTML($dom->documentElement); // saves correctly

This line of code will get your UTF-8 characters to be saved correctly. Use the same workaround if you are using saveXML().


As suggested by "Jack M" in the comments section below, and verified by "Pamela" and "Marco Aurélio Deleu", the following variation might work in your case:

$str = utf8_decode($dom->saveHTML($dom->documentElement));


  1. English characters do not cause any problem when you use saveHTML() without parameters (because English characters are saved as single byte characters in UTF-8)

  2. The problem happens when you have multi-byte characters (such as Chinese, Russian, Arabic, Hebrew, ...etc.)

I recommend reading this article: You will understand how UTF-8 works and why you have this problem. It will take you about 30 minutes, but it is time well spent.

how to get html content from a webview?

Why not get the html first then pass it to the web view?

private String getHtml(String url){
    HttpGet pageGet = new HttpGet(url);

    ResponseHandler<String> handler = new ResponseHandler<String>() {
        public String handleResponse(HttpResponse response) throws ClientProtocolException, IOException {
            HttpEntity entity = response.getEntity();
            String html; 

            if (entity != null) {
                html = EntityUtils.toString(entity);
                return html;
            } else {
                return null;

    pageHTML = null;
    try {
        while (pageHTML==null){
            pageHTML = client.execute(pageGet, handler);
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block

    return pageHTML;

public void customizeWebView(final ServiceCommunicableActivity activity, final WebView webview, final SearchResult mRom) {
    WebViewClient anchorWebViewClient = new WebViewClient()

        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);

            //Do what you want to with the html
            String html = getHTML(url);

            if( html!=null && !url.equals(lastLoadedURL)){
                lastLoadedURL = url;
                webview.loadDataWithBaseURL(url, html, null, "utf-8", url);

This should roughly do what you want to do. It is adapted from Is it possible to get the HTML code from WebView and shout out to for his answer.

Facebook Open Graph Error - Inferred Property

UPD 2020: "Open Graph Object Debugger" has been discontinued. Use Sharing Debugger to refresh Facebook cache.

There is some confusion about tons of Facebook Tools and Documentation. So many people probably use the Sharing Debugger tool to check their OpenGraph markup:

But it only retrieves the information about your site from the Facebook cache. This means that after you change the ogp-markup on your site, the Sharing Debugger will still be using the old cached data. Moreover, if there is no cached data on the Facebook server then the Sharing Debugger will show you the error: This URL hasn't been shared on Facebook before.

So, the solution is to use another tool – Open Graph Object Debugger:

It allows you to Fetch new scrape information and refresh the Facebook cache:

Open Graph Object Debugger

Honestly, I don't know how to find this tool exploring the Tools & Support section of – I cannot find any links and mentions. I only have this tool in my bookmarks. That's Facebook :)

Use 'property'-attrs

I also noted that some developers use the name attribute instead of property. Many parsers probably will process such tags properly, but according to The Open Graph protocol, we should use property, not name:

<meta property="og:url" content=""/>

Use full URLs

The last recommendation is to specify full URLs. For example, Facebook complains when you use relative URL in og:image. So use the full one:

<meta property="og:image" content=""/>

load scripts asynchronously

Here is a great contemporary solution to the asynchronous script loading though it only address the js script with async false.

There is a great article written in - Deep dive into the murky waters of script loading .

After considering many possible solutions, the author concluded that adding js scripts to the end of body element is the best possible way to avoid blocking page rendering by js scripts.

In the mean time, the author added another good alternate solution for those people who are desperate to load and execute scripts asynchronously.

Considering you've four scripts named script1.js, script2.js, script3.js, script4.js then you can do it with applying async = false:

].forEach(function(src) {
  var script = document.createElement('script');
  script.src = src;
  script.async = false;

Now, Spec says: Download together, execute in order as soon as all download.

Firefox < 3.6, Opera says: I have no idea what this “async” thing is, but it just so happens I execute scripts added via JS in the order they’re added.

Safari 5.0 says: I understand “async”, but don’t understand setting it to “false” with JS. I’ll execute your scripts as soon as they land, in whatever order.

IE < 10 says: No idea about “async”, but there is a workaround using “onreadystatechange”.

Everything else says: I’m your friend, we’re going to do this by the book.

Now, the full code with IE < 10 workaround:

var scripts = [
var src;
var script;
var pendingScripts = [];
var firstScript = document.scripts[0];

// Watch scripts load in IE
function stateChange() {
  // Execute as many scripts in order as we can
  var pendingScript;
  while (pendingScripts[0] && ( pendingScripts[0].readyState == 'loaded' || pendingScripts[0].readyState == 'complete' ) ) {
    pendingScript = pendingScripts.shift();
    // avoid future loading events from this script (eg, if src changes)
    pendingScript.onreadystatechange = null;
    // can't just appendChild, old IE bug if element isn't closed
    firstScript.parentNode.insertBefore(pendingScript, firstScript);

// loop through our script urls
while (src = scripts.shift()) {
  if ('async' in firstScript) { // modern browsers
    script = document.createElement('script');
    script.async = false;
    script.src = src;
  else if (firstScript.readyState) { // IE<10
    // create a script and add it to our todo pile
    script = document.createElement('script');
    // listen for state changes
    script.onreadystatechange = stateChange;
    // must set src AFTER adding onreadystatechange listener
    // else we’ll miss the loaded event for cached scripts
    script.src = src;
  else { // fall back to defer
    document.write('<script src="' + src + '" defer></'+'script>');

Getting HTML elements by their attribute names

With prototypejs :



Both return an array

How do you get the contextPath from JavaScript, the right way?

A Spring Boot with Thymeleaf solution could look like:

Lets say my context-path is /app/

In Thymeleaf you can get it via:

<script th:inline="javascript">
        let contextPath    = /*[[@{/}]]*/

How to export html table to excel using javascript

The reason the solution you found on the internet is no working is because of the line that starts var colCount. The variable mytable only has two elements being <thead> and <tbody>. The var colCount line is looking for all the elements within mytable that are <tr>. The best thing you can do is give an id to your <thead> and <tbody> and then grab all the values based on that. Say you had <thead id='headers'> :

function write_headers_to_excel() 

  var myTableHead = document.getElementById('headers');
  var rowCount = myTableHead.rows.length;
  var colCount = myTableHead.getElementsByTagName("tr")[0].getElementsByTagName("th").length; 

var ExcelApp = new ActiveXObject("Excel.Application");
var ExcelSheet = new ActiveXObject("Excel.Sheet");
ExcelSheet.Application.Visible = true;

for(var i=0; i<rowCount; i++) 
    for(var j=0; j<colCount; j++) 
        str= myTableHead.getElementsByTagName("tr")[i].getElementsByTagName("th")[j].innerHTML;
        ExcelSheet.ActiveSheet.Cells(i+1,j+1).Value = str;


and then do the same thing for the <tbody> tag.

EDIT: I would also highly recommend using jQuery. It would shorten this up to:

function write_to_excel() 
 var ExcelApp = new ActiveXObject("Excel.Application");
 var ExcelSheet = new ActiveXObject("Excel.Sheet");
 ExcelSheet.Application.Visible = true; 

  $('th, td').each(function(i){
    ExcelSheet.ActiveSheet.Cells(i+1,i+1).Value = this.innerHTML;

Now, of course, this is going to give you some formatting issues but you can work out how you want it formatted in Excel.

EDIT: To answer your question about how to do this for n number of tables, the jQuery will do this already. To do it in raw Javascript, grab all the tables and then alter the function to be able to pass in the table as a parameter. For instance:

var tables = document.getElementsByTagName('table');
for(var i = 0; i < tables.length; i++)

Then change the function write_headers_to_excel() to function write_headers_to_excel(table). Then change var myTableHead = document.getElementById('headers'); to var myTableHead = table.getElementsByTagName('thead')[0];. Same with your write_bodies_to_excel() or however you want to set that up.

White spaces are required between publicId and systemId

If you're working from some network that requires you to use a proxy in your browser to connect to the internet (likely an office building), that might be it. I had the same issue and adding the proxy configs to the network settings solved it.

  • Go to your preferences (Eclipse -> Preferences on a Mac, or Window -> Preferences on a Windows)
  • Then -> General -> expand to view the list underneath -> Select Network Connections (don't expand)
  • At the top of the page that appears there is a drop down, select "Manual."
  • Then select "HTTP" in the list directly below the drop down (which now should have all it's options checked) and then click the "Edit" button to the right of the list.
  • Enter in the proxy url and port you need to connect to the internet in your web browser normally.
  • Repeat for "HTTPS."

If you don't know the proxy url and port, talk to your network admin.

changing visibility using javascript

function loadpage (page_request, containerid)
  var loading = document.getElementById ( "loading" ) ;

  // when connecting to server
  if ( page_request.readyState == 1 ) = "visible" ;

  // when loaded successfully
  if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1))
      document.getElementById(containerid).innerHTML=page_request.responseText ; = "hidden" ;

Setting maxlength of textbox with JavaScript or jQuery

$('#yourTextBoxId').live('change keyup paste', function(){
    if ($('#yourTextBoxId').val().length > 11) {

I Used this along with vars and selectors caching for performance and that did the trick ..

Get child Node of another Node, given node name

Check if the Node is a Dom Element, cast, and call getElementsByTagName()

Node doc = docs.item(i);
if(doc instanceof Element) {
    Element docElement = (Element)doc;
    cell = doc.getElementsByTagName("aoo").item(0);

changing source on html5 video tag

Using JavaScript and jQuery:

<script src="js/jquery.js"></script>
<video id="vid" width="1280" height="720" src="v/myvideo01.mp4" controls autoplay></video>
function chVid(vid) {
<div onclick="chVid('v/myvideo02.mp4')">See my video #2!</div>

Add event handler for body.onload by javascript within <body> part

body.addEventListener("load", init(), false);

That init() is saying run this function now and assign whatever it returns to the load event.

What you want is to assign the reference to the function, not the result. So you need to drop the ().

body.addEventListener("load", init, false);

Also you should be using window.onload and not body.onload

addEventListener is supported in most browsers except IE 8.

Removing elements by class name?

const elem= document.getElementsByClassName('column')

for (let i = elem.length; 0 < i ; )


const elem= document.getElementsByClassName('column')

while (elem.length > 0 )

get all the elements of a particular form

If you only want form elements that have a name attribute, you can filter the form elements.

const form = document.querySelector("your-form")
Array.from(form.elements).filter(e => e.getAttribute("name"))

Getting an attribute value in xml element

How about:


import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;

public class Demo {

    public static void main(String[] args) throws Exception {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document document = db.parse(new File("input.xml"));
        NodeList nodeList = document.getElementsByTagName("Item");
        for(int x=0,size= nodeList.getLength(); x<size; x++) {

Add CSS to <head> with JavaScript?

Here's a simple way.

 * Add css to the document
 * @param {string} css
function addCssToDocument(css){
  var style = document.createElement('style')
  style.innerText = css

document.createElement("script") synchronously

Ironically, I have what you want, but want something closer to what you had.

I am loading things in dynamically and asynchronously, but with an load callback like so (using dojo and xmlhtpprequest)

    url: 'getCode.php',
    handleAs: "javascript",
    content : {
    module : 'my.js'
  load: function() {
  error: function(errorMessage) {

For a more detailed explanation, see here

The problem is that somewhere along the line the code gets evaled, and if there's anything wrong with your code, the console.error(errorMessage); statement will indicate the line where eval() is, not the actual error. This is SUCH a big problem that I am actually trying to convert back to <script> statements (see here.

Line Break in XML?

In XML a line break is a normal character. You can do this:

  <text>some text
three lines</text>

and the contents of <text> will be

some text
three lines

If this does not work for you, you are doing something wrong. Special "workarounds" like encoding the line break are unnecessary. Stuff like \n won't work, on the other hand, because XML has no escape sequences*.

* Note that &#xA; is the character entity that represents a line break in serialized XML. "XML has no escape sequences" means the situation when you interact with a DOM document, setting node values through the DOM API.

This is where neither &#xA; nor things like \n will work, but an actual newline character will. How this character ends up in the serialized document (i.e. "file") is up to the API and should not concern you.

Since you seem to wonder where your line breaks go in HTML: Take a look into your source code, there they are. HTML ignores line breaks in source code. Use <br> tags to force line breaks on screen.

Here is a JavaScript function that inserts <br> into a multi-line string:

function nl2br(s) { return s.split(/\r?\n/).join("<br>"); }

Alternatively you can force line breaks at new line characters with CSS:

div.lines {
    white-space: pre-line;

alert a variable value

show alert box with use variable with message

$(document).ready(function() {
var total = 30 ;
alert("your total is :"+ total +"rs");

Executing <script> elements inserted with .innerHTML

Thanks to Larry's script, which worked perfectly well in IE10, this is what I've used:

$('#' + id)[0].innerHTML = result;
$('#' + id + " script").each(function() { this.text = this.text || $(this).text();} );

How do I get the web page contents from a WebView?

This is an answer based on jluckyiv's, but I think it is better and simpler to change Javascript as follows.


Adding an onclick event to a table row

function selectRowToInput(){
var table = document.getElementById("table");
var rows = table.getElementsByTagName("tr");
for (var i = 0; i < rows.length; i++)
    var currentRow = table.rows[i];
    currentRow.onclick = function() {



Javascript - How to detect if document has loaded (IE 7/Firefox 3)

I have other solution, my application need to be started when new object of MyApp is created, so it looks like:

function MyApp(objId){
          if(!document || !document.body || !window[objId]){
//and i am starting it 
var app=new MyApp('app');

it is working on all browsers, that i know.

Read XML Attribute using XmlDocument

XmlDocument.Attributes perhaps? (Which has a method GetNamedItem that will presumably do what you want, although I've always just iterated the attribute collection)

Detecting when Iframe content has loaded (Cross browser)

to detect when the iframe has loaded and its document is ready?

It's ideal if you can get the iframe to tell you itself from a script inside the frame. For example it could call a parent function directly to tell it it's ready. Care is always required with cross-frame code execution as things can happen in an order you don't expect. Another alternative is to set ‘var isready= true;’ in its own scope, and have the parent script sniff for ‘contentWindow.isready’ (and add the onload handler if not).

If for some reason it's not practical to have the iframe document co-operate, you've got the traditional load-race problem, namely that even if the elements are right next to each other:

<img id="x" ... />
<script type="text/javascript">
    document.getElementById('x').onload= function() {

there is no guarantee that the item won't already have loaded by the time the script executes.

The ways out of load-races are:

  1. on IE, you can use the ‘readyState’ property to see if something's already loaded;

  2. if having the item available only with JavaScript enabled is acceptable, you can create it dynamically, setting the ‘onload’ event function before setting source and appending to the page. In this case it cannot be loaded before the callback is set;

  3. the old-school way of including it in the markup:

    <img onload="callback(this)" ... />

Inline ‘onsomething’ handlers in HTML are almost always the wrong thing and to be avoided, but in this case sometimes it's the least bad option.

JavaScript closure inside loops – simple practical example

Just change the var keyword to let.

var is function scoped.

let is block scoped.

When you start you code the for loop will iterate and assign the value of i to 3, which will remain 3 throughout your code. I suggest you to read more about scopes in node (let,var,const and others)

funcs = [];
for (let i = 0; i < 3; i++) {      // let's create 3 functions
  funcs[i] =async function() {          // and store them in funcs
    await console.log("My value: " + i); // each should log its value.
for (var j = 0; j < 3; j++) {
  funcs[j]();                      // and now let's run each one to see

How to tell if a <script> tag failed to load

onerror Event

*Update August 2017: onerror is fired by Chrome and Firefox. onload is fired by Internet Explorer. Edge fires neither onerror nor onload. I wouldnt use this method but it could work in some cases. See also

<link> onerror do not work in IE


Definition and Usage The onerror event is triggered if an error occurs while loading an external file (e.g. a document or an image).

Tip: When used on audio/video media, related events that occurs when there is some kind of disturbance to the media loading process, are:

  • onabort
  • onemptied
  • onstalled
  • onsuspend


element onerror="myScript">

In JavaScript, using the addEventListener() method:

object.addEventListener("error", myScript);

Note: The addEventListener() method is not supported in Internet Explorer 8 and earlier versions.

Example Execute a JavaScript if an error occurs when loading an image:

img src="image.gif" onerror="myFunction()">

How may I reference the script tag that loaded the currently-executing script?

I was inserting script tags dynamically with this usual alternative to eval and simply set a global property currentComponentScript right before adding to the DOM.

  const old = el.querySelector("script")[0];
  const replacement = document.createElement("script");
  replacement.setAttribute("type", "module");
  window.currentComponentScript = replacement;

Doesn't work in a loop though. The DOM doesn't run the scripts until the next macrotask so a batch of them will only see the last value set. You'd have to setTimeout the whole paragraph, and then setTimeout the next one after the previous finishes. I.e. chain the setTimeouts, not just call setTimeout multiple times in a row from a loop.

Get Element value with minidom with Python

I know this question is pretty old now, but I thought you might have an easier time with ElementTree

from xml.etree import ElementTree as ET
import datetime

f = ET.XML(data)

for element in f:
    if element.tag == "currentTime":
        # Handle time data was pulled
        currentTime = datetime.datetime.strptime(element.text, "%Y-%m-%d %H:%M:%S")
    if element.tag == "cachedUntil":
        # Handle time until next allowed update
        cachedUntil = datetime.datetime.strptime(element.text, "%Y-%m-%d %H:%M:%S")
    if element.tag == "result":
        # Process list of skills

I know that's not super specific, but I just discovered it, and so far it's a lot easier to get my head around than the minidom (since so many nodes are essentially white space).

For instance, you have the tag name and the actual text together, just as you'd probably expect:

>>> element[0]
<Element currentTime at 40984d0>
>>> element[0].tag
>>> element[0].text
'2010-04-12 02:45:45'e

What's the best way to loop through a set of elements in JavaScript?

I know this question is old -- but here's another, extremely simple solution ...

var elements = Array.from(document.querySelectorAll("div"));

Then it can be used like any, standard array.

How to inject Javascript in WebBrowser control?

If all you really want is to run javascript, this would be easiest (VB .Net):

MyWebBrowser.Navigate("javascript:function foo(){alert('hello');}foo();")

I guess that this wouldn't "inject" it but it'll run your function, if that's what you're after. (Just in case you've over-complicated the problem.) And if you can figure out how to inject in javascript, put that into the body of the function "foo" and let the javascript do the injection for you.

PDO closing connection

I created a derived class to have a more self-documented instruction instead of $conn=null;.

class CMyPDO extends PDO {
    public function __construct($dsn, $username = null, $password = null, array $options = null) {
        parent::__construct($dsn, $username, $password, $options);

    static function getNewConnection() {
        try {
            $conn = new CMyPDO("mysql:host=$host;dbname=$dbname",$user,$pass);
        catch (PDOException $exc) {
            echo $exc->getMessage();
        return $conn;

    static function closeConnection(&$conn) {

So I can call my code between:

// my code

Is there an alternative to string.Replace that is case-insensitive?

The regular expression method should work. However what you can also do is lower case the string from the database, lower case the %variables% you have, and then locate the positions and lengths in the lower cased string from the database. Remember, positions in a string don't change just because its lower cased.

Then using a loop that goes in reverse (its easier, if you do not you will have to keep a running count of where later points move to) remove from your non-lower cased string from the database the %variables% by their position and length and insert the replacement values.

Retrieve Button value with jQuery

As a button value is an attribute you need to use the .attr() method in jquery. This should do it

<script type="text/javascript">
    $(document).ready(function() {
        $('.my_button').click(function() {

You can also use attr to set attributes, more info in the docs.

This only works in JQuery 1.6+. See postpostmodern's answer for older versions.

Get the Id of current table row with Jquery

First, your jQuery will not work at all unless you enclose all your trs and tds in a table:


Second, your code gets the id of the first tr of the page, since you select all the trs of the page and get the id of the first one (.attr() returns the attribute of the first element in the set of elements it is used on)

Your current code:

  $('input[type=button]' ).click(function() {
   bid = ( ; // button ID 
   trid = $('tr').attr('id'); // ID of the the first TR on the page
                              // $('tr') selects all trs in the DOM

trid is always TEST1 (jsFiddle)

Instead of selecting all trs on the page with $('tr'), you want to select the first ancestor of the clicked upon input that is a tr. Use .closest() for this in the form $(this).closest('tr').

You can reference the clicked on element as this, make a jQuery object out of it with the form $(this), so you have access to all the jQuery methods on it.

What your code should look like:

  // On DOM ready...
$(function() {

      $('input[type=button]' ).click(function() {

          var bid, trid; // Declare variables. If you don't use var 
                         // you will bind bid and trid 
                         // to the window, since you make them global variables.

          bid = ( ; // button ID 

          trid = $(this).closest('tr').attr('id'); // table row ID 

jsFiddle example

Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?

I solved this by writing the explicit IP address defined in the Listener.ora file as the hostname.

enter image description here

So, instead of "localhost", I wrote "" as the "Hostname" in the SQL Developer field.

In the below picture I highlighted the input boxes that I've modified: enter image description here Invalid hostname for server: local

I had this issue in my android app when grabbing an xml file the format of my link was not valid, I reformatted with the full url and it worked.

How to get an absolute file path in Python

This always gets the right filename of the current script, even when it is called from within another script. It is especially useful when using subprocess.

import sys,os

filename = sys.argv[0]

from there, you can get the script's full path with:

>>> os.path.abspath(filename)

It also makes easier to navigate folders by just appending /.. as many times as you want to go 'up' in the directories' hierarchy.

To get the cwd:

>>> os.path.abspath(filename+"/..")

For the parent path:

>>> os.path.abspath(filename+"/../..")

By combining "/.." with other filenames, you can access any file in the system.

Purpose of ESI & EDI registers?

In addition to the string operations (MOVS/INS/STOS/CMPS/SCASB/W/D/Q etc.) mentioned in the other answers, I wanted to add that there are also more "modern" x86 assembly instructions that implicitly use at least EDI/RDI:

The SSE2 MASKMOVDQU (and the upcoming AVX VMASKMOVDQU) instruction selectively write bytes from an XMM register to memory pointed to by EDI/RDI.

How to get a index value from foreach loop in jstl

This works for me:

<c:forEach var="i" begin="1970" end="2000">
    <option value="${2000-(i-1970)}">${2000-(i-1970)} 

How to check for DLL dependency?

The safest thing is have some clean virtual machine, on which you can test your program. On every version you'd like to test, restore the VM to its initial clean value. Then install your program using its setup, and see if it works.

Dll problems have different faces. If you use Visual Studio and dynamically link to the CRT, you have to distribute the CRT DLLs. Update your VS, and you have to distribute another version of the CRT. Just checking dependencies is not enough, as you might miss those. Doing a full install on a clean machine is the only safe solution, IMO.

If you don't want to setup a full-blown test environment and have Windows 7, you can use XP-Mode as the initial clean machine, and XP-More to duplicate the VM.

Specify multiple attribute selectors in CSS

[class*="test"],[class="second"] {
background: #ffff00;

How to enable explicit_defaults_for_timestamp?

I'm Using Windows 8.1 and I use this command


instead of


and it works fine..

What is the meaning of the prefix N in T-SQL statements and when should I use it?

Let me tell you an annoying thing that happened with the N' prefix - I wasn't able to fix it for two days.

My database collation is SQL_Latin1_General_CP1_CI_AS.

It has a table with a column called MyCol1. It is an Nvarchar

This query fails to match Exact Value That Exists.

SELECT TOP 1 * FROM myTable1 WHERE  MyCol1 = 'ESKI'  

// 0 result

using prefix N'' fixes it

SELECT TOP 1 * FROM myTable1 WHERE  MyCol1 = N'ESKI'  

// 1 result - found!!!!

Why? Because latin1_general doesn't have big dotted I that's why it fails I suppose.

Load content of a div on another page

You just need to add a jquery selector after the url.


Example straight from the API:

$('#result').load('ajax/test.html #container');

So what that does is it loads the #container element from the specified url.

Random number between 0 and 1 in python


From the docs for the Python random module:

Functions for integers:

random.randrange(start, stop[, step])

    Return a randomly selected element from range(start, stop, step).
    This is equivalent to choice(range(start, stop, step)), but doesn’t
    actually build a range object.

That explains why it only gives you 0, doesn't it. range(0,1) is [0]. It is choosing from a list consisting of only that value.

Also from those docs:

    Return the next random floating point number in the range [0.0, 1.0).

But if your inclusion of the numpy tag is intentional, you can generate many random floats in that range with one call using a np.random function.

Regex pattern inside SQL Replace function?

I stumbled across this post looking for something else but thought I'd mention a solution I use which is far more efficient - and really should be the default implementation of any function when used with a set based query - which is to use a cross applied table function. Seems the topic is still active so hopefully this is useful to someone.

Example runtime on a few of the answers so far based on running recursive set based queries or scalar function, based on 1m rows test set removing the chars from a random newid, ranges from 34s to 2m05s for the WHILE loop examples and from 1m3s to {forever} for the function examples.

Using a table function with cross apply achieves the same goal in 10s. You may need to adjust it to suit your needs such as the max length it handles.


CREATE FUNCTION [dbo].[RemoveChars](@InputUnit VARCHAR(40))
        WITH Numbers_prep(Number) AS
        ,Numbers(Number) AS
                SELECT TOP (ISNULL(LEN(@InputUnit),0))
                    row_number() OVER (ORDER BY (SELECT NULL))
                FROM Numbers_prep a
                    CROSS JOIN Numbers_prep b
                FROM  Numbers
                WHERE substring(@InputUnit,Number,1) like '%[0-9]%'
                ORDER BY Number
                FOR XML PATH('')
            ) Sub(OutputUnit)


SET column = o.OutputUnit
FROM ##t t
CROSS APPLY [dbo].[RemoveChars](t.column) o

apt-get for Cygwin?

You can use Chocolatey to install cyg-get and then install your packages with it.

For example:

choco install cyg-get


cyg-get install my-package

Explicitly select items from a list or tuple

like often when you have a boolean numpy array like mask

[mylist[i] for i in np.arange(len(mask), dtype=int)[mask]]

A lambda that works for any sequence or np.array:

subseq = lambda myseq, mask : [myseq[i] for i in np.arange(len(mask), dtype=int)[mask]]

newseq = subseq(myseq, mask)

Check if option is selected with jQuery, if not select a default

I was just looking for something similar and found this:

$('.mySelect:not(:has(option[selected])) option[value="2"]').attr('selected', true);

This finds all select menus in the class that don't already have an option selected, and selects the default option ("2" in this case).

I tried using :selected instead of [selected], but that didn't work because something is always selected, even if nothing has the attribute

Unit testing with Spring Security

I asked the same question myself over here, and just posted an answer that I recently found. Short answer is: inject a SecurityContext, and refer to SecurityContextHolder only in your Spring config to obtain the SecurityContext

Pass Model To Controller using Jquery/Ajax

Looks like your IndexPartial action method has an argument which is a complex object. If you are passing a a lot of data (complex object), It might be a good idea to convert your action method to a HttpPost action method and use jQuery post to post data to that. GET has limitation on the query string value.

public PartialViewResult IndexPartial(DashboardViewModel m)
   //May be you want to pass the posted model to the parial view?
   return PartialView("_IndexPartial");

Your script should be

var url = "@Url.Action("IndexPartial","YourControllerName")";

var model = { Name :"Shyju", Location:"Detroit"};

$.post(url, model, function(res){
   //res contains the markup returned by the partial view
   //You probably want to set that to some Div.

Assuming Name and Location are properties of your DashboardViewModel class and SomeDivToShowTheResult is the id of a div in your page where you want to load the content coming from the partialview.

Sending complex objects?

You can build more complex object in js if you want. Model binding will work as long as your structure matches with the viewmodel class

var model = { Name :"Shyju", 
              Interests : ["Code","Coffee","Stackoverflow"]

    type: "POST",
    data: JSON.stringify(model),
    url: url,
    contentType: "application/json"
}).done(function (res) {

For the above js model to be transformed to your method parameter, Your View Model should be like this.

public class DashboardViewModel
  public string Name {set;get;}
  public string Location {set;get;}
  public List<string> Interests {set;get;}

And in your action method, specify [FromBody]

public PartialViewResult IndexPartial([FromBody] DashboardViewModel m)
    return PartialView("_IndexPartial",m);

Best way to parseDouble with comma as decimal separator?

Double.parseDouble(p.replace(',','.')) very quick as it searches the underlying character array on a char-by-char basis. The string replace versions compile a RegEx to evaluate.

Basically replace(char,char) is about 10 times quicker and since you'll be doing these kind of things in low-level code it makes sense to think about this. The Hot Spot optimiser will not figure it out... Certainly doesn't on my system.

Why is there no ForEach extension method on IEnumerable?

You could write this extension method:

// Possibly call this "Do"
IEnumerable<T> Apply<T> (this IEnumerable<T> source, Action<T> action)
    foreach (var e in source)
        yield return e;


Allows chaining:



It won't actually do anything until you do something to force iteration. For that reason, it shouldn't be called .ForEach(). You could write .ToList() at the end, or you could write this extension method, too:

// possibly call this "Realize"
IEnumerable<T> Done<T> (this IEnumerable<T> source)
    foreach (var e in source)
        // do nothing

    return source;

This may be too significant a departure from the shipping C# libraries; readers who are not familiar with your extension methods won't know what to make of your code.

Allowing Untrusted SSL Certificates with HttpClient

With Windows 8.1, you can now trust invalid SSL certs. You have to either use the Windows.Web.HttpClient or if you want to use the System.Net.Http.HttpClient, you can use the message handler adapter I wrote:

Docs are on the GitHub:

Send Message in C#

You don't need to send messages.

Add an event to the one form and an event handler to the other. Then you can use a third project which references the other two to attach the event handler to the event. The two DLLs don't need to reference each other for this to work.

JavaScript: Check if mouse button down?

Regarding Pax' solution: it doesn't work if user clicks more than one button intentionally or accidentally. Don't ask me how I know :-(.

The correct code should be like that:

var mouseDown = 0;
document.body.onmousedown = function() { 
document.body.onmouseup = function() {

With the test like this:

  // crikey! isn't she a beauty?

If you want to know what button is pressed, be prepared to make mouseDown an array of counters and count them separately for separate buttons:

// let's pretend that a mouse doesn't have more than 9 buttons
var mouseDown = [0, 0, 0, 0, 0, 0, 0, 0, 0],
    mouseDownCount = 0;
document.body.onmousedown = function(evt) { 
document.body.onmouseup = function(evt) {

Now you can check what buttons were pressed exactly:

  // alright, let's lift the little bugger up!
  for(var i = 0; i < mouseDown.length; ++i){
      // we found it right there!

Now be warned that the code above would work only for standard-compliant browsers that pass you a button number starting from 0 and up. IE uses a bit mask of currently pressed buttons:

  • 0 for "nothing is pressed"
  • 1 for left
  • 2 for right
  • 4 for middle
  • and any combination of above, e.g., 5 for left + middle

So adjust your code accordingly! I leave it as an exercise.

And remember: IE uses a global event object called … "event".

Incidentally IE has a feature useful in your case: when other browsers send "button" only for mouse button events (onclick, onmousedown, and onmouseup), IE sends it with onmousemove too. So you can start listening for onmousemove when you need to know the button state, and check for evt.button as soon as you got it — now you know what mouse buttons were pressed:

// for IE only!
document.body.onmousemove = function(){
    // aha! we caught a feisty little sheila!

Of course you get nothing if she plays dead and not moving.

Relevant links:

Update #1: I don't know why I carried over the document.body-style of code. It will be better to attach event handlers directly to the document.

How to store arrays in MySQL?

you can store your array using group_Concat like that

 INSERT into Table1 (fruits)  (SELECT GROUP_CONCAT(fruit_name) from table2)
 WHERE ..... //your clause here

HERE an example in fiddle

What is the best way to create a string array in python?

But what is a reason to use fixed size? There is no actual need in python to use fixed size arrays(lists) so you always have ability to increase it's size using append, extend or decrease using pop, or at least you can use slicing.

x = [''  for x in xrange(10)]

Why are the Level.FINE logging messages not showing?


As mentioned by @Sheepy, the reason why it doesn't work is that java.util.logging.Logger has a root logger that defaults to Level.INFO, and the ConsoleHandler attached to that root logger also defaults to Level.INFO. Therefore, in order to see the FINE (, FINER or FINEST) output, you need to set the default value of the root logger and its ConsoleHandler to Level.FINE as follows:


The problem of your Update (solution)

As mentioned by @mins, you will have the messages printed twice on the console for INFO and above: first by the anonymous logger, then by its parent, the root logger which also has a ConsoleHandler set to INFO by default. To disable the root logger, you need to add this line of code: logger.setUseParentHandlers(false);

There are other ways to prevent logs from being processed by default Console handler of the root logger mentioned by @Sheepy, e.g.:

Logger.getLogger("").getHandlers()[0].setLevel( Level.OFF );

But Logger.getLogger("").setLevel( Level.OFF ); won't work because it only blocks the message passed directly to the root logger, not the message comes from a child logger. To illustrate how the Logger Hierarchy works, I draw the following diagram:

enter image description here

public void setLevel(Level newLevel) set the log level specifying which message levels will be logged by this logger. Message levels lower than this value will be discarded. The level value Level.OFF can be used to turn off logging. If the new level is null, it means that this node should inherit its level from its nearest ancestor with a specific (non-null) level value.

How to read text file in JavaScript

(fiddle: )

  1. Usage


<textarea id='tbMain' ></textarea>
<a id='btnOpen' href='#' >Open</a>


document.getElementById('btnOpen').onclick = function(){
        document.getElementById('tbMain').value = txt; 
  1. Js Helper functions
function openFile(callBack){
  var element = document.createElement('input');
  element.setAttribute('type', "file");
  element.setAttribute('id', "btnOpenFile");
  element.onchange = function(){
      } = 'none';

function readText(filePath,callBack) {
    var reader;
    if (window.File && window.FileReader && window.FileList && window.Blob) {
        reader = new FileReader();
    } else {
        alert('The File APIs are not fully supported by your browser. Fallback required.');
        return false;
    var output = ""; //placeholder for text output
    if(filePath.files && filePath.files[0]) {           
        reader.onload = function (e) {
            output =;
        };//end onload()
    }//end if html5 filelist support
    else { //this is where you could fallback to Java Applet, Flash or similar
        return false;
    return true;

API pagination best practices

I think currently your api's actually responding the way it should. The first 100 records on the page in the overall order of objects you are maintaining. Your explanation tells that you are using some kind of ordering ids to define the order of your objects for pagination.

Now, in case you want that page 2 should always start from 101 and end at 200, then you must make the number of entries on the page as variable, since they are subject to deletion.

You should do something like the below pseudocode:

page_max = 100
def get_page_results(page_no) :

    start = (page_no - 1) * page_max + 1
    end = page_no * page_max

    return fetch_results_by_id_between(start, end)

Datetime current year and month in Python

You can always use a sub-string method:

import datetime;

today = str(;
curr_year = int(today[:4]);
curr_month = int(today[5:7]);

This will get you the current month and year in integer format. If you want them to be strings you simply have to remove the " int " precedence while assigning values to the variables curr_year and curr_month.

Adding ID's to google map markers

Why not use an cache that stores each marker object and references an ID?

var markerCache= {};
var idGen= 0;

function codeAddress(addr, contentStr){
    // create marker
    // store
    markerCache[idGen++]= marker;

Edit: of course this relies on a numeric index system that doesn't offer a length property like an array. You could of course prototype the Object object and create a length, etc for just such a thing. OTOH, generating a unique ID value (MD5, etc) of each address might be the way to go.

How to adjust the size of y axis labels only in R?

As the title suggests that we want to adjust the size of the labels and not the tick marks I figured that I actually might add something to the question, you need to use the mtext() if you want to specify one of the label sizes, or you can just use par(cex.lab=2) as a simple alternative. Here's a more advanced mtext() example:

foo <- data.frame(X = rnorm(10), Y = rnorm(10))
plot(Y ~ X, data=foo,
     yaxt="n", ylab="", 
     xlab="Regular boring x", 
mtext("Awesome Y variable", side=2, line=2.2, cex=2)

enter image description here

You may need to adjust the line= option to get the optimal positioning of the text but apart from that it's really easy to use.

Datatables warning(table id = 'example'): cannot reinitialise data table

You can add destroy:true to the configuration to make sure data table already present is removed before being reinitialized.

    destroy: true,

How to get base64 encoded data from html image

You can try following sample

<img id="preview" src="">
<canvas id="myCanvas" />

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
var img = document.getElementById("preview");
ctx.drawImage(img, 10, 10);

Javascript change color of text and background to input value

document.getElementById("fname").style.borderTopColor = 'red';
document.getElementById("fname").style.borderBottomColor = 'red';

Run .php file in Windows Command Prompt (cmd)

you can for example: set your environment variable path with php.exe folder e.g c:\program files\php

create a script file in d:\ with filename as a.php

open cmd: go to d: drive using d: command

type following command

php -f a.php

you will see the output

Difference between window.location.href=window.location.href and window.location.reload()

Came across this question researching some aberrant behavior in IE, specifically IE9, didn't check older versions. It seems


results in a refresh that blanks out the entire screen for a second, where as

 window.location = document.URL;

refreshes the page much more quickly, almost imperceptibly.

Doing a bit more research, and some experimentation with fiddler, it seems that window.location.reload() will bypass the cache and reload from the server regardless if you pass the boolean with it or not, this includes getting all of your assets (images, scripts, style sheets, etc) again. So if you just want the page to refresh the HTML, the window.location = document.URL will return much quicker and with less traffic.

A difference in behavior between browsers is that when IE9 uses the reload method it clears the visible page and seemingly rebuilds it from scratch, where FF and chrome wait till they get the new assets and rebuild them if they are different.

Display array values in PHP

a simple code snippet that i prepared, hope it will be usefull for you;

$ages = array("Kerem"=>"35","Ahmet"=>"65","Talip"=>"62","Kamil"=>"60");


for ($i=0; $i < count($ages); $i++){
echo "Key : " . key($ages) . " Value : " . current($ages) . "<br>";

How do I detect a click outside an element?

const button = document.querySelector('button')_x000D_
const box = document.querySelector('.box');_x000D_
const toggle = event => {_x000D_
  if (!'.box')) {_x000D_
    console.log('Click outside');_x000D_
      ? document.addEventListener('click', toggle)_x000D_
      : document.removeEventListener('click', toggle);_x000D_
  } else {_x000D_
    console.log('Click inside');_x000D_
button.addEventListener('click', toggle);
.box {_x000D_
  position: absolute;_x000D_
  display: none;_x000D_
  margin-top: 8px;_x000D_
  padding: 20px;_x000D_
  background: lightgray;_x000D_
_x000D_ {_x000D_
  display: block;_x000D_
<button>Toggle box</button>_x000D_
<div class="box">_x000D_
  <form action="">_x000D_
    <input type="text">_x000D_
    <button type="button">Search</button>_x000D_

Having issues with a MySQL Join that needs to meet multiple conditions

If you join the facilities table twice you will get what you are after:

select u.* 
from room u 
  JOIN facilities_r fu1 on fu1.id_uc = u.id_uc and fu1.id_fu = '4'
  JOIN facilities_r fu2 on fu2.id_uc = u.id_uc and fu2.id_fu = '3' 
where 1 and vizibility='1' 
group by id_uc 
order by u_premium desc, id_uc desc

Python - PIP install trouble shooting - PermissionError: [WinError 5] Access is denied

Do not use the command prompt in the IDE. Run the command prompt from windows as an administrator. I'm sure this will solve the problem. If not, uninstall pip and reinstall the latest one directly.

How to Lock/Unlock screen programmatically?


As some folks needs help in Unlocking device after locking programmatically, I came through post Android screen lock/ unlock programatically, please have look, may help you.

Original Answer was:

You need to get Admin permission and you can lock phone screen

please check below simple tutorial to achive this one

Lock Phone Screen Programmtically

also here is the code example..

public class LockScreenActivity extends Activity implements OnClickListener {  
 private Button lock;  
 private Button disable;  
 private Button enable;  
 static final int RESULT_ENABLE = 1;  

     DevicePolicyManager deviceManger;  
     ActivityManager activityManager;  
     ComponentName compName;  

    public void onCreate(Bundle savedInstanceState) {  

        deviceManger = (DevicePolicyManager)getSystemService(  
        activityManager = (ActivityManager)getSystemService(  
        compName = new ComponentName(this, MyAdmin.class);  


        lock =(Button)findViewById(;  

        disable = (Button)findViewById(;  
        enable =(Button)findViewById(;  

 public void onClick(View v) {  

  if(v == lock){  
    boolean active = deviceManger.isAdminActive(compName);  
             if (active) {  

  if(v == enable){  
   Intent intent = new Intent(DevicePolicyManager  
                    "Additional text explaining why this needs to be added.");  
            startActivityForResult(intent, RESULT_ENABLE);  

  if(v == disable){  

 private void updateButtonStates() {  

        boolean active = deviceManger.isAdminActive(compName);  
        if (active) {  

        } else {  

  protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
         switch (requestCode) {  
             case RESULT_ENABLE:  
                 if (resultCode == Activity.RESULT_OK) {  
                     Log.i("DeviceAdminSample", "Admin enabled!");  
                 } else {  
                     Log.i("DeviceAdminSample", "Admin enable FAILED!");  
         super.onActivityResult(requestCode, resultCode, data);  

public class MyAdmin extends DeviceAdminReceiver{  

    static SharedPreferences getSamplePreferences(Context context) {  
        return context.getSharedPreferences(  
          DeviceAdminReceiver.class.getName(), 0);  

    static String PREF_PASSWORD_QUALITY = "password_quality";  
    static String PREF_PASSWORD_LENGTH = "password_length";  
    static String PREF_MAX_FAILED_PW = "max_failed_pw";  

    void showToast(Context context, CharSequence msg) {  
        Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();  

    public void onEnabled(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: enabled");  

    public CharSequence onDisableRequested(Context context, Intent intent) {  
        return "This is an optional message to warn the user about disabling.";  

    public void onDisabled(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: disabled");  

    public void onPasswordChanged(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw changed");  

    public void onPasswordFailed(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw failed");  

    public void onPasswordSucceeded(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw succeeded");  


What is the meaning of {...this.props} in Reactjs

It will compile to this:

React.createElement('div', this.props, 'Content Here');

As you can see above, it passes all it's props to the div.

Importing class/java files in Eclipse

create a new java project in Eclipse and copy .java files to its src directory, if you don't know where those source files should be placed, right click on the root of the project and choose new->class to create a test class and see where its .java file is placed, then put other files with it, in the same directory, you may have to adjust the package in those source files according to the new project directory structure.

if you use external libraries in your code, you have two options: either copy / download jar files or use maven if you use maven you'll have to create the project at maven project in the first place, creating java projects as maven projects are the way to go anyway but that's for another post...

Delete a database in phpMyAdmin


  1. Go to phpmyadmin home page.
  2. Click on 'Databases'.
  3. Select the database you want to delete. (put check mark)
  4. Click Drop.

changing minDate option in JQuery DatePicker not working

Use minDate as string:

$('#datePickerId').datepicker({minDate: '0'});

This would set today as minimum selectable date .

Delete many rows from a table using id in Mysql

how about using IN

WHERE ID IN (1,2) -- add as many ID as you want.

What is the difference between declarations, providers, and import in NgModule?

Adding a quick cheat sheet that may help after the long break with Angular:



declarations: [AppComponent]

What can we inject here? Components, pipes, directives



imports: [BrowserModule, AppRoutingModule]

What can we inject here? other modules



providers: [UserService]

What can we inject here? services



bootstrap: [AppComponent]

What can we inject here? the main component that will be generated by this module (top parent node for a component tree)



entryComponents: [PopupComponent]

What can we inject here? dynamically generated components (for instance by using ViewContainerRef.createComponent())



export: [TextDirective, PopupComponent, BrowserModule]

What can we inject here? components, directives, modules or pipes that we would like to have access to them in another module (after importing this module)

set div height using jquery (stretch div height)

well you can do this:


    var $header = $('#header');
    var $footer = $('#footer');
    var $content = $('#content');
    var $window = $(window).on('resize', function(){
       var height = $(this).height() - $header.height() + $footer.height();
    }).trigger('resize'); //on page load


see fiddle here:

Change URL without refresh the page


Based on Manipulating the browser history, passing the empty string as second parameter of pushState method (aka title) should be safe against future changes to the method, so it's better to use pushState like this:

history.pushState(null, '', '/en/step2');    

You can read more about that in mentioned article

Original Answer

Use history.pushState like this:

history.pushState(null, null, '/en/step2');

Update 2 to answer Idan Dagan's comment:

Why not using history.replaceState()?

From MDN

history.replaceState() operates exactly like history.pushState() except that replaceState() modifies the current history entry instead of creating a new one

That means if you use replaceState, yes the url will be changed but user can not use Browser's Back button to back to prev. state(s) anymore (because replaceState doesn't add new entry to history) and it's not recommended and provide bad UX.

Update 3 to add window.onpopstate

So, as this answer got your attention, here is additional info about manipulating the browser history, after using pushState, you can detect the back/forward button navigation by using window.onpopstate like this:

window.onpopstate = function(e) {
    // ... 

As the first argument of pushState is an object, if you passed an object instead of null, you can access that object in onpopstate which is very handy, here is how:

window.onpopstate = function(e) {
    if(e.state) {

Update 4 to add Reading the current state:

When your page loads, it might have a non-null state object, you can read the state of the current history entry without waiting for a popstate event using the history.state property like this:


Bonus: Use following to check history.pushState support:

if (history.pushState) {
  // \o/

Detect if a NumPy array contains at least one non-numeric value?

With numpy 1.3 or svn you can do this

In [1]: a = arange(10000.).reshape(100,100)

In [3]: isnan(a.max())
Out[3]: False

In [4]: a[50,50] = nan

In [5]: isnan(a.max())
Out[5]: True

In [6]: timeit isnan(a.max())
10000 loops, best of 3: 66.3 µs per loop

The treatment of nans in comparisons was not consistent in earlier versions.

Can I have multiple :before pseudo-elements for the same element?

I've resolved this using:

.element:before {
    font-family: "Font Awesome 5 Free" , "CircularStd";
    content: "\f017" " Date";

Using the font family "font awesome 5 free" for the icon, and after, We have to specify the font that we are using again because if we doesn't do this, navigator will use the default font (times new roman or something like this).

CodeIgniter: "Unable to load the requested class"

I had a similar issue when deploying from OSx on my local to my Linux live site.

It ran fine on OSx, but on Linux I was getting:

An Error Was Encountered

Unable to load the requested class: Ckeditor

The problem was that Linux paths are apparently case-sensitive so I had to rename my library files from "ckeditor.php" to "CKEditor.php".

I also changed my load call to match the capitalization:


How to make an element width: 100% minus padding?

You can do this:

width: auto;
padding: 20px;

get selected value in datePicker and format it

Use jquery-dateFormat. It will solve your problem.

You need to include the jquery.dateFormat in your html file.

var date = $('#scheduleDate').val();
document.write($, "dd,MM,yyyy"));

var dateTypeVar = $('#scheduleDate').datepicker('getDate');
document.write($, "dd-MM-yy"));

The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

You may get your answer here: Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)


It might be due to various issues.I cant say which one is there in your case. It may be because:

  • DCOM is not enabled in host pc or target pc or on both
  • your firewall or even your antivirus is preventing the access
  • any WMI related service is disabled

Some WMI related services are:

  • Remote Access Auto Connection Manager
  • Remote Access Connection Manager
  • Remote Procedure Call (RPC)
  • Remote Procedure Call (RPC) Locator
  • Remote Registry

For DCOM settings refer to registry key HKLM\Software\Microsoft\OLE, value EnableDCOM. The value should be set to 'Y'.

Edit a text file on the console using Powershell

You can do the following:

bash -c "nano index.html"

The command above opens the index.html file with the nano editor within Powershell.

Alternatively, you can use the vim editor with the following command

bash -c "vi index.html"

How to add a reference programmatically

Browsing the registry for guids or using paths, which method is best. If browsing the registry is no longer necessary, won't it be the better way to use guids? Office is not always installed in the same directory. The installation path can be manually altered. Also the version number is a part of the path. I could have never predicted that Microsoft would ever add '(x86)' to 'Program Files' before the introduction of 64 bits processors. If possible I would try to avoid using a path.

The code below is derived from Siddharth Rout's answer, with an additional function to list all the references that are used in the active workbook. What if I open my workbook in a later version of Excel? Will the workbook still work without adapting the VBA code? I have already checked that the guids for office 2003 and 2010 are identical. Let's hope that Microsoft doesn't change guids in future versions.

The arguments 0,0 (from .AddFromGuid) should use the latest version of a reference (which I have not been able to test).

What are your thoughts? Of course we cannot predict the future but what can we do to make our code version proof?

Sub AddReferences(wbk As Workbook)
    ' Run DebugPrintExistingRefs in the immediate pane, to show guids of existing references
    AddRef wbk, "{00025E01-0000-0000-C000-000000000046}", "DAO"
    AddRef wbk, "{00020905-0000-0000-C000-000000000046}", "Word"
    AddRef wbk, "{91493440-5A91-11CF-8700-00AA0060263B}", "PowerPoint"
End Sub

Sub AddRef(wbk As Workbook, sGuid As String, sRefName As String)
    Dim i As Integer
    On Error GoTo EH
    With wbk.VBProject.References
        For i = 1 To .Count
            If .Item(i).Name = sRefName Then
               Exit For
            End If
        Next i
        If i > .Count Then
           .AddFromGuid sGuid, 0, 0 ' 0,0 should pick the latest version installed on the computer
        End If
    End With
EX: Exit Sub
EH: MsgBox "Error in 'AddRef'" & vbCrLf & vbCrLf & err.Description
    Resume EX
    Resume ' debug code
End Sub

Public Sub DebugPrintExistingRefs()
    Dim i As Integer
    With Application.ThisWorkbook.VBProject.References
        For i = 1 To .Count
            Debug.Print "    AddRef wbk, """ & .Item(i).GUID & """, """ & .Item(i).Name & """"
        Next i
    End With
End Sub

The code above does not need the reference to the "Microsoft Visual Basic for Applications Extensibility" object anymore.

Create HTML table using Javascript

In the html file there are three input boxes with userid,username,department respectively.

These inputboxes are used to get the input from the user.

The user can add any number of inputs to the page.

When clicking the button the script will enable the debugger mode.

In javascript, to enable the debugger mode, we have to add the following tag in the javascript.


    Tools->Internet Options-->Advanced-->uncheck
    Disable script debugging(Internet Explorer)
    Disable script debugging(Other)

    <html xmlns="" >

    <head runat="server">

    <title>Dynamic Table</title>

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

    // <!CDATA[

    function CmdAdd_onclick() {

    var newTable,startTag,endTag;

    //Creating a new table

    startTag="<TABLE id='mainTable'><TBODY><TR><TD style=\"WIDTH: 120px\">User ID</TD>
    <TD style=\"WIDTH: 120px\">User Name</TD><TD style=\"WIDTH: 120px\">Department</TD></TR>"



    var trContents;

    //Get the row contents








    // Add previous rows







    //Add the Latest row

    newTable+="<TR><TD style=\"WIDTH: 120px\" >" +
        document.getElementById('userid').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('username').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('department').value +"</TD><TR>";


    //Update the Previous Table With New Table.



    // ]]>




    <form id="form1" runat="server">


    <br />


    <input id="userid" type="text" /><br />


    <input id="username" type="text" /><br />


    <input id="department" type="text" />


    <input id="CmdAdd" type="button" value="Add" onclick="return CmdAdd_onclick()" />


    <div id="tableDiv" style="text-align:center" >

    <table id="mainTable">

    <tr style="width:120px " >

    <td >User ID</td>

    <td>User Name</td>








Comparing two joda DateTime instances

This code (example) :

    Chronology ch1 = GregorianChronology.getInstance();     Chronology ch2 = ISOChronology.getInstance();      DateTime dt = new DateTime("2013-12-31T22:59:21+01:00",ch1);     DateTime dt2 = new DateTime("2013-12-31T22:59:21+01:00",ch2);      System.out.println(dt);     System.out.println(dt2);      boolean b = dt.equals(dt2);      System.out.println(b); 

Will print :

2013-12-31T16:59:21.000-05:00 2013-12-31T16:59:21.000-05:00 false 

You are probably comparing two DateTimes with same date but different Chronology.

Override intranet compatibility mode IE8

I found a working answer that allow to override the checked Intranet Compatibility View. Just add in the OnInit event of your page this line (no meta or web.config customHeader need):

Response.AddHeader("X-UA-Compatible", "IE=EmulateIE8");

Working with UTF-8 encoding in Python source

In the source header you can declare:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

It is described in the PEP 0263:

Then you can use UTF-8 in strings:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

u = 'idzie waz waska drózka'
uu = u.decode('utf8')
s = uu.encode('cp1250')

This declaration is not needed in Python 3 as UTF-8 is the default source encoding (see PEP 3120).

In addition, it may be worth verifying that your text editor properly encodes your code in UTF-8. Otherwise, you may have invisible characters that are not interpreted as UTF-8.

Determining if a number is prime

You need to do some more checking. Right now, you are only checking if the number is divisible by 2. Do the same for 2, 3, 4, 5, 6, ... up to number. Hint: use a loop.

After you resolve this, try looking for optimizations. Hint: You only have to check all numbers up to the square root of the number

SQL Server using wildcard within IN

SELECT '071235' AS token UNION ALL SELECT '07113' 
SELECT '0712%' AS pattern UNION ALL SELECT '0711%' 
 UNION ALL SELECT '071343') AS d
ON c.token LIKE d.pattern


What is stability in sorting algorithms and why is it important?

Stable sort will always return same solution (permutation) on same input.

For instance [2,1,2] will be sorted using stable sort as permutation [2,1,3] (first is index 2, then index 1 then index 3 in sorted output) That mean that output is always shuffled same way. Other non stable, but still correct permutation is [2,3,1].

Quick sort is not stable sort and permutation differences among same elements depends on algorithm for picking pivot. Some implementations pick up at random and that can make quick sort yielding different permutations on same input using same algorithm.

Stable sort algorithm is necessary deterministic.

How to alias a table in Laravel Eloquent queries (or using Query Builder)?

Here is how one can do it. I will give an example with joining so that it becomes super clear to someone.

$products = DB::table('products AS pr')
        ->leftJoin('product_families AS pf', '', '=', 'pr.product_family_id')
        ->select(' as id', ' as product_family_name', ' as product_family_id')
        ->orderBy('', 'desc')

Hope this helps.

Start an Activity with a parameter

Put an int which is your id into the new Intent.

Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
Bundle b = new Bundle();
b.putInt("key", 1); //Your id
intent.putExtras(b); //Put your id to your next Intent

Then grab the id in your new Activity:

Bundle b = getIntent().getExtras();
int value = -1; // or other values
if(b != null)
    value = b.getInt("key");

How do you create an asynchronous HTTP request in JAVA?

If you are in a JEE7 environment, you must have a decent implementation of JAXRS hanging around, which would allow you to easily make asynchronous HTTP request using its client API.

This would looks like this:

public class Main {

    public static Future<Response> getAsyncHttp(final String url) {
        return ClientBuilder.newClient().target(url).request().async().get();

    public static void main(String ...args) throws InterruptedException, ExecutionException {
        Future<Response> response = getAsyncHttp("");
        while (!response.isDone()) {
            System.out.println("Still waiting...");

Of course, this is just using futures. If you are OK with using some more libraries, you could take a look at RxJava, the code would then look like:

public static void main(String... args) {
    final String url = "";
    rx.Observable.from(ClientBuilder.newClient().target(url).request().async().get(String.class), Schedulers
                    next -> System.out.println(next),
                    error -> System.err.println(error),
                    () -> System.out.println("Stream ended.")
    System.out.println("Async proof");

And last but not least, if you want to reuse your async call, you might want to take a look at Hystrix, which - in addition to a bazillion super cool other stuff - would allow you to write something like this:

For example:

public class AsyncGetCommand extends HystrixCommand<String> {

    private final String url;

    public AsyncGetCommand(final String url) {
        this.url = url;

    protected String run() throws Exception {
        return ClientBuilder.newClient().target(url).request().get(String.class);


Calling this command would look like:

public static void main(String ...args) {
    new AsyncGetCommand("").observe().subscribe(
            next -> System.out.println(next),
            error -> System.err.println(error),
            () -> System.out.println("Stream ended.")
    System.out.println("Async proof");

PS: I know the thread is old, but it felt wrong that no ones mentions the Rx/Hystrix way in the up-voted answers.

Uncaught TypeError: Cannot read property 'appendChild' of null

Instead of using your script tag defining the source of your .js file in <head>, place it at the bottom of your HTML code.

Detecting installed programs via registry

User-specific settings should be written to HKCU\Software, machine-specific settings to HKLM\Software. Under these keys, structure [software vendor name]\[application name] (e.g. HKLM\Software\Microsoft\Internet Explorer) may be the most common, but that's just a convention, not a law of nature.

Many (most?) applications also add their uninstall entries to HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\[app name], but again, not all applications do this.

These are the most important keys; however, contents of the registry do not have to represent the installed software exactly - maybe the application was installed once, but then was manually deleted, or maybe the uninstaller didn't remove all traces of it. If you want to be sure, check the filesystem to see if the application still exists where its registry entries say it is.


If you're a member of the group Administrators, you can check the HKEY_USERS hive - each user's HKCU actually resides there (you'll need to know the user SID, or go through all of them).

Note: As @Brian Ensink says, "installed" is a bit of a vague concept - are we trying to find what the user could run? Some software doesn't even write to the Registry at all: search for "portable apps" to see apps that have been specifically modified to run directly from media (CD/USB) and not to leave any traces on the computer. We may also have to scan the disks, and network disks, and anything the user downloads, and world-accessible Windows shares in the Internet (yes, such things exist legitimately - \\\tools comes to mind). In this direction, there's no real limit of what the user can run, unless prevented by system policies.

Getting mouse position in c#

Initialize the current cursor. Use it to get the position of X and Y

this.Cursor = new Cursor(Cursor.Current.Handle);
int posX = Cursor.Position.X;
int posY = Cursor.Position.Y;

Make function wait until element exists

Is better to relay in requestAnimationFrame than in a setTimeout. this is my solution in es6 modules and using Promises.

es6, modules and promises:

// onElementReady.js
const onElementReady = $element => (
  new Promise((resolve) => {
    const waitForElement = () => {
      if ($element) {
      } else {

export default onElementReady;

// in your app
import onElementReady from './onElementReady';

const $someElement = document.querySelector('.some-className');
  .then(() => {
    // your element is ready

plain js and promises:

var onElementReady = function($element) {
  return new Promise((resolve) => {
    var waitForElement = function() {
      if ($element) {
      } else {

var $someElement = document.querySelector('.some-className');
  .then(() => {
    // your element is ready

Is there a JSON equivalent of XQuery/XPath?

JMESPath seems to be very popular these days (as of 2020) and addresses a number of issues with JSONPath. It's available for many languages.

File Upload without Form

Try this puglin simpleUpload, no need form


<input type="file" name="arquivo" id="simpleUpload" multiple >
<button type="button" id="enviar">Enviar</button>


  url: 'upload.php',
  trigger: '#enviar',
  success: function(data){
    alert('Envio com sucesso');


Get all rows from SQLite

Cursor cursor = myDb.viewData();

        if (cursor.moveToFirst()){
              do {
                 String itemname=cursor.getString(cursor.getColumnIndex(myDb.col_2));
                 String price=cursor.getString(cursor.getColumnIndex(myDb.col_3));
                 String quantity=cursor.getString(cursor.getColumnIndex(myDb.col_4));
                 String table_no=cursor.getString(cursor.getColumnIndex(myDb.col_5));

                 }while (cursor.moveToNext());



Find CRLF in Notepad++

I opened the file in Notepad++ and did a replacement in a few steps:

  1. Replace all "\r\n" with " \r\n"
  2. Replace all "; \r\n" with "\r\n"
  3. Replace all " \r\n" with " "

This puts all the breaks where they should be and removes those that are breaking up the file.

It worked for me.

Python IndentationError unindent does not match any outer indentation level

make sure """ comments are only a tab away and not 5 spaces

Check if certain value is contained in a dataframe column in pandas

You can use any:

print any(df.column == 07311954)
True       #true if it contains the number, false otherwise

If you rather want to see how many times '07311954' occurs in a column you can use:

df.column[df.column == 07311954].count()

How to rollback everything to previous commit

I searched for multiple options to get my git reset to specific commit, but most of them aren't so satisfactory.

I generally use this to reset the git to the specific commit in source tree.

  1. select commit to reset on sourcetree.

  2. In dropdowns select the active branch , first Parent Only

  3. And right click on "Reset branch to this commit" and select hard reset option (soft, mixed and hard)

  4. and then go to terminal git push -f

You should be all set!

In Python, how to display current time in readable format

By using this code, you'll get your live time zone.

import datetime
now =
print ("Current date and time : ")
print (now.strftime("%Y-%m-%d %H:%M:%S"))

Reliable method to get machine's MAC address in C#

I really like AVee's solution with the lowest IP connection metric! But if a second nic with the same metric is installed, the MAC comparison could fail...

Better you store the description of the interface with the MAC. In later comparisons you can identify the right nic by this string. Here is a sample code:

   public static string GetMacAndDescription()
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_NetworkAdapterConfiguration where IPEnabled=true");
        IEnumerable<ManagementObject> objects = searcher.Get().Cast<ManagementObject>();
        string mac = (from o in objects orderby o["IPConnectionMetric"] select o["MACAddress"].ToString()).FirstOrDefault();
        string description = (from o in objects orderby o["IPConnectionMetric"] select o["Description"].ToString()).FirstOrDefault();
        return mac + ";" + description;

    public static string GetMacByDescription( string description)
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_NetworkAdapterConfiguration where IPEnabled=true");
        IEnumerable<ManagementObject> objects = searcher.Get().Cast<ManagementObject>();
        string mac = (from o in objects where o["Description"].ToString() == description select o["MACAddress"].ToString()).FirstOrDefault();
        return mac;

Why does git revert complain about a missing -m option?

Say the other guy created bar on top of foo, but you created baz in the meantime and then merged, giving a history of

$ git lola
*   2582152 (HEAD, master) Merge branch 'otherguy'
| * c7256de (otherguy) bar
* | b7e7176 baz
* 9968f79 foo

Note: git lola is a non-standard but useful alias.

No dice with git revert:

$ git revert HEAD
fatal: Commit 2582152... is a merge but no -m option was given.

Charles Bailey gave an excellent answer as usual. Using git revert as in

$ git revert --no-edit -m 1 HEAD
[master e900aad] Revert "Merge branch 'otherguy'"
 0 files changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 bar

effectively deletes bar and produces a history of

$ git lola
* e900aad (HEAD, master) Revert "Merge branch 'otherguy'"
*   2582152 Merge branch 'otherguy'
| * c7256de (otherguy) bar
* | b7e7176 baz
* 9968f79 foo

But I suspect you want to throw away the merge commit:

$ git reset --hard HEAD^
HEAD is now at b7e7176 baz

$ git lola
* b7e7176 (HEAD, master) baz
| * c7256de (otherguy) bar
* 9968f79 foo

As documented in the git rev-parse manual

<rev>^, e.g. HEAD^, v1.5.1^0
A suffix ^ to a revision parameter means the first parent of that commit object. ^<n> means the n-th parent (i.e. <rev>^ is equivalent to <rev>^1). As a special rule, <rev>^0 means the commit itself and is used when <rev> is the object name of a tag object that refers to a commit object.

so before invoking git reset, HEAD^ (or HEAD^1) was b7e7176 and HEAD^2 was c7256de, i.e., respectively the first and second parents of the merge commit.

Be careful with git reset --hard because it can destroy work.

Deep copy, shallow copy, clone

Unfortunately, "shallow copy", "deep copy" and "clone" are all rather ill-defined terms.

In the Java context, we first need to make a distinction between "copying a value" and "copying an object".

int a = 1;
int b = a;     // copying a value
int[] s = new int[]{42};
int[] t = s;   // copying a value (the object reference for the array above)

StringBuffer sb = new StringBuffer("Hi mom");
               // copying an object.
StringBuffer sb2 = new StringBuffer(sb);

In short, an assignment of a reference to a variable whose type is a reference type is "copying a value" where the value is the object reference. To copy an object, something needs to use new, either explicitly or under the hood.

Now for "shallow" versus "deep" copying of objects. Shallow copying generally means copying only one level of an object, while deep copying generally means copying more than one level. The problem is in deciding what we mean by a level. Consider this:

public class Example {
    public int foo;
    public int[] bar;
    public Example() { };
    public Example(int foo, int[] bar) { = foo; = bar; };

Example eg1 = new Example(1, new int[]{1, 2});
Example eg2 = ... 

The normal interpretation is that a "shallow" copy of eg1 would be a new Example object whose foo equals 1 and whose bar field refers to the same array as in the original; e.g.

Example eg2 = new Example(,;

The normal interpretation of a "deep" copy of eg1 would be a new Example object whose foo equals 1 and whose bar field refers to a copy of the original array; e.g.

Example eg2 = new Example(, Arrays.copy(;

(People coming from a C / C++ background might say that a reference assignment produces a shallow copy. However, that's not what we normally mean by shallow copying in the Java context ...)

Two more questions / areas of uncertainty exist:

  • How deep is deep? Does it stop at two levels? Three levels? Does it mean the whole graph of connected objects?

  • What about encapsulated data types; e.g. a String? A String is actually not just one object. In fact, it is an "object" with some scalar fields, and a reference to an array of characters. However, the array of characters is completely hidden by the API. So, when we talk about copying a String, does it make sense to call it a "shallow" copy or a "deep" copy? Or should we just call it a copy?

Finally, clone. Clone is a method that exists on all classes (and arrays) that is generally thought to produce a copy of the target object. However:

  • The specification of this method deliberately does not say whether this is a shallow or deep copy (assuming that is a meaningful distinction).

  • In fact, the specification does not even specifically state that clone produces a new object.

Here's what the javadoc says:

"Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression x.clone() != x will be true, and that the expression x.clone().getClass() == x.getClass() will be true, but these are not absolute requirements. While it is typically the case that x.clone().equals(x) will be true, this is not an absolute requirement."

Note, that this is saying that at one extreme the clone might be the target object, and at the other extreme the clone might not equal the original. And this assumes that clone is even supported.

In short, clone potentially means something different for every Java class.

Some people argue (as @supercat does in comments) that the Java clone() method is broken. But I think the correct conclusion is that the concept of clone is broken in the context of OO. AFAIK, it is impossible to develop a unified model of cloning that is consistent and usable across all object types.

How to increase buffer size in Oracle SQL Developer to view all records?

Here is another cheat:

Limit your query if you don't really need all the rows. i.e.

WHERE rownum <= 10000

Then click on any cell of the results and do from your keyboard CTRL+END. This will force SQL Developer to scroll until the bottom result of your query.

This has the advantage of keeping the default behavior and use this on demand.

What's the difference between a word and byte?


I am trying to answer this question from C++ perspective.

The C++ standard defines ‘byte’ as “Addressable unit of data large enough to hold any member of the basic character set of the execution environment.”

What this means is that the byte consists of at least enough adjacent bits to accommodate the basic character set for the implementation. That is, the number of possible values must equal or exceed the number of distinct characters. In the United States, the basic character sets are usually the ASCII and EBCDIC sets, each of which can be accommodated by 8 bits. Hence it is guaranteed that a byte will have at least 8 bits.

In other words, a byte is the amount of memory required to store a single character.

If you want to verify ‘number of bits’ in your C++ implementation, check the file ‘limits.h’. It should have an entry like below.

#define CHAR_BIT      8         /* number of bits in a char */


A Word is defined as specific number of bits which can be processed together (i.e. in one attempt) by the machine/system. Alternatively, we can say that Word defines the amount of data that can be transferred between CPU and RAM in a single operation.

The hardware registers in a computer machine are word sized. The Word size also defines the largest possible memory address (each memory address points to a byte sized memory).

Note – In C++ programs, the memory addresses points to a byte of memory and not to a word.

load scripts asynchronously

You might find this wiki article interesting :

It explains how and when to use such technique.

char initial value in Java

you can initialize it to ' ' instead. Also, the reason that you received an error -1 being too many characters is because it is treating '-' and 1 as separate.

PATH issue with pytest 'ImportError: No module named YadaYadaYada'

Also if you run pytest within your virtual environment make sure pytest module is installed within your virtual environment. Activate your virtual env and run pip install pytest.

Django: How can I call a view function from template?

For deleting all data:


  class="btn btn-primary" href="{% url 'delete_product'%}">Delete

Put the above code in an anchor tag. (the a tag!)

path('delete_product', views.delete_product, name='delete_product')]

def delete_product(request):
    if request.method == "GET":
        dest = Racket.objects.all()
        return render(request, "admin_page.html")

IN-clause in HQL or Java Persistence Query Language

Are you using Hibernate's Query object, or JPA? For JPA, it should work fine:

String jpql = "from A where name in (:names)";
Query q = em.createQuery(jpql);
q.setParameter("names", l);

For Hibernate's, you'll need to use the setParameterList:

String hql = "from A where name in (:names)";
Query q = s.createQuery(hql);
q.setParameterList("names", l);

Pass Javascript Array -> PHP

Here's a function to convert js array or object into a php-compatible array to be sent as http get request parameter:

function obj2url(prefix, obj) {
        var args=new Array();
        if(typeof(obj) == 'object'){
            for(var i in obj)
                args[args.length]=any2url(prefix+'['+encodeURIComponent(i)+']', obj[i]);
        return args.join('&');

prefix is a parameter name.


var a = {
    one: two,
    three: four

alert('/script.php?'+obj2url('a', a)); 

Will produce


which will allow you to use $_GET['a'] as an array in script.php. You will need to figure your way into your favorite ajax engine on supplying the url to call script.php from js.

Download JSON object as a file from browser

This is how I solved it for my application:

HTML: <a id="downloadAnchorElem" style="display:none"></a>

JS (pure JS, not jQuery here):

var dataStr = "data:text/json;charset=utf-8," + encodeURIComponent(JSON.stringify(storageObj));
var dlAnchorElem = document.getElementById('downloadAnchorElem');
dlAnchorElem.setAttribute("href",     dataStr     );
dlAnchorElem.setAttribute("download", "scene.json");;

In this case, storageObj is the js object you want to store, and "scene.json" is just an example name for the resulting file.

This approach has the following advantages over other proposed ones:

  • No HTML element needs to be clicked
  • Result will be named as you want it
  • no jQuery needed

I needed this behavior without explicit clicking since I want to trigger the download automatically at some point from js.

JS solution (no HTML required):

  function downloadObjectAsJson(exportObj, exportName){
    var dataStr = "data:text/json;charset=utf-8," + encodeURIComponent(JSON.stringify(exportObj));
    var downloadAnchorNode = document.createElement('a');
    downloadAnchorNode.setAttribute("href",     dataStr);
    downloadAnchorNode.setAttribute("download", exportName + ".json");
    document.body.appendChild(downloadAnchorNode); // required for firefox;

How to encode Doctrine entities to JSON in Symfony 2.0 AJAX application?

in Symfony 2.3


    # ?????? ??????????????? ???????? ? ???????, json, xml ? ???????
        enabled: true

        class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
        # ???????? ? ???? ????????? ???? ??????, ??? ??. ?????, ?.?. ????? ???????? ?? ?????
          - { name: serializer.normalizer }

and example for your controller:

 * ????? ???????? ?? ?? ??????? ? ?? ?????
 * @Route("/search/", name="orgunitSearch")
public function orgunitSearchAction()
    $array = $this->get('request')->query->all();

    $entity = $this->getDoctrine()

    $serializer = $this->get('serializer');
    //$json = $serializer->serialize($entity, 'json');
    $array = $serializer->normalize($entity);

    return new JsonResponse( $array );

but the problems with the field type \DateTime will remain.

Getting Checkbox Value in ASP.NET MVC 4

Since you are using Model.Name to set the value. I assume you are passing an empty view model to the View.

So the value for Remember is false, and sets the value on the checkbox element to false. This means that when you then select the checkbox, you are posting the value "false" with the form. When you don't select it, it doesn't get posted, so the model defaults to false. Which is why you are seeing a false value in both cases.

The value is only passed when you check the select box. To do a checkbox in Mvc use

@Html.CheckBoxFor(x => x.Remember)

or if you don't want to bind the model to the view.


Mvc does some magic with a hidden field to persist values when they are not selected.

Edit, if you really have an aversion to doing that and want to generate the element yourself, you could do.

<input id="Remember" name="Remember" type="checkbox" value="true" @(Model.Remember ? "checked=\"checked\"" : "") />

How do I implement __getattribute__ without an infinite recursion error?

How is the __getattribute__ method used?

It is called before the normal dotted lookup. If it raises AttributeError, then we call __getattr__.

Use of this method is rather rare. There are only two definitions in the standard library:

$ grep -Erl  "def __getattribute__\(self" cpython/Lib | grep -v "/test/"

Best Practice

The proper way to programmatically control access to a single attribute is with property. Class D should be written as follows (with the setter and deleter optionally to replicate apparent intended behavior):

class D(object):
    def __init__(self):

    def test(self):
        return 0.

    def test(self, value):
        '''dummy function to avoid AttributeError on setting property'''

    def test(self):
        '''dummy function to avoid AttributeError on deleting property'''

And usage:

>>> o = D()
>>> o.test
>>> o.test = 'foo'
>>> o.test
>>> del o.test
>>> o.test

A property is a data descriptor, thus it is the first thing looked for in the normal dotted lookup algorithm.

Options for __getattribute__

You several options if you absolutely need to implement lookup for every attribute via __getattribute__.

  • raise AttributeError, causing __getattr__ to be called (if implemented)
  • return something from it by
    • using super to call the parent (probably object's) implementation
    • calling __getattr__
    • implementing your own dotted lookup algorithm somehow

For example:

class NoisyAttributes(object):
    def __init__(self):
    def __getattribute__(self, name):
        print('getting: ' + name)
            return super(NoisyAttributes, self).__getattribute__(name)
        except AttributeError:
            print('oh no, AttributeError caught and reraising')
    def __getattr__(self, name):
        """Called if __getattribute__ raises AttributeError"""
        return 'close but no ' + name    

>>> n = NoisyAttributes()
>>> nfoo =
getting: foo
oh no, AttributeError caught and reraising
>>> nfoo
'close but no foo'
>>> n.test
getting: test

What you originally wanted.

And this example shows how you might do what you originally wanted:

class D(object):
    def __init__(self):
    def __getattribute__(self,name):
        if name=='test':
            return 0.
            return super(D, self).__getattribute__(name)

And will behave like this:

>>> o = D()
>>> o.test = 'foo'
>>> o.test
>>> del o.test
>>> o.test
>>> del o.test

Traceback (most recent call last):
  File "<pyshell#216>", line 1, in <module>
    del o.test
AttributeError: test

Code review

Your code with comments. You have a dotted lookup on self in __getattribute__. This is why you get a recursion error. You could check if name is "__dict__" and use super to workaround, but that doesn't cover __slots__. I'll leave that as an exercise to the reader.

class D(object):
    def __init__(self):
    def __getattribute__(self,name):
        if name=='test':
            return 0.
        else:      #   v--- Dotted lookup on self in __getattribute__
            return self.__dict__[name]

>>> print D().test
>>> print D().test2
RuntimeError: maximum recursion depth exceeded in cmp

Django templates: If false?

Just ran into this again (certain I had before and came up with a less-than-satisfying solution).

For a tri-state boolean semantic (for example, using models.NullBooleanField), this works well:

{% if test.passed|lower == 'false' %} ... {% endif %}

Or if you prefer getting excited over the whole thing...

{% if test.passed|upper == 'FALSE' %} ... {% endif %}

Either way, this handles the special condition where you don't care about the None (evaluating to False in the if block) or True case.

What is the "proper" way to cast Hibernate Query.list() to List<Type>?

You can avoid compiler warning with workarounds like this one:

List<?> resultRaw = query.list();
List<MyObj> result = new ArrayList<MyObj>(resultRaw.size());
for (Object o : resultRaw) {
    result.add((MyObj) o);

But there are some issues with this code:

  • created superfluous ArrayList
  • unnecessary loop over all elements returned from the query
  • longer code.

And the difference is only cosmetic, so using such workarounds is - in my opinion - pointless.

You have to live with these warnings or suppress them.

How to truncate the time on a DateTime object in Python?

Four years later: another way, avoiding replace

I know the accepted answer from four years ago works, but this seems a tad lighter than using replace:

dt =
dt = datetime.datetime(dt.year, dt.month,


  • When you create a datetime object without passing time properties to the constructor, you get midnight.
  • As others have noted, this assumes you want a datetime object for later use with timedeltas.
  • You can, of course, substitute this for the first line: dt =

How to get week numbers from dates?

if you try with lubridate:

lubridate::week(ymd("2014-03-16", "2014-03-17","2014-03-18", '2014-01-01'))

[1] 11 11 12  1

The pattern is the same. Try isoweek

lubridate::isoweek(ymd("2014-03-16", "2014-03-17","2014-03-18", '2014-01-01'))
[1] 11 12 12  1

Can I fade in a background image (CSS: background-image) with jQuery?

I know i'm late, but I found a way using jquery which works on every browser(i tested it on chrome, firefox and Ie 9)and th fore-ground elements are always displayed instead of css3 transition property.

create 2 absolute wrapper and using z-index.

First set the elements that have to be in the fore-ground with the highest z-index property value, and the other elemets(all included in the body, so: body{}) with a lower z-index property value than the fore-ground elements'one , at least of 2 number lower.

HTML part:

         <div class="wrapper" id="wrapper1"></div>
         <div class="wrapper" id="wrapper2"></div>

css part:

        .fore-groundElements{              //select all fore-ground elements
                  z-index:0;               //>=0
                  background-size: cover;
                  background-size: 100% 100%;



              z-index:-3                          //<=-3

than the javascript/jquery one:

i needed to change the background image every three second so i used a set timeout.

this is the code:


  var main = function(){

             var imgPath=[imagesPath1,..,...];                 // the array in which store the image paths

             var newWrapper;                     // the wrapper to display 
             var currentWrapper;                 //the current displayed wrapper which has to be faded
             var l=2;                             // the next image index  to be displayed, it is set to 2 because the first two position of the array(first two images) start already setted up
             var imgNumber= imgPath.length;        //to know when the images are over and restart the carousel
             var currentImg;                       //the next image path to be displayed

             $('#wrapper1').css("background-image", 'url'+imgPath[0]);         //pre set the first wrapper background images
             $('#wrapper2').css("background-image", 'url'+imgPath[1]);          //pre set the first wrapper background images   

             setInterval(myfunction,3000);                //refresh the background image every three seconds

             function myfunction(){
                    if(l===imgNumber-1){               //restart the carousel if every single image has already been displayed                  

             if(l%2==0||l%2==2){                    //set the wrapper that will be displaied after the fadeOut callback function
            $(currentWrapper).fadeOut(1000,function(){               //fade out the current wrapper, so now the back-ground wrapper is fully displayed
                  $(newWrapper).css("z-index", "-1");                //move the shown wrapper in the fore-ground
                  $(currentWrapper).css("z-index","-2");             //move the hidden wrapper in the back ground
                  $(currentWrapper).css("background-image",'url'+currentImg);                   // sets up the next image that is now shown in the actually hidden background wrapper
                  $(currentWrapper).show();          //shows the background wrapper, which is not visible yet, and it will be shown the next time the setInterval event will be triggered
                  l++;                         //set the next image index that will be set the next time the setInterval event will be triggered 

         };                   //end of myFunction
  }                          //end of main

i hope that my answer is clear,if you need more explanation comment it.

sorry for my english :)

html select only one checkbox in a group

The Code snippet below demonstrates a simple approach for selecting only one checkbox in a group.

  <!DOCTYPE html>
<script src=""></script>
    <h3>Demonstration of Checkbox Toggle</h3>
        A<input type="checkbox" name="A" >
        B<input type="checkbox" name="B" >
        C<input type="checkbox" name="C" >
        D<input type="checkbox" name="D" >
        1<input type="checkbox" name="1" >
        2<input type="checkbox" name="2" >
        3<input type="checkbox" name="3" >
        Scarlet Ibis<input type="checkbox" name="Scarlet Ibis" >
        Cocrico <input type="checkbox" name="Cocrico" >
        hummingbird <input type="checkbox" name="hummingbird" >

        function toggle(choices,name) 
                for( i=0;i<choices.length;i++)
                if(name !=choices[i])
                    $('input[name="' + choices[i] + '"]').not(this).prop('checked', false); 
        $('input[type="checkbox"]').on('change', function() 
            var letters = ["A","B","C","D"];
            var numbers = ["1", "2", "3"];
            var birds = ["Scarlet Ibis", "Cocrico", "hummingbird"];


Converting ISO 8601-compliant String to java.util.Date

Java 8+

Simple one liner that I didn't found in answers:

Date date = Date.from(ZonedDateTime.parse("2010-01-01T12:00:00+01:00").toInstant());

Date doesn't contain timezone, it will be stored in UTC, but will be properly converted to your JVM timezone even during simple output with System.out.println(date).

Add A Year To Today's Date

//This piece of code will handle the leap year addition as well.

function updateExpiryDate(controlID, value) {
    if ( $("#ICMEffectiveDate").val() != '' &&
        $("#ICMTermYears").val() != '') {

        var effectiveDate = $("#ICMEffectiveDate").val();
        var date = new Date(effectiveDate);
        var termYears = $("#ICMTermYears").val();

        date = new Date(date.setYear(date.getFullYear() + parseInt(termYears)));
        var expiryDate = (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();

Check if element is visible in DOM

If we're just collecting basic ways of detecting visibility, let me not forget:

opacity > 0.01; // probably more like .1 to actually be visible, but YMMV

And as to how to obtain attributes:


So, in your example:


But wha? It doesn't work here. Look closer and you'll find that visibility is being updated not as an attribute on the element, but using the style property. This is one of many problems with trying to do what you're doing. Among others: you can't guarantee that there's actually something to see in an element, just because its visibility, display, and opacity all have the correct values. It still might lack content, or it might lack a height and width. Another object might obscure it. For more detail, a quick Google search reveals this, and even includes a library to try solving the problem. (YMMV)

Check out the following, which are possible duplicates of this question, with excellent answers, including some insight from the mighty John Resig. However, your specific use-case is slightly different from the standard one, so I'll refrain from flagging:

(EDIT: OP SAYS HE'S SCRAPING PAGES, NOT CREATING THEM, SO BELOW ISN'T APPLICABLE) A better option? Bind the visibility of elements to model properties and always make visibility contingent on that model, much as Angular does with ng-show. You can do that using any tool you want: Angular, plain JS, whatever. Better still, you can change the DOM implementation over time, but you'll always be able to read state from the model, instead of the DOM. Reading your truth from the DOM is Bad. And slow. Much better to check the model, and trust in your implementation to ensure that the DOM state reflects the model. (And use automated testing to confirm that assumption.)

NTFS performance and large volumes of files and directories

100,000 should be fine.

I have (anecdotally) seen people having problems with many millions of files and I have had problems myself with Explorer just not having a clue how to count past 60-something thousand files, but NTFS should be good for the volumes you're talking.

In case you're wondering, the technical (and I hope theoretical) maximum number of files is: 4,294,967,295

How to make android listview scrollable?

You shouldn't put a ListView inside a ScrollView because the ListView class implements its own scrolling and it just doesn't receive gestures because they all are handled by the parent ScrollView

Regex to match only uppercase "words" with some exceptions

To some extent, this is going to vary by the "flavour" of RegEx you're using. The following is based on .NET RegEx, which uses \b for word boundaries. In the last example, it also uses negative lookaround (?<!) and (?!) as well as non-capturing parentheses (?:)

Basically, though, if the terms always contain at least one uppercase letter followed by at least one number, you can use


For all-uppercase and numbers (total must be 2 or more):


For all-uppercase and numbers, but starting with at least one letter:


The granddaddy, to return items that have any combination of uppercase letters and numbers, but which are not single letters at the beginning of a line and which are not part of a line that is all uppercase:

(?:(?<!^)[A-Z]\b|(?<!^[A-Z0-9 ]*)\b[A-Z0-9]+\b(?![A-Z0-9 ]$))


The regex starts with (?:. The ?: signifies that -- although what follows is in parentheses, I'm not interested in capturing the result. This is called "non-capturing parentheses." Here, I'm using the paretheses because I'm using alternation (see below).

Inside the non-capturing parens, I have two separate clauses separated by the pipe symbol |. This is alternation -- like an "or". The regex can match the first expression or the second. The two cases here are "is this the first word of the line" or "everything else," because we have the special requirement of excluding one-letter words at the beginning of the line.

Now, let's look at each expression in the alternation.

The first expression is: (?<!^)[A-Z]\b. The main clause here is [A-Z]\b, which is any one capital letter followed by a word boundary, which could be punctuation, whitespace, linebreak, etc. The part before that is (?<!^), which is a "negative lookbehind." This is a zero-width assertion, which means it doesn't "consume" characters as part of a match -- not really important to understand that here. The syntax for negative lookbehind in .NET is (?<!x), where x is the expression that must not exist before our main clause. Here that expression is simply ^, or start-of-line, so this side of the alternation translates as "any word consisting of a single, uppercase letter that is not at the beginning of the line."

Okay, so we're matching one-letter, uppercase words that are not at the beginning of the line. We still need to match words consisting of all numbers and uppercase letters.

That is handled by a relatively small portion of the second expression in the alternation: \b[A-Z0-9]+\b. The \bs represent word boundaries, and the [A-Z0-9]+ matches one or more numbers and capital letters together.

The rest of the expression consists of other lookarounds. (?<!^[A-Z0-9 ]*) is another negative lookbehind, where the expression is ^[A-Z0-9 ]*. This means what precedes must not be all capital letters and numbers.

The second lookaround is (?![A-Z0-9 ]$), which is a negative lookahead. This means what follows must not be all capital letters and numbers.

So, altogether, we are capturing words of all capital letters and numbers, and excluding one-letter, uppercase characters from the start of the line and everything from lines that are all uppercase.

There is at least one weakness here in that the lookarounds in the second alternation expression act independently, so a sentence like "A P1 should connect to the J9" will match J9, but not P1, because everything before P1 is capitalized.

It is possible to get around this issue, but it would almost triple the length of the regex. Trying to do so much in a single regex is seldom, if ever, justfied. You'll be better off breaking up the work either into multiple regexes or a combination of regex and standard string processing commands in your programming language of choice.

How I can check whether a page is loaded completely or not in web driver?

Below is some code from my BasePageObject class for waits:

public void waitForPageLoadAndTitleContains(int timeout, String pageTitle) {
    WebDriverWait wait = new WebDriverWait(driver, timeout, 1000);

public void waitForElementPresence(By locator, int seconds) {
    WebDriverWait wait = new WebDriverWait(driver, seconds);

public void jsWaitForPageToLoad(int timeOutInSeconds) {
    JavascriptExecutor js = (JavascriptExecutor) driver;
    String jsCommand = "return document.readyState";

    // Validate readyState before doing any waits
    if (js.executeScript(jsCommand).toString().equals("complete")) {

    for (int i = 0; i < timeOutInSeconds; i++) {
        if (js.executeScript(jsCommand).toString().equals("complete")) {

     * Looks for a visible OR invisible element via the provided locator for up
     * to maxWaitTime. Returns as soon as the element is found.
     * @param byLocator
     * @param maxWaitTime - In seconds
     * @return
    public WebElement findElementThatIsPresent(final By byLocator, int maxWaitTime) {
        if (driver == null) {
        FluentWait<WebDriver> wait = new FluentWait<>(driver).withTimeout(maxWaitTime, java.util.concurrent.TimeUnit.SECONDS)
                .pollingEvery(200, java.util.concurrent.TimeUnit.MILLISECONDS);

        try {
            return wait.until((WebDriver webDriver) -> {
                List<WebElement> elems = driver.findElements(byLocator);
                if (elems.size() > 0) {
                    return elems.get(0);
                } else {
                    return null;
        } catch (Exception e) {
            return null;

Supporting methods:

     * Gets locator.
     * @param fieldName
     * @return
    public By getBy(String fieldName) {
        try {
            return new Annotations(this.getClass().getDeclaredField(fieldName)).buildBy();
        } catch (NoSuchFieldException e) {
            return null;

Twitter Bootstrap 3.0 how do I "badge badge-important" now

In short: Replace badge-important with either alert-danger or progress-bar-danger.

It looks like this: Bootply Demo.

You might combine the CSS class badge with alert-* or progess-bar-* to color them:

With class="badges alert-*"

  <span class="badge alert-info">badge</span> Info
  <span class="badge alert-success">badge</span> Success 
  <span class="badge alert-danger">badge</span> Danger   
  <span class="badge alert-warning">badge</span> Warning

Alerts Docu:

With class="badges progress-bar-*" (as suggested by @clami219)

  <span class="badge progress-bar-info">badge</span> Info
  <span class="badge progress-bar-success">badge</span> Success
  <span class="badge progress-bar-danger">badge</span> Danger
  <span class="badge progress-bar-warning">badge</span> Warning

Progress-Bar Docu:

error: expected declaration or statement at end of input in c

For me I just noticed that it was my .h archive with a '{'. Maye that can help someone =)

Apache giving 403 forbidden errors

Notice that another issue that might be causing this is that, the "FollowSymLinks" option of a parent directory might have been mistakenly overwritten by the options of your project's directory. This was the case for me and made me pull my hair until I found out the cause!

Here's an example of such a mistake:

<Directory />
        Options FollowSymLinks
        AllowOverride all
        Require all denied

<Directory /var/www/>
        Options Indexes # <--- NOT OK! It's overwriting the above option of the "/" directory.
        AllowOverride all
        Require all granted

So now if you check the Apache's log message(tail -n 50 -f /var/www/html/{the_error_log_file_of_your_site}) you'll see such an error:

Options FollowSymLinks and SymLinksIfOwnerMatch are both off, so the RewriteRule directive
is also forbidden due to its similar ability to circumvent directory restrictions

That's because Indexes in the above rules for /var/www directory is overwriting the FolowSymLinks of the / directory. So now that you know the cause, in order to fix it, you can do many things depending on your need. For instance:

<Directory />
        Options FollowSymLinks
        AllowOverride all
        Require all denied

<Directory /var/www/>
        Options FollowSymLinks Indexes # <--- OK.
        AllowOverride all
        Require all granted

Or even this:

<Directory />
        Options FollowSymLinks
        AllowOverride all
        Require all denied

<Directory /var/www/>
        Options -Indexes # <--- OK as well! It will NOT cause an overwrite.
        AllowOverride all
        Require all granted

The example above will not cause the overwrite issue, because in Apache, if an option is "+" it will overwrite the "+"s only, and if it's a "-", it will overwrite the "-"s... (Don't ask me for a reference on that though, it's just my interpretation of an Apache's error message(checked through journalctl -xe) which says: Either all Options must start with + or -, or no Option may. when an option has a sign, but another one doesn't(E.g., FollowSymLinks -Indexes). So it's my personal conclusion -thus should be taken with a grain of salt- that if I've used -Indexes as the option, that will be considered as a whole distinct set of options by the Apache from the other option in the "/" which doesn't have any signs on it, and so no annoying rewrites will occur in the end, which I could successfully confirm by the above rules in a project directory of my own).

Hope that this will help you pull much less of your hair! :)

Is JavaScript a pass-by-reference or pass-by-value language?

well, it's about 'performance' and 'speed' and in the simple word 'memory management' in a programming language.

in javascript we can put values in two layer: type1-objects and type2-all other types of value such as string & boolean & etc

if you imagine memory as below squares which in every one of them just one type2-value can be saved:

enter image description here

every type2-value (green) is a single square while a type1-value (blue) is a group of them:

enter image description here

the point is that if you want to indicate a type2-value, the address is plain but if you want to do the same thing for type1-value that's not easy at all! :

enter image description here

and in a more complicated story:

enter image description here

so here references can rescue us: enter image description here

while the green arrow here is a typical variable, the purple one is an object variable, so because the green arrow(typical variable) has just one task (and that is indicating a typical value) we don't need to separate it's value from it so we move the green arrow with the value of that wherever it goes and in all assignments, functions and so on ...

but we cant do the same thing with the purple arrow, we may want to move 'john' cell here or many other things..., so the purple arrow will stick to its place and just typical arrows that were assigned to it will move ...

a very confusing situation is where you can't realize how your referenced variable changes, let's take a look at a very good example:

let arr = [1, 2, 3, 4, 5]; //arr is an object now and a purple arrow is indicating it
let obj2 = arr; // now, obj2 is another purple arrow that is indicating the value of arr obj
let obj3 = ['a', 'b', 'c'];
obj2.push(6); // first pic below - making a new hand for the blue circle to point the 6
//obj2 = [1, 2, 3, 4, 5, 6]
//arr = [1, 2, 3, 4, 5, 6]
//we changed the blue circle object value (type1-value) and due to arr and obj2 are indicating that so both of them changed
obj2 = obj3; //next pic below - changing the direction of obj2 array from blue circle to orange circle so obj2 is no more [1,2,3,4,5,6] and it's no more about changing anything in it but we completely changed its direction and now obj2 is pointing to obj3
//obj2 = ['a', 'b', 'c'];
//obj3 = ['a', 'b', 'c'];

enter image description here enter image description here

Validating Phone Numbers Using Javascript

As for your regexp I guess it should be

^\+{0,2}([\-\. ])?(\(?\d{0,3}\))?([\-\. ])?\(?\d{0,3}\)?([\-\. ])?\d{3}([\-\. ])?\d{4}

But in general the presumption is not correct because one might enter something like ++44 20 1234 56789 or +44 (0) 1234 567890 it is better to do something like this

var phone = document.forms["myForm"]["phone"].value;
var phoneNum = phone.replace(/[^\d]/g, '');
if(phoneNum.length > 6 && phoneNum.length < 11) {  return true;  }

this will assure that entered value has 7 to 10 figures nevertheless what the formatting is. But you have to think about max length for number might be more than 10 as in the sample above.

how to query LIST using linq

I would also suggest LinqPad as a convenient way to tackle with Linq for both advanced and beginners.

enter image description here

JWT (JSON Web Token) library for Java

This is a fork of original google jsontoken

It has not been updated since Sep 11, 2012 and depends on some old packages.

What I have done:

Convert from Joda time to Java 8 time. So it requires Java 8.
Covert Json parser from Gson to Jackson as I don't want to include two Json parsers to my projects.
Remove google collections from dependency list as it is stopped long time ago.
Fix thread safe issue with Java Mac.doFinal call.

All existing unit tests passed along with some newly added test cases.

Here is a sample to generate token and verify the token. For more information, please check source code for usage.

I am the author of both jsontoken and Omni-Channel Application Framework.

Get week of year in JavaScript like in PHP

Not ISO-8601 week number but if the search engine pointed you here anyways.

As said above but without a class:

let now = new Date();
let onejan = new Date(now.getFullYear(), 0, 1);
let week = Math.ceil( (((now.getTime() - onejan.getTime()) / 86400000) + onejan.getDay() + 1) / 7 );

jQuery exclude elements with certain class in selector

To add some info that helped me today, a jQuery object/this can also be passed in to the .not() selector.

    width: 100px;_x000D_
    background: red;_x000D_
    color: white;_x000D_
    display: inline-block;_x000D_
    position: relative;_x000D_
    text-align: center;_x000D_
<script src=""></script>_x000D_
<div class="navitem">Home</div>_x000D_
<div class="navitem">About</div>_x000D_
<div class="navitem">Pricing</div>

The above example can be simplified, but wanted to show the usage of this in the not() selector.

Solving SharePoint Server 2010 - 503. The service is unavailable, After installation

1) Ensure that the enable32BitAppOnWin64 setting for the "SharePoint Central Administration" app pool is set to False, and the same for the "SharePoint Web Services Root" app pool

2) Edit applicationHost.config:

bitness64 being the magic word here

How to create JNDI context in Spring Boot with Embedded Tomcat Container

Please note instead of

public TomcatEmbeddedServletContainerFactory tomcatFactory()

I had to use the following method signature

public EmbeddedServletContainerFactory embeddedServletContainerFactory() 

Apply Calibri (Body) font to text

If there is space between the letters of the font, you need to use quote.

font-family:"Calibri (Body)";

In React Native, how do I put a view on top of another view, with part of it lying outside the bounds of the view behind?

The easiest way to achieve this is with a negative margin.

const deviceWidth = RN.Dimensions.get('window').width

a: {
  alignItems: 'center',
  backgroundColor: 'blue',
  width: deviceWidth,
b: {
  marginTop: -16,
  marginStart: 20,

Trigger a Travis-CI rebuild without pushing a commit?

You can do this using the Travis CLI. As described in the documentation, first install the CLI tool, then:

travis login --org --auto
travis token

You can keep this token in an environment variable TRAVIS_TOKEN, as long as the file you keep it in is not version-controlled somewhere public.

I use this function to submit triggers:

function travis_trigger() {
     local org=$1 && shift
     local repo=$1 && shift
     local branch=${1:-master} && shift

             \"request\": {
               \"branch\": \"${branch}\"

     curl -s -X POST \
          -H "Content-Type: application/json" \
          -H "Accept: application/json" \
          -H "Travis-API-Version: 3" \
          -H "Authorization: token $TRAVIS_TOKEN" \
          -d "$body" \

Disable Pinch Zoom on Mobile Web

Found here you can use user-scalable=no:

<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">

Populate dropdown select with array using jQuery

The array declaration has incorrect syntax. Try the following, instead:

var numbers = [ 1, 2, 3, 4, 5]

The loop part seems right

$.each(numbers, function(val, text) {
            $('#items').append( $('<option></option>').val(val).html(text) )
            }); // there was also a ) missing here

As @Reigel did seems to add a bit more performance (it is not noticeable on such small arrays)

Managing large binary files with Git

You can also use git-fat. I like that it only depends on stock Python and rsync. It also supports the usual Git workflow, with the following self explanatory commands:

git fat init
git fat push
git fat pull

In addition, you need to check in a .gitfat file into your repository and modify your .gitattributes to specify the file extensions you want git fat to manage.

You add a binary using the normal git add, which in turn invokes git fat based on your gitattributes rules.

Finally, it has the advantage that the location where your binaries are actually stored can be shared across repositories and users and supports anything rsync does.

UPDATE: Do not use git-fat if you're using a Git-SVN bridge. It will end up removing the binary files from your Subversion repository. However, if you're using a pure Git repository, it works beautifully.

Difference between .dll and .exe?

I don't know why everybody is answering this question in context of .NET. The question was a general one and didn't mention .NET anywhere.

Well, the major differences are:


  1. An exe always runs in its own address space i.e., It is a separate process.
  2. The purpose of an EXE is to launch a separate application of its own.


  1. A dll always needs a host exe to run. i.e., it can never run in its own address space.
  2. The purpose of a DLL is to have a collection of methods/classes which can be re-used from some other application.
  3. DLL is Microsoft's implementation of a shared library.

The file format of DLL and exe is essentially the same. Windows recognizes the difference between DLL and EXE through PE Header in the file. For details of PE Header, You can have a look at this Article on MSDN

Why is the use of alloca() not considered good practice?

As noted in this newsgroup posting, there are a few reasons why using alloca can be considered difficult and dangerous:

  • Not all compilers support alloca.
  • Some compilers interpret the intended behaviour of alloca differently, so portability is not guaranteed even between compilers that support it.
  • Some implementations are buggy.

PHP 7 simpleXML

Had the same problem on AWS Linux 2, phpinfo() shows SimpleXML installed but not working, below cmd solved my issue

sudo yum install php-xml

Java string replace and the NUL (NULL, ASCII 0) character?

Should be probably changed to

firstName = firstName.trim().replaceAll("\\.", "");

Get the date (a day before current time) in Bash

date +%Y:%m:%d|awk -vFS=":" -vOFS=":" '{$3=$3-1;print}'

Convert month int to month name

    + "-" 
    + Convert.ToDateTime(e.Row.Cells[7].Text).ToString("yyyy");

Rolling or sliding window iterator?

Just to show how you can combine itertools recipes, I'm extending the pairwise recipe as directly as possible back into the window recipe using the consume recipe:

def consume(iterator, n):
    "Advance the iterator n-steps ahead. If n is none, consume entirely."
    # Use functions that consume iterators at C speed.
    if n is None:
        # feed the entire iterator into a zero-length deque
        collections.deque(iterator, maxlen=0)
        # advance to the empty slice starting at position n
        next(islice(iterator, n, n), None)

def window(iterable, n=2):
    "s -> (s0, ...,s(n-1)), (s1, ...,sn), (s2, ..., s(n+1)), ..."
    iters = tee(iterable, n)
    # Could use enumerate(islice(iters, 1, None), 1) to avoid consume(it, 0), but that's
    # slower for larger window sizes, while saving only small fixed "noop" cost
    for i, it in enumerate(iters):
        consume(it, i)
    return zip(*iters)

The window recipe is the same as for pairwise, it just replaces the single element "consume" on the second tee-ed iterator with progressively increasing consumes on n - 1 iterators. Using consume instead of wrapping each iterator in islice is marginally faster (for sufficiently large iterables) since you only pay the islice wrapping overhead during the consume phase, not during the process of extracting each window-ed value (so it's bounded by n, not the number of items in iterable).

Performance-wise, compared to some other solutions, this is pretty good (and better than any of the other solutions I tested as it scales). Tested on Python 3.5.0, Linux x86-64, using ipython %timeit magic.

kindall's the deque solution, tweaked for performance/correctness by using islice instead of a home-rolled generator expression and testing the resulting length so it doesn't yield results when the iterable is shorter than the window, as well as passing the maxlen of the deque positionally instead of by keyword (makes a surprising difference for smaller inputs):

>>> %timeit -r5 deque(windowkindall(range(10), 3), 0)
100000 loops, best of 5: 1.87 µs per loop
>>> %timeit -r5 deque(windowkindall(range(1000), 3), 0)
10000 loops, best of 5: 72.6 µs per loop
>>> %timeit -r5 deque(windowkindall(range(1000), 30), 0)
1000 loops, best of 5: 71.6 µs per loop

Same as previous adapted kindall solution, but with each yield win changed to yield tuple(win) so storing results from the generator works without all stored results really being a view of the most recent result (all other reasonable solutions are safe in this scenario), and adding tuple=tuple to the function definition to move use of tuple from the B in LEGB to the L:

>>> %timeit -r5 deque(windowkindalltupled(range(10), 3), 0)
100000 loops, best of 5: 3.05 µs per loop
>>> %timeit -r5 deque(windowkindalltupled(range(1000), 3), 0)
10000 loops, best of 5: 207 µs per loop
>>> %timeit -r5 deque(windowkindalltupled(range(1000), 30), 0)
1000 loops, best of 5: 348 µs per loop

consume-based solution shown above:

>>> %timeit -r5 deque(windowconsume(range(10), 3), 0)
100000 loops, best of 5: 3.92 µs per loop
>>> %timeit -r5 deque(windowconsume(range(1000), 3), 0)
10000 loops, best of 5: 42.8 µs per loop
>>> %timeit -r5 deque(windowconsume(range(1000), 30), 0)
1000 loops, best of 5: 232 µs per loop

Same as consume, but inlining else case of consume to avoid function call and n is None test to reduce runtime, particularly for small inputs where the setup overhead is a meaningful part of the work:

>>> %timeit -r5 deque(windowinlineconsume(range(10), 3), 0)
100000 loops, best of 5: 3.57 µs per loop
>>> %timeit -r5 deque(windowinlineconsume(range(1000), 3), 0)
10000 loops, best of 5: 40.9 µs per loop
>>> %timeit -r5 deque(windowinlineconsume(range(1000), 30), 0)
1000 loops, best of 5: 211 µs per loop

(Side-note: A variant on pairwise that uses tee with the default argument of 2 repeatedly to make nested tee objects, so any given iterator is only advanced once, not independently consumed an increasing number of times, similar to MrDrFenner's answer is similar to non-inlined consume and slower than the inlined consume on all tests, so I've omitted it those results for brevity).

As you can see, if you don't care about the possibility of the caller needing to store results, my optimized version of kindall's solution wins most of the time, except in the "large iterable, small window size case" (where inlined consume wins); it degrades quickly as the iterable size increases, while not degrading at all as the window size increases (every other solution degrades more slowly for iterable size increases, but also degrades for window size increases). It can even be adapted for the "need tuples" case by wrapping in map(tuple, ...), which runs ever so slightly slower than putting the tupling in the function, but it's trivial (takes 1-5% longer) and lets you keep the flexibility of running faster when you can tolerate repeatedly returning the same value.

If you need safety against returns being stored, inlined consume wins on all but the smallest input sizes (with non-inlined consume being slightly slower but scaling similarly). The deque & tupling based solution wins only for the smallest inputs, due to smaller setup costs, and the gain is small; it degrades badly as the iterable gets longer.

For the record, the adapted version of kindall's solution that yields tuples I used was:

def windowkindalltupled(iterable, n=2, tuple=tuple):
    it = iter(iterable)
    win = deque(islice(it, n), n)
    if len(win) < n:
    append = win.append
    yield tuple(win)
    for e in it:
        yield tuple(win)

Drop the caching of tuple in the function definition line and the use of tuple in each yield to get the faster but less safe version.

How do I use a custom deleter with a std::unique_ptr member?

It's possible to do this cleanly using a lambda in C++11 (tested in G++ 4.8.2).

Given this reusable typedef:

template<typename T>
using deleted_unique_ptr = std::unique_ptr<T,std::function<void(T*)>>;

You can write:

deleted_unique_ptr<Foo> foo(new Foo(), [](Foo* f) { customdeleter(f); });

For example, with a FILE*:

deleted_unique_ptr<FILE> file(
    fopen("file.txt", "r"),
    [](FILE* f) { fclose(f); });

With this you get the benefits of exception-safe cleanup using RAII, without needing try/catch noise.

Selecting specific rows and columns from NumPy array

As Toan suggests, a simple hack would be to just select the rows first, and then select the columns over that.

>>> a[[0,1,3], :]            # Returns the rows you want
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [12, 13, 14, 15]])
>>> a[[0,1,3], :][:, [0,2]]  # Selects the columns you want as well
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

[Edit] The built-in method: np.ix_

I recently discovered that numpy gives you an in-built one-liner to doing exactly what @Jaime suggested, but without having to use broadcasting syntax (which suffers from lack of readability). From the docs:

Using ix_ one can quickly construct index arrays that will index the cross product. a[np.ix_([1,3],[2,5])] returns the array [[a[1,2] a[1,5]], [a[3,2] a[3,5]]].

So you use it like this:

>>> a = np.arange(20).reshape((5,4))
>>> a[np.ix_([0,1,3], [0,2])]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

And the way it works is that it takes care of aligning arrays the way Jaime suggested, so that broadcasting happens properly:

>>> np.ix_([0,1,3], [0,2])
        [3]]), array([[0, 2]]))

Also, as MikeC says in a comment, np.ix_ has the advantage of returning a view, which my first (pre-edit) answer did not. This means you can now assign to the indexed array:

>>> a[np.ix_([0,1,3], [0,2])] = -1
>>> a    
array([[-1,  1, -1,  3],
       [-1,  5, -1,  7],
       [ 8,  9, 10, 11],
       [-1, 13, -1, 15],
       [16, 17, 18, 19]])

Easiest way to read/write a file's content in Python

with open('') as f: s =


EPPlus - Read Excel Table

Below code will read excel data into a datatable, which is converted to list of datarows.

if (FileUpload1.HasFile)
    if (Path.GetExtension(FileUpload1.FileName) == ".xlsx")
        Stream fs = FileUpload1.FileContent;
        ExcelPackage package = new ExcelPackage(fs);
        DataTable dt = new DataTable();
        dt= package.ToDataTable();
        List<DataRow> listOfRows = new List<DataRow>();
        listOfRows = dt.AsEnumerable().ToList();

using OfficeOpenXml;
using System.Data;
using System.Linq;

 public static class ExcelPackageExtensions
        public static DataTable ToDataTable(this ExcelPackage package)
            ExcelWorksheet workSheet = package.Workbook.Worksheets.First();
            DataTable table = new DataTable();
            foreach (var firstRowCell in workSheet.Cells[1, 1, 1, workSheet.Dimension.End.Column])

            for (var rowNumber = 2; rowNumber <= workSheet.Dimension.End.Row; rowNumber++)
                var row = workSheet.Cells[rowNumber, 1, rowNumber, workSheet.Dimension.End.Column];
                var newRow = table.NewRow();
                foreach (var cell in row)
                    newRow[cell.Start.Column - 1] = cell.Text;
            return table;


Remove blue border from css custom-styled button in Chrome

Another way to solve the accessibility problem that hasn't been mentioned here yet is through a little bit of Javascript. Credits go this insightful blogpost from hackernoon:

The approach here is really simple yet effective: Adding a class when people start using the tab-key to navigate the page (and optionally remove it when the switch to mouse again. Then you can use this class to either display a focus outline or not.

function handleFirstTab(e) {
    if (e.keyCode === 9) { // the "I am a keyboard user" key
        window.removeEventListener('keydown', handleFirstTab);

window.addEventListener('keydown', handleFirstTab);

Handling InterruptedException in Java

To me the key thing about this is: an InterruptedException is not anything going wrong, it is the thread doing what you told it to do. Therefore rethrowing it wrapped in a RuntimeException makes zero sense.

In many cases it makes sense to rethrow an exception wrapped in a RuntimeException when you say, I don't know what went wrong here and I can't do anything to fix it, I just want it to get out of the current processing flow and hit whatever application-wide exception handler I have so it can log it. That's not the case with an InterruptedException, it's just the thread responding to having interrupt() called on it, it's throwing the InterruptedException in order to help cancel the thread's processing in a timely way.

So propagate the InterruptedException, or eat it intelligently (meaning at a place where it will have accomplished what it was meant to do) and reset the interrupt flag. Note that the interrupt flag gets cleared when the InterruptedException gets thrown; the assumption the Jdk library developers make is that catching the exception amounts to handling it, so by default the flag is cleared.

So definitely the first way is better, the second posted example in the question is not useful unless you don't expect the thread to actually get interrupted, and interrupting it amounts to an error.

Here's an answer I wrote describing how interrupts work, with an example. You can see in the example code where it is using the InterruptedException to bail out of a while loop in the Runnable's run method.

Using a scanner to accept String input and storing in a String Array

Please correct me if I'm wrong.`

public static void main(String[] args) {

    Scanner na = new Scanner(;
    System.out.println("Please enter the number of contacts: ");
    int num = na.nextInt();

    String[] contactName = new String[num];
    String[] contactPhone = new String[num];
    String[] contactAdd1 = new String[num];
    String[] contactAdd2 = new String[num];

    Scanner input = new Scanner(;

    for (int i = 0; i < num; i++) {

        System.out.println("Enter contacts name: " + (i+1));
        contactName[i] = input.nextLine();

        System.out.println("Enter contacts addressline1: " + (i+1));
        contactAdd1[i] = input.nextLine();

        System.out.println("Enter contacts addressline2: " + (i+1));
        contactAdd2[i] = input.nextLine();

        System.out.println("Enter contact phone number: " + (i+1));
        contactPhone[i] = input.nextLine();


    for (int i = 0; i < num; i++) {
        System.out.println("Contact Name No." + (i+1) + " is "+contactName[i]);
        System.out.println("First Contacts Address No." + (i+1) + " is "+contactAdd1[i]);
        System.out.println("Second Contacts Address No." + (i+1) + " is "+contactAdd2[i]);
        System.out.println("Contact Phone Number No." + (i+1) + " is "+contactPhone[i]);


Building a fat jar using maven

You can use the onejar-maven-plugin for packaging. Basically, it assembles your project and its dependencies in as one jar, including not just your project jar file, but also all external dependencies as a "jar of jars", e.g.


Note 1: Configuration options is available at the project home page.

Note 2: For one reason or the other, the onejar-maven-plugin project is not published at Maven Central. However tracks the original project and publishes it to with the groupId com.jolira.

Saving to CSV in Excel loses regional date format

If you use a Custom format, rather than one of the pre-selected Date formats, the export to CSV will keep your selected format. Otherwise it defaults back to the US format

Angular: How to download a file from HttpClient?

After spending much time searching for a response to this answer: how to download a simple image from my API restful server written in Node.js into an Angular component app, I finally found a beautiful answer in this web Angular HttpClient Blob. Essentially it consist on:

API Node.js restful:

   /* After routing the path you want ..*/
  public getImage( req: Request, res: Response) {

    // Check if file exist...
    if (!req.params.file) {
      return res.status(httpStatus.badRequest).json({
        ok: false,
        msg: 'File param not found.'
    const absfile = path.join(STORE_ROOT_DIR,IMAGES_DIR, req.params.file);

    if (!fs.existsSync(absfile)) {
      return res.status(httpStatus.badRequest).json({
        ok: false,
        msg: 'File name not found on server.'

Angular 6 tested component service (EmployeeService on my case):

  downloadPhoto( name: string) : Observable<Blob> {
    const url = environment.api_url + '/storer/employee/image/' + name;

    return this.http.get(url, { responseType: 'blob' })
        takeWhile( () => this.alive),
        filter ( image => !!image));


 <img [src]="" class="custom-photo" #photo>

Component subscriber and use:

@ViewChild('photo') image: ElementRef;

public LoadPhoto( name: string) {
          .subscribe( image => {
            const url= window.URL.createObjectURL(image);
            this.image.nativeElement.src= url;
          }, error => {
            console.log('error downloading: ', error);

How to retrieve absolute path given relative

Here's a rather short function that can be used to fully absolutize and canonicalize any given input path using only POSIX shell and readlink semantics:

canonicalize_path() {
        for _ in 1 2 3 4 5 6 7 8;  # Maximum symlink recursion depth
            cd -L "`case "${FILEPATH}" in */*) echo "${FILEPATH%/*}";; *) echo ".";; esac`/"  # cd $(dirname)
            if ! FILEPATH="$(readlink "${FILEPATH##*/}" || ( echo "${FILEPATH##*/}" && false ) )";
        cd -P "." || return $?
        echo "$(pwd)/${FILEPATH}"

If the referenced file does not exist only the directory path leading up to the final filename will be resolved. If the any of the directories leading up to the file path does not exist a cd error will be returned. This happens to be the exact semantics of the GNU/Linux readlink -f command it tries to mimic.

In bash/zsh you can also compact the list of numbers to just {1..8} or similar. The number of 8 was chosen as this was maximum limit in Linux for many years before the changed it a total limit of 40 resolution for the entire path in version 4.2. If the resolution limit is reached the code will not fail, but instead return last considered path instead – an explicit [ -L "${FILEPATH}" ] check could be added to detect this condition however.

This code can also be easily reused for ensuring the current working directory matches the executed script's location in the filesystem (a common requirement for shell scripts), by simply removing the function and subshell wrapper:

for _ in 1 2 3 4 5 6 7 8;  # Maximum symlink recursion depth
    cd -L "`case "${FILEPATH}" in */*) echo "${FILEPATH%/*}";; *) echo ".";; esac`/"  # cd $(dirname)
    if ! FILEPATH="$(readlink "${FILEPATH##*/}" || ( echo "${FILEPATH##*/}" && false ) )";
cd -P "."

Android Activity without ActionBar

open Manifest and add attribute theme = "@style/Theme.AppCompat.Light.NoActionBar" to activity you want it without actionbar :

    <activity android:name=".MainActivity"

Lock screen orientation (Android)

In the Manifest, you can set the screenOrientation to landscape. It would look something like this in the XML:

<activity android:name="MyActivity"

Where MyActivity is the one you want to stay in landscape.

The android:configChanges=... line prevents onResume(), onPause() from being called when the screen is rotated. Without this line, the rotation will stay as you requested but the calls will still be made.

Note: keyboardHidden and orientation are required for < Android 3.2 (API level 13), and all three options are required 3.2 or above, not just orientation.

git: fatal unable to auto-detect email address

Probably a typo mistake: set user.mail with no e. Fix it by setting in the Global Configuration with

$ git config --global "[email protected]"

Already been asked: Why Git is not allowing me to commit even after configuration?

To be sure Run:

$ git config --local -l

How to see the changes in a Git commit?

I'm running Git version on Windows 10, so I needed a slight modification to Nevik's answer (tilde instead of caret):


Another option is to quote the caret:

git diff "COMMIT^" COMMIT

Apache Prefork vs Worker MPM

Its easy to switch between prefork or worker mpm in Apache 2.4 on RHEL7

Check MPM type by executing

sudo httpd -V

Server version: Apache/2.4.6 (Red Hat Enterprise Linux)
Server built:   Jul 26 2017 04:45:44
Server's Module Magic Number: 20120211:24
Server loaded:  APR 1.4.8, APR-UTIL 1.5.2
Compiled using: APR 1.4.8, APR-UTIL 1.5.2
Architecture:   64-bit
Server MPM:     prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_PIDLOG="/run/httpd/"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

Now to change MPM edit following file and uncomment required MPM


# Select the MPM module which should be used by uncommenting exactly
# one of the following LoadModule lines:

# prefork MPM: Implements a non-threaded, pre-forking web server
# See:
LoadModule mpm_prefork_module modules/

# worker MPM: Multi-Processing Module implementing a hybrid
# multi-threaded multi-process web server
# See:
#LoadModule mpm_worker_module modules/

# event MPM: A variant of the worker MPM with the goal of consuming
# threads only for connections with active processing
# See:
#LoadModule mpm_event_module modules/

How to run only one task in ansible playbook?

This can be easily done using the tags

The example of tags is defined below:

hosts: localhost
 - name: Creating s3Bucket
        name: ansiblebucket1234567890
       - createbucket

 - name: Simple PUT operation
       bucket: ansiblebucket1234567890
       object: /my/desired/key.txt
       src: /etc/ansible/myfile.txt
       mode: put
      - putfile

 - name: Create an empty bucket
       bucket: ansiblebucket12345678901234
       mode: create
       permission: private
       - emptybucket

to execute the tags we use the command

ansible-playbook creates3bucket.yml --tags "createbucket,putfile"

How do I measure execution time of a command on the Windows command line?

Here is a

Postfix timer version:

Usage example:

timeout 1 | TimeIt.cmd

Execution took  ~969 milliseconds.

Copy & paste this into some editor like for example Notepad++ and save it as TimeIt.cmd:

:: --- TimeIt.cmd ----
    @echo off
    setlocal enabledelayedexpansion

    call :ShowHelp

    :: Set pipeline initialization time
    set t1=%time%

    :: Wait for stdin

    :: Set time at which stdin was ready
    set t2=!time!

    :: Calculate difference
    Call :GetMSeconds Tms1 t1
    Call :GetMSeconds Tms2 t2

    set /a deltaMSecs=%Tms2%-%Tms1%
    echo Execution took ~ %deltaMSecs% milliseconds.

goto :eof

    Call :Parse        TimeAsArgs %2
    Call :CalcMSeconds %1 %TimeAsArgs%

goto :eof

    set /a %1= (%2 * 3600*1000) + (%3 * 60*1000) + (%4 * 1000) + (%5)
goto :eof


    :: Mask time like " 0:23:29,12"
    set %1=!%2: 0=0!

    :: Replace time separators with " "
    set %1=!%1::= !
    set %1=!%1:.= !
    set %1=!%1:,= !

    :: Delete leading zero - so it'll not parsed as octal later
    set %1=!%1: 0= !
goto :eof

    echo %~n0 V1.0 [Dez 2015]
    echo Usage: ^<Command^> ^| %~nx0
    echo Wait for pipe getting ready... :)
    echo  (Press Ctrl+Z ^<Enter^> to Cancel)
goto :eof

^ - Based on 'Daniel Sparks' Version

Convert pandas DataFrame into list of lists

you can do it like this:

map(list, df.values)

Find all files in a directory with extension .txt in Python

Here's one with extend()

types = ('*.jpg', '*.png')
images_list = []
for files in types:
    images_list.extend(glob.glob(os.path.join(path, files)))

"Could not find or load main class" Error while running java program using cmd prompt

faced the same problem. solved by following these steps

  • go to directory containing the package 'org.tij.exercises' (e.g: in eclipse it may be your src folder)
  • use java org.tij.exercises.HelloWorld

How to specify the download location with wget?

"-P" is the right option, please read on for more related information:

wget -nd -np -P /dest/dir --recursive http://url/dir1/dir2

Relevant snippets from man pages for convenience:

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

       Do not create a hierarchy of directories when retrieving recursively.  With this option turned on, all files will get saved to the current directory, without clobbering (if a name shows up more than once, the
       filenames will get extensions .n).

       Do not ever ascend to the parent directory when retrieving recursively.  This is a useful option, since it guarantees that only the files below a certain hierarchy will be downloaded.

How to pass values arguments to function in Bootstrap

You could do it like this:

<a class="btn btn-primary announce" data-toggle="modal" data-id="107" >Announce</a>

Then use jQuery to bind the click and send the Announce data-id as the value in the modals #cafeId:

   $(".announce").click(function(){ // Click to only happen on announce links

laravel 5.5 The page has expired due to inactivity. Please refresh and try again

If you have already included the CSRF token in your form. Then you are getting the error page possibly because of cache data in your form.

Open your terminal/command prompt and run these commands in your project root.

  1. php artisan cache:clear
  2. php artisan config:clear
  3. php artisan route:clear
  4. php artisan view:clear,

Also try to clear the browser cache along with running these commands.

Garbage collector in Android

For versions prior to 3.0 honeycomb: Yes, do call System.gc().

I tried to create Bitmaps, but was always getting "VM out of memory error". But, when I called System.gc() first, it was OK.

When creating bitmaps, Android often fails with out of memory errors, and does not try to garbage collect first. Hence, call System.gc(), and you have enough memory to create Bitmaps.

If creating Objects, I think System.gc will be called automatically if needed, but not for creating bitmaps. It just fails.

So I recommend manually calling System.gc() before creating bitmaps.

What's "tools:context" in Android layout files?

According to the Android Tools Project Site:


This attribute is typically set on the root element in a layout XML file, and records which activity the layout is associated with (at designtime, since obviously a layout can be used by more than one layout). This will for example be used by the layout editor to guess a default theme, since themes are defined in the Manifest and are associated with activities, not layouts. You can use the same dot prefix as in manifests to just specify the activity class without the full application package name as a prefix.


Used by: Layout editors in Studio & Eclipse, Lint

Java: Get first item from a collection

You can do a casting. For example, if exists one method with this definition, and you know that this method is returning a List:

Collection<String> getStrings();

And after invoke it, you need the first element, you can do it like this:

List<String> listString = (List) getStrings();
String firstElement = (listString.isEmpty() ? null : listString.get(0));

Spring boot - configure EntityManager

Hmmm you can find lot of examples for configuring spring framework. Anyways here is a sample

@ComponentScan(basePackageClasses = { 
    RepositoryMarker.class }
public class AppConfig {



@PropertySource(value = { "classpath:database/" })
public class PersistenceConfig {

    private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
    private static final String PROPERTY_NAME_HIBERNATE_MAX_FETCH_DEPTH = "hibernate.max_fetch_depth";
    private static final String PROPERTY_NAME_HIBERNATE_JDBC_FETCH_SIZE = "hibernate.jdbc.fetch_size";
    private static final String PROPERTY_NAME_HIBERNATE_JDBC_BATCH_SIZE = "hibernate.jdbc.batch_size";
    private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";
    private static final String[] ENTITYMANAGER_PACKAGES_TO_SCAN = {"a.b.c.entities", "a.b.c.converters"};

    private Environment env;

     @Bean(destroyMethod = "close")
     public DataSource dataSource() {
         BasicDataSource dataSource = new BasicDataSource();
         return dataSource;

     public JpaTransactionManager jpaTransactionManager() {
         JpaTransactionManager transactionManager = new JpaTransactionManager();
         return transactionManager;

    private HibernateJpaVendorAdapter vendorAdaptor() {
         HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
         return vendorAdapter;

    public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean() {

         LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();

         return entityManagerFactoryBean;

     private Properties jpaHibernateProperties() {

         Properties properties = new Properties();


         properties.put(AvailableSettings.SCHEMA_GEN_DATABASE_ACTION, "none");
         properties.put(AvailableSettings.USE_CLASS_ENHANCER, "false");      
         return properties;       



public static void main(String[] args) { 
    try (GenericApplicationContext springContext = new AnnotationConfigApplicationContext(AppConfig.class)) {
        MyService myService = springContext.getBean(MyServiceImpl.class);
        try {
            myService.handleProcess(fromDate, toDate);
        } catch (Exception e) {
            logger.error("Exception occurs", e);
            myService.handleException(fromDate, toDate, e);
    } catch (Exception e) {
        logger.error("Exception occurs in loading Spring context: ", e);


public class MyServiceImpl implements MyService {

    private MyDao myDao;

    public void handleProcess(String fromDate, String toDate) {
        List<Student> myList =, toDate);


public class MyDaoImpl implements MyDao {

    private EntityManager entityManager;

    public Student select(String fromDate, String toDate){

        TypedQuery<Student> query = entityManager.createNamedQuery("Student.findByKey", Student.class);
        query.setParameter("fromDate", fromDate);
        query.setParameter("toDate", toDate);
        List<Student> list = query.getResultList();
        return CollectionUtils.isEmpty(list) ? null : list;


Assuming maven project: Properties file should be in src/main/resources/database folder file

jdbc.url=your db url
jdbc.username=your Username
jdbc.password=Your password

hibernate.max_fetch_depth = 3
hibernate.jdbc.fetch_size = 50
hibernate.jdbc.batch_size = 10
hibernate.show_sql = true

ServiceMarker and RepositoryMarker are just empty interfaces in your service or repository impl package.

Let's say you have package name a.b.c.service.impl. MyServiceImpl is in this package and so is ServiceMarker.

public interface ServiceMarker {


Same for repository marker. Let's say you have a.b.c.repository.impl or a.b.c.dao.impl package name. Then MyDaoImpl is in this this package and also Repositorymarker

public interface RepositoryMarker {



//dummy class and dummy query
@NamedQuery(name="Student.findByKey", query="select s from Student s where s.fromDate=:fromDate" and s.toDate = :toDate)
public class Student implements Serializable {

    private LocalDateTime fromDate;
    private LocalDateTime toDate;

    //getters setters



@Converter(autoApply = true)
public class LocalDateTimeConverter implements AttributeConverter<LocalDateTime, Timestamp> {

    public Timestamp convertToDatabaseColumn(LocalDateTime dateTime) {

        if (dateTime == null) {
            return null;
        return Timestamp.valueOf(dateTime);

    public LocalDateTime convertToEntityAttribute(Timestamp timestamp) {

        if (timestamp == null) {
            return null;
        return timestamp.toLocalDateTime();




    <!-- Spring -->









Hope it helps. Thanks

Compiler error "archive for required library could not be read" - Spring Tool Suite

Delete corrupted files from your local .m2 repository and Ctrl+F5 (Update Maven Project) in Eclipse/STS. It'll download and install these files.

How can I know if a branch has been already merged into master?

On the topic of cleaning up remote branches

git branch -r | xargs -t -n 1 git branch -r --contains

This lists each remote branch followed by which remote branches their latest SHAs are within.

This is useful to discern which remote branches have been merged but not deleted, and which haven't been merged and thus are decaying.

If you're using 'tig' (its like gitk but terminal based) then you can

tig origin/feature/someones-decaying-feature

to see a branch's commit history without having to git checkout

How to run java application by .bat file

Simply create a .bat file with the following lines in it:

set CLASSPATH=%CLASSPATH%;path/to/needed/jars/my.jar

%JAVA_HOME%\bin\java -Xms128m -Xmx384m -Xnoclassgc

How to handle a lost KeyStore password in Android?

IF you're able to build your app from a PC, but you don't recall the password, here's what you can do to retrieve the password:

Method 1:

In your build.gradle, add println MYAPP_RELEASE_KEY_PASSWORD as below:

signingConfigs {
    release {
        if (project.hasProperty('MYAPP_RELEASE_STORE_FILE')) {
            storeFile file(MYAPP_RELEASE_STORE_FILE)
            storePassword MYAPP_RELEASE_STORE_PASSWORD
            keyAlias MYAPP_RELEASE_KEY_ALIAS
            keyPassword MYAPP_RELEASE_KEY_PASSWORD
            println MYAPP_RELEASE_KEY_PASSWORD

After that, run cd android && ./gradlew assembleRelease

Method 2:

Run keytool -list -v -keystore your <.keystore file path> e.g. keytool -list -v -keystore ./app/my-app-key.keystore.

It will ask for you to Enter keystore password: Just press enter key here. and you will be able to find mapped to Alias name:

Then, run grep -rn "<your alias name>" . in your terminal and you will be able to see your signing.json file as below:


The file will have your password in json format with key "mKeyPassword":" < your password > "

Android SDK Manager Not Installing Components

The Access denied is because Windows doesn't give the default write and modify permission to the files in its install drive viz. c: To resolve this issue I usually use a separate drive or in your case, you need to set the access rights to the specific folder in the options right click -> options > security -> edit enter image description here

Unix: How to delete files listed in a file

Here you can use set of folders from deletelist.txt while avoiding some patterns as well

foreach f (cat deletelist.txt)
    rm -rf ls | egrep -v "needthisfile|*.cpp|*.h"

How to change owner of PostgreSql database?


See the Postgresql manual's entry on this for more details.

PHP: How to use array_filter() to filter array keys?

How to get the current key of an array when using array_filter

Regardless of how I like Vincent's solution for Macek's problem, it doesn't actually use array_filter. If you came here from a search engine you maybe where looking for something like this (PHP >= 5.3):

$array = ['apple' => 'red', 'pear' => 'green'];
reset($array); // Unimportant here, but make sure your array is reset

$apples = array_filter($array, function($color) use ($&array) {
  $key = key($array);
  next($array); // advance array pointer

  return key($array) === 'apple';

It passes the array you're filtering as a reference to the callback. As array_filter doesn't conventionally iterate over the array by increasing it's public internal pointer you have to advance it by yourself.

What's important here is that you need to make sure your array is reset, otherwise you might start right in the middle of it.

In PHP >= 5.4 you could make the callback even shorter:

$apples = array_filter($array, function($color) use ($&array) {
  return each($array)['key'] === 'apple';

Angular 2: import external js file into component

After wasting a lot of time in finding its solution, I've found one. For your convenience I've used the complete code that you can replace your whole file with.

This is a general answer. Let's say you want to import a file named testjs.js into your angular 2 component. Create testjs.js in your assets folder:

assets > testjs.js

function test(){

include testjs.js in your index.html


<!doctype html>
  <meta charset="utf-8">
  <base href="/">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/x-icon" href="favicon.ico">

  <script src="./assets/testjs.js"></script>


In your app.component.ts or in any component.ts file where you want to call this js declare a variable and call the function like below:


import { Component } from '@angular/core';

declare var test: any;

  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']

export class AppComponent {
  title = 'app works!';

    new test();

Finally in your app.component.html test the function


  <button (click)='f()'>Test</button>

Pass variables to Ruby script via command line

You can also try out cliqr. Its pretty new and in active development. But there are stable releases ready to be used. Here is the git repo:

Look into the example folder to get an idea on how it can be used.

How to initialize array to 0 in C?

If you'd like to initialize the array to values other than 0, with gcc you can do:

int array[1024] = { [ 0 ... 1023 ] = -1 };

This is a GNU extension of C99 Designated Initializers. In older GCC, you may need to use -std=gnu99 to compile your code.

Cannot obtain value of local or argument as it is not available at this instruction pointer, possibly because it has been optimized away

When I was faced with the same problem I just had to clean my solution before rebuilding. That took care of it for me.

Why is String immutable in Java?

String is immutable for several reasons, here is a summary:

  • Security: parameters are typically represented as String in network connections, database connection urls, usernames/passwords etc. If it were mutable, these parameters could be easily changed.
  • Synchronization and concurrency: making String immutable automatically makes them thread safe thereby solving the synchronization issues.
  • Caching: when compiler optimizes your String objects, it sees that if two objects have same value (a="test", and b="test") and thus you need only one string object (for both a and b, these two will point to the same object).
  • Class loading: String is used as arguments for class loading. If mutable, it could result in wrong class being loaded (because mutable objects change their state).

That being said, immutability of String only means you cannot change it using its public API. You can in fact bypass the normal API using reflection. See the answer here.

In your example, if String was mutable, then consider the following example:

  String a="stack";
  System.out.println(a);//prints stack
  System.out.println(a);//if mutable it would print overflow

How to rename a file using Python

Use os.rename. But you have to pass full path of both files to the function. If I have a file a.txt on my desktop so I will do and also I have to give full of renamed file too.

os.rename('C:\\Users\\Desktop\\a.txt', 'C:\\Users\\Desktop\\b.kml')

Assign null to a SqlParameter

You need pass DBNull.Value as a null parameter within SQLCommand, unless a default value is specified within stored procedure (if you are using stored procedure). The best approach is to assign DBNull.Value for any missing parameter before query execution, and following foreach will do the job.

foreach (SqlParameter parameter in sqlCmd.Parameters)
    if (parameter.Value == null)
        parameter.Value = DBNull.Value;

Otherwise change this line:

planIndexParameter.Value = (AgeItem.AgeIndex== null) ? DBNull.Value : AgeItem.AgeIndex;

As follows:

if (AgeItem.AgeIndex== null)
    planIndexParameter.Value = DBNull.Value;
    planIndexParameter.Value = AgeItem.AgeIndex;

Because you can't use different type of values in conditional statement, as DBNull and int are different from each other. Hope this will help.

jQuery get an element by its data-id


How to change the floating label color of TextInputLayout

To change color of hint and edit text underline color : colorControlActivated

To change character counter color : textColorSecondary

To change error message color : colorControlNormal

To change password visibility button tint : colorForeground

For more info on TextInputLayout read

<style name="MyAppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorControlActivated">#e91e63</item>
    <item name="android:colorForeground">#33691e</item>
    <item name="colorControlNormal">#f57f17</item>
    <item name="android:textColorSecondary">#673ab7</item>

How to abort makefile if variable not set?

Use the shell function test:

    test $(something)


$ make foo
Makefile:2: recipe for target 'foo' failed
make: *** [foo] Error 1
$ make foo something=x
test x

Scale an equation to fit exact page width




Populating a dictionary using for loops (python)

dicts = {}
keys = range(4)
values = ["Hi", "I", "am", "John"]
for i in keys:
        dicts[i] = values[i]


In [7]: dict(list(enumerate(values)))
Out[7]: {0: 'Hi', 1: 'I', 2: 'am', 3: 'John'}

Emulate a 403 error page

Seen a lot of the answers, but the correct one is to provide the full options for the header function call as per the php manual

void header ( string $string [, bool $replace = true [, int $http_response_code ]] )

If you invoke with

header('HTTP/1.0 403 Forbidden', true, 403);

the normal behavior of HTTP 403 as configured with Apache or any other server would follow.

How to grant "grant create session" privilege?

You can grant system privileges with or without the admin option. The default being without admin option.


or with admin option:


The Grantee with the ADMIN OPTION can grant and revoke privileges to other users

src absolute path problem

You should be referencing it as localhost. Like this:

<img src="http:\\localhost\site\img\mypicture.jpg"/>

Removing header column from pandas dataframe

I had the same problem but solved it in this way:

df = pd.read_csv('your-array.csv', skiprows=[0])

%matplotlib line magic causes SyntaxError in Python script

Line magics are only supported by the IPython command line. They cannot simply be used inside a script, because %something is not correct Python syntax.

If you want to do this from a script you have to get access to the IPython API and then call the run_line_magic function.

Instead of %matplotlib inline, you will have to do something like this in your script:

from IPython import get_ipython
get_ipython().run_line_magic('matplotlib', 'inline')

A similar approach is described in this answer, but it uses the deprecated magic function.

Note that the script still needs to run in IPython. Under vanilla Python the get_ipython function returns None and get_ipython().run_line_magic will raise an AttributeError.

How to set the UITableView Section title programmatically (iPhone/iPad)?

If you are writing code in Swift it would look as an example like this

func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String?
    switch section
        case 0:
            return "Apple Devices"
        case 1:
            return "Samsung Devices"
            return "Other Devices"

Nuget connection attempt failed "Unable to load the service index for source"

In my case, I just restarted the docker and just worked.

GROUP BY without aggregate function

That's how GROUP BY works. It takes several rows and turns them into one row. Because of this, it has to know what to do with all the combined rows where there have different values for some columns (fields). This is why you have two options for every field you want to SELECT : Either include it in the GROUP BY clause, or use it in an aggregate function so the system knows how you want to combine the field.

For example, let's say you have this table:

Name | OrderNumber
John | 1
John | 2

If you say GROUP BY Name, how will it know which OrderNumber to show in the result? So you either include OrderNumber in group by, which will result in these two rows. Or, you use an aggregate function to show how to handle the OrderNumbers. For example, MAX(OrderNumber), which means the result is John | 2 or SUM(OrderNumber) which means the result is John | 3.

How do you delete all text above a certain line


delete all lines above the current one.


We had the same problem on a CentOS7 machine. Disabling the VERIFYHOST VERIFYPEER did not solve the problem, we did not have the cURL error anymore but the response still was invalid. Doing a wget to the same link as the cURL was doing also resulted in a certificate error.

-> Our solution also was to reboot the VPS, this solved it and we were able to complete the request again.

For us this seemed to be a memory corruption problem. Rebooting the VPS reloaded the libary in the memory again and now it works. So if the above solution from @clover does not work try to reboot your machine.

extract the date part from DateTime in C#

you can use a formatstring

DateTime time = DateTime.Now;              
String format = "MMM ddd d HH:mm yyyy";     

android activity has leaked window$decorview Issue

Thank you Guys to give me many suggestions. Finally I got a solution. That is i have started the NetErrorPage intent two times. One time, i have checked the net connection availability and started the intent in page started event. second time, if the page has error, then i have started the intent in OnReceivedError event. So the first time dialog is not closed, before that the second dialog is called. So that i got a error.

Reason for the Error: I have called the showInfoMessageDialog method two times before closing the first one.

Now I have removed the second call and Cleared error :-).

How to store an output of shell script to a variable in Unix?

You need to start the script with a preceding dot, this will put the exported variables in the current environment.

export output="SUCCESS"

Then execute it like so

chmod +x /tmp/
. /tmp/

When you need the entire output and not just a single value, just put the output in a variable like the other answers indicate

Error :The remote server returned an error: (401) Unauthorized

I add credentials for HttpWebRequest.

myReq.UseDefaultCredentials = true;
myReq.PreAuthenticate = true;
myReq.Credentials = CredentialCache.DefaultCredentials;

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

It is simple use below codes.

final Date todayDate = new Date();


System.out.println(new SimpleDateFormat("MM-dd-yyyy").format(todayDate));

System.out.println(new SimpleDateFormat("yyyy-MM-dd").format(todayDate));


Remove border from buttons


padding: 0;
border: none;
background: none;

to your buttons.