How to get child element by ID in JavaScript? - javascript

I have following html:
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
How can I get textarea element? I can't use document.getElementById("textid") for it
I'm doing it like this now:
var note = document.getElementById("note");
var notetext = note.querySelector('#textid');
but it doesn't work in IE(8)
How else I can do it? jQuery is ok
Thanks

If jQuery is okay, you can use find(). It's basically equivalent to the way you are doing it right now.
$('#note').find('#textid');
You can also use jQuery selectors to basically achieve the same thing:
$('#note #textid');
Using these methods to get something that already has an ID is kind of strange, but I'm supplying these assuming it's not really how you plan on using it.
On a side note, you should know ID's should be unique in your webpage. If you plan on having multiple elements with the same "ID" consider using a specific class name.
Update 2020.03.10
It's a breeze to use native JS for this:
document.querySelector('#note #textid');
If you want to first find #note then #textid you have to check the first querySelector result. If it fails to match, chaining is no longer possible :(
var parent = document.querySelector('#note');
var child = parent ? parent.querySelector('#textid') : null;

Here is a pure JavaScript solution (without jQuery)
var _Utils = function ()
{
this.findChildById = function (element, childID, isSearchInnerDescendant) // isSearchInnerDescendant <= true for search in inner childern
{
var retElement = null;
var lstChildren = isSearchInnerDescendant ? Utils.getAllDescendant(element) : element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].id == childID)
{
retElement = lstChildren[i];
break;
}
}
return retElement;
}
this.getAllDescendant = function (element, lstChildrenNodes)
{
lstChildrenNodes = lstChildrenNodes ? lstChildrenNodes : [];
var lstChildren = element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].nodeType == 1) // 1 is 'ELEMENT_NODE'
{
lstChildrenNodes.push(lstChildren[i]);
lstChildrenNodes = Utils.getAllDescendant(lstChildren[i], lstChildrenNodes);
}
}
return lstChildrenNodes;
}
}
var Utils = new _Utils;
Example of use:
var myDiv = document.createElement("div");
myDiv.innerHTML = "<table id='tableToolbar'>" +
"<tr>" +
"<td>" +
"<div id='divIdToSearch'>" +
"</div>" +
"</td>" +
"</tr>" +
"</table>";
var divToSearch = Utils.findChildById(myDiv, "divIdToSearch", true);

(Dwell in atom)
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
<script type="text/javascript">
var note = document.getElementById('textid').value;
alert(note);
</script>

Using jQuery
$('#note textarea');
or just
$('#textid');

$(selectedDOM).find();
function looking for all dom objects inside the selected DOM.
i.e.
<div id="mainDiv">
<p>Paragraph 1</p>
<p>Paragraph 2</p>
<div id="innerDiv">
link
<p>Paragraph 3</p>
</div>
</div>
here if you write;
$("#mainDiv").find("p");
you will get tree p elements together. On the other side,
$("#mainDiv").children("p");
Function searching in the just children DOMs of the selected DOM object. So, by this code you will get just paragraph 1 and paragraph 2. It is so beneficial to prevent browser doing unnecessary progress.

Related

Parse html string and delete some elements

I have a html string and I need to remove all between first occurrence of <div class="c and first close tag > and last closing tag "</div>". The first, should be this because it class is dynamically generated.
For example: <div class="c2029" style="font-size:45px"><p class="auto">Testing 123...</p></div> should be transformed to <p class="auto">Testing 123...</p>
I tried this, but it's removing all string:
var testString = '<div class="c2029" style="font-size:45px"><p class="auto">Testing 123...</p></div>'
var result = testString.replace(/\<div\_c.*\>/, '');
The content into div that should be removed is dynamically generated, it is an example.
More examples of dynamic string generated:
var testString = '<div class="c03"><div style="text-align: center">Testing 123...</div></div>';
var testString = '<div class="c435">Hello</div>';
var testString = '<div class="c1980">TEST</div>';
No need to use regular expressions, you can achieve this with jQuery's $.fn.unwrap:
$('[class^="c"]').children().unwrap()
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="c2029" style="font-size:45px">
<p class="auto">Testing 123...</p>
</div>
To make it more bullet proof and target only element with class staring with "c" and with numbers after you could add additional filtering step:
$('[class^="c"]').filter(function () {
return this.className.match(/\bc\d+\b/)
}).children().unwrap()
This way it will not affect classes like cello (starts with "c").
Regex is wrong tool for this. You can just $.parseHTML() and then find() using [name^=”value”] selector and use it:
var all = ['<div><div class="c2029" style="font-size:45px"><p class="auto">Testing 123...</p></div></div>', '<div><div class="c435">Hello</div></div>', '<div><div class="c1980">TEST</div></div>'];
$.each(all, function(k,s) { f(s); });
function f(s) {
var nodes = $($.parseHTML(s)); // parse string to jquery object
var $p = nodes.find('div[class^="c"]'); // select all classes that starts with c
var inner = $p.prop('innerHTML'); // inner html of $p
console.log("Inner: " + inner);
$p.html(''); // select children of $p and remove
var outer = $p.prop('outerHTML'); // outer html of $p
console.log("Outer: " + outer);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Based on Stack Overflow answers, I found this solution that resolve my problem:
var testString = '<div class="c2029" style="font-size:45px"><p class="auto">Testing 123...</p></div>'
var result = testString.replace(/<div class="c.*?>(.*?)<\/div>/, '$1');
document.write(result);
console.log(result);

Remove all HTML <button> elements with regex

I'm trying to build a program to run a function every time I press a button, and output the returned value. To do this, I use the following HTML:
<h2>Test Results:</h2>
<strong><span id='runs'>0</span> tests</strong><br>
<div id='testResults'>
<button id='test' onClick='this.parentNode.innerHTML = initiatePlanB()'>Begin</button>
</div>
Here's the javascript:
var tests = document.getElementById('runs');
var inner = document.getElementById('testResults').innerHTML;
//Here's the part I can't figure out
var wo = inner.replace(??????, '');
var out = wo + '<br><strong>Test #' + String(Number(tests.innerText) + 1) + '</strong><br>';
tests.innerText = Number(tests.innerText) + 1;
//More stuff here
return out;
Basically, I need either a regex expression, or some other function that can remove any html tag and it's contents.
Why not just find all buttons using getElementsByTagName('button')
and then remove them all?
var testCount = 0;
var tests = document.getElementById('runs');
var inner = document.getElementById('testResults')
function initiatePlanB() {
var buttons = inner.getElementsByTagName('button');
if (buttons) {
for (var i = 0; i < buttons.length; i++) {
buttons[i].remove();
}
}
testCount++;
inner.insertAdjacentHTML('beforeend', '<br><strong>Test #' + testCount + '</strong><br>');
tests.innerText = testCount;
//More stuff here
}
<h2>Test Results:</h2>
<strong><span id='runs'>0</span> tests</strong><br>
<div id='testResults'>
<button id='test' onClick='initiatePlanB()'>Begin</button>
</div>
Though you should probably just hide the buttons, or disable them.

How could I add the same string on different paragraph multiple time on the same HTML page?

I wish to know the best way to write only once the same thing and repeat inside the same page. For example:
<div>
<p id="description1"></p>
</div>
<div>
<p id="description1"></p>
</div>
--
I wish to write only one time the description1 inside the body. I think this could be achieved using the DOM.
Put the elements in the same class using the class attribute, then get the list of all elements using the getElementsByClassName() DOM function. You can then go over the list using a for loop.
[].forEach.call(document.getElementsByClassName("description"), function(elem) {
elem.innerHTML = "StackOverflow saved my day!";
});
You can even put the text in all elements of the same class using no JavaScript and only CSS by using the content attribute.
First of all, the ID field should be unique per element.
If you give all the tags a class <p class="description"></p> then you can use jQuery to set them all by calling:
$('.description').text('This is the text')
In javascript:
var elements = document.getElementsByClassName("description");
for (var i = 0; i < elements.length; i++) {
elements[i].innerHTML = "This is the text.";
}
Have a look at the solutions proposed here
How to repeat div using jQuery or JavaScript?
this one seems to work pretty well:
html:
<div id="container">data</div>
js:
var container = document.getElementById('container');
function block(mClass, html) {
//extra html you want to store.
return '<div class="' + mClass + '">' + html + '</div>';
}
// code that loops and makes the blocks.
// first part: creates var i
// second: condition, if 'i' is still smaller than three, then loop.
// third part: increment i by 1;
for (var i = 0; i < 3; i++) {
// append the result of function 'block()' to the innerHTML
// of the container.
container.innerHTML += block('block', 'data');
}
JSFIDDLE
Just added with a code by using
getElementsByClassName()
`<html>
<body>
<div class="example">First div element with class="example".</div>
<p class="example">Second paragraph element with class="example".</p>
<p>Click the button to change the text of the first div element with class="example" (index 0).</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.</p>
<script>
function myFunction() {
var x = document.getElementsByClassName("example");
for(var i=0;i< x.length;i++)
x[i].innerHTML = "Hello World!";
}
</script>
</body>
</html>`
If you wish to keep id, change your code like this :
script :
var pcount = 2// # p
var desc = document.getElementById('description1');
for(i=0; i<pcount;i++){
document.getElementById('description' + i).innerHTML = desc;
}
html
<div>
<p id="description1"></p>
</div>
<div>
<p id="description2"></p>
</div>
two elements cannot have same id but can have same class
<head>
<script>
var x = document.getElementsByClassName("description");
for (var i = 0; i < x.length; i++) {
x[i].innerHTML = "This is the text.";
}
</script>
<style>
.description1 { // this will apply the same style to all elements having class as description1
text-align: center;
color: red;
}
</style>
</head>
<body>
<div>
<p class="description1"></p>
</div>
<div>
<p class="description1"></p>
</div>
</body>
See the script tag. this solves your problem

Call By Reference error in javascript(edited)

just try to run this code in two ways:
1) run this code below;
2) enable for loop then run it
<html>
<head>
<script>
function toggle(){
//console.log('hi');
var samplediv = document.getElementById('samplediv');
samplediv.innerHTML = '';
var i = 1;
//for(var i = 0; i < 3; ++i){
samplediv.innerHTML +=
"<div id=\'jh"+ i + "\'>Hi This is "+i+"</div>" +
"<div id=\'edit" + i + "\' style=\'display:none\'>Edit "+i+"</div>" ;
document.getElementById('jh'+i).addEventListener("click", function(){document.getElementById('edit'+i).style.display="block";});
/*
(function(i){
//console.clear();
var key = i;
i += "";
document.getElementById('jh0').addEventListener("click", function(){document.getElementById('edit0').style.display="block";});
//document.getElementById('jh'+key).addEventListener("click", function(){document.getElementById('edit'+key).style.display="none";}, true);
//console.log(i, key);
}(i));
*/
//}
}
</script>
</head>
<body>
<div id="samplediv" >over here</div>
<script>toggle();</script>
</body>
</html>
I'm trying to add addEventLister on every divs using for. I'm sure this is kind of call by reference error. I know there are ways to add events such as on attribute method. Also adding a number of similar listeners is inefficient but I have to make them as you can see.
I've made a IIFE to make key be a value but failed. Do you have any idea to solve this problem?(No jQuery please)
JSFiddle
You will change method which You use to adding new elements.
I replaced innerHTML += to document.createElement for each new item.
var jh = document.createElement('div');
jh.id = 'jh'+i;
jh.innerText = 'Hi This is '+i;
var edit = document.createElement('div');
edit.id = 'edit'+i;
edit.style.display = 'none';
edit.innerText = 'Edit '+i;
samplediv.appendChild(jh).appendChild(edit);
Variable i on click event is visible with last value, so You must get index from other source (from id for example).
document.getElementById('jh'+i).addEventListener("click", function(){
var jhIndex = this.id.split('jh')[1];
document.getElementById('edit'+jhIndex).style.display= 'block';
});

Appending a block of CSS upon submit

http://jsfiddle.net/rfnslyr/CRqXm/1/
I have the following fiddle which extracts CSS classes and ID's, and posts them to console. I want to type a name into the top box, paste some code, and have it generate a separate set of unique css ID's and classes into a new instance of the #classes instance (which has uin0CE + a bunch of classes in it).
I have that posting to console done, I just don't know how to "spawn" a new instance of the the #classes section on submit every time I add a new name to #codeName and code to #codeInput.
index.html
<div id="container">
<input id="codeName" class="boxsizingBorder"></input><br>
<textarea id="codeInput" class="boxsizingBorder"></textarea><br>
<button id="submitCode">submit</button>
<div id="classes">
<div class="pageTitle">uin0CE</div>
<div class="cssClassesIDs">
ui-icon-nodisc,redDotClass,translate,test,ui-hide-label,ui-grid-a,ui-block-a,ui-block-b,alignRight,ui-grid-solo,ui-disabled,companyFieldset,longbutton,icon-map-marker,locationIcon,icon-phone,contactIcon,legalBlock,legal,legalDivider,signInInfoIcon,icon-info-sign,ui-icon-alt
</div>
</div>
</div>
<script src="functions.js"></script>
functions.js
$(function() {
$('#submitCode').click(function() {
var CSS_CLASSES = [];
var CSS_IDS = [];
var el = document.createElement( 'div' );
var text = $("#codeInput").val();
el.innerHTML = text;
var nodes = el.getElementsByTagName('*');
for (var i = 0; i < nodes.length; i++) {
var node = nodes[i];
if (node.id.length > 0) {
CSS_IDS.push.apply(CSS_IDS, node.id.split(" "));
}
if (node.className.length > 0) {
CSS_CLASSES.push.apply(CSS_CLASSES, node.className.split(" "));
}
}
var uniqueNames = [];
$.each (CSS_CLASSES, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});
console.log(uniqueNames + " --- " + uniqueNames.length);
});
});
Edit: I added this to your fiddle:
//Added this section here
var name = $('#codeName').val();
var code = uniqueNames;
$('#classes').empty();
$('#classes').append('<div class="pageTitle">'+name+'</div>');
$('#classes').append('<div class="cssClassesIDs">'+code+'</div>');
Here's the updated fiddle: http://jsfiddle.net/CRqXm/4/
I'm hoping I'm following your question correctly, but this seems to be what you're looking for.

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