Get all items that start with class name - javascript

I'm trying to only show certain divs. The way I have decided to do this is to first hide all elements that start with "page" and then only show the correct divs. Here's my (simplified) code:
<form>
<input type="text" onfocus="showfields(1);">
<input type="text" onfocus="showfields(2);">
</form>
<div class="page1 row">Some content</div>
<div class="page1 row">Some content</div>
<div class="page2 row">Some content</div>
<div class="page2 row">Some content</div>
<script>
function showfields(page){
//hide all items that have a class starting with page*
var patt1 = /^page/;
var items = document.getElementsByClassName(patt1);
console.log(items);
for(var i = 0; i < items.length; i++){
items[i].style.display = "none";
}
//now show all items that have class 'page'+page
var item = document.getElementsByClassName('page' + page);
item.style.display = '';
}
</script>
When I console.log(items); I get a blank array. I'm pretty sure the regexp is right (get all items starting with 'page').
The code I'm using is old school JS, but I'm not adverse to using jQuery. Also if there is a solution that doesn't use regexp, that's fine too as I'm new to using regexp's.

getElementsByClassName only matches on classes, not bits of classes. You can't pass a regular expression to it (well, you can, but it will be type converted to a string, which is unhelpful).
The best approach is to use multiple classes…
<div class="page page1">
i.e. This div is a page, it is also a page1.
Then you can simply document.getElementsByClassName('page').
Failing that, you can look to querySelector and a substring matching attribute selector:
document.querySelectorAll("[class^=page]")
… but that will only work if pageSomething is the first listed class name in the class attribute.
document.querySelectorAll("[class*=page]")
… but that will match class attributes which mention "page" and not just those with classes which start with "page" (i.e. it will match class="not-page".
That said, you could use the last approach and then loop over .classList to confirm if the element should match.
var potentials = document.querySelectorAll("[class*=page]");
console.log(potentials.length);
elementLoop:
for (var i = 0; i < potentials.length; i++) {
var potential = potentials[i];
console.log(potential);
classLoop:
for (var j = 0; j < potential.classList.length; j++) {
if (potential.classList[j].match(/^page/)) {
console.log("yes");
potential.style.background = "green";
continue elementLoop;
}
}
console.log("no");
potential.style.background = "red";
}
<div class="page">Yes</div>
<div class="notpage">No</div>
<div class="some page">Yes</div>
<div class="pageXXX">Yes</div>
<div class="page1">Yes</div>
<div class="some">Unmatched entirely</div>

Previous answers contain parts of the correct one, but none really gives it.
To do this, you need to combine two selectors in a single query, using the comma , separator.
The first part would be [class^="page"], which will find all the elements whose class attribute begins with page, this selector is thus not viable for elements with multiple classes, but this can be fixed by [class*=" page"] which will find all the elements whose class attribute have somewhere the string " page" (note the space at the beginning).
By combining both selectors, we have our classStartsWith selector:
document.querySelectorAll('[class^="page"],[class*=" page"]')
.forEach(el => el.style.backgroundColor = "green");
<div class="page">Yes</div>
<div class="notpage">No</div>
<div class="some page">Yes</div>
<div class="pageXXX">Yes</div>
<div class="page1">Yes</div>
<div class="some">Unmatched entirely</div>

You can use jQuery solution..
var $divs = $('div[class^="page"]');
This will get all the divs which start with classname page

$(document).ready(function () {
$("[class^=page]").show();
$("[class^=page]").hide();
});
Use this to show hide div's with specific css class it will show/hide all div's with css class mention.

Related

Javascript - Strip certain strings from ".innerHTML" result

I have a function that's run on a button click. This function will get all of the HTML inside a certain element. That works fine. However, I would like to clean the returned string (HTML) up before using it further in my function:
exportHTML(){
const element = document.getElementById('content');
const innerHTML = element.innerHTML;
}
This works. But due to using Angular, Angular syntax is included within the HTML based on conditions in the source code. For example:
<div _ngcontent-c1=""></div>
OR
<div ng-reflect-klass="panel album"></div>
<div ng-reflect-ng-class="blue"></div>
Is it at all possible to filter these types of values out? In regards to the second and third example above, the classes within those would change quite often:
Is it possible to filter out and remove all _ngcontent-c1="" text
Is it possible to filter out and remove all ng-reflect-klass & ng-reflect-ng-class including the following open and closed quotes (to remove what's inside)
OK, so the attributes would be constant but the values of the attributes would change? If so, you could try this:
.replace(/ng-reflect-klass=\".?\"/,"").replace(/ng-reflect-ng-class=\".?\"/,"").replace(/_ngcontent-c1=\".*?\"/,"")
var content = 'stuff<div ng-reflect-klass="panel album"></div><div ng-reflect-ng-class="blue"></div><div _ngcontent-c1=""></div>end stuff';
console.log(content.replace(/ng-reflect-klass=\".*?\"/g,"").replace(/ng-reflect-ng-class=\".*?\"/g,"").replace(/_ngcontent-c1=\".*?\"/g,""));
Look at the console to view the result.
You could do it with RegExp
const innerHTML = element.innerHTML.replace(/ (_ngcon|ng-).*?".*?"/g, '');
(_ngcon|ng-) find _ngcon or ng- including space as first character
.*?" match everything until first "
.*?" and match everything again for the closing "
I created a JSFiddle as an example of how to do this without using jQuery.
Using the HTML code below as an example
<div id="origin-content">
<div id="div1" _ngcontent-c1="">Content 1</div>
<div id="div2" ng-reflect-klass="panel album">Content 2</div>
<div id="div3" ng-reflect-ng-class="blue">Content 3</div>
</div>
<hr>
<div id="target-content">
</div>
I extracted all children from origin-content and copied them to target-content using the code that follows.
var result = document.getElementById('target-content');
var elems = document.querySelector('#origin-content').children;
var count = elems.length;
for (var i = 0; i < count; i++) {
var val = elems[i];
val.removeAttribute('_ngcontent-c1');
val.removeAttribute('ng-reflect-klass');
val.removeAttribute('ng-reflect-ng-class');
result.innerHTML += val.outerHTML;
}
There is still plenty of room for improvement.
I hope it helps to solve the OP question.
The following solution will remove all the attributes from element:
You can get all the children first. Then loop through them with forEach(). In each iteration, you can use while loop to removeAttribute() until they are exist in the element.
Try the following way:
function exportHTML(){
const element = document.getElementById('content');
const innerHTML = [].slice.call(element.children);
innerHTML.forEach(function(el){
while(el.attributes.length > 0)
el.removeAttribute(el.attributes[0].name);
});
console.log(document.getElementById('content').innerHTML); // output
}
exportHTML();
<div id="content">
<div _ngcontent-c1=""></div>
<div ng-reflect-klass="panel album"></div>
<div ng-reflect-ng-class="blue" another-test></div>
<span test="test-element"></span>
</div>

div#d1 toggle on p#1 click - howTo?

I am trying to toggle a div when its name is clicked.
I have multiple coupls like that in my page, and I want it to work as
"when <p id= "d2"> is clicked => <div id="d2"> is toggled".
I tried those functions:
$(document).ready(function(){
$("p").click(function(){
$("div#" + $(this).attr('id')).toggle();
});
});
function rgt() {
//document.body.innerHTML = "";
var id = "d" + this.id;
var situation = document.getElementById(id).style.display;
if (situation == "none") {
situation = "block";
}
else {
situation = "none";
}
}
function showHide(theId) {
if (document.getElementById("d" + theId).style.display == "none") {
document.getElementById("d" + theId).style.display = "block";
}
else {
document.getElementById("d" + theId).style.display = "none";
}
}
I can't make it Work!!! Why is it?
the browser says:"no 'display' property for null"...
I will be more than happy to solve it with simple jquery
Ensure Your id Attributes Are Unique
Assuming that your id attributes are unique, which they are required to be per the specification:
The id attribute specifies its element's unique identifier (ID). The
value must be unique amongst all the IDs in the element's home subtree
and must contain at least one character. The value must not contain
any space characters.
You should consider renaming your id attributes to d{n} and your paragraphs to p{n} respectively as seen below :
<button id='p1'>p1</button> <button id='p2'>p2</button> <button id='p3'>p3</button>
<div id='d1'><pre>d1</pre></div>
<div id='d2'><pre>d2</pre></div>
<div id='d3'><pre>d3</pre></div>
which would allow you to use the following function to handle your toggle operations :
$(function(){
// When an ID that starts with P is clicked
$('[id^="p"]').click(function(){
// Get the proper number for it
var id = parseInt($(this).attr('id').replace(/\D/g,''));
// Now that you have the ID, use it to toggle the appropriate <div>
$('#d' + id).toggle();
})
});
Example Using Unique IDs
You can see an interactive example of this approach here and demonstrated below :
Consider Using data-* Attributes
HTML supports the use of data attributes that can be useful for targeting specific elements through jQuery and associating them to other actions. For instance, if you create an attribute on each of your "p" elements as follows :
<button data-toggles='d1'>p1</button>
<button data-toggles='d2'>p2</button>
<button data-toggles='d3'>p3</button>
and then simply change your jQuery to use those as selectors :
$(function(){
// When an element with a "toggles" attribute is clicked
$('[data-toggles]').click(function(){
// Then toggle its target
$('#' + $(this).data('toggles')).toggle();
});
});
Is this you are looking?
$("#p1").on("click", function() {
$("#d1").toggle();
});
js fiddle: https://jsfiddle.net/Jomet/09yehw9y/
jQuery(function($){
var $toggles = $('.divToggle');
var $togglables = $('.togglableDiv');
$toggles.on('click', function(){
//get the div at the same index as the p, and toggle it
$togglables.eq($toggles.index(this)).toggle();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<p class="divToggle">Show Me 1</p>
<p class="divToggle">Show Me 2</p>
<p class="divToggle">Show Me 3</p>
<div class="togglableDiv">Weeee 1</div>
<div class="togglableDiv">Weeee 2</div>
<div class="togglableDiv">Weeee 3</div>
Minimal approach using classes. This solution assumes the order of the p elements in the dom are in the same order as the divs are in the order. They do not have to be contiguous, but the order does matter with this solution.
ids are not the droids you are looking for.
An id needs to be unique. If you want to classify something one would suggest to use classes. You can actually use serveral of them for some fancy stuff. How about something like this:
<p class="toggle one">one</p>
<div class="toggle one" style="display:none">content one</div>
Straight forward. Every element that is a switch or switchable gets the class toggle. Each pair of switch and switchable(s) gets an additional identifier (like one, two, ...).
Simple JScript Implementation:
Now how about not using JQuery to work with that? Sure it i$ handy, but it hides all that neat stuff one would eventually like to learn her/himself!
var myToggle = {};
(function(module) {
"use strict";
(function init() {
var elements = document.getElementsByClassName("toggle");
var element;
var i = elements.length;
while (i) {
i -= 1;
element = elements[i].className;
elements[i].setAttribute("onclick", "myToggle.swap(\"" + element + "\")");
}
}());
module.swap = function(element) {
var couple = document.getElementsByClassName(element);
var i = couple.length;
while (i) {
i -= 1;
if (couple[i].style.display === "none" && couple[i].tagName === "DIV") {
couple[i].style.display = "block";
} else if (couple[i].tagName === "DIV") {
couple[i].style.display = "none";
}
}
};
}(myToggle));
<p class="toggle one">one</p>
<div class="toggle one" style="display:none">content one</div>
<p class="toggle two">two</p>
<div class="toggle two" style="display:none">content two 1</div>
<div class="toggle two" style="display:none">content two 2</div>
var myToggle = {} is the object we use to keep our little program contained. It prevents that our code conflicts with other declarations. Because what if some plugin on our site already declared a function called swap()? One would overwrite the other!
Using an object like this ensures that our version is now known as myToggle.swap()!
It may be hard to follow how it got to that name. Important hint: something looking like this... (function() { CODE } ()) ...is called an immediately-invoked function expression. iffy! It's a function that is immediatly executed and keeps its variables to itself. Or can give them to whatever you feed it in the last ()-pair.
Everything else is as verbose as can be... no fancy regular expressions, hacks or libraries. Get into it!

How can I count how many divs whose ids begin with a certain text that are inside a div using JQuery?

Here's the html:
<div class="col-sm-12" id="ProdutosPedido">
<div class="row">
<div class="col-sm-12 formProdutoAdd" id="produto_1">
...
</div>
</div>
</div>
As things happen within the page, divs are appended inside #ProdutosPedido, and #produto_1 increments to #produto_2 and so on.
This is not working for me:
console.log($("#ProdutosPedido > [id^=produto_]").length);
I need to iterate over these "produto_" and use the 'i' to refer to the current div, but I don't know how to do it. My example logs 0, and that should not be the case, since it starts with 1.
Since your produto divs are not direct children of ProdutosPedido, but its descendants, you need to use the following selector:
$("#ProdutosPedido [id^=produto_]")
Here is the working JSFiddle demo.
Pure Javascript Solution
function CountDiv() {
var nodes = document.getElementById('ProdutosPedido').getElementsByTagName('*');
var Count = 0;
for (var i = 0; i < nodes.length; i++) {
if (nodes[i].id.substring(0, 8) == 'produto_')
Count++;
}
alert(Count);
}

getElementById with changing IDs

I need to hide all the elements that have the string "replies-36965584" anywhere in their IDs.
HTML:
<div id="replies-36965584_1">aaaa</div>
<div id="replies-36965584_2">aaaa</div>
<div id="replies-36965584_3">aaaa</div>
<div id="replies-36965584_4">aaaa</div>
<div id="replies-36222224_2">nnnn</div>
JavaScript:
document.getElementById("replies-36965584").style.display="none"
How can I modify this JS to select the first four elements?
You can do this with CSS and attribute selectors.
[att^=val]
Represents an element with the att attribute whose value begins with the prefix "val". If "val" is the empty string then the selector does not represent anything.
Source: http://www.w3.org/TR/css3-selectors/#attribute-substrings
jsfiddle
CSS
[id^="replies-36965584_"] {
display: none;
}
Is using jQuery an option? If so, this is dead simple:
$(document).ready(function(){
$('div[id^="replies-36965584"]').hide();
});
If you're unfamiliar with jQuery, here's a link to get started: http://learn.jquery.com/javascript-101/getting-started/
EDIT: Fixed syntax error.
EDIT: Added jsFiddle: http://jsfiddle.net/xbVp9/
If you don't know certain literal values but you know the general pattern and only the number will change, then I will consider some matching with regular expresiion.
You can do it the painful way:
var o = document.getElementsByTagName("div");
for (var i=0;i<o.length;i++) {
if(o[i].id.indexOf('replies-36965584') == 0) {
o[i].style.display = 'none';
}
}
The only way to do this with vanilla javascript that I know of, is to fetch all the divs on the page, and test the id's for the ones you want.
var divs = document.getElementsByTagName('div');
for (var i = 0; i < divs.length; ++i) {
var div = divs[i];
if (/replies-36965584/.test(div.id)) {
div.style.display = 'none';
}
}

Calculate the number of html element with js

I have multiple div elements with same id='mydiv'.I want to calculate these divs and Iam using the code
document.getElementById('mydiv').length
But it is not working
What you should do is use class instead of ID's. ID is for one element only, class is for multiple.
http://jsfiddle.net/d7AHV/
It won't work as getElementById will always return an element with the specified ID and null if the specified ID doesn't exist
From ECMA
getElementById(elementId) This method returns a Element. The elementId
parameter is of type DOMString.
What you can do is to assign each div with class
<div class="mydiv"></div>
<div class="mydiv"></div>
<div class="mydiv"></div>
<div class="mydiv"></div>
<div class="mydiv"></div>​​​​​​​​​
And iterate over:
var divs = document.getElementsByTagName('div');
var count = 0;
for(var i = 0; i < divs.length; i++) {
if(divs[i].className == 'mydiv') count++;
}
alert(count);
If your clients support document.getElementsByClassName(), it's even more concise:
alert(document.getElementsByClassName('mydiv').length)
You've been told about multiple elements with the same ID, but in rare cases it might be unavoidable (e.g. an XML document over which you have no control). The only adverse behaviour is that selecting by ID will usually only return the first one (but that's not guaranteed).
You can count elements with the same id by looping over all the elements in the document and counting the ones with a matching id, e.g.
function countSameIds(id) {
var allNodes = document.getElementsByTagName('*');
for (var i=allNodes.length, count=0; i; ) {
if (allNodes[--i].id == id) {
++count;
}
}
return count;
}

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