Change the style of :before and :after pseudo-elements? [duplicate]

Question

This is what my code looks like:

$('.mainSpan:before').css('background','url(_gfx/cmn/main_bg.png)'); 

This does not seem to work so I'm asking if it's even possible to add background images to shadow elements with jQuery.

Answer 1

It's not possible to directly access pseudo-elements with Javascript as they're not part of the DOM. You can read their style using the optional second argument - which most, although not all, browsers in current use support - in .getComputedStyle() but you can't directly change their style.

However, you could change their style indirectly by adding in a new style element containing new rules. For example:

http://jsfiddle.net/sjFML/

The initial CSS assigns the :before pseudo-element with a green background, which is turned to black by inserting a new style element.

HTML:

<div id="theDiv"></div> 

CSS:

#theDiv {     height: 100px;     background: red; }  #theDiv:before {     content:' ';     display: block;     width: 50px;     height: 50px;     background: green; } 

Javascript:

var styleElem = document.head.appendChild(document.createElement("style"));  styleElem.innerHTML = "#theDiv:before {background: black;}";