Question

How to get all DEFINED CSS Selectors for a given DOM Element using jQuery?

With defined I mean all CSS Selectors which are used in any of the Stylesheets applied to the document.

In a way, this is similar to the feature implemented by FireBug where in it shows all the Applied CSS Selectors for a selected DOM Element.

Any help is appreciated.

Answer 1

From this answer you might be able to get what you are looking for by looping through the cssRules property.

var myElement = $("#content");
for (var x = 0; x < document.styleSheets.length; x++) {
    var rules = document.styleSheets[x].cssRules;
    for (var i = 0; i < rules.length; i++) {
        if (myElement.is(rules[i].selectorText)) {
            $("ul").append("<li>" + rules[i].selectorText + "</li>");
        }
    }
}

Given the following dom:

<div>
    <div id="content">
    </div>
</div>

And css rules:

div
{
    background-color:black;
}
#content{
    height:50px;
    width:50px;
}
div > div
{
    border: solid 1px red;
}

We would get a matched rule set of:

body, div, dl, dt, dd, ul, ol, li, h1, h2, h3, h4, h5, h6, pre, form,fieldset, input, textarea, p,
blockquote, th, td div
#content 
div > div

Example on jsfiddle. Not sure how well this will work for all scenarios but might be something to look at if it will fit your needs.

Updated with a slightly more complete example…

$(document).click(function(event) {
    var rules = GetAppliedCssRules($(event.target));
    var $ul = $("#rules").empty();
    $.each(rules, function() {
        $ul.append("<li>" + this + "</li>");
    });
    event.preventDefault();
});

function GetAppliedCssRules($element) {
    var appliedRules = [];
    for (var x = 0; x < document.styleSheets.length; x++) {
        var rules = document.styleSheets[x].cssRules;
        for (var i = 0; i < rules.length; i++) {
            if ($element.is(rules[i].selectorText)) {
                appliedRules.push(rules[i].selectorText);
            }
        }
    }
    return appliedRules;
}