Question

Is it possible to get a value from the external CSS of a page if the element that the style refers to has not been generated yet? (the element is to be generated dynamically).

The jQuery method I’ve seen is $('element').css('property');, but this relies on element being on the page. Is there a way of finding out what the property is set to within the CSS rather than the computed style of an element?

Will I have to do something ugly like add a hidden copy of the element to my page so that I can access its style attributes?

Answer 1

With jQuery:

// Scoping function just to avoid creating a global
(function() {
    var $p = $("<p></p>").hide().appendTo("body");
    console.log($p.css("color"));
    $p.remove();
})();

p {color: blue}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Using the DOM directly:

// Scoping function just to avoid creating a global
(function() {
    var p = document.createElement('p');
    document.body.appendChild(p);
    console.log(getComputedStyle(p).color);
    document.body.removeChild(p);
})();

p {color: blue}

Note: In both cases, if you’re loading external style sheets, you’ll want to wait for them to load in order to see their effect on the element. Neither jQuery’s ready nor the DOM’s DOMContentLoaded event does that, you’d have to ensure it by watching for them to load.