How do I get a computed style?

Profile picture for Piotr Kula
Piotr Kula

Can anybody please help me with a script.. or a way to get the value of

height : 1196px;
width: 284px;

from the computed style sheet (webkit). I know IE is different- as usual. I cannot access the iframe (cross domain)—I just need the height/width.

Screenshot of what I need (circled in red). How do I access those properties?

enter image description here

Source

<iframe id="frameId" src="anotherdomain\brsstart.htm">
 <html id="brshtml" xmlns="http://www.w3.org/1999/xhtml">   
    \--I WANT THIS ELEMENTS COMPUTED BROWSER CSS HEIGHT/WIDTH

<head>
<title>Untitled Page</title>
</head>

<body>
 BLA BLA BLA STUFF

</body>

</html>
   \--- $('#frameId').context.lastChild.currentStyle 
        *This gets the actual original style set on the other domain which is "auto"
        *Now how to getComputed Style?

   
</iframe>

The closest I got is this

$('#frameId').context.lastChild.currentStyle

That gives me the actual style on the HTML element which is "auto" and that is true as thats what's its set on the iframed document.

How do I get the computed style that all the browsers use to calculate the scroll bars, and inspect elements values?

Using Tomalaks answer I conjured up this lovely piece of script for webkit

window.getComputedStyle(document.getElementById("frameId"), null).getPropertyValue("height")

or

window.getComputedStyle(document.getElementById("frameId"), null).getPropertyCSSValue("height").cssText

Result 150px

Identical to

$('#frameId').height();

So I got them to add a id of 'brshtml' to the head- maybe it will help me select the element easier. Webkit inspection shows me now html#brshtml but I cant select it using getelementbyid

If you're already using jQuery, you can use CSS to get the computed /current for any style property in any browser.

<!-- language: lang-js --> 
$("#el").css("display")
<!-- begin snippet: js hide: true console: true babel: false --> <!-- language: lang-js --> 
var $el = $("#el");

console.log(".css('display'): " + $el.css("display"))

var el = document.getElementById("el");
el.currentStyle = el.currentStyle || el.style

console.log("style.display: " + el.style.display)
console.log("currentStyle.display: " + el.currentStyle.display)
console.log("window.getComputedStyle: " + window.getComputedStyle(el).display)
<!-- language: lang-html --> 
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div id="el">element</div>
<!-- end snippet -->