How do I get a computed style?

Piotr Kula picture Piotr Kula · May 6, 2011 · Viewed 69.8k times · Source

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

Answer

Lightness Races in Orbit picture Lightness Races in Orbit · May 6, 2011

See this answer.

It's not jQuery but, in Firefox, Opera and Safari you can use window.getComputedStyle(element) to get the computed styles for an element and in IE you can use element.currentStyle. The returned objects are different in each case, and I'm not sure how well either work with elements and styles created using Javascript, but perhaps they'll be useful.

The iframe looks about 150px high to me. If its contents are 1196px high (and indeed, you appear to be exploring the html node, according to the screenshot) and that's what you want to get, then you should navigate into the DOM of the iframe's document and apply the above technique to that.