Resizing an iframe based on content

Question

I am working on an iGoogle-like application. Content from other applications (on other domains) is shown using iframes.

How do I resize the iframes to fit the heigh

Answer 1

I'm implementing ConroyP's frame-in-frame solution to replace a solution based on setting document.domain, but found it to be quite hard determining the height of the iframe's content correctly in different browsers (testing with FF11, Ch17 and IE9 right now).

ConroyP uses:

var height = document.body.scrollHeight;

But that only works on the initial page load. My iframe has dynamic content and I need to resize the iframe on certain events.

What I ended up doing was using different JS properties for the different browsers.

function getDim () {
    var body = document.body,
        html = document.documentElement;

    var bc = body.clientHeight;
    var bo = body.offsetHeight;
    var bs = body.scrollHeight;
    var hc = html.clientHeight;
    var ho = html.offsetHeight;
    var hs = html.scrollHeight;

    var h = Math.max(bc, bo, bs, hc, hs, ho);

    var bd = getBrowserData();

    // Select height property to use depending on browser
    if (bd.isGecko) {
        // FF 11
        h = hc;
    } else if (bd.isChrome) {
        // CH 17
        h = hc;
    } else if (bd.isIE) {
        // IE 9
        h = bs;
    }

    return h;
}

getBrowserData() is browser detect function "inspired" by Ext Core's http://docs.sencha.com/core/source/Ext.html#method-Ext-apply

That worked well for FF and IE but then there were issues with Chrome. One of the was a timing issue, apparently it takes Chrome a while to set/detect the hight of the iframe. And then Chrome also never returned the height of the content in the iframe correctly if the iframe was higher than the content. This wouldn't work with dynamic content when the height is reduced.

To solve this I always set the iframe to a low height before detecting the content's height and then setting the iframe height to it's correct value.

function resize () {
    // Reset the iframes height to a low value.
    // Otherwise Chrome won't detect the content height of the iframe.
    setIframeHeight(150);

    // Delay getting the dimensions because Chrome needs
    // a few moments to get the correct height.
    setTimeout("getDimAndResize()", 100);
}

The code is not optimized, it's from my devel testing :)

Hope someone finds this helpful!