The other day I had to alter the stylesheets in a child IFrame when a user selected an item from a drop-down. My first draft was pretty ugly, it ivolved getting the DOM from the child IFrame (by getting it’s contentWindow or contentDocument property) then getting the of the DOM and looping over all the child items… yuck!

I coded up this jQuery extension method which will return a jQuery-wrapped DOM instance for any of the matched IFrames.

(function($) {
    $.fn.extend({
        dom: function () {
            var $this = $(this);
            var getDom = function(o) {
                if( !o || (!o.contentWindow && !o.contentDocument) ) {
                    return null;
                }

                var doc = (o.contentWindow || o.contentDocument);

                return doc.document || doc;
            };

            var dom = getDom($this[0]);

            return dom === null ? $this : $(dom);
        }
    });
})(jQuery);

So with this, getting the styles for a child IFrame is as easy as:

$('iframe').dom().find('head link').each(function(index, item) {
    alert(item.href);
});

Unfortunately, this code will only work if your IFrame is hosting content that is on the same domain as its parent.

Javascript · jquery · jquery-extensions