使用 Javascript 访问 iFrame 内的 DOM

Question

I am trying to access a DOM element from my main page and want to update the CSS. I use the following;

var myIframeContainerEl = $('#myIframeContainerEl');
myIframeContainerEl.contents().find(".required").css("color", "#f0f0f0");

This is not working for some reason. While it is able to find "myIframeContainerEl", for some reasons, "myIframeContainerEl.contents()" shows a length of 0. Is the above not the correct way of doing it?

Also, just to add, I am using this in my Ember project and use it within didTransition hook and inside "afterRender" So the element is present when I am trying to access.

Answer 1

iframe s don't have contents in the document they appear in. But they have a contentDocument property that refers to the document that they do have contents in. You can tell jQuery to look in that document like this:

var frameDocument = $('#myIframeContainerEl')[0].contentDocument;
$(frameDocument).find(".required").css("color", "#f0f0f0");

(Note that this assumes the iframe 's contents are from the same origin, otherwise the Same Origin Policy forbids access unless CORS or similar is used.)