Javascript call function from an external domain iframe

Question

Page A and page B are on different domains.

A is iframed on page B.

I need to call a function which is on page B from page A.

Is this possible without something like porthole?

Basically what I'm trying to do is a simple push notification (A notifies B), don't need to transfer any content.

Well sort of. I have full control of A, and I can convince owner of B to put a function/script on his page. — Chad, Aug 21 '11 at 06:23
Well, you might be able to use this: [window.postMessage](https://developer.mozilla.org/en/DOM/window.postMessage). (Note: it's a rather new API) — Digital Plane, Aug 21 '11 at 06:25
Mostly IE7 and below. It works with FF3+, IE8+, Chrome, Safari 5, Opera 10+ (see [this question](http://stackoverflow.com/questions/6036418/what-browsers-support-the-window-postmessage-call-now)) — Digital Plane, Aug 21 '11 at 06:32

score 1 · Answer 1 · answered Aug 21 '11 at 06:39

1

There is an HTML5 way to do this with cross window messaging.

There are various work-arounds when HTML5 isn't available that can be used even between different origins.

answered Aug 21 '11 at 06:39

jfriend00

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score 0 · Answer 2 · answered Aug 21 '11 at 06:29

If you want to avoid using that specific library you could use the concept it's based off of and roll your own. Here's a pretty in depth article that describes the technique without the use of a library: http://softwareas.com/cross-domain-communication-with-iframes.

score 0 · Answer 3 · answered Aug 21 '11 at 06:38

Put A and B with the same domain, different subdomain is fine. Then in the iframe A, you can call parent.function_name (parameter1, parameter 2). If you need to call that function very often, you may want to do this :

function p(data, div_id){parent.p(data, div_id);}

then in iframe A, you can just call p(data, div_id), which will actually call page B's function. I have used this a lot of comet streaming. If you are interested, you may read this, which basically use iframe to communicate with data:

http://www.shanison.com/2010/05/10/stop-the-browser-“throbber-of-doom”-while-loading-comet-forever-iframe/

subdomain solution is not an option. – Chad Aug 21 '11 at 06:54 — Chad, Aug 21 '11 at 06:54
Is there any reason not to just do "var p = parent.p;"? – Mörre Aug 21 '11 at 06:55 — Mörre, Aug 21 '11 at 06:55

Javascript call function from an external domain iframe

3 Answers3