Get DOM content of cross-domain iframe [duplicate]
You can't. XSS protection. Cross site contents can not be read by javascript. No major browser will allow you that. I'm sorry, but this is a design flaw, you should drop the idea.
EDIT
Note that if you have editing access to the website loaded into the iframe, you can use postMessage (also see the browser compatibility)
There is a simple way.
You create an iframe which has for source something like "http://your-domain.com/index.php?url=http://the-site-you-want-to-get.com/unicorn
Then, you just get this url with
$_GETand display the contents withfile_get_contents($_GET['url']);
You will obtain an iframe which has a domain same than yours, then you will be able to use the $("iframe").contents().find("body") to manipulate the content.
If you have access to the iframed page you could use something like easyXDM to make function calls in the iframe and return the data.
If you don't have access to the iframed page you will have to use a server side solution.With PHP you could do something quick and dirty like:
<?php echo file_get_contents('http://url_of_the_iframe/content.php'); ?>