Cross domain iframe issue

Question

For say i have a Site called example.com on which iframe is embedded of domain iframe.net, now i want to read the content of iframe and pass some parameter to display a textual message. Like Hi with username.

Now the problem is this able not able to make connection between the two , even am not able to get the innerHTML of iframe i used following approach

document.getElementById('myframe').contentWindow.document.body.innerHTML; 

It throws error "Permission denied to access property"

Do anyone know how to read and write in cross domain platform

Answer 1

If you don't have control over the framed site, you cannot circumvent the cross-domain policy.

If you have control over both sites, you can use the postMessage method to transfer data across different domains. A very basic example:

// framed.htm: window.onmessage = function(event) {     event.source.postMessage(document.body.innerHTML, event.origin); };  // Main page: window.onmessage = function(event) {     alert(event.data); };  // Trigger: // <iframe id="myframe" src="framed.htm"></iframe> document.getElementById('myframe').contentWindow.postMessage('','*'); 

Answer 2

In Internet Explorer 8, events passed as a parameter may be null, that is why you need to access the event in a different manner:

In frame.html:

window.onmessage = function(event) {    var evt = event || window.event;    evt.source.postMessage('Message from iFrame', evt.origin); }; 

On main.html:

window.onmessage = function(event) {    var evt = event || window.event;    alert(evt.data); }; 

The event is triggered the same way as Rob W has presented:

document.getElementById('frameId').contentWindow.postMessage('message','*');