Porthole is a small library for secure cross-domain iFrame communication.

Usage

Include the Javascript.

<script type="text/javascript" src="porthole.min.js"></script>

Create your content iFrame. This is where the guest content lives. Make sure to give it a name.

<iframe id="guestFrame" name="guestFrame" src="http://other-domain.com/">
</iframe>

Define an event handler if you want to receive messages.

function onMessage(messageEvent) {  
    /*
   messageEvent.origin: Protocol and domain origin of the message
   messageEvent.data: Message itself
   messageEvent.source: Window proxy object, useful to post a response 
   */
}

Create a window proxy object on the main page.

var windowProxy;
window.onload=function(){ 
    // Create a proxy window to send to and receive 
    // messages from the iFrame
    windowProxy = new Porthole.WindowProxy(
        'http://other-domain.com/proxy.html', 'guestFrame');

    // Register an event handler to receive messages;
    windowProxy.addEventListener(onMessage);
};

Create a window proxy object in the iFrame.

var windowProxy;
window.onload=function(){ 
    // Create a proxy window to send to and receive 
    // messages from the parent
    windowProxy = new Porthole.WindowProxy(
        'http://parent-domain.com/proxy.html');

    // Register an event handler to receive messages;
    windowProxy.addEventListener(function(event) { 
        // handle event
    });
};

Send a message.

windowProxy.post({'action': 'supersizeme'});

Note that if you have multiple iFrames, you can create as many WindowProxy objects as needed.

Update

The library has been updated. It is not compatible with previous versions.

• Support JSON serialization
• Bug fix for IE 8
• Bug fix for multiple event handler in native browser support.

Unit Tests

rake jasmine

Demo

http://sandbox.ternarylabs.com/porthole/

Project Page

http://ternarylabs.github.com/porthole/