I gave recently a talk on Web Messaging API. I'm not a specialist of this API but Tiffany Brown (@webinista) has written a comprehensive article about Web Messaging API on dev.opera.com.
You might know it better under the name of
window.postmessage("message", targetOrigin)
What I learned and shared with others during this talk.
- The only safe place for interoperability is a parent document and an iframe (on two different domains). This will even work on Opera Mini
- Using the magical "/" string for targetOrigin will help when you control the two documents on a same domain but will break when one day you will move things around. So avoid.
- DO NOT EVER use the magical string "*" for targetOrigin or fear the demons of security and cross-site-scripting.
- Opera has the best implementation across the board
- ChannelMessage (using a window has a hub for two iframes for examples) is yummy but is not entirely available in all browsers.
If you have other issues, recommendations, chime in the comments.\