Web hook up
Implement Web Hooks in this way in your application if you want to allow others to truly extend and enhance the abilities of your application.By letting the user specify a URL for various events, the application will POST data to those URLs when the events occur.The general idea is that a web application sending out data via Web Hooks will also use the response to modify its own data.At Facebook, when you access an app, Facebook sends a Web Hook out to your application saying "Hey, someone's accessing your application, what do I do?!" The application responds with, "Show the user this page..." Facebook does so, and the pattern continues in the same manner as you continue to use the application.At Google Wave, when you do something in a wave, any robot you've added as a participant is notified via a Web Hook, and the robot has the ability to modify the wave in its http response.A Pipe happens when your Web Hook not only receives real-time data, but goes on to do something new and meaningful with it, triggering actions unrelated to the original event.
How you use it is up to you and whatever you want to accomplish.
A Web Hook is an HTTP callback: an HTTP POST that occurs when something happens; a simple event-notification via HTTP POST.
A web application implementing Web Hooks will POST a message to a URL when certain things happen.
You can use this form of Web Hooks to allow others to extend your application.
Facebook's Application Platform uses Web Hooks in this way, and so does Google Wave's robot integration.