I am trying to figure out how OpenID works, therefore I am trying to write my own simple class for my web app that uses Google OpenID.
I am wondering if there are any examples that you know, or where I can find some details so I can implement my own class.
I am not looking for a very general class. I need something that will help me write my own implementation.
I have made good experiences with lightopenid (gitorious download). Unlike two other OpenID libraries I tried for PHP, it was very easy to use, has no external dependencies, is compatible with PHP5 and has no warnings.
There is an example for using Google.
And to display those buttons in the HTML page: http://code.google.com/p/openid-selector/