I have an existing login / registration system in PHP / MySQL and I would like to integrate Facebook login / registration to the website.
1. New users can click on the Facebook logo to approve registration with Facebook. If they agree to register, a user is created in my website's "users" MySQL table. When a user registers with their Facebook, they will be prompted to choose a username and we will automatically pull their email address from Facebook.
2. If a user is registered with Facebook, clicking on the Facebook logo will log the user in and create a PHP Session.
3. If a user has an account on the site, the user can then link their Facebook account with their site account allowing them to sign in with their Facebook from that point forward.
4. When a user is signed in with their Facebook account, their Facebook avatar is shown.
5. When a user is signed in with Facebook, they can navigate to a page that shows all of their Facebook friends. This page will show their friends that are registered on the website and allow them to invite their friends that are not registered on the site.
6. One last piece of functionality would be the ability for users that are logged in with Facebook to browse their Facebook photo library and upload a photo to the site (to a new table called photos) where the user could store a photo, and a description of the photo or upload a photo from their computer.
Attached are the existing user registration scripts and database, along with a placeholder page for the facebook photo upload page and invite friends from facebook page.