Facebook login integration and facebook registration integration | Facebook api programmers

We can customize existing angularjs scripts.

Facebook login and registration integration.
Users can signup and register in the custom website.
After registration the user can link his existing facebook account with the newly registered website account.
Once the account is linked, next time if the user visits the website AFTER logging in to facebook first then the user will be automatically logged into the website.
Facebook opengraph API is used with the php facebook sdk. Our facebook api developers can integrate existing scripts with facebook.