Facebook authentication needed in my web applicication in order to use Graph API?

Question

I want my web application, which is built with Ruby on Rails, to communicate with the Facebook Social Graph API, but I am aware of that I need some kind of authorization to achieve that.

So, do I need to build OAuth authentication for my application to make use of auto-publishing messages on the user's Facebook wall? If not, how could I integrate the social features into my web application?

The web application already has an existing user base; could I also allow my application to get Facebook access? If yes, how?

I would appreciate examples of sites who do this kind of integration really well, also with other services like Twitter, LinkedIn, etc..

Answer 1

All is explained on the facebook developers site:

http://developers.facebook.com/

This explains the auth you need to access graph http://developers.facebook.com/docs/guides/web/#login

You can then combine graph info with your existing user database by saving their facebook ID number hence then you can pull up profile pics etc

Answer 2

Try using the following gems:

1. Devise : User authentication (If you already have the framework for user authentication, this will not be needed.
2. Omniauth : Facebook (or any other OAauth eg Twitter) authentication
3. Koala : Facebook open graph api

If you need only Facebook integration, Koala should be sufficient. For making them work together check this: Making OmniAuth, Devise and Koala work together