I have been comissioned to make a website complete with a user login system with multiple user groups. The users of this site will most likely also be administrators of facebook groups as well. Does anyone know if it is possible to associate facebook credentials with the login, and be able to send out group wide messages from this separate site?
I have planned on using php/mysql for the the bulk of the site function.
thanks.
You can use Facebook Connect functionality as a login mechanism for the users of your website.
Here is a Tutorial.
http://wiki.developers.facebook.com/index.php/Connect/Authentication_and_Authorization
You might consider using Facebook Connect for the login as well, as this would allow for easier access to the Facebook API.
If this is not an option, then I'd suggest that logged in users use Facebook connect to authorize your site to do any necessary operations. This would require you to get offline access -permissions from the users as then you could use the Facebook API to without the session key.
Facebook Connect docs: http://wiki.developers.facebook.com/index.php/Facebook_Connect
Offline access: http://wiki.developers.facebook.com/index.php/Offline_access
Connecting your site user accounts with Facebook accounts is possible with Facebook Connect. However there are no API calls you can make to send messages out to groups, presumably because Facebook is (wisely) worried about the spam risk. It's possible to construct a pre-filled message using a link to the "compose message" form and pass in content and a user ID, but this only works for a single ID at a time so again is not going to be useful. (If you tried sending multiple messages in sequence you're likely to have accounts shut down for spamming by Facebook's auto-detection algorithms.)
Facebook's recent changes mean you can request e-mail addresses for users, but that requires them to add an application so again is unlikely to be any of any help in your group situation.