I am building a social platform in Codeigniter..And i wish to implement a Social Login Option like StackOverflow(which uses OpenId) where user can select Facebook, LinkedIn, Twitter or Google to login into my site.. I know of few PHP libraries like OpenId, A3M for CI..
My query is will A3M detect a user loggin in via Linked In is already a signed-up user who initially used FB and map both the Ids with the same user instead of generating new User.
Is there a better suggested alternative to A3M for my requiremnets
You can have a look at Phil Sturgeon's 'Codeigniter OAuth'.
An implementation of the OAuth protocol with drivers to work with different providers such as Twitter, Google, etc.
OAuth: https://github.com/philsturgeon/codeigniter-oauth
and
OAuth 2.0: https://github.com/philsturgeon/codeigniter-oauth2
Both, and others are also available at http://getsparks.org/packages/summary