What's a good design pattern to find my app's users' friends (facebook, linkedIn, twitter), etc who are also configured with my app?
Eg, my party app has party organizers. The organizers add party people by name/email. Later a party person logs in via Facebook. I want to show her which of her friends will also be at the party.
Should I
send an email to ALL party people, asking them to login to my app via FB, Twitter, LinkedIn? I'd send the email as soon as I get the email address. That way, later, when someone logs in, I can exactly match by FB/LinkedIn id and tell the user which of their friends/connections is also attending the party
When a person logs in via LinkedIn, FB, show just the friends/connections of others who have previously logged in. (Can't verify FB/LinkedIn friends by email, just by id. So need to wait until my app has learned the FB/linkedIn id of the other person when they logged in.)
When a person logs in via LinkedIn, FB, show the friends/connections that MAY be attending the party? -- By doing a match on fname/lname? This method doesn't require that the friend has already logged into my app, but does mean that I could say that "Your friend Jim Jones may be the same as the Jim Jones who is attending the party"
Any good examples of this design pattern?
Thanks,
Larry