I am integrating facebook iOS SDK 4.0 in my mobile app. I came into scenario where user logged into our mobile app with facebook credentials, after some time the user changed his password and Firstname in facebook. Now How do I track this change in mobile app? and redirect user to validate facebook credentials in mobile app?Answer1:
In both v3 and v4 of the SDK, the access token is cached locally on the device (by default), and the only way to know if it's still "valid" is to make a graph request.
You can make a /me or /permissions request during app start if you have a cached token, and check for errors, and prompt the user to re-log in if the token is no longer valid. There are also some auto-error recovery mechanisms built into the SDK, see <a href="https://developers.facebook.com/docs/ios/errors" rel="nofollow">https://developers.facebook.com/docs/ios/errors</a>.