Handling different URL Schemes in iOS (Facebook and Instagram)

Question

I am not even sure how to define the problem but here it goes.

I have an application that uses Facebook SDK for user login. I followed the Facebook authorization tut

Answer 1

    - (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
    {
        NSLog(@"url: %@", [url scheme]);
        
        BOOL callBack;
        // Facebook Call back checking.
        if ([[url scheme] isEqualToString:@"facebook_url_schema"])
        {
            callBack = [FBAppCall handleOpenURL:url sourceApplication:sourceApplication];
        }
        // Instagram call back checking.
        else if ([[url scheme] isEqualToString:@"instagram_url_schema"])
        {
            callBack = [self.instagram handleOpenURL:url];
        }
        return callBack;
    }