Login to Facebook using FBGraph

Question

I am new in iOS development. I want to connect to Facebook from my iPhone app. I followed FBGraph API to see how we can use Facebook in our App like:

Prints the inf

Answer 1

On click of button and its event is say fbLogin then add this code for login

-(void)fbLogin
{
   if(!self.fbGraph.accesstoken) // doesnot have access token. So needed to login
   {
    NSString *client_id = @"130902823636657"; //get your own client id from facebook

    //alloc and initalize our FbGraph instance
    self.fbGraph = [[FbGraph alloc] initWithFbClientID:client_id];

    //begin the authentication process.....
    [self.fbGraph authenticateUserWithCallbackObject:self andSelector:@selector(fbGraphCallback:) andExtendedPermissions:@"user_photos,user_videos,publish_stream,offline_access,user_checkins,friends_checkins"];
   }
   else
   {
      // Add UIAlert as user is logged in already
      //pop a message letting them know most of the info will be dumped in the log
      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Note" message:@"user is logged in already" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
      [alert show];
      [alert release];
   }
}

Now when user is authebticated this method below is called. So add this method in your .h file.

#pragma mark -
#pragma mark FbGraph Callback Function
/**
* This function is called by FbGraph after it's finished the authentication process
**/
- (void)fbGraphCallback:(id)sender 
{

 if ( (self.fbGraph.accessToken == nil) || ([self.fbGraph.accessToken length] == 0) ) 
 {

  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Note" message:@"Try Again" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
  [alert show];
  [alert release];

  //restart the authentication process.....
  //[self.fbGraph authenticateUserWithCallbackObject:self andSelector:@selector(fbGraphCallback:) andExtendedPermissions:@"user_photos,user_videos,publish_stream,offline_access,user_checkins,friends_checkins"];

 } 
 else 
 {
  //pop a message letting them know most of the info will be dumped in the log
  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Note" message:@"Logged In Successfully" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
  [alert show];
  [alert release];
  NSLog(@"------------>CONGRATULATIONS<------------, You're logged into Facebook... Your oAuth token is: %@", self.fbGraph.accessToken);
 }
}