Xcode: requestDidLoad FB Graph API doesn't get loaded

[kikovi]

I'm experiencing the next issue:

I have 3 classes that are taking data from Facebook API and are communicating through delegating. First class takes my friends, then for each friend 2nd class calls friend's events, return them and then for each friend's event, 3rd class calls event's ID to get full event infos. This is where the issue comes in, after calling 3rd class, the fb request api gets executed (requestLoading function gets started) but it doesn't wait in that class to get reply but just jumps out of the class.

Here is the code:

    // Class 1:
    // calling friends in first class
    - (void) callFriendData
    {
    PicShowAppDelegate* appDelegate = (PicShowAppDelegate*)[[UIApplication sharedApplication] delegate];
	Facebook *facebook = appDelegate.facebook;
    [facebook requestWithGraphPath:@"me/friends" andDelegate:self];
    }

    // receiving friends + calling friend class for each friend in which we will call events
    - (void)request:(FBRequest *)request didLoad:(id)result {
    NSMutableArray *data = [result objectForKey:@"data"];
    NSMutableArray *tmpFriendID = [data valueForKey:@"id"];
    NSMutableArray *tmpFriendName = [data valueForKey:@"name"];
    for(int i=0;i<[tmpFriendID count];i++)
    {
        FBFriend *fbFriend = [[FBFriend alloc]init];
        [fbFriend setDelegate:self];
        fbFriend.friendID = [tmpFriendID objectAtIndex:i];
        fbFriend.friendName = [tmpFriendName objectAtIndex:i];
        [fbFriend takeEvents];
        
        [friendDataArray addObject:fbFriend];
        [fbFriend release];
    }
    }

    // class 2, friend, here I call events

    - (void) takeEvents
    {
    PicShowAppDelegate* appDelegate = (PicShowAppDelegate*)[[UIApplication sharedApplication] delegate];
	Facebook *facebook = appDelegate.facebook;
    [facebook requestWithGraphPath:[NSString stringWithFormat:@"%@/events",self.friendID] andDelegate:self];
    }

    // receiving events for certain user
    - (void)request:(FBRequest *)request didLoad:(id)result {
    ....
    
    // sending events back to 1st class
    [[self delegate] eventsTaken:eventIDs fromFriendID:self.friendID];
    }

    // first class receives events for certain user, finds where he has to put them, and does so and then calls 3rd class, event
    - (void) eventsTaken: (NSArray *)idEvents  fromFriendID: (NSString*) idFrenda
    {
    
    for(int i=0;i<[friendDataArray count];i++)
        if([[[friendDataArray objectAtIndex:i] valueForKey:@"friendID"] isEqual:idFrenda])
            for(int j=0;j<[idEvents count];j++)
            {
                Event *event = [[Event alloc] init];
                event.eventID=[idEvents objectAtIndex:j];
                [event takeEvent];
                
                [event release];
            }
    }

    // 3rd class, event
    -(void) takeEvent
    {
    PicShowAppDelegate* appDelegate = (PicShowAppDelegate*)[[UIApplication sharedApplication] delegate];
	Facebook *facebook = appDelegate.facebook;
    [facebook requestWithGraphPath:[NSString stringWithFormat:@"%@",self.eventID] andDelegate:self];
    
    }

    // HERE IT FAILS, THIS NEVER GETS CALLED -> ??
    - (void)request:(FBRequest *)request didLoad:(id)result {
    ....
    }

[ianray]

Have you used NSLog statements to confirm the program flow?

Have you implemented the following?

- (void)request:(FBRequest *)request didReceiveResponse:(NSURLResponse *)response {
    NSLog(@"request:didReceiveResponse:");
}

- (void)request:(FBRequest *)request didFailWithError:(NSError *)error {
    NSLog(@"request:didFailWithError:%@:%d", error.domain, error.code);
}

The first step in debugging is always to get facts about program flow and error conditions. Hope this helps

[kikovi]

Hello, thanks for reply.

Yes I have implanted all those functions and they just don't get called, only requestLoading does. I ve set NSLogs everywhere and still can't identify the issue, this one is a hard one.

[idelovski]

This is wrong:

   NSMutableArray *data = [result objectForKey:@"data"];
   NSMutableArray *tmpFriendID = [data valueForKey:@"id"];
   NSMutableArray *tmpFriendName = [data valueForKey:@"name"];

In the first line you'll get array of dictionaries, so you need an -objectAtIndex: at some place. Something like this:

   NSArray       *data = [result objectForKey:@"data"];
   NSDictionary  *person = [data objectAtIndex:0];  // or in a loop
      
   NSString  *name = [person objectForKey:@"name"];
   NSString  *friendId = [person objectForKey:@"id"];

And you need to check everything you get from the server. Use isKindOfClass: on almost anything you get as response and check if it's nil.

Today I had a crash with the code that handles friends icons. My code would receive all the images except one, and then I had a crash. In debugger I found the reason, I got something useless as a result so -imageWithData: returned nil and in the next line I tried to put it into a dictionary so I had a crash. Well, now I check and if I don't get the proper image I just repeat request and this way all seem work out fine. At least, until I stumble upon something else.

[kikovi]

Originally Posted by idelovski

This is wrong:

   NSMutableArray *data = [result objectForKey:@"data"];
   NSMutableArray *tmpFriendID = [data valueForKey:@"id"];
   NSMutableArray *tmpFriendName = [data valueForKey:@"name"];

In the first line you'll get array of dictionaries, so you need an -objectAtIndex: at some place. Something like this:

   NSArray       *data = [result objectForKey:@"data"];
   NSDictionary  *person = [data objectAtIndex:0];  // or in a loop
      
   NSString  *name = [person objectForKey:@"name"];
   NSString  *friendId = [person objectForKey:@"id"];

And you need to check everything you get from the server. Use isKindOfClass: on almost anything you get as response and check if it's nil.

Today I had a crash with the code that handles friends icons. My code would receive all the images except one, and then I had a crash. In debugger I found the reason, I got something useless as a result so -imageWithData: returned nil and in the next line I tried to put it into a dictionary so I had a crash. Well, now I check and if I don't get the proper image I just repeat request and this way all seem work out fine. At least, until I stumble upon something else.

I don't think I need objectAtIndex since valueForKey:@"id" automatically checks all the objects and take their IDs into an array.

I ve added some isKindOfClass to reduce errors in future, but the problem remais. The issue is that the requestDidLoad doesn't even get loaded, I can't even po result in the debugger. The ID for event sent in request is correct - checked in Facebook graph api. Any more ideas what is going on?

[idelovski]

> I don't think I need objectAtIndex since valueForKey:@"id" automatically checks all the objects and take their IDs into an array.

Oh, oh. TIL that you can get values from array of dictionaries this way. This is so cool. I'm sure I'll need that trick one of these days.

> The issue is that the requestDidLoad doesn't even get loaded...

Put breakpoints in FBRequest.m in SDK, maybe in -connection:didReceiveResponse: and related delegate methods. Then inside -handleResponseData: and maybe -serializeURL: to see what url string do you have.

[kikovi]

Fixed, shouldn't release album so early.. Thanks for help everyone, though.