Question

From the facebook iOS API documentation, I’ve create two methods that request either the friends list from the graph, or details about the currently logged in user.

- (IBAction)showMyFriends:(id)sender {
    AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    [[delegate facebook] requestWithGraphPath:@"me/friends" andDelegate:self];
    NSLog(@"Getting friends list");
}
- (IBAction)showMyDetails:(id)sender {
    AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    [[delegate facebook] requestWithGraphPath:@"me" andDelegate:self];
    NSLog(@"Getting my info");
}

Sounds reasonable so far. The delegate method that responds from these calls is :

- (void)request:(FBRequest *)request didLoad:(id)result
{
    NSLog(@"Got a request");

// Print out friends
//    NSArray * items = [NSArray alloc];
//    items = [(NSDictionary *)result objectForKey:@"data"];
//    for (int i=0; i<[items count]; i++) {
//        NSDictionary *friend = [items objectAtIndex:i];
//        long long fbid = [[friend objectForKey:@"id"]longLongValue];
//        NSString *name = [friend objectForKey:@"name"];
//        NSLog(@"id: %lld - Name: %@", fbid, name);
//    }


// Print out self username
    NSString *username = [result objectForKey:@"name"];
    NSLog(@"Username is %@", username);
    helloGreeting.text = [NSString stringWithFormat:@"Hello %@", username];

}

Question : In the didLoad, how can you check which graph request the current invocation relates to? For example, in the above code I would either want to print out the friends list, or print out the username, so I would image I need to wrap the code in some case/switch statement dependant on the request type.

I couldn’t find anything obvious on the API, what is the best approach for ensuring only relevant response code is executed?

Answer 1

Actually looks like Hackbook is doing a switch based on an int called “currentAPICall”, setting an int for each request, then checking on that in the return. So it’s all done in the main thread, I’m guessing.

I also have different result objects, of different types. I end up looking at the result and determining if it’s from the /me request or from the /home. I have various “ifs” looking at the returning object. Not ideal by any means. I.e.

if([result objectForKey:@"first_name"]){
    // back from getMe()
}

if ([result objectForKey:@"data"]) {
    // more checking here- I have two calls that return a data object
}

Update: this doesn’t work for asynchronous requests, and most of these are, so I used the method above, checking request.url, instead, and that works like a charm.