Facebook API - How to cancel Graph Request

Question

I occasionally need to cancel a FaceBook graph request, but there seems to be no cancel or similar method in their API to do so. At the moment, crashes sometimes occur as th

Answer 1

Since SDK 3.1, it's very easy, as startWithCompletionHandler: returns a FBRequestConnection object, which has a -(void)cancel; method.

For example:

// In interface or .h definitions:
@property (strong, nonatomic) FBRequest             *fBRequest;
@property (strong, nonatomic) FBRequestConnection   *fbConnection;

// when needed in class (params should be set elsewhere, this is just an example):
self.fBRequest = [[FBRequest alloc] initWithSession:[FBSession activeSession] graphPath:@"me/photos" parameters:params HTTPMethod:@"POST"];
self.fbConnection = [self.fBRequest startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error){
    NSLog(@"Publish complete, error: %d", error.code);
}];

// now, to cancel anywhere in the class, just call:
[self.fbConnection cancel];

Answer 2

I've followed Matt Wilding's approach listed here, which was very useful, thanks Matt. Unfortunately it didnt quite work for me, so I made some tweaks and now it works... also this revised approach keeps out of the core facebook classes...

//in .h define an FBRequest property
@property (nonatomic, retain) FBRequest * pendingFBRequest;

//in .m when making your request, store it in your FBRequest property
pendingFBRequest = [facebook requestWithGraphPath:@"me/feed"
                                        andParams:params
                                    andHttpMethod:@"POST"
                                      andDelegate:self];

//create a timer for your timeout
pendingFacebookActionTimer = [NSTimer scheduledTimerWithTimeInterval:15.0 target:self selector:@selector(onPendingFacebookActionTimeout) userInfo:nil repeats:NO];

//cancel the action on the timeout's selector method
-(void)onPendingFacebookActionTimeout {

    [pendingFBRequest.connection cancel];

}

Answer 3

Try this instead of using NSTimer:

FBRequest *fbRequest = [facebook requestWithGraphPath:@"me" andDelegate:self];
[self performSelector:@selector(fbRequestTimeout:) withObject:fbRequest afterDelay:30];

- (void)fbRequestTimeout:(FBRequest *)fbRequest
{
    [fbRequest.connection cancel];
    [fbRequest setDelegate:nil];
}