FBSDKGraphRequest in a bolts framework never calls block

Question

I have the following code:

[[[PFFacebookUtils logInInBackgroundWithAccessToken:[FBSDKAccessToken currentAccessToken]] continueWithSuccessBlock:^id(BFTask *task) {

    PFUser *user = task.result;

    return user;

}] continueWithSuccessBlock:^id(BFTask *task) {

    BFTaskCompletionSource *source = [BFTaskCompletionSource taskCompletionSource];

    FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:nil];

    [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {

        if (error) {
            [source setError:error];
            return;
        }

        [source setResult:result];
    }];

    return source.task;
}];

The FBSDKGraphRequest works fine outside of the Bolts task, but inside the task the startWithCompletionHandler is not being called.

Any ideas?

Crosby

Answer 1

I found a workaround. Just wrap it within a main thread block. It will work like a charm.

dispatch_async(dispatch_get_main_queue(), ^{
    FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:nil];

    [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {

        if (error) {
            [source setError:error];
            return;
        }

        [source setResult:result];
    }];
});

Shoran

This is a huge fix. Should have more upvotes. Thank you @yuhua! – Timms

still not never calls the block of handler :( – Pettaway

worked for me. I was calling this "initWithGraphPath" from background thread and apparently it should be only invoked from the main thread. – Unlikelihood

Answer 2

We had the same exact issue and we used the same solution but I can not seem to find any posts which explain why this is happening.

Lodhia

Now it's all open source we ought to be able to work out why. I'll revisit if I get the time and get back to you. – Crosby

Thank you! Let me know if there is anything I can help with or look at myself. I might have some free time this week to help out. – Lodhia

Answer 3

I ran into the same issue. It appears that PFFacebookUtils is executing its continuation block on a different thread but it appears that FBSDKGraphRequest expects to be started from the main thread. I found the issue can alternatively be solved by specifying an executor.

BFTask* loginTask = [PFFacebookUtils logInInBackgroundWithReadPermissions:@[]];
[loginTask continueWithExecutor:[BFExecutor mainThreadExecutor] withSuccessBlock:^id _Nullable(BFTask * _Nonnull task) {
    FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:nil];
    [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
        // This code gets called properly
    }];
}];

Angel