GCD and progressHUDs

Question

Using any form of progressHUD (SV, MB, etc) I run into this problem where the HUD is either hidden right after it is displayed or stays there permanently. In the below example, the HUD stays permanently, regardless of if the twitter feed (or page for other view controllers) has finished loading. How can I make the HUD disappear after the task in the separate thread completes?

[MBProgressHUD showHUDAddedTo:self.view animated:YES];
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{

       //Sets the auth key (user or app) for the RMACC Twitter Feed
       STTwitterAPI *twitter = [STTwitterAPI twitterAPIOSWithFirstAccount];

       [twitter verifyCredentialsWithSuccessBlock:^(NSString *username) {

           [twitter getUserTimelineWithScreenName:@"RMACCNewsNotes" count:10 successBlock:^(NSArray *statuses) {

               dispatch_async(dispatch_get_main_queue(), ^{
                   [MBProgressHUD hideHUDForView:self.view animated:YES];
               });

               self.twitterFeed =[NSMutableArray arrayWithArray:statuses];

               [self.tableView reloadData];

            } errorBlock:^(NSError *error){ }];

        } errorBlock:^(NSError *error) {
            [self twitterselfauthrequest];
        }];

    });        
}

score 1 · Answer 1 · answered Aug 17 '14 at 21:51

It is not secure capture self in a block: use: __weak typeof (self) weakSelf = self; out the first block.
You are calling [self.tableView reloadData]; not in the main thread;
This request: getUserTimelineWithScreenName could finish in an error: in that case you have not log so be sure that it finish with success.

score 1 · Accepted Answer · answered Aug 18 '14 at 15:58

1

It should be something like this:

[MBProgressHUD showHUDAddedTo:self.view animated:YES];
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{

// do all your twitter stuff, including the error checking

      dispatch_async(dispatch_get_main_queue(), ^{
         [self.tableView reloadData];
         [MBProgressHUD hideHUDForView:self.view animated:YES];
      });
});

answered Aug 18 '14 at 15:58

koen

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I was able to solve the issue with this method yesterday. Thanks for posting the solution. – jclark754 Aug 18 '14 at 16:52

score 0 · Answer 3 · answered Aug 17 '14 at 21:11

0

I've observed two things that could be a problem:

Are you sure that this line is launched in main thread?

[MBProgressHUD showHUDAddedTo:self.view animated:YES];
Are you sure that this line is launched at all?

[MBProgressHUD hideHUDForView:self.view animated:YES];

answered Aug 17 '14 at 21:11

Artem Stepanenko

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Ok. So could it be that all this code runs two times in a row? – Artem Stepanenko Aug 17 '14 at 21:53
Doesn't seem that way, generally I have an NSLog in there to say which twitterauth it used and when it completed and I've never seen it double up. – jclark754 Aug 17 '14 at 22:14

GCD and progressHUDs

3 Answers3