Databases
StackOverflow2013
Postsdbo
PONSNotification not sent/received
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PONSNotification not sent/received
    primarykey
    data
    text
    <p>I've been trying to figure this out for a whole day now and I'm starting to become desperate... So here is my problem:</p> <p>I have a table view controller showing a list of files. The user can download new files to this list. I handle the downloads asynchronously in a separate class. When a new file has been downloaded I want to notify the table view controller, so it can update the list. The delegate pattern doesn't really fit here, because multiple instances have to be notified, so I want to use NSNotificationCenter.</p> <p>In the view controller's viewDidAppear: method I register as an observer:</p> <pre><code>[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(downloadComplete:) name:kDownloadCompleteNotification object:nil]; </code></pre> <p>This is called definitely before posting the notification, because the user has to tap the add button on the view controller to start a new download. When the download is done I post the notification (in the DownloadManager class):</p> <pre><code>[[NSNotificationCenter defaultCenter] postNotificationName:kDownloadCompleteNotification object:self]; </code></pre> <p>However, my notification handler method in the view controller is never called. I added breakpoints and it's just not called. I also tried to set the object to nil. No difference.</p> <pre><code>- (void)downloadComplete:(NSNotification *)notification { NSLog(@"Inserting new files into table view."); } </code></pre> <p>Both, registering and posting the notification is done on the main thread (I don't think that matters anyway). The view controller is not released or anything. I didn't make any typo as far as I can tell. The name strings are the same constant. </p> <p>If set the name argument to nil when registering as an observer, I receive all kind of (system) notifications, but not my own ones. However if I post a test notification right after registering (in viewDidAppear) it works.</p> <p>I don't know what else I should check... Any hint is very appreciated. Thanks!</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USRob Keniger
    1. USDrummerB
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PONSNotification not sent/received
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIt very much sounds like one of your objects *is* being deallocated.
      singulars
      1. PONSNotification not sent/received
      1. USRob Keniger
    2. COYou've logged the registration and post to prove they happen in the correct order? Also log any time you remove an observer.
      singulars
      1. PONSNotification not sent/received
      1. USFiroze Lafeer
    3. COWhat a big oversight of me... I remove the observer in viewDidDisappear, because I only need to update the list in the visible view controller. However at the time when the notification is sent, the download view controller is actually on top of my file list view controller.
      singulars
      1. PONSNotification not sent/received
      1. USDrummerB
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload