title: NSNotification argument in NSNotificationCenter method is nil
body: <p>I have this really unexplained problem with <code>NSNotification</code> method.</p>
  
  <p>I have been using <code>NSNotificationCenter</code> for  a long time but i can't explain why this is happening.</p>
  
  <p>My problem is this,</p>
  
  <p>I have a UITableViewCell subclass where i send a <code>NSNotificationCenter</code> method to the <code>UIViewController</code> when a user taps a button in the cell.</p>
  
  <pre><code>[[NSNotificationCenter defaultCenter] postNotificationName:MOVE_TO_PROGRAM_VIEW
                                                      object:self
                                                    userInfo:@{INDEX_ROW : [NSNumber numberWithInteger:self.tag]}];
  </code></pre>
  
  <p>Where the <code>self.tag</code> is the row (for the data model in the controller).</p>
  
  <p>In the controller i register for the notification in <code>viewWillAppear:</code> like so:</p>
  
  <pre><code>[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(userWantsToGoToProgramView:) name:MOVE_TO_PROGRAM_VIEW object:nil];
  </code></pre>
  
  <p>I also remove myself in the <code>viewWillDisappear:</code></p>
  
  <pre><code>[[NSNotificationCenter defaultCenter] removeObserver:self name:MOVE_TO_PROGRAM_VIEW object:nil];
  </code></pre>
  
  <p>Now in the method for the notification i try to get the userInfo and the row but the <code>notificaiton</code> argument is nil for some reason..</p>
  
  <pre><code>- (void)userWantsToGoToProgramView:(NSNotification *)notification
  {
      // notification is nil here
  
  
      // get the index of the video in the feed
      NSDictionary *userInfo = notification.userInfo;
      NSInteger videoIndex = [userInfo[INDEX_ROW] integerValue];
      NSDictionary *videoData = self.feed[videoIndex];
  
  }
  </code></pre>
  
  <p>Any advice of help will be appreciated</p>
  
  <p>Thanks! </p>