How do I reload a Collection View automatically?

Question

I have developed an RSS reader application using collection views. My problem is, on the very first launch, the app comes up blank.

The process is, the RSS feed is pulled from the web, stored to a temporary file on the device and then displayed via collection views.

My question is How Do i get the app to reload the data automatically once the files have been loaded? So that the user does not see an initial blank screen.

I have tried adding this code

       [self.collection1 performBatchUpdates:^{
       [self.collection1 reloadSections:[NSIndexSet indexSetWithIndex:0]];
   } completion:nil];

However it does not work for the initial view.

Should I do something from the appdelegate? or from the collection view controller itself?

Please advise

Below is the code used to get and display my data....

#pragma mark - UICollectionViewDataSourceDelegate
- (NSInteger) numberOfSectionsInCollectionView:(UICollectionView *)collectionView
  {
  return 1;
  }

- (NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
 return [_articleListmain count];
}

- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
 MainCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"articleCellmain"
                                                                           forIndexPath:indexPath];
NSDictionary *item = [_articleListmain objectAtIndex:indexPath.item];

// set the article image
[cell.image setImageWithURL:[item objectForKey:@"image"]];

// set the text of title UILabel
cell.title.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"title"]];
cell.title.textColor = [UIColor colorWithRed:33.0f/255.0f green:74.0f/255.0f blue:146.0f/255.0f alpha:1.0f];

// set the text of summary UILabel
cell.description.text = [NSString stringWithFormat:@"%@\n\n\n\n\n\n\n\n\n", [item objectForKey:@"description"]];


cell.targetURL.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"link"]];

cell.category.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"category"]];

cell.date.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"pubDate"]];

cell.image.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"placement.png"]];


return cell;


}

Answer 1

You should be able to use [collectionView reloadData] once you know the download has completed.

Answer 2

try this

 [self.collection1 performBatchUpdates:^{
   [collectionView reloadData]
 } completion:nil];

once your download has completed.