iOS: UITableView mixes up data when scrolling too fast - ios

Question

I've subclassed the UITableViewCell to add custom appearance to it. At the init level of the MYTableViewCell I added 4 subviews: UIImageView, and three UILabel(s). All 4 subviews have a different Tag assigned to them.
Inside the cellForRowAtIndexPath method I either create a new cell if it wasn't available at first, or reuse available one and assign the proper text to the ui labels.
The problem I am having is that if I try to scroll super fast, then the data gets messed up, however if I scroll up and down more slowly, then everything works fine.
Any thoughts??
Below is the code:
- (MyTableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"itemListTableViewCell";
MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
DisplayableEntity *displayableEntity = [self.fetchedResultsController objectAtIndexPath:indexPath];
if( ! cell ) {
cell = [[MyTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
[self tableView:tableView appearanceForCell:cell withEntity:displayableEntity];
} else {
UIImageView *imageView = (UIImageView *) [cell viewWithTag:IMAGEVIEW_TAG];
imageView.image = [UIImage imageNamed:displayableEntity.displayImageName];
UILabel *titleLabel = (UILabel *) [cell viewWithTag:TITLEVIEW_TAG];
titleLabel.text = displayableEntity.entityName;
UILabel *itemDescription = (UILabel *) [cell viewWithTag:DESCRIPTION_TAG];
itemDescription.text = displayableEntity.entityDesctiption;
}
}
// some code removed to make it brief
- (void)tableView:(UITableView *)tableView appearanceForCell:(MyTableViewCell *)cell withEntity:(DisplayableEntity *)entity {
// cell image view
UIImageView *cellImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[entity displayImageName]]];
[cellImageView setTag:IMAGEVIEW_TAG];
[cell addSubview:cellImageView];
// adding entity name label
UILabel *itemTitleName = [self itemTitleNameLabelWithFrame:itemNameLabelRect itemName:[entity entityName]];
[itemTitleName setTag:TITLEVIEW_TAG];
[cell addSubview:itemTitleName];
// adding 'assigned to' label right under the item name label
UILabel *itemDescriptionLabel = [self itemDescriptionLabelWithFrame:descriptionLabelFrame itemDescription:[entity entityDesctiption]];
[itemDescriptionLabel setTag:DESCRIPTION_TAG];
[cell addSubview:itemDescriptionLabel];
}

Answer 1

I see some troubles in tableView:cellForRowAtIndexPath: logic
It should be:
Dequeue cell
If cell cannot be dequeued - create the new one
Set all cell properties
I mean something like this:
- (MyTableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"itemListTableViewCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
} // <-- Note there is no else, we should reset properties in both cases
NSManagedObject *managedObject = [_fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [managedObject valueForKey:#"text"];
cell.imageView.image = [managedObject valueForKey:#"image"];
return cell;
}