Delegate with UITableViewCell - ios

Question

I'm trying to hide a label in my TableViewCell when I go into "editing mode". So I created a protocol:
// UITableView Class
#protocol CellDelegate <NSObject>
- (void)toggleOpacityOff
- (void)toggleOpacityOn
#end
//in #interface
#property (nonatomic, strong) id <CellDelegate> delegate;
I implemented these methods in the UITableViewCell class and passed the delegate to the cell class:
// cellForRowAtIndexPath method
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
self.delegate = cell;
return cell;
But when I run this the methods apply only to the top most cell in the TableView.
Why is that and how can I fix it? Many thanks! :)

Answer 1

You should be able to fix this by changing the following line to set the correct delegate (remember that delegates should always be weak, not strong!):
self.delegate = cell;
to line:
cell.delegate = self;
The longer explanation is that delegate would not be the correct way to achieve this.
Delegates are meant to message back some specific action or information, this way your cell would actually tell the delegate that it had something togged on or off. This makes no sense, because you are looking to toggle something off.
The correct way of achieving your goal is to create a UITableViewCell subclass and implement those methods on a cell (toggleOpacityOff and toggleOpacityOn). Or even better create a specific cell property and override it's setter. Then you call this method in UITableViewDelegate method tableView:didSelectRowAtIndexPath:. See the following example:
#interface MyCell : UITableViewCell
#property (nonatomic) BOOL opacity;
#end
#implementation MyCell
- (void)setOpacity:(BOOL)opacity
{
if (opacity)
{
// Set opacity to ON
...
}
else
{
// Set opacity to OFF
}
}
#end
To loop through all cells:
- (void)updateCells
{
for (NSInteger i = 0; i < [self tableView:self.tableView numberOfRowsInSection:0]; i++)
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:i inSection:0];
MyCell *cell = (MyCell *)[self tableView:self.tableView cellForRowAtIndexPath:indexPath];
cell.opacity = YES;
}
}
In addition to this, it might be wise to remember this state in your model, so it remains correct when cells are reused (when scrolling).

Answer 2

Just keep some BOOL in your tableview class like isInEditMode. Then you add something like this into your cellForRowAtIndexPath
if (isInEditMode)
[cell.myText setHidden:YES];
else
[cell.myText setHidden:NO];
And once you want to switch into edit mode you just do this
self.isInEditMode = YES;
[self.tableview reloadData]