Using dequeueReusableCellWithIdentifier with custom UITableViewCell - iphone

Question

So I'm unsure how this dequeueReusableCellWithIdentifier works and if what I'm looking for is possible. I have a custom UITableViewCell with a BOOL showIcon. In the TableViewCell, if it's true, I show it, otherwise, I don't show this icon on my cell. In my cellForRowAtIndexPath, I grab the object in my array from my model, and set it for the UITableViewCell property.
This works at first on what is visible on my screen. Then as I scroll downwards on the table, it does not work and the values I should be seeing for the showIcon just don't show. And then when I scroll back to the top, the original icons that were there, are not there. Is the dequeueReusableCellWithIdentifier still what I want to be using in this case? Or am I doing something wrong with setting and showing data in it? Thanks a bunch.
CODE:
On my custom UITableViewCell, I have a
BOOL showIcon;
In my cellForRowAtIndexPath method, I use the UINib way of getting my custom UITableViewCell like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSUInteger row = [indexPath row];
static NSString *OrderTableViewCellIdentifier = #"OrderTableViewCellIdentifier";
OrderTableViewCell *cell = (OrderTableViewCell *)[tableView dequeueReusableCellWithIdentifier:OrderTableViewCellIdentifier];
if (cell == nil) {
UINib *cellNib = [UINib nibWithNibName:#"OrderTableViewCell" bundle:nil];
[cellNib instantiateWithOwner:self options:nil];
cell = self.TbvCell;
[cell.CheckmarkButton addTarget:self action:#selector(CheckmarkButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
self.TbvCell = nil;
}
Order *order = [orderArray objectAtIndexPath:row];
cell.order = order;
}
Then in my TableViewCell, it's something like this:
#property (nonatomic, retain) Order *order;
#property (nonatomic, retain) UIImageView *icon;
overridden setter:
- (void)setOrder:(Order *)newOrder {
if (!order.showIcon) {
icon.hidden = YES;
}
}

Answer 1

Your code reuse your cell so you have to cover all the case in your setOrder method. Try with:
- (void)setOrder:(Order *)newOrder {
if (!order.showIcon) {
icon.hidden = YES;
}
else {
icon.hidden = NO;
}
}
Or simpler:
- (void)setOrder:(Order *)newOrder {
icon.hidden = !order.showIcon;
}

Answer 2

Yes, dequeueReusableCellWithIdentifier works well with any custom UITableViewCell subclasses. However, keep in mind that this method is for memory saving, so you'll have to do the following (even with not subclassed, normal UITableViewCells):
This method returns an already used UITableViewCell instance (or nil if the table view doesn't have enough cells yet). It means that the cell won't be "empty"; you'll need to clear and re-set all its properties. For example, you'll need to be able do decide from the cell's corresponding NSIndexPath whether its icon has to be displayad, and what icon image you'd like to use at all.
So edit your code like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSUInteger row = [indexPath row];
static NSString *OrderTableViewCellIdentifier = #"OrderTableViewCellIdentifier";
OrderTableViewCell *cell = (OrderTableViewCell *)[tableView dequeueReusableCellWithIdentifier:OrderTableViewCellIdentifier];
if (cell == nil) {
UINib *cellNib = [UINib nibWithNibName:#"OrderTableViewCell" bundle:nil];
[cellNib instantiateWithOwner:self options:nil];
cell = self.TbvCell;
[cell.CheckmarkButton addTarget:self action:#selector(CheckmarkButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
self.TbvCell = nil;
}
// set your cell's properties to default values.
// e. g.: cell.showIcon = NO; and so on
Order *order = [orderArray objectAtIndexPath:row];
cell.order = order;
// then do a recustomization using the NSIndexPath's -row and -section properties
}
Hope this will help.