Reuse UITableViewCell's without data repetition - ios

Question

I'm having some problem with multiple custom UITableViewCell reuse. I have 3 types of custom UITableViewCell. I tried to reuse the UITableViewCell using dequeueReusableCellWithIdentifier.
I wrote the prepareForReuse and made all possible subviews data nil. But still I was getting some repetitions of data in some UITableViewCell's. So I was thinking of reusing just the xib without any data.
I made up the following code. The app seems to have some freezing problem now. Somebody please show me the correct way to reuse tableview UITableViewCells without data repetition.
static NSString *cellIdentifier = #"SystemListCell";
IXSystemMessageCustomCell *cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[[NSBundle mainBundle] loadNibNamed:#"IXSystemMessageCustomCell" owner:self options:nil] objectAtIndex:0];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
IXSystemMessageCustomCell *cellToSave = cell;
[self configureSystemCell: cellToSave atIndexPath:indexPath];
return cellToSave;

Answer 1

Do not modify the data in prepareForReuse
A better way is to
dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath
We should always modify the data in cellForRowAtIndexPath as this helps in reuse of cells.
Also, since you have created IXSystemMessageCustomCell class it is better to use this :
[[IXSystemMessageCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]
and write the setup code in initWithStyle:reuseIdentifier:
instead of this:
cell = [[[NSBundle mainBundle] loadNibNamed:#"IXSystemMessageCustomCell" owner:self options:nil] objectAtIndex:0];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
Cheers!

Answer 2

You can use 3 different reuse identifier for your 3 cell types:
IXSystemMessageCustomCell *cell;
if (some condintion) {
cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:"CellReuseIdentifierType1"];
} else if (some condition 2) {
cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:"CellReuseIdentifierType2"];
} else {
cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:"CellReuseIdentifierType3"];
}
In this case you don't need to re-configure cell each time for each cell type

Answer 3

Try this...
IXSystemMessageCustomCell *cell = nil;
cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
By setting your cell to nil first, you are clearing out previous data associated with the reused cell.
Also register your nib once in your viewDidLoad or similar table view lifecycle method, so that this is not required at every call to tableView:cellForRowAtIndexPath.
So extract your static call from any method to be a private declaration...
static NSString *cellIdentifier = #"SystemListCell";
and adjust your methods to read...
- (void)viewDidLoad {
UINib *nib = [UINib nibWithNibName:#"IXSystemMessageCustomCell" bundle:nil];
[<<self.tableView>> registerNib:nib
forCellReuseIdentifier:cellIdentifier];
<< ... other code ... >>
}
and
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
IXSystemMessageCustomCell *cell = nil;
cell = (IXSystemMessageCustomCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
[self configureSystemCell:cell atIndexPath:indexPath];
return cell;
}