Values entered in custom UITableViewCell UITextField translated to other fields - ios

Question

So, this is going to be a very strange problem to address. I will try to be as specific as possible.
Here is a snippet from my UITableViewController:
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"miscCell";
JASMiscConfigurationTableViewCell *cell = ((JASMiscConfigurationTableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier]);
if (cell == nil) {
cell = [[JASMiscConfigurationTableViewCell alloc] init];
}
JASMiscellaneous *misc = [((NSMutableArray *)[_miscellaneousList objectAtIndex:indexPath.section]) objectAtIndex:indexPath.row];
[cell.itemNameLabel setText:misc.itemDescription.productCostDescription];
if ([misc.itemQuantity doubleValue] > 0) {
[cell.itemQuantityField setText:[misc.itemQuantity stringValue]];
}
return cell;
}
JASMiscConfigurationTableViewCell is just a custom UITableViewCell with a label and textfield.
The issue at hand here is:
If I enter a value into a UITextField in the cell and I scroll down the page, the value entered literally translates down the page as I scroll. It always manages to rest directly inside the UITextField of another row cell when I stop scrolling. The value entered does not disappear when it leaves its original UITextField, it floats at the forefront of the screen. This is not solely a GUI bug, either. When I iterate through the cells for their values to store them in objects, the UITextField the value has translated to is actually holding the value. What's stranger still is that the original UITextField the value was entered in is also still holding the value. When I leave the screen and reenter, both text fields with hold the value.
I'm sorry if this sounds confusing. It's confusing to me. If you need any clarification I would be happy to provide it. Help is appreciated.

Answer 1

Normal allocation cell = [[JASMiscConfigurationTableViewCell alloc] init]; is different from allocating with -reuseIdentifier like..
cell = [[JASMiscConfigurationTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
it is possible that
JASMiscConfigurationTableViewCell *cell = ((JASMiscConfigurationTableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier]);
keeps on using the previous cell.
try this:
static NSString *cellIdentifier = #"miscCell";
JASMiscConfigurationTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier]);
if (cell == nil) {
cell = [[JASMiscConfigurationTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
About the held/replaced when the cell leaves and reenters view
you are missing the else statement:
if ([misc.itemQuantity doubleValue] > 0) {
[cell.itemQuantityField setText:[misc.itemQuantity stringValue]];
}
//set value if the condition is not met.
cell.itemQuantityField.text = #"no";

Answer 2

Table views re-use cells. When a cell is scrolled offscreen it is added to a queue, and will be re-used for the next cell to be scrolled onscreen. That means your configuration code in tableView:cellForRowAtIndexPath: method will be run again on the same cell at different index paths.
That means you need to update the itemQuantityField's text every time this runs, not just when you have a quantity above zero. Otherwise the cell will still have the text from when it was used previously at a different index path.
I've rewritten your if ([misc.itemQuantity doubleValue] > 0) {...} so that the text is set to nil if the itemQuantity is zero or less. The same could be achieved with an else clause.
BOOL validQuantity = [misc.itemQuantity doubleValue] > 0;
cell.itemQuantityField.text = validQuantity ? [misc.itemQuantity stringValue] : nil;