Sending Custom TableViewCell Action to UITableView - ios

Question

Working on a small iOS app, and I made a custom tableview cell (and its own class) for my UITableView. Two of the things on the cell are "Add" and "Remove" button. When these are clicked, I need to update an array object that is in the UITableView, but because the table cell is a separate class, how can I send those changes over to the UITableView class?
For example, the code below is for my "remove" button on the cell:
- (IBAction)decrementItem:(id)sender {
int count = (int)[self.specificItemCount.text integerValue];
//Cannot have negative amount of food
if(count == 0) {
return;
} else {
count--;
self.specificItemCount.text = [NSString stringWithFormat:#"%i",count];
}
But I need to update my array object in my table view when that button is clicked, how can I do that?

Answer 1

Define a protocol on your cell class that your tableview class will implement. Here's an example: http://www.tutorialspoint.com/ios/ios_delegates.htm. Then set your tableview as a delegate on the cell (make sure to use a weak reference).

Answer 2

Use delegate or block.
If you only have one cell to operate, I recommend you use a block.
Define block, call when needed
// CustomCell.h
#interface CustomCell : UITableViewCell
#property (nonatomic, copy) void(^addBlock)(NSString *text);
#property (nonatomic, copy) void(^removeBlock)(NSString *text);
#end
// CustomCell.m
- (IBAction)decrementItem:(id)sender {
int count = (int)[self.specificItemCount.text integerValue];
//Cannot have negative amount of food
if(count == 0) {
return;
} else {
count--;
self.specificItemCount.text = [NSString stringWithFormat:#"%i",count];
}
if (removeBlock) {
removeBlock(self.specificItemCount.text)
}
}
Write the operation you need inside
// VC.m
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath == customIndexPath) {
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:customIdentifier forIndexPath:indexPath];
__weak typeof(self)weakSelf = self;
cell.removeBlock = ^(NSString *text) {
__strong typeof(weakSelf)strongSelf = weakSelf;
// operation
};
cell.addBlock = ^(NSString *text) {
__strong typeof(weakSelf)strongSelf = weakSelf;
// operation
};
return customCell;
}
// ······
}