Question

How do I add custom data while specifying a target in a UIButton?

id data = getSomeData();
[button addTarget:self 
           action:@selector(buyButtonTapped:event:) 
 forControlEvents:UIControlEventTouchUpInside];

I want the buyButtonTapped function to look like:

(void) buyButtonTapped: (UIButton *) button event: (id) event data: (id) data

Answer 1

not possible. the action that is triggered by an UIControl can have 3 different signatures.

- (void)action
- (void)action:(id)sender
- (void)action:(id)sender forEvent:(UIEvent *)event

None of them allows you to send custom data.

---

Depending on what you want to do you can access the data in different ways.

For example if the button is in a UITableView you could use something like this:

- (IBAction)buttonPressed:(UIButton *)sender {
    CGPoint buttonOriginInTableView = [sender convertPoint:CGPointZero toView:tableView];
    NSIndexPath *indexPath = [tableView indexPathForRowAtPoint:buttonOriginInTableView];
    NSData *customData = [myDataSource customDataForIndexPath:indexPath];
    // do something
}

There is always a way to get the data without passing it to the button.