Question

How can I tell programmatically if a IBAction has been called by code or by user action.

Eg
I have a method, -(IBAction)someMethodWithIts:(id)sender
which I have linked to a valueChanged on a UISegmentedControl.

It can be called by,

1. User changing segment
2. setting the selectedIndex in code
3. calling [self someMethodWithIts:foo];

Is there a way to distinguish if the call has come from the first way?

Cheers

Sam

Answer 1

If you can pass nil as the sender (which is traditional) and use that to indicate it was sent programmatically, that’s ok. But anything else I believe is too fragile and you should break up the code like this:

- (void)someMethod {
  // stuff shared by everyone
}

- (IBAction)someMethodWithIts:(id)sender {
  // stuff specific to IBAction
  [self someMethod];
}

If you really want a sender, then you can do it this way:

- (void)someMethodWithIts:(id)sender triggeredByUser:(BOOL)isUser {
}

- (IBAction)someMethodWithIts:(id)sender {
  [self someMethodWithIts:sender triggeredByUser:YES];
}

But in general, if you want the IBAction to be different than programatic changes, then don’t wire programatic changes to the IBAction.