Question

Say that self is the object myObject and I do something like [self setDelegate:theDelegate]

From inside theDelegate how can I access myObject ?

Answer 1

You can’t. Delegate doesn’t need to know about objects it’s delegating. Most of delegate methods have a parameter that holds a pointer to instance which called the delegate, in case delegate needs to interact with the delegated object upon receiving a message from it. That’s all you should ever do.

Example – change a background color of UITextField instance when it’s done with editing:

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    // textField is a pointer to an instance that called us (the delegate)
    textField.backgroundColor = [UIColor redColor];
}