I’m new to this and I’m trying to get my head around the implementation of subclassing.
I understand the fundamental of creating a new file, and making it a subclass of whatever parent class (in this case I have chosen UITextField). I have created my own subclass, I have then gone and changed the class in the identity inspector of the appropriate UITextField objects to my new class, simply called “myTextField”. I have used code found elsewhere on SO to modify the presentation of the placeholder text, and it works fine (from the subclassed object).
I have (in the storyboard) made the viewController the delegate of my subclassed textFields.
And the appropriate methods fire as required, for example the textFieldShouldReturn method get’s activated on the “return” button within the view controllers .m file.
But these methods only fire on the viewcontroller, and not within my subclass. I’d like access to these, before the viewcontroller does anything with them.
Rephrasing, I still want it to fire as it should, but I would also like to do an action in the subclassed object but still have the full method fire in the main file. As an example, when the user hits the return, I want the subclassed object to handle the dropping of the keyboard directly, but then still having the viewcontrollers method firing as well.
This is just an example, probably a poor one, but the idea is, I don’t necessarily want to take away the functionality of the original method for the main viewcontroller, and I still want it to be the delegate; I just want the subclassed objects file to do some work as well. In this example it could be to drop the keyboard and play a ding sound. As I said, it’s an example and the action itself is irrelevant. But getting the action to perform where I want is the issue.
I know I haven’t properly got my head around subclassing, and I’m sorry in advance if I have missed something pretty basic.
I’d appreciate any pointers on this, thanks
It sounds as if you have a good grasp of subclassing but maybe a problem with delegation.
The point of a delegate is that there is one (only) object that does some work on behalf of another. When you get to the point of needing multiple objects to react to something, notifications are a better strategy.
There are two options I can see for your example. One would be to have the delegate explicitly call the method in your subclass. The other would be to have the delegate method post a custom notification and then any object that wanted to could react to that.
Choosing between those would depend on how general or specific you’d like the solution to be.