How to implement a specific multiple inheritance scheme in objective-c

The UITableViewController class does a few things for you:

1. It creates a UITableView as its view, if you haven't specified its view some other way (by using a XIB or a storyboard or by overloading loadView or by assigning to its view property directly). It is easy to do this yourself.

2. It prevents the current input field from being hidden behind the keyboard when the keyboard appears. You can also do this yourself. It's not terribly hard. Apple documents the process in “Moving Content That Is Located Under the Keyboard” in the Text, Web, and Editing Programming Guide for iOS and there are also many Q&As covering it here on stack overflow.

3. It does some other incidental things listed in the “Overview” section of the * UITableViewController Class Reference*, all of which are trivial to implement yourself.

4. If you're using a storyboard, it allows you to define static table view cells in the storyboard. This is the only feature of UITableViewController that I can think of that you cannot easily replicate in your own UIViewController subclass.

If you don't need #4, then you should use your solution #2 (just make an A subclass).

If you need #3, you could use your solution #4. But it would probably be better to factor that functionality out of A into a separate helper class Z, and give both A and D an instance variable (or property) of class Z.

You do not need a UITableViewController sublcass to handle UITableView's delegate and datasource methods. All you have to do is have your class implement UITableViewDelegate and UITableViewDataSource and then implement the proper methods (ie the ones that a UITableViewController would include).

For example, you could have:

@interface D : A <UITableViewDelegate,UITableViewDataSource>

To declare your UIViewController D as a subclass of A that implements UITableView's dataSource and delegate.

Then, when you create your UITableView in class D, do:

tableView.delegate = self;
tableView.dataSource = self;

Once you have done this, all you have to do is implement the dataSource and delegate methods that you need in class D and your UITableView will be populated.

For example, you could have:

D.m

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [self.data count]; //self.data is an array the UITableView is populated from.
}

//...etc implement other methods.

The question is not clear.

If A is already a UIViewController then it has a well known property (view) that points to its one and only one view. If D is to be a subclass of A, it can have one and only one view. If what you describe is the case, you have conflicting requirements for D. I would guess it would be better to add a new class E, and have it aggregate A and D, but that's just a guess based on zero information about your actual requirement.

Objective C is not C++ where the 'D' part of the class can own its own 'view' member.