How to Subclass Uitableviewcontroller in Swift

How to subclass an UIViewController with UITableViewDelegate in many subclasses

What you're trying to do doesn't really work that way. The @IBOutlets are all connected through the Storyboard - but they don't "flow through" in the pattern you're hoping to use.

You can do it - in a way. Take a look a the discussion and answers in this SO post: How to subclass custom UIViewController in Swift?

Alternatively, if you're goal is to use a "common" table view controller - but allow customization - you can create separate UITableViewDelegate and UITableViewDataSource files, plus separate visually designed cells, and then assign them via code as desired.

Subclassing UITableViewController in Swift

Maddening, isn't it? But the error message tells you what to do: if you are going to call super.init(style:), then you must also implement init(nibName:bundle:), even if all you do there is to call super:

override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
    super.init(nibName:nibNameOrNil, bundle:nibBundleOrNil)
}

This, however, raises the question of what to do about properties. Swift won't let you implement init(nibName:bundle:) unless it initializes all uninitialized properties.

One obvious solution is to make your properties Optionals; now the implementation shown above is legal. In init(scheduleController:), you will have to initialize your properties after calling super.init.
Less dramatically, make your property a var but not an Optional. Now initialize it multiple times: before super.init in all your initializers, and also after super.init in your init(scheduleController:).

None of those, however, are the solution I use in my own code. In my code, I do not call super.init(style:), as you are doing — I call super.init(nibName:bundle:) instead. This works because:

The default style is .Plain, which is what you want
Even if what you want is .Grouped, you can specify that in the associated nib file

The big advantage of this approach is that it permits your properties to be a non-Optional let, which is probably what you really would like to do.

Subclass UITableView in Swift

You're probably looking to override numberOfSections instead of numberOfSectionsInTableView:, which is a method on the UITableViewDataSource protocol. However, I believe it's more wise to create your own subclass of UITableViewController or your class conforming to UITableViewDataSource and set it as your table view's delegate rather than of the table view itself. Subclassing UIView and its descendants is usually reserved for customizing view-specific functionality and attributes, such as adding custom drawing or custom touch handling.

How to properly override init() for UITableViewController subclass?

Problem is that if inside guard value isn't assigned, super.init(...) isn't called and non-optional variables aren’t assigned as well. But you want to throw fatalError in else {...} so calling super.init(...) here wouldn’t make any sense.

So first call super.init(...) and then do other stuff

override init(...) {
    super.init(...)
    ... // do other stuff
}

then make sure that you assign all non-optional global variables before you call super.init(...). If don't (like your case), make these variables optional

var variable: Type?

How can I subclass a UITableView?

I think, you should still go with a Controller class. I expect subclassing UITableView to be tedious work — if possible with reasonable amount at all.

There is no problem to have UIViewController/NoViewController implemented the delegate and datasource and yet assign another controller to a specific tableView. note, that the datasource and delegate don't need to be subclasses of UITableViewController.

have a look at this answer: Implement Delegate at Run Time?

My UITableView does not delegate to its view controller, so that's not the problem.

You have to have to use delegate and datasource, that is how TableViews are filled and configured. otherwise you will have to overwrite every method of UITableView — including private ones, a no-go if you want into AppStore. Recreating UITableView without subclassing it would be even easier.