Swift 3: Tableview datasource methods "Overriding non-open instance method outside of its defining module" error

Question

I have an open BaseViewController class in core framework that has tableview datasource methods implemented. Let's say I've another class (outside the module) ClassA with BaseViewController as it's superclass. When I try to override tableview datasource methods, it's throwing this error Overriding non-open instance method outside of its defining module.

BaseViewController looks like this

open class BaseViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

...

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 0
}

public func numberOfSections(in tableView: UITableView) -> Int {
    return 0
}

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    return UITableViewCell()
  }
}

ClassA

import CustomCoreFramework

class ClassA : BaseViewController {

// throws an error
public override func numberOfSections(in tableView: UITableView) -> Int {
    return tableViewListItems.count
}

}

I suppose the open class methods should be accessible outside the module. I tried changing the tableview methods access specifiers to public and different combinations but nothing seems to work.

may be because methods are marked public try removing public once and check, not sure though haven't tried this before. — Tushar Sharma, Aug 18 '17 at 19:22
You have to inherit `BaseViewController` – as the name seems to imply – from **UIViewController** rather than from `UITableViewDelegate` — vadian, Aug 18 '17 at 19:23
@vadian Yes I'm doing that, just forgot to put it in the post. I've updated the post. Please check. — Srujan Simha, Aug 18 '17 at 19:30

Xvolks · Accepted Answer · 2017-08-18T20:53:16.710

11

The BaseViewController’s methods should be declared open. This is discuss in the thread in reference.

See What is the 'open' keyword in Swift?

edited Aug 18 '17 at 20:53

answered Aug 18 '17 at 19:33

Xvolks

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I tried that before, it didn't work but now it did. I don't know why!! I'm glad that it worked and also pissed because it didn't work before. Thanks anyway. – Srujan Simha Aug 18 '17 at 19:41

Swift 3: Tableview datasource methods "Overriding non-open instance method outside of its defining module" error

1 Answers1