Vfrdtyky

I make a request to the server for fetching data, then set its data to my array for dealing with TableView.

Sometimes happens issue when one cell or few cells is froze despite the fact that server response is an empty dataSource array is an empty too, but cells stacks anyway. And still on the screen till I closed. Also tableView contentOffset is changed:

The screenshot shows froze tableViewCell. But dataSource array is an empty, numberOfRowsInSection in section also equal to 0.

Some details:

• 
  tableView.reloadData() is called from the main thread;


• ViewController lie in TabBarViewController;


• I inspect mine model object class on Retain cycle, seems everything is fine;


• I use xib for the cell. The cell has a custom content view. All IBOutlets in Cell class has weak references.

Please, help me to understand where I'm wrong

EDIT:

extension ViewController: UITableViewDataSource {



    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        guard let numberOfRowsInSection = items?.count else {

            messageLabel?.text = messageText

            return 0

        }



        return numberOfRowsInSection

    }



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



        guard let cell = tableView.dequeueReusableCell(withIdentifier: "Identifier", for: indexPath) as? CustomTableViewCell else { return UITableViewCell() }



        // Cell settings



        return cell



    }

}

My guess is that you are missing data source method

optional func numberOfSections(in tableView: UITableView) -> Int

https://developer.apple.com/documentation/uikit/uitableviewdatasource/1614860-numberofsections

The number of sections in tableView. The default value is 1.

This should break your implementation when you have 0 items in your array. Based on your structure it could look similar to

override func numberOfSections(in tableView: UITableView) -> Int {

    guard let arr = items else { return 0 }

    return arr.count == 0 ? 0 : 1

}

The problem is here:

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



    guard let cell = tableView.dequeueReusableCell(withIdentifier: "Identifier", for: indexPath) as? CustomTableViewCell else { return UITableViewCell() }



    // Cell settings



    return cell



}

You are returning a cell without dequeueing it.

If you instantiate a cell yourself the TableView doesn't have control over it, so it is not able to reuse it after you update your data source.

Please change your code like this:

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



    let cell = tableView.dequeueReusableCell(withIdentifier: "Identifier", for: indexPath) as! CustomTableViewCell



    // Cell settings



    return cell



}

But also make sure you are registering the cell before that, in your viewDidLoad probably.

Something like:

tableView.register(CustomTableViewCell.self, forCellReuseIdentifier:"Identifier")