UITableView cellForRowAt method is not getting executed-CodePudding

extension ArticlesViewController {
    func setup() {
        self.navigationController?.navigationBar.prefersLargeTitles = true
    
    newtworkManager?.getNews { [weak self] (results) in
        switch results {
        case .success(let data):
            self?.articleListVM = ArticleListViewModel(articles: data.article!)
            // For testing
            print(self?.articleListVM.articles as Any)
            
            DispatchQueue.main.async {
                self?.tableView.reloadData()
            }
        case .failure(let error):
            print(error.localizedDescription)
        }
    }
}

Now, while debugging, I am receiving data successfully and printing it out. However, I realized the cellForRowAt function is not being executed which is causing the data not showing on the table. I cannot see any issue, but the run time disagrees of course.

extension ArticlesViewController {
override func numberOfSections(in tableView: UITableView) -> Int {
    return self.articleListVM == nil ? 0 : self.articleListVM.numberOfSections
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.articleListVM.numberOfRowsInSection(section)
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    guard let cell = tableView.dequeueReusableCell(withIdentifier: "ArticleTableViewCell", for: indexPath) as? ArticleTableViewCell else {
        fatalError("ArticleTableViewCell not found")
    }
    
    let articleVM = self.articleListVM.articleAtIndex(indexPath.row)
    cell.titleLabel.text = articleVM.title
    cell.abstractLabel.text = articleVM.abstract
    return cell
}

}

Why do you think this method is not getting triggered? Note that my UITableView and UITableViewCell on the storyboard are connected respectively to my code. I see no reason why it is not loading the data.

CodePudding user response：

Confirm ArticlesViewController to UITableViewDelegate & UITableViewDataSource protocol & remove override for functions. Example:

extension ArticlesViewController: UITableViewDelegate, UITableViewDataSource {
    func numberOfSections(in tableView: UITableView) -> Int {
        return self.articleListVM == nil ? 0 : self.articleListVM.numberOfSections
    }

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

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

Also make sure you have connected your tableview via storyboard/code.

tableView.dataSource = self
tableView.delegate = self

CodePudding user response：

How have you layed out the views, programmatically or via Storyboard?

If done via Storyboard, make sure to connect the IBOutlet properly(check for typos etc), assign delegate & datasource to the tableviews and conform to the protocols.

If done programmatically, make sure you add the tableview to the parent view as a subview, lay out the tableview by either adding constraints(make sure to set tableview.translatesAutoresizingMaskIntoConstraints = false) or by setting frames.

CodePudding user response：

My main issue was with the global variable newtworkManager And as you can see in code:

newtworkManager?.getNews {...}

The solution was that I deleted this global variable and replaced it with the following:

NetworkManager().getNews { ...}

After that, cellForRowAt method was working fine and data cells were displayed on the UITableView.