Swift: How to display a CollectionView inside a TableViewCell Programmatically

Question

This code displays a collectionView inside a tableViewCell, where both have been added inside the StoryBoard:

class TableViewCell: UITableViewCell {

    @IBOutlet weak var collectionView: UICollectionView!
    override func awakeFromNib() {
        super.awakeFromNib()
       collectionView.delegate = self
        collectionView.dataSource = self
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }

}

extension TableViewCell:  UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 1
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionViewCell", for: indexPath)
        return cell
    }
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: 139, height: 64)
    }

In my app, I am creating the CollectionView And the TableView programmatically.

Creating a collectionView programmatically:

class collectionViews {
     static func collectionViewOne() -> UICollectionView {
        let flowLayout = CarouselFlowLayout()
        let collectionViewOne = UICollectionView(frame: CGRect(x: 106, y: 313, width: 1708, height: 300), collectionViewLayout: flowLayout)
        return collectionViewOne
    }
}

Instantiating collectionView inside tableViewCell:

class TableViewCell2: UITableViewCell {
    var moviesItems: [movieItem] = []
    let cellIdentifier = "movieCardCell"
    let collectionViewOne = collectionViews.collectionViewOne()

    private func setupCollectionView(){

        collectionViewOne.delegate = self
        collectionViewOne.dataSource = self
        collectionViewOne.backgroundColor = UIColor (hex: "444A64")
         collectionViewOne.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "MyCell")
                 let nib = UINib(nibName: "movieCardCell", bundle: nil)
        collectionViewOne.register(nib, forCellWithReuseIdentifier: cellIdentifier)

    }
}

// These functions never get called
 extension TableViewCell:  UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
 func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
     print("INSIDE TableViewCell2.collectionView 1")
     return 1
 }
 
 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
     let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionViewCell", for: indexPath)
     print("INSIDE TableViewCell2.collectionView 2")
     return cell
 }
 
 func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
     // For some reason he chose the measures of collectionViewCell and substracted 2
     print("INSIDE TableViewCell2.collectionView 3")
     return CGSize(width: 139, height: 64)
 }
 }

NOTICE: The delegate functions never get called. So the collectionView was never added to the tableViewCell?

Creating TableView Programmatically:

class sectionTableCell: TableViewCell2 {
}
class MoviesViewController4: UIViewController {
    let tableView = UITableView()
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor (hex: "444A64")
        tableView.delegate = self
        tableView.dataSource = self
         tableView.register(sectionTableCell.self, forCellReuseIdentifier: "tableViewCell")
        displayTableView2()
    }

    func displayTableView2() {
        self.view.addSubview(tableView)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
    }
}


extension MoviesViewController4: UITableViewDelegate, UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 1
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        guard let cell =
            tableView.dequeueReusableCell(withIdentifier: "tableViewCell", for: indexPath) as? sectionTableCell
          else {
                fatalError("Unable to create explore table view cell")}
        return cell
    }
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 140
    }
}

So the question is: How to add the collectionView that I programmatically created to the tableViewCell that I also created programmatically?

Answer 1

As far as I can see, you don't call setupCollectionView() method anywhere in your code. You should do that in the init method of the UITableViewCell. Add this code to your cell class:

override init(frame: CGRect) {
    super.init(frame: frame)
    setupCollectionView()
}

required init?(coder: NSCoder) {
    super.init(coder: coder)
    setupCollectionView()
}