How to Navigate to another ViewController from Collectionview cell which is inside Tableview cell using delegate?

Question

I am trying to navigate to another ViewController from Collectionview cell which is inside Tableview cell.

I am trying to achieve using delegate method but it's not navigating to intended viewcontroller.

Here is code that i have developed so far. I am using xib setup here.

//  ViewController.swift

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate,CustomTableViewCellDelegate {

    @IBOutlet weak var tableView: UITableView!
    var customTableViewCell = CustomTableViewCell()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        customTableViewCell.delegate = self
        
        tableView.delegate = self
        tableView.dataSource = self
        
        self.tableView.register(UINib(nibName: "CustomTableViewCell", bundle: nil), forCellReuseIdentifier: "CustomTableViewCell")
    }

    override func viewWillAppear(_ animated: Bool) {
        navigationController?.navigationBar.barTintColor = UIColor.black
        navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: UIColor.white]
        self.navigationController?.navigationBar.tintColor = UIColor(red: 211/255, green: 86/255, blue: 50/255, alpha: 1.0)
    }
    
    //Delegate method
    func passTheCurrent(tableIndex: Int, collectionViewIndex: Int) {
        print("collectionViewIndex \(collectionViewIndex)")
        let selectpile = ObjectSceneViewCtrl()
        self.navigationController?.pushViewController(selectpile, animated: true)
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 3
    }
    
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 120
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let customCell = tableView.dequeueReusableCell(withIdentifier: "CustomTableViewCell", for: indexPath) as! CustomTableViewCell
        return customCell
    }

}

Here is CustomTableViewCell where i am defining delegate methods. I am calling delegate function inside collectionview didSelectItemAt method. But delegate is returning nil.

import UIKit

protocol CustomTableViewCellDelegate {
    func passTheCurrent(tableIndex: Int, collectionViewIndex: Int)
}

class CustomTableViewCell: UITableViewCell {

    @IBOutlet weak var collectionView: UICollectionView!
   
    var delegate: CustomTableViewCellDelegate?

    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
        self.collectionView.dataSource = self
        self.collectionView.delegate = self
        self.collectionView.register(UINib.init(nibName: "CollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "CollectionViewCell")
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
        // Configure the view for the selected state
    }
    
}

extension CustomTableViewCell : UICollectionViewDelegate {}

extension CustomTableViewCell : UICollectionViewDataSource {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
          return 15
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath as IndexPath) as! CollectionViewCell
        return cell
    }
    
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        delegate?.passTheCurrent(tableIndex: 0, collectionViewIndex: indexPath.item)
    }

}

When i set break point, delegate is returning nil. What is wrong with this setup. please help me out.

user_7127047 · Answer

do the following simple steps this may helps you

1- in your cellForRowAt method assign delegate to your cell

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
    let customCell = tableView.dequeueReusableCell(withIdentifier: "CustomTableViewCell", for: indexPath) as! CustomTableViewCell
    customCell.delegate = self
    return customCell
    
}

2- in your CustomTableViewCell class update your didSelectItemAt method with following code

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    if let del = self.delegate
    {
        del.passTheCurrent(tableIndex: 0, collectionViewIndex: indexPath.item)
    }
}

Basically what we are doing now 1st we assigning delegate to cell on each index. 2nd in table cell class first we checking is delegate confirmed then pass the data to parent controller class.

How to Navigate to another ViewController from Collectionview cell which is inside Tableview cell using delegate?

1 Answers