UICollectionCellView delegate not being fired - ios

Question

A UICollectionView I have created doesn't want to fire a custom cell delegate.
The cells are displaying, and the test button accepts presses.
I have debugged the code and the cell.delegate is being assigned self.
I have researched this on google and I have come up with nothing. I think my code is ok but I must be missing something?
I would really appreciate any help.
//HomeControllerDelegateTesting.swift
import UIKit
class HomeControllerDelegateTesting: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, PostCellOptionsDelegate {
var collectionView: UICollectionView! = nil
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView = UICollectionView(frame: self.view.bounds, collectionViewLayout: self.createLayout())
self.collectionView.register(PostCell.self, forCellWithReuseIdentifier: PostCell.reuseIdentifier)
self.collectionView.backgroundColor = .systemBackground
self.view.addSubview(collectionView)
self.collectionView.dataSource = self
self.collectionView.delegate = self
}
private func createLayout() -> UICollectionViewLayout {
let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
heightDimension: .fractionalHeight(1.0))
let item = NSCollectionLayoutItem(layoutSize: itemSize)
let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
heightDimension: .estimated(300))
let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize,
subitems: [item])
let section = NSCollectionLayoutSection(group: group)
let layout = UICollectionViewCompositionalLayout(section: section)
return layout
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: PostCell.reuseIdentifier, for: indexPath) as? PostCell else { fatalError("Cannot create cell") }
cell.postTextLabel.text = "Test"
cell.delegate = self
//Test to eliminiate the button accepts events
//cell.optionsButtons.addTarget(self, action: #selector(test), for: .touchUpInside)
return cell
}
#objc func handlePostOptions(cell: PostCell) {
print("123")
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
}
// PostCell.swift
import UIKit
protocol PostCellOptionsDelegate: class {
func handlePostOptions(cell: PostCell)
}
class PostCell: UICollectionViewCell {
static let reuseIdentifier = "list-cell-reuse-identifier"
var delegate: PostCellOptionsDelegate?
let usernameLabel: UILabel = {
let label = UILabel()
label.text = "Username"
label.font = .boldSystemFont(ofSize: 15)
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let postImageView: UIImageView = {
let control = UIImageView()
control.translatesAutoresizingMaskIntoConstraints = false
control.contentMode = .scaleAspectFill
control.clipsToBounds = true
return control
}()
let postTextLabel: UILabel = {
let label = UILabel()
label.text = "Post text spanning multiple lines"
label.font = .systemFont(ofSize: 15)
label.numberOfLines = 0
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
// private let optionsButtons: UIButton = {
// let control = UIButton.systemButton(with: #imageLiteral(resourceName: "post_options"), target: self, action: #selector(handleOptions))
// control.translatesAutoresizingMaskIntoConstraints = false
// return control
// }()
let optionsButtons: UIButton = {
let control = UIButton(type: .system)
control.setTitle("Test", for: .normal)
control.addTarget(self, action: #selector(handleOptions), for: .touchUpInside)
control.translatesAutoresizingMaskIntoConstraints = false
return control
}()
#objc fileprivate func handleOptions() {
print("Handle options button")
delegate?.handlePostOptions(cell: self)
}
override init(frame: CGRect) {
super.init(frame: frame)
setupComponents()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupComponents() {
self.optionsButtons.heightAnchor.constraint(equalToConstant: 50).isActive = true
let labelStack = UIStackView(arrangedSubviews: [optionsButtons])
labelStack.translatesAutoresizingMaskIntoConstraints = false
labelStack.axis = .horizontal
labelStack.alignment = .fill
labelStack.distribution = .fill
labelStack.isLayoutMarginsRelativeArrangement = true
labelStack.layoutMargins.left = 16
labelStack.layoutMargins.right = 16
labelStack.layoutMargins.top = 16
labelStack.layoutMargins.bottom = 16
let postTextLabelStack = UIStackView(arrangedSubviews: [postTextLabel])
postTextLabelStack.translatesAutoresizingMaskIntoConstraints = false
postTextLabelStack.axis = .vertical
postTextLabelStack.alignment = .fill
postTextLabelStack.distribution = .fill
postTextLabelStack.isLayoutMarginsRelativeArrangement = true
postTextLabelStack.layoutMargins.left = 16
postTextLabelStack.layoutMargins.right = 16
postTextLabelStack.layoutMargins.top = 16
postTextLabelStack.layoutMargins.bottom = 16
let stack = UIStackView(arrangedSubviews: [labelStack, postImageView, postTextLabelStack])
stack.translatesAutoresizingMaskIntoConstraints = false
stack.axis = .vertical
stack.alignment = .fill
stack.distribution = .fill
stack.backgroundColor = .blue
self.addSubview(stack)
//postImageView.heightAnchor.constraint(equalTo: postImageView.widthAnchor).isActive = true
stack.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
stack.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
stack.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
stack.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
}
}

Answer 1

Change your button declaration to this:
// make this a lazy var
lazy var optionsButtons: UIButton = {
let control = UIButton(type: .system)
control.setTitle("Test", for: .normal)
// add self. to the selector
control.addTarget(self, action: #selector(self.handleOptions), for: .touchUpInside)
control.translatesAutoresizingMaskIntoConstraints = false
return control
}()

Answer 2

The issue is that when the optionsButtons is created the self is still not initialized. Hence you need to make the button lazy var so that it could be loaded lazily when the optionsButtons is called and the UICollectionViewCell is initialized. Adding the target before self is initialized doesn't work.
To fix your issue, modify your optionsButtons declaration to lazy var, like this:
lazy var optionsButtons: UIButton = {
OR
Add the target after the UICollectionViewCell is initialized, like this:
override init(frame: CGRect) {
super.init(frame: frame)
optionsButtons.addTarget(self, action: #selector(handleOptions), for: .touchUpInside)
setupComponents()
}