Delegate Function Not Being Called - ios

Question

So I am trying to use protocols and delegates to connect two functions so I can perform some operation on a variable a collectionView in this case in a different file.
import Foundation
import UIKit
protocol EventCollectionCellDelegate: NSObjectProtocol {
func setupCollectionView(for eventCollectionView: UICollectionView?)
}
class EventCollectionCell:UICollectionViewCell {
weak var delegate: EventCollectionCellDelegate?
var eventArray = [EventDetails](){
didSet{
self.eventCollectionView.reloadData()
}
}
var enentDetails:Friend?{
didSet{
var name = "N/A"
var total = 0
seperator.isHidden = true
if let value = enentDetails?.friendName{
name = value
}
if let value = enentDetails?.events{
total = value.count
self.eventArray = value
seperator.isHidden = false
}
if let value = enentDetails?.imageUrl{
profileImageView.loadImage(urlString: value)
}else{
profileImageView.image = #imageLiteral(resourceName: "Tokyo")
}
self.eventCollectionView.reloadData()
setLabel(name: name, totalEvents: total)
}
}
let container:UIView={
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
view.layer.cornerRadius = 16
view.layer.borderColor = UIColor.lightGray.cgColor
view.layer.borderWidth = 0.3
return view
}()
//profile image view for the user
var profileImageView:CustomImageView={
let iv = CustomImageView()
iv.layer.masksToBounds = true
iv.layer.borderColor = UIColor.lightGray.cgColor
iv.layer.borderWidth = 0.3
iv.translatesAutoresizingMaskIntoConstraints = false
return iv
}()
//will show the name of the user as well as the total number of events he is attending
let labelNameAndTotalEvents:UILabel={
let label = UILabel()
label.textColor = .black
label.translatesAutoresizingMaskIntoConstraints = false
label.numberOfLines = 0
return label
}()
let seperator:UIView={
let view = UIView()
view.backgroundColor = .lightGray
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
//collectionview that contains all of the events a specific user will be attensing
let flow = UICollectionViewFlowLayout()
lazy var eventCollectionView = UICollectionView(frame: .zero, collectionViewLayout: flow)
// var eventCollectionView:UICollectionView?
override init(frame: CGRect) {
super.init(frame: frame)
self.setUpCell()
self.setupCollectionView(for: eventCollectionView)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupCollectionView(for eventCollectionView: UICollectionView?){
delegate?.setupCollectionView(for: eventCollectionView)
}
}
This is the file that creates a collectionViewCell with a collectionView in it. I am trying to perform some operation on that collectionView using the delegate pattern. My problem is that the delegate function is never called in the accompanying viewController. I feel like I have done everything right but nothing happens in the accompanying vc. Anyone notice what could possibly be wrong.
I have shown the code for the VC below
class FriendsEventsView: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout,EventCollectionCellDelegate {
var friends = [Friend]()
var followingUsers = [String]()
var height:CGFloat = 0
var notExpandedHeight : CGFloat = 50
var isExpanded = [Bool]()
//so this is the main collectonview that encompasses the entire view
lazy var mainCollectionView:UICollectionView={
// the flow layout which is needed when you create any collection view
let flow = UICollectionViewFlowLayout()
//setting the scroll direction
flow.scrollDirection = .vertical
//setting space between elements
let spacingbw:CGFloat = 5
flow.minimumLineSpacing = spacingbw
flow.minimumInteritemSpacing = 0
//actually creating collectionview
let cv = UICollectionView(frame: .zero, collectionViewLayout: flow)
//register a cell for that collectionview
cv.register(EventCollectionCell.self, forCellWithReuseIdentifier: "events")
cv.translatesAutoresizingMaskIntoConstraints = false
//changing background color
cv.backgroundColor = .white
//sets the delegate of the collectionView to self. By doing this all messages in regards to the collectionView will be sent to the collectionView or you.
//"Delegates send messages"
cv.delegate = self
//sets the datsource of the collectionView to you so you can control where the data gets pulled from
cv.dataSource = self
//sets positon of collectionview in regards to the regular view
cv.contentInset = UIEdgeInsetsMake(spacingbw, 0, spacingbw, 0)
return cv
}()
lazy var eventCollectionView:UICollectionView={
let flow = UICollectionViewFlowLayout()
flow.scrollDirection = .vertical
let spacingbw:CGFloat = 5
flow.minimumLineSpacing = 0
flow.minimumInteritemSpacing = 0
let cv = UICollectionView(frame: .zero, collectionViewLayout: flow)
//will register the eventdetailcell
cv.translatesAutoresizingMaskIntoConstraints = false
cv.backgroundColor = .white
cv.register(EventDetailsCell.self, forCellWithReuseIdentifier: "eventDetails")
cv.delegate = self
cv.dataSource = self
cv.contentInset = UIEdgeInsetsMake(spacingbw, 0, spacingbw, 0)
cv.showsVerticalScrollIndicator = false
cv.bounces = false
return cv
}()
func setupCollectionView(for eventCollectionView: UICollectionView?) {
print("Attempting to create collectonView")
eventCollectionView?.backgroundColor = .blue
}
//label that will be displayed if there are no events
let labelNotEvents:UILabel={
let label = UILabel()
label.textColor = .lightGray
label.translatesAutoresizingMaskIntoConstraints = false
label.numberOfLines = 0
label.font = UIFont.italicSystemFont(ofSize: 14)
label.text = "No events found"
label.isHidden = true
return label
}()
override func viewDidLoad() {
super.viewDidLoad()
//will set up all the views in the screen
self.setUpViews()
self.navigationItem.rightBarButtonItem = UIBarButtonItem(image: #imageLiteral(resourceName: "close_black").withRenderingMode(.alwaysOriginal), style: .done, target: self, action: #selector(self.goBack))
}
func setUpViews(){
//well set the navbar title to Friends Events
self.title = "Friends Events"
view.backgroundColor = .white
//adds the main collection view to the view and adds proper constraints for positioning
view.addSubview(mainCollectionView)
mainCollectionView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
mainCollectionView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
mainCollectionView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: 0).isActive = true
mainCollectionView.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 0).isActive = true
//adds the label to alert someone that there are no events to the collectionview and adds proper constrains for positioning
mainCollectionView.addSubview(labelNotEvents)
labelNotEvents.centerYAnchor.constraint(equalTo: mainCollectionView.centerYAnchor, constant: 0).isActive = true
labelNotEvents.centerXAnchor.constraint(equalTo: mainCollectionView.centerXAnchor, constant: 0).isActive = true
//will fetch events from server
self.fetchEventsFromServer()
}
// MARK: CollectionView Datasource for maincollection view
//woll let us know how many cells are being displayed
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
print(friends.count)
isExpanded = Array(repeating: false, count: friends.count)
return friends.count
}
//will control the size of the cell that is displayed in the containerview
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
height = 100
let event = friends[indexPath.item]
if let count = event.events?.count,count != 0{
height += (CGFloat(count*40)+10)
}
return CGSize(width: collectionView.frame.width, height: height)
}
//will do the job of effieicently creating cells for the eventcollectioncell
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "events", for: indexPath) as! EventCollectionCell
cell.delegate = self
cell.enentDetails = friends[indexPath.item]
cell.eventCollectionView = eventCollectionView
return cell
}
}
I have cut the code down to what I believe is needed to answer the question for simplicity. Any help is appreciated

Answer 1

You set delegate after setupCollectionView. In your case, you can't call setupCollectionView before you set delegate, because setupCollectionView called in init