Segue in a UICollectionView embedded in a UITableviewCell, Swift - ios

Question

I have made a UICollectionView inside a UITableViewCell and it works pretty Fine. My only Problem is, that I can't perform a Segue on didSelectItemAt Method to another ViewController.
I know I have to perform it from the TableViewController,I made a segue on the Storyboard and I tried multiple possibilities but for some reasons it doesn't work.
Here my TableviewController:
import UIKit
import RealmSwift
import SwiftyJSON
class HomeVTwoTableViewController: UITableViewController {
let realm = try! Realm()
let headers = ["1","2","3"]
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
self.tableView.separatorStyle = .none
}
//MARK: Custom Tableview Headers
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return headers[section]
}
//MARK: DataSource Methods
override func numberOfSections(in tableView: UITableView) -> Int {
return headers.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
//Choosing the responsible PrototypCell for the Sections
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellBig", for: indexPath) as! HomeVTwoTableViewCell
cell.update()
return cell
} else {
return UITableViewCell()
}
}
// This on of my tries to perform a segue
func liveCellSelected() {
performSegue(withIdentifier: "showChat", sender: nil)
}
}
And here my TableViewCell with the embedded CollectionView:
import UIKit
import RealmSwift
class HomeVTwoTableViewCell: UITableViewCell{
var liveCommunities: Results<Community>?
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
collectionView.delegate = self
collectionView.dataSource = self
}
}
extension HomeVTwoTableViewCell:
UICollectionViewDataSource,UICollectionViewDelegate {
func numberOfSections(in collectionView: UICollectionView) -> Int
{
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return(liveCommunities?.count)!
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCellBig", for: indexPath) as? HomeVTwoCollectionViewCell else
{
fatalError("Cell has wrong type")
}
//removes the old image
cell.imageView.image = UIImage(named: "No Image")
cell.titleLbl.text = nil
//set url and Picture
url = (liveCommunities?[indexPath.row].pictureId)!
let name : String = (liveCommunities?[indexPath.row].communityName)!
let channelName : String = (liveCommunities?[indexPath.row].channelName)!
cell.titleLbl.text = name
cell.senderLbl.text = channelName
cell.imageView.downloadedFrom(link :"someSecretUrl")
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedCommunity = (liveCommunities?[indexPath.row].communityId)!
HomeVTwoTableViewController().liveCellSelected()
}
}
I found another question with a similar theme, but couldn't implement a delegate Protocol without creating problems with the already existing delegates.
Maybe it`s an obvious mistake but I can't see it.
Thanks in advance.

Answer 1

You're instantiating a new instacne of your home controller with this:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedCommunity = (liveCommunities?[indexPath.row].communityId)!
HomeVTwoTableViewController().liveCellSelected()
}
what you should do is to make it via a delegate, or you move your collectionview delegate to the main controller
protocol CellCollectionViewDelegate: class{
func didselect()
}
and you implement the delegate in cell and your home controller

Answer 2

May be you can create a variable to handle this. You can do optional also.
class HomeVTwoTableViewCell: UITableViewCell{
var liveCommunities: Results<Community>?
#IBOutlet weak var collectionView: UICollectionView!
var didSelectAction: () -> Void // add your action here
Here you can call to this function
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedCommunity = (liveCommunities?[indexPath.row].communityId)!
HomeVTwoTableViewController().liveCellSelected()
didSelectAction() // Invoque your action
}
//On the cell creator, add the navigation or logic when you want to tap the cell
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellBig", for: indexPath) as! HomeVTwoTableViewCell
cell.update()
cell.didSelectAction = {
// add here your navigation
}
return cell
} else {
return UITableViewCell()
}
}

Answer 3

Ok as it seems there are two Solutions to this Problem.
One is via a Variable and one via a delegate. As I know the delegate one is more common.
Solution 1 with Variable:
Here my TableviewController:
import UIKit
class TableViewController: UITableViewController {
let headers = ["1","2","3"]
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return headers.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellBig", for: indexPath) as! HomeVTwoTableViewCell
//Fill function, insert Navigation
cell.didSelectAction = {
self.performSegue(withIdentifier: "testSegue", sender: nil)
}
return cell
}
And here my TableViewCell with the embedded CollectionView:
import UIKit
class HomeVTwoTableViewCell: UITableViewCell{
var liveCommunities: Results<Community>?
//Instantiate function
var didSelectAction: () -> Void = {}
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
collectionView.delegate = self
collectionView.dataSource = self
}
}
extension HomeVTwoTableViewCell:
UICollectionViewDataSource,UICollectionViewDelegate {
func numberOfSections(in collectionView: UICollectionView) -> Int
{
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return(liveCommunities?.count)!
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCellBig", for: indexPath) as? HomeVTwoCollectionViewCell else
{
fatalError("Cell has wrong type")
}
//removes the old text
cell.titleLbl.text = nil
cell.senderLbl.text = nil
let name : String = (liveCommunities?[indexPath.row].communityName)!
let channelName : String = (liveCommunities?[indexPath.row].channelName)!
cell.titleLbl.text = name
cell.senderLbl.text = channelName
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedCommunity = (liveCommunities?[indexPath.row].communityId)!
// Invoque your action
didSelectAction()
}
}
Solution 2 with Delegate and Protocol:
Here my TableviewController:
import UIKit
class TableViewController: UITableViewController {
let headers = ["1","2","3"]
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return headers.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellBig", for: indexPath) as! HomeVTwoTableViewCell
//Add delegate
cell.delegate = self
return cell
}
//Add Extension with Navigation
extension HomeVTwoTableViewController: CellCollectionViewDelegate {
func didSelect() {
performSegue(withIdentifier: "showChat", sender: nil)
}
}
And here my TableViewCell with the embedded CollectionView:
import UIKit
//Create a delegate protocol
protocol CellCollectionViewDelegate: class{
func didSelect()
}
class HomeVTwoTableViewCell: UITableViewCell{
var liveCommunities: Results<Community>?
//Add a delegate property
weak var delegate: CellCollectionViewDelegate?
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
collectionView.delegate = self
collectionView.dataSource = self
}
}
//Adopt and implement the Delegate Protocol
extension HomeVTwoTableViewCell:
UICollectionViewDataSource,UICollectionViewDelegate {
func numberOfSections(in collectionView: UICollectionView) -> Int
{
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return(liveCommunities?.count)!
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCellBig", for: indexPath) as? HomeVTwoCollectionViewCell else
{
fatalError("Cell has wrong type")
}
//removes the old text
cell.titleLbl.text = nil
cell.senderLbl.text = nil
let name : String = (liveCommunities?[indexPath.row].communityName)!
let channelName : String = (liveCommunities?[indexPath.row].channelName)!
cell.titleLbl.text = name
cell.senderLbl.text = channelName
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedCommunity = (liveCommunities?[indexPath.row].communityId)!
//call delegate method
delegate?.didSelect()
}
}
I tried to sum up the Solutions from
Abdoelrhman Mohamed and Alexkater and write it out in detail.
Tell me if something is wrong or left out.