How to Pass Collection View Data to a New View Controller - xcode

Question

I am going try be as specific as possible.
What I am trying to achieve is to have one view controller which has a collection view in it and when the user clicks on of the collection view cells, it then sends the user to another view controller which has another collection view however the items displayed in the second collection view will change depending on which collection view cell the user previously tapped. I am also using CoreData to do this. With CoreData, the task is an entity and has attributes like name etc. Will I have to change this or have a relationship between the 2 collection views?
The reason for me wanting to do this is because I am creating a productivity app for iOS and the first view controller with a collection view will be where the user can create projects, within these projects which will be displayed in a collection view, the user can then tap on one of the cells and go to the next view controller and begin to create tasks specific to that project.
How can I keep the tasks stored in a specific collection view cell and have the user create different tasks in other projects. It is sort of like Wunderlist. If anybody is confused at what I am trying to do, I can ellaborate more.
This is one of my view controllers where the data from the 'create item view controller' gets sent to via CoreData and displays it in a collection view, hope it helps:
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
#IBOutlet weak var myCollView: UICollectionView!
#IBAction func addCore(_ sender: UIButton) {
}
var tasks : [Task] = []
override func viewDidLoad() {
super.viewDidLoad()
self.myCollView.delegate = self
self.myCollView.dataSource = self
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
getData()
myCollView.reloadData()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return tasks.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "connectCell", for: indexPath) as! MyCollectionViewCell
let task = tasks[indexPath.row]
cell.labelTe?.text = task.name!
self.myCollView.backgroundColor = UIColor.clear
cell.layer.cornerRadius = 25
return cell
}
func getData() {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
do {
tasks = try context.fetch(Task.fetchRequest())
}
catch {
print("Ahhhhhhhh")
}
}

Answer 1

If I am guessing right, and upon clicking a cell on the first collection view, you want to segue to another collection view, where you will display display data according to the selected cell.
In order to achieve this, simply add collectionView(_ collectionView:, didSelectItemAt indexPath:) and prepare(for segue:, sender:) functions in your first view controller.
In the collectionView(_ collectionView:, didSelectItemAt indexPath:) function get the id of the task selected by determine which cell was selected, then pass this id to the second view controller in prepare(for segue:, sender:) function.
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as! MyCollectionViewCell
id = cell.labelTe?.text
}
or
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
id = tasks[indexPath.row].id
}
Then pass this value in your prepare(for segue:, sender:) function to the second viewController.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "YourIdentifier"{
let destinationViewController = segue.destination as! SecondViewController
destinationViewController.id = id
}
}
Make sure to add a var id in both your viewControllers. In the second viewController, use this id to fetch the data of the selected task that you want to display.
Hope this helps.
EDIT
Simply declare a new variable id of your particular type in both the viewControllers. In your first viewController :
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
var id = ""
and in the second viewController
class secondViewController: UIViewController {
var id = ""
Just make sure that both the variable are of same type.