MyCollectionViewController #2

MyCollectionViewController2.swift

import UIKit

struct CollectionItemModel {
    let title: String?
    let image: UIImage?
}

struct CellController {
    var model: CollectionItemModel
    func getCell(collectionView: UICollectionView, indexPath: IndexPath) -> UICollectionViewCell {
        if let image = model.image {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "image", for: indexPath)
            cell.largeContentImage = image
            return cell
        } else if let title = model.title {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "text", for: indexPath)
            cell.largeContentTitle = title
            return cell
        }
        return UICollectionViewCell()
    }

}

/// First set `model` and then present on screen.
final class MyCollectionViewController: UICollectionViewController {
    var cellControllers: [CellController]?
    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cellController = cellControllers?[indexPath.row]
        let cell = cellController?.getCell(collectionView: collectionView, indexPath: indexPath) ?? UICollectionViewCell()
        return cell
    }
}

func createMyCollectionViewController() -> MyCollectionViewController {
    let collectionViewController = MyCollectionViewController()
    let cellControllers = [
        CellController(model: .init(title: nil, image: UIImage(named: "what"))),
        CellController(model: .init(title: "Text", image: nil))
    ]
    collectionViewController.cellControllers = cellControllers
    return collectionViewController
}