Swift: Generic Reusable collection view trying to adding multiple cell support - swift

Question

I followed several cars to create a collectionViewDataSource, and I am extremely happy with the result:
let dataSource = CollectionViewDataSourceProvider(items: domains, cell: EditDomainsCollectionViewCell.self) { indexPath, item, cell in
cell.setup(with: item)
}.registerCell(for: domainsCollectionView)
self.datasource = dataSource
domainsCollectionView.dataSource = datasource
domainsCollectionView.delegate = datasource
Here my dataSourceProvider class:
class CollectionViewDataSourceProvider<Item, Cell: UICollectionViewCell & NibLoadableView>: NSObject, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
typealias CellConfigurator = (_ indexPath: IndexPath, _ item: Item, _ cell: Cell) -> ()
typealias SizeConfigurator = (_ indexPath: IndexPath, _ item: Item) -> CGSize
typealias WidthConfigurator = (_ section: Int) -> CGFloat
typealias InsetConfigurator = (_ section: Int) -> UIEdgeInsets
typealias SelectConfigurator = (_ indexPath: IndexPath, _ item: Item) -> ()
private let items: [Item]
private let cell: Cell.Type
private let cellConfigurator: CellConfigurator
private var sizeConfigurator: SizeConfigurator?
private var minimumLineSpacingForSectionAtConfigurator: WidthConfigurator?
private var minimumInteritemSpacingForSectionAt: WidthConfigurator?
private var insetForSectionAt: InsetConfigurator?
private var didSelectItemAt: SelectConfigurator?
init(items: [Item], cell: Cell.Type, cellConfigurator: #escaping CellConfigurator) {
self.items = items
self.cell = cell
self.cellConfigurator = cellConfigurator
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items.count
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let model = items[indexPath.row]
let cell = loadNIB()
return sizeConfigurator?(indexPath, model) ?? cell.frame.size
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return minimumInteritemSpacingForSectionAt?(section) ?? (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)?.minimumLineSpacing ?? 1
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return insetForSectionAt?(section) ?? (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)?.sectionInset ?? UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
didSelectItemAt?(indexPath, items[indexPath.row])
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return minimumLineSpacingForSectionAtConfigurator?(section) ?? (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)?.minimumLineSpacing ?? 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let model = items[indexPath.row]
let cell: Cell = collectionView.dequeueReusableCell(forIndexPath: indexPath)
cellConfigurator(indexPath, model, cell)
return cell
}
private func loadNIB() -> Cell {
return Bundle(for: Cell.self as AnyClass).loadNibNamed(String(describing: Cell.self), owner: nil, options: nil)![0] as! Cell
}
}
extension CollectionViewDataSourceProvider {
func registerCell(for collectionView: UICollectionView, flowLayout: UICollectionViewFlowLayout? = nil) -> CollectionViewDataSourceProvider {
collectionView.register(cell)
if let flowLayout = flowLayout {
collectionView.setCollectionViewLayout(flowLayout, animated: true)
}
return self
}
func heightForRow(config: #escaping SizeConfigurator) -> CollectionViewDataSourceProvider {
sizeConfigurator = config
return self
}
func minimumLineSpacingForSectionAt(config: #escaping WidthConfigurator) -> CollectionViewDataSourceProvider {
minimumLineSpacingForSectionAtConfigurator = config
return self
}
func minimumInteritemSpacingForSectionAt(config: #escaping WidthConfigurator) -> CollectionViewDataSourceProvider {
minimumInteritemSpacingForSectionAt = config
return self
}
func insetForSectionAt(config: #escaping InsetConfigurator) -> CollectionViewDataSourceProvider {
insetForSectionAt = config
return self
}
func didSelectedAt(config: #escaping SelectConfigurator) -> CollectionViewDataSourceProvider {
didSelectItemAt = config
return self
}
}
After all, I am trying to implement the possibility of using several different cell by protocol but I cannot adapt it with my provider class.
Here is the pattern I want to make to create multiple cell types quite simply:
enum CellType {
case typeOne, typeTwo
var identifier: String {
switch self {
case .typeOne:
return NSStringFromClass(CellOne.self)
case .typeTwo:
return NSStringFromClass(CellTwo.self)
}
}
}
protocol CustomElement {
var type: CellType { get }
}
class MyFirstObject: CustomElement {
var type: CellType { .typeOne}
}
class MySecondObject: CustomElement {
var type: CellType { .typeTwo}
}
protocol CellElement where Self: UICollectionViewCell & NibLoadableView {
func configure(with object: CustomElement)
}
class CellOne: UICollectionViewCell, CellElement, NibLoadableView {
func configure(with object: CustomElement) {
guard let object = object as? MySecondObject else { return }
//
}
}
class CellTwo: UICollectionViewCell, CellElement, NibLoadableView {
func configure(with object: CustomElement) {
guard let object = object as? MyFirstObject else { return }
//
}
}
The NibLoadableView protocol comes from this gist, to save cells easily https://gist.github.com/gonzalezreal/92507b53d2b1e267d49a
I want my collectionViewDataSourceProvider to be able to receive in the init an array of UICollectionView cell, and if there is more than one cell then implement the protocol logic for multiple cell. But I can't do it.
For example, I am trying to set the protocol as a generic parameter in my datasource, but it tells me that the protocol does not inherit from IUCollectionView.
I have no direction how to do this thank you for your help