collectionview-wrapper.swift

import UIKit

class CollectionViewCellWrapper<View: NibLoadable & UIView> {
  
  static func register(in collectionView: UICollectionView) {
    collectionView.register(WrappedCollectionViewCell<View>.self, forCellWithReuseIdentifier: View.name)
  }
  
  static func forceGet(from collectionView: UICollectionView, in indexPath: IndexPath) -> WrappedCollectionViewCell<View> {
    let cell = collectionView.cellForItem(at: indexPath) as! WrappedCollectionViewCell<View>

    return cell
  }
  
  static func get(from collectionView: UICollectionView, in indexPath: IndexPath) -> WrappedCollectionViewCell<View> {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: View.name, for: indexPath) as! WrappedCollectionViewCell<View>
    return cell
  }
}

@dynamicMemberLookup
class WrappedCollectionViewCell<View: NibLoadable & UIView>: UICollectionViewCell {
  private(set) var view: View = View.loadFromNib()
  
  subscript<T>(dynamicMember keyPath: KeyPath<View, T>) -> T {
    return self.view[keyPath: keyPath]
  }
  
  override func didMoveToSuperview() {
    super.didMoveToSuperview()
    let cell = self
    cell.addSubview(view)
    let constraints = ConstraintConstructor(subview: view).superViewCovered().constraints
    cell.addConstraints(constraints)
  }
}