Table/Collection Views - Generic Cell Registration & Dequeuing

NibNameableView.swift

import UIKit

public protocol NibNameableView: class {
    static var nibName: String { get }
}

extension NibNameableView where Self: UIView {
    public static var nibName: String {
        return String(describing: self)
    }
}

ReusableView.swift

import UIKit

public protocol ReusableView: class {
    static var reusableIdentifier: String { get }
}

extension ReusableView where Self: UIView {
    public static var reusableIdentifier: String {
        return String(describing: self)
    }
}

UICollectionView.swift

import UIKit

extension UICollectionView {
    public enum SupplementaryViewKind {
        case header
        case footer

        public var rawValue: String {
            switch self {
            case .header:
                return UICollectionView.elementKindSectionHeader
            case .footer:
                return UICollectionView.elementKindSectionFooter
            }
        }
    }

    public func register<Cell: UICollectionViewCell>(cell: Cell.Type, inBundle bundle: Bundle) where Cell: ReusableView, Cell: NibNameableView {
        let nib = UINib(nibName: Cell.nibName, bundle: bundle)
        register(nib, forCellWithReuseIdentifier: Cell.reusableIdentifier)
    }

    public func register<View: UICollectionReusableView>(view: View.Type, inBundle bundle: Bundle, asSupplementaryViewKind kind: SupplementaryViewKind) where View: ReusableView, View: NibNameableView {
        let nib = UINib(nibName: View.nibName, bundle: bundle)
        register(nib, forSupplementaryViewOfKind: kind.rawValue, withReuseIdentifier: View.reusableIdentifier)
    }
}

extension UICollectionView {
    public func dequeueReusableCell<Cell: UICollectionViewCell>(forIndexPath indexPath: IndexPath) -> Cell where Cell: ReusableView {
        guard let cell = dequeueReusableCell(withReuseIdentifier: Cell.reusableIdentifier, for: indexPath) as? Cell else {
            fatalError("Could not dequeue cell with identifier: \(Cell.reusableIdentifier)")
        }
        return cell
    }

    public func dequeueReusableSupplementaryView<View: UICollectionReusableView>(ofKind kind: SupplementaryViewKind, forIndexPath indexPath: IndexPath) -> View where View: ReusableView {
        guard let view = dequeueReusableSupplementaryView(ofKind: kind.rawValue, withReuseIdentifier: View.reusableIdentifier, for: indexPath) as? View else {
            fatalError("Could not dequeue view with identifier: \(View.reusableIdentifier)")
        }
        return view
    }
}

UITableView.swift

import UIKit

extension UITableView {
    public func register<Cell: UITableViewCell>(cell: Cell.Type, inBundle bundle: Bundle) where Cell: ReusableView, Cell: NibNameableView {
        let nib = UINib(nibName: Cell.nibName, bundle: bundle)
        register(nib, forCellReuseIdentifier: Cell.reusableIdentifier)
    }

    public func register<View: UITableViewHeaderFooterView>(headerFooterView: View.Type, inBundle bundle: Bundle) where View: ReusableView, View: NibNameableView {
        let nib = UINib(nibName: View.nibName, bundle: bundle)
        register(nib, forHeaderFooterViewReuseIdentifier: View.reusableIdentifier)
    }
}

extension UITableView {
    public func dequeueReusableCell<Cell: UITableViewCell>(forIndexPath indexPath: IndexPath) -> Cell where Cell: ReusableView {
        guard let cell = dequeueReusableCell(withIdentifier: Cell.reusableIdentifier, for: indexPath) as? Cell else {
            fatalError("Could not dequeue cell with identifier: \(Cell.reusableIdentifier)")
        }
        return cell
    }

    public func dequeueReusableHeaderFooterView<View: UITableViewHeaderFooterView>() -> View where View: ReusableView {
        guard let view = dequeueReusableHeaderFooterView(withIdentifier: View.reusableIdentifier) as? View else {
            fatalError("Could not dequeue header/footer view with identifier: \(View.reusableIdentifier)")
        }
        return view
    }
}