Easy dequeuing using reusable views

ReusableView+Additionals.swift

import UIKit
import MapKit

// MARK: - MKAnnotationView Extensions

extension MKAnnotationView: ReusableView {}

extension MKMapView {

    @warn_unused_result
    func dequeueReusableAnnotationViewWithAnnotation<T: MKAnnotationView where T: ReusableView>(annotation: MKAnnotation) -> T {
        if let annotationView = dequeueReusableAnnotationViewWithIdentifier(T.defaultReuseIdentifier) as? T {
            annotationView.annotation = annotation
            return annotationView
        } else {
            return T(annotation: annotation, reuseIdentifier: T.defaultReuseIdentifier)
        }
    }

}

// MARK: - UITableView Extensions

extension UITableViewCell: ReusableView {}

extension UITableViewHeaderFooterView: ReusableView {}

extension UITableView {

    func registerCell<T: UITableViewCell where T: ReusableView>(_: T.Type) {
        registerClass(T.self, forCellReuseIdentifier: T.defaultReuseIdentifier)
    }
   
    func registerHeaderFooterView<T: UITableViewHeaderFooterView where T: ReusableView>(_: T.Type) {
        registerClass(T.self, forHeaderFooterViewReuseIdentifier: T.defaultReuseIdentifier)
    }
    
    @warn_unused_result
    func dequeueReusableCell<T: UITableViewCell where T: ReusableView>(forIndexPath indexPath: NSIndexPath) -> T {
        guard let cell = dequeueReusableCellWithIdentifier(T.defaultReuseIdentifier, forIndexPath: indexPath) as? T else {
            fatalError("Could not dequeue cell with identifier: '\(T.defaultReuseIdentifier)'")
        }
        return cell
    }
    
    @warn_unused_result
    func dequeueReusableHeaderFooter<T: UITableViewHeaderFooterView where T: ReusableView>() -> T {
        guard let view = dequeueReusableHeaderFooterViewWithIdentifier(T.defaultReuseIdentifier) as? T else {
            fatalError("Could not dequeue UITableViewHeaderFooterView with identifier: '\(T.defaultReuseIdentifier)'")
        }
        return view
    }
    
}

// MARK: - UICollectionView Extensions

extension UICollectionViewCell: ReusableView {}

extension UICollectionView {

    func registerCell<T: UICollectionViewCell where T: ReusableView>(_: T.Type) {
        registerClass(T.self, forCellWithReuseIdentifier: T.defaultReuseIdentifier)
    }

    func registerSupplementaryFooterView<T: UICollectionViewCell where T: ReusableView>(_: T.Type) {
        registerClass(T.self, forSupplementaryViewOfKind: UICollectionElementKindSectionFooter, withReuseIdentifier: T.defaultReuseIdentifier)
    }

    func registerSupplementaryHeaderView<T: UICollectionViewCell where T: ReusableView>(_: T.Type) {
        registerClass(T.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: T.defaultReuseIdentifier)
    }
    
    @warn_unused_result
    func dequeueReusableCell<T: UICollectionViewCell where T: ReusableView>(forIndexPath indexPath: NSIndexPath) -> T {
        guard let cell = dequeueReusableCellWithReuseIdentifier(T.defaultReuseIdentifier, forIndexPath: indexPath) as? T else {
            fatalError("Could not dequeue cell with identifier: '\(T.defaultReuseIdentifier)'")
        }
        return cell
    }
    
    @warn_unused_result
    func dequeueReusableSupplementaryViewOfKind<T: UICollectionViewCell where T: ReusableView>(kind: String, forIndexPath indexPath: NSIndexPath) -> T {
        guard let view = dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: T.defaultReuseIdentifier, forIndexPath: indexPath) as? T else {
            fatalError("Could not dequeue supplementary view of kind '\(kind)' with identifier: '\(T.defaultReuseIdentifier)'")
        }
        return view
    }
    
}

ReusableViews.swift

import UIKit

protocol ReusableView: class {
    static var defaultReuseIdentifier: String { get }
}

extension ReusableView where Self: UIView {
    /**
     Default reuse identifier which is usefull for registering and dequeing a `ReusableView`
     from a view which supports dequeing of subviews like `UITableView` and `UICollectionView`.
     - Return a default reuse identifier based on the name of the class.
     */
    static var defaultReuseIdentifier: String {
        return String(self)
    }
}