DelegateProxy example

UIPickerController+Rx.swift

// MARK:- UIImagePickerController.rx

import UIKit
import RxSwift
import RxCocoa

// picker.rx.didFinishPickingMediaWithInfo
// ~~~~~~ ~~
// Base   Reactive

extension Reactive where Base: UIImagePickerController {

    public var didFinishPickingMediaWithInfo: Observable<[String : Any]> {
        return RxImagePickerProxy.proxy(for: base)
            .didFinishPickingMediaWithInfoSubject
            .asObservable()
            .do(onCompleted: {
                self.base.dismiss(animated: true, completion: nil)
            })
    }

    public var didCancel: Observable<Void> {
        return RxImagePickerProxy.proxy(for: base)
            .didCancelSubject
            .asObservable()
            .do(onCompleted: {
                self.base.dismiss(animated: true, completion: nil)
            })
    }

}

public typealias ImagePickerDelegate = UIImagePickerControllerDelegate & UINavigationControllerDelegate

extension UIImagePickerController: HasDelegate {
    public typealias Delegate = ImagePickerDelegate
}

class RxImagePickerProxy: DelegateProxy<UIImagePickerController, ImagePickerDelegate>, DelegateProxyType, UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
    public init(imagePicker: UIImagePickerController) {
        super.init(parentObject: imagePicker, delegateProxy: RxImagePickerProxy.self)
    }

    //MARK:- DelegateProxyType

    public static func registerKnownImplementations() {
        self.register { RxImagePickerProxy(imagePicker: $0) }
    }

    static func currentDelegate(for object: UIImagePickerController) -> ImagePickerDelegate? {
        return object.delegate
    }

    static func setCurrentDelegate(_ delegate: ImagePickerDelegate?, to object: UIImagePickerController) {
        object.delegate = delegate
    }

    //MARK:- Proxy Subject

    internal lazy var didFinishPickingMediaWithInfoSubject = PublishSubject<[String : Any]>()
    internal lazy var didCancelSubject = PublishSubject<Void>()

    //MARK:- UIImagePickerControllerDelegate

    func imagePickerController(_ picker: UIImagePickerController,
                               didFinishPickingMediaWithInfo info: [String: Any]) {
        didFinishPickingMediaWithInfoSubject.onNext(info)
        didFinishPickingMediaWithInfoSubject.onCompleted()
        didCancelSubject.onCompleted()
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        didCancelSubject.onNext(())
        didCancelSubject.onCompleted()
        didFinishPickingMediaWithInfoSubject.onCompleted()
    }

    //MARK:- Completed

    deinit {
        self.didFinishPickingMediaWithInfoSubject.onCompleted()
        self.didCancelSubject.onCompleted()
    }

}

good