RxSwift S3 Upload Sample

.env

AWS_IDENTITY_POOL_ID="xxxxxxx"

AppDelegate.swift

import UIKit
import CoreData
import AWSCognito

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        self.initEnv()
        let env = ProcessInfo.processInfo.environment
        let credentialsProvider = AWSCognitoCredentialsProvider(
            regionType:.APNortheast1,
            identityPoolId: env["AWS_IDENTITY_POOL_ID"]!
        )
        let configuration = AWSServiceConfiguration(region:.APNortheast1, credentialsProvider:credentialsProvider)

        AWSServiceManager.default().defaultServiceConfiguration = configuration
        RxImagePickerDelegateProxy.register { RxImagePickerDelegateProxy(imagePicker: $0) }

        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
        // Saves changes in the application's managed object context before the application terminates.
        self.saveContext()
    }

    // MARK: - Core Data stack

    lazy var persistentContainer: NSPersistentContainer = {
        /*
         The persistent container for the application. This implementation
         creates and returns a container, having loaded the store for the
         application to it. This property is optional since there are legitimate
         error conditions that could cause the creation of the store to fail.
        */
        let container = NSPersistentContainer(name: "appname")
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                 
                /*
                 Typical reasons for an error here include:
                 * The parent directory does not exist, cannot be created, or disallows writing.
                 * The persistent store is not accessible, due to permissions or data protection when the device is locked.
                 * The device is out of space.
                 * The store could not be migrated to the current model version.
                 Check the error message to determine what the actual problem was.
                 */
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        return container
    }()

    // MARK: - Core Data Saving support

    func saveContext () {
        let context = persistentContainer.viewContext
        if context.hasChanges {
            do {
                try context.save()
            } catch {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                let nserror = error as NSError
                fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
            }
        }
    }

    private func initEnv() {
        guard let path = Bundle.main.path(forResource: ".env", ofType: nil) else {
            fatalError("Not found: '/path/to/.env'.\nPlease create .env file reference from .env.sample")
        }
        let url = URL(fileURLWithPath: path)
        do {
            let data = try Data(contentsOf: url)
            let str = String(data: data, encoding: .utf8) ?? "Empty File"
            let clean = str.replacingOccurrences(of: "\"", with: "").replacingOccurrences(of: "'", with: "")
            let envVars = clean.components(separatedBy:"\n")
            for envVar in envVars {
                let keyVal = envVar.components(separatedBy:"=")
                if keyVal.count == 2 {
                    setenv(keyVal[0], keyVal[1], 1)
                }
            }
        } catch {
            fatalError(error.localizedDescription)
        }
    }
}

PreviewImage.swift

import UIKit

@IBDesignable
public final class PreviewImage: UIImageView {
    public override init(frame: CGRect) {
        super.init(frame: frame)
        configure()
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        configure()
    }
    
    public override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        configure()
    }
    
    private func configure() {
        backgroundColor = #colorLiteral(red: 0, green: 0.6730770469, blue: 1, alpha: 1)
        layer.shadowOpacity = 0.3
        layer.shadowOffset = CGSize(width: 0, height: 1)
        layer.shadowRadius = 4
        layer.shadowColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1).cgColor
    }
}

PrimaryActionButton.swift

import UIKit

@IBDesignable
public final class PrimaryActionButton: UIButton {
    public override init(frame: CGRect) {
        super.init(frame: frame)
        configure()
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        configure()
    }
    
    public override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        configure()
    }
    
    private func configure() {
        backgroundColor = #colorLiteral(red: 0, green: 0.6730770469, blue: 1, alpha: 1)
        layer.cornerRadius = 24
        titleLabel?.font = UIFont.boldSystemFont(ofSize: 19)
        setTitleColor(#colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0), for: .normal)
        
        layer.shadowOpacity = 0.3
        layer.shadowOffset = CGSize(width: 0, height: 1)
        layer.shadowRadius = 4
        layer.shadowColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1).cgColor
    }
}

RxImagePickerDelegateProxy.swift

import RxSwift
import RxCocoa
import UIKit

open class RxImagePickerDelegateProxy
: RxNavigationControllerDelegateProxy, UIImagePickerControllerDelegate {
    public init(imagePicker: UIImagePickerController) {
        super.init(navigationController: imagePicker)
    }
}

SelectPhotoViewModel.swift

import RxSwift
import RxCocoa
import UIKit
import Foundation

struct SelectPhotoViewModelInput {
    let targetController: ViewController
    let selectPhotoButton: Observable<Void>
    let previewImage: UIImageView
}

protocol SelectPhotoViewModelOutout {}

protocol SelectPhotoViewModelType {
    var outputs: SelectPhotoViewModelOutout? { get }
    func setup(input: SelectPhotoViewModelInput)
}

class SelectPhotoViewModel: SelectPhotoViewModelType {
    var outputs: SelectPhotoViewModelOutout?
    
    private let disposeBag = DisposeBag()
    
    init() {
        self.outputs = self
    }
    func setup(input: SelectPhotoViewModelInput) {
        input.selectPhotoButton
            .subscribe({ [unowned self] _ in
                UIImagePickerController.rx.createWithParent(input.targetController) { picker in
                    picker.sourceType = .photoLibrary
                    picker.allowsEditing = false
                }
                .flatMap {
                    $0.rx.didFinishPickingMediaWithInfo
                }
                .take(1)
                .map { info in
                    return info[UIImagePickerController.InfoKey.originalImage] as? UIImage
                }
                .bind(to: input.previewImage.rx.image)
                .disposed(by: self.disposeBag)
            })
            .disposed(by: self.disposeBag)
    }
}

extension SelectPhotoViewModel: SelectPhotoViewModelOutout {}

UIImagePickerController+Rx.swift

import RxSwift
import RxCocoa
import UIKit

extension Reactive where Base: UIImagePickerController {
    public var didFinishPickingMediaWithInfo: Observable<[UIImagePickerController.InfoKey: Any]> {
        return delegate
            .methodInvoked(#selector(UIImagePickerControllerDelegate.imagePickerController(_:didFinishPickingMediaWithInfo:)))
            .map({ (a) in
                return try castOrThrow(Dictionary<UIImagePickerController.InfoKey, Any>.self, a[1])
            })
    }
    
    public var didCancel: Observable<()> {
        return delegate
            .methodInvoked(#selector(UIImagePickerControllerDelegate.imagePickerControllerDidCancel(_:)))
            .map { _ in () }
    }
    
    public var task: Observable<[UIImagePickerController.InfoKey: Any]> {
        return Observable
            .of(
                didFinishPickingMediaWithInfo.map { Optional.some($0)! },
                didCancel.map { Optional.none! }
            )
            .merge()
            .take(1)
    }
}

fileprivate func castOrThrow<T>(_ resultType: T.Type, _ object: Any) throws -> T {
    guard let returnValue = object as? T else {
        throw RxCocoaError.castingError(object: object, targetType: resultType)
    }
    
    return returnValue
}

UIImagePickerController+RxCreate.swift

import UIKit
import RxSwift
import RxCocoa

func dismissViewController(_ viewController: UIViewController, animated: Bool) {
    if viewController.isBeingDismissed || viewController.isBeingPresented {
        DispatchQueue.main.async {
            dismissViewController(viewController, animated: animated)
        }
        
        return
    }
    
    if viewController.presentingViewController != nil {
        viewController.dismiss(animated: animated, completion: nil)
    }
}

extension Reactive where Base: UIImagePickerController {
    static func createWithParent(_ parent: UIViewController?, animated: Bool = true, configureImagePicker: @escaping (UIImagePickerController) throws -> Void = { x in }) -> Observable<UIImagePickerController> {
        return Observable.create { [weak parent] observer in
            let imagePicker = UIImagePickerController()
            let dismissDisposable = imagePicker.rx
                .didCancel
                .subscribe(onNext: { [weak imagePicker] _ in
                    guard let imagePicker = imagePicker else {
                        return
                    }
                    dismissViewController(imagePicker, animated: animated)
                })
            
            do {
                try configureImagePicker(imagePicker)
            }
            catch let error {
                observer.on(.error(error))
                return Disposables.create()
            }
            
            guard let parent = parent else {
                observer.on(.completed)
                return Disposables.create()
            }
            
            parent.present(imagePicker, animated: animated, completion: nil)
            observer.on(.next(imagePicker))
            
            return Disposables.create(dismissDisposable, Disposables.create {
                dismissViewController(imagePicker, animated: animated)
            })
        }
    }
}

UploadPhotoViewModel.swift

import RxSwift
import RxCocoa
import UIKit
import AWSS3
import Foundation

struct UploadPhotoViewModelInput {
    let targetController: ViewController
    let uploadPhotoButton: Observable<Void>
    let previewImage: UIImageView
}

protocol UploadPhotoViewModelOutout {}

protocol UploadPhotoViewModelType {
    var outputs: UploadPhotoViewModelOutout? { get }
    func setup(input: UploadPhotoViewModelInput)
}

class UploadPhotoViewModel: UploadPhotoViewModelType {
    var outputs: UploadPhotoViewModelOutout?
    
    private let disposeBag = DisposeBag()
    
    init() {
        self.outputs = self
    }

    func setup(input: UploadPhotoViewModelInput) {
        input.uploadPhotoButton
            .subscribe({ [unowned self] _ in
                let tmpPath:String =  NSTemporaryDirectory() + "image.png"
                let localFilePath:URL = self.savePNGImage(to: tmpPath, image: input.previewImage.image!) as URL
                let transfer: AWSS3TransferUtility = AWSS3TransferUtility.default()
                let expression = AWSS3TransferUtilityUploadExpression()
                expression.progressBlock = {(task, progress) in
                    DispatchQueue.main.async {
                        print("uploading...")
                    }
                }
                let completionHandler: AWSS3TransferUtilityUploadCompletionHandlerBlock?
                completionHandler = { (task, error) -> Void in
                    DispatchQueue.main.async {
                        if error != nil {
                            print("error")
                        } else {
                            print("success")
                        }
                    }
                }
                transfer.uploadFile(localFilePath, bucket: "save-bucket-name", key: "key/image.png", contentType: "image/png", expression: expression, completionHandler: completionHandler)
            })
            .disposed(by: self.disposeBag)
    }
    
    private func savePNGImage(to filePath: String, image: UIImage) -> NSURL {
        let imageData:NSData = image.pngData()! as NSData
        imageData.write(toFile: filePath, atomically: true)
        return NSURL(fileURLWithPath: filePath)
    }
}

extension UploadPhotoViewModel: UploadPhotoViewModelOutout {}

ViewController.swift

import RxSwift
import RxCocoa
import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var selectPhotoButton: PrimaryActionButton!
    @IBOutlet weak var uploadPhotoButton: PrimaryActionButton!
    @IBOutlet weak var previewImageView: UIImageView!

    private let disposeBag = DisposeBag()
    private var selectPhotoViewModel: SelectPhotoViewModel!
    private var uploadPhotoViewModel: UploadPhotoViewModel!

    override func viewDidLoad() {
        super.viewDidLoad()
        setupViewModel()
    }

    private func setupViewModel() {
        selectPhotoViewModel = SelectPhotoViewModel()
        selectPhotoViewModel.setup(input: SelectPhotoViewModelInput(
                targetController: self,
                selectPhotoButton: selectPhotoButton.rx.tap.asObservable(),
                previewImage: previewImageView
        ))
        uploadPhotoViewModel = UploadPhotoViewModel()
        uploadPhotoViewModel.setup(input: UploadPhotoViewModelInput(
            targetController: self,
            uploadPhotoButton: uploadPhotoButton.rx.tap.asObservable(),
            previewImage: previewImageView
        ))
    }
}