iOS Clean Architecture

A talk about commons problems in iOS app, and solution based on clean Architecture.

Transcript

1. Mr proper ahora se llama don limpio! Clean Architecture Davide Mendolia
3. Davide Mendolia @davideme Full Stack Dev Swift Lover
4. Karumi is the Rock Solid Code software development studio. We embark on every project with a commitment to create something elegant, enduring and effective. That is our heartbeat. Our approach is uniquely simple and honest. We are a dedicated software studio delivering outstanding work.
5. Evolution iOS App Architecture
6. We build apps that display data from the network!
7. [
 {
 "id": 1,
 "name": "Yoda",
 "mood": "Sleepy"
 },
 {
 "id": 2,
 "name": "Audrey",
 "mood": "Crazy"
 }
 ] Data: JSON + Images Painting: UIKit
8. Common Problems
9. Architecture Evolution God ViewController
10. Similar code everywhere
11. Code difficult to follow
12. Start Searching for a solution
13. Needs • Separation of concerns • Reuse components • Testable
14. Model-View-Presenter ViewController Presenter Model
15. Clean Architecture
16. Layers Business Model UI
17. Layers USE CASE FRAMEWORKS
18. Layers USE CASE INTERFACE ADAPTERS FRAMEWORKS
19. USE CASE INTERFACE ADAPTERS FRAMEWORKS
20. The Dependency Rule USE CASE INTERFACE ADAPTERS FRAMEWORKS
21. VIPER
22. Boundaries + Immutability View Protocol ViewController Presenter Model
23. Model Still Complex
24. Repositories Abstraction Over Network Access and Caching Datasources • API • Memory • Disk
25. API Datasource APIClient APIParser + Data Transfer Object HTTP Client
26. Disk Datasource NSCoding class Book: NSObject, NSCoding { var title: String var author: String // Memberwise initializer init(title: String, author: String) { self.title = title self.author = author } // MARK: NSCoding required convenience init?(coder decoder: NSCoder) { guard let title = decoder.decodeObjectForKey("title") as? String, let author = decoder.decodeObjectForKey("author") as? String else { return nil } self.init( title: title, author: author ) } func encodeWithCoder(coder: NSCoder) { coder.encodeObject(self.title, forKey: "title") coder.encodeObject(self.author, forKey: "author") } }
27. Memory Datasource public class MemoryDataSource<T:Cacheable> { var items: OrderedDictionary<K, CacheItem<T>>? ... } public protocol Cacheable : NSCoding { func getKey() -> String } public protocol Cacheable : NSCoding { typealias K: Hashable func getKey() -> K }
28. Repository class Repository { let networkDataSource: DataSourceApi let readableDatasources: [BaseDataSource<DTO, String>] init(networkDataSource: DataSourceApi, memoryDataSource: MemoryDataSource<DTO, String>, diskDataSource: DiskDataSource<DTO, String>) { ... } }
29. Repository func getAll( forceRefresh excludeCachedDatasource: Bool = false, result: (Result<[Reclamation], NSError>) -> Void ) { ... } func getPage( offset: Int, limit: Int, forceRefresh excludeCachedDatasource: Bool = false, result: (Result<CollectionContainer<Reclamation>, NSError>) -> Void ) { ... } func get( key: String, result: (Result<Reclamation, NSError>) -> Void) { ... }
30. Repository func create(...) { networkDataSource.create(…). onComplete(Queue.main.context) { result in callback(result) } }
31. Repository v2 protocol ReadableDataSource { typealias T: Cacheable typealias K: Hashable func get(key: K) -> Future<T, NSError> func get(key: K) -> T? func getPage(offset offset: Int, limit: Int) -> Future<CollectionContainer<T>, NSError> func getPage(offset offset: Int, limit: Int) -> CollectionContainer<T>? func getAll() -> Future<[T], NSError> func getAll() -> [T]? func populate(items: [T]) func populate(collectionContainer: CollectionContainer<T>) func populate(collectionContainer: FullCollectionContainer<T>) }
32. Repository v2 class ReadableBaseRepository<T: Cacheable, K: Hashable where T.K == K> { let readableDatasources: [BaseDataSource<T, K>] init(networkDataSource: BaseDataSource<T, K>, memoryDataSource: MemoryDataSource<T, K>, diskDataSource: DiskDataSource<T, K>) { self.readableDatasources = [memoryDataSource, diskDataSource, networkDataSource] } }
33. Repository v2 func get( key: K, callback: (Result<T, NSError>) -> Void) { getVia(key, datasources: readableDatasources, excludeCachedDatasource: false) { repositoryResult in dispatch_async(dispatch_get_main_queue()) { callback(repositoryResult) } } }
34. Alamofire
35. API Client Authentication + Alamofire
36. API Client Authentication + Alamofire + Authentication Alamofire
37. API Client Interceptor + HTTP Client
38. Repository v2 class NSLogInterceptor: RequestInterceptor, ResponseInterceptor { public init() {} public func intercept(request: HTTPRequest) -> HTTPRequest { NSLog("-> \(request)") return request } public func intercept(response: HTTPResponse, completion: (Result<HTTPResponse, BothamAPIClientError>) -> Void) { NSLog("<- \(response)") completion(Result.Success(response)) } }
39. Repository v2 let apiClient = APIClient(baseEndpoint: "https://api.github.com/repos/ Karumi/") apiClient.requestInterceptors.append(NSLogInterceptor()) apiClient.responseInterceptors.append(NSLogInterceptor())
40. ViewModel public class MenuEntry: NSObject, Cacheable { public let name: String public let url: String public let image: String } protocol MenuEntryViewModel { var identifier: String { get } var name: String { get } var contentURL: NSURL? { get } var imageURL: NSURL? { get } } extension MenuEntry : MenuEntryViewModel { var contentURL: NSURL? { return NSURL(string: self.url) } var imageURL: NSURL? { return NSURL(string: self.image) } }
41. Use Case Presenter Use Case Repository
42. Use Case • Contains Business Logic • No code specific to a Framework • V1 - Group method in Use Case Class by Domain • How to abstract Async call ?
43. Use Case V2 • Use Command Pattern • One public method per class • Allow Reuse of Generic code by Presenter and UI • Loading • Error/Retry • Autoloading
44. Presenter + Command Use Case class GetMenuEntries: UseCase { let repository: MenuRepository init(categoryRepository repository: MenuRepository) { self.repository = repository } func execute(forceRefresh: Bool, callback: (Result<[MenuEntryViewModel], NSError>) -> Void) { self.repository.getAll(forceRefresh: forceRefresh) { repositoryResult in callback( repositoryResult.map { $0.map { $0 as MenuEntryViewModel } } ) } } }
45. Presenter + Command Use Case func loadItems(ui: StoreHomeUI) { UseCaseExecutor(ui: ui, showLoader: true) .execute(useCase, forceRefresh: false) { (result: Result<[MenuEntryViewModel], NSError>) in if let menuEntries = result.value where result.succeeded { ui.showMenuEntries(menuEntries) } } }
46. Flow ViewController Presenter Use Case Repository (API, Memory, Disk)DataSource
47. Missing Pieces
48. Dependencies Injection •Service Locator •Swinject •Typhoon
49. Dependency Injection func provideSuperHeroDetailViewController(superHeroName: String) -> UIViewController { let viewController: SuperHeroDetailViewController = storyBoard.instantiateViewController(“SuperHeroDetailViewController") viewController.presenter = provideSuperHeroDetailPresenter(viewController, erHeroName: superHeroName) return viewController }
50. Routing • Segues • TabBarViewController • NavigationViewController • Push • Search • Solution • Navigator • Wireframe
51. Async •Rx •PromiseKit •BrightFutures •Callback + GDC •NSOperations
52. Future
53. Botham • BothamUI (released) • BothamUseCase(Planned) • BothamRepository (In dev) • BothamNetworking (released) https:/ /github.com/Karumi https:/ /cocoapods.org/?q=botham
54. Questions ? BTW: We love stars, give us some on github, if you want :)
55. Mitsumori - Coupon https:/ /itunes.apple.com/es/app/mitsumori/id1066363442?mt=8