Mobile Bialystok #5 Dependency Injection iOS @Michał Karpowicz

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Dependency Injection + iOSMichał Karpowicz


00WSTĘP


1.Dependency Injection2.TDD3.DYI4.Typhoon


Projekt

• Dwa View Controllery – DashboardViewController i CustomersViewController• CustomersDataSource• CustomerService• SessionManager


01Dependency Injection


Inversion of Control


Cele

•Podział na moduły•Rozszerzalność


Dependency Injection

class CustomersDataSource: NSObject { let service: CustomerService override init() { service = CustomerService(manager: SessionManager(baseUrl: "https://api.customer.com", configuration: NSURLSessionConfiguration(), timeout: 30)) } }




Rodzaje DI

•Extract and override•Method injection•Property injection•Constructor injection


DEPENDENCY INJECTION?

import UIKitimport Foundation

class UserCredentials { private let authorizationTokenKey = "AuthorizationTokenKey" func getAuthorizationToken() -> String { let value = NSUserDefaults.standardUserDefaults().stringForKey(authorizationTokenKey) guard let retVal = value else { return "" } return retVal }}


EXTRACT AND OVERRIDE

private let authorizationTokenKey = "AuthorizationTokenKey" func getAuthorizationToken() -> String { let value = userDefaults().stringForKey(authorizationTokenKey) guard let retVal = value else { return "" } return retVal } func userDefaults() -> NSUserDefaults { return NSUserDefaults.standardUserDefaults() }


METHOD INJECTION

private let authorizationTokenKey = "AuthorizationTokenKey" func getAuthorizationToken(userDefaults userDefaults: NSUserDefaults) -> String { let value = userDefaults.stringForKey(authorizationTokenKey) guard let retVal = value else { return "" } return retVal }


PROPERTY INJECTION

class UserCredentials { var userDefaults: NSUserDefaults! private let authorizationTokenKey = "AuthorizationTokenKey" func getAuthorizationToken() -> String { let value = userDefaults.stringForKey(authorizationTokenKey) guard let retVal = value else { return "" } return retVal }}

let credentials = UserCredentials()credentials.userDefaults = NSUserDefaults.standardUserDefaults()


CONSTRUCTOR INJECTION

private let userDefaults: NSUserDefaults private let authorizationTokenKey = "AuthorizationTokenKey" init(userDefaults: NSUserDefaults) { self.userDefaults = userDefaults } func getAuthorizationToken() -> String { let value = userDefaults.stringForKey(authorizationTokenKey) guard let retVal = value else { return "" } return retVal }

let credentials = UserCredentials(NSUserDefaults.standardUserDefaults())



class CustomersDataSource: NSObject { let service: CustomerService override init() { service = CustomerService(manager: SessionManager(baseUrl: "https://api.customer.com", configuration: NSURLSessionConfiguration(), timeout: 30)) } }



let service: CustomerService init(customerService: CustomerService) { service = customerService }



• Niezmienność obiektów• Klasy łatwe do testowania


02TDD


TDD

TDD + Dependency Injection = <3


TDD

Networking Tests


TDD

Response mock

class MockGETSessionManager: NSObject, SessionManagerProtocol { var success: ((AnyObject) -> ())! func GET(url: String, parameters: AnyObject?, success: (AnyObject) -> (), failure: () -> ()) { self.success = success } }

protocol SessionManagerProtocol { func GET(url: String, parameters: AnyObject?, success: (AnyObject) -> (), failure: () -> ())}


TDD

Testowanie mockafunc testMockGET() { let mockSessionManager = MockGETSessionManager() let customerService = CustomerService(sessionManager: mockSessionManager) let customerDataSource = CustomersDataSource(customerService: customerService) customerDataSource.fetchData() mockSessionManager.success(NSData()) XCTAssertNotNil(customerDataSource.customers) }


TDD

Frameworki• OCMockito (Objective-C) - https://github.com/jonreid/OCMockito• Mockingjay (Swift) - https://github.com/kylef/Mockingjay

https://github.com/jonreid/OCMockito

https://github.com/kylef/Mockingjay


03DYI


DIY


DIY

class Injector: NSObject { func dashboardViewController() -> DashboardViewController { let viewController = DashboardViewController() viewController.injector = self return viewController }}


DIY

class AppDelegate: UIResponder, UIApplicationDelegate {

/…/let injector = Injector()

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

window?.rootViewController = injector.dashboardViewController() return true }/.../}


DIY

func sessionManager() -> SessionManager { let sessionManager = SessionManager(baseUrl: "https://api.customer.com", configuration: NSURLSessionConfiguration(), timeout: 30) return sessionManager} func customerService() -> CustomerService { let customerService = CustomerService(sessionManager: sessionManager()) return customerService}func customerDataSource() -> CustomersDataSource { let dataSource = CustomersDataSource(customerService: customerService()) return dataSource }func customersViewController() -> CustomersViewController { let viewController = CustomersViewController() viewController.injector = self viewController.dataSource = customerDataSource() return viewController}


DIY

class DashboardViewController: UIViewController {

/.../

func showCustomersView() { let viewController = injector?.customersViewController() navigationController?.pushViewController(viewController!, animated: true) }}


04TYPHOON


Typhoon?

http://typhoonframework.org/

• Nie inwazyjny• Wsparcie constructor i property injection• Wstrzykiwanie view controllerów• Integracja ze storyboardami• Minimalne obciążenie CPU• Battle-tested• Aktywnie rozwijany• “Swift”!


Typhoon - Podstawy

1.Assembly – TyphoonAssembly2.Definition – TyphoonDefinition


Typhoon - Setup

1.Instalacja2.Stworzenie ApplicationAssembly – subclass TyphoonAssembly3.Dodanie listy TyphoonInitialAssembies do Info.plis

That’s it!


Typhoon - Instalacja

source 'https://github.com/CocoaPods/Specs.git'

platform :ios, '8.0'

use_frameworks!

target 'DI-Typhoon' do pod 'Typhoon'End

Podfile:

pod installTerminal:


Typhoon – ApplicationAssembly

import Typhoon

class ApplicationAssembly: TyphoonAssembly { dynamic func appDelegate() -> AnyObject { return TyphoonDefinition.withClass(AppDelegate.self) { definition in } }}


Typhoon

Real life scenario


Typhoon – Projekt startowy

Lista TyphoonAssemblies:• ApplicationAssembly• ViewControllerAssembly• DataSourceAssembly• CoreServicesAssembly


ApplicationAssembly

class ApplicationAssembly: TyphoonAssembly { var viewControllerAssembly: ViewControllerAssembly! dynamic func appDelegate() -> AnyObject { return TyphoonDefinition.withClass(AppDelegate.self) { definition in definition.injectProperty("viewControllerAssembly", with: self.viewControllerAssembly) } }}


ViewControllerAssembly

class ViewControllerAssembly: TyphoonAssembly { var dataSourceAssembly: DataSourceAssembly! dynamic func customersViewController() -> AnyObject { return TyphoonDefinition.withClass(CustomersViewController.self) { definition in definition.useInitializer("init") { initializer in } definition.injectProperty("dataSource", with: self.dataSourceAssembly.customerDataSource()) definition.injectProperty("viewControllerAssembly", with: self) } } /.../}


DataSourceAssembly

class DataSourceAssembly: TyphoonAssembly { var coreServicesAssembly: CoreServicesAssembly! dynamic func customerDataSource() -> AnyObject { return TyphoonDefinition.withClass(CustomersDataSource.self) { definition in definition.useInitializer("initWithCustomerService:") { initializer in initializer.injectParameterWith(self.coreServicesAssembly.customerService()) } } }}


CoreServicesAssembly

dynamic func sessionManager() -> AnyObject { return TyphoonDefinition.withClass(SessionManager.self) { definition in definition.useInitializer("initWithBaseUrl:configuration:timeout:") { initializer in initializer.injectParameterWith("https://api.customer.com") initializer.injectParameterWith(NSURLSessionConfiguration()) initializer.injectParameterWith(30) } } }dynamic func customerService() -> AnyObject { return TyphoonDefinition.withClass(CustomerService.self) { definition in definition.useInitializer("initWithSessionManager:") { initializer in initializer.injectParameterWith(self.sessionManager()) } } }


AppDelegate

class AppDelegate: UIResponder, UIApplicationDelegate {

/…/var viewControllerAssembly: ViewControllerAssembly!

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

window?.rootViewController = viewControllerAssembly.dashboardViewController() as! DashboardViewController return true }/.../}


Typhoon

Dlaczego “Swift”?


Typhoon


PYTANIA?


PYTANIA I CHABORY


DZIĘKUJĘ ZA UWAGĘ

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Technology

Mobile Bialystok #5 Dependency Injection iOS @Michał Karpowicz