From 05864c2584b48b4755e66042b34a6f2b53b89556 Mon Sep 17 00:00:00 2001 From: Patrice Chalin Date: Fri, 3 Jun 2016 11:16:46 -0700 Subject: [PATCH] docs(dependency-injection): revised Dart and TS code and prose (#1573) docs(dependency-injection): revise Dart and TS code and prose --- .../dart/example-config.json | 0 .../dart/lib/app_component.dart | 25 +- .../dart/lib/app_component_1.dart | 10 - .../dart/lib/app_component_2.dart | 13 +- .../dart/lib/app_config.dart | 32 +- .../dart/lib/car/car.dart | 17 +- .../dart/lib/car/car_creations.dart | 57 +- .../dart/lib/car/car_factory.dart | 7 +- .../dart/lib/car/car_injector.dart | 35 +- .../dart/lib/car/car_no_di.dart | 3 +- .../dart/lib/heroes/hero.dart | 8 +- .../dart/lib/heroes/hero_list_component.dart | 7 +- .../lib/heroes/hero_list_component_2.dart | 12 +- .../dart/lib/heroes/hero_service.dart | 2 +- .../dart/lib/heroes/hero_service_1.dart | 3 + .../dart/lib/heroes/hero_service_2.dart | 1 - .../lib/heroes/hero_service_provider.dart | 3 +- .../dart/lib/heroes/heroes_component_1.dart | 20 +- .../dart/lib/heroes/mock_heroes.dart | 57 +- .../dart/lib/injector_component.dart | 37 +- .../dart/lib/logger_service.dart | 5 +- .../dart/lib/providers_component.dart | 284 +++---- .../dart/lib/test_component.dart | 65 ++ .../dart/lib/user_service.dart | 35 +- .../dart/test/hero_list_component_test.dart | 9 +- .../dependency-injection/dart/web/main.dart | 3 +- .../dependency-injection/dart/web/main_1.dart | 27 +- .../dependency-injection/e2e-spec.ts | 24 +- .../ts/app/app.component.1.ts | 11 - .../ts/app/app.component.2.ts | 17 +- .../ts/app/app.component.ts | 16 +- .../dependency-injection/ts/app/app.config.ts | 6 +- .../ts/app/car/car-injector.ts | 40 +- .../dependency-injection/ts/app/car/car.ts | 9 +- .../ts/app/heroes/hero-list.component.1.ts | 2 +- .../ts/app/heroes/hero-list.component.2.ts | 8 + .../ts/app/heroes/hero-list.component.ts | 3 +- .../ts/app/heroes/hero.service.1.ts | 7 +- .../ts/app/heroes/heroes.component.1.ts | 19 +- .../ts/app/heroes/mock-heroes.ts | 20 +- .../ts/app/injector.component.ts | 28 +- .../ts/app/logger.service.ts | 3 +- .../dependency-injection/ts/app/main.1.ts | 16 +- .../dependency-injection/ts/app/main.ts | 1 - .../ts/app/providers.component.ts | 152 ++-- .../ts/app/test.component.ts | 4 +- .../ts/app/user.service.ts | 29 +- .../latest/guide/dependency-injection.jade | 373 +++------ .../ts/latest/guide/dependency-injection.jade | 775 +++++++++--------- 49 files changed, 1041 insertions(+), 1299 deletions(-) create mode 100644 public/docs/_examples/dependency-injection/dart/example-config.json create mode 100644 public/docs/_examples/dependency-injection/dart/lib/test_component.dart diff --git a/public/docs/_examples/dependency-injection/dart/example-config.json b/public/docs/_examples/dependency-injection/dart/example-config.json new file mode 100644 index 0000000000..e69de29bb2 diff --git a/public/docs/_examples/dependency-injection/dart/lib/app_component.dart b/public/docs/_examples/dependency-injection/dart/lib/app_component.dart index 1a9e4f075b..cb29545084 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/app_component.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/app_component.dart @@ -1,6 +1,3 @@ -// #docplaster -// #docregion -// #docregion imports import 'package:angular2/core.dart'; import 'app_config.dart'; @@ -8,9 +5,8 @@ import 'car/car_component.dart'; import 'heroes/heroes_component.dart'; import 'logger_service.dart'; import 'user_service.dart'; -//PENDING: check whether we intend to hide injector_component.dart & providers_component.dart; if so, change docregion name? -// #enddocregion imports import 'injector_component.dart'; +import 'test_component.dart'; import 'providers_component.dart'; @Component( @@ -31,21 +27,21 @@ import 'providers_component.dart'; CarComponent, HeroesComponent, InjectorComponent, + TestComponent, ProvidersComponent ], -// #docregion providers + // #docregion providers providers: const [ - Logger, - UserService, - const Provider(AppConfig, useValue: config1)] -// #enddocregion providers + Logger, UserService, + const Provider(APP_CONFIG, useFactory: heroDiConfigFactory)] + // #enddocregion providers ) class AppComponent { final UserService _userService; final String title; - //#docregion ctor - AppComponent(AppConfig config, this._userService) + // #docregion ctor + AppComponent(@Inject(APP_CONFIG) AppConfig config, this._userService) : title = config.title; // #enddocregion ctor @@ -61,7 +57,6 @@ class AppComponent { return _userService.user; } - String get userInfo => 'Current user, ${user.name}, is' - '${isAuthorized ? "" : " not"} authorized. '; + String get userInfo => 'Current user, ${user.name}, is' + + (isAuthorized ? '' : ' not') + ' authorized. '; } -// #enddocregion diff --git a/public/docs/_examples/dependency-injection/dart/lib/app_component_1.dart b/public/docs/_examples/dependency-injection/dart/lib/app_component_1.dart index 2466b4894b..ad1527f131 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/app_component_1.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/app_component_1.dart @@ -16,13 +16,3 @@ import 'heroes/heroes_component_1.dart'; class AppComponent { final String title = 'Dependency Injection'; } -// #enddocregion - -/* -//#docregion ctor-di-fail -// FAIL! Injectable `config` is not a class! -AppComponent(HeroService heroService, Map config) { - title = config['title']; -} -//#enddocregion ctor-di-fail -*/ diff --git a/public/docs/_examples/dependency-injection/dart/lib/app_component_2.dart b/public/docs/_examples/dependency-injection/dart/lib/app_component_2.dart index 4463b7c59c..6017a9019f 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/app_component_2.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/app_component_2.dart @@ -21,13 +21,16 @@ import 'logger_service.dart'; ], providers: const [ Logger, - const Provider(AppConfig, useValue: config1) - ]) + // #docregion providers + const Provider(APP_CONFIG, useValue: heroDiConfig) + // #enddocregion providers + ] +) class AppComponent { final String title; // #docregion ctor - AppComponent(AppConfig config) - : title = config.title; - // #enddocregion + AppComponent(@Inject(APP_CONFIG) Map config) + : title = config['title']; + // #enddocregion ctor } diff --git a/public/docs/_examples/dependency-injection/dart/lib/app_config.dart b/public/docs/_examples/dependency-injection/dart/lib/app_config.dart index 7785eff1b4..faadf62126 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/app_config.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/app_config.dart @@ -1,17 +1,27 @@ -// #docregion // #docregion token import 'package:angular2/core.dart'; -//#docregion const-class -@Injectable() +const APP_CONFIG = const OpaqueToken('app.config'); +// #enddocregion token + +// #docregion config +const Map heroDiConfig = const { + 'apiEndpoint' : 'api.heroes.com', + 'title' : 'Dependency Injection' +}; +// #enddocregion config + +// #docregion config-alt class AppConfig { - final apiEndpoint; - final String title; - - const AppConfig(this.apiEndpoint, this.title); + String apiEndpoint; + String title; } -//#enddocregion const-class -//#docregion const-object -const config1 = const AppConfig('api.heroes.com', 'Dependency Injection'); -//#enddocregion const-object +AppConfig heroDiConfigFactory() => new AppConfig() + ..apiEndpoint = 'api.heroes.com' + ..title = 'Dependency Injection'; +// #enddocregion config-alt + +const appConfigProvider = const Provider(APP_CONFIG, + useFactory: heroDiConfigFactory, + deps: const []); diff --git a/public/docs/_examples/dependency-injection/dart/lib/car/car.dart b/public/docs/_examples/dependency-injection/dart/lib/car/car.dart index cacd0d9b69..ff812c9dfa 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/car/car.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/car/car.dart @@ -1,21 +1,19 @@ -// #docregion import 'package:angular2/core.dart'; @Injectable() -// #docregion engine class Engine { - final int cylinders = 4; + final int cylinders; + + Engine() : cylinders = 4; + Engine.withCylinders(this.cylinders); } -// #enddocregion engine @Injectable() -// #docregion tires class Tires { String make = 'Flintstone'; String model = 'Square'; } -// #enddocregion tires @Injectable() class Car { //#docregion car-ctor @@ -24,11 +22,10 @@ class Car { String description = 'DI'; Car(this.engine, this.tires); - // #enddocregion car-ctor // Method using the engine and tires - String drive() => '$description car with ${engine.cylinders} cylinders' - ' and ${tires.make} tires.'; + String drive() => '$description car with ' + '${engine.cylinders} cylinders and ' + '${tires.make} tires.'; } -// #enddocregion car diff --git a/public/docs/_examples/dependency-injection/dart/lib/car/car_creations.dart b/public/docs/_examples/dependency-injection/dart/lib/car/car_creations.dart index d0e6be3c1c..96674b83f0 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/car/car_creations.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/car/car_creations.dart @@ -3,50 +3,39 @@ import 'car.dart'; ///////// example 1 //////////// -Car simpleCar() { - //#docregion car-ctor-instantiation +Car simpleCar() => + // #docregion car-ctor-instantiation // Simple car with 4 cylinders and Flintstone tires. - var car = new Car(new Engine(), new Tires()); - //#enddocregion car-ctor-instantiation - car.description = 'Simple'; - return car; -} + new Car(new Engine(), new Tires()) + // #enddocregion car-ctor-instantiation + ..description = 'Simple'; + ///////// example 2 //////////// -//#docregion car-ctor-instantiation-with-param -class Engine2 implements Engine { - final int cylinders; - - Engine2(this.cylinders); +// #docregion car-ctor-instantiation-with-param +class Engine2 extends Engine { + Engine2(cylinders) : super.withCylinders(cylinders); } -//#enddocregion car-ctor-instantiation-with-param -Car superCar() { -//#docregion car-ctor-instantiation-with-param -// Super car with 12 cylinders and Flintstone tires. -var bigCylinders = 12; -var car = new Car(new Engine2(bigCylinders), new Tires()); -//#enddocregion car-ctor-instantiation-with-param - car.description = 'Super'; - return car; -} +Car superCar() => + // Super car with 12 cylinders and Flintstone tires. + new Car(new Engine2(12), new Tires()) + ..description = 'Super'; +// #enddocregion car-ctor-instantiation-with-param + /////////// example 3 ////////// -//#docregion car-ctor-instantiation-with-mocks +// #docregion car-ctor-instantiation-with-mocks class MockEngine extends Engine { - final int cylinders = 8; + MockEngine() : super.withCylinders(8); } class MockTires extends Tires { - String make = 'YokoGoodStone'; + MockTires() { make = 'YokoGoodStone'; } } -//#enddocregion car-ctor-instantiation-with-mocks -Car testCar() { -//#docregion car-ctor-instantiation-with-mocks -// Test car with 8 cylinders and YokoGoodStone tires. -var car = new Car(new MockEngine(), new MockTires()); -//#enddocregion car-ctor-instantiation-with-mocks - car.description = 'Test'; - return car; -} +Car testCar() => + // Test car with 8 cylinders and YokoGoodStone tires. + new Car(new MockEngine(), new MockTires()) + ..description = 'Test'; +// #enddocregion car-ctor-instantiation-with-mocks diff --git a/public/docs/_examples/dependency-injection/dart/lib/car/car_factory.dart b/public/docs/_examples/dependency-injection/dart/lib/car/car_factory.dart index 7610e28b14..6107c894b7 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/car/car_factory.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/car/car_factory.dart @@ -3,10 +3,9 @@ import 'car.dart'; // BAD pattern! class CarFactory { - Car createCar() { - return new Car(createEngine(), createTires()) - ..description = 'Factory'; - } + Car createCar() => + new Car(createEngine(), createTires()) + ..description = 'Factory'; Engine createEngine() => new Engine(); Tires createTires() => new Tires(); diff --git a/public/docs/_examples/dependency-injection/dart/lib/car/car_injector.dart b/public/docs/_examples/dependency-injection/dart/lib/car/car_injector.dart index c5502413f6..07d78559eb 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/car/car_injector.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/car/car_injector.dart @@ -1,36 +1,27 @@ -// #docplaster -//#docregion import 'package:angular2/core.dart'; import '../logger_service.dart'; import 'car.dart'; -//#docregion injector +// #docregion injector Car useInjector() { ReflectiveInjector injector; - //#enddocregion injector - + // #enddocregion injector /* -//#docregion injector-no-new - // Cannot 'new' an ReflectiveInjector like this! - var injector = new ReflectiveInjector([Car, Engine, Tires, Logger]); -//#enddocregion injector-no-new -*/ - - //#docregion injector - - //#docregion injector-create-and-call - injector = ReflectiveInjector.resolveAndCreate([Car, Engine, Tires, Logger]); - //#docregion injector-call + // #docregion injector-no-new + // Cannot instantiate an ReflectiveInjector like this! + var injector = new ReflectiveInjector([Car, Engine, Tires]); + // #enddocregion injector-no-new + */ + // #docregion injector, injector-create-and-call + injector = ReflectiveInjector.resolveAndCreate([Car, Engine, Tires]); + // #docregion injector-call var car = injector.get(Car); - //#enddocregion injector-call - //#enddocregion injector-create-and-call - + // #enddocregion injector-call, injector-create-and-call car.description = 'Injector'; + + injector = ReflectiveInjector.resolveAndCreate([Logger]); var logger = injector.get(Logger); logger.log('Injector car.drive() said: ' + car.drive()); return car; } -//#enddocregion injector - -//#enddocregion diff --git a/public/docs/_examples/dependency-injection/dart/lib/car/car_no_di.dart b/public/docs/_examples/dependency-injection/dart/lib/car/car_no_di.dart index 86a4177b2d..7db13b87f0 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/car/car_no_di.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/car/car_no_di.dart @@ -17,6 +17,7 @@ class Car { // Method using the engine and tires String drive() => '$description car with ' - '${engine.cylinders} cylinders and ${tires.make} tires.'; + '${engine.cylinders} cylinders and ' + '${tires.make} tires.'; } //#enddocregion car diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero.dart index 2a76844f9c..369ef1a5fe 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero.dart @@ -1,6 +1,8 @@ // #docregion class Hero { - num id; - String name; - bool isSecret = false; + final int id; + final String name; + final bool isSecret; + + Hero(this.id, this.name, [this.isSecret = false]); } diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component.dart index 96d541762d..829fd60bec 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component.dart @@ -14,7 +14,8 @@ import 'hero_service.dart'; class HeroListComponent { final List heroes; -//#docregion ctor-signature - HeroListComponent(HeroService heroService) : heroes = heroService.getHeroes(); -//#enddocregion ctor-signature + // #docregion ctor-signature + HeroListComponent(HeroService heroService) + // #enddocregion ctor-signature + : heroes = heroService.getHeroes(); } diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component_2.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component_2.dart index d120cfa892..6a85c0a5d5 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component_2.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_list_component_2.dart @@ -1,8 +1,16 @@ +// #docplaster // #docregion import 'package:angular2/core.dart'; import 'hero.dart'; +// #enddocregion +import 'hero_service_1.dart'; +/* +// #docregion import 'hero_service.dart'; +// #enddocregion +*/ +// #docregion @Component( selector: 'hero-list', @@ -13,8 +21,8 @@ import 'hero_service.dart'; class HeroListComponent { final List heroes; -//#docregion ctor + // #docregion ctor HeroListComponent(HeroService heroService) : heroes = heroService.getHeroes(); -//#enddocregion ctor + // #enddocregion ctor } diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service.dart index 59074e3cd4..f66bd7ef6d 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service.dart @@ -20,5 +20,5 @@ class HeroService { .where((hero) => _isAuthorized || !hero.isSecret) .toList(); } -// #enddocregion internals + // #enddocregion internals } diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_1.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_1.dart index f400d86fc4..666c2a2815 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_1.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_1.dart @@ -1,7 +1,10 @@ // #docregion +import 'package:angular2/core.dart'; + import 'hero.dart'; import 'mock_heroes.dart'; +@Injectable() class HeroService { List getHeroes() => HEROES; } diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_2.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_2.dart index badd8f548e..b4ef2a2a41 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_2.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_2.dart @@ -11,7 +11,6 @@ class HeroService { //#docregion ctor HeroService(this._logger); - //#enddocregion ctor List getHeroes() { _logger.log('Getting heroes ...'); diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_provider.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_provider.dart index 7e457e2db9..1dd52cf3e2 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_provider.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service_provider.dart @@ -6,8 +6,7 @@ import '../user_service.dart'; import 'hero_service.dart'; // #docregion factory -@Injectable() -heroServiceFactory(Logger logger, UserService userService) => +HeroService heroServiceFactory(Logger logger, UserService userService) => new HeroService(logger, userService.user.isAuthorized); // #enddocregion factory diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/heroes_component_1.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/heroes_component_1.dart index 19cde705ce..4546a7c5c3 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/heroes_component_1.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/heroes_component_1.dart @@ -1,23 +1,27 @@ // #docplaster // #docregion -// #docregion v1 +// #docregion full, v1 import 'package:angular2/core.dart'; +// #enddocregion full, v1 +import 'hero_list_component_2.dart'; +import 'hero_service_1.dart'; +/* +// #docregion full import 'hero_list_component.dart'; -// #enddocregion v1 -import 'hero_service.dart'; // #docregion v1 +import 'hero_service.dart'; +// #enddocregion full, v1 +*/ +// #docregion full, v1 @Component( selector: 'my-heroes', template: '''

Heroes

''', -// #enddocregion v1 -// #docregion providers + // #enddocregion v1 providers: const [HeroService], -// #enddocregion providers -// #docregion v1 + // #docregion v1 directives: const [HeroListComponent]) class HeroesComponent {} -// #enddocregion v1 diff --git a/public/docs/_examples/dependency-injection/dart/lib/heroes/mock_heroes.dart b/public/docs/_examples/dependency-injection/dart/lib/heroes/mock_heroes.dart index 2501f92081..70a38c878d 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/heroes/mock_heroes.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/heroes/mock_heroes.dart @@ -1,45 +1,18 @@ // #docregion import 'hero.dart'; -List HEROES = [ - new Hero() - ..id = 11 - ..isSecret = false - ..name = 'Mr. Nice', - new Hero() - ..id = 12 - ..isSecret = false - ..name = 'Narco', - new Hero() - ..id = 13 - ..isSecret = false - ..name = 'Bombasto', - new Hero() - ..id = 14 - ..isSecret = false - ..name = 'Celeritas', - new Hero() - ..id = 15 - ..isSecret = false - ..name = 'Magneta', - new Hero() - ..id = 16 - ..isSecret = false - ..name = 'RubberMan', - new Hero() - ..id = 17 - ..isSecret = false - ..name = 'Dynama', - new Hero() - ..id = 18 - ..isSecret = true - ..name = 'Dr IQ', - new Hero() - ..id = 19 - ..isSecret = true - ..name = 'Magma', - new Hero() - ..id = 20 - ..isSecret = true - ..name = 'Tornado' -]; +List HEROES = [ + {'id': 11, 'isSecret': false, 'name': 'Mr. Nice'}, + {'id': 12, 'isSecret': false, 'name': 'Narco'}, + {'id': 13, 'isSecret': false, 'name': 'Bombasto'}, + {'id': 14, 'isSecret': false, 'name': 'Celeritas'}, + {'id': 15, 'isSecret': false, 'name': 'Magneta'}, + {'id': 16, 'isSecret': false, 'name': 'RubberMan'}, + {'id': 17, 'isSecret': false, 'name': 'Dynama'}, + {'id': 18, 'isSecret': true, 'name': 'Dr IQ'}, + {'id': 19, 'isSecret': true, 'name': 'Magma'}, + {'id': 20, 'isSecret': true, 'name': 'Tornado'} +].map(_initHero).toList(); + +Hero _initHero(Map heroProperties) => new Hero( + heroProperties['id'], heroProperties['name'], heroProperties['isSecret']); diff --git a/public/docs/_examples/dependency-injection/dart/lib/injector_component.dart b/public/docs/_examples/dependency-injection/dart/lib/injector_component.dart index aba047cf75..477bc3bc6c 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/injector_component.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/injector_component.dart @@ -1,6 +1,6 @@ // #docplaster -//#docregion +// #docregion import 'package:angular2/core.dart'; import 'car/car.dart'; @@ -9,7 +9,7 @@ import 'heroes/hero_service.dart'; import 'heroes/hero_service_provider.dart'; import 'logger_service.dart'; -//#docregion injector +// #docregion injector @Component( selector: 'my-injectors', template: ''' @@ -18,39 +18,26 @@ import 'logger_service.dart';
{{hero.name}}
{{rodent}}
''', providers: const [ - Car, - Engine, - Tires, - const Provider(HeroService, useFactory: heroServiceFactory), - Logger - ]) + Car, Engine, Tires, heroServiceProvider, Logger]) class InjectorComponent { final Injector _injector; Car car; HeroService heroService; Hero hero; - String get rodent { - try { - _injector.get(ROUS); - } on NoProviderError { - return "R.O.U.S.'s? I don't think they exist!"; - } - throw new Exception('Aaaargh!'); - } - InjectorComponent(this._injector) { car = _injector.get(Car); - //#docregion get-hero-service + // #docregion get-hero-service heroService = _injector.get(HeroService); - //#enddocregion get-hero-service + // #enddocregion get-hero-service hero = heroService.getHeroes()[0]; } -} -//#enddocregion injector -/** - * R.O.U.S. - Rodents Of Unusual Size - * // https://www.youtube.com/watch?v=BOv5ZjAOpC8 - */ + String get rodent => + _injector.get(ROUS, "R.O.U.S.'s? I don't think they exist!"); +} +// #enddocregion injector + +/// R.O.U.S. - Rodents Of Unusual Size +/// https://www.youtube.com/watch?v=BOv5ZjAOpC8 class ROUS {} diff --git a/public/docs/_examples/dependency-injection/dart/lib/logger_service.dart b/public/docs/_examples/dependency-injection/dart/lib/logger_service.dart index 38b4450f25..ac1e87fa10 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/logger_service.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/logger_service.dart @@ -3,10 +3,11 @@ import 'package:angular2/core.dart'; @Injectable() class Logger { - List logs = []; + List _logs = []; + List get logs => _logs; void log(String message) { - logs.add(message); + _logs.add(message); print(message); } } diff --git a/public/docs/_examples/dependency-injection/dart/lib/providers_component.dart b/public/docs/_examples/dependency-injection/dart/lib/providers_component.dart index 34a1c82f3e..898ad1b001 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/providers_component.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/providers_component.dart @@ -1,6 +1,5 @@ // Examples of provider arrays - -//#docplaster +// #docplaster import 'package:angular2/core.dart'; import 'app_config.dart'; @@ -9,20 +8,22 @@ import 'heroes/hero_service.dart'; import 'logger_service.dart'; import 'user_service.dart'; +// TODO file an issue: cannot use the following const in metadata. +const template = '{{log}}'; + @Component( selector: 'provider-1', template: '{{log}}', - providers: -//#docregion providers-1 - const [Logger] -//#enddocregion providers-1 + // #docregion providers-1, providers-logger + providers: const [Logger] + // #enddocregion providers-1, providers-logger ) class ProviderComponent1 { String log; ProviderComponent1(Logger logger) { logger.log('Hello from logger provided with Logger class'); - log = logger.logs.last; + log = logger.logs[0]; } } @@ -30,29 +31,46 @@ class ProviderComponent1 { selector: 'provider-2', template: '{{log}}', providers: -//#docregion providers-2 - const [const Provider(Logger, useClass: Logger)] -//#enddocregion providers-2 + // #docregion providers-2 + const [const Provider(Logger, useClass: Logger)] + // #enddocregion providers-2 ) class ProviderComponent2 { String log; ProviderComponent2(Logger logger) { logger.log('Hello from logger provided with Provider class and useClass'); - log = logger.logs.last; + log = logger.logs[0]; } } +/// Component just used to ensure that shared E2E tests pass. @Component( - selector: 'provider-3', - template: '{{log}}', - providers: const [const Provider(Logger, useClass: Logger)]) + selector: 'provider-3', + template: '{{log}}', + providers: const [const Provider(Logger, useClass: Logger)] +) class ProviderComponent3 { String log; ProviderComponent3(Logger logger) { logger.log('Hello from logger provided with useClass'); - log = logger.logs.last; + log = logger.logs[0]; + } +} + +/// Component just used to ensure that shared E2E tests pass. +@Component( + selector: 'provider-3a', + template: '{{log}}', + providers: const [const Provider(Logger, useClass: Logger)] +) +class ProviderComponent3a { + String log; + + ProviderComponent3a(Logger logger) { + logger.log('Hello from logger provided with {provide: Logger, useClass: Logger}'); + log = logger.logs[0]; } } @@ -63,58 +81,55 @@ class BetterLogger extends Logger {} selector: 'provider-4', template: '{{log}}', providers: -//#docregion providers-4 - const [const Provider(Logger, useClass: BetterLogger)] -//#enddocregion providers-4 + // #docregion providers-4 + const [const Provider(Logger, useClass: BetterLogger)] + // #enddocregion providers-4 ) class ProviderComponent4 { String log; ProviderComponent4(Logger logger) { logger.log('Hello from logger provided with useClass:BetterLogger'); - log = logger.logs.last; + log = logger.logs[0]; } } // #docregion EvenBetterLogger @Injectable() -class EvenBetterLogger implements Logger { +class EvenBetterLogger extends Logger { final UserService _userService; - @override List logs = []; EvenBetterLogger(this._userService); @override void log(String message) { - var msg = 'Message to ${_userService.user.name}: $message.'; - print(msg); - logs.add(msg); + var name = _userService.user.name; + super.log('Message to $name: $message'); } } - // #enddocregion EvenBetterLogger + @Component( selector: 'provider-5', template: '{{log}}', providers: -//#docregion providers-5 - const [UserService, const Provider(Logger, useClass: EvenBetterLogger)] -//#enddocregion providers-5 + // #docregion providers-5 + const [UserService, const Provider(Logger, useClass: EvenBetterLogger)] + // #enddocregion providers-5 ) class ProviderComponent5 { String log; ProviderComponent5(Logger logger) { logger.log('Hello from EvenBetterlogger'); - log = logger.logs.last; + log = logger.logs[0]; } } @Injectable() class NewLogger extends Logger implements OldLogger {} -class OldLogger { - List logs = []; - +class OldLogger extends Logger { + @override void log(String message) { throw new Exception('Should not call the old logger!'); } @@ -124,26 +139,23 @@ class OldLogger { selector: 'provider-6a', template: '{{log}}', providers: - //#docregion providers-6a - const [NewLogger, - // Not aliased! Creates two instances of `NewLogger` - const Provider(OldLogger, useClass: NewLogger)] - //#enddocregion providers-6a + // #docregion providers-6a + const [NewLogger, + // Not aliased! Creates two instances of `NewLogger` + const Provider(OldLogger, useClass: NewLogger)] + // #enddocregion providers-6a ) class ProviderComponent6a { String log; ProviderComponent6a(NewLogger newLogger, OldLogger oldLogger) { - if (identical(newLogger, oldLogger)) { + if (newLogger == oldLogger) { throw new Exception('expected the two loggers to be different instances'); } oldLogger.log('Hello OldLogger (but we want NewLogger)'); // The newLogger wasn't called so no logs[] - // display the logs of the oldLogger. - log = newLogger.logs == null || newLogger.logs.isEmpty - ? oldLogger.logs[0] - : newLogger.logs[0]; + log = newLogger.logs.isEmpty ? oldLogger.logs[0] : newLogger.logs[0]; } } @@ -151,17 +163,17 @@ class ProviderComponent6a { selector: 'provider-6b', template: '{{log}}', providers: - //#docregion providers-6b - const [NewLogger, - // Alias OldLogger with reference to NewLogger - const Provider(OldLogger, useExisting: NewLogger)] - //#enddocregion providers-6b + // #docregion providers-6b + const [NewLogger, + // Alias OldLogger with reference to NewLogger + const Provider(OldLogger, useExisting: NewLogger)] + // #enddocregion providers-6b ) class ProviderComponent6b { String log; ProviderComponent6b(NewLogger newLogger, OldLogger oldLogger) { - if (!identical(newLogger, oldLogger)) { + if (newLogger != oldLogger) { throw new Exception('expected the two loggers to be the same instance'); } oldLogger.log('Hello from NewLogger (via aliased OldLogger)'); @@ -169,140 +181,102 @@ class ProviderComponent6b { } } -// #docregion opaque-token -const loggerPrefix = const OpaqueToken('Logger prefix'); -// #enddocregion opaque-token +// #docregion silent-logger +// #docregion const-class +class SilentLogger implements Logger { + @override + final List logs = const ['Silent logger says "Shhhhh!". Provided via "useValue"']; -// #docregion configurable-logger -@Injectable() -class ConfigurableLogger extends Logger { - final String _prefix; - -// #docregion use-opaque-token - ConfigurableLogger(@Inject(loggerPrefix) this._prefix); -// #enddocregion use-opaque-token + const SilentLogger(); @override - void log(String msg) { - super.log('$_prefix: $msg'); - } + void log(String message) { } } -// #enddocregion configurable-logger +// #enddocregion const-class +// #docregion const-object -@Component(selector: 'provider-7', template: '{{message}}', -//#docregion providers-7 -providers: const [ - const Provider(Logger, useClass: ConfigurableLogger), -//#docregion providers-usevalue - const Provider(loggerPrefix, useValue: 'Testing') -//#enddocregion providers-usevalue -] -//#enddocregion providers-7 +const silentLogger = const SilentLogger(); +// #enddocregion const-object +// #enddocregion silent-logger + +@Component( + selector: 'provider-7', + template: '{{log}}', + providers: + // #docregion providers-7 + const [const Provider(Logger, useValue: silentLogger)] + // #enddocregion providers-7 ) class ProviderComponent7 { - String message; + String log; ProviderComponent7(Logger logger) { - logger.log('Hello from configurable logger.'); - message = logger.logs.last; + logger.log('Hello from logger provided with useValue'); + log = logger.logs[0]; } } -@Component(selector: 'provider-8', template: '{{log}}', providers: const [ - const Provider(HeroService, useFactory: heroServiceFactory), - Logger, - UserService -]) -class ProviderComponent8 { - // #docregion provider-8-ctor - ProviderComponent8(HeroService heroService); - - // #enddocregion provider-8-ctor - - // must be true else this component would have blown up at runtime - var log = 'Hero service injected successfully'; -} - @Component( - selector: 'provider-9', - template: '{{log}}', - providers: -// #docregion providers-9 -const [const Provider(AppConfig, useValue: config1)] -// #enddocregion providers-9 + selector: 'provider-8', + template: '{{log}}', + providers: const [heroServiceProvider, Logger, UserService]) +class ProviderComponent8 { + // #docregion provider-8-ctor + ProviderComponent8(HeroService heroService); + // #enddocregion provider-8-ctor + + // must be true else this component would have blown up at runtime + var log = 'Hero service injected successfully via heroServiceProvider'; +} + +@Component( + selector: 'provider-9', + template: '{{log}}', + // #docregion providers-9 + providers: const [ + const Provider(APP_CONFIG, useValue: heroDiConfig)] + // #enddocregion providers-9 ) class ProviderComponent9 implements OnInit { - AppConfig _config; + Map _config; String log; - ProviderComponent9(AppConfig this._config); + // #docregion provider-9-ctor + ProviderComponent9(@Inject(APP_CONFIG) this._config); + // #enddocregion provider-9-ctor @override void ngOnInit() { - log = 'appConfigToken Application title is ${_config.title}'; + log = 'APP_CONFIG Application title is ${_config['title']}'; } } -// Normal required logger -@Component(selector: 'provider-10a', template: '{{log}}', -//#docregion providers-logger - providers: const [Logger] -//#enddocregion providers-logger - ) -class ProviderComponent10a { - String log; - - ProviderComponent10a(Logger logger) { - logger.log('Hello from the required logger.'); - log = logger.logs.last; - } -} - -// Optional logger, can be null -@Component(selector: 'provider-10b', template: '{{log}}') -class ProviderComponent10b { - // #docregion provider-10-ctor +// Sample providers 1 to 7 illustrate a required logger dependency. +// Optional logger, can be null. +@Component(selector: 'provider-10', template: '{{log}}') +class ProviderComponent10 implements OnInit { final Logger _logger; String log; - ProviderComponent10b(@Optional() Logger this._logger) { - // . . . - // #enddocregion provider-10-ctor - _logger == null ? log = 'No logger exists' : log = _logger.logs.last; + /* // #docregion provider-10-ctor + HeroService(@Optional() this._logger) { + // #enddocregion provider-10-ctor + */ + ProviderComponent10(@Optional() this._logger) { + const someMessage = 'Hello from the injected logger'; + // #docregion provider-10-ctor + if (_logger != null) + _logger.log(someMessage); } // #enddocregion provider-10-ctor -} -// Optional logger, non null -@Component(selector: 'provider-10c', template: '{{log}}') -class ProviderComponent10c { - // #docregion provider-10-logger - final Logger _logger; - String log; - - ProviderComponent10c(@Optional() Logger logger) : - _logger = logger ?? new DoNothingLogger() { - // . . . - // #enddocregion provider-10-logger - logger == null - ? _logger.log('Optional logger was not available.') - : _logger.log('Hello from the injected logger.'); - log = _logger.logs.last; - // #docregion provider-10-logger + @override + void ngOnInit() { + log = _logger == null ? 'Optional logger was not available' : _logger.logs[0]; } -// #enddocregion provider-10-logger } -// #docregion provider-10-logger -// . . . -@Injectable() -class DoNothingLogger extends Logger { - @override List logs = []; - @override void log(String msg) => logs.add(msg); -} -// #enddocregion provider-10-logger - @Component( selector: 'my-providers', template: ''' @@ -310,20 +284,20 @@ class DoNothingLogger extends Logger {
+
-
-
-
-
''', +
+
''', directives: const [ ProviderComponent1, ProviderComponent2, ProviderComponent3, + ProviderComponent3a, ProviderComponent4, ProviderComponent5, ProviderComponent6a, @@ -331,8 +305,6 @@ class DoNothingLogger extends Logger { ProviderComponent7, ProviderComponent8, ProviderComponent9, - ProviderComponent10a, - ProviderComponent10b, - ProviderComponent10c + ProviderComponent10 ]) class ProvidersComponent {} diff --git a/public/docs/_examples/dependency-injection/dart/lib/test_component.dart b/public/docs/_examples/dependency-injection/dart/lib/test_component.dart new file mode 100644 index 0000000000..24920bd7d2 --- /dev/null +++ b/public/docs/_examples/dependency-injection/dart/lib/test_component.dart @@ -0,0 +1,65 @@ +// Simulate a simple test +// Reader should look to the testing chapter for the real thing + +import 'package:angular2/core.dart'; + +import 'heroes/hero.dart'; +import 'heroes/hero_list_component.dart'; +import 'heroes/hero_service.dart'; + +@Component( + selector: 'my-tests', + template: ''' +

Tests

+

Tests {{results['pass']}}: {{results['message']}}

+ ''') +class TestComponent { + var results = runTests(); +} + +class MockHeroService implements HeroService { + final List _heroes; + MockHeroService(this._heroes); + + @override + List getHeroes() => _heroes; +} + +///////////////////////////////////// +dynamic runTests() { + //#docregion spec + var expectedHeroes = [new Hero(0, 'A'), new Hero(1, 'B')]; + var mockService = new MockHeroService(expectedHeroes); + it('should have heroes when HeroListComponent created', () { + var hlc = new HeroListComponent(mockService); + expect(hlc.heroes.length).toEqual(expectedHeroes.length); + }); + //#enddocregion spec + return testResults; +} +////////////////////////////////// + +// Fake Jasmine infrastructure +String testName; +dynamic testResults; +dynamic expect(dynamic actual) => new ExpectResult(actual); + +class ExpectResult { + final actual; + ExpectResult(this.actual); + + void toEqual(dynamic expected) { + testResults = actual == expected + ? {'pass': 'passed', 'message': testName} + : { + 'pass': 'failed', + 'message': '$testName; expected $actual to equal $expected.' + }; + } +} + +void it(String label, void test()) { + testName = label; + test(); +} + diff --git a/public/docs/_examples/dependency-injection/dart/lib/user_service.dart b/public/docs/_examples/dependency-injection/dart/lib/user_service.dart index 5b6cabf960..24b61468db 100644 --- a/public/docs/_examples/dependency-injection/dart/lib/user_service.dart +++ b/public/docs/_examples/dependency-injection/dart/lib/user_service.dart @@ -1,26 +1,23 @@ // #docregion import 'package:angular2/core.dart'; -@Injectable() -class UserService { - UserService() { - user = _bob; - } - - // Todo: get the user; don't 'new' it. - User _alice = new User('Alice', true); - User _bob = new User('Bob', false); - - // initial user is Bob - User user; - - // swaps users - User getNewUser() => user = user == _bob ? _alice : _bob; -} - class User { - String name; - bool isAuthorized; + final String name; + final bool isAuthorized; User(this.name, [this.isAuthorized = false]); } + +// Todo: get the user; don't 'new' it. +final User _alice = new User('Alice', true); +final User _bob = new User('Bob', false); + +@Injectable() +class UserService { + User user; + + UserService() : user = _bob; + + // swap users + User getNewUser() => user = user == _bob ? _alice : _bob; +} diff --git a/public/docs/_examples/dependency-injection/dart/test/hero_list_component_test.dart b/public/docs/_examples/dependency-injection/dart/test/hero_list_component_test.dart index 1c45babc68..4936a3e7f8 100644 --- a/public/docs/_examples/dependency-injection/dart/test/hero_list_component_test.dart +++ b/public/docs/_examples/dependency-injection/dart/test/hero_list_component_test.dart @@ -9,13 +9,8 @@ import 'package:test/test.dart'; /////////////////////////////////////// ////#docregion spec List expectedHeroes = [ - new Hero() - ..id = 1 - ..name = 'hero1', - new Hero() - ..id = 2 - ..name = 'hero2' - ..isSecret = true + new Hero(1, 'hero1'), + new Hero(2, 'hero2', true) ]; class HeroServiceMock implements HeroService { diff --git a/public/docs/_examples/dependency-injection/dart/web/main.dart b/public/docs/_examples/dependency-injection/dart/web/main.dart index abc5a9c88e..5ec8717ed2 100644 --- a/public/docs/_examples/dependency-injection/dart/web/main.dart +++ b/public/docs/_examples/dependency-injection/dart/web/main.dart @@ -1,10 +1,9 @@ -//#docregion import 'package:angular2/platform/browser.dart'; import 'package:dependency_injection/app_component.dart'; import 'package:dependency_injection/providers_component.dart'; -main() { +void main() { //#docregion bootstrap bootstrap(AppComponent); //#enddocregion bootstrap diff --git a/public/docs/_examples/dependency-injection/dart/web/main_1.dart b/public/docs/_examples/dependency-injection/dart/web/main_1.dart index b621869c60..561c6ba946 100644 --- a/public/docs/_examples/dependency-injection/dart/web/main_1.dart +++ b/public/docs/_examples/dependency-injection/dart/web/main_1.dart @@ -1,10 +1,21 @@ -import 'package:angular2/platform/browser.dart'; -import 'package:dependency_injection/app_component.dart'; -import 'package:dependency_injection/heroes/hero_service.dart'; +// **WARNING** +// To try out this version of the app, ensure that you update: +// - web/index.html +// - pubspec.yaml +// to refer to this file instead of main.dart -main() { - //#docregion bootstrap - bootstrap(AppComponent, - [HeroService]); // DISCOURAGED (but works) - //#enddocregion bootstrap +import 'package:angular2/platform/browser.dart'; + +import 'package:dependency_injection/app_component_1.dart'; +import 'package:dependency_injection/heroes/hero_service_1.dart'; + +void main() { + bootstrap(AppComponent); +} + +void main_alt() { + // #docregion bootstrap-discouraged + bootstrap(AppComponent, + [HeroService]); // DISCOURAGED (but works) + // #enddocregion bootstrap-discouraged } diff --git a/public/docs/_examples/dependency-injection/e2e-spec.ts b/public/docs/_examples/dependency-injection/e2e-spec.ts index 5656bddc6d..5e8fd38db8 100644 --- a/public/docs/_examples/dependency-injection/e2e-spec.ts +++ b/public/docs/_examples/dependency-injection/e2e-spec.ts @@ -101,7 +101,7 @@ describe('Dependency Injection Tests', function () { }); it('P5 (useClass:EvenBetterLogger - dependency) displays as expected', function () { - expectedMsg = 'Message to Bob: Hello from EvenBetterlogger.'; + expectedMsg = 'Message to Bob: Hello from EvenBetterlogger'; expect(element(by.css('#p5')).getText()).toEqual(expectedMsg); }); @@ -121,28 +121,18 @@ describe('Dependency Injection Tests', function () { }); it('P8 (useFactory) displays as expected', function () { - expectedMsg = 'Hero service injected successfully'; + expectedMsg = 'Hero service injected successfully via heroServiceProvider'; expect(element(by.css('#p8')).getText()).toEqual(expectedMsg); }); - it('P9a (string token) displays as expected', function () { - expectedMsg = '"app.config" Application title is Dependency Injection'; - expect(element(by.css('#p9a')).getText()).toEqual(expectedMsg); - }); - - it('P9b (OpaqueToken) displays as expected', function () { + it('P9 (OpaqueToken) displays as expected', function () { expectedMsg = 'APP_CONFIG Application title is Dependency Injection'; - expect(element(by.css('#p9b')).getText()).toEqual(expectedMsg); + expect(element(by.css('#p9')).getText()).toEqual(expectedMsg); }); - it('P10a (required dependency) displays as expected', function () { - expectedMsg = 'Hello from the required logger.'; - expect(element(by.css('#p10a')).getText()).toEqual(expectedMsg); - }); - - it('P10b (optional dependency) displays as expected', function () { - expectedMsg = 'Optional logger was not available.'; - expect(element(by.css('#p10b')).getText()).toEqual(expectedMsg); + it('P10 (optional dependency) displays as expected', function () { + expectedMsg = 'Optional logger was not available'; + expect(element(by.css('#p10')).getText()).toEqual(expectedMsg); }) }); diff --git a/public/docs/_examples/dependency-injection/ts/app/app.component.1.ts b/public/docs/_examples/dependency-injection/ts/app/app.component.1.ts index 2e16a385dd..bec40f397d 100644 --- a/public/docs/_examples/dependency-injection/ts/app/app.component.1.ts +++ b/public/docs/_examples/dependency-injection/ts/app/app.component.1.ts @@ -19,14 +19,3 @@ import { HeroesComponent } from './heroes/heroes.component.1'; export class AppComponent { title = 'Dependency Injection'; } -// #enddocregion - - -/* -//#docregion ctor-di-fail -// FAIL! Injectable `config` is not a class! -constructor(heroService: HeroService, config: config) { - this.title = config.title; -} -//#enddocregion ctor-di-fail -*/ diff --git a/public/docs/_examples/dependency-injection/ts/app/app.component.2.ts b/public/docs/_examples/dependency-injection/ts/app/app.component.2.ts index b2c17c90ae..582eb7474b 100644 --- a/public/docs/_examples/dependency-injection/ts/app/app.component.2.ts +++ b/public/docs/_examples/dependency-injection/ts/app/app.component.2.ts @@ -5,7 +5,8 @@ import { CarComponent } from './car/car.component'; import { HeroesComponent } from './heroes/heroes.component.1'; import { provide, Inject } from '@angular/core'; -import { Config, CONFIG } from './app.config'; +import { APP_CONFIG, AppConfig, + HERO_DI_CONFIG } from './app.config'; import { Logger } from './logger.service'; // #enddocregion imports @@ -17,23 +18,19 @@ import { Logger } from './logger.service'; `, directives:[CarComponent, HeroesComponent], -// #docregion providers providers: [ Logger, - // #docregion provider-config - provide('app.config', {useValue: CONFIG}) - // #enddocregion provider-config + // #docregion providers + provide(APP_CONFIG, {useValue: HERO_DI_CONFIG}) + // #enddocregion providers ] -// #docregion providers }) export class AppComponent { title:string; // #docregion ctor - constructor(@Inject('app.config') config:Config) { - + constructor(@Inject(APP_CONFIG) config:AppConfig) { this.title = config.title; } - // #docregion ctor + // #enddocregion ctor } -// #enddocregion diff --git a/public/docs/_examples/dependency-injection/ts/app/app.component.ts b/public/docs/_examples/dependency-injection/ts/app/app.component.ts index 30f2f5f303..1d7481a19f 100644 --- a/public/docs/_examples/dependency-injection/ts/app/app.component.ts +++ b/public/docs/_examples/dependency-injection/ts/app/app.component.ts @@ -6,8 +6,8 @@ import { Component, Inject, provide } from '@angular/core'; import { CarComponent } from './car/car.component'; import { HeroesComponent } from './heroes/heroes.component'; -import { APP_CONFIG, - Config, CONFIG } from './app.config'; +import { APP_CONFIG, AppConfig, + HERO_DI_CONFIG } from './app.config'; import { Logger } from './logger.service'; import { User, UserService } from './user.service'; @@ -33,22 +33,21 @@ import { ProvidersComponent } from './providers.component'; `, directives:[CarComponent, HeroesComponent, InjectorComponent, TestComponent, ProvidersComponent], -// #docregion providers + // #docregion providers providers: [ Logger, UserService, - provide(APP_CONFIG, {useValue: CONFIG}) + provide(APP_CONFIG, {useValue: HERO_DI_CONFIG}) ] -// #enddocregion providers + // #enddocregion providers }) export class AppComponent { title:string; - //#docregion ctor + // #docregion ctor constructor( - @Inject(APP_CONFIG) config:Config, + @Inject(APP_CONFIG) config:AppConfig, private userService: UserService) { - this.title = config.title; } // #enddocregion ctor @@ -62,4 +61,3 @@ export class AppComponent { `${this.isAuthorized ? '' : 'not'} authorized. `; } } -// #enddocregion diff --git a/public/docs/_examples/dependency-injection/ts/app/app.config.ts b/public/docs/_examples/dependency-injection/ts/app/app.config.ts index 0ed6225e86..fcffa83628 100644 --- a/public/docs/_examples/dependency-injection/ts/app/app.config.ts +++ b/public/docs/_examples/dependency-injection/ts/app/app.config.ts @@ -1,4 +1,3 @@ -//#docregion // #docregion token import { OpaqueToken } from '@angular/core'; @@ -6,13 +5,12 @@ export let APP_CONFIG = new OpaqueToken('app.config'); // #enddocregion token //#docregion config -export interface Config { +export interface AppConfig { apiEndpoint: string, title: string } -export const CONFIG:Config = { +export const HERO_DI_CONFIG: AppConfig = { apiEndpoint: 'api.heroes.com', title: 'Dependency Injection' }; -//#enddocregion config \ No newline at end of file diff --git a/public/docs/_examples/dependency-injection/ts/app/car/car-injector.ts b/public/docs/_examples/dependency-injection/ts/app/car/car-injector.ts index d8e23efe36..04d379785f 100644 --- a/public/docs/_examples/dependency-injection/ts/app/car/car-injector.ts +++ b/public/docs/_examples/dependency-injection/ts/app/car/car-injector.ts @@ -1,37 +1,27 @@ -// #docplaster -//#docregion -import { ReflectiveInjector } from '@angular/core'; +import { ReflectiveInjector } from '@angular/core'; import { Car, Engine, Tires } from './car'; import { Logger } from '../logger.service'; -//#docregion injector +// #docregion injector export function useInjector() { - var injector:ReflectiveInjector; - -//#enddocregion injector -/* -//#docregion injector-no-new - // Cannot 'new' an ReflectiveInjector like this! - var injector = new ReflectiveInjector([Car, Engine, Tires, Logger]); -//#enddocregion injector-no-new -*/ - -//#docregion injector - //#docregion injector-create-and-call - injector = ReflectiveInjector.resolveAndCreate([Car, Engine, Tires, Logger]); - //#docregion injector-call + var injector: ReflectiveInjector; + // #enddocregion injector + /* + // #docregion injector-no-new + // Cannot instantiate an ReflectiveInjector like this! + var injector = new ReflectiveInjector([Car, Engine, Tires]); + // #enddocregion injector-no-new + */ + // #docregion injector, injector-create-and-call + injector = ReflectiveInjector.resolveAndCreate([Car, Engine, Tires]); + // #docregion injector-call var car = injector.get(Car); - //#enddocregion injector-call - //#enddocregion injector-create-and-call + // #enddocregion injector-call, injector-create-and-call car.description = 'Injector'; + injector = ReflectiveInjector.resolveAndCreate([Logger]); var logger = injector.get(Logger); logger.log('Injector car.drive() said: '+car.drive()); - return car; } -//#enddocregion injector - - -//#enddocregion diff --git a/public/docs/_examples/dependency-injection/ts/app/car/car.ts b/public/docs/_examples/dependency-injection/ts/app/car/car.ts index dd7c76c0f2..0e4a4a1415 100644 --- a/public/docs/_examples/dependency-injection/ts/app/car/car.ts +++ b/public/docs/_examples/dependency-injection/ts/app/car/car.ts @@ -1,21 +1,15 @@ -// #docregion import { Injectable } from '@angular/core'; -// #docregion engine export class Engine { - public cylinders = 4; // default + public cylinders = 4; } -// #enddocregion engine -// #docregion tires export class Tires { public make = 'Flintstone'; public model = 'Square'; } -// #enddocregion tires @Injectable() -// #docregion car export class Car { //#docregion car-ctor public description = 'DI'; @@ -29,4 +23,3 @@ export class Car { `${this.engine.cylinders} cylinders and ${this.tires.make} tires.` } } -// #enddocregion car diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.1.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.1.ts index a9e0ce66f5..ba32366aa9 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.1.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.1.ts @@ -9,7 +9,7 @@ import { HEROES } from './mock-heroes';
{{hero.id}} - {{hero.name}}
- `, + ` }) export class HeroListComponent { heroes = HEROES; diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.2.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.2.ts index bf0b9be7ff..6b55f78a6e 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.2.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.2.ts @@ -1,8 +1,16 @@ +// #docplaster // #docregion import { Component } from '@angular/core'; import { Hero } from './hero'; +// #enddocregion +import { HeroService } from './hero.service.1'; +/* +// #docregion import { HeroService } from './hero.service'; +// #enddocregion +*/ +// #docregion @Component({ selector: 'hero-list', diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.ts index 3e2cb4579a..e841669661 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/hero-list.component.ts @@ -17,8 +17,9 @@ export class HeroListComponent { heroes: Hero[]; // #docregion ctor-signature - constructor(heroService: HeroService) { + constructor(heroService: HeroService) // #enddocregion ctor-signature + { this.heroes = heroService.getHeroes(); } } diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/hero.service.1.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/hero.service.1.ts index 1edd6b8582..a5a715dbae 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/hero.service.1.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/hero.service.1.ts @@ -1,7 +1,10 @@ // #docregion -import { Hero } from './hero'; -import { HEROES } from './mock-heroes'; +import { Injectable } from '@angular/core'; +import { Hero } from './hero'; +import { HEROES } from './mock-heroes'; + +@Injectable() export class HeroService { getHeroes() { return HEROES; } } diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/heroes.component.1.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/heroes.component.1.ts index 7f431d6d19..247b8c7841 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/heroes.component.1.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/heroes.component.1.ts @@ -1,12 +1,18 @@ // #docplaster -// #docregion -// #docregion v1 +// #docregion full, v1 import { Component } from '@angular/core'; +// #enddocregion full, v1 +import { HeroListComponent } from './hero-list.component.2'; +import { HeroService } from './hero.service.1'; +/* +// #docregion full import { HeroListComponent } from './hero-list.component'; -// #enddocregion v1 -import { HeroService } from './hero.service'; // #docregion v1 +import { HeroService } from './hero.service'; +// #enddocregion full, v1 +*/ +// #docregion full, v1 @Component({ selector: 'my-heroes', @@ -15,11 +21,8 @@ import { HeroService } from './hero.service'; `, // #enddocregion v1 - // #docregion providers providers:[HeroService], - // #enddocregion providers -// #docregion v1 + // #docregion v1 directives:[HeroListComponent] }) export class HeroesComponent { } -// #enddocregion v1 diff --git a/public/docs/_examples/dependency-injection/ts/app/heroes/mock-heroes.ts b/public/docs/_examples/dependency-injection/ts/app/heroes/mock-heroes.ts index 83726eb2f3..98695e90ce 100644 --- a/public/docs/_examples/dependency-injection/ts/app/heroes/mock-heroes.ts +++ b/public/docs/_examples/dependency-injection/ts/app/heroes/mock-heroes.ts @@ -2,14 +2,14 @@ import { Hero } from './hero'; export var HEROES: Hero[] = [ - { "id": 11, isSecret: false, "name": "Mr. Nice" }, - { "id": 12, isSecret: false, "name": "Narco" }, - { "id": 13, isSecret: false, "name": "Bombasto" }, - { "id": 14, isSecret: false, "name": "Celeritas" }, - { "id": 15, isSecret: false, "name": "Magneta" }, - { "id": 16, isSecret: false, "name": "RubberMan" }, - { "id": 17, isSecret: false, "name": "Dynama" }, - { "id": 18, isSecret: true, "name": "Dr IQ" }, - { "id": 19, isSecret: true, "name": "Magma" }, - { "id": 20, isSecret: true, "name": "Tornado" } + { id: 11, isSecret: false, name: "Mr. Nice" }, + { id: 12, isSecret: false, name: "Narco" }, + { id: 13, isSecret: false, name: "Bombasto" }, + { id: 14, isSecret: false, name: "Celeritas" }, + { id: 15, isSecret: false, name: "Magneta" }, + { id: 16, isSecret: false, name: "RubberMan" }, + { id: 17, isSecret: false, name: "Dynama" }, + { id: 18, isSecret: true, name: "Dr IQ" }, + { id: 19, isSecret: true, name: "Magma" }, + { id: 20, isSecret: true, name: "Tornado" } ]; diff --git a/public/docs/_examples/dependency-injection/ts/app/injector.component.ts b/public/docs/_examples/dependency-injection/ts/app/injector.component.ts index 7938a5b8ed..84c8de4a95 100644 --- a/public/docs/_examples/dependency-injection/ts/app/injector.component.ts +++ b/public/docs/_examples/dependency-injection/ts/app/injector.component.ts @@ -1,13 +1,14 @@ // #docplaster -//#docregion +// #docregion import { Component, Injector } from '@angular/core'; import { Car, Engine, Tires } from './car/car'; +import { Hero } from './heroes/hero'; import { HeroService } from './heroes/hero.service'; import { heroServiceProvider } from './heroes/hero.service.provider'; import { Logger } from './logger.service'; -//#docregion injector +// #docregion injector @Component({ selector: 'my-injectors', template: ` @@ -16,29 +17,24 @@ import { Logger } from './logger.service';
{{hero.name}}
{{rodent}}
`, - - providers: [Car, Engine, Tires, - heroServiceProvider, Logger] + providers: [Car, Engine, Tires, heroServiceProvider, Logger] }) export class InjectorComponent { constructor(private injector: Injector) { } - car:Car = this.injector.get(Car); + car: Car = this.injector.get(Car); - //#docregion get-hero-service - heroService:HeroService = this.injector.get(HeroService); - //#enddocregion get-hero-service - hero = this.heroService.getHeroes()[0]; + // #docregion get-hero-service + heroService: HeroService = this.injector.get(HeroService); + // #enddocregion get-hero-service + hero: Hero = this.heroService.getHeroes()[0]; get rodent() { - let rous = this.injector.get(ROUS, null); - if (rous) { - throw new Error('Aaaargh!') - } - return "R.O.U.S.'s? I don't think they exist!"; + let rousDontExist = "R.O.U.S.'s? I don't think they exist!"; + return this.injector.get(ROUS, rousDontExist); } } -//#enddocregion injector +// #enddocregion injector /** * R.O.U.S. - Rodents Of Unusual Size diff --git a/public/docs/_examples/dependency-injection/ts/app/logger.service.ts b/public/docs/_examples/dependency-injection/ts/app/logger.service.ts index 7efb25ba4d..4812ccd3ac 100644 --- a/public/docs/_examples/dependency-injection/ts/app/logger.service.ts +++ b/public/docs/_examples/dependency-injection/ts/app/logger.service.ts @@ -4,7 +4,8 @@ import { Injectable } from '@angular/core'; @Injectable() export class Logger { logs:string[] = []; // capture logs for testing - log(message: string){ + + log(message: string) { this.logs.push(message); console.log(message); } diff --git a/public/docs/_examples/dependency-injection/ts/app/main.1.ts b/public/docs/_examples/dependency-injection/ts/app/main.1.ts index a8c48c2d28..56169511d5 100644 --- a/public/docs/_examples/dependency-injection/ts/app/main.1.ts +++ b/public/docs/_examples/dependency-injection/ts/app/main.1.ts @@ -1,8 +1,12 @@ import { bootstrap } from '@angular/platform-browser-dynamic'; -import { AppComponent } from './app.component'; -import { HeroService } from './heroes/hero.service'; +import { AppComponent } from './app.component.1'; +import { HeroService } from './heroes/hero.service.1'; -//#docregion bootstrap -bootstrap(AppComponent, - [HeroService]); // DISCOURAGED (but works) -//#enddocregion bootstrap +bootstrap(AppComponent); + +function discouraged() { + //#docregion bootstrap-discouraged + bootstrap(AppComponent, + [HeroService]); // DISCOURAGED (but works) + //#enddocregion bootstrap-discouraged +} diff --git a/public/docs/_examples/dependency-injection/ts/app/main.ts b/public/docs/_examples/dependency-injection/ts/app/main.ts index 2919d89387..8e480e8d7f 100644 --- a/public/docs/_examples/dependency-injection/ts/app/main.ts +++ b/public/docs/_examples/dependency-injection/ts/app/main.ts @@ -1,4 +1,3 @@ -//#docregion import { bootstrap } from '@angular/platform-browser-dynamic'; import { AppComponent } from './app.component'; import { ProvidersComponent } from './providers.component'; diff --git a/public/docs/_examples/dependency-injection/ts/app/providers.component.ts b/public/docs/_examples/dependency-injection/ts/app/providers.component.ts index cd718c4c04..7bbc3955b8 100644 --- a/public/docs/_examples/dependency-injection/ts/app/providers.component.ts +++ b/public/docs/_examples/dependency-injection/ts/app/providers.component.ts @@ -4,8 +4,8 @@ import { Component, Inject, Injectable, provide, Provider } from '@angular/core'; -import { APP_CONFIG, - Config, CONFIG } from './app.config'; +import { APP_CONFIG, AppConfig, + HERO_DI_CONFIG } from './app.config'; import { HeroService } from './heroes/hero.service'; import { heroServiceProvider } from './heroes/hero.service.provider'; @@ -18,10 +18,9 @@ let template = '{{log}}'; @Component({ selector: 'provider-1', template: template, - providers: - // #docregion providers-1 - [Logger] - // #enddocregion providers-1 + // #docregion providers-1, providers-logger + providers: [Logger] + // #enddocregion providers-1, providers-logger }) export class ProviderComponent1 { log: string; @@ -104,15 +103,12 @@ export class ProviderComponent4 { ////////////////////////////////////////// // #docregion EvenBetterLogger @Injectable() -class EvenBetterLogger { - logs: string[] = []; +class EvenBetterLogger extends Logger { + constructor(private userService: UserService) { super(); } - constructor(private userService: UserService) { } - - log(message: string){ - message = `Message to ${this.userService.user.name}: ${message}.`; - console.log(message); - this.logs.push(message); + log(message: string) { + let name = this.userService.user.name; + super.log(`Message to ${name}: ${message}`); } } // #enddocregion EvenBetterLogger @@ -218,117 +214,69 @@ export class ProviderComponent7 { template: template, providers: [heroServiceProvider, Logger, UserService] }) -export class ProviderComponent8{ +export class ProviderComponent8 { // #docregion provider-8-ctor - constructor(heroService: HeroService){ } + constructor(heroService: HeroService) { } // #enddocregion provider-8-ctor // must be true else this component would have blown up at runtime - log = 'Hero service injected successfully'; + log = 'Hero service injected successfully via heroServiceProvider'; } ///////////////// @Component({ - selector: 'provider-9a', + selector: 'provider-9', template: template, - providers: - /* - // #docregion providers-9a-interface - // FAIL! Can't use interface as provider token - [provide(Config, {useValue: CONFIG})] - // #enddocregion providers-9a-interface - */ - // #docregion providers-9a - // Use string as provider token - [provide('app.config', {useValue: CONFIG})] - // #enddocregion providers-9a + /* + // #docregion providers-9-interface + // FAIL! Can't use interface as provider token + [provide(AppConfig, {useValue: HERO_DI_CONFIG})] + // #enddocregion providers-9-interface + */ + // #docregion providers-9 + providers: [provide(APP_CONFIG, {useValue: HERO_DI_CONFIG})] + // #enddocregion providers-9 }) -export class ProviderComponent9a { +export class ProviderComponent9 { log: string; /* - // #docregion provider-9a-ctor-interface - // FAIL! Can't inject using the interface as the parameter type - constructor(private config: Config){ } - // #enddocregion provider-9a-ctor-interface - */ - - // #docregion provider-9a-ctor - // @Inject(token) to inject the dependency - constructor(@Inject('app.config') private config: Config){ } - // #enddocregion provider-9a-ctor - - ngOnInit() { - this.log = '"app.config" Application title is ' + this.config.title; - } -} - -@Component({ - selector: 'provider-9b', - template: template, - // #docregion providers-9b - providers: [provide(APP_CONFIG, {useValue: CONFIG})] - // #enddocregion providers-9b -}) -export class ProviderComponent9b { - log: string; - // #docregion provider-9b-ctor - constructor(@Inject(APP_CONFIG) private config: Config){ } - // #enddocregion provider-9b-ctor + // #docregion provider-9-ctor-interface + // FAIL! Can't inject using the interface as the parameter type + constructor(private config: AppConfig){ } + // #enddocregion provider-9-ctor-interface + */ + // #docregion provider-9-ctor + constructor(@Inject(APP_CONFIG) private config: AppConfig) { } + // #enddocregion provider-9-ctor ngOnInit() { this.log = 'APP_CONFIG Application title is ' + this.config.title; } } ////////////////////////////////////////// -// Normal required logger -@Component({ - selector: 'provider-10a', - template: template, - // #docregion providers-logger - providers: [Logger] - // #enddocregion providers-logger -}) -export class ProviderComponent10a { - log: string; - constructor(logger: Logger) { - logger.log('Hello from the required logger.'); - this.log = logger.logs[0]; - } -} - -// Optional logger +// Sample providers 1 to 7 illustrate a required logger dependency. +// Optional logger, can be null // #docregion import-optional import {Optional} from '@angular/core'; // #enddocregion import-optional +let some_message: string = 'Hello from the injected logger'; + @Component({ - selector: 'provider-10b', + selector: 'provider-10', template: template }) -export class ProviderComponent10b { - // #docregion provider-10-ctor +export class ProviderComponent10 { log: string; - constructor(@Optional() private logger: Logger) { } + // #docregion provider-10-ctor + constructor(@Optional() private logger: Logger) { + if (this.logger) + this.logger.log(some_message); + } // #enddocregion provider-10-ctor ngOnInit() { - // #docregion provider-10-logger - // No logger? Make one! - if (!this.logger) { - this.logger = { - log: (msg: string) => this.logger.logs.push(msg), - logs: [] - }; - // #enddocregion provider-10-logger - this.logger.log('Optional logger was not available.'); - // #docregion provider-10-logger - } - // #enddocregion provider-10-logger - else { - this.logger.log('Hello from the injected logger.'); - this.log = this.logger.logs[0]; - } - this.log = this.logger.logs[0]; + this.log = this.logger ? this.logger.logs[0] : 'Optional logger was not available'; } } @@ -347,10 +295,8 @@ export class ProviderComponent10b {
-
-
-
-
+
+
`, directives: [ ProviderComponent1, @@ -363,10 +309,8 @@ export class ProviderComponent10b { ProviderComponent6b, ProviderComponent7, ProviderComponent8, - ProviderComponent9a, - ProviderComponent9b, - ProviderComponent10a, - ProviderComponent10b, + ProviderComponent9, + ProviderComponent10, ], }) export class ProvidersComponent { } diff --git a/public/docs/_examples/dependency-injection/ts/app/test.component.ts b/public/docs/_examples/dependency-injection/ts/app/test.component.ts index 48466c91d2..068cf65e7b 100644 --- a/public/docs/_examples/dependency-injection/ts/app/test.component.ts +++ b/public/docs/_examples/dependency-injection/ts/app/test.component.ts @@ -35,14 +35,14 @@ function runTests() { ////////////////////////////////// // Fake Jasmine infrastructure -var testName:string; +var testName: string; var testResults: {pass:string; message:string}; function expect(actual:any) { return { toEqual: function(expected:any){ testResults = actual === expected? - {pass:'passed', message: `${testName}`} : + {pass:'passed', message: testName} : {pass:'failed', message: `${testName}; expected ${actual} to equal ${expected}.`}; } } diff --git a/public/docs/_examples/dependency-injection/ts/app/user.service.ts b/public/docs/_examples/dependency-injection/ts/app/user.service.ts index 69ea9108b3..25e09ecaf8 100644 --- a/public/docs/_examples/dependency-injection/ts/app/user.service.ts +++ b/public/docs/_examples/dependency-injection/ts/app/user.service.ts @@ -1,23 +1,22 @@ // #docregion import {Injectable} from '@angular/core'; -@Injectable() -export class UserService { - // Todo: get the user; don't 'new' it. - private _alice = new User('Alice', true); - private _bob = new User('Bob', false); - - // initial user is Bob - user = this._bob; - - // swaps users - getNewUser() { - return this.user = this.user === this._bob ? this._alice : this._bob; - } -} - export class User { constructor( public name:string, public isAuthorized:boolean = false) { } } + +// Todo: get the user; don't 'new' it. +let alice = new User('Alice', true); +let bob = new User('Bob', false); + +@Injectable() +export class UserService { + user = bob; // initial user is Bob + + // swap users + getNewUser() { + return this.user = this.user === bob ? alice : bob; + } +} diff --git a/public/docs/dart/latest/guide/dependency-injection.jade b/public/docs/dart/latest/guide/dependency-injection.jade index ee0d41deef..b6666929c3 100644 --- a/public/docs/dart/latest/guide/dependency-injection.jade +++ b/public/docs/dart/latest/guide/dependency-injection.jade @@ -1,279 +1,138 @@ -include ../_util-fns +extends ../../../ts/latest/guide/dependency-injection.jade -+includeShared('{ts}', 'intro') +block includes + include ../_util-fns + - var _thisDot = ''; -:marked - The complete source code for the example app in this chapter is - [in GitHub](https://github.com/angular/angular.io/tree/master/public/docs/_examples/dependency-injection/dart). +block ctor-syntax + .l-sub-section + :marked + We also leveraged Dart's constructor syntax for declaring parameters and + initializing properties simultaneously. -+includeShared('{ts}', 'why-1') -+makeExample('dependency-injection/dart/lib/car/car_no_di.dart', 'car', 'lib/car/car.dart (without DI)') -+includeShared('{ts}', 'why-2') -+makeTabs( - 'dependency-injection/dart/lib/car/car.dart, dependency-injection/dart/lib/car/car_no_di.dart', - 'car-ctor, car-ctor', - 'lib/car/car.dart (excerpt with DI), lib/car/car.dart (excerpt without DI)')(format=".") -+includeShared('{ts}', 'why-3-1') -+includeShared('{ts}', 'why-3-2') -- var stylePattern = { otl: /(new Car.*$)/gm }; -+makeExample('dependency-injection/dart/lib/car/car_creations.dart', 'car-ctor-instantiation', '', stylePattern)(format=".") -+includeShared('{ts}', 'why-4') -.l-sub-section +block service-in-its-own-file + //- N/A + +block one-class-per-file-ts-tradeoffs + //- N/A + +block injectable-not-always-needed-in-ts + //- The [Angular 2 Dart Transformer](https://github.com/angular/angular/wiki/Angular-2-Dart-Transformer) + //- generates static code to replace the use of dart:mirrors. It requires that types be + //- identified as targets for static code generation. Generally this is achieved + //- by marking the class as @Injectable (though there are other mechanisms). + +block ts-any-decorator-will-do + //- N/A + +block always-include-paren :marked - The _consumer_ of `Car` has the problem. The consumer must update the car creation code to - something like this: - - var stylePattern = { otl: /(new Car.*$)/gm }; - +makeExample('dependency-injection/dart/lib/car/car_creations.dart', 'car-ctor-instantiation-with-param', '', stylePattern)(format=".") - :marked - The critical point is this: `Car` itself did not have to change. - We'll take care of the consumer's problem soon enough. -+includeShared('{ts}', 'why-6') -- var stylePattern = { otl: /(new Car.*$)/gm }; -+makeExample('dependency-injection/dart/lib/car/car_creations.dart', 'car-ctor-instantiation-with-mocks', '', stylePattern)(format=".") -+includeShared('{ts}', 'why-7') -+makeExample('dependency-injection/dart/lib/car/car_factory.dart', null, 'lib/car/car_factory.dart') -+includeShared('{ts}', 'why-8') -+makeExample('dependency-injection/dart/lib/car/car_injector.dart','injector-call')(format=".") -+includeShared('{ts}', 'why-9') - -+includeShared('{ts}', 'di-1') -+makeTabs( - `dependency-injection/dart/lib/heroes/heroes_component_1.dart, - dependency-injection/dart/lib/heroes/hero_list_component_1.dart, - dependency-injection/dart/lib/heroes/hero.dart, - dependency-injection/dart/lib/heroes/mock_heroes.dart`, - 'v1,,,', - `lib/heroes/heroes_component.dart, - lib/heroes/hero_list_component.dart, - lib/heroes/hero.dart, - lib/heroes/mock_heroes.dart`) -+includeShared('{ts}', 'di-2') -+includeShared('{ts}', 'di-3') -+makeExample('dependency-injection/dart/lib/heroes/hero_service_1.dart',null, 'lib/heroes/hero_service.dart' ) -+includeShared('{ts}', 'di-4') -.l-sub-section - :marked - We aren't even pretending this is a real service. - If we were actually getting data from a remote server, the API would have to be asynchronous, - returning a `Future`. - We'd also have to rewrite the way components consume our service. - This is important in general, but not to our current story. -+includeShared('{ts}', 'di-6') -+includeShared('{ts}', 'di-configure-injector-1') -+makeExample('dependency-injection/dart/web/main.dart', 'bootstrap', 'web/main.dart (excerpt)')(format='.') -+includeShared('{ts}', 'di-configure-injector-2') -+makeExample('dependency-injection/dart/web/main_1.dart', 'bootstrap')(format='.') -+includeShared('{ts}', 'di-configure-injector-3') -+includeShared('{ts}', 'di-register-providers-1') -+makeExample('dependency-injection/dart/lib/heroes/heroes_component_1.dart',null,'lib/heroes/heroes_component.dart') -+includeShared('{ts}', 'di-register-providers-2') -+makeExample('dependency-injection/dart/lib/heroes/heroes_component_1.dart','providers')(format='.') -+includeShared('{ts}', 'di-register-providers-3') -+includeShared('{ts}', 'di-prepare-for-injection-1') -+makeTabs( - `dependency-injection/dart/lib/heroes/hero_list_component_2.dart, - dependency-injection/dart/lib/heroes/hero_list_component_1.dart`, - null, - `lib/heroes/hero_list_component (with DI), - lib/heroes/hero_list_component (without DI)`) -.l-sub-section - :marked - ### Focus on the constructor - - Adding a parameter to the constructor isn't all that's happening here. - +makeExample('dependency-injection/dart/lib/heroes/hero_list_component_2.dart', 'ctor')(format=".") - :marked - The constructor parameter has a type: `HeroService`. - The `HeroListComponent` class is also annotated with `@Component` - (scroll up to confirm that fact). - Also recall that the parent component (`HeroesComponent`) - has `providers` information for `HeroService`. - - The constructor parameter type, the `@Component` annotation, - and the parent's `providers` information combine to tell the - Angular injector to inject an instance of - `HeroService` whenever it creates a new `HeroListComponent`. -+includeShared('{ts}', 'di-create-injector-implicitly-1') -+makeExample('dependency-injection/dart/lib/car/car_injector.dart','injector-create-and-call')(format=".") -+includeShared('{ts}', 'di-create-injector-implicitly-2') -+includeShared('{ts}', 'di-singleton-services') - -// Skip the testing section, for now. -// includeShared('{ts}', 'di-testing-component-1') -// includeShared('{ts}', 'di-testing-component-2') - -+includeShared('{ts}', 'di-service-service-1') -+makeTabs( - `dependency-injection/dart/lib/heroes/hero_service_2.dart, - dependency-injection/dart/lib/heroes/hero_service_1.dart`, - null, - `lib/heroes/hero_service (v.2), - lib/heroes/hero_service (v.1)`) -+includeShared('{ts}', 'di-service-service-2') -+includeShared('{ts}', 'di-injectable-1') -:marked - Forgetting the `@Injectable()` can cause a runtime error: -code-example(format, language="html"). - Cannot find reflection information on <Type> -+includeShared('{ts}', 'di-injectable-2') -.callout.is-critical - header Always include the parentheses - :marked - Always use `@Injectable()`, not just `@Injectable`. + Always write `@Injectable()`, not just `@Injectable`. A metadata annotation must be either a reference to a compile-time constant variable or a call to a constant constructor such as `Injectable()`. + If we forget the parentheses, the analyzer will complain: "Annotation creation must have arguments". If we try to run the app anyway, it won't work, and the console will say "expression must be a compile-time constant". -+includeShared('{ts}', 'logger-service-1') -+makeExample( - 'dependency-injection/dart/lib/logger_service.dart',null, 'lib/logger_service') -.l-sub-section + +block real-logger + .l-sub-section + :marked + A real implementation would probably use the + [logging package](https://pub.dartlang.org/packages/logging). + +block optional-logger + //- TBC. + +block provider-function-etc + //- N/A + +block provider-ctor-args + - var _secondParam = 'named parameter, such as useClass' :marked - ### Implementing a logger + We supply two arguments (or more) to the `Provider` constructor. - Our examples use a simple logger. - A real implementation would probably use the - [logging package](https://pub.dartlang.org/packages/logging). -:marked - We're likely to need the same logger service everywhere in our application, - so we put it in the `lib/` folder, and - we register it in the `providers` array of the metadata for our application root component, `AppComponent`. -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-logger', 'lib/app_component.dart (excerpt)') -+includeShared('{ts}', 'logger-service-3') -+includeShared('{ts}', 'logger-service-4') -+includeShared('{ts}', 'logger-service-5') -+makeExample('dependency-injection/dart/lib/providers_component.dart','provider-10-ctor')(format='.') -+includeShared('{ts}', 'logger-service-6') -+makeExample('dependency-injection/dart/lib/providers_component.dart','provider-10-logger')(format='.') -+includeShared('{ts}', 'logger-service-7') +block dart-diff-const-metadata + .callout.is-helpful + header Dart difference: Constants in metadata + :marked + In Dart, the value of a metadata annotation must be a compile-time constant. + For that reason, we can't call functions to get values + to use within an annotation. + Instead, we use constant literals or constant constructors. + For example, a TypeScript program might use the + function call `provide(Logger, {useClass: BetterLogger})`, + which is equivalent to the TypeScript code + `new Provider(Logger, {useClass: BetterLogger})`. + A Dart annotation would instead use the constant value `const Provider(Logger, useClass: BetterLogger)`. -+includeShared('{ts}', 'providers-1') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-logger') -+includeShared('{ts}', 'providers-2') -+includeShared('{ts}', 'providers-provide-1') -:marked - ### The *Provider* class -+includeShared('{ts}', 'providers-provide-1-1') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-1') -+includeShared('{ts}', 'providers-provide-2') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-2') -// includeShared('{ts}', 'providers-provide-3') -// includeShared('{ts}', 'providers-provide-4-1') -// Don't discuss provide function. -:marked - We supply two arguments (or more) to the `Provider` constructor. -+includeShared('{ts}', 'providers-provide-4-2') -:marked - The second is a named parameter, such as `useClass`, - that we can think of as a *recipe* for creating the dependency value. - There are many ways to create dependency values... and many ways to write a recipe. -+includeShared('{ts}', 'providers-alternative-1') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-4') -.callout.is-helpful - header Dart difference: Constants in metadata +block dart-diff-const-metadata-ctor + .callout.is-helpful + header Dart difference: Constants in metadata + :marked + Because Dart annotations must be compile-time constants, + `useValue` is often used with string or list literals. + However, `useValue` works with any constant object. + + To create a class that can provide constant objects, + ensure all its instance variables are `final`, + and give it a `const` constructor. + + Create a constant instance of the class by using `const` instead of `new`. + +// - var stylePattern = { otl: /(useValue.*\))/gm }; +// +makeExample('dependency-injection/dart/lib/providers_component.dart','providers-9','', stylePattern)(format='.') + +block non-class-dep-eg + span string, list, map, or maybe a function. + +block config-obj-maps + | . They can be + | Map + | literals + +block what-should-we-use-as-token :marked - In Dart, the value of a metadata annotation must be a compile-time constant. - For that reason, we can't call functions to get values - to use within an annotation. - Instead, we use constant literals or constant constructors. - For example, a TypeScript program might use the - function call `provide(Logger, {useClass: BetterLogger})`, - which is equivalent to the TypeScript code - `new Provider(Logger, {useClass: BetterLogger})`. - A Dart annotation would instead use the constant value `const Provider(Logger, useClass: BetterLogger)`. -+includeShared('{ts}', 'providers-alternative-2') -+makeExample('dependency-injection/dart/lib/providers_component.dart','EvenBetterLogger') -+includeShared('{ts}', 'providers-alternative-3') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-5')(format=".") -+includeShared('{ts}', 'providers-aliased-1') -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-6a')(format=".") -+includeShared('{ts}', 'providers-aliased-2') -- var stylePattern = { otl: /(useExisting.*\))/gm }; -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-6b','', stylePattern)(format=".") + But what should we use as the token? + While we _could_ use **[Map][]**, we _should not_ because (like + `String`) `Map` is too general. Our app might depend on several maps, each + for a different purpose. -+includeShared('{ts}', 'providers-value-1') -:marked - We can provide objects directly, - instead of asking the injector to create an instance of a class, - by specifying a `useValue` parameter to `Provider`. + [Map]: https://api.dartlang.org/stable/dart-core/Map-class.html - Because Dart annotations must be compile-time constants, - `useValue` is often used with string or list literals. - However, `useValue` works with any constant object. + .callout.is-helpful + header Dart difference: Interfaces are valid tokens + :marked + In TypeScript, interfaces don't work as provider tokens. + Dart doesn't have this limitation; + every class implicitly defines an interface, + so interface names are just class names. + `Map` is a *valid* token even though it's the name of an abstract class; + it's just *unsuitable* as a token because it's too general. - To create a class that can provide constant objects, - make sure all its instance variables are `final`, - and give it a `const` constructor: - -+makeExample('dependency-injection/dart/lib/app_config.dart','const-class','lib/app_config.dart (excerpt)')(format='.') - -:marked - Create a constant instance of the class by using `const` instead of `new`: - -+makeExample('dependency-injection/dart/lib/app_config.dart','const-object','lib/app_config.dart (excerpt)')(format='.') - -:marked - Then specify the object using the `useValue` argument to `Provider`: - -- var stylePattern = { otl: /(useValue.*\))/gm }; -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-9','', stylePattern)(format='.') - -:marked - See more `useValue` examples in the - [Non-class dependencies](#non-class-dependencies) and - [OpaqueToken](#opaquetoken) sections. - -+includeShared('{ts}', 'providers-factory-1') -+makeExample('dependency-injection/dart/lib/heroes/hero_service.dart','internals', 'lib/heroes/hero_service.dart (excerpt)')(format='.') -+includeShared('{ts}', 'providers-factory-2') -+makeExample('dependency-injection/dart/lib/heroes/hero_service_provider.dart','factory', 'lib/heroes/hero_service_provider.dart (excerpt)')(format='.') -+includeShared('{ts}', 'providers-factory-3') -+makeExample('dependency-injection/dart/lib/heroes/hero_service_provider.dart','provider', 'lib/heroes/hero_service_provider.dart (excerpt)')(format='.') -+includeShared('{ts}', 'providers-factory-4') -+includeShared('{ts}', 'providers-factory-5') -- var stylePattern = { otl: /(providers.*),$/gm }; -+makeTabs( - `dependency-injection/dart/lib/heroes/heroes_component.dart, - dependency-injection/dart/lib/heroes/heroes_component_1.dart`, - null, - `lib/heroes/heroes_component (v.3), - lib/heroes/heroes_component (v.2)`, - stylePattern) -+includeShared('{ts}', 'tokens-1') -+makeExample('dependency-injection/dart/lib/injector_component.dart','get-hero-service')(format='.') -+includeShared('{ts}', 'tokens-2') -// [PENDING: How about a better name than ProviderComponent8?] -+makeExample('dependency-injection/dart/lib/providers_component.dart','provider-8-ctor')(format=".") -+includeShared('{ts}', 'tokens-3') -.callout.is-helpful - header Dart difference: Interfaces are valid tokens +block dart-map-alternative :marked - In TypeScript, interfaces don't work as provider tokens. - Dart doesn't have this problem; - every class implicitly defines an interface, - so interface names are just class names. -+includeShared('{ts}', 'tokens-non-class-deps-1') -:marked - We know we can register an object with a [value provider](#value-provider). - But what do we use for the token? -+includeShared('{ts}', 'tokens-opaque-1') -+makeExample('dependency-injection/dart/lib/providers_component.dart','opaque-token')(format='.') -+includeShared('{ts}', 'tokens-opaque-2') -+makeExample('dependency-injection/dart/lib/providers_component.dart','use-opaque-token')(format=".") -:marked - Here's an example of providing configuration information - for an injected class. First define the class: -+makeExample('dependency-injection/dart/lib/providers_component.dart','configurable-logger')(format=".") -:marked - Then inject that class and its configuration information: -+makeExample('dependency-injection/dart/lib/providers_component.dart','providers-7')(format=".") + As an alternative to using a configuration `Map`, we can define + a custom configuration class: + +makeExample('dependency-injection/ts/app/app.config.ts','config-alt','app/app-config.ts (alternative config)')(format='.') -+includeShared('{ts}', 'summary') + :marked + Defining a configuration class has a few benefits. One key benefit + is strong static checking: we'll be warned early if we misspell a property + name or assign it a value of the wrong type. + The Dart [cascade notation][cascade] (`..`) provides a convenient means of initializing + a configuration object. -+includeShared('{ts}', 'appendix-explicit-injector-1') -+makeExample('dependency-injection/dart/lib/injector_component.dart', 'injector', 'lib/injector_component.dart') -+includeShared('{ts}', 'appendix-explicit-injector-2') + If we use cascades, the configuration object can't be declared `const` and + we can't use a [value provider](#value-provider). + A solution is to use a [factory provider](#factory-provider). + We illustrate this next. We also show how to provide and inject the + configuration object in our top-level `AppComponent`: + + [cascade]: https://www.dartlang.org/docs/dart-up-and-running/ch02.html#cascade + + +makeExcerpt('lib/app_component.dart','providers') + +makeExcerpt('lib/app_component.dart','ctor') diff --git a/public/docs/ts/latest/guide/dependency-injection.jade b/public/docs/ts/latest/guide/dependency-injection.jade index 3fad879b1f..5038d1e64b 100644 --- a/public/docs/ts/latest/guide/dependency-injection.jade +++ b/public/docs/ts/latest/guide/dependency-injection.jade @@ -1,6 +1,7 @@ -include ../_util-fns +block includes + include ../_util-fns + - var _thisDot = 'this.'; -// #docregion intro :marked **Dependency injection** is an important application design pattern. Angular has its own dependency injection framework, and @@ -9,34 +10,35 @@ include ../_util-fns In this chapter we'll learn what DI is and why we want it. Then we'll learn [how to use it](#angular-di) in an Angular app. -// #enddocregion intro -:marked - [Run the live example](/resources/live-examples/dependency-injection/ts/plnkr.html) -// #docregion why-1 - -.l-main-section + + - [Why dependency injection?](#why-dependency-injection) + - [Angular dependency injection](#angular-dependency-injection) + - [Injector providers](#injector-providers) + - [Dependency injection tokens](#dependency-injection-tokens) + - [Summary](#summary) + +p Run the #[+liveExampleLink2()]. + +.l-main-section#why-di :marked ## Why dependency injection? Let's start with the following code. -// #enddocregion why-1 + +makeExample('dependency-injection/ts/app/car/car-no-di.ts', 'car', 'app/car/car.ts (without DI)') -// #docregion why-2 -- var lang = current.path[1] -- var prefix = lang == 'dart' ? '' : 'this.' + :marked Our `Car` creates everything it needs inside its constructor. What's the problem? - The problem is that our `Car` class is brittle, inflexible, and hard to test. Our `Car` needs an engine and tires. Instead of asking for them, - the `Car` constructor creates its own copies by "new-ing" them from - the very specific classes, `Engine` and `Tires`. + the `Car` constructor instantiates its own copies from + the very specific classes `Engine` and `Tires`. What if the `Engine` class evolves and its constructor requires a parameter? Our `Car` is broken and stays broken until we rewrite it along the lines of - `#{prefix}engine = new Engine(theNewParameter)`. + `#{_thisDot}engine = new Engine(theNewParameter)`. We didn't care about `Engine` constructor parameters when we first wrote `Car`. We don't really care about them now. But we'll *have* to start caring because @@ -67,31 +69,30 @@ include ../_util-fns How can we make `Car` more robust, flexible, and testable? + That's super easy. We change our `Car` constructor to a version with DI: - -// #enddocregion why-2 +makeTabs( 'dependency-injection/ts/app/car/car.ts, dependency-injection/ts/app/car/car-no-di.ts', 'car-ctor, car-ctor', 'app/car/car.ts (excerpt with DI), app/car/car.ts (excerpt without DI)')(format=".") -// #docregion why-3-1 + :marked See what happened? We moved the definition of the dependencies to the constructor. Our `Car` class no longer creates an engine or tires. It just consumes them. -// #enddocregion why-3-1 -// TypeScript only -.l-sub-section - :marked - We also leverage TypeScript's constructor syntax for declaring parameters and properties simultaneously. -// #docregion why-3-2 + +block ctor-syntax + .l-sub-section + :marked + We also leveraged TypeScript's constructor syntax for declaring + parameters and properties simultaneously. + :marked Now we create a car by passing the engine and tires to the constructor. -// #enddocregion why-3-2 -- var stylePattern = { otl: /(new Car.*$)/gm }; -+makeExample('dependency-injection/ts/app/car/car-creations.ts', 'car-ctor-instantiation', '', stylePattern)(format=".") -// #docregion why-4 + ++makeExample('dependency-injection/ts/app/car/car-creations.ts', 'car-ctor-instantiation', '')(format=".") + :marked How cool is that? The definition of the engine and tire dependencies are @@ -100,8 +101,7 @@ include ../_util-fns conform to the general API requirements of an engine or tires. If someone extends the `Engine` class, that is not `Car`'s problem. -// #enddocregion why-4 -// Must copy the following, due to indented +make. + .l-sub-section :marked The _consumer_ of `Car` has the problem. The consumer must update the car creation code to @@ -113,16 +113,16 @@ include ../_util-fns :marked The critical point is this: `Car` itself did not have to change. We'll take care of the consumer's problem soon enough. -// #docregion why-6 + :marked The `Car` class is much easier to test because we are in complete control of its dependencies. We can pass mocks to the constructor that do exactly what we want them to do during each test: -// #enddocregion why-6 + - var stylePattern = { otl: /(new Car.*$)/gm }; +makeExample('dependency-injection/ts/app/car/car-creations.ts', 'car-ctor-instantiation-with-mocks', '', stylePattern)(format=".") -// #docregion why-7 + :marked **We just learned what dependency injection is**. @@ -136,9 +136,9 @@ include ../_util-fns We need something that takes care of assembling these parts for us. We could write a giant class to do that: -// #enddocregion why-7 + +makeExample('dependency-injection/ts/app/car/car-factory.ts', null, 'app/car/car-factory.ts') -// #docregion why-8 + :marked It's not so bad now with only three creation methods. But maintaining it will be hairy as the application grows. @@ -153,9 +153,9 @@ include ../_util-fns We register some classes with this injector, and it figures out how to create them. When we need a `Car`, we simply ask the injector to get it for us and we're good to go. -// #enddocregion why-8 + +makeExample('dependency-injection/ts/app/car/car-injector.ts','injector-call')(format=".") -// #docregion why-9 + :marked Everyone wins. The `Car` knows nothing about creating an `Engine` or `Tires`. The consumer knows nothing about creating a `Car`. @@ -166,10 +166,8 @@ include ../_util-fns Now that we know what dependency injection is and appreciate its benefits, let's see how it is implemented in Angular. -// #enddocregion why-9 -// #docregion di-1 - -.l-main-section + +.l-main-section#angular-di :marked ## Angular dependency injection @@ -181,7 +179,7 @@ include ../_util-fns We'll begin with a simplified version of the `HeroesComponent` that we built in the [The Tour of Heroes](../tutorial/). -// #enddocregion di-1 + +makeTabs( `dependency-injection/ts/app/heroes/heroes.component.1.ts, dependency-injection/ts/app/heroes/hero-list.component.1.ts, @@ -192,14 +190,13 @@ include ../_util-fns app/heroes/hero-list.component.ts, app/heroes/hero.ts, app/heroes/mock-heroes.ts`) -// #docregion di-2 + :marked The `HeroesComponent` is the root component of the *Heroes* feature area. It governs all the child components of this area. Our stripped down version has only one child, `HeroListComponent`, which displays a list of heroes. -// #enddocregion di-2 -// #docregion di-3 + :marked Right now `HeroListComponent` gets heroes from `HEROES`, an in-memory collection defined in another file. @@ -209,51 +206,57 @@ include ../_util-fns fix every other use of the `HEROES` mock data. Let's make a service that hides how we get hero data. -// #enddocregion di-3 -// Unnecessary for Dart .l-sub-section :marked - Write this service in its own file. See [this note](#forward-ref) to understand why. + Given that the service is a + [separate concern](https://en.wikipedia.org/wiki/Separation_of_concerns), + we suggest that you + write the service code in its own file. + +ifDocsFor('ts') + :marked + See [this note](#one-class-per-file) for details. + +makeExample('dependency-injection/ts/app/heroes/hero.service.1.ts',null, 'app/heroes/hero.service.ts' ) -// #docregion di-4 + :marked Our `HeroService` exposes a `getHeroes` method that returns the same mock data as before, but none of its consumers need to know that. -// #enddocregion di-4 -// #docregion di-5 +.l-sub-section + :marked + Notice the `@Injectable()` #{_decorator} above the service class. + We'll discuss its purpose [shortly](#injectable). + +- var _perhaps = _docsFor == 'dart' ? '' : 'perhaps'; .l-sub-section :marked We aren't even pretending this is a real service. - If we were actually getting data from a remote server, the API would have to be asynchronous, - perhaps returning - [ES2015 promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise). + If we were actually getting data from a remote server, the API would have to be + asynchronous, #{_perhaps} returning a !{_PromiseLinked}. We'd also have to rewrite the way components consume our service. This is important in general, but not to our current story. -// #enddocregion di-5 -// #docregion di-6 + :marked A service is nothing more than a class in Angular 2. It remains nothing more than a class until we register it with an Angular injector. -// #enddocregion di-6 -// #docregion di-configure-injector-1 + +#bootstrap :marked ### Configuring the injector - We don't have to create an Angular injector. Angular creates an application-wide injector for us during the bootstrap process. -// #enddocregion di-configure-injector-1 + +makeExample('dependency-injection/ts/app/main.ts', 'bootstrap', 'app/main.ts (excerpt)')(format='.') -// #docregion di-configure-injector-2 + :marked We do have to configure the injector by registering the **providers** that create the services our application requires. We'll explain what [providers](#providers) are later in this chapter. Before we do, let's see an example of provider registration during bootstrapping: -// #enddocregion di-configure-injector-2 -+makeExample('dependency-injection/ts/app/main.1.ts', 'bootstrap')(format='.') -// #docregion di-configure-injector-3 + ++makeExample('dependency-injection/ts/app/main.1.ts', 'bootstrap-discouraged')(format='.') + :marked The injector now knows about our `HeroService`. An instance of our `HeroService` will be available for injection across our entire application. @@ -266,81 +269,78 @@ include ../_util-fns The preferred approach is to register application providers in application components. Because the `HeroService` is used within the *Heroes* feature area — and nowhere else — the ideal place to register it is in the top-level `HeroesComponent`. -// #enddocregion di-configure-injector-3 -// #docregion di-register-providers-1 + :marked ### Registering providers in a component Here's a revised `HeroesComponent` that registers the `HeroService`. -// #enddocregion di-register-providers-1 -+makeExample('dependency-injection/ts/app/heroes/heroes.component.1.ts',null,'app/heroes/heroes.component.ts') -// #docregion di-register-providers-2 -:marked - Look closely at the `providers` part of the `@Component` metadata: -// #enddocregion di-register-providers-2 -+makeExample('dependency-injection/ts/app/heroes/heroes.component.1.ts','providers')(format='.') -// #docregion di-register-providers-3 + +- var stylePattern = { otl: /(providers:.*),/ }; ++makeExample('dependency-injection/ts/app/heroes/heroes.component.1.ts', 'full','app/heroes/heroes.component.ts', stylePattern)(format='.') + :marked + Look closely at the `providers` part of the `@Component` metadata. An instance of the `HeroService` is now available for injection in this `HeroesComponent` and all of its child components. The `HeroesComponent` itself doesn't happen to need the `HeroService`. But its child `HeroListComponent` does, so we head there next. -// #enddocregion di-register-providers-3 -// #docregion di-prepare-for-injection-1 + :marked ### Preparing the HeroListComponent for injection The `HeroListComponent` should get heroes from the injected `HeroService`. - Per the dependency injection pattern, the component must ask for the service in its constructor, [as we explained - earlier](#ctor-injection). + Per the dependency injection pattern, the component must ask for the service in its + constructor, [as we explained earlier](#ctor-injection). It's a small change: -// #enddocregion di-prepare-for-injection-1 + +makeTabs( `dependency-injection/ts/app/heroes/hero-list.component.2.ts, dependency-injection/ts/app/heroes/hero-list.component.1.ts`, null, `app/heroes/hero-list.component (with DI), app/heroes/hero-list.component (without DI)`) -// Must copy the following, due to indented +make. + .l-sub-section :marked - ### Focus on the constructor + #### Focus on the constructor Adding a parameter to the constructor isn't all that's happening here. +makeExample('dependency-injection/ts/app/heroes/hero-list.component.2.ts', 'ctor')(format=".") - // TypeScript only :marked - We're writing in TypeScript and have followed the parameter name with a type annotation, `:HeroService`. - The class is also decorated with the `@Component` decorator (scroll up to confirm that fact). + Note that the constructor parameter has the type `HeroService`, and that + the `HeroListComponent` class has an `@Component` #{_decorator} + (scroll up to confirm that fact). + Also recall that the parent component (`HeroesComponent`) + has `providers` information for `HeroService`. - When the TypeScript compiler evaluates this class, it sees the `@Component` decorator and adds class metadata - into the generated JavaScript code. Within that metadata lurks the information that - associates the `heroService` parameter with the `HeroService` class. + The constructor parameter type, the `@Component` #{_decorator}, + and the parent's `providers` information combine to tell the + Angular injector to inject an instance of + `HeroService` whenever it creates a new `HeroListComponent`. - That's how the Angular injector knows to inject an instance of the `HeroService` when it - creates a new `HeroListComponent`. -// #docregion di-create-injector-implicitly-1 +#di-metadata :marked - - ### Creating the injector (implicitly) - When we introduced the idea of an injector above, we showed how to create - an injector and use it to create a new `Car`. -// #enddocregion di-create-injector-implicitly-1 + ### Implicit injector creation + + When we introduced the idea of an injector above, we showed how to + use it to create a new `Car`. Here we also show how such an injector + would be explicitly created: + +makeExample('dependency-injection/ts/app/car/car-injector.ts','injector-create-and-call')(format=".") -// #docregion di-create-injector-implicitly-2 + :marked We won't find code like that in the Tour of Heroes or any of our other samples. - We *could* write [code with an explicit injector](#explicit-injector) if we *had* to, but we rarely do. + We *could* write code that [explicitly creates an injector](#explicit-injector) if we *had* to, but we rarely do. Angular takes care of creating and calling injectors when it creates components for us — whether through HTML markup, as in ``, or after navigating to a component with the [router](./router.html). If we let Angular do its job, we'll enjoy the benefits of automated dependency injection. -// #enddocregion di-create-injector-implicitly-2 -// #docregion di-singleton-services + :marked ### Singleton services + Dependencies are singletons within the scope of an injector. In our example, a single `HeroService` instance is shared among the `HeroesComponent` and its `HeroListComponent` children. @@ -348,27 +348,25 @@ include ../_util-fns However, Angular DI is an hierarchical injection system, which means that nested injectors can create their own service instances. Learn more about that in the [Hierarchical Injectors](./hierarchical-dependency-injection.html) chapter. -// #enddocregion di-singleton-services -// Skip this for Dart, for now -// #docregion di-testing-component-1 :marked ### Testing the component + We emphasized earlier that designing a class for dependency injection makes the class easier to test. Listing dependencies as constructor parameters may be all we need to test application parts effectively. For example, we can create a new `HeroListComponent` with a mock service that we can manipulate under test: -// #enddocregion di-testing-component-1 + +makeExample('dependency-injection/ts/app/test.component.ts', 'spec')(format='.') -// #docregion di-testing-component-2 + .l-sub-section :marked Learn more in [Testing](../testing/index.html). -// #enddocregion di-testing-component-2 -// #docregion di-service-service-1 + :marked ### When the service needs a service + Our `HeroService` is very simple. It doesn't have any dependencies of its own. @@ -377,144 +375,110 @@ include ../_util-fns adding a constructor that takes a `Logger` parameter. Here is the revision compared to the original. -// #enddocregion di-service-service-1 + +makeTabs( `dependency-injection/ts/app/heroes/hero.service.2.ts, dependency-injection/ts/app/heroes/hero.service.1.ts`, null, - `app/heroes/hero.service (v.2), - app/heroes/hero.service (v.1)`) -// #docregion di-service-service-2 + `app/heroes/hero.service (v2), + app/heroes/hero.service (v1)`) + :marked - The constructor now asks for an injected instance of a `Logger` and stores it in a private property called `logger`. + The constructor now asks for an injected instance of a `Logger` and stores it in a private property called `#{_priv}logger`. We call that property within our `getHeroes` method when anyone asks for heroes. -// #enddocregion di-service-service-2 -// #docregion di-injectable-1 -- var lang = current.path[1] -- var decoration = lang == 'dart' ? 'annotation' : 'decoration' -- var tsmetadata = lang == 'ts' ? 'As we mentioned earlier, TypeScript only generates metadata for classes that have a decorator.' : '' + +//- FIXME refer to Dart API when that page becomes available. +- var injMetaUrl = 'https://angular.io/docs/ts/latest/api/core/index/InjectableMetadata-class.html'; +h3#injectable Why @Injectable()? :marked - - ### Why @Injectable? - Notice the `@Injectable()` #{decoration} above the service class. - We haven't seen `@Injectable()` before. - As it happens, we could have added it to our first version of `HeroService`. - We didn't bother because we didn't need it then. + **@Injectable()** marks a class as available to an + injector for instantiation. Generally speaking, an injector will report an + error when trying to instantiate a class that is not marked as + `@Injectable()`. - We need it now... now that our service has an injected dependency. - We need it because Angular requires constructor parameter metadata in order to inject a `Logger`. !{tsmetadata} -// #enddocregion di-injectable-1 +block injectable-not-always-needed-in-ts + .l-sub-section + :marked + As it happens, we could have omitted `@Injectable()` from our first + version of `HeroService` because it had no injected parameters. + But we must have it now that our service has an injected dependency. + We need it because Angular requires constructor parameter metadata + in order to inject a `Logger`. -// #docregion di-injectable-2 -- var lang = current.path[1] -- var a_decorator = lang == 'dart' ? 'an annotation' : 'a decorator' -- var decorated = lang == 'dart' ? 'annotated' : 'decorated' -- var any_decorator = lang == 'dart' ? '' : 'TypeScript generates metadata for any class with a decorator, and any decorator will do.' -.callout.is-helpful - header Suggestion: add @Injectable() to every service class - :marked - We recommend adding `@Injectable()` to every service class, even those that don't have dependencies - and, therefore, do not technically require it. Here's why: - ul(style="font-size:inherit") - li Future proofing: No need to remember @Injectable() when we add a dependency later. - li Consistency: All services follow the same rules, and we don't have to wonder why #{a_decorator} is missing. + .callout.is-helpful + header Suggestion: add @Injectable() to every service class + :marked + We recommend adding `@Injectable()` to every service class, even those that don't have dependencies + and, therefore, do not technically require it. Here's why: - :marked - Although we recommend applying `@Injectable` to all service classes, do not feel bound by it. - Some developers prefer to add it only where needed and that's a reasonable policy too. + ul(style="font-size:inherit") + li Future proofing: No need to remember @Injectable() when we add a dependency later. + li Consistency: All services follow the same rules, and we don't have to wonder why #{_a} #{_decorator} is missing. -.l-sub-section - :marked - The `HeroesComponent` has an injected dependency too. Why don't we add `@Injectable()` to the `HeroesComponent`? +:marked + Injectors are also responsible for instantiating components + like `HeroesComponent`. Why haven't we marked `HeroesComponent` as + `@Injectable()`? + + We *can* add it if we really want to. It isn't necessary because the + `HeroesComponent` is already marked with `@Component`, and this + !{_decorator} class (like `@Directive` and `@Pipe`, which we'll learn about later) + is a subtype of InjectableMetadata. It is in + fact `InjectableMetadata` #{_decorator}s that + identify a class as a target for instantiation by an injector. + +block ts-any-decorator-will-do + .l-sub-section + :marked + Injectors use a class's constructor metadata to determine dependent types as + identified by the constructor's parameter types. + TypeScript generates such metadata for any class with a decorator, and any decorator will do. + But of course, it is more meaningful to mark a class using the appropriate + InjectableMetadata #{_decorator}. - We *can* add it if we really want to. It isn't necessary because - the `HeroesComponent` is already #{decorated} with `@Component`. #{any_decorator} -// #enddocregion di-injectable-2 .callout.is-critical header Always include the parentheses - :marked - Always use `@Injectable()`, not just `@Injectable`. - Our application will fail mysteriously if we forget the parentheses. + block always-include-paren + :marked + Always write `@Injectable()`, not just `@Injectable`. + Our application will fail mysteriously if we forget the parentheses. -// #docregion logger-service-1 -.l-main-section +.l-main-section#logger-service :marked ## Creating and registering a logger service + We're injecting a logger into our `HeroService` in two steps: 1. Create the logger service. 1. Register it with the application. - The logger service implementation is no big deal. -// #enddocregion logger-service-1 -+makeExample( - 'dependency-injection/ts/app/logger.service.ts',null, 'app/logger.service') + Our logger service is quite simple: + ++makeExample('dependency-injection/ts/app/logger.service.ts', null, 'app/logger.service.ts') + +block real-logger + //- N/A -// Copied into Dart, due to different directory structure :marked We're likely to need the same logger service everywhere in our application, - so we put it at the root level of the application in the `app/` folder, and - we register it in the `providers` array of the metadata for our application root component, `AppComponent`. -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-logger', 'app/app.component.ts (excerpt)') -// #docregion logger-service-3 + so we put it in the project's `#{_appDir}` folder, and + we register it in the `providers` #{_array} of the metadata for our application root component, `AppComponent`. + ++makeExcerpt('app/providers.component.ts','providers-logger','app/app.component.ts (excerpt)') + :marked If we forget to register the logger, Angular throws an exception when it first looks for the logger: -code-example(format, language="html"). +code-example(format="nocode"). EXCEPTION: No provider for Logger! (HeroListComponent -> HeroService -> Logger) -// #enddocregion logger-service-3 -// #docregion logger-service-4 + :marked That's Angular telling us that the dependency injector couldn't find the *provider* for the logger. It needed that provider to create a `Logger` to inject into a new `HeroService`, which it needed to create and inject into a new `HeroListComponent`. - The chain of creations started with the `Logger` provider. The *provider* is the subject of our next section. + The chain of creations started with the `Logger` provider. *Providers* are the subject of our next section. - But wait! What if the logger is optional? - - ### Optional dependencies - - Our `HeroService` currently requires a `Logger`. What if we could get by without a logger? - We'd use it if we had it, ignore it if we didn't. We can do that. -// #enddocregion logger-service-4 - -// TypeScript only? -:marked - First import the `@Optional()` decorator. -+makeExample('dependency-injection/ts/app/providers.component.ts','import-optional')(format='.') - -// #docregion logger-service-5 -- var lang = current.path[1] -- var rewrite = lang == 'dart' ? 'Just rewrite' : 'Then rewrite' -- var decorator = lang == 'dart' ? 'annotation' : 'decorator' -:marked - #{rewrite} the constructor with the `@Optional()` #{decorator} preceding the private `logger` parameter. - That tells the injector that `logger` is optional. -// #enddocregion logger-service-5 -+makeExample('dependency-injection/ts/app/providers.component.ts','provider-10-ctor')(format='.') -// #docregion logger-service-6 -:marked - Be prepared for a null logger. If we don't register one somewhere up the line, - the injector will inject `null`. We have a method that logs. - What can we do to avoid a null reference exception? - - We could substitute a *do-nothing* logger stub so that calling methods continue to work: -// #enddocregion logger-service-6 -+makeExample('dependency-injection/ts/app/providers.component.ts','provider-10-logger')(format='.') -// #docregion logger-service-7 -:marked - Obviously we'd take a more sophisticated approach if the logger were optional - in multiple locations. - - But enough about optional loggers. In our sample application, the `Logger` is required. - We must register a `Logger` with the application injector using *providers*, - as we learn in the next section. -// #enddocregion logger-service-7 - -// #docregion providers-1 -:marked - -.l-main-section +.l-main-section#providers :marked ## Injector providers @@ -524,20 +488,16 @@ code-example(format, language="html"). We must register a service *provider* with the injector, or it won't know how to create the service. - Earlier we registered the `Logger` service in the `providers` array of the metadata for the `AppComponent` like this: -// #enddocregion providers-1 -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-logger') -// #docregion providers-2 -- var lang = current.path[1] -- var implements = lang == 'dart' ? 'implements' : 'looks and behaves like a ' -- var objectlike = lang == 'dart' ? '' : 'an object that behaves like ' -- var loggerlike = lang == 'dart' ? '' : 'We could provide a logger-like object. ' -:marked - The `providers` array appears to hold a service class. - In reality it holds an instance of the [Provider](../api/core/Provider-class.html) class that can create that service. + Earlier we registered the `Logger` service in the `providers` #{_array} of the metadata for the `AppComponent` like this: ++makeExample('dependency-injection/ts/app/providers.component.ts','providers-logger') + +- var implements = _docsFor == 'dart' ? 'implements' : 'looks and behaves like a ' +- var objectlike = _docsFor == 'dart' ? '' : 'an object that behaves like ' +- var loggerlike = _docsFor == 'dart' ? '' : 'We could provide a logger-like object. ' +:marked There are many ways to *provide* something that #{implements} `Logger`. - The `Logger` class itself is an obvious and natural provider — it has the right shape and it's designed to be created. + The `Logger` class itself is an obvious and natural provider. But it's not the only way. We can configure the injector with alternative providers that can deliver #{objectlike} a `Logger`. @@ -546,80 +506,79 @@ code-example(format, language="html"). Any of these approaches might be a good choice under the right circumstances. What matters is that the injector has a provider to go to when it needs a `Logger`. -// #enddocregion providers-2 -// #docregion providers-provide-1 -:marked - -// #enddocregion providers-provide-1 -// Don't mention provide function in Dart +//- Dart limitation: the provide function isn't const so it cannot be used in an annotation. +- var __andProvideFn = _docsFor == 'dart' ? '' : 'and provide function'; +#provide :marked - ### The *Provider* class and *provide* function -// #docregion providers-provide-1-1 + ### The *Provider* class !{__andProvideFn} + :marked - We wrote the `providers` array like this: -// #enddocregion providers-provide-1-1 + We wrote the `providers` #{_array} like this: + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-1') -// #docregion providers-provide-2 + :marked This is actually a short-hand expression for a provider registration that creates a new instance of the [Provider](../api/core/Provider-class.html) class. -// #enddocregion providers-provide-2 + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-2') -// #docregion providers-provide-3 -// Skip for Dart, where the provide() function won't pass type checking. -:marked - The [provide](../api/core/provide-function.html) function is the typical way to create a `Provider`: -// #enddocregion providers-provide-3 -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-3') -// #docregion providers-provide-4-1 -// Modified for Dart. -:marked - Or we can declare a provider in an _object literal_ and skip the `provide` function. -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-3a') +block provider-function-etc + :marked + The [provide](../api/core/provide-function.html) function is the typical way + to create a `Provider`: -:marked - Pick the syntax that you prefer. They all do the same thing. - - In each syntax, we supply two types of values. -// #enddocregion providers-provide-4-1 -// #docregion providers-provide-4-2 + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-3') + + :marked + Or we can declare a provider in an _object literal_ and skip the `provide` function. + + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-3a') + + :marked + Pick the syntax that you prefer. They all do the same thing. + +block provider-ctor-args + - var _secondParam = 'provider definition object'; + :marked + In each syntax, we supply two types of values. + +//- var _secondParam = _docsFor == 'dart' ? 'named parameter, such as useClass' : 'provider definition object'; :marked The first is the [token](#token) that serves as the key for both locating a dependency value and registering the provider. -// #enddocregion providers-provide-4-2 -// Dart is different here (uses an optional parameter) + The second is a !{_secondParam}, + which we can think of as a *recipe* for creating the dependency value. + There are many ways to create dependency values ... and many ways to write a recipe. + +#class-provider :marked - The second is a provider definition object, - which we can think of as a *recipe* for creating the dependency value. - There are many ways to create dependency values... and many ways to write a recipe. - -// #docregion providers-alternative-1 -:marked - ### Alternative class providers Occasionally we'll ask a different class to provide the service. The following code tells the injector to return a `BetterLogger` when something asks for the `Logger`. -// #enddocregion providers-alternative-1 + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-4') -// #docregion providers-alternative-2 + +block dart-diff-const-metadata + //- N/A + :marked ### Class provider with dependencies Maybe an `EvenBetterLogger` could display the user name in the log message. This logger gets the user from the injected `UserService`, which happens also to be injected at the application level. -// #enddocregion providers-alternative-2 + +makeExample('dependency-injection/ts/app/providers.component.ts','EvenBetterLogger')(format='.') -// #docregion providers-alternative-3 + :marked Configure it like we did `BetterLogger`. -// #enddocregion providers-alternative-3 + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-5')(format=".") -// #docregion providers-aliased-1 + :marked ### Aliased class providers @@ -636,30 +595,40 @@ code-example(format, language="html"). We certainly do not want two different `NewLogger` instances in our app. Unfortunately, that's what we get if we try to alias `OldLogger` to `NewLogger` with `useClass`. -// #enddocregion providers-aliased-1 + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-6a')(format=".") -// #docregion providers-aliased-2 + :marked - The solution: Alias with the `useExisting` option. -// #enddocregion providers-aliased-2 -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-6b')(format=".") -// #docregion providers-value-1 - + The solution: alias with the `useExisting` option. + +- var stylePattern = { otl: /(useExisting: \w*)/gm }; ++makeExample('dependency-injection/ts/app/providers.component.ts','providers-6b', '', stylePattern)(format=".") + +#value-provider :marked ### Value providers -// #enddocregion providers-value-1 -// Typescript only :marked Sometimes it's easier to provide a ready-made object rather than ask the injector to create it from a class. + +block dart-diff-const-metadata-ctor + //- N/A + +makeExample('dependency-injection/ts/app/providers.component.ts','silent-logger')(format=".") + :marked Then we register a provider with the `useValue` option, which makes this object play the logger role. -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-7')(format=".") -// #docregion providers-factory-1 - +- var stylePattern = { otl: /(useValue: \w*)/gm }; ++makeExample('dependency-injection/ts/app/providers.component.ts','providers-7', '', stylePattern)(format=".") + +:marked + See more `useValue` examples in the + [Non-class dependencies](#non-class-dependencies) and + [OpaqueToken](#opaquetoken) sections. + +#factory-provider :marked ### Factory providers @@ -672,7 +641,7 @@ code-example(format, language="html"). This situation calls for a **factory provider**. Let's illustrate by adding a new business requirement: - The HeroService must hide *secret* heroes from normal users. + the HeroService must hide *secret* heroes from normal users. Only authorized users should see secret heroes. Like the `EvenBetterLogger`, the `HeroService` needs a fact about the user. @@ -683,61 +652,61 @@ code-example(format, language="html"). Unlike `EvenBetterLogger`, we can't inject the `UserService` into the `HeroService`. The `HeroService` won't have direct access to the user information to decide who is authorized and who is not. + .l-sub-section :marked Why? We don't know either. Stuff like this happens. + :marked Instead the `HeroService` constructor takes a boolean flag to control display of secret heroes. -// #enddocregion providers-factory-1 + +makeExample('dependency-injection/ts/app/heroes/hero.service.ts','internals', 'app/heroes/hero.service.ts (excerpt)')(format='.') -// #docregion providers-factory-2 + :marked We can inject the `Logger`, but we can't inject the boolean `isAuthorized`. We'll have to take over the creation of new instances of this `HeroService` with a factory provider. A factory provider needs a factory function: -// #enddocregion providers-factory-2 + +makeExample('dependency-injection/ts/app/heroes/hero.service.provider.ts','factory', 'app/heroes/hero.service.provider.ts (excerpt)')(format='.') -// #docregion providers-factory-3 + :marked Although the `HeroService` has no access to the `UserService`, our factory function does. We inject both the `Logger` and the `UserService` into the factory provider and let the injector pass them along to the factory function: -// #enddocregion providers-factory-3 + +makeExample('dependency-injection/ts/app/heroes/hero.service.provider.ts','provider', 'app/heroes/hero.service.provider.ts (excerpt)')(format='.') -// #docregion providers-factory-4 + .l-sub-section :marked The `useFactory` field tells Angular that the provider is a factory function whose implementation is the `heroServiceFactory`. - The `deps` property is an array of [provider tokens](#token). + The `deps` property is #{_an} #{_array} of [provider tokens](#token). The `Logger` and `UserService` classes serve as tokens for their own class providers. The injector resolves these tokens and injects the corresponding services into the matching factory function parameters. -// #enddocregion providers-factory-4 -// #docregion providers-factory-5 -- var lang = current.path[1] -- var anexportedvar = lang == 'dart' ? 'a constant' : 'an exported variable' -- var variable = lang == 'dart' ? 'constant' : 'variable' + +- var exportedvar = _docsFor == 'dart' ? 'constant' : 'exported variable' +- var variable = _docsFor == 'dart' ? 'constant' : 'variable' :marked - Notice that we captured the factory provider in #{anexportedvar}, `heroServiceProvider`. + Notice that we captured the factory provider in #{_an} #{exportedvar}, `heroServiceProvider`. This extra step makes the factory provider reusable. We can register our `HeroService` with this #{variable} wherever we need it. In our sample, we need it only in the `HeroesComponent`, - where it replaces the previous `HeroService` registration in the metadata `providers` array. + where it replaces the previous `HeroService` registration in the metadata `providers` #{_array}. Here we see the new and the old implementation side-by-side: -// #enddocregion providers-factory-5 + +- var stylePattern = { otl: /(providers.*),$/gm }; +makeTabs( `dependency-injection/ts/app/heroes/heroes.component.ts, dependency-injection/ts/app/heroes/heroes.component.1.ts`, - null, - `app/heroes/heroes.component (v.3), - app/heroes/heroes.component (v.2)`) + ',full', + `app/heroes/heroes.component (v3), + app/heroes/heroes.component (v2)`, + stylePattern) -// #docregion tokens-1 - -.l-main-section +.l-main-section#token :marked ## Dependency injection tokens @@ -748,105 +717,119 @@ code-example(format, language="html"). In all previous examples, the dependency value has been a class *instance*, and the class *type* served as its own lookup key. Here we get a `HeroService` directly from the injector by supplying the `HeroService` type as the token: -// #enddocregion tokens-1 + +makeExample('dependency-injection/ts/app/injector.component.ts','get-hero-service')(format='.') -// #docregion tokens-2 + :marked We have similar good fortune when we write a constructor that requires an injected class-based dependency. We define a constructor parameter with the `HeroService` class type, and Angular knows to inject the service associated with that `HeroService` class token: -// #enddocregion tokens-2 -+makeExample('dependency-injection/ts/app/providers.component.ts','provider-8-ctor')(format=".") -// #docregion tokens-3 + ++makeExample('dependency-injection/ts/app/heroes/hero-list.component.ts', 'ctor-signature') + :marked This is especially convenient when we consider that most dependency values are provided by classes. -// #enddocregion tokens-3 -// #docregion tokens-non-class-deps-1 -- var lang = current.path[1] -- var objectexamples = lang == 'dart' ? 'a string or list literal, or maybe a function' : 'a string, a function, or an object' -// Is function injection useful? Should we show it? +//- TODO: if function injection is useful explain or illustrate why. :marked ### Non-class dependencies +p + | What if the dependency value isn't a class? Sometimes the thing we want to inject is a + block non-class-dep-eg + span string, function, or object. +p + | Applications often define configuration objects with lots of small facts + | (like the title of the application or the address of a web API endpoint) + block config-obj-maps + |  but these configuration objects aren't always instances of a class. + | They can be object literals + |  such as this one: - What if the dependency value isn't a class? - Sometimes the thing we want to inject is #{objectexamples}. -// #enddocregion tokens-non-class-deps-1 - -// TS/JS only -:marked - Applications often define configuration objects with lots of small facts like the title of the application or the address of a web API endpoint. - These configuration objects aren't always instances of a class. They tend to be object hashes like this one: +makeExample('dependency-injection/ts/app/app.config.ts','config','app/app-config.ts (excerpt)')(format='.') -// TypeScript only? :marked - We'd like to make this `config` object available for injection. + We'd like to make this configuration object available for injection. We know we can register an object with a [value provider](#value-provider). - But what do we use for the token? - We don't have a class to serve as a token. There is no `Config` class. -// Typescript only - -.l-sub-section +block what-should-we-use-as-token :marked - ### TypeScript interfaces aren't valid tokens + But what should we use as the token? + We don't have a class to serve as a token. + There is no `AppConfig` class. - The `CONFIG` constant has an interface, `Config`. Unfortunately, we - cannot use a TypeScript interface as a token: - +makeExample('dependency-injection/ts/app/providers.component.ts','providers-9a-interface')(format=".") - +makeExample('dependency-injection/ts/app/providers.component.ts','provider-9a-ctor-interface')(format=".") - :marked - That seems strange if we're used to dependency injection in strongly typed languages, where - an interface is the preferred dependency lookup key. + .l-sub-section#interface + :marked + ### TypeScript interfaces aren't valid tokens - It's not Angular's fault. An interface is a TypeScript design-time artifact. JavaScript doesn't have interfaces. - The TypeScript interface disappears from the generated JavaScript. - There is no interface type information left for Angular to find at runtime. -// end Typescript only + The `HERO_DI_CONFIG` constant has an interface, `AppConfig`. Unfortunately, we + cannot use a TypeScript interface as a token: + +makeExample('dependency-injection/ts/app/providers.component.ts','providers-9-interface')(format=".") + +makeExample('dependency-injection/ts/app/providers.component.ts','provider-9-ctor-interface')(format=".") + :marked + That seems strange if we're used to dependency injection in strongly typed languages, where + an interface is the preferred dependency lookup key. -// #docregion tokens-opaque-1 - -- var lang = current.path[1] -- var opaquetoken = lang == 'dart' ? 'OpaqueToken' : 'OpaqueToken' -h3 OpaqueToken -p. - The solution is to define and use an !{opaquetoken}. + It's not Angular's fault. An interface is a TypeScript design-time artifact. JavaScript doesn't have interfaces. + The TypeScript interface disappears from the generated JavaScript. + There is no interface type information left for Angular to find at runtime. + +//- FIXME simplify once APIs are defined for Dart. +- var opaquetoken = _docsFor == 'dart' ? 'OpaqueToken' : 'OpaqueToken' +:marked + ### OpaqueToken + + One solution to choosing a provider token for non-class dependencies is + to define and use an !{opaquetoken}. The definition looks like this: -// #enddocregion tokens-opaque-1 + +makeExample('dependency-injection/ts/app/app.config.ts','token')(format='.') + :marked We register the dependency provider using the `OpaqueToken` object: -+makeExample('dependency-injection/ts/app/providers.component.ts','providers-9b')(format=".") -// #docregion tokens-opaque-2 -- var lang = current.path[1] -- var decorated = lang == 'dart' ? 'annotated' : 'decorated' -- var configuration = lang == 'dart' ? '' : 'configuration' -:marked - Now we can inject the #{configuration} object into any constructor that needs it, with - the help of an `@Inject` #{decorator} that tells Angular how to find the #{configuration} dependency value. -// #enddocregion tokens-opaque-2 -+makeExample('dependency-injection/ts/app/providers.component.ts','provider-9b-ctor')(format=".") -// begin Typescript only ++makeExample('dependency-injection/ts/app/providers.component.ts','providers-9')(format=".") + +:marked + Now we can inject the configuration object into any constructor that needs it, with + the help of an `@Inject` #{_decorator}: + ++makeExample('dependency-injection/ts/app/app.component.2.ts','ctor')(format=".") + +- var configType = _docsFor == 'dart' ? 'Map' : 'AppConfig' .l-sub-section :marked - Although it plays no role in dependency injection, - the `Config` interface supports strong typing of the configuration object within the class. -:marked -// end typescript only + Although the !{configType} interface plays no role in dependency injection, + it supports typing of the configuration object within the class. -// Skip for Dart (we have another example) -:marked - Or we can provide and inject the configuration object in our top-level `AppComponent`. -+makeExample('dependency-injection/ts/app/app.component.ts','providers', 'app/app.component.ts (providers)')(format=".") -+makeExample('dependency-injection/ts/app/app.component.ts','ctor', 'app/app.component.ts (constructor)')(format=".") +block dart-map-alternative + :marked + Or we can provide and inject the configuration object in our top-level `AppComponent`. + + +makeExcerpt('app/app.component.ts','providers') + +#optional +:marked + ## Optional dependencies + + Our `HeroService` *requires* a `Logger`, but what if it could get by without + a logger? + We can tell Angular that the dependency is optional by annotating the + constructor argument with `@Optional()`: + ++ifDocsFor('ts') + +makeExample('dependency-injection/ts/app/providers.component.ts','import-optional', '') ++makeExample('dependency-injection/ts/app/providers.component.ts','provider-10-ctor', '')(format='.') + +:marked + When using `@Optional()`, our code must be prepared for a null value. If we + don't register a logger somewhere up the line, the injector will set the + value of `logger` to null. -// #docregion summary .l-main-section :marked ## Summary + We learned the basics of Angular dependency injection in this chapter. We can register various kinds of providers, and we know how to ask for an injected object (such as a service) by @@ -856,20 +839,18 @@ p. We can learn more about its advanced features, beginning with its support for nested injectors, in the [Hierarchical Dependency Injection](hierarchical-dependency-injection.html) chapter. -// #enddocregion summary -// #docregion appendix-explicit-injector-1 -.l-main-section - +.l-main-section#explicit-injector :marked - ### Appendix: Working with injectors directly - We rarely work directly with an injector. - Here's an `InjectorComponent` that does. -// #enddocregion appendix-explicit-injector-1 + ## Appendix: Working with injectors directly + + We rarely work directly with an injector, but + here's an `InjectorComponent` that does. + +makeExample('dependency-injection/ts/app/injector.component.ts', 'injector', 'app/injector.component.ts') -// #docregion appendix-explicit-injector-2 + :marked - The `Injector` is itself an injectable service. + An `Injector` is itself an injectable service. In this example, Angular injects the component's own `Injector` into the component's constructor. The component then asks the injected injector for the services it wants. @@ -896,26 +877,24 @@ p. Framework developers may take this approach when they must acquire services generically and dynamically. -// #enddocregion appendix-explicit-injector-2 -// TypeScript only? Unnecessary for Dart -.l-main-section - -:marked - ### Appendix: Why we recommend one class per file - - Having multiple classes in the same file is confusing and best avoided. - Developers expect one class per file. Keep them happy. - - If we scorn this advice and, say, - combine our `HeroService` class with the `HeroesComponent` in the same file, - **define the component last!** - If we define the component before the service, - we'll get a runtime null reference error. - -.l-sub-section +block one-class-per-file-ts-tradeoffs + .l-main-section#one-class-per-file :marked - We actually can define the component first with the help of the `forwardRef()` method as explained - in this [blog post](http://blog.thoughtram.io/angular/2015/09/03/forward-references-in-angular-2.html). - But why flirt with trouble? - Avoid the problem altogether by defining components and services in separate files. + ## Appendix: Why we recommend one class per file + + Having multiple classes in the same file is confusing and best avoided. + Developers expect one class per file. Keep them happy. + + If we scorn this advice and, say, + combine our `HeroService` class with the `HeroesComponent` in the same file, + **define the component last!** + If we define the component before the service, + we'll get a runtime null reference error. + + .l-sub-section + :marked + We actually can define the component first with the help of the `forwardRef()` method as explained + in this [blog post](http://blog.thoughtram.io/angular/2015/09/03/forward-references-in-angular-2.html). + But why flirt with trouble? + Avoid the problem altogether by defining components and services in separate files.