angular2-di-helper

An implementation of the dependency injection helpers at Angular2 (2.0.0 compatible).

Installation

First you need to install the npm module:

npm install angular2-di-helper --save

Use

In general, you don't need configure the providers at the main application module. You have to configure your providers at the main application module only if you use the Singleton annotation.

Use case #1

So, we should integrate the DI module at first.

import {DIModule} from 'angular2-di-helper';

@NgModule({
    imports: [
        DIModule,
        ...
    ],
    providers: [Action],      // Put here your Action if you use the Singleton annotation
    ...
})
export class ApplicationModule {
}

Create the Action as a singleton instance via the factory using @Singleton decorator.

import {Singleton} from 'angular2-di-helper';

@Singleton()
@Injectable()
export class Action {

    constructor(...) {
    }
}

Create the Action2 instance every time as a new instance via the factory.

@Injectable()
export class Action2 {

    constructor(...) {
    }
}

@Injectable()
export class ActionFactory {

    constructor(@Inject(ServiceLocator) private serviceLocator:IServiceLocator) {
    }

    public createAction<TAction>(ctor:{new (...type:Type<any>[]):TAction}):TAction {
        return this.serviceLocator.getService<TAction>(ctor);
    }
}

Use case #2

You have to configure your providers at the main application module using service locator only if you have a "special configuration" of providers, for example:

class DiClass {
    constructor() {
    }
}

class DiClass1 extends DiClass {
    constructor() {
        super();
    }

    methodOfClass1():void {
        console.log('Method is called');
    }
}

@NgModule({
    imports: [DIModule, ...],
    providers: []               // Empty providers section at the main application module!
})
export class ApplicationModule {
    constructor(@Inject(ServiceLocator) serviceLocator:IServiceLocator) {
        serviceLocator.configure([{     // Configures only the service locator!
            provide: DiClass,
            useClass: DiClass1
        }]);
    }
}

@Component(...)
export class AppComponent {
    constructor(@Inject(ServiceLocator) private serviceLocator:IServiceLocator) {
        const instance1:DiClass1 = this.serviceLocator.getService(DiClass);
        const instance2:DiClass1 = this.serviceLocator.getService(DiClass);
    
        instance1.methodOfClass1();                             // Console output: "Method is called"
        instance2.methodOfClass1();                             // Console output: "Method is called"
        console.log(instance1 === instance2);                   // Console output: "false"
    }

Publish

npm run deploy

License

Licensed under MIT.