Feature request : Allow properties Injection

🚀 feature request

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Performance issue
[x] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question
[ ] Other... Please describe:

Description

Give the possibility to inject somthing without using constructor

Current behavior

All the dependencies must be injected in constructor:

Expected behavior

Add new annotation @Autowire for the property which can be present with @Optional, for example:

export class MyClass {
  @Autowire
  private mainClass: MainClass;
}

Current solution

1. Defining a class SingletonLocator

export class SingletonLocator {
  public static injector: Injector = undefined;
}

1. Add in AppModule

export class AppModule {
    constructor(injector: Injector) {
        SingletonLocator.injector = injector;
    }
}

1. Retrive Singleton in a Component

@Component(..)
export class MyComponent {
 
    private myService: MyService;

   constructor() {
     this.myService = SingletonLocator.get(MyService);
  }
}

[alxhub]

This is on our roadmap 😃

[splincode]

@mascoun https://www.npmjs.com/package/@angular-ru/autowired