CODEWITHSUNDEEP
angulartypescriptextendsangular2-servicesangular2-http
Han Che
Han Che

Reputation: 8519

can a class extend a service and be instantiated with new keyword in angular 2?

Hi I have a Service like

@Injectable()
export class ParentService{

  constructor(private http:Http){}

  get(){this.http.get(...)}
}

can I create a class which extends the service? e.g.

export class SomeClass extends ParentService {
  public name:string;
  constructor(name:string, private http:Http){
    super(http);
    this.name = name;
  }
}

and use the new keyword to instantiate inside a component like

export class Cmp{
  instance:any;
  constructor(){
    this.instance = new SomeClass('InstanceOne', ?? )
    this.instance.get();
  }
}

The idea is that with each new instance I can pass a string as urlPath and use that instance to call generic functions from my service. Thanks!

Upvotes: 2

Views: 970

Answers (1)

Günter Zöchbauer
Günter Zöchbauer

Reputation: 657721

If you want DI to pass a constructor parameter, then you need to delegate instantiation to Angulars DI.

What you can do is 

export class Cmp{
  instance:any;
  constructor(http:Http){
    this.instance = new SomeClass('InstanceOne', http);
    this.instance.get();
  }
}

Or alternatively you can provide a string and use @Inject('sometoken') to get name passed in by DI when it creates a new SomeClass.

Upvotes: 1

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