Rxjs : prevent pushing data to subjects from outisde the service

Question

Within my anguular app , i ve this service :

@Injectable()
export class myService{

  myBehaviouSubject= new BehaviorSubject("");


  setData(){
     this.myBehaviouSubject.next("123");
  }

}

Inside my app.component , i m able to get the value , but i want to keep it readonly or editable only inside the service itself , i want to prevent to push any data from component (.next('DATA'))

    @Component({

    })
    export class AppComponent implements OnInit {

      constructor(public myService : MyService) { }

    getData(){
      // GET VALUE
      this.myService.myBehaviouSubject.value
    }

    unwantedMethodToSetValue(){
           // SET VALUE -> i want to prevent this
           this.myService.myBehaviouSubject.next("unwanted value")

    }

}

Suggestions ?

Answer 1

You can keep the observable inside service only by declaring it as private field of a class.

@Injectable()
export class myService {

  private myBehaviouSubject = new BehaviorSubject("");

  // Use this observable inside the app component class.
  myBehaviouSubjectObservable = myBehaviouSubject.asObservable();

  setData() {
    this.myBehaviouSubject.next("123");
  }
}

@Component({

})
export class AppComponent implements OnInit {

  constructor(public myService: MyService) {}

  getData() {
    // You can subscribe to observable and can get value here
    this.myService.myBehaviouSubjectObservable.subscribe((value) => {
      console.log(value);
    })
  }

  unwantedMethodToSetValue() {
    // SET VALUE -> you cannot do this here now.
    this.myService.myBehaviouSubject.next("unwanted value")

  }

}