Accessing child class members

[axos88]

Is it possible to write something like this oversimplified snippet:

  class Filterable<T, F> {
    protected service: CrudService<T>

    protected filter$ = new BehaviourSubject<F>(null);
    protected filteredData$ = filter$.pipe(switchMap(f => this.service.filteredBy(f)) // use of this.service before initialization

    filter(f: Partial<F>) {
      this.filter$.next(f)
    }

  class ConcreteService extends CrudService<Foo, FooFilter> { ... }
  
  class Controller extends Mixin(Filterable<Foo, FooFilter>, XXX) {
    protected service = new ConcreteService(...);

    (... random uses of filter() and filteredData$ )
  }

[andres-flores-espol]

I don't think it's possible since you're using the instance this inside the Filterable class block. There's no bind that can override that this with the one from the Controller class. Perhaps if you use the initFunction you can bind the controller with the function you expect to use, for example something like

settings.initFunction = 'init';

class Filterable<T, F> {
    protected service: CrudService<T>

    protected filter$ = new BehaviourSubject<F>(null);
    protected filteredData$: ReturnType<BehaviourSubject<F>['pipe']>
    filter(f: Partial<F>) {
      this.filter$.next(f)
    }

    protected init() {
       // At this point `this` should be the `Controller` instance.
       this.filteredData$ = this.filter$.pipe(switchMap(f => this.service.filteredBy(f))
    }

}

class ConcreteService extends CrudService<Foo, FooFilter> { ... }
  
class Controller extends Mixin(Filterable<Foo, FooFilter>, XXX) {
    protected service = new ConcreteService(...);

    (... random uses of filter() and filteredData$ now binded to this controller )
}