Simple state management classes

store.ts

import { Observable, BehaviorSubject, Subject } from 'rxjs';

export enum StoreState {
  INIT,
  LOADING,
  READY
}

interface StoreInterface<T> {
  value$: Observable<T>;  
  value: T;
  setValue(newValue: T, newState?: StoreState): void;
}

export class BehaviorState {
  state$: Observable<StoreState>;
  private _stateSubject$: BehaviorSubject<StoreState>;

  protected constructor(initialState: StoreState = StoreState.INIT) {
    this._stateSubject$ = new BehaviorSubject(initialState);
    this.state$ = this._stateSubject$.asObservable();
  }

  get state(): StoreState {
    return this._stateSubject$.getValue();
  }

  setState(newState: StoreState): void {
    this._stateSubject$.next(newState);
  }
}

export class Store<T> extends BehaviorState implements StoreInterface<T> {
  value$: Observable<T>;
  private _valueSubject$: Subject<T>;
  
  protected constructor(initialState?: StoreState) {
    super(initialState);
    this._valueSubject$ = new Subject();
    this.value$ = this._valueSubject$.asObservable();
  }

  get value(): T {
    return this._valueSubject$.getValue();
  }

  setValue(newValue: T, newState?: StoreState): void {
    this._valueSubject$.next(newValue);
    if (newState) {
      super.setState(newState);
    }
  }
}

export class BehaviorStore<T> extends BehaviorState implements StoreInterface<T> {
  value$: Observable<T>;
  private _valueSubject$: BehaviorSubject<T>;
  
  protected constructor(initialValue: T, initialState?: StoreState) {
    super(initialState);
    this._valueSubject$ = new BehaviorSubject(initialValue);
    this.value$ = this._valueSubject$.asObservable();
  }

  get value(): T {
    return this._valueSubject$.getValue();
  }

  setValue(newValue: T, newState?: StoreState): void {
    this._valueSubject$.next(newValue);
    if (newState) {
      super.setState(newState);
    }
  }
}