Subject Observer Example

FilterService.ts

import {Observer} from 'rxjs/Observer';
import {BehaviorSubject} from 'rxjs/BehaviorSubject';

interface IFilter {
  name: string,
  tags: CollectionMatcher
}

export class FilterService {
  private _filters = new BehaviorSubject<IFilter>({
    name: '',
    tags: {
      values: [],
      allMustMatch: false
    }
  })
  
  public changeFilters(filters) {
    this._filters.next(filters)
  }
  
  public getFilters(prop?: string): BehaviorSubject<IFilter> {
    if (prop)
      return this._filters.map((filters: IFilter) => _.get(filters, prop))
    else
      return this._filters
  }
  
  public subscribe(fn) {
    return this._filters.subscribe(fn)
  }
}

ObserverImpl.ts

class ObserverImpl implements Observer {

  public next(result: any) {
    console.log(`result: ${result}`);
  };

  public error(err: any) {
    console.log(`error: ${err}`);
  };

  public complete() {
    console.log('Completed');
  }
}

SomeClass.ts

import {FilterService} from './FilterService';
import {ObserverImpl} from './ObserverImpl';

export class SomeClass {

  private subscription: ISubscription;

  constructor(private filterService: FilterService, private $scope: any) {
    this.subscription = this.filterService.subscribe(new ObserverImpl());
    $scope.$on('$destroy', () => this.subscription.unsubscribe();
  }
  
  /* moar stuff  */
  
}