Manual pages because you like reinventing the wheel

paging.ts

interface IItem {
  page: number;
  content: number;
}

class Paging {

  const ITEM_LIMIT: number = 10;
  const CONTENT_FILTER: number = 2;
  const content$: Subject<IItem[]>;
  const filteredContent$: Observable<IItem[]>;

  let pageCounter: number = 0;

  constructor() {
    this.content$ = new Subject<IItem[]>();
    this.filteredContent$ = this.content$.pipe(
      map(items => _.filter(items, i => i.content === this.CONTENT_FILTER)),
      tap(filteredItems => 
        if(filteredItems.length < this.ITEM_LIMIT) this._getNextPage()
      ),
    )
  }
  
  /*
   * PRIVATE FUNCTIONS
   */
  private _getNextPage(): Observable<IItem[]> {
    for(let i = 0; i < 10; i++ ) {
     this.content$.next({
      page: pageCounter,
      content: i,
     });
    }
    this.pageCounter++;
    return content$;
  }
}