PaginatedMyObjectSource.ts

export interface IPageMetadata {
    position: {
        current: number,
        max: number
      },
      data: {
        per: number,
        total: number
      }
}

export interface IPagedResponse<T> {
    data: T[];
    page: IPageMetadata;
  }

export class PagedMyObjectDatasourceService implements DataSource<MyObject> {
  
    private myObjectSubject = new BehaviorSubject<MyObject[]>([]);
    private metadataSubject = new BehaviorSubject<IPageMetadata>({position:{current:0,max:0}, data:{per:0, total:0}})
  
    public metaData$ = this.metadataSubject.asObservable();

    constructor(private myObjectService: MyObjectService){}

    connect(collectionViewer: CollectionViewer): Observable<MyObject[]> {
        return this.myObjectSubject.asObservable();
    }

    disconnect(collectionViewer: CollectionViewer): void {
        this.myObjectSubject.complete();
        this.metadataSubject.complete();
    }

    loadObjects() {
        this.myObjectService.fetchRemoteObjects()
        .pipe(
            catchError(() => of([]))
        )
        .subscribe ( (result : IPagedResponse<MyObject> => {
            this.myobjectSubject.next(result.data);
            this.metadataSubject.next(result.page);
        }
        );
    }
}