find() {
   return this._http.get('api/items')
          .map((res:Response) => res.json())
          .publishReplay(1)
          .refCount();
}

ngOnInit() {
    this.itemService.find().subscribe((data) => {
      this.gridOptions.rowData = data;
      this.loaded = true;
    });
}

ngOnInit() {
        let find = this.byType ? this.itemService.findByType : this.itemService.find;
        find(this.filter).subscribe((data) => {
          this.gridOptions.rowData = data;
          this.loaded = true;
        });
    }