purchase-contract.effects.ts

loadPurchaseContract$ = createEffect(
    () =>
      this.actions$.pipe(
        ofType(PurchaseContractActions.loadPurchaseContract),
        map(action => action.address),
        switchMap(address => {

          return this.purchaseSrv.loadPurchaseContract(address).pipe(
            map(contract =>
              PurchaseContractActions.loadPurchaseContractSuccess({ contract })),
            catchError((err: Error) =>
              of(ErrorActions.errorMessage({ errorMsg: err.message }), SpinnerActions.hide())
            ))
        })

      ));