purchase-contract.effects.ts

removeProduct$ = createEffect(
    () => 
        this.actions$.pipe(
        ofType(PurchaseContractActions.removePurchaseContract),
        map(payload => payload.key),
        switchMap(key => {

          const dialogConfig = new MatDialogConfig();
          dialogConfig.width = '420px';
          dialogConfig.disableClose = true;
          dialogConfig.autoFocus = true;
          dialogConfig.data = {
            title: 'Confirm Remove',
            content: `Are you sure to remove contract ${key} from market?`,
            output: key
          };

          const dialogRef = this.dialog.open(ConfirmDialogComponent, dialogConfig);
          return dialogRef.afterClosed();
        }),
        exhaustMap(result => {

          if (result === undefined) {
            return of(SpinnerActions.hide());
          }

          return this.fleaSrv.removePurchaseContract(result).pipe(
            tap(productKey => console.log(`Contract has been removed: ${productKey}`)),
            concatMap(productKey =>
              [PurchaseContractActions.removePurchaseContractSuccess({ key: productKey }),
              // update ballance
              Web3ProviderActions.getBalance()]
            ),
            catchError((err: Error) =>
              of(ErrorActions.errorMessage({ errorMsg: err.message }), SpinnerActions.hide(),
                // update ballance
                Web3ProviderActions.getBalance())
            )
          )
        })
      ));