Question

我使用角度6和Ngrx效果。其登录效果

@Effect({dispatch: false})
login$ = this.actions$.pipe(
    ofType<Login>(AuthActionTypes.Login),
    tap(action => {
        localStorage.setItem(environment.authTokenKey, action.payload.authToken);
        console.log('login effect');
        this.store.dispatch(new UserRequested());
    }),
);

已调度用户请求效果

@Effect({dispatch: false})
loadUser$ = this.actions$
.pipe(
    ofType<UserRequested>(AuthActionTypes.UserRequested),
    withLatestFrom(this.store.pipe(select(isUserLoaded))),
    filter(([action, _isUserLoaded]) => !_isUserLoaded),
    mergeMap(([action, _isUserLoaded]) => this.auth.getUserByToken()),
    tap(data => {
        console.log('login effect');
        if (data) {
            this.store.dispatch(new UserLoaded({ user: data['user'] }));
            localStorage.setItem('options', JSON.stringify(data['options']));
            // localStorage.setItem("permissions", data['user'].permissions_list);
            data['user'].permissions_list.forEach((item) => {
                this.permissionsService.addPermission(item.name);
            });
        } else {
            this.store.dispatch(new Logout());
        }
    }, error => {
        this.store.dispatch(new Logout());
    })
  );

如果此效果被调用并且至少一次失败，则不会再次调用。为什么？

Answer 1

因为需要控制流。如果流有错误，它将按预期停止。

如果您不希望它停止，请考虑将catchError运算符与throwError函数一起使用，或者只是在订阅中捕获错误。

实时观看：

不起作用

rxjs.throwError('mocked error')
  .subscribe(
    () => console.log('You should not see this message'),
  )

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.5.3/rxjs.umd.js"></script>

工作

rxjs.throwError('mocked error')
  .subscribe(
    () => console.log('You should not see this message'),
    () => console.log('You should see this message')
  )

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.5.3/rxjs.umd.js"></script>

有效的BIS

rxjs.throwError('mocked error')
  .pipe(rxjs.operators.catchError(err => rxjs.of('some mocked replacement value')))
  .subscribe(
    () => console.log('You should see this message'),
    () => console.log('You should not see this message')
  )

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.5.3/rxjs.umd.js"></script>

如果一次失败，为什么角度ngx效果不起作用？

1 个答案: