角度：ngrx 效果未触发

Question

我已经开发了一些实现 Redux (NgRx) 的 Angular 应用程序。 我无法弄清楚我当前项目的问题。

行动：

export class GetUserFromStorage implements Action {
  readonly type = UserActionTypes.GetUserFromStorage;
}

export class GetUserFromStorageSuccess implements Action {
  readonly type = UserActionTypes.GetUserFromStorageSuccess;
  constructor(public payload: User | null) { }
}

export class GetUserFromStorageFail implements Action {
  readonly type = UserActionTypes.GetUserFromStorageFail;
  constructor(public payload: string) { }
}

减速器：

case UserActionTypes.GetUserFromStorageSuccess:
    return {
        ...state,
        user: action.payload,
        error: ''
    };

case UserActionTypes.GetUserFromStorageFail:
    return {
        ...state,
        error: action.payload
    };

效果：

@Effect() getUserFromStorage$:
Observable<userActions.GetUserFromStorageSuccess | userActions.GetUserFromStorageFail>
    = this.actions$.pipe(
        ofType(userActions.UserActionTypes.GetUserFromStorage),
        tap(() => console.log('GETUserToStorage$', )),
        mergeMap((action: userActions.GetUserFromStorage) =>
            this.storageService.getItem(StorageKeys.USER).pipe(
                map((user: User | null) =>
                    new userActions.GetUserFromStorageSuccess(user)),
                catchError((error: string) =>
                    of(new userActions.GetUserFromStorageFail(error)))
                ))
            );

在 auth.service.ts 中，我订阅了 Store 并分派了一些操作。

this.store.dispatch(new userActions.GetUserFromStorage());

this.store.pipe(select(userReducer.getUser)).subscribe(
    (user: User) => {
        console.log('user TEST: ', user);
        this.user = user;
    }
);

我安装了 ReduxDevTools。 GetUserFromStorage 操作会触发，但不会触发 getUserFromStorage$ 效果。 “user TEST”的 console.logged 值显示“user”为“null”。 任何想法，任何人？ 谢谢你。

Answer 1

确保您确实“激活”了它们。

注射效果：

@Injectable()

export class FooEffects {

  @Effect() getUserFromStorage$:
Observable<userActions.GetUserFromStorageSuccess | userActions.GetUserFromStorageFail>
    = this.actions$.pipe(
        ofType(userActions.UserActionTypes.GetUserFromStorage),
        tap(() => console.log('GETUserToStorage$', )),
        mergeMap((action: userActions.GetUserFromStorage) =>
            this.storageService.getItem(StorageKeys.USER).pipe(
                map((user: User | null) =>
                    new userActions.GetUserFromStorageSuccess(user)),
                catchError((error: string) =>
                    of(new userActions.GetUserFromStorageFail(error)))
                ))
            );
}

app.module.ts ：

import {EffectsModule} from '@ngrx/effects';

imports: [
  EffectsModule.forRoot([
    FooEffects
  ])
]