无法从商店ngrx获取值

时间:2020-05-04 10:32:48

标签: angular typescript ngrx ngrx-store

我正面临NgRx,我不明白如何很难向商店添加值并检索它。无论如何,那是我到目前为止所做的

效果ts:

export class idEffects {

    saveId$ = createEffect(() =>
    this.actions$
        .pipe(
            ofType(idActions.addIdAction),
            tap(payload => {
                console.log("action",payload);
            })
        )
    ,{dispatch: false});

    constructor(
      private actions$: Actions
    ) {}
  }

动作ts:

export const ADD_ID ='[Id操作]添加ID';

export const addIdAction = createAction(
    ADD_ID,
    props<{id: any}>()
)

减速器ts:

export interface IdState {
    id: any;
}

export const defaultId: IdState = {
    id: undefined
};

export const idReducer = createReducer (
    defaultId,

    on(idActions.addIdAction, (state, action) => {
        //console.log("Calling id reducer", action);
        return {
            id: action
        }
    })
)

和选择器ts:

export const selectIdState = 
createFeatureSelector<IdState>("id")

export const selectIdValue = createSelector(
    selectIdState,
    id => id
);

现在,这就是我的app.module.ts

StoreModule.forRoot({id: idReducer}),
    EffectsModule.forRoot([IdEffects]),
    StoreModule.forRoot(reducers, {
      metaReducers
    }),
    StoreDevtoolsModule.instrument({maxAge: 25}),
    StoreRouterConnectingModule.forRoot({
      stateKey: 'router',
      routerState: RouterState.Minimal
    })

似乎存储数据工作良好,因为控制台中的Redux面板返回以下内容:

id(pin):"1"
data(pin):"Hello There"
type(pin):"[Id Action] add id"

但是,当我尝试检索该对象时,我得到一个undefined,并以此方式进行操作:

this.id$ = storeId.pipe(select(selectIdValue))

和html

<h4>The id obj is: {{id$ | async}}</h4>

但是它什么也没写。我尝试使用该组件中的订阅来获取结果,这使我undefined变得可能吗?

1 个答案:

答案 0 :(得分:1)

状态是

export interface IdState {
    id: any;
}

因此选择器应从其功能状态中选择ID

export const selectIdValue = createSelector(
    selectIdState,
    state => state.id, // selectIdState returns an object of IdState interface.
);

然后,化简器应将id道具添加到状态,而不是action

    on(idActions.addIdAction, (state, action) => {
        //console.log("Calling id reducer", action);
        return {
            ...state, // not needed in your case, but a good style.
            id: action.id, // <- .id
        }
    }),

效果,不需要它,您可以将其删除。

,最后是reducers变量。您可以分享其来源吗? 应该是

const reducers = {
  id: idReducer, // id key is important, idReducer is enough for now.
};

也不要忘记在addIdAction某处派遣。 例如在组件的ngOnInit中。

this.store.dispatch(addIdAction({id: 'value'}));

如果您有类似的事情-应该可以。 如果您还有其他问题,请告诉我。