为ngrx/data实体创建选择器 [英] create a selector for a ngrx/data entity

问题描述

我有一个状态，我想从ngrx/data实体创建选择器.

I have a state and I'd like to create selectors from ngrx/data entities.

import {
  Action,
  ActionReducer,
  ActionReducerMap,
  createFeatureSelector,
  createSelector,
  MetaReducer
} from '@ngrx/store';
import {environment} from '../../environments/environment';
import * as fromRouter from '@ngrx/router-store';
import * as fromDrawer from './drawer';
import {InjectionToken} from '@angular/core';
import {NavigationItem} from '../models/navigation-item';

export interface State {
  router: fromRouter.RouterReducerState<any>;
  drawerNavigationItems: fromDrawer.State;
}

export const ROOT_REDUCERS = new InjectionToken<ActionReducerMap<State, Action>>('Root reducers token', {factory: () => ({
    router: fromRouter.routerReducer,
    drawerNavigationItems: fromDrawer.reducer,
  }),
});

export const metaReducers: MetaReducer<State>[] = !environment.production ? [] : [];

export const selectRouter = createFeatureSelector<
  State,
  fromRouter.RouterReducerState<any>
  >('router');

const {
  selectQueryParams,    // select the current route query params
  selectQueryParam,     // factory function to select a query param
  selectRouteParams,    // select the current route params
  selectRouteParam,     // factory function to select a route param
  selectRouteData,      // select the current route data
  selectUrl,            // select the current url
} = fromRouter.getSelectors(selectRouter);

export const selectRouteId = selectRouteParam('id');
export const selectStatus = selectQueryParam('status');


// Drawer

export const selectDrawerNavigationItems = (state: State) => state.drawerNavigationItems.items as NavigationItem[];

如何使用预定义的选择器或使用来自ngrx/data的实体或服务编写自己的选择器?

How do I use the pre-defined selectors or write my own with entities or services that came from ngrx/data?

作为一个示例，我想创建一个选择器来选择所有社区"实体，然后在步骤2中按selectRouteId选择1. 如果您想象路由/communities/:id，则selectRouteId返回ID，现在我想要来自CommunityService的数据，并使用在步骤1中创建或以某种方式导入和使用的选择器并返回结果1 与selectRouteId的ID，因此以后我可以做类似this.store.dispatch(selectCommunityByCurrentRouteId);

As an example I'd like to create a selector that selects all "Community" entities and then, step 2, select 1 by selectRouteId. If you imagine a route /communities/:id, selectRouteId returns the Id, and now I'd like the data from the CommunityService and use the selector created or somehow imported and used in step 1 and return a result, 1 Community with the selectRouteId's id, so I can later do something like this.store.dispatch(selectCommunityByCurrentRouteId);

此问题特定于@ ngrx/data.

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