[英]How to get Value instead of Observable from NGRX Store in TS code
[英]How to get and update data from the ngrx store into Observable variable?
我得到了由@ ngrx / schematics創建的帶有store / reducers / etc的非常簡單的功能模塊。 在此功能模塊中,我有2個組件-表單和項目列表,默認情況下為空,您可以通過表單添加項目。 當我通過表單操作添加某些東西時,reducer獲取有效負載,但第二個組件中的項目列表未更新。
項目列表html:
<section class="sub-list">
<div class="container">
<header class="sub-list--header"><h1>My Subscriptions</h1></header>
<span *ngIf="length$ | async">Subscriptions count - {{ length$ | async }}</span>
<main class="sub-list--content" *ngIf="list$ | async as list">
<div class="sub-list--item" *ngFor="let item of list">
<div class="name">{{ item.name }}</div>
</div>
</main>
</div>
</section>
項目清單組件:
import { Component, OnInit } from '@angular/core';
import { MatSnackBar } from '@angular/material';
import { Store } from '@ngrx/store';
import { Observable } from 'rxjs';
// Store
import * as fromSub from '../../reducers/subscription.reducer';
import * as subActions from '../../actions/subscription.actions';
// Models
import { Subscription } from '../../models/Subscription';
@Component({
selector: 'app-sub-list',
templateUrl: './sub-list.component.html',
styleUrls: ['./sub-list.component.scss']
})
export class SubListComponent implements OnInit {
list$: Observable<Subscription[]>;
length$: Observable<number>;
constructor(
private snackBar: MatSnackBar,
private subStore: Store<fromSub.State>
) {
this.list$ = this.subStore.select('subscriptionsList');
this.length$ = this.subStore.select('length');
}
ngOnInit() {
}
}
表單組件(以防萬一我的操作分派錯誤):
import { Component, OnInit } from '@angular/core';
import { MatSnackBar } from '@angular/material';
import { Store } from '@ngrx/store';
// Store
import * as fromSub from '../../reducers/subscription.reducer';
import * as subActions from '../../actions/subscription.actions';
// Models
import { Subscription } from '../../models/Subscription';
@Component({
selector: 'app-sub-form',
templateUrl: './sub-form.component.html',
styleUrls: ['./sub-form.component.scss']
})
export class SubFormComponent implements OnInit {
name: string;
price: number;
link: string;
date: Date;
constructor(
private snackBar: MatSnackBar,
private subStore: Store<fromSub.State>
) {
this.price = 0;
}
ngOnInit() {
}
addSubscription = (): void => {
// Snackbar test
if (!this.name) {
this.snackBar.open('Name field is empty', 'Close', { duration: 3000 });
return;
}
// if (this.link === '') {}
if (this.price < 0) {
return;
}
if (!this.date) {
this.snackBar.open('Date field is empty', 'Close', { duration: 3000 });
return;
}
const newSub: Subscription = {
name: this.name,
price: this.price,
link: this.link,
date: this.date,
};
this.subStore.dispatch(new subActions.AddSubscription(newSub));
this.snackBar.open('Subscription added', 'Close', { duration: 3000 });
}
}
模塊減速器:
import { SubscriptionActions, SubscriptionActionTypes } from '../actions/subscription.actions';
import { Subscription } from '../models/Subscription';
export interface State {
length: number;
subscriptionsList: Subscription[];
}
export const initialState: State = {
length: 0,
subscriptionsList: [],
};
export function reducer(state = initialState, action: SubscriptionActions): State {
switch (action.type) {
case SubscriptionActionTypes.LoadSubscriptions:
return state;
case SubscriptionActionTypes.AddSubscription:
return Object.assign({}, state, {
subscriptionsList: state.subscriptionsList.concat(action.payload),
length: state.subscriptionsList.length + 1
});
default:
return state;
}
}
因此,這可能是化簡(錯誤的商店更新)或組件(錯誤的選擇或錯誤的提供者)的問題
首先想到的是:
您的全球商店如下所示:
interface RootStore {
subscription: {
subscriptionsList: Array<...>,
length: number;
}
}
因此,當您想要獲取this.lenght$
組件時,必須執行以下操作:
this.lenght$ = this.store.select(rootStore => rootStore.subscription.lenght)
當您訂閱組件中的存儲時,您嘗試在RootStore上獲取length
密鑰。 它不存在,因此您正在訂閱undefined。 分派操作后,它仍然是未定義的,因此您的組件沒有刷新數據。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.