[英]How do I call into correct store 'collection' with ngrx-store?
我有兩個計數器和網址的數據集合(示例應用程序-試圖學習ngrx)。 我可以正確地拉出並顯示2個商店中的每個商店在其各自的組件中。 使用ngrx-store中的計數器示例,我還可以遞增和遞減計數器。 我為網址添加了一個reducer,現在在action開關中只有一個默認值。
問題:當我增加計數器時,也會觸發url默認操作。 我沒有正確選擇1個減速器上的1個動作。 我怎么做?
可能的答案?:我認為每個異徑管的動作需要不同嗎? 即,“計數器增量”和“ URL增量”相對於使用“增量”的兩個縮減器? 還是有另一種方法?
我是ngrx和rxjs的新手,所以最簡單/最直接的代碼會有所幫助。
// app.module.ts
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import 'rxjs/Rx';
import '@ngrx/core';
import { Store, StoreModule } from '@ngrx/store';
import { AppComponent } from './components/app.component';
import { UrlListComponent, UrlItemComponent, ListComponent, ListItemComponent, CounterComponent } from './components/index'
import { counterReducer, urlReducer} from './reducers/index';
@NgModule({
imports: [
BrowserModule,
FormsModule,
HttpModule,
StoreModule.provideStore({counter: counterReducer, urls: urlReducer})
],
declarations: [ AppComponent, UrlItemComponent, UrlListComponent, ListComponent, ListItemComponent, CounterComponent],
bootstrap: [ AppComponent]
})
export class AppModule {
constructor(){console.log("AppModule");}
}
// app.component.ts
import { Injectable, Component, Output, Input, EventEmitter, ChangeDetectionStrategy } from '@angular/core';
import { HttpModule } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import { Store } from '@ngrx/store';
import { INCREMENT, DECREMENT, RESET, Url } from '../reducers/index';
import { ListComponent, UrlListComponent, CounterComponent} from './index'
export interface AppState {
counter: number;
urls : Url[]
}
@Component({
moduleId: module.id, //system js variable name for relative path
selector: 'my-app',
template: `
<counter-comp [counter]="counter" ></counter-comp>
<url-list [urls]="urls"></url-list>
<list [innerArray]="myarray"></list>
`,
providers: [],
changeDetection: ChangeDetectionStrategy.OnPush
})
export class AppComponent {
counter: number;
urls: Url[];
myarray: number[] = [];
constructor(private store: Store<AppState>){
console.log('AppComponent constructor');
this.store.select(state => state.counter)
.subscribe(data => this.counter = data);
this.store.select(state => state.urls)
.subscribe(data => this.onUrlsEmitted(data));
this.myarray.push(1);
this.myarray.push(2);
this.myarray.push(3);
}
ngOnInit() {
console.log('AppComponent ngOnInit');
}
// executed once user data arrives from the store
public onUrlsEmitted(data:Url[]){
console.log('AppComponent onUrlsEmitted');
this.urls = data;
if(!data || !data.length){
console.log("no url data arrived");
}
}
}
// counter.component.ts
import { Component, Input } from '@angular/core';
import { Url, AppState, INCREMENT, DECREMENT, RESET } from '../reducers/index';
import { Store } from '@ngrx/store';
@Component({
selector: 'counter-comp',
template: `
<div class='counter'>
<div>Current Count: {{ counter }}</div>
<button (click)="increment()">Increment</button>
<button (click)="decrement()">Decrement</button>
<button (click)="reset()">Reset Counter</button>
</div>
`
,
styles:[`
div { width: 100%; }
.counter { background-color: #99bbff; }
`]
})
export class CounterComponent {
@Input() counter: number;
constructor(private store: Store<AppState>){
}
increment(){
console.log("counter.component.ts increment");
this.store.dispatch({ type: INCREMENT });
}
decrement(){
console.log("counter.component.ts decrement");
this.store.dispatch({ type: DECREMENT });
}
reset(){
console.log("counter.component.ts reset");
this.store.dispatch({ type: RESET });
}
ngOnInit() {
console.log('CounterComponent input: ' + this.counter);
}
}
// counter.ts
import { ActionReducer, Action } from '@ngrx/store';
export const INCREMENT = 'INCREMENT';
export const DECREMENT = 'DECREMENT';
export const RESET = 'RESET';
export const counterReducer: ActionReducer<number> = (state: number = 0, action: Action) => {
console.log("counterReducer action.type " + action.type);
console.log(JSON.stringify(state));
switch (action.type) {
case INCREMENT:
return state + 1;
case DECREMENT:
return state - 1;
case RESET:
return 0;
default:
console.log("counterReducer default");
return state;
}
}
// url.ts
import { ActionReducer, Action } from '@ngrx/store';
//export const INCREMENT = 'INCREMENT';
//export const DECREMENT = 'DECREMENT';
//export const RESET = 'RESET';
export interface Url{
id: number;
name: string;
}
let initialState = function(){
return [{id:1, name:"Dina"},{id:2, name:"Wayne"},{id:3,name:"kids"}];
}
export const urlReducer: ActionReducer<Url[]> = (state: Url[] = initialState(), action: Action) => {
console.log("urlReducer action.type " + action.type);
console.log(JSON.stringify(state));
switch (action.type) {
default:
console.log("urlReducer default");
console.log(state);
return state;
}
}
您應該添加distinctUntilChanged
運算符。
this.store.select(state => state.urls).distinctUntilChanged().subscribe(data => this.onUrlsEmitted(data))
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