RxJS allows you to combine streams in various ways. This lesson shows you how to take a click stream and combine it with a store stream to use a value from the store inside a reducer.
The logic is when we click the recall button, it will reset all the people‘s time to the current time.
First, bind the click event to recall$:
<button (click)="recall$.next()">Recall</button> ... recall$ = new Subject();
We get the latest time from the time stroe:
constructor(store:Store) { this.time = store.select(‘clock‘); this.people = store.select(‘people‘); Observable.merge( this.click$, this.seconds$, this.person$, this.recall$ .withLatestFrom(this.time, (_, y) => y) // _: means don‘t need to care about the first param which is this.recall$ .map( (time) => ({type: RECALL, payload: time})) ) .subscribe(store.dispatch.bind(store)) }
_: is naming convention, it means, don‘t care about the first value.
Last, we handle the action in reducer:
case RECALL: return state.map( (person) => { return { name: person.name, time: payload }; })
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[Angular 2] Using a Value from the Store in a Reducer
原文：http://www.cnblogs.com/Answer1215/p/5441173.html