角2個RXJS觀察到

Question

我必須在這裏的東西超級明顯...

public suggestedData$: Observable<string[]>; 
public suggestionStream = new Subject<string>(); 

nextSuggestion(){ 
    this.suggestionStream.next(this.query); 
} 

this.suggestionStream 
    .map(query => { 
     return this._someService.getSomeThings(query); 
    }); 

this.suggestionData$ = this.suggestionStream.subscribe(); 

然後在模板我想使用可觀察到的是這樣的：

<ul> 
    <li *ngFor="let suggestion of suggestionData$ | async">{{suggestion.something}}</li> 
</ul> 

的Visual Studio說：Type 'Subscription' is not assignable to type 'Observable<string[]>'.爲this.suggestionData$ = this.sug...

任何想法？

編輯：

this.suggestionStream 
    .map(query => { 
     console.log(query); 
      return this._someService.getSomeThings(query); 
     }) 
     .subscribe(res => { 
      console.log('res', res); 
     }); 

打印控制檯：

res Observable {_isScalar: false, source: Observable, operator: MapOperator}

_someService看起來是這樣的：

getSomeThings(query: string){ 

    let params = new URLSearchParams(); 
    params.set('query', query); 

    return this.http.get('https://api.../suggest', {search: params}) 
     .map(res => res.json() || []); 

} 

Answer 1

this.suggestionStream.subscribe()的類型是認購，而不是一個觀察的。所以我認爲你想要達到的效果如下：

public suggestedData$: new Observable<string[]>; 
public suggestionStream = new Subject<string>(); 

nextSuggestion(){ 
    this.suggestionStream.next(this.query); 
} 

this.suggestionData$ = this.suggestionStream 
    .map(query => { 
    return this._someService.getSomeValues(query); 
    }); 

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