使用的技术 - Angular 4,rxjs 试图实现 - 从两个不同的服务器获取数据(json响应),合并数据并通过将列表与可观察数组绑定在列表中显示。
**Search component TS**
@Component({
selector: 'word-search',
templateUrl: 'wordSearch.component.html',
})
export class WordSearchComponent {
term = new FormControl();
items: Observable<Array<string>>;
constructor(private wikipediaService: WikipediaService) { }
ngOnInit() {
this.items = this.term.valueChanges
.debounceTime(1000)
.distinctUntilChanged()
.switchMap(term => this.wikipediaService.search(term));
}
}
*****Search component chtml*****
<div>
<h2>Search</h2>
<input type="text" [formControl]="term"/>
<ul>
<li *ngFor="let item of items|async ">{{item}}</li>
</ul>
</div>
服务代码 - 问题在这里
getWikipediaObserver(term:string):Observable<any>
{
var wikipediaUrl = 'http://en.wikipedia.org/w/api.php?callback=JSONP_CALLBACK';
var search = new URLSearchParams()
search.set('action', 'opensearch');
search.set('search', term);
search.set('format', 'json');
return this.jsonp
.get(wikipediaUrl, { search })
.map((request) => request.json()[1]).catch(this.handleError);
}
getItuneObserver(term: string)
{
var secondUrl = 'https://itunes.apple.com/search?callback=JSONP_CALLBACK&limit=20';
var search = new URLSearchParams()
search.set('term', term);
search.set('format', 'json');
var ituneObserver = this.jsonp
.request(secondUrl, { search })
.map((request) => request.json().results.map(item => {
return item.trackName + " " +item.collectionCensoredName+" " +item.artistName;
})).catch(this.handleError);
return ituneObserver;
}
search(term: string): Observable<any> {
var observer1= this.getItuneObserver(term);
var observer2= this.getWikipediaObserver(term);
return merge(observer1,observer2); ***//PROBLEM***
}
合并运算符两次发出值,一次针对第一个观察者,然后针对 第二位观察员。列表将首先显示第一组并使用新项目覆盖旧项目。我想合并只发出一次所有数据。任何想法?
答案 0 :(得分:0)
您可以使用forkJoin方法连接多个observable,这是rxjs库
// import { forkJoin } from 'rxjs/observable/forkJoin';
forkJoin(
this.this.getItuneObserver(term),
this.getWikipediaObserver(term)
)
.subscribe(([res1, res2]) => {
this.propOne = res1;
this.propTwo = res2;
});
答案 1 :(得分:0)
感谢Pramod Patil。我是如何解决的
search(term: string) {
const combined =forkJoin(
this.getItuneObserver(term),
this.getWikipediaObserver(term)
);
return combined;
}
订阅了component.ts
import { of } from 'rxjs/observable/of';
export class WordSearchComponent {
term = new FormControl();
items: Observable<Array<string>>;
result: string[] = [];
ngOnInit() {
var combined=this.term.valueChanges
.debounceTime(1000)
.distinctUntilChanged()
.switchMap(term => this.wikipediaService.search(term));
combined.subscribe(latestValues => {
const [ response1 , response2 ] = latestValues;
this.result=this.result.concat(response1);
this.result=this.result.concat(response2);
this.items = of(this.result);
});
}