我创建了一个服务来获取搜索结果 . 函数名是getSearchResults,用于获取搜索结果,我有一个组件,我订阅了函数'getSearchResults . 我还有一个名为'searchResults'的Observable,我订阅它以获得我的组件中的实际结果 . 当我订阅searchResults变量时,我得到订阅而不是函数错误 . 有时它工作正常但是当我点击浏览器上的后退按钮时它会显示错误 .
服务:
import { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
import { Observable } from 'rxjs/Observable';
import { Http, Response, Headers, RequestOptions, URLSearchParams } from '@angular/http';
import { Router } from '@angular/router';
import { AppConfig } from '../app.config';
@Injectable()
export class SearchResultsService {
// Observable string source
private searchResultsSource = new BehaviorSubject<any>({"results": "null"});
// Observable string stream
searchResults: Observable<any>;
constructor(
private router: Router,
private http: Http,
private config: AppConfig) {
this.searchResults = this.searchResultsSource.asObservable();
}
getSearchResults(query: string, field: string) {
if(sessionStorage.getItem('searchResults')) {
sessionStorage.removeItem('searchResults');
console.log('removed');
}
else console.log('not removed');
if (field == null || !field)
field = '_all';
if (query == null || !query)
return;
let token = JSON.parse(localStorage.getItem('authDetails')).accessToken;
let headers = new Headers({ 'Authorization': token,
'Access-Control-Allow-Origin': '*'});
let params: URLSearchParams = new URLSearchParams();
params.set('q', query);
params.set('f', field);
let options = new RequestOptions({ headers: headers,
search: params
});
return this.http.get(this.config.apiUrl+'/search', options)
.map((response: Response) => {
console.log('response received');
this.searchResults = response.json();
sessionStorage.setItem('searchResults', JSON.stringify(this.searchResults));
console.log((response.json()).results);
this.emitSearchResults();
},
error => console.log(error));
}
emitSearchResults(): void {
this.searchResultsSource.next(this.searchResults);
}
}
零件:
import { Component, OnInit, OnDestroy, DoCheck } from '@angular/core';
import { Router, ActivatedRoute } from '@angular/router';
import 'rxjs/add/operator/map';
import { SearchResultsService } from '../services/search-results.service';
@Component({
moduleId: module.id,
selector: 'app-search-results',
templateUrl: './search-results.component.html',
styleUrls: ['./search-results.component.css']
})
export class SearchResultsComponent implements DoCheck, OnInit {
public searchResults;
public searchResultsCount: number = 0;
public subscription;
public field: string;
public query: string;
constructor(
private searchResultsService: SearchResultsService,
private router: Router,
private route: ActivatedRoute) {
console.log('on top');
if(JSON.parse(sessionStorage.getItem('searchResults')))
this.searchResults = JSON.parse(sessionStorage.getItem('searchResults'));
this.searchResultsService.searchResults.subscribe(
(results) =>
this.searchResults = results);
this.searchResults = this.searchResultsService.searchResults;
this.field = this.route.snapshot.params['field'];
this.query = this.route.snapshot.params['query'];
console.log('in search results constructor');
console.log(this.searchResults);
}
ngOnInit() {
this.searchResultsService.getSearchResults(this.query, this.field).subscribe(
(data) => {
console.log('subs work');
},
(error) => {
console.log('subs ot work');
});
}
onClick() {
this.subscription.unsubscribe();
console.log('destroyed');
}
ngDoCheck() {
}
}
3 回答
它可能与您定义订阅的方式有关 . 试试这个
然后它应该工作得很好 .
我还注意到您正在尝试订阅不存在的方法 . 您的服务中只有
emitSearchResults(): void
和getSearchResults
.我还将变量定义为不在构造函数内但在类似这样的类中的observable
问题是我使用相同的变量作为observable以及存储搜索结果 . 我创建了另一个变量来存储搜索结果,现在修复了错误 .
@NitinSingh我没有足够的代表来添加评论,所以我必须在这里回复 .
问题在于http.get调用的响应映射 . 不要
this.searchResults = response.json();
来设置this.searchResults
的值 . searchResults正在观察searchResultsSource,因此您可以通过在.map中执行this.searchResultsSource.next(response)
来更改观察值 .它看起来像这样
也不应在构造函数中声明
this.searchResults = this.searchResultsSource.asObservable();
.