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我在這裏試圖在我的用戶服務上循環觀察對象。 的Chrome瀏覽器的控制檯拋出:錯誤嘗試循環Angular 2中的Observable對象
error_handler.js:47 EXCEPTION: undefined is not a function
這裏是我的代碼:
users.component.ts
import { Component, OnInit } from '@angular/core';
import { UserService } from '../user.service';
import { Observable } from 'rxjs/Rx';
import { User } from '../user';
@Component({
selector: 'app-users',
templateUrl: './users.component.html',
styleUrls: ['./users.component.css']
})
export class UsersComponent implements OnInit {
people: Observable<User[]>;
constructor(private _userService: UserService) { }
ngOnInit() {
this.people = this._userService.getAll();
console.log(this.people);
}
}
users.service.ts
import { Injectable } from '@angular/core';
import { Http, Response, Headers } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import { ErrorObservable } from 'rxjs/observable/ErrorObservable';
import { User } from './user';
@Injectable()
export class UserService {
private baseurl: string= 'http://swapi.co/api';
constructor(private http: Http) {
console.log("User service initialized");
}
getAll(): Observable<User[]>{
let users$ = this.http
.get(`${this.baseurl}/people`,{headers: this.getHeaders()})
.map(this.mapUsers);
return users$;
}
private getHeaders(){
let headers = new Headers();
headers.append('Accept', 'application/json');
return headers;
}
mapUsers(response: Response): User[]{
return response.json().results.map(this.toUser);
}
toUser(r:any): User{
let user = <User>({
id: this.extractId(r),
name: r.name
});
console.log('Parsed user'+user.name);
return user;
}
extractId(personData:any){
let extractedId = personData.url.replace('http://swapi.co/api/people/','').replace('/','');
return parseInt(extractedId);
}
}
users.component.html
<ul class="people">
<li *ngFor="let person of people | async " >
<a href="#">
{{person.name}}
</a>
</li>
</ul>
個
user.ts
export interface User{
id: number;
name: string;
}
當我從模板中刪除HTML代碼,一切(控制檯上沒有錯誤)的偉大工程的話,我想沒有什麼毛病「人」的對象,很明顯,我可以不會迭代響應。請大家,一手將在這裏讚賞。
謝謝pesskillet yor回覆。很高興知道..我會記住它。我修改了函數,更新了地圖調用:.map(this.mapUsers.bind(this)); ...但現在控制檯拋出: 未捕獲的錯誤:模塊構建失敗:錯誤:/home/webdeveloper/Workspace/Angular2/unibague_directory_v2/src/app/user.service.ts(26,14):Type'Observable <{}> '不可分配鍵入'Observable'。 類型'{}'不可分配爲鍵入'User []'。 –
如果我使用第二個選項(res =>),我的代碼編輯器(visual studio)強調了「響應」一詞。 (變量未聲明) –
嗯,是的,這是一個錯字。它應該是'響應',而不是'res' –