Angular 2从API到数组获取JSON数据

Question

我需要将JSON数据提取到数组中，并按下按钮来创建新列表。 有什么办法吗？

import { Component } from '@angular/core';
import { RandomService } from '../services/random.service';

@Component({
selector: 'pocetna',
template: `
<ul>
<li *ngFor="let joke of jokes">{{joke.value}}</li>
</ul>
<button (click)="getJoke()">more jokes</button>`,

providers: [RandomService]
})
export class PocetnaComponent  { 
jokes:Joke[] = [];

constructor(private jokesService: RandomService){}

ngOnInit() {
this.getJoke()
}

getJoke() {
this.jokesService.getRandomJokes()
.subscribe(joke => {
   this.jokes.unshift(joke)
})    
}
}
interface Joke{
id: number;
value: string;
}

这就是我的服务的样子，我想我在其中缺少一些东西

import { HttpModule } from '@angular/http';
import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import 'rxjs/add/operator/map';

@Injectable()
export class RandomService {
constructor(private http: Http){
console.log('working');
}
getRandomJokes(){
 return this.http.get('https://api.chucknorris.io/jokes/random')
.map(res => res.json()) 
.map(joke => <Joke>{id: joke.id, value: joke.value});
}

}

这段代码在重新启动应用程序之前有效，但是现在这行代码表明找不到：

.map(joke => <Joke>{id: joke.id, value: joke.value});

Answer 1

我认为您正在尝试将api中返回的json通过json转换为array循环并将其转换为array

 loadMore() {
        this.jokes = this.service.getRandomJokes()
            .subscribe(joke => { 
 const getdata = [];
 for(let key in data){
getdata.push(data[key]);
} 
this.jokes =getdata
});
    }

Answer 2

https://api.chucknorris.io/jokes/random它是对对象的响应。

用数组做出回应

[
    {
      "category": null,
      "icon_url": "https://assets.chucknorris.host/img/avatar/chuck-norris.png",
      "id": "RPVWYzLySH277dwK-Se3PQ",
      "url": "http://api.chucknorris.io/jokes/RPVWYzLySH277dwK-Se3PQ",
      "value": "Chuck Norris is allowed to draw pictures of Mohammad"
    }
]

Answer 3

我想您在响应中解析数据时遇到了问题。

您可以尝试以下方法：

 .map(res => res.json()) .subscribe( data => console.log(data), err => console.log(err), () => console.log('Random Quote Complete') ); 

要么：

 .map((res: Response) => { let data = (res.json() || {}).data; return data; });