json - json 的 Angular 5 [object Object] 错误

Question

我正在尝试使用 Angular 5 中的 get 通过 httpclient 加载 json 数据。我正在使用服务、接口(interface)、组件和 json 文件；我已经按照一些教程尝试让它工作，并用 jsonlint 验证了我的 json .据我所知，一切都应该正常运行，json 应该被解析，一切都应该没问题，除了我每次都在控制台中收到 'error: [object Object]' .我尝试了各种方法来修复它，例如

data => this.jsonArticles = Object.values(data);
this.articles = data[0];

但我无法将我的数据转换成任何其他形式。

文章.service.ts

import { Injectable } from '@angular/core';
import { Article } from './article';
import { Observable } from 'rxjs/Observable';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class ArticleService {

  // Variables
  private _jsonUrl: string = './assets/data.json';

  // Constructors
  constructor(private http: HttpClient) { }

  // Methods
  getArticles(): Observable<Article[]> {
    return this.http.get<Article[]>(this._jsonUrl);      
  }

}

article.component.ts

import { Component, OnInit } from '@angular/core';
import { ArticleService } from '../article.service';
import { Article } from '../article';

@Component({
  selector: 'app-article',
  templateUrl: './article.component.html',
  styleUrls: ['./article.component.scss']
})
export class ArticleComponent implements OnInit {

  // Variables
  public jsonArticles = [];
  public errorMsg;
  // Consturctors
  constructor(private _articleService: ArticleService) { }

  // Methods
  ngOnInit(){
    this._articleService.getArticles()
      .subscribe( 
        data => this.jsonArticles = data,
        error => this.errorMsg = error);
  }
}

文章.ts

export interface Article {
    id: number;
    author: string;
    title: string;
    content: string;
    tags: string[];
    categories: string[];
    publishDate: string;
    published: boolean;
}

data.json

 [
    {
        "id": 3,
        "author": "",
        "title": "Fancy Meat",
        "content": "Strip steak bresaola capicola tail cow chicken corned beef turkey.",
        "tags": ["test", "lorum"],
        "categories": ["blah"],
        "publishDate": "2018-02-12T08:15:00.000-05:00",
        "published": true
    },
]

为简洁起见，我截断了 json 文件，文件中有更多条目使我的 json 对象成为一个数组，并且 json 数组中最后一个条目后没有逗号。

Answer 1

我收到此错误是因为我忘记将 HttpClientModule 导入 app.module.ts 并将其声明到 imports

...
import { HttpClientModule } from '@angular/common/http';

@NgModule({
  declarations: [
    ...
  ],
  imports: [
    BrowserModule,
    FormsModule,
    AppRouteModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }