如何在角度 4 中执行搜索功能？

Question

如标题中所述，我想在角度 4 中执行 search 函数。我在 SpringBoot 后端有 REST 服务，我在 Postman 中调用了它，它工作得很好，但在前端没有角度的。

我的代码在Service.TS

@Injectable()
export class EvenementService {

  private evensUrl_del = 'http://localhost:8080/evenement';
  private headers = new Headers({ 'Content-Type': 'application/json' });
  private options = new RequestOptions({ headers: this.headers });

  constructor(private http: Http) { }

  // Get all events
  getEvenement(): Promise<Evenement[]> {
    return this.http.get(this.evensUrl)
      .toPromise()
      .then(response => response.json() as Evenement[])
      .catch(this.handleError);
  }

  getEvenementByType(typeE: string): Promise<Evenement[]> {
return this.http.get(this.evensUrl_del + '/evenements/' + typeE, this.options)
  .toPromise()
  .then(response => response.json() as Evenement)
  .catch(this.handleError);

} }

我的Component.TS

@Component({
  selector: 'app-evenement',
  templateUrl: './evenement.component.html',
  styleUrls: ['./evenement.component.css']
})
export class EvenementComponent implements OnInit {
  events: Evenement = new Evenement();
  evenmt: Evenement[];
  //e: Evenement[];

  typeE: string;

  constructor(public router: Router, private modalService: NgbModal, private evenementService: EvenementService, private toastyService: ToastyService) { }

  ngOnInit(): void {
    this.typeE="";
    //this.getEvenements();
  }

  ver(events: Evenement, modal) {
    evenmt => this.evenmt = evenmt;
    this.modalService.open(modal, { size: 'lg' });
  }

  searchEvenement(){
    this.evenementService.getEvenementByType(this.typeE).then(evenmt => this.evenmt = evenmt);
  }

  getEvenements() {
    this.evenementService.getEvenement().then(evenmt => this.evenmt = evenmt);
  }
}

终于component.html

<div style="width: 300px;">
            <div class="form-group">
                <label for="typeE"><b>Type</b></label>
                <input type="text" class="form-control" id="typeE" name="typeE" [(ngModel)]="typeE" required>
            </div>

            <div class="btn-group">
                <button type="button" class="btn btn-success" (click)="searchEvenement()">Rechercher</button>
            </div>
    </div>
    <ul>
        <li *ngFor="let e of evenmt">
            <h4>{{e.typeE}} - {{e.prixE}} {{e.dateE}}</h4>
        </li>
    </ul>

使用上面的代码，当我在浏览器中点击搜索按钮时，它会返回以下错误：

ERROR 错误：未捕获（承诺中）：响应状态：302 OK for URL：http://localhost:8080/evenement/evenements/degustation 尽管在 Eclipse 终端中，我查找的行已显示。所以我认为问题实际上出在 Angular 中，但我不知道具体在哪里。

有人可以帮我解决这个问题吗？谢谢

Answer 1

无需承诺您可以将代码修改为：

服务

@Injectable()
export class EvenementService {

    private evensUrl_del = 'http://localhost:8080/evenement';
    private headers = new Headers({ 'Content-Type': 'application/json' });
    private options = new RequestOptions({ headers: this.headers });

    constructor(private http: Http) { }

    // Get all events
    getEvenement(): Promise<Evenement[]> {
        return this.http.get(this.evensUrl)
                    .map(res => res.json())
                    .catch((err) => this.handleError(err));
    }

    getEvenementByType(typeE: string): Promise<Evenement[]> {
        return this.http.get(`${this.evensUrl_del}/evenements/${typeE}`, this.options)
                        .map(res => res.json())
                        .catch((err) => this.handleError(err));
    } 
}

组件

searchEvenement(){
    this.evenementService.getEvenementByType(this.typeE).subscribe(evenmt => {
        setTimeout(() => { <====== You can use timeout
            this.evenmt = evenmt;
        });
    });
}

getEvenements() {
    this.evenementService.getEvenement().subscribe(evenmt => this.evenmt = evenmt);
}