Angular 中的地址搜索栏，可观察到带有推荐的 URL答案

【问题标题】：Address Search Bar in Angular with Observable to url with recommendationsAngular 中的地址搜索栏，可观察到带有推荐的 URL
【发布时间】：2020-07-22 12:51:17
【问题描述】：

export class AddressSuggestionsService {
  private addressSuggestionsUrl =
    'http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?f=json&singleLine=';

  constructor(private httpClient: HttpClient) {}

  getAddressSuggestions(term: string): Observable<any> {
    return this.httpClient
      .get(
        `${this.addressSuggestionsUrl}${term}&outfields=Match_addr,Addr_type=PointAddress`
      )
      .pipe(
        tap((data) => console.log('All: ' + JSON.stringify(data))),
        catchError(this.handleError)
      );
  }
}

我正在为 Angular 中的地址建议构建一个自动完成的搜索栏。地址建议来自 URL 中的第三方提供商。我无法从 Observable 响应中提取某个键。该键名为Candidates。是否可以从服务中的可观察响应中仅提取密钥？ github repo

【问题讨论】：

标签： angular service autocomplete rxjs esri

【解决方案1】：

使用地图运算符将响应转换为其他内容。

为您的回复创建类型是个好主意。它会让你在 vs code 中完成代码更容易。


interface AddressSuggestionResponse {
  Candidates: string[]
}

export class AddressSuggestionsService {
  private addressSuggestionsUrl =
    'http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?f=json&singleLine=';

  constructor(private httpClient: HttpClient) {}

  getAddressSuggestions(term: string): Observable<string[]> {
    return this.httpClient
      .get<AddressSuggestionResponse>(
        `${this.addressSuggestionsUrl}${term}&outfields=Match_addr,Addr_type=PointAddress`
      )
      .pipe(
        map((data) => data.Candidates),
        catchError(this.handleError)
      );
  }
}

【讨论】：

就是这样！下面的最终解决方案

【解决方案2】：

  searchAddress(term: string): Observable<Address[]> {
    let url = `${this.endpoint}${term}&maxLocations=5&location=30.270,-97.745&distance=80467.2`;

    if (!term.trim()) {
      return of([]);
    }
    return this.httpClient
      .get<Address[]>(url)
      .pipe(
        map((data) => data['candidates']),
          catchError(this.handleError<Address[]>('addresses', []))
        );
  }
  private handleError<T>(operation = 'operation', result?: T) {
    return (error: any): Observable<T> => {
      console.log(`failed: ${error.message}`);
      return of(result as T);
    };
  }
}

【讨论】：