gae/frontend/src/app/shared/servicebase.ts

/**
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { HttpClient, HttpErrorResponse, HttpParams, HttpResponse } from '@angular/common/http';
import { Observable, throwError } from 'rxjs';

export class ServiceBase {
  url: string;
  protected constructor(public httpClient: HttpClient) {
  }
  protected handleError(error: HttpErrorResponse) {
    if (error.error instanceof ErrorEvent) {
      // A client-side or network error occurred. Handle it accordingly.
      console.error('An error occurred:', error.error.message);
    } else {
      // The backend returned an unsuccessful response code.
      // The response body may contain clues as to what went wrong,
      console.error(
        `Backend returned code ${error.status}, ` +
        `body was: ${error.error}`);
    }
    // return an observable with a user-facing error message
    return throwError(error);
  }
  public getCount(filterInfo: string): Observable<number> {
    const url = this.url + 'count';
    return this.httpClient.post<number>(url, {filter: filterInfo});
  }
}