definma-ui/src/app/services/api.service.ts

import { Injectable } from '@angular/core';
import {HttpClient, HttpHeaders} from '@angular/common/http';
import {LocalStorageService} from 'angular-2-local-storage';
import {Observable} from 'rxjs';
import {ErrorComponent} from '../error/error.component';
import {ModalService} from '@inst-iot/bosch-angular-ui-components';


@Injectable({
  providedIn: 'root'
})
export class ApiService {

  private host = '/api';

  constructor(
    private http: HttpClient,
    private storage: LocalStorageService,
    private modalService: ModalService
  ) { }

  get<T>(url, f: (data?: T, err?) => void = () => {}) {
    this.requestErrorHandler<T>(this.http.get(this.host + url, this.authOptions()), f);
  }

  post<T>(url, data = null, f: (data?: T, err?) => void = () => {}) {
    this.requestErrorHandler<T>(this.http.post(this.host + url, data, this.authOptions()), f);
  }

  put<T>(url, data = null, f: (data?: T, err?) => void = () => {}) {
    this.requestErrorHandler<T>(this.http.put(this.host + url, data, this.authOptions()), f);
  }

  delete<T>(url, f: (data?: T, err?) => void = () => {}) {
    this.requestErrorHandler<T>(this.http.delete(this.host + url, this.authOptions()), f);
  }

  private requestErrorHandler<T>(observable: Observable<any>, f: (data?: T, err?) => void) {
    observable.subscribe(data => {
      f(data, undefined);
    }, err => {
      if (f.length === 2) {
        f(undefined, err);
      }
      else {
        const modalRef = this.modalService.openComponent(ErrorComponent);
        modalRef.instance.message = 'Network request failed!';
      }
    });
  }

  private authOptions() {
    const auth = this.storage.get('basicAuth');
    if (auth) {
      return {headers: new HttpHeaders({Authorization: 'Basic ' + auth})};
    }
    else {
      return {};
    }
  }
}