- add DatasetApiService wit HttpService

- Interfaces for stations and phenomena

src/app/services/dataset-api.service.ts

@@ -0,0 +1,63 @@
+// https://github.com/52North/helgoland-toolbox/blob/develop/libs/core/src/lib/dataset-api/dataset-impl-api-interface.service.ts
+// https://github.com/52North/helgoland-toolbox/blob/495f75cadcc3e7232206db1cd5dd8bbf3a172c4b/libs/core/src/lib/abstract-services/api-interface.ts#L6
+// https://github.com/52North/helgoland-toolbox/blob/495f75cadcc3e7232206db1cd5dd8bbf3a172c4b/libs/core/src/lib/api-communication/connectors/dataset-api-v3-connector/api-v3-interface.ts#L321
+import { Injectable } from '@angular/core';
+import { HttpClient, HttpHeaders  } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { Phenomenon } from '../../shared/models/phenomenon';
+import { Station } from '../../shared/models/station';
+
+import { HttpService } from './http.service';
+import { HttpRequestOptions } from '../../shared/models/http-requests';
+import { HttpParams } from '@angular/common/http';
+
+
+// @Injectable({
+//   providedIn: 'root'
+// })
+
+@Injectable()
+export class DatasetApiService {
+
+    // constructor() { }
+    constructor(
+        private httpClient: HttpClient,
+        protected httpService: HttpService,) {
+    }
+
+    public getPhenomena(apiUrl: string, params?, options?) {
+        const url = this.createRequestUrl(apiUrl, 'phenomena');        
+        return this.requestApi<Phenomenon[]>(url, params, options);
+    }
+
+    public getStations(apiUrl: string, params?, options?: HttpRequestOptions): Observable<Station[]> {
+        const url = this.createRequestUrl(apiUrl, 'features');
+        return this.requestApi<Station[]>(url, params, options);
+    }
+
+
+    protected createRequestUrl(apiUrl: string, endpoint: string, id?: string) {
+        // TODO Check whether apiUrl ends with slash
+        let requestUrl = apiUrl + endpoint;
+        if (id) { requestUrl += '/' + id; }
+        return requestUrl;
+    }
+
+    protected requestApi<T>(
+        url: string, params: HttpParams = new HttpParams(), options: HttpRequestOptions = {}
+    ): Observable<T> {
+        return this.httpService.client(options).get<T>(url,
+            {
+                params,
+                headers: this.createBasicAuthHeader(options.basicAuthToken)
+            }
+        );
+    }
+
+    protected createBasicAuthHeader(token: string): HttpHeaders {
+        const headers = new HttpHeaders();
+        if (token) { return headers.set('Authorization', token); }
+        return headers;
+    }
+
+}

src/app/services/http.service.ts

@@ -0,0 +1,45 @@
+// https://github.com/52North/helgoland-toolbox/blob/495f75cadcc3e7232206db1cd5dd8bbf3a172c4b/libs/core/src/lib/dataset-api/http.service.ts#L37
+import { Injectable } from '@angular/core';
+import { HttpClient, HttpEvent, HttpHandler, HttpRequest } from '@angular/common/http';
+import { Inject, InjectionToken, Optional } from '@angular/core';
+import { Observable } from 'rxjs';
+
+import { HttpRequestOptions } from '../../shared/models/http-requests';
+
+export const HTTP_SERVICE_INTERCEPTORS = new InjectionToken<HttpServiceInterceptor>('HTTP_SERVICE_INTERCEPTORS');
+
+export interface HttpServiceHandler {
+    handle(req: HttpRequest<any>, options: Partial<HttpRequestOptions>): Observable<HttpEvent<any>>;
+}
+
+export interface HttpServiceInterceptor {
+    intercept(req: HttpRequest<any>, options: Partial<HttpRequestOptions>, next: HttpServiceHandler): Observable<HttpEvent<any>>;
+}
+
+
+@Injectable()
+export class HttpService {
+
+    private handler: HttpServiceHandler;
+
+    constructor(
+        protected httpHandler: HttpHandler,
+        @Optional() @Inject(HTTP_SERVICE_INTERCEPTORS) interceptors: HttpServiceInterceptor[] | null
+    ) {
+        let handler: HttpServiceHandler = {
+            handle: (req, options) => httpHandler.handle(req)
+        };
+        if (interceptors) {
+            handler = interceptors.reduceRight((next, interceptor) => ({
+                handle: (req, options) => interceptor.intercept(req, options, next)
+            }), handler);
+        }
+        this.handler = handler;
+    }
+
+    public client(options: HttpRequestOptions = {}): HttpClient {
+        return new HttpClient({
+            handle: (req) => this.handler.handle(req, options)
+        });
+    }
+}