WIP: Implement frontend

frontend/src/app/interceptor/api-url.interceptor.ts

@@ -0,0 +1,18 @@
+import { Injectable } from '@angular/core';
+import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { Config } from '../config/Config';
+
+@Injectable()
+export class ApiUrlInterceptor implements HttpInterceptor {
+
+  constructor() {
+  }
+
+  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+    request = request.clone({
+      url: Config.apiBasePath + request.url
+    });
+    return next.handle(request);
+  }
+}

frontend/src/app/interceptor/error.interceptor.ts

@@ -0,0 +1,39 @@
+import { Injectable } from '@angular/core';
+import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
+import { Observable, throwError } from 'rxjs';
+import { catchError } from 'rxjs/operators';
+import { ApiErrorResponse } from '../models/dtos/ApiErrorResponse';
+import { DialogService } from '../services/dialog.service';
+
+@Injectable()
+export class ErrorInterceptor implements HttpInterceptor {
+  constructor(private dialogService: DialogService) {
+  }
+
+  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+    return next.handle(request).pipe(catchError((err: ApiErrorResponse) => {
+      switch (err.status) {
+        case 400:
+          if (err.error.message === 'Validation error') {
+            this.dialogService.showErrorDialog(JSON.stringify(err.error.errors));
+          } else {
+            this.dialogService.showErrorDialog(err.error.message);
+          }
+          break;
+        case 401:
+          this.dialogService.showErrorDialog(err.error.message);
+          break;
+        case 409:
+        case 500:
+          this.dialogService.showErrorDialog(err.error.message);
+          break;
+        case 503:
+        case 504:
+          this.dialogService.showErrorDialog('Can\'t reach the backend at the moment.\n' +
+            'Please ensure that the backend is running and try again');
+          break;
+      }
+      return throwError(err);
+    }));
+  }
+}