Implement HTTP AuthInterceptor

- Adds token to API requests
- Redirects to home page in case of auth failure

src/angular/planit/src/app/app.module.ts

@@ -75,6 +75,8 @@ import { SuggestedActionService } from './core/services/suggested-action.service
 import { UserService } from './core/services/user.service';
 import { WeatherEventService } from './core/services/weather-event.service';
 
+import { httpInterceptorProviders } from './core/interceptors';
+
 import {
   AccordionModule,
   AlertModule,
@@ -162,6 +164,7 @@ const AGM_CONFIG = {
   exports: [],
   schemas: [ CUSTOM_ELEMENTS_SCHEMA ],
   providers: [
+    httpInterceptorProviders,
     AccountCreateService,
     ActionCategoryService,
     ActionTypeService,

src/angular/planit/src/app/core/interceptors/AuthErrorInterceptor.ts

@@ -0,0 +1,24 @@
+import { Injectable } from '@angular/core';
+import {
+  HttpEvent, HttpInterceptor, HttpHandler, HttpRequest
+} from '@angular/common/http';
+
+import { Observable, throwError } from 'rxjs';
+import { AuthService } from '../services/auth.service';
+import { catchError } from 'rxjs/operators';
+
+/** Pass untouched request through to the next request handler. */
+@Injectable()
+export class AuthErrorInterceptor implements HttpInterceptor {
+
+  constructor(private authService: AuthService) {}
+
+  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+    return next.handle(req).pipe(catchError(err => {
+      if (err.status === 401) {
+        this.authService.logout();
+      }
+      return throwError(err);
+    }));
+  }
+}

src/angular/planit/src/app/core/interceptors/AuthInterceptor.ts

@@ -0,0 +1,22 @@
+import { Injectable } from '@angular/core';
+import {
+  HttpEvent, HttpInterceptor, HttpHandler, HttpRequest
+} from '@angular/common/http';
+
+import { Observable } from 'rxjs';
+import { AuthService } from '../services/auth.service';
+
+/** Pass untouched request through to the next request handler. */
+@Injectable()
+export class AuthInterceptor implements HttpInterceptor {
+
+  constructor(private authService: AuthService) {}
+
+  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+    const authToken = this.authService.getToken();
+    const authRequest = req.clone({ setHeaders: {
+      Authorization: `Token ${authToken}`
+    }})
+    return next.handle(authRequest);
+  }
+}

src/angular/planit/src/app/core/interceptors/index.ts

@@ -0,0 +1,9 @@
+import { HTTP_INTERCEPTORS } from '@angular/common/http';
+
+import { AuthInterceptor } from './AuthInterceptor';
+import { AuthErrorInterceptor } from './AuthErrorInterceptor';
+
+export const httpInterceptorProviders = [
+  {provide: HTTP_INTERCEPTORS, useClass: AuthInterceptor, multi: true},
+  {provide: HTTP_INTERCEPTORS, useClass: AuthErrorInterceptor, multi: true}
+];