refresh token for api requests (401)

dmp-frontend/src/common/http/interceptors/unauthorized-response.interceptor.ts

@@ -1,8 +1,8 @@
 import { HttpErrorResponse, HttpHandler, HttpHeaderResponse, HttpProgressEvent, HttpRequest, HttpResponse, HttpSentEvent, HttpUserEvent } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { Router } from '@angular/router';
-import { Observable, throwError } from 'rxjs';
-import { catchError, mergeMap, tap } from 'rxjs/operators';
+import { Observable, from, throwError } from 'rxjs';
+import { catchError, filter, mergeMap, tap } from 'rxjs/operators';
 import { AuthService } from '../../../app/core/services/auth/auth.service';
 import { BaseInterceptor } from './base.interceptor';
 import { InterceptorType } from './interceptor-type';
@@ -19,14 +19,15 @@ export class UnauthorizedResponseInterceptor extends BaseInterceptor {
 
 	get type(): InterceptorType { return InterceptorType.UnauthorizedResponse; }
 
+	private accountRefresh$: Observable<boolean> = null;
+
 	interceptRequest(req: HttpRequest<any>, next: HttpHandler): Observable<HttpSentEvent | HttpHeaderResponse | HttpProgressEvent | HttpResponse<any> | HttpUserEvent<any>> {
 		return next.handle(req).pipe(
 			catchError(error => {
 				if (error instanceof HttpErrorResponse) {
 					switch ((<HttpErrorResponse>error).status) {
 						case 401:
-							this.logoutUser();
-							return throwError(error);
+							return this.handle401Error(req, next);
 						default:
 							return throwError(error);
 					}
@@ -36,6 +37,33 @@ export class UnauthorizedResponseInterceptor extends BaseInterceptor {
 			}));
 	}
 
+	private handle401Error(req: HttpRequest<any>, next: HttpHandler) {
+		if (!this.accountRefresh$) {
+			this.accountRefresh$ = from(
+				this.authService.refreshToken().then((isRefreshed) => {
+					this.accountRefresh$ = null;
+					if (!isRefreshed) {
+						this.logoutUser();
+						return false;
+					}
+
+					return true;
+				})
+			).pipe(filter((x) => x));
+		}
+		return this.accountRefresh$.pipe(mergeMap(account => this.repeatRequest(req, next)));
+	}
+
+	private repeatRequest(originalRequest: HttpRequest<any>, next: HttpHandler) {
+		const newAuthenticationToken: String = this.authService.currentAuthenticationToken();
+		const newRequest = originalRequest.clone({
+			setHeaders: {
+				Authorization: `Bearer ${newAuthenticationToken}`
+			}
+		});
+		return next.handle(newRequest);
+	}
+
 	private logoutUser() {
 		//this.authService.clear();
 		if (!this.isLoginRoute() && !this.isSignupRoute()) { this.router.navigate(['/unauthorized']); }