From 1488f8ef00d3ca61c7cd4b8a28d644a8fad35c64 Mon Sep 17 00:00:00 2001
From: "k.triantafyllou" <k.triantafyllou@di.uoa.gr>
Date: Fri, 5 Nov 2021 17:22:41 +0200
Subject: [PATCH] Add AdvancedAsyncSubject in order to avoid duplicate code to
 be executed  while userInfo has been called

---
 services/user-management.service.ts | 10 +++---
 utils/AdvancedAsyncSubject.ts       | 50 +++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100644 utils/AdvancedAsyncSubject.ts

diff --git a/services/user-management.service.ts b/services/user-management.service.ts
index d936409d..a19e85cb 100644
--- a/services/user-management.service.ts
+++ b/services/user-management.service.ts
@@ -1,19 +1,20 @@
 import {Injectable} from '@angular/core';
 import {HttpClient} from '@angular/common/http';
-import {BehaviorSubject, from, Observable, of} from "rxjs";
+import {from, Observable} from "rxjs";
 import {COOKIE, Session, User} from "../login/utils/helper.class";
 import {map} from "rxjs/operators";
 import {NavigationEnd, Router} from "@angular/router";
 import {properties} from "../../../environments/environment";
 import {StringUtils} from "../utils/string-utils.class";
 import {CustomOptions} from "./servicesUtils/customOptions.class";
+import {AdvancedAsyncSubject} from "../utils/AdvancedAsyncSubject";
 
 @Injectable({
   providedIn: 'root'
 })
 export class UserManagementService {
   
-  private getUserInfoSubject: BehaviorSubject<User> = new BehaviorSubject<User>(null);
+  private getUserInfoSubject: AdvancedAsyncSubject<User> = new AdvancedAsyncSubject<User>();
   public fixRedirectURL: string = null;
   private redirectUrl: string = null;
   private readonly promise: Promise<User>;
@@ -53,9 +54,8 @@ export class UserManagementService {
   }
   
   public updateUserInfo(resolve: Function = null) {
-    /** @deprecated **/
     const token = COOKIE.getCookie('AccessToken');
-    if (!token && properties.userInfoUrl.includes("accessToken")) {
+    if (!token) {
       this.getUserInfoSubject.next(null);
       if (resolve) {
         resolve();
@@ -70,7 +70,7 @@ export class UserManagementService {
           resolve();
         }
       }, error => {
-        if(this.getUserInfoSubject.value) {
+        if(this.getUserInfoSubject.getValue()) {
           this.getUserInfoSubject.next(null);
         }
         if (resolve) {
diff --git a/utils/AdvancedAsyncSubject.ts b/utils/AdvancedAsyncSubject.ts
new file mode 100644
index 00000000..e3c657b6
--- /dev/null
+++ b/utils/AdvancedAsyncSubject.ts
@@ -0,0 +1,50 @@
+import {Subject, Subscriber, Subscription} from "rxjs";
+
+export class AdvancedAsyncSubject<T> extends Subject<T>{
+  private _value: T = null;
+  private hasNext: boolean = false;
+  private hasFinished: boolean = false;
+  
+  /** @deprecated This is an internal implementation detail, do not use. */
+  _subscribe(subscriber: Subscriber<any>): Subscription {
+    if (this.hasError) {
+      subscriber.error(this.thrownError);
+      return Subscription.EMPTY;
+    } else if (this.hasFinished && this.hasNext) {
+      subscriber.next(this._value);
+    }
+    return super._subscribe(subscriber);
+  }
+  
+  next(value: T): void {
+    if (!this.hasFinished) {
+      this._value = value;
+      this.hasNext = true;
+      this.finish();
+    } else {
+      this._value = value;
+      super.next(value);
+    }
+  }
+  
+  get value() {
+    return this.getValue();
+  }
+  
+  getValue() {
+    return this._value;
+  }
+  
+  error(error: any): void {
+    if (!this.hasFinished) {
+      super.error(error);
+    }
+  }
+  
+  finish(): void {
+    this.hasFinished = true;
+    if (this.hasNext) {
+      super.next(this._value);
+    }
+  }
+}