subscribe to user in chat service

angularfire-start/src/app/services/chat.service.ts

@@ -9,7 +9,7 @@ import {
   getAuth,
   User,
 } from '@angular/fire/auth';
-import { map, switchMap, firstValueFrom, filter, Observable } from 'rxjs';
+import { map, switchMap, firstValueFrom, filter, Observable, Subscription } from 'rxjs';
 import {
   doc,
   docData,
@@ -29,6 +29,7 @@ import {
   limit,
   onSnapshot,
   DocumentData,
+  FieldValue,
 } from '@angular/fire/firestore';
 import {
   Storage,
@@ -39,6 +40,16 @@ import {
 import { getToken, Messaging, onMessage } from '@angular/fire/messaging';
 import { Router } from '@angular/router';
 
+type ChatMessage = {
+  name: string | null,
+  profilePicUrl: string | null,
+  timestamp: FieldValue,
+  uid: string | null,
+  text?: string,
+  imageUrl?: string
+};
+
+
 @Injectable({
   providedIn: 'root',
 })
@@ -51,8 +62,16 @@ export class ChatService {
   private provider = new GoogleAuthProvider();
   LOADING_IMAGE_URL = 'https://www.google.com/images/spin-32.gif?a';
 
-  // Observable user
+  // observable that is updated when the auth state changes
   user$ = user(this.auth);
+  currentUser: User | null = this.auth.currentUser;
+  userSubscription: Subscription;
+
+  constructor() {
+    this.userSubscription = this.user$.subscribe((aUser: User | null) => {
+        this.currentUser = aUser;
+    });
+  }
 
   // Login Friendly Chat.
   login() {}