Remove user when they leave the map

functions/src/index.ts

@@ -1,10 +1,15 @@
+import * as admin from "firebase-admin";
 import * as functions from 'firebase-functions';
-import * as cor from 'cors';
 
-const cors = cor({origin: true});
+const cors = require('cors')({origin: true});
 
-exports.helloWorld = functions.https.onRequest((req, res) => {
-    return cors(req, res, () => {
-        res.status(200).send('Hello World!');
+admin.initializeApp();
+const db = admin.firestore();
+
+exports.closeSession = functions.https.onRequest((req, resp) => {
+    return cors(req, resp, () => {
+        const code = req.query.mapCode;
+        const username = req.query.username;
+        return db.collection('Maps').doc(code).collection('Users').doc(username).delete();
     });
 });

src/app/services/sync.service.ts

@@ -4,7 +4,6 @@ import {BehaviorSubject, combineLatest, Subscription} from "rxjs";
 import {Circle, MapData, MapSymbol, Marker, Measurement, Polygon, Polyline, Position, Rectangle} from "../models/mapSymbol";
 import * as _ from 'lodash';
 import {map} from "rxjs/operators";
-import * as firebase from "firebase";
 
 export const LOCATION_COLLECTION = 'Users';
 export const MAP_COLLECTION = 'Maps';
@@ -16,14 +15,18 @@ export class SyncService {
     private location;
     private locationChanged = false;
     private locationDoc: AngularFirestoreDocument;
+    private mapCode: string;
     private mapDoc: AngularFirestoreDocument;
     private mapChanged = false;
     private mapSub: Subscription;
     private saveInterval: number;
+    private username: string;
 
     mapData = new BehaviorSubject<MapData>({});
 
-    constructor(private db: AngularFirestore) { }
+    constructor(private db: AngularFirestore) {
+        window.addEventListener('beforeunload', () => this.unload());
+    }
 
     private addMapSymbol(s: MapSymbol, key: string) {
         s.new = true;
@@ -80,9 +83,10 @@ export class SyncService {
     }
 
     load(mapCode: string, username: string) {
+        this.mapCode = mapCode;
+        this.username = username;
         this.mapDoc = this.db.collection(MAP_COLLECTION).doc(mapCode);
         this.locationDoc = this.mapDoc.collection(LOCATION_COLLECTION).doc(username);
-        firebase.database().ref(`${MAP_COLLECTION}/mapCode/${LOCATION_COLLECTION}/username`).onDisconnect().remove();
 
         this.mapSub = combineLatest(this.mapDoc.valueChanges(), this.mapDoc.collection(LOCATION_COLLECTION).snapshotChanges())
             .pipe(map(data => {
@@ -131,8 +135,8 @@ export class SyncService {
     }
 
     async unload() {
+        this.save();
         if(this.saveInterval) clearInterval(this.saveInterval);
-        this.mapData.next({});
 
         if(this.mapSub) {
             this.mapSub.unsubscribe();
@@ -148,6 +152,11 @@ export class SyncService {
             this.location = null;
             this.locationChanged = false;
             this.locationDoc = null;
-        }
+            navigator.sendBeacon(`https://us-central1-mapalliance-ab38a.cloudfunctions.net/closeSession/?mapCode=${this.mapCode}&username=${this.username}`);
+        }
+
+        this.mapCode = null;
+        this.username = null;
+        this.mapData.next({});
     }
 }