Conn state listener, click action button

web/src/app/ConnectionManager.js

@@ -3,10 +3,36 @@ import {sha256} from "./utils";
 
 class ConnectionManager {
     constructor() {
+        console.log(`connection manager`)
         this.connections = new Map(); // ConnectionId -> Connection (hash, see below)
+        this.stateListener = null; // Fired when connection state changes
+        this.notificationListener = null; // Fired when new notifications arrive
     }
 
-    async refresh(subscriptions, users, onNotification) {
+    registerStateListener(listener) {
+        this.stateListener = listener;
+    }
+
+    resetStateListener() {
+        this.stateListener = null;
+    }
+
+    registerNotificationListener(listener) {
+        this.notificationListener = listener;
+    }
+
+    resetNotificationListener() {
+        this.notificationListener = null;
+    }
+
+    /**
+     * This function figures out which websocket connections should be running by comparing the
+     * current state of the world (connections) with the target state (targetIds).
+     *
+     * It uses a "connectionId", which is sha256($subscriptionId|$username|$password) to identify
+     * connections. If any of them change, the connection is closed/replaced.
+     */
+    async refresh(subscriptions, users) {
         if (!subscriptions || !users) {
             return;
         }
@@ -17,10 +43,9 @@ class ConnectionManager {
                 const connectionId = await makeConnectionId(s, user);
                 return {...s, user, connectionId};
             }));
-        const activeIds = subscriptionsWithUsersAndConnectionId.map(s => s.connectionId);
-        const deletedIds = Array.from(this.connections.keys()).filter(id => !activeIds.includes(id));
+        const targetIds = subscriptionsWithUsersAndConnectionId.map(s => s.connectionId);
+        const deletedIds = Array.from(this.connections.keys()).filter(id => !targetIds.includes(id));
 
-        console.log(subscriptionsWithUsersAndConnectionId);
         // Create and add new connections
         subscriptionsWithUsersAndConnectionId.forEach(subscription => {
             const subscriptionId = subscription.id;
@@ -31,7 +56,16 @@ class ConnectionManager {
                 const topic = subscription.topic;
                 const user = subscription.user;
                 const since = subscription.last;
-                const connection = new Connection(connectionId, subscriptionId, baseUrl, topic, user, since, onNotification);
+                const connection = new Connection(
+                    connectionId,
+                    subscriptionId,
+                    baseUrl,
+                    topic,
+                    user,
+                    since,
+                    (subscriptionId, notification) => this.notificationReceived(subscriptionId, notification),
+                    (subscriptionId, state) => this.stateChanged(subscriptionId, state)
+                );
                 this.connections.set(connectionId, connection);
                 console.log(`[ConnectionManager] Starting new connection ${connectionId} (subscription ${subscriptionId} with user ${user ? user.username : "anonymous"})`);
                 connection.start();
@@ -46,6 +80,18 @@ class ConnectionManager {
             connection.close();
         });
     }
+
+    stateChanged(subscriptionId, state) {
+        if (this.stateListener) {
+            this.stateListener(subscriptionId, state);
+        }
+    }
+
+    notificationReceived(subscriptionId, notification) {
+        if (this.notificationListener) {
+            this.notificationListener(subscriptionId, notification);
+        }
+    }
 }
 
 const makeConnectionId = async (subscription, user) => {