Notify through websocket new number of notifications

src/controllers/UserWebSocketController.ts

@@ -9,6 +9,7 @@ import { RequestHandler } from '../entities/RequestHandler';
 import { time } from '../utils/DateUtils';
 import { randomStr } from '../utils/CryptUtils';
 import { EventsHelper } from '../helpers/EventsHelper';
+import { NotificationsHelper } from '../helpers/NotificationsHelper';
 
 interface PendingRequests {
 	time: number,
@@ -18,11 +19,18 @@ interface PendingRequests {
 }
 
 interface ActiveClient {
+	socketID: string,
 	clientID: number,
 	userID: number,
 	ws: ws
 }
 
+interface WsMessage {
+	id: string,
+	title: string,
+	data: any
+}
+
 // Tokens are valid only 10 seconds after they are generated
 const TOKENS_DURATION = 10
 const TOKEN_LENGTH = 20
@@ -105,6 +113,7 @@ export class UserWebSocketController {
 
 		// Add the client to the list of active clients
 		const client: ActiveClient = {
+			socketID: randomStr(30),
 			clientID: entry.clientID,
 			userID: entry.userID,
 			ws: ws
@@ -150,7 +159,59 @@ export class UserWebSocketController {
 		for(const entry of this.active_clients.filter((f) => f.clientID == clientID && f.userID == userID))
 			entry.ws.close();
 	}
+
+	/**
+	 * Send a message to a socket
+	 * 
+	 * @param userID Target user ID
+	 * @param socketID Target socket ID (if null the message is sent to 
+	 * all the active sockets of the user)
+	 * @param message The message to send
+	 */
+	public static Send(userID: number, socketID: string, message: WsMessage) {
+		for(const entry of this.active_clients.filter(
+			(e) => e.userID == userID
+				&& (socketID.length == 0 || e.socketID == socketID)))
+		{
+			if(entry.ws.readyState == ws.OPEN)
+				entry.ws.send(JSON.stringify(message));
+		}
+	}
+
+	/**
+	 * Check out whether a user has an active websocket or not
+	 * 
+	 * @param userID Target user ID
+	 */
+	public static IsConnected(userID: number) : boolean {
+		return this.active_clients.find((e) => e.userID == userID) != undefined;
+	}
+
+	/**
+	 * Send updated notifications number to some users
+	 * 
+	 * @param usersID Target users ID
+	 */
+	public static async SendNewNotificationsNumber(usersID: number[]) {
+
+		// Process each user
+		for(const userID of usersID) {
+			if(!this.IsConnected(userID))
+				continue;
+
+			// Notify user
+			this.Send(userID, "", {
+				title: "number_notifs",
+				id: "",
+				data: await NotificationsHelper.CountUnread(userID)
+			});
+		}
+
+	}
 }
 
 // When user sign out
-EventsHelper.Listen("destroyed_login_tokens", (e) => UserWebSocketController.CloseClientSockets(e.client.id, e.userID));
+EventsHelper.Listen("destroyed_login_tokens", (e) => UserWebSocketController.CloseClientSockets(e.client.id, e.userID));
+
+// When we get a new number of notifications
+EventsHelper.Listen("updated_number_notifications", async (e) => await UserWebSocketController.SendNewNotificationsNumber(e.usersID));

src/helpers/EventsHelper.ts

@@ -13,11 +13,17 @@ export interface DestroyedLoginTokensEvent {
 	client: APIClient
 }
 
+// When some user might have an updated number of notifications
+export interface UpdatedNotificationsNumberEvent {
+	usersID: number[]
+}
+
 /**
  * Global map of all possible events
  */
 export interface EventsMap {
-	"destroyed_login_tokens": DestroyedLoginTokensEvent
+	"destroyed_login_tokens": DestroyedLoginTokensEvent,
+	"updated_number_notifications": UpdatedNotificationsNumberEvent,
 }
 
 export class EventsHelper {

src/helpers/NotificationsHelper.ts

@@ -6,6 +6,7 @@ import { PostPageKind, PostVisibilityLevel } from "../entities/Post";
 import { FriendsHelper } from "./FriendsHelper";
 import { GroupsHelper } from "./GroupsHelper";
 import { GroupMembershipLevels } from "../entities/GroupMember";
+import { EventsHelper } from "./EventsHelper";
 
 /**
  * Notifications helper
@@ -308,6 +309,9 @@ export class NotificationsHelper {
 			NOTIFICATIONS_TABLE, 
 			this.NotifToDB(n, true)
 		)
+
+		// Trigger notify system
+		await EventsHelper.Emit("updated_number_notifications", {usersID: [n.destUserID]});
 	}
 
 	/**