NestJS websocket Broadcast event to clients - websocket

Question

I'm not able to send data from server NestJS to clients via websocket. Nothing is emitted.
My use case:
several clients connected to a server via websocket
client sends a message to the server via websocket
server broadcast the message to all client
My stack:
NestJS server with websocket
Angular client and other (like chrome extension for testing websockets)
My code:
simple-web-socket.gateway.ts:
import { SubscribeMessage, WebSocketGateway, WsResponse, WebSocketServer, OnGatewayConnection, OnGatewayDisconnect, OnGatewayInit } from '#nestjs/websockets';
#WebSocketGateway({ port: 9995, transports: ['websocket'] })
export class SimpleWebSocketGateway implements OnGatewayConnection, OnGatewayDisconnect, OnGatewayInit {
#WebSocketServer() private server: any;
wsClients=[];
afterInit() {
this.server.emit('testing', { do: 'stuff' });
}
handleConnection(client: any) {
this.wsClients.push(client);
}
handleDisconnect(client) {
for (let i = 0; i < this.wsClients.length; i++) {
if (this.wsClients[i].id === client.id) {
this.wsClients.splice(i, 1);
break;
}
}
this.broadcast('disconnect',{});
}
private broadcast(event, message: any) {
const broadCastMessage = JSON.stringify(message);
for (let c of this.wsClients) {
c.emit(event, broadCastMessage);
}
}
#SubscribeMessage('my-event')
onChgEvent(client: any, payload: any) {
this.broadcast('my-event',payload);
}
}
main.ts:
import { NestFactory } from '#nestjs/core';
import { AppModule } from './app.module';
import { WsAdapter } from '#nestjs/websockets';
async function bootstrap() {
const app = await NestFactory.create(AppModule);
app.useWebSocketAdapter(new WsAdapter());
await app.listen(3000);
}
bootstrap();
app.module.ts:
import { Module } from '#nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { SimpleWebSocketGateway } from 'simple-web-socket/simple-web-socket.gateway';
#Module({
imports: [],
controllers: [AppController],
providers: [AppService, SimpleWebSocketGateway],
})
export class AppModule {}
Additionnal Informations:
Client emiting (with code line c.emit(event, broadCastMessage);) return false.
I suspect an error in the framework as my usage is quite simple. But I want to double-check with the community here if I'm doing something wrong.

Answer 1

As mentionned in the previous comment, c.send() works fine with the following snippet:
import { SubscribeMessage, WebSocketGateway, WsResponse, WebSocketServer, OnGatewayConnection, OnGatewayDisconnect, OnGatewayInit } from '#nestjs/websockets';
#WebSocketGateway({ port: 9995, transports: ['websocket'] })
export class SimpleWebSocketGateway implements OnGatewayConnection, OnGatewayDisconnect, OnGatewayInit {
#WebSocketServer() private server: any;
wsClients=[];
afterInit() {
this.server.emit('testing', { do: 'stuff' });
}
handleConnection(client: any) {
this.wsClients.push(client);
}
handleDisconnect(client) {
for (let i = 0; i < this.wsClients.length; i++) {
if (this.wsClients[i] === client) {
this.wsClients.splice(i, 1);
break;
}
}
this.broadcast('disconnect',{});
}
private broadcast(event, message: any) {
const broadCastMessage = JSON.stringify(message);
for (let c of this.wsClients) {
c.send(event, broadCastMessage);
}
}
#SubscribeMessage('my-event')
onChgEvent(client: any, payload: any) {
this.broadcast('my-event',payload);
}
}

Answer 2

I tried to broadcast a message to all connected clients using client.send():
broadcastMessage(event: string, payload: any) {
for (const client of this.clients) {
client.send(event, payload);
}
}
testBroadcast() {
this.broadcastMessage('msgInfo', { name: 'foo' });
}
the data sent ended up looking like this:
["message", "msgInfo", { "name": "foo" }]
The above did not work for me, so instead I used the client.emit() which works fine:
broadcastMessage(event: string, payload: any) {
for (const client of this.clients) {
client.emit(event, payload);
}
}
now the data looks like this:
["msgInfo", { "name": "foo" }]

Answer 3

With socket.io we could use socket.broadcast.emit()?:
#SubscribeMessage('my-event')
onChgEvent(
#MessageBody() message: any,
#ConnectedSocket() socket: Socket,
): void {
socket.broadcast.emit('my-event', message);
}