x.websocket: server broadcast plus examples (#7922)

examples/x/websocket/client-server/server.v

@@ -0,0 +1,48 @@
+module main
+
+import os
+import x.websocket
+import term
+
+// this server accepts client connections and broadcast all messages to other connected clients
+fn main() {
+	go start_server()
+	println('press enter to quit...')
+	os.get_line()
+}
+
+fn start_server() ? {
+	mut s := websocket.new_server(30000, '')
+	// Make that in execution test time give time to execute at least one time
+	s.ping_interval = 100
+	s.on_connect(fn (mut s websocket.ServerClient) ?bool {
+		// Here you can look att the client info and accept or not accept
+		// just returning a true/false
+		if s.resource_name != '/' {
+			return false
+		}
+		return true
+	})?
+	
+	// on_message_ref, broadcast all incoming messages to all clients except the one sent it
+	s.on_message_ref(fn (mut ws websocket.Client, msg &websocket.Message, mut m websocket.Server) ? {
+		for _, cli in m.clients {
+			mut c := cli
+			if c.client.state == .open && c.client.id !=  ws.id {
+				c.client.write(msg.payload, websocket.OPCode.text_frame) or {
+					panic(err)
+				}
+			}
+		}
+	}, s)
+
+	s.on_close(fn (mut ws websocket.Client, code int, reason string) ? {
+		println(term.green('client ($ws.id) closed connection'))
+	})
+	s.listen() or {
+		println(term.red('error on server listen: $err'))
+	}
+	unsafe {
+		s.free()
+	}
+}