Function realtimeSetSubscriptions

apis/realtime.go:184–249

note: in case of reconnect, clients will have to resubmit all subscriptions again

(e *core.RequestEvent)

// note: in case of reconnect, clients will have to resubmit all subscriptions again
func realtimeSetSubscriptions(e *core.RequestEvent) error {
	form := new(realtimeSubscribeForm)

	err := e.BindBody(form)
	if err != nil {
		return e.BadRequestError("", err)
	}

	err = form.validate()
	if err != nil {
		return e.BadRequestError("", err)
	}

	// find subscription client
	client, err := e.App.SubscriptionsBroker().ClientById(form.ClientId)
	if err != nil {
		return e.NotFoundError("Missing or invalid client id.", err)
	}

	// for just in case to prevent someone changing a guest subscription
	//
	// note1: this is an extra precaution against clientId bruteforce attempts
	// for installations allowing longer realtime connections duration
	//
	// note2: custom registered clients (aka. those without IP in the store)
	// are excluded from the check for backward compatibility
	clientIP, _ := client.Get(RealtimeClientIPKey).(string)
	if clientIP != "" && clientIP != e.RealIP() {
		return e.BadRequestError(
			"Invalid realtime client.",
			errors.New("the subscription request IP doesn't match with the realtime client IP"),
		)
	}

	// for now allow only guest->auth upgrades and any other auth change is forbidden
	clientAuth, _ := client.Get(RealtimeClientAuthKey).(*core.Record)
	if clientAuth != nil && !isSameAuth(clientAuth, e.Auth) {
		return e.ForbiddenError("The current and the previous request authorization don't match.", nil)
	}

	event := new(core.RealtimeSubscribeRequestEvent)
	event.RequestEvent = e
	event.Client = client
	event.Subscriptions = form.Subscriptions

	return e.App.OnRealtimeSubscribeRequest().Trigger(event, func(e *core.RealtimeSubscribeRequestEvent) error {
		// update auth state
		e.Client.Set(RealtimeClientAuthKey, e.Auth)

		// unsubscribe from any previous existing subscriptions
		e.Client.Unsubscribe()

		// subscribe to the new subscriptions
		e.Client.Subscribe(e.Subscriptions...)

		e.App.Logger().Debug(
			"Realtime subscriptions updated",
			slog.String("clientId", e.Client.Id()),