func (mb *MQTT_1) eventHandler(ctxPath string, wos *server.WotServer) func(mqtt.Client, mqtt.Message) {
return func(client mqtt.Client, m mqtt.Message) {
topic := m.Topic()
p := PropertyChange{
Name: topic[len(ctxPath)+1 : len(topic)],
Value: string(m.Payload()),
}
mb.values[topic] = p.Value
wos.EmitEvent("property-change", p)
}
}
//Implementation of interaction with Web Device
func setupWotServer(s *server.WotServer) {
s.OnGetProperty("relay", func() interface{} {
log.Info("OnGetProperty: relay")
return db["relay"]
}).OnUpdateProperty("relay", func(newValue interface{}) {
log.Info("OnUpdateProperty: relay")
db["relay"] = newValue
}).OnInvokeAction("throtle-move", func(args interface{}, ph async.ProgressHandler) interface{} {
log.Info("OnInvokeAction: throtle-move, position: ", args)
m := args.(map[string]interface{})
targetPos := int(m["value"].(float64))
if targetPos < 0 || targetPos > 50 {
ph.Fail("Invalid throtle position.")
return nil
}
steps := 4
step := targetPos / steps
for i := 0; i < steps; i++ {
ph.Update(&Throtle{ThrotlePosition: i * step})
time.Sleep(time.Second * 5)
}
return Throtle{ThrotlePosition: targetPos}
})
//Event generator. For demo purposes event geneator generates some sample events, clients can subscribe to.
go func() {
for {
s.EmitEvent("critical-temperature-event", &CriticalEvent{EventData: "temperature -> 192°C and rasing."})
time.Sleep(time.Second * 5)
}
}()
}
func (mb *MQTT_1) setup(ctxPath string, wos *server.WotServer) {
deviceTopic := str.Concat(ctxPath, "/#")
token2 := mb.client.Subscribe(deviceTopic, 0, mb.eventHandler(ctxPath, wos))
if token2.Wait() && token2.Error() != nil {
log.Fatal(token2.Error)
os.Exit(1)
}
log.Info("MQTT_1 Backend: subscribed to device topic -> ", deviceTopic)
for _, p := range wos.GetDescription().Properties {
propPath := str.Concat(ctxPath, "/", p.Name)
wos.OnGetProperty(*p.Name, func() interface{} {
return mb.values[propPath]
})
if *p.Writable {
wos.OnUpdateProperty(*p.Name, func(payload interface{}) {
mb.publish(propPath, payload)
})
}
}
}
