hybridgroup.gobot/platforms/mqtt/mqtt_adaptor.go

94 lines
2.2 KiB
Go

package mqtt
import (
paho "github.com/eclipse/paho.mqtt.golang"
multierror "github.com/hashicorp/go-multierror"
)
type Adaptor struct {
name string
Host string
clientID string
username string
password string
client paho.Client
}
// NewAdaptor creates a new mqtt adaptor with specified host and client id
func NewAdaptor(host string, clientID string) *Adaptor {
return &Adaptor{
name: "MQTT",
Host: host,
clientID: clientID,
}
}
func NewAdaptorWithAuth(host, clientID, username, password string) *Adaptor {
return &Adaptor{
name: "MQTT",
Host: host,
clientID: clientID,
username: username,
password: password,
}
}
func (a *Adaptor) Name() string { return a.name }
func (a *Adaptor) SetName(n string) { a.name = n }
// Connect returns true if connection to mqtt is established
func (a *Adaptor) Connect() (err error) {
a.client = paho.NewClient(createClientOptions(a.clientID, a.Host, a.username, a.password))
if token := a.client.Connect(); token.Wait() && token.Error() != nil {
err = multierror.Append(err, token.Error())
}
return
}
// Disconnect returns true if connection to mqtt is closed
func (a *Adaptor) Disconnect() (err error) {
if a.client != nil {
a.client.Disconnect(500)
}
return
}
// Finalize returns true if connection to mqtt is finalized successfully
func (a *Adaptor) Finalize() (err error) {
a.Disconnect()
return
}
// Publish a message under a specific topic
func (a *Adaptor) Publish(topic string, message []byte) bool {
if a.client == nil {
return false
}
a.client.Publish(topic, 0, false, message)
return true
}
// Subscribe to a topic, and then call the message handler function when data is received
func (a *Adaptor) On(event string, f func(s []byte)) bool {
if a.client == nil {
return false
}
a.client.Subscribe(event, 0, func(client paho.Client, msg paho.Message) {
f(msg.Payload())
})
return true
}
func createClientOptions(clientId, raw, username, password string) *paho.ClientOptions {
opts := paho.NewClientOptions()
opts.AddBroker(raw)
opts.SetClientID(clientId)
if username != "" && password != "" {
opts.SetPassword(password)
opts.SetUsername(username)
}
opts.AutoReconnect = false
return opts
}