fixed bug 863, support sets the MQTT client extended options, usage: …

…mqttAdaptor := mqtt.NewAdaptorWithAuth(...); mqttAdaptor.SetOptionsFn(func(opts *paho.ClientOptions) {opts.WillPayload = []byte("goodbye")

platforms/mqtt/mqtt_adaptor.go

@@ -32,6 +32,7 @@ type Adaptor struct {
  cleanSession bool
  client paho.Client
  qos int
+ optionsFn func(*paho.ClientOptions)
 }
 
 // NewAdaptor creates a new mqtt adaptor with specified host and client id
@@ -109,9 +110,16 @@ func (a *Adaptor) ClientKey() string { return a.clientKey }
 // SetClientKey sets the MQTT client SSL key file
 func (a *Adaptor) SetClientKey(val string) { a.clientKey = val }
 
+// SetOptionsFn sets the MQTT client extended options
+func (a *Adaptor) SetOptionsFn(fn func(*paho.ClientOptions)) { a.optionsFn = fn }
+
 // Connect returns true if connection to mqtt is established
 func (a *Adaptor) Connect() error {
- a.client = paho.NewClient(a.createClientOptions())
+ opts := a.createClientOptions()
+ if a.optionsFn != nil {
+ a.optionsFn(opts)
+ }
+ a.client = paho.NewClient(opts)
  if token := a.client.Connect(); token.Wait() && token.Error() != nil {
  return token.Error()
  }