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Documentation

Index

• type MqttConnection
  • func NewMqttConnection(topicRoot string, qualityOfService int, options *mqtt.ClientOptions) (c MqttConnection)
  • func (c MqttConnection) Disconnect(quiesce uint)
  • func (c MqttConnection) Publish(obis, value, unit string, retained, updateOnlyIfChanged bool) (updated bool)
  • func (c MqttConnection) Reconnect()
  • func (c MqttConnection) Subscribe(obis string, callback mqtt.MessageHandler) (success bool)
• type Settings

Types

type MqttConnection

type MqttConnection struct {
	// contains filtered or unexported fields
}

Struct holding the MQTT client and user settings

func NewMqttConnection

func NewMqttConnection(topicRoot string, qualityOfService int, options *mqtt.ClientOptions) (c MqttConnection)

Creating a new MQTT connection Parameter: * topicRoot: common prefix of a MQTT topic for this connection * qualityOfService: the MQTT quality of service for all operations * options: Return: * c: MqttConnection struct, containing a connected MQTT client and the specified parameters

func (MqttConnection) Disconnect

func (c MqttConnection) Disconnect(quiesce uint)

Disconnect from MQTT broker The does not invalidate the connection struct, Reconnect re-enables all functionality Parameter: * quiesce: amount of milliseconds to wait before closing

func (MqttConnection) Publish

func (c MqttConnection) Publish(obis, value, unit string, retained, updateOnlyIfChanged bool) (updated bool)

Publishes a message to the MQTT broker Parameter:

• obis: the obis code, which will be used as topic suffix
• value: the MQTT message containing the value
• unit: if a unit is specified it will be appended to the MQTT message. To drop the unit use an empty string ""
• retained: set to true if the message should be retained by the MQTT server
• updateOnlyIfChanged: set to true to publish the message only if the value differs from the previous This avoids short interval subscriber updates without any value change

Return: * updated: true if a message was published (depending on updateOnlyIfChanged!)

func (MqttConnection) Reconnect

func (c MqttConnection) Reconnect()

(Re)Connects the MQTT client

func (MqttConnection) Subscribe

func (c MqttConnection) Subscribe(obis string, callback mqtt.MessageHandler) (success bool)

Registers as subscriber to the specified topic Parameter: * obis: the topic extension to subscribe (topicRoot + extension) * callback: the callback function to call once a new message arrives (specify your own) Return: success: true is subscribing the topic was successful

type Settings

type Settings struct {
	// contains filtered or unexported fields
}

Struct holding user settings for the connection