Class: Adafruit::IO::MQTT

Inherits:
Object
  • Object
show all
Defined in:
lib/adafruit/io/mqtt.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(username, key, opts = {}) ⇒ MQTT

Returns a new instance of MQTT.



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# File 'lib/adafruit/io/mqtt.rb', line 40

def initialize(username, key, opts={})
  @options = {
    uri: 'io.adafruit.com',
    protocol: 'mqtts',
    port: 8883,
    username: username,
    key: key
  }.merge(opts)

  @connect_uri = "%{protocol}://%{username}:%{key}@%{uri}" % @options

  connect
end

Instance Attribute Details

#client ⇒ Object (readonly)

provide access to the raw MQTT library client



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# File 'lib/adafruit/io/mqtt.rb', line 38

def client
  @client
end

Instance Method Details

#connect ⇒ Object 



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# File 'lib/adafruit/io/mqtt.rb', line 54

def connect
  if @client.nil? || !@client.connected?
    @client = ::MQTT::Client.connect @connect_uri, @options[:port], ack_timeout: 10
  end
end

#disconnect ⇒ Object 



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# File 'lib/adafruit/io/mqtt.rb', line 60

def disconnect
  if @client && @client.connected?
    @client.disconnect
  end
end

#get(&block) ⇒ Object

Retrieve the last value received from the MQTT connection for any subscribed feeds or groups. This is a blocking method, which means it won’t return until a message is retrieved.

Returns [topic, message] or yields it into the given block.

With no block:

mqtt_client.subscribe('feed-key')
loop do
  topic, message = mqtt_client.get
  # do something
end

With a block:

mqtt_client.subscribe('feed-key')
mqtt_client.get do |topic, message|
  # do something
end



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# File 'lib/adafruit/io/mqtt.rb', line 153

def get(&block)
  @client.get(&block)
end

#publish(key, value, location = {}) ⇒ Object

Publish value to feed with given key



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# File 'lib/adafruit/io/mqtt.rb', line 67

def publish(key, value, location={})
  raise 'client is not connected' unless @client.connected?

  topic = key_to_feed_topic(key)
  location = indifferent_keys(location)
  payload = payload_from_value_with_location(value, location)

  @client.publish(topic, payload)
end

#publish_group(key, values, location = {}) ⇒ Object

Publish to multiple feeds within a group.

  • ‘key` is a group key

  • ‘values` is a hash where keys are feed keys and values are the published value.

  • ‘location` is the optional { :lat, :lon, :ele } hash specifying the location data for this publish event.



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# File 'lib/adafruit/io/mqtt.rb', line 85

def publish_group(key, values, location={})
  raise 'client is not connected' unless @client.connected?
  raise 'values must be a hash' unless values.is_a?(Hash)

  topic = key_to_group_topic(key, false)
  location = indifferent_keys(location)
  payload = payload_from_values_with_location(values, location)

  @client.publish(topic, payload)
end

#subscribe(key, options = {}) ⇒ Object

Subscribe to the feed with the given key. Use .get to retrieve messages from subscribed feeds.

Include the { last_value: true } option if you’d like the feed to receive the last value immediately. (like MQTT retain)



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# File 'lib/adafruit/io/mqtt.rb', line 101

def subscribe(key, options={})
  raise 'client is not connected' unless @client.connected?

  topic = key_to_feed_topic(key)
  @client.subscribe(topic)

  if options[:last_value]
    @client.publish(topic + '/get', '')
  end
end

#subscribe_group(key) ⇒ Object

Subscribe to a group with the given key.

NOTE: Unlike feed subscriptions, group subscriptions return a JSON representation of the group record with a ‘feeds’ property containing a JSON object whose keys are feed keys and whose values are the last value received for that feed.



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# File 'lib/adafruit/io/mqtt.rb', line 125

def subscribe_group(key)
  raise 'client is not connected' unless @client.connected?

  topic = key_to_group_topic(key)
  @client.subscribe(topic)
end

#unsubscribe(key) ⇒ Object 



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# File 'lib/adafruit/io/mqtt.rb', line 112

def unsubscribe(key)
  raise 'client is not connected' unless @client.connected?

  topic = key_to_feed_topic(key)
  @client.unsubscribe(topic)
end