Added Adafruit IO backend

platypush/backend/adafruit/io.py

@@ -0,0 +1,81 @@
+from platypush.backend import Backend
+from platypush.context import get_plugin
+from platypush.message.event.adafruit import ConnectedEvent, DisconnectedEvent, \
+    FeedUpdateEvent
+
+
+class AdafruitIoBackend(Backend):
+    """
+    Backend that listens to messages received over the Adafruit IO message queue
+
+    Triggers:
+
+        * :class:`platypush.message.event.adafruit.ConnectedEvent` when the
+            backend connects to the Adafruit queue
+        * :class:`platypush.message.event.adafruit.DisconnectedEvent` when the
+            backend disconnects from the Adafruit queue
+        * :class:`platypush.message.event.adafruit.FeedUpdateEvent` when an
+            update event is received on a monitored feed
+
+    Requires:
+
+        * The :class:`platypush.plugins.adafruit.io.AdafruitIoPlugin` plugin to
+            be active and configured.
+    """
+
+    def __init__(self, feeds, *args, **kwargs):
+        """
+        :param feeds: List of feed IDs to monitor
+        :type feeds: list[str]
+        """
+
+        super().__init__(*args, **kwargs)
+        self.feeds = feeds
+        self._client = None
+
+    def _init_client(self):
+        if self._client:
+            return
+
+        from Adafruit_IO import MQTTClient
+        plugin = get_plugin('adafruit.io')
+        if not plugin:
+            raise RuntimeError('Adafruit IO plugin not configured')
+
+        self._client = MQTTClient(plugin._username, plugin._key)
+        self._client.on_connect = self.on_connect()
+        self._client.on_disconnect = self.on_disconnect()
+        self._client.on_message = self.on_message()
+
+    def on_connect(self):
+        def _handler(client):
+            self.bus.post(ConnectedEvent())
+        return _handler
+
+    def on_disconnect(self):
+        def _handler(client):
+            self.bus.post(DisconnectedEvent())
+        return _handler
+
+    def on_message(self):
+        def _handler(client, feed, data):
+            self.bus.post(FeedUpdateEvent(feed=feed, data=data))
+        return _handler
+
+    def run(self):
+        super().run()
+
+        self.logger.info(('Initialized Adafruit IO backend, listening on ' +
+                          'feeds {}').format(self.feeds))
+
+        while not self.should_stop():
+            try:
+                self._init_client()
+                self._client.connect()
+                self._client.loop_blocking()
+            except Exception as e:
+                self.logger.exception(e)
+                self._client = None
+
+
+# vim:sw=4:ts=4:et:

platypush/message/event/adafruit.py

@@ -0,0 +1,31 @@
+from platypush.message.event import Event
+
+
+class ConnectedEvent(Event):
+    """
+    Event triggered when the backend connects to the Adafruit message queue
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, feed=feed, data=data, **kwargs)
+
+
+class DisconnectedEvent(Event):
+    """
+    Event triggered when the backend disconnects from the Adafruit message queue
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, feed=feed, data=data, **kwargs)
+
+
+class FeedUpdateEvent(Event):
+    """
+    Event triggered upon Adafruit IO feed update
+    """
+
+    def __init__(self, feed, data, *args, **kwargs):
+        super().__init__(*args, feed=feed, data=data, **kwargs)
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/adafruit/io.py

@@ -62,6 +62,9 @@ class AdafruitIoPlugin(Plugin):
         """
 
         super().__init__(*args, **kwargs)
+
+        self._username = username
+        self._key = key
         self.aio = Client(username=username, key=key)
         self.throttle_seconds = throttle_seconds
 
@@ -169,24 +172,43 @@ class AdafruitIoPlugin(Plugin):
         self.aio.send_location_data(feed=feed, value=value, lat=lat, lon=lon, ele=ele)
 
     @action
-    def receive(self, feed):
+    def receive(self, feed, limit=1):
         """
-        Receive the most recent value from an Adafruit IO feed and returns it
-        as a scalar (string or number)
+        Receive data from the specified Adafruit IO feed
 
         :param feed: Feed name
         :type feed: str
+
+        :param limit: Maximum number of data points to be returned. If None,
+            all the values in the feed will be returned. Default: 1 (return most
+            recent value)
         """
 
-        value = self.aio.receive(feed).value
+        if limit == 1:
+            value = self.aio.receive(feed).value
 
-        try:
-            value = float(value)
-        except ValueError:
-            pass
+            try: value = float(value)
+            except ValueError: pass
+            return value
 
-        return value
+        values = [i.value for i in self.aio.data(feed)]
+        if limit:
+            return values[-limit:]
+        return values
+
+    @action
+    def delete(self, feed, data_id):
+        """
+        Delete a data point from a feed
+
+        :param feed: Feed name
+        :type feed: str
+
+        :param data_id: Data point ID to remove
+        :type data_id: int
+        """
+
+        self.aio.delete(feed, data_id)
 
 
 # vim:sw=4:ts=4:et:
-