Merge pull request #163 from ettisan/switchcmds2

Switch cmds

README.md

@@ -12,6 +12,7 @@ It offers the following functionality through built-in components:
  * Track and control [Google Chromecasts](http://www.google.com/intl/en/chrome/devices/chromecast)
  * Track running services by monitoring `ps` output
  * Track and control [Tellstick devices and sensors](http://www.telldus.se/products/tellstick)
+ * Control low-cost 433 MHz remote control wall-socket devices (https://github.com/r10r/rcswitch-pi) and other switches that can be turned on/off with shell commands
  * Turn on the lights when people get home after sun set
  * Turn on lights slowly during sun set to compensate for light loss
  * Turn off all lights and devices when everybody leaves the house

homeassistant/components/switch/command_switch.py

+# -*- coding: utf-8 -*-
+"""
+homeassistant.components.switch.command_switch
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Allows to configure custom shell commands to turn a switch on/off.
+"""
+import logging
+from homeassistant.helpers.entity import ToggleEntity
+from homeassistant.const import STATE_ON, STATE_OFF, DEVICE_DEFAULT_NAME
+import subprocess
+
+_LOGGER = logging.getLogger(__name__)
+
+
+# pylint: disable=unused-argument
+def setup_platform(hass, config, add_devices_callback, discovery_info=None):
+    """ Find and return switches controlled by shell commands. """
+
+    switches = config.get('switches', {})
+    devices = []
+
+    for dev_name, properties in switches.items():
+        devices.append(
+            CommandSwitch(
+                dev_name,
+                properties.get('oncmd', 'true'),
+                properties.get('offcmd', 'true')))
+
+    add_devices_callback(devices)
+
+
+class CommandSwitch(ToggleEntity):
+    """ Represents a switch that can be togggled using shell commands """
+    def __init__(self, name, command_on, command_off):
+        self._name = name or DEVICE_DEFAULT_NAME
+        self._state = STATE_OFF
+        self._command_on = command_on
+        self._command_off = command_off
+
+    @staticmethod
+    def _switch(command):
+        """ Execute the actual commands """
+        _LOGGER.info('Running command: %s', command)
+
+        success = (subprocess.call(command, shell=True) == 0)
+
+        if not success:
+            _LOGGER.error('Command failed: %s', command)
+
+        return success
+
+    @property
+    def should_poll(self):
+        """ No polling needed """
+        return False
+
+    @property
+    def name(self):
+        """ The name of the switch """
+        return self._name
+
+    @property
+    def state(self):
+        """ Returns the state of the switch. """
+        return self._state
+
+    @property
+    def is_on(self):
+        """ True if device is on. """
+        return self._state == STATE_ON
+
+    def turn_on(self, **kwargs):
+        """ Turn the device on. """
+        if CommandSwitch._switch(self._command_on):
+            self._state = STATE_ON
+
+    def turn_off(self, **kwargs):
+        """ Turn the device off. """
+        if CommandSwitch._switch(self._command_off):
+            self._state = STATE_OFF