Add simple REST switch

The switch can get the state via GET and set the state via POST
on a given REST resource.
It is not able to control arbitrary urls but it allows controlling
switches exposed via "real" REST.

homeassistant/components/switch/rest.py

+# -*- coding: utf-8 -*-
+"""
+homeassistant.components.switch.rest
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Allows to configure a REST switch.
+
+Configuration:
+
+switch:
+  platform: rest
+  name: "Bedroom Switch"
+  resource: "http://IP_ADDRESS/ENDPOINT"
+  body_on: "ON"
+  body_off: "OFF"
+
+Variables:
+
+resource
+*Required*
+
+name
+*Optional
+The name of the switch. Default is 'REST Switch'.
+
+body_on
+*Optional
+The body that represents enabled state. Default is "ON".
+
+body_off
+*Optional
+The body that represents disabled state. Default is "OFF".
+
+"""
+
+import logging
+import requests
+
+from homeassistant.components.switch import SwitchDevice
+
+_LOGGER = logging.getLogger(__name__)
+
+DEFAULT_NAME = "REST Switch"
+DEFAULT_BODY_ON = "ON"
+DEFAULT_BODY_OFF = "OFF"
+
+
+# pylint: disable=unused-argument
+def setup_platform(hass, config, add_devices_callback, discovery_info=None):
+    """ Add REST Switch """
+
+    resource = config.get('resource')
+
+    if resource is None:
+        _LOGGER.error("Missing required variable: resource")
+        return False
+
+    try:
+        requests.get(resource, timeout=10)
+    except requests.exceptions.MissingSchema:
+        _LOGGER.error("Missing resource or schema in configuration. "
+                      "Add http:// to your URL.")
+        return False
+    except requests.exceptions.ConnectionError:
+        _LOGGER.error("No route to device. "
+                      "Please check the IP address in the configuration file.")
+        return False
+
+    add_devices_callback([RestSwitch(
+        hass,
+        config.get('name', DEFAULT_NAME),
+        config.get('resource'),
+        config.get('body_on', DEFAULT_BODY_ON),
+        config.get('body_off', DEFAULT_BODY_OFF))])
+
+
+# pylint: disable=too-many-arguments
+class RestSwitch(SwitchDevice):
+    """ Represents a switch that can be togggled using REST """
+    def __init__(self, hass, name, resource, body_on, body_off):
+        self._state = None
+        self._hass = hass
+        self._name = name
+        self._resource = resource
+        self._body_on = body_on
+        self._body_off = body_off
+
+    @property
+    def name(self):
+        """ The name of the switch. """
+        return self._name
+
+    @property
+    def is_on(self):
+        """ True if device is on. """
+        return self._state
+
+    def turn_on(self, **kwargs):
+        """ Turn the device on. """
+        request = requests.post(self._resource,
+                                data=self._body_on,
+                                timeout=10)
+        if request.status_code == 200:
+            self._state = True
+        else:
+            _LOGGER.error("Can't turn on %s. Is device offline?",
+                          self._resource)
+
+    def turn_off(self, **kwargs):
+        """ Turn the device off. """
+        request = requests.post(self._resource,
+                                data=self._body_off,
+                                timeout=10)
+        if request.status_code == 200:
+            self._state = False
+        else:
+            _LOGGER.error("Can't turn off %s. Is device offline?",
+                          self._resource)
+
+    def update(self):
+        """ Gets the latest data from REST API and updates the state. """
+        request = requests.get(self._resource, timeout=10)
+        if request.text == self._body_on:
+            self._state = True
+        elif request.text == self._body_off:
+            self._state = False
+        else:
+            self._state = None