Repository: XKNX/xknx (python)

Issue:
Switch: add auto-off function
Sometimes it is required to s always send a "OFF" right after sending a "ON" eg. for door openers. 
I suggest to add a `reset_after` option to Switch, just like BinarySensor, to send the "OFF" telegram after a timer is finished.

Pull request:
Allow resetting switches after x seconds
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<!--
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## Description

Allows switches to be turned off after x seconds. Similar as to how binary sensors do it except that switches send the OFF telegram to the bus.

Note: Tests currently fail - not sure why..

Fixes #438 

<!--
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## Type of change

- [x] New feature (non-breaking change which adds functionality)
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] This change requires a documentation update

# Checklist:

- [x] I have performed a self-review of my own code
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my feature works


Patch:
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
index f470c332..29b7fbe0 100644
--- a/.github/pull_request_template.md
+++ b/.github/pull_request_template.md
@@ -2,33 +2,33 @@
   You are awesome! Thanks for contributing to our project!
   Please, DO NOT DELETE ANY TEXT from this template!.
 -->
-
+## Description
 <!--
 Please include a summary of the change and which issue is fixed.
 Please also include relevant motivation and context.
 List any dependencies that are required for this change.
 -->
-## Description
-
 
 
 Fixes # (issue)
 
+## Type of change
 <!--
 Please tick the applicable options.
 NOTE: Ticking multiple options most likely indicates
 that your change is to big and it is suggested to split it into several smaller PRs.
 -->
-## Type of change
 
 - [ ] Bug fix (non-breaking change which fixes an issue)
 - [ ] New feature (non-breaking change which adds functionality)
 - [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
 - [ ] This change requires a documentation update
 
-# Checklist:
+## Checklist:
 
 - [ ] I have performed a self-review of my own code
-- [ ] I have made corresponding changes to the documentation
-- [ ] My changes generate no new warnings
-- [ ] I have added tests that prove my fix is effective or that my feature works
+- [ ] The documentation has been adjusted accordingly
+- [ ] The changes generate no new warnings
+- [ ] Tests have been added that prove the fix is effective or that the feature works
+- [ ] The changes are documented in the changelog
+- [ ] The Homeassistant plugin has been adjusted in case of new config options
diff --git a/home-assistant-plugin/custom_components/xknx/const.py b/home-assistant-plugin/custom_components/xknx/const.py
index 8bb99529..b5bdd447 100644
--- a/home-assistant-plugin/custom_components/xknx/const.py
+++ b/home-assistant-plugin/custom_components/xknx/const.py
@@ -18,6 +18,7 @@ DOMAIN = "xknx"
 
 CONF_STATE_ADDRESS = "state_address"
 CONF_SYNC_STATE = "sync_state"
+CONF_RESET_AFTER = "reset_after"
 
 
 class ColorTempModes(Enum):
diff --git a/home-assistant-plugin/custom_components/xknx/factory.py b/home-assistant-plugin/custom_components/xknx/factory.py
index 157565c4..9e721817 100644
--- a/home-assistant-plugin/custom_components/xknx/factory.py
+++ b/home-assistant-plugin/custom_components/xknx/factory.py
@@ -202,6 +202,7 @@ def _create_switch(knx_module: XKNX, config: ConfigType) -> XknxSwitch:
         name=config[CONF_NAME],
         group_address=config[CONF_ADDRESS],
         group_address_state=config.get(SwitchSchema.CONF_STATE_ADDRESS),
+        reset_after=config.get(SwitchSchema.CONF_RESET_AFTER),
     )
 
 
diff --git a/home-assistant-plugin/custom_components/xknx/schema.py b/home-assistant-plugin/custom_components/xknx/schema.py
index a224d9cb..89a6fac7 100644
--- a/home-assistant-plugin/custom_components/xknx/schema.py
+++ b/home-assistant-plugin/custom_components/xknx/schema.py
@@ -15,6 +15,7 @@ from homeassistant.const import (
 import homeassistant.helpers.config_validation as cv
 
 from .const import (
+    CONF_RESET_AFTER,
     CONF_STATE_ADDRESS,
     CONF_SYNC_STATE,
     OPERATION_MODES,
@@ -86,7 +87,7 @@ class BinarySensorSchema:
     CONF_SYNC_STATE = CONF_SYNC_STATE
     CONF_IGNORE_INTERNAL_STATE = "ignore_internal_state"
     CONF_CONTEXT_TIMEOUT = "context_timeout"
-    CONF_RESET_AFTER = "reset_after"
+    CONF_RESET_AFTER = CONF_RESET_AFTER
 
     DEFAULT_NAME = "KNX Binary Sensor"
 
@@ -253,6 +254,7 @@ class SwitchSchema:
     """Voluptuous schema for KNX switches."""
 
     CONF_STATE_ADDRESS = CONF_STATE_ADDRESS
+    CONF_RESET_AFTER = CONF_RESET_AFTER
 
     DEFAULT_NAME = "KNX Switch"
     SCHEMA = vol.Schema(
@@ -260,6 +262,7 @@ class SwitchSchema:
             vol.Required(CONF_ADDRESS): cv.string,
             vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
             vol.Optional(CONF_STATE_ADDRESS): cv.string,
+            vol.Optional(CONF_RESET_AFTER): cv.positive_float,
         }
     )
 
diff --git a/xknx/devices/switch.py b/xknx/devices/switch.py
index 670eb569..0a9dab20 100644
--- a/xknx/devices/switch.py
+++ b/xknx/devices/switch.py
@@ -6,6 +6,7 @@ It provides functionality for
 * switching 'on' and 'off'.
 * reading the current state from KNX bus.
 """
+import asyncio
 import logging
 
 from xknx.remote_value import RemoteValueSwitch
@@ -22,6 +23,7 @@ class Switch(Device):
         self,
         xknx,
         name,
+        reset_after=None,
         group_address=None,
         group_address_state=None,
         device_updated_cb=None,
@@ -30,6 +32,10 @@ class Switch(Device):
         # pylint: disable=too-many-arguments
         super().__init__(xknx, name, device_updated_cb)
 
+        self.reset_after = reset_after
+        self._reset_task = None
+        self.state = False
+
         self.switch = RemoteValueSwitch(
             xknx,
             group_address,
@@ -42,6 +48,11 @@ class Switch(Device):
         """Iterate the devices RemoteValue classes."""
         yield self.switch
 
+    def __del__(self):
+        """Destructor. Cleaning up if this was not done before."""
+        if self._reset_task:
+            self._reset_task.cancel()
+
     @classmethod
     def from_config(cls, xknx, name, config):
         """Initialize object from configuration structure."""
@@ -55,12 +66,6 @@ class Switch(Device):
             group_address_state=group_address_state,
         )
 
-    @property
-    def state(self):
-        """Return the current switch state of the device."""
-        # None will return False
-        return bool(self.switch.value)
-
     async def set_on(self):
         """Switch on switch."""
         await self.switch.on()
@@ -82,7 +87,18 @@ class Switch(Device):
 
     async def process_group_write(self, telegram):
         """Process incoming and outgoing GROUP WRITE telegram."""
-        await self.switch.process(telegram)
+        if await self.switch.process(telegram):
+            self.state = self.switch.value
+            if self.reset_after is not None and self.state:
+                if self._reset_task:
+                    self._reset_task.cancel()
+                self._reset_task = asyncio.create_task(
+                    self._reset_state(self.reset_after)
+                )
+
+    async def _reset_state(self, wait_seconds: float):
+        await asyncio.sleep(wait_seconds)
+        await self.set_off()
 
     def __str__(self):
         """Return object as readable string."""


Test patch:
diff --git a/test/devices_tests/switch_test.py b/test/devices_tests/switch_test.py
index 42f651b2..a9520431 100644
--- a/test/devices_tests/switch_test.py
+++ b/test/devices_tests/switch_test.py
@@ -76,6 +76,47 @@ class TestSwitch(unittest.TestCase):
 
         self.assertEqual(switch.state, False)
 
+    def test_process_reset_after(self):
+        """Test process reset_after."""
+        xknx = XKNX()
+        reset_after_sec = 0.001
+        switch = Switch(
+            xknx, "TestInput", group_address="1/2/3", reset_after=reset_after_sec
+        )
+        telegram_on = Telegram(
+            group_address=GroupAddress("1/2/3"), payload=DPTBinary(1)
+        )
+
+        self.loop.run_until_complete(switch.process(telegram_on))
+        self.assertTrue(switch.state)
+        self.assertEqual(xknx.telegrams.qsize(), 0)
+        self.loop.run_until_complete(asyncio.sleep(reset_after_sec * 2))
+        self.assertEqual(xknx.telegrams.qsize(), 1)
+        self.loop.run_until_complete(switch.process(xknx.telegrams.get_nowait()))
+        self.assertFalse(switch.state)
+
+    def test_process_reset_after_cancel_existing(self):
+        """Test process reset_after cancels existing reset tasks."""
+        xknx = XKNX()
+        reset_after_sec = 0.01
+        switch = Switch(
+            xknx, "TestInput", group_address="1/2/3", reset_after=reset_after_sec
+        )
+        telegram_on = Telegram(
+            group_address=GroupAddress("1/2/3"), payload=DPTBinary(1)
+        )
+
+        self.loop.run_until_complete(switch.process(telegram_on))
+        self.assertTrue(switch.state)
+        self.assertEqual(xknx.telegrams.qsize(), 0)
+        self.loop.run_until_complete(asyncio.sleep(reset_after_sec / 2))
+        # half way through the reset timer
+        self.loop.run_until_complete(switch.process(telegram_on))
+        self.assertTrue(switch.state)
+
+        self.loop.run_until_complete(asyncio.sleep(reset_after_sec / 2))
+        self.assertEqual(xknx.telegrams.qsize(), 0)
+
     def test_process_callback(self):
         """Test process / reading telegrams from telegram queue. Test if callback was called."""
         # pylint: disable=no-self-use