template lights turn_on missing `brightness` parameter

[AntanasGa]

The problem

in documentation: https://www.home-assistant.io/integrations/light.template/#turn_on it is noted May receive variables brightness and/or transition. with that information i was attempting to implement an integration, but received:

Error rendering data template: UndefinedError: 'brightness' is undefined

I'm expecting it to have the brightness value as int | None because turning the light on does restore its brightness

What version of Home Assistant Core has the issue?

core-2023.10.3

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

No response

Link to integration documentation on our website

No response

Diagnostics information

No response

Example YAML snippet

- platform: template
  lights:
    l_light_1:
      unique_id: restll1
      friendly_name: "Lounge light 1"
      turn_on:
        service: rest_command.set_dimmer_level
        data:
          brightness: "{{ (brightness | int(1)) * 256}}"
          id: 17
      turn_off:
        service: rest_command.set_dimmer_level
        data:
          brightness: 0
          id: 17
      set_level:
        service: rest_command.set_dimmer_level
        data:
          brightness: "{{ brightness * 256 }}" # accepts u16 value
          id: 17

Anything in the logs that might be useful for us?

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py", line 226, in handle_call_service
    await hass.services.async_call(
  File "/usr/src/homeassistant/homeassistant/core.py", line 2012, in async_call
    response_data = await coro
                    ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2049, in _execute_service
    return await target(service_call)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 235, in handle_service
    return await service.entity_service_call(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 876, in entity_service_call
    response_data = await _handle_entity_call(
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 948, in _handle_entity_call
    result = await task
             ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/light/__init__.py", line 580, in async_handle_light_on_service
    await light.async_turn_on(**filter_turn_on_params(light, params))
  File "/usr/src/homeassistant/homeassistant/components/template/light.py", line 421, in async_turn_on
    await self.async_run_script(
  File "/usr/src/homeassistant/homeassistant/components/template/template_entity.py", line 554, in async_run_script
    await script.async_run(
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 1578, in async_run
    return await asyncio.shield(run.async_run())
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 420, in async_run
    await self._async_step(log_exceptions=False)
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 470, in _async_step
    self._handle_exception(
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 493, in _handle_exception
    raise exception
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 468, in _async_step
    await getattr(self, handler)()
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 675, in _async_call_service_step
    params = service.async_prepare_call_from_config(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 366, in async_prepare_call_from_config
    raise HomeAssistantError(f"Error rendering data template: {ex}") from ex
homeassistant.exceptions.HomeAssistantError: Error rendering data template: UndefinedError: 'brightness' is undefined

Additional information

No response

[home-assistant[bot]]

Hey there @phracturedblue, @tetienne, @home-assistant/core, mind taking a look at this issue as it has been labeled with an integration (template) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of template can trigger bot actions by commenting:

• @home-assistant close Closes the issue.
• @home-assistant rename Awesome new title Renames the issue.
• @home-assistant reopen Reopen the issue.
• @home-assistant unassign template Removes the current integration label and assignees on the issue, add the integration domain after the command.

_{^{(message by CodeOwnersMention)}}

---

template documentation template source _{^{(message by IssueLinks)}}

[jpbede]

The brightness is only passed to the turn_on action of the template if the light.turn_on service is called with brightness.

[AntanasGa]

that is correct, but it shouldn't break the template if it doesn't have the brightness value

[issue-triage-workflows[bot]]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates. Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍 This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.

[AntanasGa]

issue persists on Core 2024.1.6

[Ubicumque]

Can confirm. Frustrating to use set_temperature with brightness. Either you ignore the brightness value or break the template if you don't call the service with both values defined. Lights works either way, template should behave equal.

[issue-triage-workflows[bot]]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates. Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍 This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.