Why doesn't a trigger platform for state attributes exist?

Archive Month of "What the heck?!" (2020)
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Currently there’s no direct way to trigger on a state attribute of an entity. You either have to make a template sensor that grabs the state attribute you want (or use the attributes custom integration that creates sensors based on a certain attribute in entities you define) and use it in a state trigger, or use a template trigger. Something like this would be nice:

trigger:
- platform: attribute
  entity_id: climate.thermostat
  attribute: hvac_action
  to: 'cooling'

As much as I actually enjoy templating, this would still be useful.

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I agree we should add something like this.

I think we can even combine this with the current state trigger (and condition as well)

trigger:
- platform: state
  entity_id: climate.thermostat
  attribute: hvac_action
  to: 'cooling'

Because attribute is an optional field. If it is provided, use the attribute, else the state.

That said, we should limit and convert attributes into separate sensors as much as possible.

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Or value_template to be consistent with numeric_state.

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4

To be honest, I am not sure whether this always worked, but it does now (example):

- alias: "Media player: sync KEF LS50 and TV volume"
  trigger:
    - platform: state
      entity_id: media_player.kef_ls50
    - platform: state
      entity_id: media_player.tv
  condition:
    condition: template
    value_template: >
      {{ trigger.from_state.attributes["volume_level"] != trigger.to_state.attributes["volume_level"] }}
...

I used to also go through the “template sensor of an attribute”-route, however, this seems to work now (even though I think I tried this a few months before…)

5

I’m not sure I fully agree with you here. I understand that the route for Home Assistant have been to create separate entities for all kinds of data a device would provide and we end up with so many entities.
Take power consumption as an example. I believe power consumption should always be an attribute of an entity instead of its own entity but I also understand thats up to the integration to define atm.
Battery level would be another one.

Since attributes “cant” be used at the same places as entities we need to create template entities for them.
Why not make attributes addressable everywhere like many 3rd party integrations does like climate.thermostat.attribute.battery_level or even climate.thermostat.battery_level? That way we can use it in lovelace, scripts or automations.

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6

Right, I’ve done this before too. It’s still clunky though and is triggering on every state/attribute change of those entities to check the template condition.

7

Alright first PR to implement this:

This implements the condition part, the trigger part I will do separately.

Examples:

- condition: state
  entity_id: climate.living_room_thermostat
  attribute: hvac_mode
  state: heat

- condition: numeric_state
  entity_id: climate.living_room_thermostat
  attribute: temperature
  above: 20
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8

I think it makes sense to implement this similarly to appdaemon. Make it part of the state change/conditions and only trigger on specific attributes if they are supplied. Prevents having to have a completely separate trigger type and I’ve found it quite natural to use.

[edit] looks like @Frenck beat me to it :smiley:

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3 Likes