Template not firing within "value_template"

[jpurdy647 (Joshua Purdy)]

I’m pretty new to HASSIO so I may be missing something simple but I have been confused and unable to get jinja to parse and output the value of a light entity’s brightness attribute. I am using a template to accomplish this, and per the docs I am using the state_attr function rather than polling directly from the sates object which could be uninitialized on startup.

Something I am unsure of is the difference between value and value_template. I have seen both used. I thought jinja parsed everything and replaced all portions of yaml within the special brackets? If not does it only parse within the _template fields?

Also, is there an issue with how I have formatted the yaml below to grab the brightness into a variable? (Using the variables integration through HACS)

Thank you so much for helping me understand this more fully!

show_name: true
show_icon: true
type: button
tap_action:
  action: call-service
  service: variable.update_sensor
  target:
    entity_id: sensor.var
  data:
    value_template: "{{ state_attr('light.upstairs_hallway_spot_lights', 'brightness') }}"
entity: light.living_room_entries_floodlight

[jpurdy647 (Joshua Purdy)]

Here is the result of that execution, just the string I typed unparsed:

[Didgeridrew]

YAML syntax to set timer.start duration: with an input_datetime entity?

The issue is that you are trying to use templating in the action block of a Dashboard card. Most core cards do not accept templating at all, and even custom cards that do accept templating, often do not allow it in actions. The most reliable workaround is to move your action with templated logic into a script, then have the button action call the script.

[jpurdy647 (Joshua Purdy)]

Darn.

Is there a way to reference the value of an attribute as an input for a service call in a card?

I am trying to create a button that records the current brightness of a light as a preset on a hold click, and sets the light to the brightness preset on a normal click.

I’ll use a script if needed but it seems overkill for so simple a need. Do you know why templates are unsupported in cards?

[Didgeridrew]

@jpurdy647

Do you know why templates are unsupported in cards?

I think I read an explanation once, but I don’t remember the specifics… it’s probably a combination of load order, dashboard stability, and efficiency.

@jpurdy647

I am trying to create a button that records the current brightness of a light as a preset on a hold click, and sets the light to the brightness preset on a normal click.

While it’s not exactly the same, you may be able to get what you want by using the scene.create service to create a scene on the fly for your light then scene.turn_on to recall the state.

show_name: true
show_icon: true
type: button
hold_action:
  action: call-service  
  service: scene.create
  data:
    scene_id: temp_hallway_spot_lights
    snapshot_entities:
      - light.upstairs_hallway_spot_lights
tap_action:
  action: call-service
  service: scene.turn_on
  target:
    entity_id: scene.temp_hallway_spot_lights

[jpurdy647 (Joshua Purdy)]

That works perfect! The only functionality that I can’t replicate is I was hoping to display the preset target brightness on the button as well, but that would require a template in the name field or a script to retroactively update the button name with the target percent. I might do it with a script later, unless you know a simpler way for that too!