Using variables to form an entity name inside a template

Configuration
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1

Hi, I have been looking here, on the docs, on jinja docs, debugging on the developers tools and on the log but cannot get it right…

I am trying to create a generic script to test and act on a number of switches so I need to test it against a template condition on a choose statement and then use it on a formula for a variable to another script. But I cannot evaluate the expressions:

value_template: "{{ ( position | int ) > (states('sensor.{{ shade }}')|int + 9)|int}}"

and

                variables:
                  deltaporcento: "{{ (position | int) - (states('sensor.{{ shade }}') | int ) | int }}"

Is there a way I can do it? I assumed so as I can use the entity formed for other tests…
Can someone please please help me as this string/code mix is making me crazy?

I can also publish the complete script section if there should be another way to accomplish that…

2

in order to use blanket variable names like ‘position’, or ‘shade’, you need to declare them ahead of time unless the docs say they are ‘in the environment’ already.

{% set shade = 'my_shade' %}
{% set postion = 4 %}

Then after you can perform tests in the template editor, however your tests are incorrect. When accessing variables, you don’t need extra {{ }} or {% %}. {{ }} returns a whole line of code as a string. {% %} executes a line of code without returning anything.

Also, when you’re trying to combine values, you need to combine them properly. Combining strings can be done using + or ~. Typically ~ is the safest bet.

Lastly, you only need to convert strings to other types. Using |int will convert whatever you’re using to an integer. Typically predefined variables in templates are already declared as a specific type, so you don’t need to convert it. Using states(), you do because it will always return a string.

{{ position - states('sensor.' ~ shade) | int }}

I believe your biggest hindrance right now is understanding types in code. I recommend doing a short interactive online python tutorial. That should familiarize yourself with typing. Then use the jinja documents once you understand that. If you can find a jinja tutorial, great, do that. But those are harder to find.

10 Likes
3

Thank you very much for your response!

30+ years ago I did some programming and I did it on strongly typed languages. What I am very new to are undeclared variables and objects. I will try to find a tutorial for python types handling, thanks.
I know I am “filtering” too much to int, but that is exactly because I dont know what type they are and I am afraid! Position, which seems to be a pre-defined value for the cover entity, is float, but I could not find this info anywhere…

Anyway, your example saved my day! Pointed me the boundaries!

The ~ did the trick there and everything is working now.

I will leave my code beneath as this explanation might help someone as others have helped me.

Thank you again and I too owe you one!

cover:
  - platform: template
    covers:
      suite_shades:
        device_class: shade
        friendly_name: "Suite Shades"
        position_template: "{{ states('sensor.shades') }}"
        open_cover:
          service: script.open_shades
          data:
            shade: Shades
        close_cover:
          service: script.close_shades
          data:
            shade: Shades
        stop_cover:
          service: script.stop_shades
          data:
            shade: Shades
        set_cover_position:
          service: script.posiciona_shades
          data_template:
            position: "{{ position }}"
            shade: shades

And scripts.yaml:

  close_shades:
    mode: single
    sequence:
      - service: script.turn_on
        data:
          entity_id:
            - script.lower_shades
        data_template:
          variables:
            deltaporcento: 100
            shade: "{{ shade }}"
      - service: mqtt.publish
        data:
          topic: "void/Shades/Position"
          payload: 0

  open_shades:
    mode: single
    sequence:
      - service: script.turn_on
        data:
          entity_id:
            - script.rise_shades
        data_template:
          variables:
            deltaporcento: 100
            shade: "{{ shade }}"
      - service: mqtt.publish
        data:
          topic: "void/Shades/Position"
          payload: 100

  posiciona_shades:
    mode: single
    sequence:
#      - service: system_log.write
#        data_template:
#          message: "{{ ( position | int ) - ( states('sensor.'~shade) | int ) }}"
      - choose:
        # IF must open_shades
        - conditions:
            - condition: template
              value_template: "{{ ( position | int ) > (states('sensor.'~shade)|int + 9) }}" #min 10% change
          sequence:
            - service: script.turn_on
              entity_id:
                - script.rise_shades 
              data_template:
                variables:
                  deltaporcento: "{{ ( position | int ) - ( states('sensor.'~shade) ) | int }}"
                  shade: "{{ shade }}"
            - service: mqtt.publish
              data:
                topic: "void/Shades/Position"
              data_template:
                payload: "{{ position }}"
      # ELSEIF must close_shades
        - conditions:
            - condition: template
              value_template: "{{ ( position | int ) < ( states('sensor.'~shade) ) | int - 9 }}" #min 10% change
          sequence:
#            - service: script.lower_shades
            - service: script.turn_on
              entity_id:
                - script.lower_shades
              data_template:
                variables:
                  deltaporcento: "{{ ( ( states('sensor.'~shade) ) | int ) - ( position | int ) }}"
                  shade: "{{ shade }}"
            - service: mqtt.publish
              data:
                topic: "void/Shades/Position"
              data_template:
                payload: "{{ position }}"

  lower_shades:
    mode: single
    sequence:
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}"
      - delay:
          milliseconds: 1000
      - service: switch.turn_on
        data_template:
          entity_id: "switch.{{ shade }}_up"
      - delay:
          milliseconds: 1000
      - service: switch.turn_on
        data_template:
          entity_id: "switch.{{ shade }}"
      - delay: 
          milliseconds: "{{ deltaporcento|int * 140 }}" # Takes 14s to close
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}"

  rise_shades:
    mode: single
    sequence:
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}"
      - delay:
          milliseconds: 1000
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}_up"
      - delay:
          milliseconds: 1000
      - service: switch.turn_on
        data_template:
          entity_id: "switch.{{ shade }}"
      - delay: 
          milliseconds: "{{ deltaporcento|int * 150 }}" # Takes 15s to open
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}"
  stop_shades:
  # TODO: treat position on stop_shades
    sequence:
      - service: switch.turn_off
        data_template:
          entity_id: "switch.{{ shade }}"
4 Likes
4

Hi @petro!
I was trying something similar, but couldn’t figure it out. I wanted to go from this
{% set lc = as_timestamp('states.sensor.xy_linkquality.last_changed') | int %}
to this:

{% set entity = 'xy_linkquality' %}
{% set lc = as_timestamp(states.sensor. ~ entity.last_changed) | int %}

but unfortunately a string doesn’t work in this case with the state object. Is there a way to integrate the variable?

1 Like
5

you don’t need to cast the int and you just need to access the state object properly

{% set entity = 'xy_linkquality' %}
{% set lc = as_timestamp(states.sensor[entity].last_changed) %}
1 Like
6

Thank you very much!
May I ask, where is something like using these brackets "[ ]"for variables documented? Couldn’t find anything.
P.S.: the int was useful for my code :slight_smile:

7

It’s not documented anywhere in HA, it’s documented in Jinja’s docs as this is basic jinja functionality.

https://jinja.palletsprojects.com/en/3.0.x/templates/#variables

1 Like