Trigger based templates: when do variables resolve?

Configuration
1

I’m using some trigger based templates that get REST data and process it into multiple attributes. Several use the same code blocks so I create variables to pre-process some of the REST output to reuse in different attributes. I thought all was well until I read this in the documentation

 variables map (Optional)

Key-value pairs of variable definitions which can be referenced and used in the templates below (for trigger-based entities only).  Trigger based template entities resolve variables between triggers and actions.

(I’ve extracted the key sentence).
My question is: if the data used by the variable comes from the REST action and it is resolved BEFORE the action, where is it getting its data from?
A short extract of my template:

  - trigger:
      - platform: state
        entity_id: input_button.tideq
    action:
      - service: rest_command.tide_heights_q
        response_variable: heightsq
      - service: [there are several more]
      - variables:
          gradient: >
            {%- if heightsq.status != 200 %} {#- start by getting the query height again, plus 10 mins later #} 
              {%- from 'tide_macros.jinja' import harmonic_height %}
              {%- set height = harmonic_height(when,ts,hs)|float(0) if when<=ts|max and when>=ts|min else 'n/a' %}
              {%- set height10 = harmonic_height(when+600,ts,hs)|float(0) if when<=ts|max and when>=ts|min else 'n/a' %}
              {%- set gradient = ((height10-height)*6) %}
            {%- else %}
              {% set gradient = (30*(heightsq.content | selectattr('DateTime', 'ge', (as_datetime(state_attr('sensor.tidequerytiming','query'))+timedelta(minutes=2)).strftime('%Y-%m-%dT%H:%M:00Z')) | map(attribute='Height') | first | float(0) - heightsq.content | selectattr('DateTime', 'ge', as_datetime(state_attr('sensor.tidequerytiming','query')).strftime('%Y-%m-%dT%H:%M:00Z')) | map(attribute='Height') | first | float(0))) %}
            {%- endif %}
            {{ gradient }}
    sensor:
      - unique_id: tideq
        name: tideq
        state: "{{states('input_datetime.tidequery')}}"
        attributes:
          rate: >
            {{ gradient|round(1) }}
          flow: >
            {%- set itis = iif(gradient < 0, "ebb", "flood") %}
            {%- if gradient|abs < 0.2 %}
              Slack
            {%- elif gradient|abs > 2.0 %}
              {{"V fast "+itis }}
            {%- elif gradient|abs > 1.5 %}
              {{"Fast "+itis }}
            {%- elif gradient|abs < 0.5 %}
              {{"Slow "+itis }}
            {%- else %}
              {{ (itis+"ing")|capitalize }}
            {%- endif %}

It seems to be working, or at least it is returning credible results.

2

You are confusing two different variables.

The variables in the documentation extract you provided is at the same level as action, not a “child” of action. Since you have set up your variables at the end of an action sequence they will be resolved after the other actions in the sequence.

Where can I put variables?

1 Like
3

Thank you. I hadn’t realised there were options re where to define variables.

4

That’s what the documentation is pointing out, the option to define variables at the root level.