Issue: Different Mqtt topic based on several sensor state

Configuration
,
1

Hi all,
I’m trying to create an automation that push an Mqtt topic based on the state of various sensors.
After several attempt, this is how my code looks right now

- service: mqtt.publish
      data_template:
        topic: >
          {%- set sensors = ["binary_sensor.soil_1", "binary_sensor.soil_2", "binary_sensor.soil_3", "binary_sensor.soil_4", "binary_sensor.soil_5"] -%}
          {%- for sensor in sensors if is_state(sensor, 'on') -%}
            {% if loop.length < 1-%}
              {% if loop.first-%}
                wemosgarden/soilsensorled/green
              {% endif %}
            {% elif loop.length >= 3-%}
              {% if loop.first-%}
                wemosgarden/soilsensorled/red
              {% endif %}
            {% else %}
              wemosgarden/soilsensorled/yellow
            {% endif %}
          {%- endfor -%}

If I try this setup in the template editor it works, and the automation load without error.
But when I trigger the automation the topic isn’t published.
What am I doing wrong?

thanks in advance for any hint

2

don’t you need a payload?

3

No I just need to publish the topic.
Then the message is read by an esp32 board to activate different GPIO output.

However I’ve tried using payload_template like this:

- service: mqtt.publish
      data_template:
        topic: wemosgarden/soilsensorled/
        payload_template: >-
          {%- set sensors = ["binary_sensor.soil_1", "binary_sensor.soil_2", "binary_sensor.soil_3", "binary_sensor.soil_4", "binary_sensor.soil_5"] -%}
          {%- for sensor in sensors if is_state(sensor, 'on') -%}
            {% if loop.length < 1-%}
              {% if loop.first-%}
                green
              {% endif %}
          .....

this way the topic is published but not the payload.
So the problem is in the template, but it give no errors and I can’t figure out what I’m doing wrong.