Type confusion (number vs string) when passing script field parameters from automation

Configuration
,
1

I am very confused how to control the type of a field parameter that I want to pass from an automation to a script.

I have an input_select with two numeric value options that I defined as strings:

  evcc_wallbox_phases_status:
    name: evcc Wallbox Phasenumschaltung
    icon: mdi:ev-station
    options:
      - "1"
      - "3"

I have an automation to fire a script when the input_select is changed:

  - id: evcc_wallbox_phases_status_changed
    alias: evcc Wallbox Phasenumschaltung ausgelöst
    trigger:
      - platform: state
        entity_id: input_select.evcc_wallbox_phases_status
    action:
      - service: script.evcc_wallbox_phase_switch_changed
        data:
          phases_selected: "{{ trigger.to_state.state }}"

In this case the field parameter will be passed to the script as a number:

From the script trace:

phases_selected: 1

If I pass the field parameter directly, it will be transferred as a string:

  - id: evcc_wallbox_phases_status_changed
    alias: evcc Wallbox Phasenumschaltung ausgelöst
    trigger:
      - platform: state
        entity_id: input_select.evcc_wallbox_phases_status
    action:
      - if:
          - condition: template
            value_template: "{{ trigger.to_state.state == '3' }}"
        then:
          - service: script.evcc_wallbox_phase_switch_changed
            data:
              phases_selected: "3"
        else:
          - service: script.evcc_wallbox_phase_switch_changed
            data:
              phases_selected: "1"

From the script trace:

phases_selected: '3'

Why is this inconsistent, it is very confusing. I tried to use filters |string but without effect.

Any ideas?

2

It’s not inconsistent.

This passes the value via a template and is therefore subjected to Home Assistant’s native typing.

phases_selected: "{{ trigger.to_state.state }}"

In other words, the template’s result is automatically assigned a type; the result appears to be numeric so its type is automatically assigned to be a number.

In contrast, this passes the value as a literal string.

phases_selected: "3"
3

Thanks, that is what I felt. Not sure whether I can agree though that it is consistent …

If I do an explicit string conversion

phases_selected: "{{ trigger.to_state.state | string }}"

the result will still be passed on to the script as number.

I tried putting additional single quotes around:

phases_selected: '"{{ trigger.to_state.state }}"'

This will be passed as string with additional quotes, which is actually correct in a sense, but again not what I am trying to achieve.

phases_selected: '"3"'

Can I somehow enforce that a string which is containing a numeric value is passed from the template as a string to the script? Or do I need to handle the conversion within the script?

4

Because native typing evaluates the template’s result and, based on the result’s appearance, sets its type. Therefore it doesn’t matter if you add a string filter; if the final result’s appearance is numeric then its type will be a number (int or float).

That would be the simplest way.

Also, why do you need to handle a numeric value as a string?

EDIT

You can also try to pass the service call’s data in JSON format.

    action:
      - service: script.evcc_wallbox_phase_switch_changed
        data: "{{ {"phases_selected": trigger.to_state.state} }}"

EDIT

Removed redundant string filter.

5

No need for the string filter there, the state will already be a string

1 Like
6

Thanks! I copy-pasted OP’s template and overlooked to remove the redundant string filter.

7

Thanks. Passing the json looks good to me. I still don’t think though that HA should do it’s own type evaluation of templates. If I say it’s a string, it’s because I want it to be :wink:

I had been using the same script with different inputs. Initially I used a switch that directly sent “1” and “3” as parameters, then I changed to an input_select and went for the template.

I am using HA for a couple of months now, my background is mostly C#. I still struggle with the way HA treats string, int and boolean types. Sometimes a number is a number, sometimes it’s a string. Sometimes off is the same as “off”, sometimes it’s not.

8

In previous versions (long ago) it didn’t. The result of every template was a string and only a string. That was far more limiting than the way it works now.

I can understand why someone would feel that way if they don’t understand how Home Assistant’s native typing works.

It works according to the simple rule: “If it looks like a duck, it’s a duck.” :slightly_smiling_face:

In your example, the template’s result looks like a number, so it’s a number.

1 Like
9

Yeah, maybe it’s just me coming from a strongly typed programming language … the whole yaml / jinja thing still makes my skin crawl :crazy_face: