Template extension to parse ISO8601 duration

[eifinger]

I want to move my existing Alexa skill Alexa tell Home Assistant to turn off kitchen in 10 minutes from an Appdaemon backend to Homeassistant intent_script. The only thing missing is a way to convert the duration which is being parsed and provided as a slot value in the ISO8601 duration form of PT10M to something usable in scripts.

A possible solution could be to implement a new template parse_duration (or a better name) using https://github.com/gweis/isodate/ so that I can create the following script:

intent_script:
  TurnOffInXIntent:  # Intent type
    speech:
      text: Okay
    action:
      - delay: {{ parse_duration(duration_slot) }}
      - service: light.turn_off
        target:
          entity_id: light.kitchen

Given I implement and test it, is this something which would be accepted as a PR?

Is there another way to solve this?

Thanks!

[balloob]

Yeah seems fine. I wonder if we should name it parse_iso8601_duration or something (not sure what we do for iso dates). Would the output be a timedelta? Not sure if you need isodate, it seems a bit overkill for 1 method? Can we cherry-pick it or is it already part of dateutil which we already install?

[eifinger]

Unfortunately dateutil does not have support for durations. I think the most appropiate way would be to cherrypick the needed 30-40 lines (here, here and here).

The output of this function would indeed be a timedelta

[eifinger]

I will implement, test and put up a PR in the following days.

[eifinger]

home-assistant/core#71801

[frenck]

We have logic for that already that could be reused? The exact logic we use to validate time periods can be used for a template filter?

[eifinger]

Could you clarify which logic you have in mind? I looked at dt and could not find anything related to ISO8601 duration parsing and the time_period_str function deals with periods instead of durations.

[frenck]

Extend and reuse time() in helpers/config_validation.py

[balloob]

ISO8601 durations are not the same as 'time'. They look like PT10M (This one means: Period, Time part, 10 minutes)