Home Assistant Blueprint: Link Multiple Switches v1.0.1

link_multiple_switches.yaml

blueprint:
  name: Link Multiple Switches
  description: |
    ## Link multiple switches together v1.0.1

    Select multiple switch entities to link their on/off state.  If any selected switch entity is turned on or off, the other selected entities will be sent a matching on or off command.

    Requires Home Assistant 2022.5.0 or newer.
    Credit to @adchevrier for the initial blueprint: https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010
    Credit to @Hebus for this fantastic template: https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010/38
  domain: automation
  homeassistant:
    min_version: 2022.5.0
  input:
    switches:
      name: Switch Entites
      selector:
        entity:
          domain: switch
          multiple: true
  source_url: https://gist.github.com/aderusha/4f25658dbb855675b5b5ccf296fd801b

mode: queued
max_exceeded: silent

variables:
  switches: !input 'switches'

trigger:
- platform: state
  entity_id: !input 'switches'

condition:
- condition: template
  value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
- condition: template
  value_template: '{{ trigger.to_state.state != "unknown" }}'
- condition: template
  value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'

action:
- service: homeassistant.turn_{{ trigger.to_state.state }}
  target:
    entity_id: '{{ expand(switches) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'

The last condition for me causes a 30% of failures in the sync of the entities. I think is not usefull and when removed everything works fine becasue the save exist if on the state

Could someone explain what the last condition meant to do? I can't understand the intent..

Could someone explain what the last condition meant to do? I can't understand the intent..

It looks like the last condition is intended to prevent recursion (i.e. infinite toggling of the switch state). The effectiveness of this condition will depend on the to_state's context parent ID.