leak-detector-notifier.yaml

blueprint:
  name: Leak detection & notifier
  description: Send a notification when any configured moisture sensor becomes moist
  domain: automation
  input:
    notify_device:
      name: Notify device
      description: "The device where the notification should be sent to."
      selector:
        device:
          integration: mobile_app

trigger:
  - event_data: {}
    event_type: state_changed
    platform: event

condition:
  - condition: template
    value_template: '{{ trigger.event.data.new_state.attributes.device_class == "moisture" }}'
  - condition: template
    value_template: '{{ trigger.event.data.new_state.state == "on" }}'

action:
  domain: mobile_app
  type: notify
  device_id: !input notify_device
  message: "{{ trigger.event.data.new_state.attributes.friendly_name }} has detected a leak."
  title: "Leak detected!"

mode: single

life (and money) saver! Just trying to understand class hierarchy via haas documentation was rough. I do have a question. @bbbenji's code would trigger at every event to match against the AND conditions listed under condition. I'm rather unfamiliar with the trigger framework (reading up on it) but would it be possible to only trigger when device_class == "moisture" and then apply condition of new_state.state == "on"?
Thank you for this effort!

Very new to blueprints, I love this - but I want to be able to exclude a few leak sensors that I want to use for a different purpose. Any pointers on how I'd go about adding an exclude list? I see how to declare them here: https://gist.github.com/sbyx/1f6f434f0903b872b84c4302637d0890 but not sure how I'd eventually use that list.

Getting an error recently: Template variable error: 'None' has no attribute 'attributes'
when rendering '{{ trigger.event.data.new_state.attributes.device_class == "moisture" }}'

chatgpt tells me:
The error 'None' has no attribute 'attributes' happens when trigger.event.data.new_state is None. This can happen if a sensor is deleted, unavailable, or for some reason the event doesn’t include a new_state.

In Home Assistant, a safe way to handle this is to check that new_state exists before accessing its attributes. You can change your condition to:

and proposes this fix

- condition: template value_template: > {% if trigger.event.data.new_state %} {{ trigger.event.data.new_state.attributes.device_class == 'moisture' }} {% else %} false {% endif %}