Example Function "is_valid_entity" verifies given entity_ids if they are exposed, visible, etc.

[jleinenbach]

- spec:
    name: is_valid_entity
    description: >
      Checks if a given entity_id is exposed, verifies its configuration and visibility.
    parameters:
      type: object
      properties:
        entity_id:
          type: string
          description: The entity_id of the Home Assistant entity to check.
      required:
        - entity_id
  function:
    type: composite
    sequence:
      - type: sqlite
        query: >-
          {% if entity_id is defined and entity_id %}
            SELECT '{{ is_exposed(entity_id) }}' AS result;
          {% else %}
            SELECT 'undefined' AS result;
          {% endif %}
        response_variable: exposure_status
      - type: template
        value_template: >-
          {%- if entity_id is defined and entity_id %}
            {%- set entity_check = states[entity_id] %}
            {%- if entity_check %}
              {%- if entity_check.state not in ['unknown', 'unavailable'] %}
                {%- set exposure_info = 'Is exposed: ' ~ exposure_status %}
                {%- set config_info = ' Has config entry.' if config_entry_id(entity_id) else ' No config entry.' %}
                {%- set hidden_info = ' Is hidden.' if is_hidden_entity(entity_id) else ' Is not hidden.' %}
                {{ exposure_info ~ config_info ~ hidden_info }}
                {%- if has_value(entity_id) %}
                  {{ ' ' ~ entity_id ~ ' has a valid value.' }}
                {%- else %}
                  {{ ' ' ~ entity_id ~ ' does not have a valid value.' }}
                {%- endif %}
              {%- else %}
                {{ 'Entity state is ' ~ entity_check.state ~ ', cannot determine exposure reliably.' }}
              {%- endif %}
            {%- else %}
              {{ 'The specified entity_id ' ~ entity_id ~ ' does not exist. Use a search function to get the correct entity_id.' }}
            {%- endif %}
          {%- else %}
            {{ 'The specified entity_id is invalid or not provided. Please provide a valid entity_id.' }}
          {%- endif %}