v3_button_purifier:
  template: v3_button
  state_display: |
    [[[
      if (entity.state === 'off') { return 'Off'; }
      if (!entity.attributes.preset_mode) { return 'Unknown preset'; }
      return entity.attributes.preset_mode.charAt(0).toUpperCase() + entity.attributes.preset_mode.slice(1);
    ]]]
  variables:
    value_has_error: |
      [[[
        return states['binary_sensor.purifier_filter_needs_change'].state === 'on';
      ]]]