Unavailable Devices Sensor

unavailable_devices.yaml

    
###----------------------------------------------------------------------------------------------------------------------
###
###           Unavailable Devices Sensor
###           --------------------------
###
### 05-Feb-2024 | Andy Symons | created
### 14-Feb-2024 | Andy Symons | 'button' and 'update' added to the domain lists
###
### The sensor provides lists related to real devices, not internal entities, helpers, automations etc.,
### Entities with state 'unknown' are not counted, because it is possible for a device to have a sub-entity that is
###    unknown while the device itself is available.
###
### The STATE simply gives the count of unavailable devices.
### The long results have to be attributes because the state cannot contain more than 255 characters:
###   ATTRIBUTE 'entity_id_list' (debug aid) contains a list of unavailable entities using their entity ids, which may or may not have been set by the user.
###   ATTRIBUTE 'entity_name_list' (debug aid) contains a list of unavailable entities using their friendly names as assigned by the user.
###   ATTRIBUTE 'device_name_list (the main output) contains a list of the devices that are unavailable, which is to say having one or more entities that are unavailable,
###      using their friendly names as assigned by the user.
###
###----------------------------------------------------------------------------------------------------------------------

template:
  - sensor:
      name: "Unavailable Devices"
      unique_id: unavailable_devices
      icon: "{{ iif(states(this.entity_id)|int(-1) > 0,'mdi:alert-circle','mdi:check-circle') }}"
      state_class: measurement
      unit_of_measurement: devices

      # The sensor state is the count of unavailable devices
      state: >
          {{ states
          | selectattr('domain','in', ['binary_sensor', 'button', 'climate', 'light', 'sensor', 'switch', 'update'] ) 
          | selectattr('state', 'in', ['unavailable'])
          | map(attribute='entity_id')
          | map('device_attr', 'name_by_user') 
          | reject('match', 'None')
          | unique
          | list 
          | count
          }}

      attributes:
        ## DEBUG AID: A list of unavailable entities using their entity ids (which mnay or may not have been set by the user).
        entity_id_list: >-
          {{ states
          | selectattr('domain','in', ['binary_sensor', 'button', 'climate', 'light', 'sensor', 'switch', 'update'] )
          | selectattr('state', 'in', ['unavailable'])
          | map(attribute='entity_id')
          | reject('match', 'None')
          | list 
          | sort 
          | unique
          | join('\n')
          }}

        ## DEBUG AID: A list of unavailable entities using their friendly names as assigned by the user.
        entity_name_list: >-
          {{ states
          | selectattr('domain','in', ['binary_sensor', 'button', 'climate', 'light', 'sensor', 'switch', 'update'] ) 
          | selectattr('state', 'in', ['unavailable'])
          | map(attribute='entity_id')
          | map('state_attr', 'friendly_name') 
          | reject('match', 'None')
          | list 
          | sort 
          | unique
          | join('\n')
          }}

        ## MAIN OUTPUT: A list of the devices that are unavailable, using their friendly names as assigned by the user.
        device_name_list: >-
          {{ states
          | selectattr('domain','in', ['binary_sensor', 'button', 'climate', 'light', 'sensor', 'switch', 'update'] ) 
          | selectattr('state', 'in', ['unavailable'])
          | map(attribute='entity_id')
          | map('device_attr', 'name_by_user') 
          | reject('match', 'None')
          | list 
          | sort 
          | unique
          | join('\n')
          }}

# HOW THE ATTRIBUTE TEMPLATES WORK
#  -- Taking device_name_list as an example...
#
# {{ states                                                        -- all the states (entities) in the system
#    | selectattr('domain','in',['binary_sensor', 'climate', etc.  -- filter only the entities for real devices
#    | selectattr('state', 'in', ['unavailable'])                  -- filter only entities that are unavailable
#    | map(attribute='entity_id')                                  -- get the entity id from the record
#    | map('device_attr', 'name_by_user')                          -- map the entity id onto the device name
#    | reject('match', 'None')                                     -- take out names 'None' (meaning there is no name, so not a device)
#    | unique                                                      -- take out duplicates (devices usually have several entities)
#    | list                                                        -- make into a list (in the template sense)
#    | sort                                                        -- put them in alphabetical order
#    | join('\n')                                                  -- take out extraneous punctuation for a tidy output
#  }}

To install

1. If you do not already have a templates.yaml file
   • create the file /config/templates.yaml
   • in /config/configuration.yaml insert the line template: !include templates.yaml
2. Copy the code from unavailable_devices.yaml and paste it into /config/templates.yaml
3. Reload the configuration to activate the sensor
4. If it does not work, clear the log file, reload the configuration again, then examine the log file for error messages