Helpers

The cbc_helpers addon provides small helper functions through the variables object. It is inherited by cbcjs, so it is available on most templates already. If you're creating your own custom template from scratch and want to use these helpers, include cbc_helpers in the template list.

These helpers are most useful when you have a main entity with related child entities using Home Assistant's usual object ID pattern. For example, a smart plug might use switch.power_plug as the main entity and expose related sensors like sensor.power_plug_voltage, sensor.power_plug_current, and sensor.power_plug_power.

CBC Helpers (cbc_helpers)

Helper Functions

Helper	Returns	Description
$parentId(removal)	String	Returns the current entity object ID without the domain. Optionally removes an extra string from the object ID.
$childEntityId(name, domain, removal)	String	Builds a related child entity ID from the current entity object ID, child name, and optional domain.

$parentId(removal)

Gets the current entity object ID by removing the domain from entity.entity_id. If you pass removal, that value is also removed from the object ID before it is returned.

Parameter	Value Type	Default	Description
removal	String	''	Optional text to remove from the current entity object ID.

variables.$parentId(removal);

For a card using entity: switch.power_plug:

variables.$parentId(); // power_plug

For a card using entity: switch.power_plug_switch:

variables.$parentId('_switch'); // power_plug

$childEntityId(name, domain, removal)

Builds a related child entity ID from the current entity. The helper removes the current entity domain, optionally removes extra text from the object ID, then appends _<name>.

Parameter	Value Type	Default	Description
name	String		Child entity suffix to append to the parent object ID. If empty, the helper returns an empty string.
domain	String	sensor	Domain for the generated child entity ID.
removal	String	''	Optional text to remove from the current entity object ID before appending the child suffix.

variables.$childEntityId(name, domain, removal);

For a card using entity: switch.power_plug:

variables.$childEntityId('voltage'); // sensor.power_plug_voltage
variables.$childEntityId('enable', 'input_boolean'); // input_boolean.power_plug_enable

For a card using entity: switch.power_plug_switch:

variables.$childEntityId('power', 'sensor', '_switch'); // sensor.power_plug_power

Helpers Example YAML

See the YAML...

type: custom:button-card
template: entity
entity: switch.power_plug
name: Power Plug
variables:
  attributes:
    - icon: mdi:flash
      entity: "[[[ return variables.$childEntityId('power'); ]]]"
    - icon: mdi:sine-wave
      entity: "[[[ return variables.$childEntityId('voltage'); ]]]"