Align custom integration unit handling with core integration

- Move unit resolution to _native_unit_of_measurement in base entity
- Resolve COST units from HA currency in base helper
- Set native unit in async_added_to_hass for sensor/number
- Add NumberDeviceClass.MONETARY mapping for MetricType.COST

Author: tomer-w

custom_components/victron_mqtt/entity.py

@@ -69,9 +69,12 @@ def __init__(
             metric.generic_short_id not in ENTITIES_DISABLE_BY_DEFAULT
         )
 
-    def _set_unit_translation(self) -> None:
+    def _native_unit_of_measurement(self) -> str | None:
+        if self._metric.metric_type == MetricType.COST:
+            return self.hass.config.currency
+
         unit_of_measurement = self._metric.unit_of_measurement
-        # We need to set the _attr_native_unit_of_measurement in three cases:
+        # We need to provide a native unit in three cases:
         if (
             # 1. Special units which will never need a translation and therefore will not be included in the translation file.
             unit_of_measurement in SPECIAL_NATIVE_UNITS
@@ -85,7 +88,9 @@ def _set_unit_translation(self) -> None:
             # entry, so we must set the unit programmatically.
             or self._metric.metric_type == MetricType.DYNAMIC
         ):
-            self._attr_native_unit_of_measurement = unit_of_measurement
+            return unit_of_measurement
+
+        return None
 
     @callback
     @abstractmethod

custom_components/victron_mqtt/number.py

@@ -33,6 +33,7 @@
     MetricType.PRESSURE: NumberDeviceClass.PRESSURE,
     MetricType.DISTANCE: NumberDeviceClass.DISTANCE,
     MetricType.POWER_FACTOR: NumberDeviceClass.POWER_FACTOR,
+    MetricType.COST: NumberDeviceClass.MONETARY,
     MetricType.SPEED: NumberDeviceClass.SPEED,
     MetricType.LIQUID_VOLUME: NumberDeviceClass.VOLUME_STORAGE,
     MetricType.DURATION: NumberDeviceClass.DURATION,
@@ -91,8 +92,8 @@ def __init__(
             simple_naming,
             installation_id,
         )
+        self._attr_native_unit_of_measurement = None
         self._attr_device_class = METRIC_TYPE_TO_DEVICE_CLASS.get(metric.metric_type)
-        self._set_unit_translation()
         self._attr_native_value = metric.value
         if metric.min_value is not None:
             self._attr_native_min_value = metric.min_value
@@ -106,6 +107,11 @@ def _on_update_cb(self, value: Any) -> None:
         self._attr_native_value = value
         self.async_write_ha_state()
 
+    async def async_added_to_hass(self) -> None:
+        """Run when entity about to be added to hass."""
+        self._attr_native_unit_of_measurement = self._native_unit_of_measurement()
+        await super().async_added_to_hass()
+
     async def async_set_native_value(self, value: float) -> None:
         """Set a new value."""
         if TYPE_CHECKING:

custom_components/victron_mqtt/sensor.py

@@ -113,9 +113,6 @@ def __init__(
             self._attr_state_class = METRIC_NATURE_TO_STATE_CLASS.get(
                 metric.metric_nature
             )
-        # MONETARY uses hass.config.currency which isn't available in __init__.
-        if self._attr_device_class != SensorDeviceClass.MONETARY:
-            self._set_unit_translation()
         self._attr_native_value = VictronSensor._normalize_value(metric.value)
 
     @callback
@@ -135,8 +132,7 @@ def _normalize_value(value: Any) -> Any:
 
     async def async_added_to_hass(self) -> None:
         """Restore persistent state for FormulaMetric energy sensors."""
-        if self._attr_device_class == SensorDeviceClass.MONETARY:
-            self._attr_native_unit_of_measurement = self.hass.config.currency
+        self._attr_native_unit_of_measurement = self._native_unit_of_measurement()
 
         # Only restore for cumulative FormulaMetric sensors (TOTAL / TOTAL_INCREASING).
         # These metrics start from 0 on each HA restart, so we restore the