HA Entity Display Utility (src/utils/ha-entity-display.js)

Single source of truth for all HA i18n/locale-aware formatting in LCARdS.

Purpose

Delegates entirely to the hass.format* public API family (stable since HA 2024.4+, guaranteed on the LCARdS 2026.3.0 minimum). All cards, editors, charts, and datasource utilities must import from this module — never call hass.format* directly elsewhere.

Why a Centralized Utility?

• Single integration point: If the HA API changes, only this file needs updating.
• Safe fallbacks: All exports include graceful fallbacks so a missing or erroring hass method never reaches the render pipeline as undefined or null.
• No custom translation tables: All translation is delegated to HA — LCARdS does not ship locale JSON or string maps.

Exports

Export	Description
haFormatState(hass, stateObj)	HA-translated display state (e.g. "on" → "Open" for a door sensor)
haFormatEntityName(hass, stateObj)	HA-formatted friendly name
haFormatAttrValue(hass, stateObj, key)	HA-formatted attribute value (e.g. battery_level 80 → "80 %")
haFormatAttrName(hass, stateObj, key)	HA-formatted attribute name (e.g. "battery_level" → "Battery Level")
haFormatStateParts(hass, stateObj)	State as ToParts array: [{value:'23.5'},{value:'°C'}]
haFormatAttrParts(hass, stateObj, key)	Attribute as ToParts array
haFormatNumber(hass, value, opts)	Locale-aware number formatting — respects hass.locale.number_format (comma_decimal, decimal_comma, space_comma, quote_decimal, none, system) and language. Mirrors HA's numberFormatToLocale().
haFormatDate(hass, ts, opts)	Locale-aware date formatting — respects hass.locale.language, time_format (12/24h), and date_format (DMY/MDY/YMD) via formatToParts() reordering. Mirrors HA's formatDateNumeric().
joinParts(parts)	Join a ToParts array to a single display string
extractUnit(parts)	Extract the unit portion from a ToParts array

LCARdSCard Convenience Methods

LCARdSCard exposes protected wrapper methods for cards to use directly without importing the utility:

this._getStateDisplay(entity?)        // → haFormatState
this._getEntityName(entity?)          // → haFormatEntityName
this._getAttributeDisplay(key, entity?) // → haFormatAttrValue
this._getAttributeName(key, entity?)  // → haFormatAttrName

All default to this._entity when no entity is provided.

Important Constraints

• State classification must use raw values. haFormatState returns a display string (e.g. "Open") — never use it for _classifyEntityState() or icon resolution. Those must always use the raw entity.state value ("on", "off", etc.).
• JS templates are unaffected. [[[...]]] templates receive raw entity objects and can call hass.formatEntityState(entity) directly.
• Jinja2 templates are server-evaluated and unaffected.