Templates

LCARdS cards support dynamic content through four template syntaxes. You can mix them freely in most string values.

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Syntax Overview

1. Token Templates {...}

Simple substitutions for entity state, attributes, theme values, and data source values.

text:
  label:
    content: "{entity.state}"                          # Entity state
  sublabel:
    content: "{entity.attributes.brightness}"          # Attribute
  other_entity:
    content: "{states.sensor.outdoor_temp.state}"      # A DIFFERENT entity's state
  title:
    content: "{theme:colors.text.onDark}"              # Theme token
  reading:
    content: "{ds:temp}"                              # DataSource: HA-native (locale-formatted + unit)

Available tokens:

Token	Value
{entity.state}	Current entity state string
{entity.attributes.NAME}	Any entity attribute by name
{states.domain.object_id.state}	State of a different entity, referenced by full entity ID
{states.domain.object_id.attributes.NAME}	Attribute NAME of a different entity
{config.NAME}	A value from this card's own config
{variables.NAME}	A value from config.variables
{hass.user.name}	The current Home Assistant user's name
{theme:token.path}	Theme token value: see Themes

For DataSource values ({ds:...}), see Section 4 below.

NOTE

This single-brace {...} syntax is an LCARdS-specific shorthand, not a Home Assistant or Jinja2 convention; it exists because it resolves synchronously (no network round trip), which some render paths require. If you already know HA's Jinja2 templating from automations or other cards, reach for Jinja2 templates ({{ }}, real double braces) instead; it's the actual HA template engine and supports everything you already know (states(), state_attr(), filters, etc.). Use single-brace tokens when you specifically need the synchronous fast path.

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2. JavaScript Templates [[[...]]]

For any logic or calculation. Return the final value.

text:
  label:
    content: "[[[return entity.state === 'on' ? 'Active' : 'Inactive']]]"

  brightness:
    content: "[[[return Math.round(entity.attributes.brightness / 255 * 100) + '%']]]"

  climate_status:
    content: >
      [[[
        const state = entity.state;
        const temp = entity.attributes.current_temperature;
        return state === 'heating' ? `Heating to ${entity.attributes.temperature}°` : `${temp}°`;
      ]]]

Available context:

Variable	Type	Contents
entity	object	Current entity state: entity.state, entity.attributes.*, entity.entity_id, entity.last_changed
hass	object	Full Home Assistant object: hass.states, hass.services, hass.user, hass.themes
states	object	Shorthand for hass.states; a different entity's state object, e.g. states['sensor.outdoor_temp'].state
config	object	This card's full config
variables	object	config.variables
theme	object	Current theme token tree
user	object	Current Home Assistant user (hass.user)

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3. Jinja2 Templates {{...}}

Evaluated server-side by Home Assistant. Supports all HA template functions.

text:
  label:
    content: "{{ states('sensor.temperature') }}°C"
  status:
    content: "{% if is_state('light.kitchen', 'on') %}On{% else %}Off{% endif %}"
  diff:
    content: "{{ (states('sensor.temp_inside')|float - states('sensor.temp_outside')|float)|round(1) }}°"

NOTE

Jinja2 templates are evaluated asynchronously by HA. There may be a brief delay before values appear after a page load.

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4. Data Source Templates {ds:...} / {datasource:...}

For values from a named data source. The {ds:name} shorthand and the {datasource:name} long form are equivalent.

No format specifier → HA-native display: locale-formatted number + unit from entity metadata (e.g. 4,73 °C). Equivalent to HA's haFormatEntityState().

With a format specifier → you own the output. The number is formatted to the spec and returned with no auto-unit; append any suffix you want.

Specifier	Example	Result
(none)	{ds:temp}	4,73 °C: HA-native, locale-formatted + unit
:.Nf	{ds:temp:.1f}	4,7: N decimal places, no unit
:int	{ds:temp:int}	5: rounded integer, no unit
:.N%	{ds:progress:.0%}	75%: percentage
:str	{ds:label:str}	raw string coercion

To access a specific processor buffer, use the long form with a dotted path:

data_sources:
  temp:
    entity: sensor.temperature
    processing:
      f: { type: convert_unit, from: c, to: f }

text:
  value:
    content: "{ds:temp}"                    # HA-native: "4,73 °C"
    # content: "{ds:temp:.2f} °C"           # explicit precision: "4,73 °C" (no auto-unit)
    # content: "{datasource:temp.f:.0f}"    # processor buffer: "76" (Fahrenheit, no unit)

See Data Sources for declaring and configuring sources.

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Where Templates Work

Templates are evaluated in most string-valued config properties:

• text.*.content: label text
• style.*: style values, including colours and token references
• tap_action.service_data.*: action parameters
• tap_action.navigation_path: dashboard path
• tap_action.url_path: URL
• icon: icon name
• rules.*.when.*.condition: rule condition expressions (JS and Jinja2); see Rule Conditions
• Slider card style.ranges[].value / .min / .max: marker/band positions (JS, token, and DataSource only; no Jinja2, since these resolve synchronously on every state update) and style.ranges[].label.text: marker caption text (all 4 types, including Jinja2); see Slider Card

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Template Evaluation Order

When a value could match multiple syntaxes, evaluation proceeds in this order:

1. [[[...]]]: JavaScript (evaluated first)
2. {token}: Token substitution
3. {ds:...} / {datasource:...}: data source
4. {{...}}: Jinja2 (HA server-evaluated, async)

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Entity Tracking & Reactivity

LCARdS re-renders a card (and re-evaluates all its templates) whenever a relevant entity changes state.

Automatic tracking

Entity references in Jinja2 templates are detected automatically, no extra config needed:

text:
  label:
    content: "{{ states('sensor.temperature') }}°C"   # ✅ auto-tracked
  status:
    content: >-
      {% if is_state('binary_sensor.motion', 'on') %}
        Motion detected
      {% endif %}                                       # ✅ sensor tracked automatically

The following Jinja2 call patterns are scanned: states(), state_attr(), is_state(), is_state_attr(), has_value()

Manual tracking with triggers_update

JavaScript templates ([[[...]]]) are opaque to static analysis; LCARdS cannot know which entities they reference. Declare them explicitly:

type: custom:lcards-button
entity: light.kitchen
triggers_update:
  - binary_sensor.desk_sensor_motion
  - sensor.toronto_temperature

text:
  label:
    content: |
      [[[
        const motion = hass.states['binary_sensor.desk_sensor_motion']?.state;
        const temp   = hass.states['sensor.toronto_temperature']?.state;
        return motion === 'on' ? `Motion (${temp}°)` : 'Clear';
      ]]]

triggers_update also works for token or data source templates whose entity IDs are assembled dynamically and cannot be inferred at parse time.

NOTE

triggers_update is additive: the card's primary entity is always tracked regardless.