home-assistant.io/source/_docs/configuration/templating.markdown

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layout	title	description	date	sidebar	comments	sharing	footer	redirect_from
page	Templating	Instructions on how to use the templating feature of Home Assistant.	2015-12-12 12:00	true	false	true	true	/topics/templating/

This is an advanced feature of Home Assistant. You'll need a basic understanding of the following things:

• Home Assistant architecture, especially states.
• State object

Templating is a powerful feature in Home Assistant that allows the user control over information that is going into and out of the system. It is used for:

• Formatting outgoing messages in, for example, the notify platforms and alexa component.
• Process incoming data from sources that provide raw data, like MQTT, rest sensor or the command_line sensor.
• Automation Templating.

{% linkable_title Building templates %}

Templating in Home Assistant is powered by the Jinja2 templating engine. This means that we are using their syntax and make some custom Home Assistant variables available to templates during rendering. We will not go over the basics of the syntax, as Jinja2 does a lot better job at this in their Jinja2 documentation.

The frontend has a template editor developer tool to help develop and debug templates.

Templates can get big pretty fast. To keep a clear overview, consider using YAML multiline strings to define your templates:

{% raw %}

script:
  msg_who_is_home:
    sequence:
      - service: notify.notify
        data_template:
          message: >
            {% if is_state('device_tracker.paulus', 'home') %}
              Ha, Paulus is home!
            {% else %}
              Paulus is at {{ states('device_tracker.paulus') }}.
            {% endif %}

{% endraw %}

Jinja2 supports a wide variety of operations:

• Mathematical operation
• Comparisons
• Logic

{% linkable_title Home Assistant template extensions %}

Home Assistant adds extensions to allow templates to access all of the current states:

• Iterating states will yield each state sorted alphabetically by entity ID.
• Iterating states.domain will yield each state of that domain sorted alphabetically by entity ID.
• states.sensor.temperature returns the state object for sensor.temperature.
• states('device_tracker.paulus') will return the state string (not the object) of the given entity or unknown if it doesn't exist.
• is_state('device_tracker.paulus', 'home') will test if the given entity is the specified state.
• state_attr('device_tracker.paulus', 'battery') will return the value of the attribute or None if it doesn't exist.
• is_state_attr('device_tracker.paulus', 'battery', 40) will test if the given entity attribute is the specified state (in this case, a numeric value).
• now() will be rendered as current time in your time zone.
  • For specific values: now().second, now().minute, now().hour, now().day, now().month, now().year, now().weekday() and now().isoweekday()
• utcnow() will be rendered as UTC time.
  • For specific values: utcnow().second, utcnow().minute, utcnow().hour, utcnow().day, utcnow().month, utcnow().year, utcnow().weekday() and utcnow().isoweekday().
• as_timestamp() will convert datetime object or string to UNIX timestamp
• distance() will measure the distance in kilometers between home, entity, coordinates.
• closest() will find the closest entity.
• float will format the output as float.
• strptime(string, format) will parse a string to a datetime based on a format.
• log(value, base) will take the logarithm of the input. When the base is omitted, it defaults to e - the natural logarithm. Can also be used as a filter.
• sin(value) will return the sine of the input. Can be used as a filter.
• cos(value) will return the cosine of the input. Can be used as a filter.
• tan(value) will return the tangent of the input. Can be used as a filter.
• sqrt(value) will return the square root of the input. Can be used as a filter.
• e mathematical constant, approximately 2.71828.
• pi mathematical constant, approximately 3.14159.
• tau mathematical constant, approximately 6.28318.
• Filter round(x) will convert the input to a number and round it to x decimals.
• Filter timestamp_local will convert an UNIX timestamp to local time/data.
• Filter timestamp_utc will convert an UNIX timestamp to UTC time/data.
• Filter timestamp_custom(format_string, local_boolean) will convert an UNIX timestamp to a custom format, the use of a local timestamp is default, supporting Python format options.
• Filter max will obtain the largest item in a sequence.
• Filter min will obtain the smallest item in a sequence.
• Filter regex_match(string, find, ignorecase=FALSE) will match the find expression at the beginning of the string using regex.
• Filter regex_search(string, find, ignorecase=FALSE) will match the find expression anywhere in the string using regex.
• Filter regex_replace(string, find='', replace='', ignorecase=False) will replace the find expression with the replace string using regex.
• Filter regex_findall_index(string, find='', index=0, ignorecase=False) will find all regex matches of find in string and return the match at index (findall returns an array of matches).
• Filter bitwise_and(value_one, value_two) perform a bitwise and(&) operation with two values.
• Filter bitwise_or(value_one, value_two) perform a bitwise or(|) operation with two values.
• Filter base64_encode convert given value to a Base64 encoded string.
• Filter base64_decode convert given Base64 value to a regulary string.
• Filter ordinal convert a number into a speakable ordinal text.

If your template uses an `entity_id` that begins with a number (example: `states.device_tracker.2008_gmc`) you must use a bracket syntax to avoid errors caused by rendering the `entity_id` improperly. In the example given, the correct syntax for the device tracker would be: `states.device_tracker['2008_gmc']`

{% linkable_title Templates using now() %}

Rendering templates with time (`now()`) is dangerous as updates only trigger templates in sensors based on entity state changes.

{% linkable_title Priority of operators %}

The default priority of operators is that the filter (|) has priority over everything except brackets. This means that:

{% raw %}

{{ states('sensor.temperature') | float / 10 | round(2) }}

{% endraw %}

Would round 10 to 2 decimal places, then divide states('sensor.temperature') by that.

{% linkable_title Home Assistant template extensions %}

In templates, besides the normal state object methods and properties, there are also some extra things available:

• states.sensor.temperature.state_with_unit will print the state of the entity and, if available, the unit.

{% linkable_title Examples %}

To test a template, go to the template developer tools, create your template in the Template editor and check the results on the right.

{% linkable_title States %}

The next two statements result in same value if state exists. The second one will result in an error if state does not exist.

{% raw %}

{{ states('device_tracker.paulus') }}
{{ states.device_tracker.paulus.state }}

{% endraw %}

{% linkable_title Attributes %}

Print an attribute if state is defined. Both will return the same thing but the last one you can specify entity_id from a variable.

{% raw %}

{% if states.device_tracker.paulus %}
  {{ state_attr('device_tracker.paulus', 'battery') }}
{% else %}
  ??
{% endif %}

{% endraw %}

With strings

{% raw %}

{% set tracker_name = "paulus"%}

{% if states("device_tracker." + tracker_name) != "unknown" %}
  {{ state_attr("device_tracker." + tracker_name, "battery")}}
{% else %}
  ??
{% endif %}

{% endraw %}

{% linkable_title Sensor states %}

Print out a list of all the sensor states.

{% raw %}

{% for state in states.sensor %}
  {{ state.entity_id }}={{ state.state }},
{% endfor %}

{% if is_state('device_tracker.paulus', 'home') %}
  Ha, Paulus is home!
{% else %}
  Paulus is at {{ states('device_tracker.paulus') }}.
{% endif %}

{{ states('sensor.temperature') | float + 1 }}

{{ (states('sensor.temperature') | float * 10) | round(2) }}

{% if states('sensor.temperature') | float > 20 %}
  It is warm!
{%endif %}

{{ as_timestamp(states.binary_sensor.garage_door.last_changed) }}

{{ as_timestamp(now()) - as_timestamp(states.binary_sensor.garage_door.last_changed) }}

{% endraw %}

{% linkable_title Distance examples %}

If only 1 location is passed in, Home Assistant will measure the distance from home.

{% raw %}

Using Lat Lng coordinates: {{ distance(123.45, 123.45) }}

Using State: {{ distance(states.device_tracker.paulus) }}

These can also be combined in any combination:
{{ distance(123.45, 123.45, 'device_tracker.paulus') }}
{{ distance('device_tracker.anne_therese', 'device_tracker.paulus') }}

{% endraw %}

{% linkable_title Closest examples %}

Find entities closest to the Home Assistant location:

{% raw %}

Query all entities: {{ closest(states) }}
Query all entities of a specific domain: {{ closest('states.device_tracker') }}
Query all entities in group.children: {{ closest('group.children') }}
Query all entities in group.children: {{ closest(states.group.children) }}

{% endraw %}

Find entities closest to a coordinate or another entity. All previous arguments still apply for 2nd argument.

{% raw %}

Closest to a coordinate: {{ closest(23.456, 23.456, 'group.children') }}
Closest to an entity: {{ closest('zone.school', 'group.children') }}
Closest to an entity: {{ closest(states.zone.school, 'group.children') }}

{% endraw %}

{% linkable_title Combined %}

Since closest returns a state, we can combine it with distance too.

{% raw %}

{{ closest(states).name }} is {{ distance(closest(states)) }} kilometers away.

{% endraw %}

{% linkable_title Processing incoming data %}

The other part of templating is processing incoming data. It will allow you to modify incoming data and extract only the data you care about. This will work only for platforms and components that mentioned support for this in their documentation.

It depends per component or platform, but it is common to be able to define a template using the value_template configuration key. When a new value arrives, your template will be rendered while having access to the following values on top of the usual Home Assistant extensions:

Variable	Description
value	The incoming value.
value_json	The incoming value parsed as JSON.

This means that if the incoming values looks like the sample below:

{
  "on": "true",
  "temp": 21
}

The template for on would be:

{% raw %}

'{{value_json.on}}'

{% endraw %}

Nested JSON in a response is supported as well:

{
  "sensor": {
    "type": "air",
    "id": "12345"
  },
  "values": {
    "temp": 26.09,
    "hum": 56.73,
  }
}

Just use the "Square bracket notation" to get the value.

{% raw %}

'{{ value_json['values']['temp'] }}'

{% endraw %}

The following overview contains a couple of options to get the needed values:

# Incoming value:
{"primes": [2, 3, 5, 7, 11, 13]}

# Extract third prime number
{% raw %}{{ value_json.primes[2] }}{% endraw %}

# Format output
{% raw %}{{ "%+.1f" | value_json }}{% endraw %}

# Math
{% raw %}{{ value_json | float * 1024 }}{% endraw %}
{% raw %}{{ float(value_json) * (2**10) }}{% endraw %}
{% raw %}{{ value_json | log }}{% endraw %}
{% raw %}{{ log(1000, 10) }}{% endraw %}
{% raw %}{{ sin(pi / 2) }}{% endraw %}
{% raw %}{{ cos(tau) }}{% endraw %}
{% raw %}{{ tan(pi) }}{% endraw %}
{% raw %}{{ sqrt(e) }}{% endraw %}

# Timestamps
{% raw %}{{ value_json.tst | timestamp_local }}{% endraw %}
{% raw %}{{ value_json.tst | timestamp_utc }}{% endraw %}
{% raw %}{{ value_json.tst | timestamp_custom('%Y' True) }}{% endraw %}

To evaluate a response, go to the template developer tools, create your output into "Template", and check the result.

{% raw %}

{% set value_json=
    {"name":"Outside",
	 "device":"weather-ha",
     "data":
	    {"temp":"24C",
		 "hum":"35%"
		 }	}%}

{{value_json.data.hum[:-1]}}

{% endraw %}