home-assistant.github.io/source/getting-started/templating.markdown

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

The template helper enables one to mathematically manipulate values and use variables to extract values from JSON.

For a complete overview, check the Jinja2 Template documentation.

{% linkable_title states variable %}

The template support has a special states variable:

• 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 state object for sensor.temperature

Example templates and what they could result in:

Template	Output
{{ states.device_tracker.paulus.state }}	home
{% for state in states.sensor %}{{ state.entity_id }}={{ state.state }}, {% endfor %}	senor.thermostat=24, sensor.humidity=40,

{% linkable_title Mathematical functions %}

The mathematical methods convert strings to numbers automatically before they are doing their job. This could be useful if you recieve data in the wrong unit of measurement and want to convert it.

Method	description
multiply(x)	Multiplies the value with x
round(x)	Maximau number x of decimal places for the value

A sample entry in your configuration.yaml file for a sensor could look like this:

# Example configuration.yaml entry
sensor:
  platform: dweet
  device: temp-sensor012
  value_template: '{{ value_json.temperature | multiply(1.02) | round(2) }}'
  unit_of_measurement: "°C"