esphome-docs/components/text_sensor/index.rst
Otto Winter d23b7e5736
Updates
2019-05-15 11:49:05 +02:00

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Text Sensor Component
=====================
.. seo::
:description: Instructions for setting up text sensors that represent their state as a string of text.
:image: folder-open.png
Text sensors are a lot like normal :doc:`sensors </components/sensor/index>`.
But where the "normal" sensors only represent sensors that output **numbers**, this
component can represent any *text*.
.. _config-text_sensor:
Base Text Sensor Configuration
------------------------------
.. code-block:: yaml
# Example sensor configuration
name: Livingroom Temperature
# Optional variables:
icon: "mdi:water-percent"
Configuration variables:
- **name** (**Required**, string): The name for the sensor.
- **icon** (*Optional*, icon): Manually set the icon to use for the sensor in the frontend.
- **internal** (*Optional*, boolean): Mark this component as internal. Internal components will
not be exposed to the frontend (like Home Assistant). Only specifying an ``id`` without
a ``name`` will implicitly set this to true.
- If MQTT enabled, All other options from :ref:`MQTT Component <config-mqtt-component>`.
Automations:
- **on_value** (*Optional*, :ref:`Automation <automation>`): An automation to perform
when a new value is published. See :ref:`text_sensor-on_value`.
Text Sensor Automation
----------------------
You can access the most recent state of the sensor in :ref:`lambdas <config-lambda>` using
``id(sensor_id).state``.
.. _text_sensor-on_value:
``on_value``
************
This automation will be triggered when a new value is published.
In :ref:`Lambdas <config-lambda>` you can get the value from the trigger with ``x``.
.. code-block:: yaml
text_sensor:
- platform: version
# ...
on_value:
then:
- lambda: |-
ESP_LOGD("main", "The current version is %s", x.c_str());
Configuration variables: See :ref:`Automation <automation>`.
.. _text_sensor-state_condition:
``text_sensor.state`` Condition
-------------------------------
This :ref:`Condition <config-condition>` allows you to check if a given text sensor
has a specific state.
.. code-block:: yaml
on_...:
- if:
condition:
# Checks if "my_text_sensor" has state "Hello World"
text_sensor.state:
id: my_text_sensor
state: 'Hello World'
Configuration variables:
- **id** (**Required**, :ref:`config-id`): The text sensor ID.
- **state** (**Required**, :ref:`templatable <config-templatable>`, string): The state to compare
to.
.. note::
This condition can also be expressed in :ref:`lambdas <config-lambda>`:
.. code-block:: cpp
if (id(my_text_sensor).state == "Hello World") {
// do something
}
.. _text_sensor-lambda_calls:
lambda calls
************
From :ref:`lambdas <config-lambda>`, you can call several methods on all text sensors to do some
advanced stuff (see the full API Reference for more info).
- ``publish_state()``: Manually cause the sensor to push out a value.
.. code-block:: cpp
// Within lambda, push a value of "Hello World"
id(my_sensor).publish_state("Hello World");
- ``.state``: Retrieve the current value of the sensor as an ``std::string`` object.
.. code-block:: cpp
// For example, create a custom log message when a value is received:
std::string val = id(my_sensor).state;
ESP_LOGI("main", "Value of my sensor: %s", val.c_str());
See Also
--------
- :apiref:`text_sensor/text_sensor.h`
- :ghedit:`Edit`
.. toctree::
:maxdepth: 1
:glob:
*