Test if callable: callable

The callable test checks whether a value is callable, meaning it can be invoked as a function. It returns true for functions, methods, and other callable objects, and false for regular values like strings, numbers, and lists.

In typical Home Assistant template usage, you rarely need to check if something is callable. However, this test can be useful in templates where you work with template macros or need to verify that a value is a function before attempting to call it.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{% if range is callable %}
  range is callable
{% endif %}

range is callable

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

callable(
    value: Any,
) -> bool

Function parameters

The following parameters can be provided to this test.

Good to know

• Most template values are not callable. This test is primarily useful when working with macros wrapped via as_function.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Check various values

Functions are callable, but regular values are not.

{{ range is callable }}
{{ "hello" is callable }}
{{ 42 is callable }}

true
false
false

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Test if defined: defined - Tests whether a variable is defined (not undefined).

• Get the type of a value: typeof - Returns the type name of a value as a string.