.. include:: ../links.inc

.. _extending_extension:

Creating a ``junifer`` extension
================================

``junifer`` is designed to be easily extensible. Through the use of a registry
and decorators, you can easily add new functionality to ``junifer`` during
runtime. This is done by creating a new Python module and importing it before
running ``junifer``.

A special consideration has to be made when using the
:ref:`code-less configuration<codeless>`. In this case, the
``with`` statement can be used to import a module or run a Python file.

In the following example, we instruct ``junifer`` to first import ``my_module``
and then run the ``my_file.py`` file:

.. code-block:: yaml

    with:
      - my_module
      - my_file.py

Thus, the code from ``my_file.py`` will be executed before running ``junifer``.
This is the ideal place to include ``junifer`` extensions.

.. important::

   Some ``junifer`` commands will not consider files imported from files included
   in the ``with`` statement. If ``my_file.py`` imports ``my_other_file.py``,
   some of the ``junifer`` commands will not consider ``my_other_file.py``. Either
   place all the code in one file or add multiple files to the ``with``
   statement.