.. _howto/admin/extensions:

====================================
Enabling Jupyter Notebook extensions
====================================

Jupyter contributed notebook 
`extensions <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/index.html>`_ are
community-contributed and maintained plug-ins to the Jupyter notebook. These extensions
serve many purposes, from `pedagogical tools <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions/codefolding/readme.html>`_
to tools for `converting <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions/latex_envs/README.html>`_
and `editing <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions/spellchecker/README.html>`_
notebooks.

Extensions are often added and enabled through the graphical user interface of the notebook.
However, this interface only makes the extension available to the user, not all users on a 
hub. Instead, to make contributed extensions available to your users, you will use the command 
line. This can be completed using the terminal in the JupyterHub (or via SSH-ing into your 
VM and using this terminal).

.. _tljh_extension_cli:

Enabling extensions via the command line 
========================================

#. There are `multiple ways <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/install.html>`_
   to install contributed extensions. For this example, we will use ``pip``.

   .. code-block:: bash

      sudo -E pip install jupyter_contrib_nbextensions

#. Next, add the notebook extension style files to the Jupyter configuration files.

   .. code-block:: bash

      sudo -E jupyter contrib nbextension install --system

#. Then, you will enable the extensions you would like to use. The syntax for this is 
   ``jupyter nbextension enable`` followed by the path to the desired extension's main file. 
   For example, to enable `scratchpad <https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions/scratchpad/README.html>`_,
   you would type the following: 

   .. code-block:: bash

      sudo -E jupyter nbextension enable scratchpad/main --system

#. When this is completed, the enabled extension should be visible in the extension list:

   .. code-block:: bash

      jupyter nbextension list

#. You can also verify the availability of the extension via its user interface in the notebook.
   For example, spellchecker adds an ABC checkmark icon to the interface.

   .. image:: ../../images/admin/enable-spellcheck.png
      :alt: spellcheck-interface-changes


