`.
.. _theming-static-templates:
Static templates
~~~~~~~~~~~~~~~~
Since theme options are meant for the user to configure a theme more easily,
without having to write a custom stylesheet, it is necessary to be able to
template static files as well as HTML files. Therefore, Sphinx supports
so-called "static templates", like this:
If the name of a file in the ``static/`` directory of a theme (or in the user's
static path) ends with ``.jinja`` or ``_t``, it will be processed by the
template engine. The suffix will be removed from the final file name.
For example, a theme with a ``static/theme_styles.css.jinja`` file could use
templating to put options into the stylesheet.
When a documentation project is built with that theme,
the output directory will contain a ``_static/theme_styles.css`` file
where all template tags have been processed.
.. versionchanged:: 7.4
The preferred suffix for static templates is now ``.jinja``, in line with
the Jinja project's `recommended file extension`_.
The ``_t`` file suffix for static templates is now considered 'legacy', and
support may eventually be removed.
If a static template with either a ``_t`` suffix or a ``.jinja`` suffix is
detected, it will be processed by the template engine, with the suffix
removed from the final file name.
.. _recommended file extension: https://jinja.palletsprojects.com/en/latest/templates/#template-file-extension
Use custom page metadata in HTML templates
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Any key / value pairs in :doc:`field lists `
that are placed *before* the page's title will be available to the Jinja
template when building the page within the :data:`meta` attribute. For example,
if a page had the following text before its first title:
.. code-block:: rst
:mykey: My value
My first title
--------------
Then it could be accessed within a Jinja template like so:
.. code-block:: jinja
{%- if meta is mapping %}
{{ meta.get("mykey") }}
{%- endif %}
Note the check that ``meta`` is a dictionary ("mapping" in Jinja
terminology) to ensure that using it in this way is valid.
Defining custom template functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sometimes it is useful to define your own function in Python that you wish to
then use in a template. For example, if you'd like to insert a template value
with logic that depends on the user's configuration in the project, or if you'd
like to include non-trivial checks and provide friendly error messages for
incorrect configuration in the template.
To define your own template function, you'll need to define two functions
inside your module:
* A **page context event handler** (or **registration**) function. This is
connected to the :class:`.Sphinx` application via an event callback.
* A **template function** that you will use in your Jinja template.
First, define the registration function, which accepts the arguments for
:event:`html-page-context`.
Within the registration function, define the template function that you'd like to
use within Jinja. The template function should return a string or Python objects
(lists, dictionaries) with strings inside that Jinja uses in the templating process
.. note::
The template function will have access to all of the variables that
are passed to the registration function.
At the end of the registration function, add the template function to the
Sphinx application's context with ``context['template_func'] = template_func``.
Finally, in your extension's ``setup()`` function, add your registration
function as a callback for :event:`html-page-context`.
.. code-block:: python
# The registration function
def setup_my_func(app, pagename, templatename, context, doctree):
# The template function
def my_func(mystring):
return "Your string is %s" % mystring
# Add it to the page's context
context['my_func'] = my_func
# Your extension's setup function
def setup(app):
app.connect("html-page-context", setup_my_func)
Now, you will have access to this function in jinja like so:
.. code-block:: jinja
{{ my_func("some string") }}
Add your own static files to the build assets
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
By default, Sphinx copies static files on the ``static/`` directory of the template
directory. However, if your package needs to place static files outside of the
``static/`` directory for some reasons, you need to copy them to the ``_static/``
directory of HTML outputs manually at the build via an event hook. Here is an
example of code to accomplish this:
.. code-block:: python
from os import path
from sphinx.util.fileutil import copy_asset_file
def copy_custom_files(app, exc):
if app.builder.format == 'html' and not exc:
staticdir = path.join(app.builder.outdir, '_static')
copy_asset_file('path/to/myextension/_static/myjsfile.js', staticdir)
def setup(app):
app.connect('build-finished', copy_custom_files)
Inject JavaScript based on user configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If your extension makes use of JavaScript, it can be useful to allow users
to control its behavior using their Sphinx configuration. However, this can
be difficult to do if your JavaScript comes in the form of a static library
(which will not be built with Jinja).
There are two ways to inject variables into the JavaScript space based on user
configuration.
First, you may append ``_t`` to the end of any static files included with your
extension. This will cause Sphinx to process these files with the templating
engine, allowing you to embed variables and control behavior.
For example, the following JavaScript structure:
.. code-block:: none
mymodule/
├── _static
│ └── myjsfile.js_t
└── mymodule.py
Will result in the following static file placed in your HTML's build output:
.. code-block:: none
_build/
└── html
└── _static
└── myjsfile.js
See :ref:`theming-static-templates` for more information.
Second, you may use the :meth:`.Sphinx.add_js_file` method without pointing it
to a file. Normally, this method is used to insert a new JavaScript file
into your site. However, if you do *not* pass a file path, but instead pass
a string to the "body" argument, then this text will be inserted as JavaScript
into your site's head. This allows you to insert variables into your project's
JavaScript from Python.
For example, the following code will read in a user-configured value and then
insert this value as a JavaScript variable, which your extension's JavaScript
code may use:
.. code-block:: python
# This function reads in a variable and inserts it into JavaScript
def add_js_variable(app):
# This is a configuration that you've specified for users in `conf.py`
js_variable = app.config['my_javascript_variable']
js_text = "var my_variable = '%s';" % js_variable
app.add_js_file(None, body=js_text)
# We connect this function to the step after the builder is initialized
def setup(app):
# Tell Sphinx about this configuration variable
app.add_config_value('my_javascript_variable', 0, 'html')
# Run the function after the builder is initialized
app.connect('builder-inited', add_js_variable)
As a result, in your theme you can use code that depends on the presence of
this variable. Users can control the variable's value by defining it in their
:file:`conf.py` file.
.. [1] It is not an executable Python file, as opposed to :file:`conf.py`,
because that would pose an unnecessary security risk if themes are
shared.