Developing extensions for Sphinx¶
Since many projects will need special features in their documentation, Sphinx is designed to be extensible on several levels.
This is what you can do in an extension: First, you can add new builders to support new output formats or actions on the parsed documents. Then, it is possible to register custom reStructuredText roles and directives, extending the markup. And finally, there are so-called “hook points” at strategic places throughout the build process, where an extension can register a hook and run specialized code.
An extension is simply a Python module. When an extension is loaded, Sphinx
imports this module and executes its setup()
function, which in turn
notifies Sphinx of everything the extension offers – see the extension tutorial
for examples.
The configuration file itself can be treated as an extension if it contains a
setup()
function. All other extensions to load must be listed in the
extensions
configuration value.
Discovery of builders by entry point¶
New in version 1.6.
Builder extensions can be discovered by means of entry points so
that they do not have to be listed in the extensions
configuration
value.
Builder extensions should define an entry point in the sphinx.builders
group. The name of the entry point needs to match your builder’s
name
attribute, which is the name passed to the
sphinx-build -b
option. The entry point value should equal the
dotted name of the extension module. Here is an example of how an entry point
for ‘mybuilder’ can be defined in the extension’s setup.py
:
setup(
# ...
entry_points={
'sphinx.builders': [
'mybuilder = my.extension.module',
],
}
)
Note that it is still necessary to register the builder using
add_builder()
in the extension’s setup()
function.
Extension metadata¶
New in version 1.3.
The setup()
function can return a dictionary. This is treated by Sphinx
as metadata of the extension. Metadata keys currently recognized are:
'version'
: a string that identifies the extension version. It is used for extension version requirement checking (seeneeds_extensions
) and informational purposes. If not given,"unknown version"
is substituted.'parallel_read_safe'
: a boolean that specifies if parallel reading of source files can be used when the extension is loaded. It defaults toFalse
, i.e. you have to explicitly specify your extension to be parallel-read-safe after checking that it is.'parallel_write_safe'
: a boolean that specifies if parallel writing of output files can be used when the extension is loaded. Since extensions usually don’t negatively influence the process, this defaults toTrue
.