sphinx/doc/extdev/markupapi.rst
2016-02-13 16:00:46 +01:00

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ReStructuredText

Docutils markup API
===================
This section describes the API for adding ReST markup elements (roles and
directives).
Roles
-----
Directives
----------
Directives are handled by classes derived from
``docutils.parsers.rst.Directive``. They have to be registered by an extension
using :meth:`.Sphinx.add_directive` or :meth:`.Sphinx.add_directive_to_domain`.
.. module:: docutils.parsers.rst
.. class:: Directive
The markup syntax of the new directive is determined by the follow five class
attributes:
.. autoattribute:: required_arguments
.. autoattribute:: optional_arguments
.. autoattribute:: final_argument_whitespace
.. autoattribute:: option_spec
Option validator functions take a single parameter, the option argument
(or ``None`` if not given), and should validate it or convert it to the
proper form. They raise :exc:`ValueError` or :exc:`TypeError` to indicate
failure.
There are several predefined and possibly useful validators in the
:mod:`docutils.parsers.rst.directives` module.
.. autoattribute:: has_content
New directives must implement the :meth:`run` method:
.. method:: run()
This method must process the directive arguments, options and content, and
return a list of Docutils/Sphinx nodes that will be inserted into the
document tree at the point where the directive was encountered.
Instance attributes that are always set on the directive are:
.. attribute:: name
The directive name (useful when registering the same directive class under
multiple names).
.. attribute:: arguments
The arguments given to the directive, as a list.
.. attribute:: options
The options given to the directive, as a dictionary mapping option names
to validated/converted values.
.. attribute:: content
The directive content, if given, as a :class:`.ViewList`.
.. attribute:: lineno
The absolute line number on which the directive appeared. This is not
always a useful value; use :attr:`srcline` instead.
.. attribute:: src
The source file of the directive.
.. attribute:: srcline
The line number in the source file on which the directive appeared.
.. attribute:: content_offset
Internal offset of the directive content. Used when calling
``nested_parse`` (see below).
.. attribute:: block_text
The string containing the entire directive.
.. attribute:: state
state_machine
The state and state machine which controls the parsing. Used for
``nested_parse``.
ViewLists
^^^^^^^^^
Docutils represents document source lines in a class
``docutils.statemachine.ViewList``. This is a list with extended functionality
-- for one, slicing creates views of the original list, and also the list
contains information about the source line numbers.
The :attr:`Directive.content` attribute is a ViewList. If you generate content
to be parsed as ReST, you have to create a ViewList yourself. Important for
content generation are the following points:
* The constructor takes a list of strings (lines) and a source (document) name.
* The ``.append()`` method takes a line and a source name as well.
Parsing directive content as ReST
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Many directives will contain more markup that must be parsed. To do this, use
one of the following APIs from the :meth:`Directive.run` method:
* ``self.state.nested_parse``
* :func:`sphinx.util.nodes.nested_parse_with_titles` -- this allows titles in
the parsed content.
Both APIs parse the content into a given node. They are used like this::
node = docutils.nodes.paragraph()
# either
nested_parse_with_titles(self.state, self.result, node)
# or
self.state.nested_parse(self.result, 0, node)
If you don't need the wrapping node, you can use any concrete node type and
return ``node.children`` from the Directive.
.. seealso::
`Creating directives <http://docutils.sourceforge.net/docs/howto/rst-directives.html>`_
HOWTO of the Docutils documentation