Source

todd-django-articles / articles / directives.py

"""
The Pygments reStructuredText directive
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This fragment is a Docutils_ 0.4 directive that renders source code
(to HTML only, currently) via Pygments.

To use it, adjust the options below and copy the code into a module
that you import on initialization.  The code then automatically
registers a ``sourcecode`` directive that you can use instead of
normal code blocks like this::

    .. sourcecode:: python

        My code goes here.

If you want to have different code styles, e.g. one with line numbers
and one without, add formatters with their names in the VARIANTS dict
below.  You can invoke them instead of the DEFAULT one by using a
directive option::

    .. sourcecode:: python
        :linenos:

        My code goes here.

Look at the `directive documentation`_ to get all the gory details.

.. _Docutils: http://docutils.sf.net/
.. _directive documentation:
    http://docutils.sourceforge.net/docs/howto/rst-directives.html

:copyright: 2007 by Georg Brandl.
:license: BSD, see LICENSE for more details.
"""

# Options
# ~~~~~~~

# Set to True if you want inline CSS styles instead of classes
INLINESTYLES = False

try:
    from pygments.formatters import HtmlFormatter

    # The default formatter
    DEFAULT = HtmlFormatter(noclasses=INLINESTYLES)

    # Add name -> formatter pairs for every variant you want to use
    VARIANTS = {
        'linenos': HtmlFormatter(noclasses=INLINESTYLES, linenos=True),
    }

    from docutils import nodes
    from docutils.parsers.rst import directives

    from pygments import highlight
    from pygments.lexers import get_lexer_by_name, TextLexer

    def pygments_directive(name, arguments, options, content, lineno,
                        content_offset, block_text, state, state_machine):
        try:
            lexer = get_lexer_by_name(arguments[0])
        except ValueError:
            # no lexer found - use the text one instead of an exception
            lexer = TextLexer()
        # take an arbitrary option if more than one is given
        formatter = options and VARIANTS[options.keys()[0]] or DEFAULT
        parsed = highlight(u'\n'.join(content), lexer, formatter)
        parsed = '<div class="codeblock">%s</div>' % parsed
        return [nodes.raw('', parsed, format='html')]

    pygments_directive.arguments = (1, 0, 1)
    pygments_directive.content = 1
    pygments_directive.options = dict([(key, directives.flag) for key in VARIANTS])

    directives.register_directive('sourcecode', pygments_directive)

    # create an alias, so we can use it with rst2pdf... leave the other for
    # backwards compatibility
    directives.register_directive('code-block', pygments_directive)
except:
    # the user probably doesn't have pygments installed
    pass