rhodecode/lib/markup_renderer.py

# -*- coding: utf-8 -*-
"""
    rhodecode.lib.markup_renderer
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    
    Renderer for markup languages with ability to parse using rst or markdown
    
    :created_on: Oct 27, 2011
    :author: marcink
    :copyright: (C) 2009-2011 Marcin Kuzminski <[e-mail]>
    :license: GPLv3, see COPYING for more details.
"""
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import re
import logging

from rhodecode.lib import safe_unicode

log = logging.getLogger(__name__)

class MarkupRenderer(object):
    RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES = ['include', 'meta', 'raw']
    
    MARKDOWN_PAT = re.compile(r'md|mkdn?|mdown|markdown',re.IGNORECASE)
    RST_PAT = re.compile(r're?st',re.IGNORECASE)
    PLAIN_PAT = re.compile(r'readme',re.IGNORECASE)
    
    def __detect_renderer(self, source, filename=None):
        """
        runs detection of what renderer should be used for generating html
        from a markup language
        
        filename can be also explicitly a renderer name
        
        :param source:
        :param filename:
        """

        if MarkupRenderer.MARKDOWN_PAT.findall(filename):
            detected_renderer = 'markdown'
        elif MarkupRenderer.RST_PAT.findall(filename):
            detected_renderer = 'rst'
        elif MarkupRenderer.PLAIN_PAT.findall(filename):
            detected_renderer = 'rst'
        else:
            detected_renderer = 'plain'

        return getattr(MarkupRenderer, detected_renderer)


    def render(self, source, filename=None):
        """
        Renders a given filename using detected renderer
        it detects renderers based on file extension or mimetype.
        At last it will just do a simple html replacing new lines with <br/>
        
        :param file_name:
        :param source:
        """

        renderer = self.__detect_renderer(source, filename)
        readme_data = renderer(source)
        return readme_data

    @classmethod
    def plain(cls, source):
        source = safe_unicode(source)
        def urlify_text(text):
            url_pat = re.compile(r'(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]'
                                 '|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)')

            def url_func(match_obj):
                url_full = match_obj.groups()[0]
                return '<a href="%(url)s">%(url)s</a>' % ({'url':url_full})

            return url_pat.sub(url_func, text)

        source = urlify_text(source)
        return '<br />' + source.replace("\n", '<br />')


    @classmethod
    def markdown(cls, source):
        source = safe_unicode(source)
        try:
            import markdown as __markdown
            return __markdown.markdown(source)
        except ImportError:
            log.warning('Install markdown to use this function')
            return cls.plain(source)


    @classmethod
    def rst(cls, source):
        source = safe_unicode(source)
        try:
            from docutils.core import publish_parts
            from docutils.parsers.rst import directives
            docutils_settings = dict([(alias, None) for alias in
                                cls.RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES])

            docutils_settings.update({'input_encoding': 'unicode',
                                      'report_level':4})

            for k, v in docutils_settings.iteritems():
                directives.register_directive(k, v)

            parts = publish_parts(source=source,
                                  writer_name="html4css1",
                                  settings_overrides=docutils_settings)

            return parts['html_title'] + parts["fragment"]
        except ImportError:
            log.warning('Install docutils to use this function')
            return cls.plain(source)