[python] pygments' markdown, revisited

v1.py

# -*- coding: utf-8 -*-
"""
    The Pygments Markdown Preprocessor
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    This fragment is a Markdown_ preprocessor that renders source code
    to HTML via Pygments.  To use it, invoke Markdown like so::

        from markdown import Markdown

        md = Markdown()
        CodeBlockProcessors().prepare(md)
        html = md.convert(someText)

    markdown is then a callable that can be passed to the context of
    a template and used in that template, for example.

    This uses CSS classes by default, so use
    ``pygmentize -S <some style> -f html > pygments.css``
    to create a stylesheet to be added to the website.

    You can then highlight source code in your markdown markup::

        [sourcecode:lexer]
        some code
        [/sourcecode]

    .. _Markdown: http://www.freewisdom.org/projects/python-markdown/

    :copyright: Copyright 2006-2012 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

# Options
# ~~~~~~~

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


import random
import re
import string

from markdown import TextPreprocessor, TextPostprocessor

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


class CodeBlockProcessors(object):
    PREFIX_SEED = 'TphNMKSiFB'
    PATTERN = re.compile(r'\s*\[sourcecode:(.+?)\](.+?)\[/sourcecode\]\s*', re.S)

    def __init__(self):
        self.pre = CodeBlockPreprocessor(self)
        self.post = CodeBlockPostprocessor(self)
        self.formatter = HtmlFormatter(noclasses=INLINESTYLES)
        self.stash = []

    def prepare(self, md):
        md.textPreprocessors.insert(0, self.pre)
        md.textPostprocessors.append(self.post)

    def choose_prefix(self, lines):
        p = self.PREFIX_SEED
        while lines.find(p) != -1:
            p += random.choice(string.letters)
        self.code_prefix = p

    def stash_code_blocks(self, lines):
        self.choose_prefix(lines)

        def repl(m):
            index = len(self.stash)
            self.stash.append(m)
            return '\n\n<div class="%s">%s%d</div>\n\n' % (
                self.formatter.cssclass,
                self.code_prefix,
                index)

        return self.PATTERN.sub(repl, lines)

    def unstash_code_blocks(self, lines):
        def repl(m):
            index = int(m.group(1))
            m = self.stash[index]
            try:
                lexer = get_lexer_by_name(m.group(1))
            except ValueError:
                lexer = TextLexer()
            return highlight(m.group(2), lexer, self.formatter)

        return re.sub(r'<div class="%s">%s(\d)</div>' % (self.formatter.cssclass, self.code_prefix),
            repl, lines)



class CodeBlockPreprocessor(TextPreprocessor):
    def __init__(self, processors):
        self.processors = processors

    def run(self, lines):
        return self.processors.stash_code_blocks(lines)


class CodeBlockPostprocessor(TextPostprocessor):
    def __init__(self, processors):
        self.processors = processors

    def run(self, lines):
        return self.processors.unstash_code_blocks(lines)

v2.py

# -*- coding: utf-8 -*-
"""
    The Pygments Markdown Preprocessor
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    This fragment is a Markdown_ preprocessor that renders source code
    to HTML via Pygments.  To use it, invoke Markdown like so::

        from markdown import Markdown

        md = Markdown()
        md.textPreprocessors.insert(0, CodeBlockPreprocessor())
        html = md.convert(someText)

    markdown is then a callable that can be passed to the context of
    a template and used in that template, for example.

    This uses CSS classes by default, so use
    ``pygmentize -S <some style> -f html > pygments.css``
    to create a stylesheet to be added to the website.

    You can then highlight source code in your markdown markup::

        [sourcecode:lexer]
        some code
        [/sourcecode]

    .. _Markdown: http://www.freewisdom.org/projects/python-markdown/

    :copyright: Copyright 2006-2012 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

# Options
# ~~~~~~~

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


import re

from markdown import TextPreprocessor

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


class CodeBlockPreprocessor(TextPreprocessor):

    pattern = re.compile(
        r'\s*\[sourcecode:(.+?)\](.+?)\[/sourcecode\]\s*', re.S)

    formatter = HtmlFormatter(noclasses=INLINESTYLES)

    def __init__(self, md):
        self.md = md

    def run(self, lines):
        def repl(m):
            try:
                lexer = get_lexer_by_name(m.group(1))
            except ValueError:
                lexer = TextLexer()
            code = highlight(m.group(2), lexer, self.formatter)
            place_holder = self.md.htmlStash.store(code.strip())
            return "\n\n%s\n\n" % place_holder
        return self.pattern.sub(
            repl, lines)