#!/usr/bin/python """ CodeHilite Extension for Python-Markdown ======================================= Adds code/syntax highlighting to standard Python-Markdown code blocks. By [Waylan Limberg](http://achinghead.com/). Project website: http://achinghead.com/markdown-wikilinks/ Contact: waylan [at] gmail [dot] com License: [BSD](http://www.opensource.org/licenses/bsd-license.php) Version: 0.2 (April 30, 2008) Dependencies: * [Python 2.3+](http://python.org/) * [Markdown 1.7+](http://www.freewisdom.org/projects/python-markdown/) * [Pygments](http://pygments.org/) """ import markdown # --------------- CONSTANTS YOU MIGHT WANT TO MODIFY ----------------- try: TAB_LENGTH = markdown.TAB_LENGTH except AttributeError: TAB_LENGTH = 4 # ------------------ The Main CodeHilite Class ---------------------- class CodeHilite: """ Determine language of source code, and pass it into the pygments hilighter. Basic Usage: >>> code = CodeHilite(src = text) >>> html = code.hilite() * src: Source string or any object with a .readline attribute. * linenos: (Boolen) Turn line numbering 'on' or 'off' (off by default). * css_class: Set class name of wrapper div ('codehilite' by default). Low Level Usage: >>> code = CodeHilite() >>> code.src = text # String or anything with a .readline attribute >>> code.linenos = True # True or False; Turns line numbering on or of. >>> html = code.hilite() """ def __init__(self, src=None, linenos=False, css_class="codehilite"): self.src = src self.lang = None self.linenos = linenos self.css_class = css_class def hilite(self): """ Pass code to the [Pygments](http://pygments.pocoo.org/) highliter with optional line numbers. The output should then be styled with css to your liking. No styles are applied by default - only styling hooks (i.e.: ). returns : A string of html. """ self.src = self.src.strip('\n') self._getLang() try: from pygments import highlight from pygments.lexers import get_lexer_by_name, guess_lexer, \ TextLexer from pygments.formatters import HtmlFormatter except ImportError: # just escape and pass through txt = self._escape(self.src) if self.linenos: txt = self._number(txt) else : txt = '
%s
\n'% \ (self.css_class, txt) return txt else: try: lexer = get_lexer_by_name(self.lang) except ValueError: try: lexer = guess_lexer(self.src) except ValueError: lexer = TextLexer() formatter = HtmlFormatter(linenos=self.linenos, cssclass=self.css_class) return highlight(self.src, lexer, formatter) def _escape(self, txt): """ basic html escaping """ txt = txt.replace('&', '&') txt = txt.replace('<', '<') txt = txt.replace('>', '>') txt = txt.replace('"', '"') return txt def _number(self, txt): """ Use
    for line numbering """ # Fix Whitespace txt = txt.replace('\t', ' '*TAB_LENGTH) txt = txt.replace(" "*4, "    ") txt = txt.replace(" "*3, "   ") txt = txt.replace(" "*2, "  ") # Add line numbers lines = txt.splitlines() txt = '
      \n'
        for line in lines:
            txt += '\t
    1. %s
      2. \n'% line
        txt += '
    \n' return txt def _getLang(self): """ Determines language of a code block from shebang lines and whether said line should be removed or left in place. If the sheband line contains a path (even a single /) then it is assumed to be a real shebang lines and left alone. However, if no path is given (e.i.: #!python or :::python) then it is assumed to be a mock shebang for language identifitation of a code fragment and removed from the code block prior to processing for code highlighting. When a mock shebang (e.i: #!python) is found, line numbering is turned on. When colons are found in place of a shebang (e.i.: :::python), line numbering is left in the current state - off by default. """ import re #split text into lines lines = self.src.split("\n") #pull first line to examine fl = lines.pop(0) c = re.compile(r''' (?:(?:::+)|(?P[#]!)) # Shebang or 2 or more colons. (?P(?:/\w+)*[/ ])? # Zero or 1 path (?P[\w+-]*) # The language ''', re.VERBOSE) # search first line for shebang m = c.search(fl) if m: # we have a match try: self.lang = m.group('lang').lower() except IndexError: self.lang = None if m.group('path'): # path exists - restore first line lines.insert(0, fl) if m.group('shebang'): # shebang exists - use line numbers self.linenos = True else: # No match lines.insert(0, fl) self.src = "\n".join(lines).strip("\n") # ------------------ The Markdown Extension ------------------------------- class HilitePostprocessor(markdown.Postprocessor): """ Hilight source code in code blocks. """ def run(self, root): """ Find code blocks and store in htmlStash. """ blocks = root.getiterator('pre') for block in blocks: children = block.getchildren() if len(children) == 1 and children[0].tag == 'code': code = CodeHilite(children[0].text, linenos=self.config['force_linenos'][0], css_class=self.config['css_class'][0]) placeholder = self.markdown.htmlStash.store(code.hilite(), safe=True) # Clear codeblock in etree instance block.clear() # Change to p element which will later # be removed when inserting raw html block.tag = 'p' block.text = placeholder class CodeHiliteExtension(markdown.Extension): """ Add source code hilighting to markdown codeblocks. """ def __init__(self, configs): # define default configs self.config = { 'force_linenos' : [False, "Force line numbers - Default: False"], 'css_class' : ["codehilite", "Set class name for wrapper
    - Default: codehilite"], } # Override defaults with user settings for key, value in configs: self.setConfig(key, value) def extendMarkdown(self, md, md_globals): """ Add HilitePostprocessor to Markdown instance. """ hiliter = HilitePostprocessor(md) hiliter.config = self.config md.postprocessors.add("hilite", hiliter, "_begin") def makeExtension(configs={}): return CodeHiliteExtension(configs=configs)