""" CodeHilite Extension for Python-Markdown ======================================== Adds code/syntax highlighting to standard Python-Markdown code blocks. See for documentation. Original code Copyright 2006-2008 [Waylan Limberg](http://achinghead.com/). All changes Copyright 2008-2014 The Python Markdown Project License: [BSD](http://www.opensource.org/licenses/bsd-license.php) """ from __future__ import absolute_import from __future__ import unicode_literals from . import Extension from ..treeprocessors import Treeprocessor try: from pygments import highlight from pygments.lexers import get_lexer_by_name, guess_lexer from pygments.formatters import get_formatter_by_name pygments = True except ImportError: pygments = False def parse_hl_lines(expr): """Support our syntax for emphasizing certain lines of code. expr should be like '1 2' to emphasize lines 1 and 2 of a code block. Returns a list of ints, the line numbers to emphasize. """ if not expr: return [] try: return list(map(int, expr.split())) except ValueError: return [] # ------------------ The Main CodeHilite Class ---------------------- class CodeHilite(object): """ Determine language of source code, and pass it into pygments hilighter. Basic Usage: >>> code = CodeHilite(src = 'some text') >>> html = code.hilite() * src: Source string or any object with a .readline attribute. * linenums: (Boolean) Set line numbering to 'on' (True), 'off' (False) or 'auto'(None). Set to 'auto' by default. * guess_lang: (Boolean) Turn language auto-detection 'on' or 'off' (on by default). * css_class: Set class name of wrapper div ('codehilite' by default). * hl_lines: (List of integers) Lines to emphasize, 1-indexed. Low Level Usage: >>> code = CodeHilite() >>> code.src = 'some text' # String or anything with a .readline attr. >>> code.linenos = True # Turns line numbering on or of. >>> html = code.hilite() """ def __init__(self, src=None, linenums=None, guess_lang=True, css_class="codehilite", lang=None, style='default', noclasses=False, tab_length=4, hl_lines=None, use_pygments=True): self.src = src self.lang = lang self.linenums = linenums self.guess_lang = guess_lang self.css_class = css_class self.style = style self.noclasses = noclasses self.tab_length = tab_length self.hl_lines = hl_lines or [] self.use_pygments = use_pygments 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') if self.lang is None: self._parseHeader() if pygments and self.use_pygments: try: lexer = get_lexer_by_name(self.lang) except ValueError: try: if self.guess_lang: lexer = guess_lexer(self.src) else: lexer = get_lexer_by_name('text') except ValueError: lexer = get_lexer_by_name('text') formatter = get_formatter_by_name('html', linenos=self.linenums, cssclass=self.css_class, style=self.style, noclasses=self.noclasses, hl_lines=self.hl_lines) return highlight(self.src, lexer, formatter) else: # just escape and build markup usable by JS highlighting libs txt = self.src.replace('&', '&') txt = txt.replace('<', '<') txt = txt.replace('>', '>') txt = txt.replace('"', '"') classes = [] if self.lang: classes.append('language-%s' % self.lang) if self.linenums: classes.append('linenums') class_str = '' if classes: class_str = ' class="%s"' % ' '.join(classes) return '
%s
\n' % \ (self.css_class, class_str, txt) def _parseHeader(self): """ Determines language of a code block from shebang line 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 line 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. Also parses optional list of highlight lines, like: :::python hl_lines="1 3" """ 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 \s* # Arbitrary whitespace # Optional highlight lines, single- or double-quote-delimited (hl_lines=(?P"|')(?P.*?)(?P=quot))? ''', 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 self.linenums is None and m.group('shebang'): # Overridable and Shebang exists - use line numbers self.linenums = True self.hl_lines = parse_hl_lines(m.group('hl_lines')) else: # No match lines.insert(0, fl) self.src = "\n".join(lines).strip("\n") # ------------------ The Markdown Extension ------------------------------- class HiliteTreeprocessor(Treeprocessor): """ Hilight source code in code blocks. """ def run(self, root): """ Find code blocks and store in htmlStash. """ blocks = root.iter('pre') for block in blocks: if len(block) == 1 and block[0].tag == 'code': code = CodeHilite( block[0].text, linenums=self.config['linenums'], guess_lang=self.config['guess_lang'], css_class=self.config['css_class'], style=self.config['pygments_style'], noclasses=self.config['noclasses'], tab_length=self.md.tab_length, use_pygments=self.config['use_pygments'] ) placeholder = self.md.htmlStash.store(code.hilite()) # 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(Extension): """ Add source code hilighting to markdown codeblocks. """ def __init__(self, **kwargs): # define default configs self.config = { 'linenums': [None, "Use lines numbers. True=yes, False=no, None=auto"], 'guess_lang': [True, "Automatic language detection - Default: True"], 'css_class': ["codehilite", "Set class name for wrapper
- " "Default: codehilite"], 'pygments_style': ['default', 'Pygments HTML Formatter Style ' '(Colorscheme) - Default: default'], 'noclasses': [False, 'Use inline styles instead of CSS classes - ' 'Default false'], 'use_pygments': [True, 'Use Pygments to Highlight code blocks. ' 'Disable if using a JavaScript library. ' 'Default: True'] } super(CodeHiliteExtension, self).__init__(**kwargs) def extendMarkdown(self, md): """ Add HilitePostprocessor to Markdown instance. """ hiliter = HiliteTreeprocessor(md) hiliter.config = self.getConfigs() md.treeprocessors.register(hiliter, 'hilite', 30) md.registerExtension(self) def makeExtension(**kwargs): # pragma: no cover return CodeHiliteExtension(**kwargs)