""" CodeHilite Extension for Python-Markdown ======================================== Adds code/syntax highlighting to standard Python-Markdown code blocks. Copyright 2006-2008 [Waylan Limberg](http://achinghead.com/). Project website: Contact: markdown@freewisdom.org License: BSD (see ../LICENSE.md for details) Dependencies: * [Python 2.3+](http://python.org/) * [Markdown 2.0+](http://packages.python.org/Markdown/) * [Pygments](http://pygments.org/) """ from six import text_type from typing import Any, Dict, List, Optional, Tuple, Union from xml.etree.ElementTree import ElementTree from zerver.lib.str_utils import force_text import markdown try: from pygments import highlight from pygments.lexers import get_lexer_by_name, guess_lexer, TextLexer from pygments.formatters import HtmlFormatter pygments = True except ImportError: pygments = False # ------------------ The Main CodeHilite Class ---------------------- class CodeHilite(object): """ Determine language of source code, and pass it into the pygments hilighter. Basic Usage: >>> code = CodeHilite(src = 'some text') >>> html = code.hilite() * src: Source string or any object with a .readline attribute. * force_linenos: (Boolean) Force line numbering 'on' (True) or 'off' (False). If not specified, number lines iff a shebang line is present. * guess_lang: (Boolean) Turn language auto-detection 'on' or 'off' (on by default). * css_class: Set class name of wrapper div ('codehilite' by default). Low Level Usage: >>> code = CodeHilite() >>> code.src = 'some text' # String or anything with a .readline attr. >>> code.linenos = True # True or False; Turns line numbering on or of. >>> html = code.hilite() """ def __init__(self, src=None, force_linenos=None, guess_lang=True, css_class="codehilite", lang=None, style='default', noclasses=False, tab_length=4): # type: (Optional[text_type], Optional[bool], bool, text_type, Optional[text_type], text_type, bool, int) -> None self.src = src self.lang = lang self.linenos = force_linenos self.guess_lang = guess_lang self.css_class = css_class self.style = style self.noclasses = noclasses self.tab_length = tab_length def hilite(self): # type: () -> text_type """ 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._getLang() if pygments: try: lexer = get_lexer_by_name(self.lang) except ValueError: try: if self.guess_lang: lexer = guess_lexer(self.src) else: lexer = TextLexer() except ValueError: lexer = TextLexer() formatter = HtmlFormatter(linenos=bool(self.linenos), cssclass=self.css_class, style=self.style, noclasses=self.noclasses) 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.linenos: classes.append('linenums') class_str = '' if classes: class_str = ' class="%s"' % ' '.join(classes) return '
%s
\n'% \ (self.css_class, class_str, txt) def _getLang(self): # type: () -> None """ 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. """ import re # split text into lines lines = self.src.split("\n") # pull first line to examine fl = lines.pop(0) c = re.compile(u''' (?:(?:^::+)|(?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') and self.linenos is None: # 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 HiliteTreeprocessor(markdown.treeprocessors.Treeprocessor): """ Hilight source code in code blocks. """ def run(self, root): # type: (ElementTree) -> None """ Find code blocks and store in htmlStash. """ blocks = root.getiterator('pre') for block in blocks: children = block.getchildren() tag = force_text(children[0].tag) if len(children) == 1 and tag == 'code': text = force_text(children[0].text) code = CodeHilite(text, force_linenos=self.config['force_linenos'], guess_lang=self.config['guess_lang'], css_class=self.config['css_class'], style=self.config['pygments_style'], noclasses=self.config['noclasses'], tab_length=self.markdown.tab_length) 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): # type: (List[Tuple[str, Union[bool, None, text_type]]]) -> None # define default configs self.config = { 'force_linenos' : [None, "Force line numbers - Default: detect based on shebang"], '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'] } # type: Dict[str, List[Any]] # Override defaults with user settings for key, value in configs: # convert strings to booleans if value == 'True': value = True if value == 'False': value = False self.setConfig(key, value) def extendMarkdown(self, md, md_globals): # type: (markdown.Markdown, Dict[str, Any]) -> None """ Add HilitePostprocessor to Markdown instance. """ hiliter = HiliteTreeprocessor(md) hiliter.config = self.getConfigs() md.treeprocessors.add("hilite", hiliter, " CodeHiliteExtension return CodeHiliteExtension(configs=configs or [])