""" 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](https://opensource.org/licenses/bsd-license.php) """ from . import Extension from ..treeprocessors import Treeprocessor from ..util import parseBoolValue try: # pragma: no cover 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: # pragma: no cover 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: # pragma: no cover return [] # ------------------ The Main CodeHilite Class ---------------------- class CodeHilite: """ Determine language of source code, and pass it on to the Pygments highlighter. Usage: code = CodeHilite(src=some_code, lang='python') html = code.hilite() Arguments: * src: Source string or any object with a .readline attribute. * lang: String name of Pygments lexer to use for highlighting. Default: `None`. * guess_lang: Auto-detect which lexer to use. Ignored if `lang` is set to a valid value. Default: `True`. * use_pygments: Pass code to pygments for code highlighting. If `False`, the code is instead wrapped for highlighting by a JavaScript library. Default: `True`. * linenums: An alias to Pygments `linenos` formatter option. Default: `None`. * css_class: An alias to Pygments `cssclass` formatter option. Default: 'codehilite'. * lang_prefix: Prefix prepended to the language when `use_pygments` is `False`. Default: "language-". Other Options: Any other options are accepted and passed on to the lexer and formatter. Therefore, valid options include any options which are accepted by the `html` formatter or whichever lexer the code's language uses. Note that most lexers do not have any options. However, a few have very useful options, such as PHP's `startinline` option. Any invalid options are ignored without error. Formatter options: https://pygments.org/docs/formatters/#HtmlFormatter Lexer Options: https://pygments.org/docs/lexers/ Advanced Usage: code = CodeHilite( src = some_code, lang = 'php', startinline = True, # Lexer option. Snippet does not start with `). 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, **self.options) except ValueError: try: if self.guess_lang: lexer = guess_lexer(self.src, **self.options) else: lexer = get_lexer_by_name('text', **self.options) except ValueError: # pragma: no cover lexer = get_lexer_by_name('text', **self.options) formatter = get_formatter_by_name('html', **self.options) 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('{}{}'.format(self.lang_prefix, self.lang)) if self.options['linenos']: classes.append('linenums') class_str = '' if classes: class_str = ' class="{}"'.format(' '.join(classes)) return '
{}\n
\n'.format( self.options['cssclass'], class_str, txt ) def _parseHeader(self): """ Determines language of a code block from shebang line and whether the 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 identification 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: # pragma: no cover self.lang = None if m.group('path'): # path exists - restore first line lines.insert(0, fl) if self.options['linenos'] is None and m.group('shebang'): # Overridable and Shebang exists - use line numbers self.options['linenos'] = True self.options['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 code_unescape(self, text): """Unescape code.""" text = text.replace("<", "<") text = text.replace(">", ">") # Escaped '&' should be replaced at the end to avoid # conflicting with < and >. text = text.replace("&", "&") return text 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( self.code_unescape(block[0].text), tab_length=self.md.tab_length, style=self.config.pop('pygments_style', 'default'), **self.config ) 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|table|inline=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'], 'lang_prefix': [ 'language-', 'Prefix prepended to the language when use_pygments is false. Default: "language-"' ] } for key, value in kwargs.items(): if key in self.config: self.setConfig(key, value) else: # manually set unknown keywords. if isinstance(value, str): try: # Attempt to parse str as a bool value value = parseBoolValue(value, preserve_none=True) except ValueError: pass # Assume it's not a bool value. Use as-is. self.config[key] = [value, ''] 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)