Support markdown template for html editor

third_party/markdown/extensions/codehilite.py

+"""
+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: <http://packages.python.org/Markdown/extensions/code_hilite.html>
+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 __future__ import absolute_import
+from __future__ import unicode_literals
+from . import Extension
+from ..treeprocessors import Treeprocessor
+import warnings
+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.
+
+    * 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).
+
+    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, linenums=None, guess_lang=True,
+                css_class="codehilite", lang=None, style='default',
+                noclasses=False, tab_length=4):
+        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
+
+    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.: <span class="k">).
+
+        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=self.linenums,
+                                      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('&', '&amp;')
+            txt = txt.replace('<', '&lt;')
+            txt = txt.replace('>', '&gt;')
+            txt = txt.replace('"', '&quot;')
+            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 '<pre class="%s"><code%s>%s</code></pre>\n'% \
+                        (self.css_class, class_str, txt)
+
+    def _getLang(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.
+
+        """
+
+        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>^[#]!))     # Shebang or 2 or more colons.
+            (?P<path>(?:/\w+)*[/ ])?        # Zero or 1 path
+            (?P<lang>[\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 self.linenums is None and m.group('shebang'):
+                # Overridable and Shebang exists - use line numbers
+                self.linenums = True
+        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.getiterator('pre')
+        for block in blocks:
+            children = block.getchildren()
+            if len(children) == 1 and children[0].tag == 'code':
+                code = CodeHilite(children[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.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(Extension):
+    """ Add source code hilighting to markdown codeblocks. """
+
+    def __init__(self, configs):
+        # define default configs
+        self.config = {
+            'linenums': [None, "Use lines numbers. True=yes, False=no, None=auto"],
+            'force_linenos' : [False, "Depreciated! Use 'linenums' instead. Force line numbers - Default: False"],
+            'guess_lang' : [True, "Automatic language detection - Default: True"],
+            'css_class' : ["codehilite",
+                           "Set class name for wrapper <div> - Default: codehilite"],
+            'pygments_style' : ['default', 'Pygments HTML Formatter Style (Colorscheme) - Default: default'],
+            'noclasses': [False, 'Use inline styles instead of CSS classes - Default false']
+            }
+
+        # Override defaults with user settings
+        for key, value in configs:
+            # convert strings to booleans
+            if value == 'True': value = True
+            if value == 'False': value = False
+            if value == 'None': value = None
+
+            if key == 'force_linenos':
+                warnings.warn('The "force_linenos" config setting'
+                    ' to the CodeHilite extension is deprecrecated.'
+                    ' Use "linenums" instead.', PendingDeprecationWarning)
+                if value:
+                    # Carry 'force_linenos' over to new 'linenos'.
+                    self.setConfig('linenums', True)
+
+            self.setConfig(key, value)
+
+    def extendMarkdown(self, md, md_globals):
+        """ Add HilitePostprocessor to Markdown instance. """
+        hiliter = HiliteTreeprocessor(md)
+        hiliter.config = self.getConfigs()
+        md.treeprocessors.add("hilite", hiliter, "<inline")
+
+        md.registerExtension(self)
+
+
+def makeExtension(configs={}):
+  return CodeHiliteExtension(configs=configs)
+