Docserver: Support markdown for HTML content. Request thirdparty submission review.

third_party/markdown/util.py

+# -*- coding: utf-8 -*-
+# markdown is released under the BSD license
+# Copyright 2007, 2008 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+# 
+# All rights reserved.
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# *   Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+# *   Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+# *   Neither the name of the <organization> nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE PYTHON MARKDOWN PROJECT ''AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTORS TO THE PYTHON MARKDOWN PROJECT
+# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+
+from __future__ import unicode_literals
+import re
+import sys
+
+
+"""
+Python 3 Stuff
+=============================================================================
+"""
+PY3 = sys.version_info[0] == 3
+
+if PY3:
+    string_type = str
+    text_type = str
+    int2str = chr
+else:
+    string_type = basestring
+    text_type = unicode
+    int2str = unichr
+
+
+"""
+Constants you might want to modify
+-----------------------------------------------------------------------------
+"""
+
+BLOCK_LEVEL_ELEMENTS = re.compile("^(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul"
+                                  "|script|noscript|form|fieldset|iframe|math"
+                                  "|hr|hr/|style|li|dt|dd|thead|tbody"
+                                  "|tr|th|td|section|footer|header|group|figure"
+                                  "|figcaption|aside|article|canvas|output"
+                                  "|progress|video)$", re.IGNORECASE)
+# Placeholders
+STX = '\u0002'  # Use STX ("Start of text") for start-of-placeholder
+ETX = '\u0003'  # Use ETX ("End of text") for end-of-placeholder
+INLINE_PLACEHOLDER_PREFIX = STX+"klzzwxh:"
+INLINE_PLACEHOLDER = INLINE_PLACEHOLDER_PREFIX + "%s" + ETX
+INLINE_PLACEHOLDER_RE = re.compile(INLINE_PLACEHOLDER % r'([0-9]{4})')
+AMP_SUBSTITUTE = STX+"amp"+ETX
+
+"""
+Constants you probably do not need to change
+-----------------------------------------------------------------------------
+"""
+
+RTL_BIDI_RANGES = ( ('\u0590', '\u07FF'),
+                     # Hebrew (0590-05FF), Arabic (0600-06FF),
+                     # Syriac (0700-074F), Arabic supplement (0750-077F),
+                     # Thaana (0780-07BF), Nko (07C0-07FF).
+                    ('\u2D30', '\u2D7F'), # Tifinagh
+                    )
+
+# Extensions should use "markdown.util.etree" instead of "etree" (or do `from
+# markdown.util import etree`).  Do not import it by yourself.
+
+try: # Is the C implemenation of ElementTree available?
+    import xml.etree.cElementTree as etree
+    from xml.etree.ElementTree import Comment
+    # Serializers (including ours) test with non-c Comment
+    etree.test_comment = Comment
+    if etree.VERSION < "1.0.5":
+        raise RuntimeError("cElementTree version 1.0.5 or higher is required.")
+except (ImportError, RuntimeError):
+    # Use the Python implementation of ElementTree?
+    import xml.etree.ElementTree as etree
+    if etree.VERSION < "1.1":
+        raise RuntimeError("ElementTree version 1.1 or higher is required")
+
+
+"""
+AUXILIARY GLOBAL FUNCTIONS
+=============================================================================
+"""
+
+
+def isBlockLevel(tag):
+    """Check if the tag is a block level HTML tag."""
+    if isinstance(tag, string_type):
+        return BLOCK_LEVEL_ELEMENTS.match(tag)
+    # Some ElementTree tags are not strings, so return False.
+    return False
+
+"""
+MISC AUXILIARY CLASSES
+=============================================================================
+"""
+
+class AtomicString(text_type):
+    """A string which should not be further processed."""
+    pass
+
+
+class Processor(object):
+    def __init__(self, markdown_instance=None):
+        if markdown_instance:
+            self.markdown = markdown_instance
+
+
+class HtmlStash(object):
+    """
+    This class is used for stashing HTML objects that we extract
+    in the beginning and replace with place-holders.
+    """
+
+    def __init__ (self):
+        """ Create a HtmlStash. """
+        self.html_counter = 0 # for counting inline html segments
+        self.rawHtmlBlocks=[]
+
+    def store(self, html, safe=False):
+        """
+        Saves an HTML segment for later reinsertion.  Returns a
+        placeholder string that needs to be inserted into the
+        document.
+
+        Keyword arguments:
+
+        * html: an html segment
+        * safe: label an html segment as safe for safemode
+
+        Returns : a placeholder string
+
+        """
+        self.rawHtmlBlocks.append((html, safe))
+        placeholder = self.get_placeholder(self.html_counter)
+        self.html_counter += 1
+        return placeholder
+
+    def reset(self):
+        self.html_counter = 0
+        self.rawHtmlBlocks = []
+
+    def get_placeholder(self, key):
+        return "%swzxhzdk:%d%s" % (STX, key, ETX)
+