Re-land "Check in a simple pure-python based Markdown previewer."
This re-lands #352450 with a fix to make checklicenses.py happy.
R=thestig@chromium.org
TBR=jam@chromium.org
Review URL: https://codereview.chromium.org/1392733002
Cr-Original-Commit-Position: refs/heads/master@{#352731}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 27c171cd168807f85b95ae8aaa797bda02eff319
diff --git a/markdown/util.py b/markdown/util.py
new file mode 100644
index 0000000..d3d48f0
--- /dev/null
+++ b/markdown/util.py
@@ -0,0 +1,177 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+import re
+import sys
+
+
+"""
+Python 3 Stuff
+=============================================================================
+"""
+PY3 = sys.version_info[0] == 3
+
+if PY3: # pragma: no cover
+ string_type = str
+ text_type = str
+ int2str = chr
+else: # pragma: no cover
+ string_type = basestring # noqa
+ text_type = unicode # noqa
+ int2str = unichr # noqa
+
+
+"""
+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|nav)$",
+ 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]+)')
+AMP_SUBSTITUTE = STX+"amp"+ETX
+HTML_PLACEHOLDER = STX + "wzxhzdk:%s" + ETX
+HTML_PLACEHOLDER_RE = re.compile(HTML_PLACEHOLDER % r'([0-9]+)')
+TAG_PLACEHOLDER = STX + "hzzhzkh:%s" + 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: # pragma: no cover
+ # Is the C implementation 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): # pragma: no cover
+ # 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
+
+
+def parseBoolValue(value, fail_on_errors=True, preserve_none=False):
+ """Parses a string representing bool value. If parsing was successful,
+ returns True or False. If preserve_none=True, returns True, False,
+ or None. If parsing was not successful, raises ValueError, or, if
+ fail_on_errors=False, returns None."""
+ if not isinstance(value, string_type):
+ if preserve_none and value is None:
+ return value
+ return bool(value)
+ elif preserve_none and value.lower() == 'none':
+ return None
+ elif value.lower() in ('true', 'yes', 'y', 'on', '1'):
+ return True
+ elif value.lower() in ('false', 'no', 'n', 'off', '0', 'none'):
+ return False
+ elif fail_on_errors:
+ raise ValueError('Cannot parse bool value: %r' % value)
+
+
+"""
+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 = []
+ self.tag_counter = 0
+ self.tag_data = [] # list of dictionaries in the order tags appear
+
+ 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 HTML_PLACEHOLDER % key
+
+ def store_tag(self, tag, attrs, left_index, right_index):
+ """Store tag data and return a placeholder."""
+ self.tag_data.append({'tag': tag, 'attrs': attrs,
+ 'left_index': left_index,
+ 'right_index': right_index})
+ placeholder = TAG_PLACEHOLDER % str(self.tag_counter)
+ self.tag_counter += 1 # equal to the tag's index in self.tag_data
+ return placeholder