1# -*- coding: utf-8 -*-
2from __future__ import unicode_literals
3import re
4import sys
5
6
7"""
8Python 3 Stuff
9=============================================================================
10"""
11PY3 = sys.version_info[0] == 3
12
13if PY3:  # pragma: no cover
14    string_type = str
15    text_type = str
16    int2str = chr
17else:  # pragma: no cover
18    string_type = basestring   # noqa
19    text_type = unicode        # noqa
20    int2str = unichr           # noqa
21
22
23"""
24Constants you might want to modify
25-----------------------------------------------------------------------------
26"""
27
28
29BLOCK_LEVEL_ELEMENTS = re.compile(
30    r"^(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul"
31    r"|script|noscript|form|fieldset|iframe|math"
32    r"|hr|hr/|style|li|dt|dd|thead|tbody"
33    r"|tr|th|td|section|footer|header|group|figure"
34    r"|figcaption|aside|article|canvas|output"
35    r"|progress|video|nav|main)$",
36    re.IGNORECASE
37)
38# Placeholders
39STX = '\u0002'  # Use STX ("Start of text") for start-of-placeholder
40ETX = '\u0003'  # Use ETX ("End of text") for end-of-placeholder
41INLINE_PLACEHOLDER_PREFIX = STX+"klzzwxh:"
42INLINE_PLACEHOLDER = INLINE_PLACEHOLDER_PREFIX + "%s" + ETX
43INLINE_PLACEHOLDER_RE = re.compile(INLINE_PLACEHOLDER % r'([0-9]+)')
44AMP_SUBSTITUTE = STX+"amp"+ETX
45HTML_PLACEHOLDER = STX + "wzxhzdk:%s" + ETX
46HTML_PLACEHOLDER_RE = re.compile(HTML_PLACEHOLDER % r'([0-9]+)')
47TAG_PLACEHOLDER = STX + "hzzhzkh:%s" + ETX
48
49
50"""
51Constants you probably do not need to change
52-----------------------------------------------------------------------------
53"""
54
55RTL_BIDI_RANGES = (
56    ('\u0590', '\u07FF'),
57    # Hebrew (0590-05FF), Arabic (0600-06FF),
58    # Syriac (0700-074F), Arabic supplement (0750-077F),
59    # Thaana (0780-07BF), Nko (07C0-07FF).
60    ('\u2D30', '\u2D7F')  # Tifinagh
61)
62
63# Extensions should use "markdown.util.etree" instead of "etree" (or do `from
64# markdown.util import etree`).  Do not import it by yourself.
65
66try:  # pragma: no cover
67    # Is the C implementation of ElementTree available?
68    import xml.etree.cElementTree as etree
69    from xml.etree.ElementTree import Comment
70    # Serializers (including ours) test with non-c Comment
71    etree.test_comment = Comment
72    if etree.VERSION < "1.0.5":
73        raise RuntimeError("cElementTree version 1.0.5 or higher is required.")
74except (ImportError, RuntimeError):  # pragma: no cover
75    # Use the Python implementation of ElementTree?
76    import xml.etree.ElementTree as etree
77    if etree.VERSION < "1.1":
78        raise RuntimeError("ElementTree version 1.1 or higher is required")
79
80
81"""
82AUXILIARY GLOBAL FUNCTIONS
83=============================================================================
84"""
85
86
87def isBlockLevel(tag):
88    """Check if the tag is a block level HTML tag."""
89    if isinstance(tag, string_type):
90        return BLOCK_LEVEL_ELEMENTS.match(tag)
91    # Some ElementTree tags are not strings, so return False.
92    return False
93
94
95def parseBoolValue(value, fail_on_errors=True, preserve_none=False):
96    """Parses a string representing bool value. If parsing was successful,
97       returns True or False. If preserve_none=True, returns True, False,
98       or None. If parsing was not successful, raises  ValueError, or, if
99       fail_on_errors=False, returns None."""
100    if not isinstance(value, string_type):
101        if preserve_none and value is None:
102            return value
103        return bool(value)
104    elif preserve_none and value.lower() == 'none':
105        return None
106    elif value.lower() in ('true', 'yes', 'y', 'on', '1'):
107        return True
108    elif value.lower() in ('false', 'no', 'n', 'off', '0', 'none'):
109        return False
110    elif fail_on_errors:
111        raise ValueError('Cannot parse bool value: %r' % value)
112
113
114"""
115MISC AUXILIARY CLASSES
116=============================================================================
117"""
118
119
120class AtomicString(text_type):
121    """A string which should not be further processed."""
122    pass
123
124
125class Processor(object):
126    def __init__(self, markdown_instance=None):
127        if markdown_instance:
128            self.markdown = markdown_instance
129
130
131class HtmlStash(object):
132    """
133    This class is used for stashing HTML objects that we extract
134    in the beginning and replace with place-holders.
135    """
136
137    def __init__(self):
138        """ Create a HtmlStash. """
139        self.html_counter = 0  # for counting inline html segments
140        self.rawHtmlBlocks = []
141        self.tag_counter = 0
142        self.tag_data = []  # list of dictionaries in the order tags appear
143
144    def store(self, html, safe=False):
145        """
146        Saves an HTML segment for later reinsertion.  Returns a
147        placeholder string that needs to be inserted into the
148        document.
149
150        Keyword arguments:
151
152        * html: an html segment
153        * safe: label an html segment as safe for safemode
154
155        Returns : a placeholder string
156
157        """
158        self.rawHtmlBlocks.append((html, safe))
159        placeholder = self.get_placeholder(self.html_counter)
160        self.html_counter += 1
161        return placeholder
162
163    def reset(self):
164        self.html_counter = 0
165        self.rawHtmlBlocks = []
166
167    def get_placeholder(self, key):
168        return HTML_PLACEHOLDER % key
169
170    def store_tag(self, tag, attrs, left_index, right_index):
171        """Store tag data and return a placeholder."""
172        self.tag_data.append({'tag': tag, 'attrs': attrs,
173                              'left_index': left_index,
174                              'right_index': right_index})
175        placeholder = TAG_PLACEHOLDER % str(self.tag_counter)
176        self.tag_counter += 1  # equal to the tag's index in self.tag_data
177        return placeholder
178