/demos/appengine/markdown.py
Python | 1235 lines | 1079 code | 49 blank | 107 comment | 56 complexity | 69fce96900e39cc19556e42fd96b30c4 MD5 | raw file
- #!/usr/bin/env python
- # Copyright (c) 2007-2008 ActiveState Corp.
- # License: MIT (http://www.opensource.org/licenses/mit-license.php)
- r"""A fast and complete Python implementation of Markdown.
- [from http://daringfireball.net/projects/markdown/]
- > Markdown is a text-to-HTML filter; it translates an easy-to-read /
- > easy-to-write structured text format into HTML. Markdown's text
- > format is most similar to that of plain text email, and supports
- > features such as headers, *emphasis*, code blocks, blockquotes, and
- > links.
- >
- > Markdown's syntax is designed not as a generic markup language, but
- > specifically to serve as a front-end to (X)HTML. You can use span-level
- > HTML tags anywhere in a Markdown document, and you can use block level
- > HTML tags (like <div> and <table> as well).
- Module usage:
- >>> import markdown2
- >>> markdown2.markdown("*boo!*") # or use `html = markdown_path(PATH)`
- u'<p><em>boo!</em></p>\n'
- >>> markdowner = Markdown()
- >>> markdowner.convert("*boo!*")
- u'<p><em>boo!</em></p>\n'
- >>> markdowner.convert("**boom!**")
- u'<p><strong>boom!</strong></p>\n'
- This implementation of Markdown implements the full "core" syntax plus a
- number of extras (e.g., code syntax coloring, footnotes) as described on
- <http://code.google.com/p/python-markdown2/wiki/Extras>.
- """
- cmdln_desc = """A fast and complete Python implementation of Markdown, a
- text-to-HTML conversion tool for web writers.
- """
- # Dev Notes:
- # - There is already a Python markdown processor
- # (http://www.freewisdom.org/projects/python-markdown/).
- # - Python's regex syntax doesn't have '\z', so I'm using '\Z'. I'm
- # not yet sure if there implications with this. Compare 'pydoc sre'
- # and 'perldoc perlre'.
- __version_info__ = (1, 0, 1, 14) # first three nums match Markdown.pl
- __version__ = '1.0.1.14'
- __author__ = "Trent Mick"
- import os
- import sys
- from pprint import pprint
- import re
- import logging
- try:
- from hashlib import md5
- except ImportError:
- from md5 import md5
- import optparse
- from random import random
- import codecs
- #---- Python version compat
- if sys.version_info[:2] < (2,4):
- from sets import Set as set
- def reversed(sequence):
- for i in sequence[::-1]:
- yield i
- def _unicode_decode(s, encoding, errors='xmlcharrefreplace'):
- return unicode(s, encoding, errors)
- else:
- def _unicode_decode(s, encoding, errors='strict'):
- return s.decode(encoding, errors)
- #---- globals
- DEBUG = False
- log = logging.getLogger("markdown")
- DEFAULT_TAB_WIDTH = 4
- # Table of hash values for escaped characters:
- def _escape_hash(s):
- # Lame attempt to avoid possible collision with someone actually
- # using the MD5 hexdigest of one of these chars in there text.
- # Other ideas: random.random(), uuid.uuid()
- #return md5(s).hexdigest() # Markdown.pl effectively does this.
- return 'md5-'+md5(s).hexdigest()
- g_escape_table = dict([(ch, _escape_hash(ch))
- for ch in '\\`*_{}[]()>#+-.!'])
- #---- exceptions
- class MarkdownError(Exception):
- pass
- #---- public api
- def markdown_path(path, encoding="utf-8",
- html4tags=False, tab_width=DEFAULT_TAB_WIDTH,
- safe_mode=None, extras=None, link_patterns=None,
- use_file_vars=False):
- text = codecs.open(path, 'r', encoding).read()
- return Markdown(html4tags=html4tags, tab_width=tab_width,
- safe_mode=safe_mode, extras=extras,
- link_patterns=link_patterns,
- use_file_vars=use_file_vars).convert(text)
- def markdown(text, html4tags=False, tab_width=DEFAULT_TAB_WIDTH,
- safe_mode=None, extras=None, link_patterns=None,
- use_file_vars=False):
- return Markdown(html4tags=html4tags, tab_width=tab_width,
- safe_mode=safe_mode, extras=extras,
- link_patterns=link_patterns,
- use_file_vars=use_file_vars).convert(text)
- class Markdown(object):
- # The dict of "extras" to enable in processing -- a mapping of
- # extra name to argument for the extra. Most extras do not have an
- # argument, in which case the value is None.
- #
- # This can be set via (a) subclassing and (b) the constructor
- # "extras" argument.
- extras = None
- urls = None
- titles = None
- html_blocks = None
- html_spans = None
- html_removed_text = "[HTML_REMOVED]" # for compat with markdown.py
- # Used to track when we're inside an ordered or unordered list
- # (see _ProcessListItems() for details):
- list_level = 0
- _ws_only_line_re = re.compile(r"^[ \t]+$", re.M)
- def __init__(self, html4tags=False, tab_width=4, safe_mode=None,
- extras=None, link_patterns=None, use_file_vars=False):
- if html4tags:
- self.empty_element_suffix = ">"
- else:
- self.empty_element_suffix = " />"
- self.tab_width = tab_width
- # For compatibility with earlier markdown2.py and with
- # markdown.py's safe_mode being a boolean,
- # safe_mode == True -> "replace"
- if safe_mode is True:
- self.safe_mode = "replace"
- else:
- self.safe_mode = safe_mode
- if self.extras is None:
- self.extras = {}
- elif not isinstance(self.extras, dict):
- self.extras = dict([(e, None) for e in self.extras])
- if extras:
- if not isinstance(extras, dict):
- extras = dict([(e, None) for e in extras])
- self.extras.update(extras)
- assert isinstance(self.extras, dict)
- self._instance_extras = self.extras.copy()
- self.link_patterns = link_patterns
- self.use_file_vars = use_file_vars
- self._outdent_re = re.compile(r'^(\t|[ ]{1,%d})' % tab_width, re.M)
- def reset(self):
- self.urls = {}
- self.titles = {}
- self.html_blocks = {}
- self.html_spans = {}
- self.list_level = 0
- self.extras = self._instance_extras.copy()
- if "footnotes" in self.extras:
- self.footnotes = {}
- self.footnote_ids = []
- def convert(self, text):
- """Convert the given text."""
- # Main function. The order in which other subs are called here is
- # essential. Link and image substitutions need to happen before
- # _EscapeSpecialChars(), so that any *'s or _'s in the <a>
- # and <img> tags get encoded.
- # Clear the global hashes. If we don't clear these, you get conflicts
- # from other articles when generating a page which contains more than
- # one article (e.g. an index page that shows the N most recent
- # articles):
- self.reset()
- if not isinstance(text, unicode):
- #TODO: perhaps shouldn't presume UTF-8 for string input?
- text = unicode(text, 'utf-8')
- if self.use_file_vars:
- # Look for emacs-style file variable hints.
- emacs_vars = self._get_emacs_vars(text)
- if "markdown-extras" in emacs_vars:
- splitter = re.compile("[ ,]+")
- for e in splitter.split(emacs_vars["markdown-extras"]):
- if '=' in e:
- ename, earg = e.split('=', 1)
- try:
- earg = int(earg)
- except ValueError:
- pass
- else:
- ename, earg = e, None
- self.extras[ename] = earg
- # Standardize line endings:
- text = re.sub("\r\n|\r", "\n", text)
- # Make sure $text ends with a couple of newlines:
- text += "\n\n"
- # Convert all tabs to spaces.
- text = self._detab(text)
- # Strip any lines consisting only of spaces and tabs.
- # This makes subsequent regexen easier to write, because we can
- # match consecutive blank lines with /\n+/ instead of something
- # contorted like /[ \t]*\n+/ .
- text = self._ws_only_line_re.sub("", text)
- if self.safe_mode:
- text = self._hash_html_spans(text)
- # Turn block-level HTML blocks into hash entries
- text = self._hash_html_blocks(text, raw=True)
- # Strip link definitions, store in hashes.
- if "footnotes" in self.extras:
- # Must do footnotes first because an unlucky footnote defn
- # looks like a link defn:
- # [^4]: this "looks like a link defn"
- text = self._strip_footnote_definitions(text)
- text = self._strip_link_definitions(text)
- text = self._run_block_gamut(text)
- if "footnotes" in self.extras:
- text = self._add_footnotes(text)
- text = self._unescape_special_chars(text)
- if self.safe_mode:
- text = self._unhash_html_spans(text)
- text += "\n"
- return text
- _emacs_oneliner_vars_pat = re.compile(r"-\*-\s*([^\r\n]*?)\s*-\*-", re.UNICODE)
- # This regular expression is intended to match blocks like this:
- # PREFIX Local Variables: SUFFIX
- # PREFIX mode: Tcl SUFFIX
- # PREFIX End: SUFFIX
- # Some notes:
- # - "[ \t]" is used instead of "\s" to specifically exclude newlines
- # - "(\r\n|\n|\r)" is used instead of "$" because the sre engine does
- # not like anything other than Unix-style line terminators.
- _emacs_local_vars_pat = re.compile(r"""^
- (?P<prefix>(?:[^\r\n|\n|\r])*?)
- [\ \t]*Local\ Variables:[\ \t]*
- (?P<suffix>.*?)(?:\r\n|\n|\r)
- (?P<content>.*?\1End:)
- """, re.IGNORECASE | re.MULTILINE | re.DOTALL | re.VERBOSE)
- def _get_emacs_vars(self, text):
- """Return a dictionary of emacs-style local variables.
- Parsing is done loosely according to this spec (and according to
- some in-practice deviations from this):
- http://www.gnu.org/software/emacs/manual/html_node/emacs/Specifying-File-Variables.html#Specifying-File-Variables
- """
- emacs_vars = {}
- SIZE = pow(2, 13) # 8kB
- # Search near the start for a '-*-'-style one-liner of variables.
- head = text[:SIZE]
- if "-*-" in head:
- match = self._emacs_oneliner_vars_pat.search(head)
- if match:
- emacs_vars_str = match.group(1)
- assert '\n' not in emacs_vars_str
- emacs_var_strs = [s.strip() for s in emacs_vars_str.split(';')
- if s.strip()]
- if len(emacs_var_strs) == 1 and ':' not in emacs_var_strs[0]:
- # While not in the spec, this form is allowed by emacs:
- # -*- Tcl -*-
- # where the implied "variable" is "mode". This form
- # is only allowed if there are no other variables.
- emacs_vars["mode"] = emacs_var_strs[0].strip()
- else:
- for emacs_var_str in emacs_var_strs:
- try:
- variable, value = emacs_var_str.strip().split(':', 1)
- except ValueError:
- log.debug("emacs variables error: malformed -*- "
- "line: %r", emacs_var_str)
- continue
- # Lowercase the variable name because Emacs allows "Mode"
- # or "mode" or "MoDe", etc.
- emacs_vars[variable.lower()] = value.strip()
- tail = text[-SIZE:]
- if "Local Variables" in tail:
- match = self._emacs_local_vars_pat.search(tail)
- if match:
- prefix = match.group("prefix")
- suffix = match.group("suffix")
- lines = match.group("content").splitlines(0)
- #print "prefix=%r, suffix=%r, content=%r, lines: %s"\
- # % (prefix, suffix, match.group("content"), lines)
- # Validate the Local Variables block: proper prefix and suffix
- # usage.
- for i, line in enumerate(lines):
- if not line.startswith(prefix):
- log.debug("emacs variables error: line '%s' "
- "does not use proper prefix '%s'"
- % (line, prefix))
- return {}
- # Don't validate suffix on last line. Emacs doesn't care,
- # neither should we.
- if i != len(lines)-1 and not line.endswith(suffix):
- log.debug("emacs variables error: line '%s' "
- "does not use proper suffix '%s'"
- % (line, suffix))
- return {}
- # Parse out one emacs var per line.
- continued_for = None
- for line in lines[:-1]: # no var on the last line ("PREFIX End:")
- if prefix: line = line[len(prefix):] # strip prefix
- if suffix: line = line[:-len(suffix)] # strip suffix
- line = line.strip()
- if continued_for:
- variable = continued_for
- if line.endswith('\\'):
- line = line[:-1].rstrip()
- else:
- continued_for = None
- emacs_vars[variable] += ' ' + line
- else:
- try:
- variable, value = line.split(':', 1)
- except ValueError:
- log.debug("local variables error: missing colon "
- "in local variables entry: '%s'" % line)
- continue
- # Do NOT lowercase the variable name, because Emacs only
- # allows "mode" (and not "Mode", "MoDe", etc.) in this block.
- value = value.strip()
- if value.endswith('\\'):
- value = value[:-1].rstrip()
- continued_for = variable
- else:
- continued_for = None
- emacs_vars[variable] = value
- # Unquote values.
- for var, val in emacs_vars.items():
- if len(val) > 1 and (val.startswith('"') and val.endswith('"')
- or val.startswith('"') and val.endswith('"')):
- emacs_vars[var] = val[1:-1]
- return emacs_vars
- # Cribbed from a post by Bart Lateur:
- # <http://www.nntp.perl.org/group/perl.macperl.anyperl/154>
- _detab_re = re.compile(r'(.*?)\t', re.M)
- def _detab_sub(self, match):
- g1 = match.group(1)
- return g1 + (' ' * (self.tab_width - len(g1) % self.tab_width))
- def _detab(self, text):
- r"""Remove (leading?) tabs from a file.
- >>> m = Markdown()
- >>> m._detab("\tfoo")
- ' foo'
- >>> m._detab(" \tfoo")
- ' foo'
- >>> m._detab("\t foo")
- ' foo'
- >>> m._detab(" foo")
- ' foo'
- >>> m._detab(" foo\n\tbar\tblam")
- ' foo\n bar blam'
- """
- if '\t' not in text:
- return text
- return self._detab_re.subn(self._detab_sub, text)[0]
- _block_tags_a = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del'
- _strict_tag_block_re = re.compile(r"""
- ( # save in \1
- ^ # start of line (with re.M)
- <(%s) # start tag = \2
- \b # word break
- (.*\n)*? # any number of lines, minimally matching
- </\2> # the matching end tag
- [ \t]* # trailing spaces/tabs
- (?=\n+|\Z) # followed by a newline or end of document
- )
- """ % _block_tags_a,
- re.X | re.M)
- _block_tags_b = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math'
- _liberal_tag_block_re = re.compile(r"""
- ( # save in \1
- ^ # start of line (with re.M)
- <(%s) # start tag = \2
- \b # word break
- (.*\n)*? # any number of lines, minimally matching
- .*</\2> # the matching end tag
- [ \t]* # trailing spaces/tabs
- (?=\n+|\Z) # followed by a newline or end of document
- )
- """ % _block_tags_b,
- re.X | re.M)
- def _hash_html_block_sub(self, match, raw=False):
- html = match.group(1)
- if raw and self.safe_mode:
- html = self._sanitize_html(html)
- key = _hash_text(html)
- self.html_blocks[key] = html
- return "\n\n" + key + "\n\n"
- def _hash_html_blocks(self, text, raw=False):
- """Hashify HTML blocks
- We only want to do this for block-level HTML tags, such as headers,
- lists, and tables. That's because we still want to wrap <p>s around
- "paragraphs" that are wrapped in non-block-level tags, such as anchors,
- phrase emphasis, and spans. The list of tags we're looking for is
- hard-coded.
- @param raw {boolean} indicates if these are raw HTML blocks in
- the original source. It makes a difference in "safe" mode.
- """
- if '<' not in text:
- return text
- # Pass `raw` value into our calls to self._hash_html_block_sub.
- hash_html_block_sub = _curry(self._hash_html_block_sub, raw=raw)
- # First, look for nested blocks, e.g.:
- # <div>
- # <div>
- # tags for inner block must be indented.
- # </div>
- # </div>
- #
- # The outermost tags must start at the left margin for this to match, and
- # the inner nested divs must be indented.
- # We need to do this before the next, more liberal match, because the next
- # match will start at the first `<div>` and stop at the first `</div>`.
- text = self._strict_tag_block_re.sub(hash_html_block_sub, text)
- # Now match more liberally, simply from `\n<tag>` to `</tag>\n`
- text = self._liberal_tag_block_re.sub(hash_html_block_sub, text)
- # Special case just for <hr />. It was easier to make a special
- # case than to make the other regex more complicated.
- if "<hr" in text:
- _hr_tag_re = _hr_tag_re_from_tab_width(self.tab_width)
- text = _hr_tag_re.sub(hash_html_block_sub, text)
- # Special case for standalone HTML comments:
- if "<!--" in text:
- start = 0
- while True:
- # Delimiters for next comment block.
- try:
- start_idx = text.index("<!--", start)
- except ValueError, ex:
- break
- try:
- end_idx = text.index("-->", start_idx) + 3
- except ValueError, ex:
- break
- # Start position for next comment block search.
- start = end_idx
- # Validate whitespace before comment.
- if start_idx:
- # - Up to `tab_width - 1` spaces before start_idx.
- for i in range(self.tab_width - 1):
- if text[start_idx - 1] != ' ':
- break
- start_idx -= 1
- if start_idx == 0:
- break
- # - Must be preceded by 2 newlines or hit the start of
- # the document.
- if start_idx == 0:
- pass
- elif start_idx == 1 and text[0] == '\n':
- start_idx = 0 # to match minute detail of Markdown.pl regex
- elif text[start_idx-2:start_idx] == '\n\n':
- pass
- else:
- break
- # Validate whitespace after comment.
- # - Any number of spaces and tabs.
- while end_idx < len(text):
- if text[end_idx] not in ' \t':
- break
- end_idx += 1
- # - Must be following by 2 newlines or hit end of text.
- if text[end_idx:end_idx+2] not in ('', '\n', '\n\n'):
- continue
- # Escape and hash (must match `_hash_html_block_sub`).
- html = text[start_idx:end_idx]
- if raw and self.safe_mode:
- html = self._sanitize_html(html)
- key = _hash_text(html)
- self.html_blocks[key] = html
- text = text[:start_idx] + "\n\n" + key + "\n\n" + text[end_idx:]
- if "xml" in self.extras:
- # Treat XML processing instructions and namespaced one-liner
- # tags as if they were block HTML tags. E.g., if standalone
- # (i.e. are their own paragraph), the following do not get
- # wrapped in a <p> tag:
- # <?foo bar?>
- #
- # <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="chapter_1.md"/>
- _xml_oneliner_re = _xml_oneliner_re_from_tab_width(self.tab_width)
- text = _xml_oneliner_re.sub(hash_html_block_sub, text)
- return text
- def _strip_link_definitions(self, text):
- # Strips link definitions from text, stores the URLs and titles in
- # hash references.
- less_than_tab = self.tab_width - 1
-
- # Link defs are in the form:
- # [id]: url "optional title"
- _link_def_re = re.compile(r"""
- ^[ ]{0,%d}\[(.+)\]: # id = \1
- [ \t]*
- \n? # maybe *one* newline
- [ \t]*
- <?(.+?)>? # url = \2
- [ \t]*
- (?:
- \n? # maybe one newline
- [ \t]*
- (?<=\s) # lookbehind for whitespace
- ['"(]
- ([^\n]*) # title = \3
- ['")]
- [ \t]*
- )? # title is optional
- (?:\n+|\Z)
- """ % less_than_tab, re.X | re.M | re.U)
- return _link_def_re.sub(self._extract_link_def_sub, text)
- def _extract_link_def_sub(self, match):
- id, url, title = match.groups()
- key = id.lower() # Link IDs are case-insensitive
- self.urls[key] = self._encode_amps_and_angles(url)
- if title:
- self.titles[key] = title.replace('"', '"')
- return ""
- def _extract_footnote_def_sub(self, match):
- id, text = match.groups()
- text = _dedent(text, skip_first_line=not text.startswith('\n')).strip()
- normed_id = re.sub(r'\W', '-', id)
- # Ensure footnote text ends with a couple newlines (for some
- # block gamut matches).
- self.footnotes[normed_id] = text + "\n\n"
- return ""
- def _strip_footnote_definitions(self, text):
- """A footnote definition looks like this:
- [^note-id]: Text of the note.
- May include one or more indented paragraphs.
- Where,
- - The 'note-id' can be pretty much anything, though typically it
- is the number of the footnote.
- - The first paragraph may start on the next line, like so:
-
- [^note-id]:
- Text of the note.
- """
- less_than_tab = self.tab_width - 1
- footnote_def_re = re.compile(r'''
- ^[ ]{0,%d}\[\^(.+)\]: # id = \1
- [ \t]*
- ( # footnote text = \2
- # First line need not start with the spaces.
- (?:\s*.*\n+)
- (?:
- (?:[ ]{%d} | \t) # Subsequent lines must be indented.
- .*\n+
- )*
- )
- # Lookahead for non-space at line-start, or end of doc.
- (?:(?=^[ ]{0,%d}\S)|\Z)
- ''' % (less_than_tab, self.tab_width, self.tab_width),
- re.X | re.M)
- return footnote_def_re.sub(self._extract_footnote_def_sub, text)
- _hr_res = [
- re.compile(r"^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$", re.M),
- re.compile(r"^[ ]{0,2}([ ]?\-[ ]?){3,}[ \t]*$", re.M),
- re.compile(r"^[ ]{0,2}([ ]?\_[ ]?){3,}[ \t]*$", re.M),
- ]
- def _run_block_gamut(self, text):
- # These are all the transformations that form block-level
- # tags like paragraphs, headers, and list items.
- text = self._do_headers(text)
- # Do Horizontal Rules:
- hr = "\n<hr"+self.empty_element_suffix+"\n"
- for hr_re in self._hr_res:
- text = hr_re.sub(hr, text)
- text = self._do_lists(text)
- if "pyshell" in self.extras:
- text = self._prepare_pyshell_blocks(text)
- text = self._do_code_blocks(text)
- text = self._do_block_quotes(text)
- # We already ran _HashHTMLBlocks() before, in Markdown(), but that
- # was to escape raw HTML in the original Markdown source. This time,
- # we're escaping the markup we've just created, so that we don't wrap
- # <p> tags around block-level tags.
- text = self._hash_html_blocks(text)
- text = self._form_paragraphs(text)
- return text
- def _pyshell_block_sub(self, match):
- lines = match.group(0).splitlines(0)
- _dedentlines(lines)
- indent = ' ' * self.tab_width
- s = ('\n' # separate from possible cuddled paragraph
- + indent + ('\n'+indent).join(lines)
- + '\n\n')
- return s
-
- def _prepare_pyshell_blocks(self, text):
- """Ensure that Python interactive shell sessions are put in
- code blocks -- even if not properly indented.
- """
- if ">>>" not in text:
- return text
- less_than_tab = self.tab_width - 1
- _pyshell_block_re = re.compile(r"""
- ^([ ]{0,%d})>>>[ ].*\n # first line
- ^(\1.*\S+.*\n)* # any number of subsequent lines
- ^\n # ends with a blank line
- """ % less_than_tab, re.M | re.X)
- return _pyshell_block_re.sub(self._pyshell_block_sub, text)
- def _run_span_gamut(self, text):
- # These are all the transformations that occur *within* block-level
- # tags like paragraphs, headers, and list items.
-
- text = self._do_code_spans(text)
-
- text = self._escape_special_chars(text)
-
- # Process anchor and image tags.
- text = self._do_links(text)
-
- # Make links out of things like `<http://example.com/>`
- # Must come after _do_links(), because you can use < and >
- # delimiters in inline links like [this](<url>).
- text = self._do_auto_links(text)
- if "link-patterns" in self.extras:
- text = self._do_link_patterns(text)
-
- text = self._encode_amps_and_angles(text)
-
- text = self._do_italics_and_bold(text)
-
- # Do hard breaks:
- text = re.sub(r" {2,}\n", " <br%s\n" % self.empty_element_suffix, text)
-
- return text
- # "Sorta" because auto-links are identified as "tag" tokens.
- _sorta_html_tokenize_re = re.compile(r"""
- (
- # tag
- </?
- (?:\w+) # tag name
- (?:\s+(?:[\w-]+:)?[\w-]+=(?:".*?"|'.*?'))* # attributes
- \s*/?>
- |
- # auto-link (e.g., <http://www.activestate.com/>)
- <\w+[^>]*>
- |
- <!--.*?--> # comment
- |
- <\?.*?\?> # processing instruction
- )
- """, re.X)
-
- def _escape_special_chars(self, text):
- # Python markdown note: the HTML tokenization here differs from
- # that in Markdown.pl, hence the behaviour for subtle cases can
- # differ (I believe the tokenizer here does a better job because
- # it isn't susceptible to unmatched '<' and '>' in HTML tags).
- # Note, however, that '>' is not allowed in an auto-link URL
- # here.
- escaped = []
- is_html_markup = False
- for token in self._sorta_html_tokenize_re.split(text):
- if is_html_markup:
- # Within tags/HTML-comments/auto-links, encode * and _
- # so they don't conflict with their use in Markdown for
- # italics and strong. We're replacing each such
- # character with its corresponding MD5 checksum value;
- # this is likely overkill, but it should prevent us from
- # colliding with the escape values by accident.
- escaped.append(token.replace('*', g_escape_table['*'])
- .replace('_', g_escape_table['_']))
- else:
- escaped.append(self._encode_backslash_escapes(token))
- is_html_markup = not is_html_markup
- return ''.join(escaped)
- def _hash_html_spans(self, text):
- # Used for safe_mode.
- def _is_auto_link(s):
- if ':' in s and self._auto_link_re.match(s):
- return True
- elif '@' in s and self._auto_email_link_re.match(s):
- return True
- return False
- tokens = []
- is_html_markup = False
- for token in self._sorta_html_tokenize_re.split(text):
- if is_html_markup and not _is_auto_link(token):
- sanitized = self._sanitize_html(token)
- key = _hash_text(sanitized)
- self.html_spans[key] = sanitized
- tokens.append(key)
- else:
- tokens.append(token)
- is_html_markup = not is_html_markup
- return ''.join(tokens)
- def _unhash_html_spans(self, text):
- for key, sanitized in self.html_spans.items():
- text = text.replace(key, sanitized)
- return text
- def _sanitize_html(self, s):
- if self.safe_mode == "replace":
- return self.html_removed_text
- elif self.safe_mode == "escape":
- replacements = [
- ('&', '&'),
- ('<', '<'),
- ('>', '>'),
- ]
- for before, after in replacements:
- s = s.replace(before, after)
- return s
- else:
- raise MarkdownError("invalid value for 'safe_mode': %r (must be "
- "'escape' or 'replace')" % self.safe_mode)
- _tail_of_inline_link_re = re.compile(r'''
- # Match tail of: [text](/url/) or [text](/url/ "title")
- \( # literal paren
- [ \t]*
- (?P<url> # \1
- <.*?>
- |
- .*?
- )
- [ \t]*
- ( # \2
- (['"]) # quote char = \3
- (?P<title>.*?)
- \3 # matching quote
- )? # title is optional
- \)
- ''', re.X | re.S)
- _tail_of_reference_link_re = re.compile(r'''
- # Match tail of: [text][id]
- [ ]? # one optional space
- (?:\n[ ]*)? # one optional newline followed by spaces
- \[
- (?P<id>.*?)
- \]
- ''', re.X | re.S)
- def _do_links(self, text):
- """Turn Markdown link shortcuts into XHTML <a> and <img> tags.
- This is a combination of Markdown.pl's _DoAnchors() and
- _DoImages(). They are done together because that simplified the
- approach. It was necessary to use a different approach than
- Markdown.pl because of the lack of atomic matching support in
- Python's regex engine used in $g_nested_brackets.
- """
- MAX_LINK_TEXT_SENTINEL = 3000 # markdown2 issue 24
- # `anchor_allowed_pos` is used to support img links inside
- # anchors, but not anchors inside anchors. An anchor's start
- # pos must be `>= anchor_allowed_pos`.
- anchor_allowed_pos = 0
- curr_pos = 0
- while True: # Handle the next link.
- # The next '[' is the start of:
- # - an inline anchor: [text](url "title")
- # - a reference anchor: [text][id]
- # - an inline img: ![text](url "title")
- # - a reference img: ![text][id]
- # - a footnote ref: [^id]
- # (Only if 'footnotes' extra enabled)
- # - a footnote defn: [^id]: ...
- # (Only if 'footnotes' extra enabled) These have already
- # been stripped in _strip_footnote_definitions() so no
- # need to watch for them.
- # - a link definition: [id]: url "title"
- # These have already been stripped in
- # _strip_link_definitions() so no need to watch for them.
- # - not markup: [...anything else...
- try:
- start_idx = text.index('[', curr_pos)
- except ValueError:
- break
- text_length = len(text)
- # Find the matching closing ']'.
- # Markdown.pl allows *matching* brackets in link text so we
- # will here too. Markdown.pl *doesn't* currently allow
- # matching brackets in img alt text -- we'll differ in that
- # regard.
- bracket_depth = 0
- for p in range(start_idx+1, min(start_idx+MAX_LINK_TEXT_SENTINEL,
- text_length)):
- ch = text[p]
- if ch == ']':
- bracket_depth -= 1
- if bracket_depth < 0:
- break
- elif ch == '[':
- bracket_depth += 1
- else:
- # Closing bracket not found within sentinel length.
- # This isn't markup.
- curr_pos = start_idx + 1
- continue
- link_text = text[start_idx+1:p]
- # Possibly a footnote ref?
- if "footnotes" in self.extras and link_text.startswith("^"):
- normed_id = re.sub(r'\W', '-', link_text[1:])
- if normed_id in self.footnotes:
- self.footnote_ids.append(normed_id)
- result = '<sup class="footnote-ref" id="fnref-%s">' \
- '<a href="#fn-%s">%s</a></sup>' \
- % (normed_id, normed_id, len(self.footnote_ids))
- text = text[:start_idx] + result + text[p+1:]
- else:
- # This id isn't defined, leave the markup alone.
- curr_pos = p+1
- continue
- # Now determine what this is by the remainder.
- p += 1
- if p == text_length:
- return text
- # Inline anchor or img?
- if text[p] == '(': # attempt at perf improvement
- match = self._tail_of_inline_link_re.match(text, p)
- if match:
- # Handle an inline anchor or img.
- is_img = start_idx > 0 and text[start_idx-1] == "!"
- if is_img:
- start_idx -= 1
- url, title = match.group("url"), match.group("title")
- if url and url[0] == '<':
- url = url[1:-1] # '<url>' -> 'url'
- # We've got to encode these to avoid conflicting
- # with italics/bold.
- url = url.replace('*', g_escape_table['*']) \
- .replace('_', g_escape_table['_'])
- if title:
- title_str = ' title="%s"' \
- % title.replace('*', g_escape_table['*']) \
- .replace('_', g_escape_table['_']) \
- .replace('"', '"')
- else:
- title_str = ''
- if is_img:
- result = '<img src="%s" alt="%s"%s%s' \
- % (url, link_text.replace('"', '"'),
- title_str, self.empty_element_suffix)
- curr_pos = start_idx + len(result)
- text = text[:start_idx] + result + text[match.end():]
- elif start_idx >= anchor_allowed_pos:
- result_head = '<a href="%s"%s>' % (url, title_str)
- result = '%s%s</a>' % (result_head, link_text)
- # <img> allowed from curr_pos on, <a> from
- # anchor_allowed_pos on.
- curr_pos = start_idx + len(result_head)
- anchor_allowed_pos = start_idx + len(result)
- text = text[:start_idx] + result + text[match.end():]
- else:
- # Anchor not allowed here.
- curr_pos = start_idx + 1
- continue
- # Reference anchor or img?
- else:
- match = self._tail_of_reference_link_re.match(text, p)
- if match:
- # Handle a reference-style anchor or img.
- is_img = start_idx > 0 and text[start_idx-1] == "!"
- if is_img:
- start_idx -= 1
- link_id = match.group("id").lower()
- if not link_id:
- link_id = link_text.lower() # for links like [this][]
- if link_id in self.urls:
- url = self.urls[link_id]
- # We've got to encode these to avoid conflicting
- # with italics/bold.
- url = url.replace('*', g_escape_table['*']) \
- .replace('_', g_escape_table['_'])
- title = self.titles.get(link_id)
- if title:
- title = title.replace('*', g_escape_table['*']) \
- .replace('_', g_escape_table['_'])
- title_str = ' title="%s"' % title
- else:
- title_str = ''
- if is_img:
- result = '<img src="%s" alt="%s"%s%s' \
- % (url, link_text.replace('"', '"'),
- title_str, self.empty_element_suffix)
- curr_pos = start_idx + len(result)
- text = text[:start_idx] + result + text[match.end():]
- elif start_idx >= anchor_allowed_pos:
- result = '<a href="%s"%s>%s</a>' \
- % (url, title_str, link_text)
- result_head = '<a href="%s"%s>' % (url, title_str)
- result = '%s%s</a>' % (result_head, link_text)
- # <img> allowed from curr_pos on, <a> from
- # anchor_allowed_pos on.
- curr_pos = start_idx + len(result_head)
- anchor_allowed_pos = start_idx + len(result)
- text = text[:start_idx] + result + text[match.end():]
- else:
- # Anchor not allowed here.
- curr_pos = start_idx + 1
- else:
- # This id isn't defined, leave the markup alone.
- curr_pos = match.end()
- continue
- # Otherwise, it isn't markup.
- curr_pos = start_idx + 1
- return text
- _setext_h_re = re.compile(r'^(.+)[ \t]*\n(=+|-+)[ \t]*\n+', re.M)
- def _setext_h_sub(self, match):
- n = {"=": 1, "-": 2}[match.group(2)[0]]
- demote_headers = self.extras.get("demote-headers")
- if demote_headers:
- n = min(n + demote_headers, 6)
- return "<h%d>%s</h%d>\n\n" \
- % (n, self._run_span_gamut(match.group(1)), n)
- _atx_h_re = re.compile(r'''
- ^(\#{1,6}) # \1 = string of #'s
- [ \t]*
- (.+?) # \2 = Header text
- [ \t]*
- (?<!\\) # ensure not an escaped trailing '#'
- \#* # optional closing #'s (not counted)
- \n+
- ''', re.X | re.M)
- def _atx_h_sub(self, match):
- n = len(match.group(1))
- demote_headers = self.extras.get("demote-headers")
- if demote_headers:
- n = min(n + demote_headers, 6)
- return "<h%d>%s</h%d>\n\n" \
- % (n, self._run_span_gamut(match.group(2)), n)
- def _do_headers(self, text):
- # Setext-style headers:
- # Header 1
- # ========
- #
- # Header 2
- # --------
- text = self._setext_h_re.sub(self._setext_h_sub, text)
- # atx-style headers:
- # # Header 1
- # ## Header 2
- # ## Header 2 with closing hashes ##
- # ...
- # ###### Header 6
- text = self._atx_h_re.sub(self._atx_h_sub, text)
- return text
- _marker_ul_chars = '*+-'
- _marker_any = r'(?:[%s]|\d+\.)' % _marker_ul_chars
- _marker_ul = '(?:[%s])' % _marker_ul_chars
- _marker_ol = r'(?:\d+\.)'
- def _list_sub(self, match):
- lst = match.group(1)
- lst_type = match.group(3) in self._marker_ul_chars and "ul" or "ol"
- result = self._process_list_items(lst)
- if self.list_level:
- return "<%s>\n%s</%s>\n" % (lst_type, result, lst_type)
- else:
- return "<%s>\n%s</%s>\n\n" % (lst_type, result, lst_type)
- def _do_lists(self, text):
- # Form HTML ordered (numbered) and unordered (bulleted) lists.
- for marker_pat in (self._marker_ul, self._marker_ol):
- # Re-usable pattern to match any entire ul or ol list:
- less_than_tab = self.tab_width - 1
- whole_list = r'''
- ( # \1 = whole list
- ( # \2
- [ ]{0,%d}
- (%s) # \3 = first list item marker
- [ \t]+
- )
- (?:.+?)
- ( # \4
- \Z
- |
- \n{2,}
- (?=\S)
- (?! # Negative lookahead for another list item marker
- [ \t]*
- %s[ \t]+
- )
- )
- )
- ''' % (less_than_tab, marker_pat, marker_pat)
-
- # We use a different prefix before nested lists than top-level lists.
- # See extended comment in _process_list_items().
- #
- # Note: There's a bit of duplication here. My original implementation
- # created a scalar regex pattern as the conditional result of the test on
- # $g_list_level, and then only ran the $text =~ s{...}{...}egmx
- # substitution once, using the scalar as the pattern. This worked,
- # everywhere except when running under MT on my hosting account at Pair
- # Networks. There, this caused all rebuilds to be killed by the reaper (or
- # perhaps they crashed, but that seems incredibly unlikely given that the
- # same script on the same server ran fine *except* under MT. I've spent
- # more time trying to figure out why this is happening than I'd like to
- # admit. My only guess, backed up by the fact that this workaround works,
- # is that Perl optimizes the substition when it can figure out that the
- # pattern will never change, and when this optimization isn't on, we run
- # afoul of the reaper. Thus, the slightly redundant code to that uses two
- # static s/// patterns rather than one conditional pattern.
- if self.list_level:
- sub_list_re = re.compile("^"+whole_list, re.X | re.M | re.S)
- text = sub_list_re.sub(self._list_sub, text)
- else:
- list_re = re.compile(r"(?:(?<=\n\n)|\A\n?)"+whole_list,
- re.X | re.M | re.S)
- text = list_re.sub(self._list_sub, text)
- return text
-
- _list_item_re = re.compile(r'''
- (\n)? # leading line = \1
- (^[ \t]*) # leading whitespace = \2
- (%s) [ \t]+ # list marker = \3
- ((?:.+?) # list item text = \4
- (\n{1,2})) # eols = \5
- (?= \n* (\Z | \2 (%s) [ \t]+))
- ''' % (_marker_any, _marker_any),
- re.M | re.X | re.S)
- _last_li_endswith_two_eols = False
- def _list_item_sub(self, match):
- item = match.group(4)
- leading_line = match.group(1)
- leading_space = match.group(2)
- if leading_line or "\n\n" in item or self._last_li_endswith_two_eols:
- item = self._run_block_gamut(self._outdent(item))
- else:
- # Recursion for sub-lists:
- item = self._do_lists(self._outdent(item))
- if item.endswith('\n'):
- item = item[:-1]
- item = self._run_span_gamut(item)
- self._last_li_endswith_two_eols = (len(match.group(5)) == 2)
- return "<li>%s</li>\n" % item
- def _process_list_items(self, list_str):
- # Process the contents of a single ordered or unordered list,
- # splitting it into individual list items.
-
- # The $g_list_level global keeps track of when we're inside a list.
- # Each time we enter a list, we increment it; when we leave a list,
- # we decrement. If it's zero, we're not in a list anymore.
- #
- # We do this because when we're not inside a list, we want to treat
- # something like this:
- #
- # I recommend upgrading to version
- # 8. Oops, now this line is treated
- # as a sub-list.
- #
- # As a single paragraph, despite the fact that the second line starts
- # with a digit-period-space sequence.
- #
- # Whereas when we're inside a list (or sub-list), that line will be
- # treated as the start of a sub-list. What a kludge, huh? This is
- # an aspect of Markdown's syntax that's hard to parse perfectly
- # without resorting to mind-reading. Perhaps the solution is to
- # change the syntax rules such that sub-lists must start with a
- # starting cardinal number; e.g. "1." or "a.".
- self.list_level += 1
- self._last_li_endswith_two_eols = False
- list_str = list_str.rstrip('\n') + '\n'
- list_str = self._list_item_re.sub(self._list_item_sub, list_str)
- self.list_level -= 1
- return list_str
- def _get_pygments_lexer(self, lexer_name):
- try:
- from pygments import lexers, util
- except ImportError:
- return None
- try:
- return lexers.get_lexer_by_name(lexer_name)
- except util.ClassNotFound:
- return None
- def _color_with_pygments(self, codeblock, lexer, **formatter_opts):
- import pygments
- import pygments.formatters
- class HtmlCodeFormatter(pygments.formatters.HtmlFormatter):
- def _wrap_code(self, inner):
- """A function for use in a Pygments Formatter which
- wraps in <code> tags.
- """
- yield 0, "<code>"
- for tup in inner:
- yield tup
- yield 0, "</code>"
- def wrap(self, source, outfile):
- """Return the source with a code, pre, and div."""
- return self._wrap_div(self._wrap_pre(self._wrap_code(source)))
- formatter = HtmlCodeFormatter(cssclass="codehilite", **formatter_opts)
- return pygments.highlight(codeblock, lexer, formatter)
- def _code_block_sub(self, match):
- codeblock = match.group(1)
- codeblock = self._outdent(codeblock)
- codeblock = self._detab(codeblock)
- codeblock = codeblock.lstrip('\n') # trim leading newlines
- codeblock = codeblock.rstrip() # trim trailing whitespace
- if "code-color" in self.extras and codeblock.startswith(":::"):
- lexer_name, rest = codeblock.split('\n', 1)
- lexer_name = lexer_name[3:].strip()
- lexer = self._get_pygments_lexer(lexer_name)
- codeblock = rest.lstrip("\n") # Remove lexer declaration line.
- if lexer:
- formatter_opts = self.extras['code-color'] or {}
- colored = self._color_with_pygments(codeblock, lexer,
- **formatter_opts)
- return "\n\n%s\n\n" % colored
- codeblock = self._encode_code(codeblock)
- return "\n\n<pre><code>%s\n</code></pre>\n\n" % codeblock
- def _do_code_blocks(self, text):
- """Process Markdown `<pre><code>` blocks."""
- code_block_re = re.compile(r'''
- (?:\n\n|\A)
- ( # $1 = the code block -- one or more lines, starting with a space/tab
- (?:
- (?:[ ]{%d} | \t) # Lines must start with a tab or a tab-width of spaces
- .*\n