"""
PRE-PROCESSORS
=============================================================================
Preprocessors work on source text before we start doing anything too
complicated.
"""
import re
import util
import odict
def build_preprocessors(md_instance, **kwargs):
""" Build the default set of preprocessors used by Markdown. """
preprocessors = odict.OrderedDict()
if md_instance.safeMode != 'escape':
preprocessors["html_block"] = HtmlBlockPreprocessor(md_instance)
preprocessors["reference"] = ReferencePreprocessor(md_instance)
return preprocessors
class Preprocessor(util.Processor):
"""
Preprocessors are run after the text is broken into lines.
Each preprocessor implements a "run" method that takes a pointer to a
list of lines of the document, modifies it as necessary and returns
either the same pointer or a pointer to a new list.
Preprocessors must extend markdown.Preprocessor.
"""
def run(self, lines):
"""
Each subclass of Preprocessor should override the `run` method, which
takes the document as a list of strings split by newlines and returns
the (possibly modified) list of lines.
"""
pass
class HtmlBlockPreprocessor(Preprocessor):
"""Remove html blocks from the text and store them for later retrieval."""
right_tag_patterns = ["</%s>", "%s>"]
attrs_pattern = r"""
\s+(?P<attr>[^>"'/= ]+)=(?P<q>['"])(?P<value>.*?)(?P=q) # attr="value"
| # OR
\s+(?P<attr1>[^>"'/= ]+)=(?P<value1>[^> ]+) # attr=value
| # OR
\s+(?P<attr2>[^>"'/= ]+) # attr
"""
left_tag_pattern = r'^\<(?P<tag>[^> ]+)(?P<attrs>(%s)*)\s*\/?\>?' % attrs_pattern
attrs_re = re.compile(attrs_pattern, re.VERBOSE)
left_tag_re = re.compile(left_tag_pattern, re.VERBOSE)
markdown_in_raw = False
def _get_left_tag(self, block):
m = self.left_tag_re.match(block)
if m:
tag = m.group('tag')
raw_attrs = m.group('attrs')
attrs = {}
if raw_attrs:
for ma in self.attrs_re.finditer(raw_attrs):
if ma.group('attr'):
if ma.group('value'):
attrs[ma.group('attr').strip()] = ma.group('value')
else:
attrs[ma.group('attr').strip()] = ""
elif ma.group('attr1'):
if ma.group('value1'):
attrs[ma.group('attr1').strip()] = ma.group('value1')
else:
attrs[ma.group('attr1').strip()] = ""
elif ma.group('attr2'):
attrs[ma.group('attr2').strip()] = ""
return tag, len(m.group(0)), attrs
else:
tag = block[1:].split(">", 1)[0].lower()
return tag, len(tag)+2, {}
def _recursive_tagfind(self, ltag, rtag, start_index, block):
while 1:
i = block.find(rtag, start_index)
if i == -1:
return -1
j = block.find(ltag, start_index)
# if no ltag, or rtag found before another ltag, return index
if (j > i or j == -1):
return i + len(rtag)
# another ltag found before rtag, use end of ltag as starting
# point and search again
j = block.find('>', j)
start_index = self._recursive_tagfind(ltag, rtag, j + 1, block)
if start_index == -1:
# HTML potentially malformed- ltag has no corresponding
# rtag
return -1
def _get_right_tag(self, left_tag, left_index, block):
for p in self.right_tag_patterns:
tag = p % left_tag
i = self._recursive_tagfind("<%s" % left_tag, tag, left_index, block)
if i > 2:
return tag.lstrip("<").rstrip(">"), i
return block.rstrip()[-left_index:-1].lower(), len(block)
def _equal_tags(self, left_tag, right_tag):
if left_tag[0] in ['?', '@', '%']: # handle PHP, etc.
return True
if ("/" + left_tag) == right_tag:
return True
if (right_tag == "--" and left_tag == "--"):
return True
elif left_tag == right_tag[1:] \
and right_tag[0] == "/":
return True
else:
return False
def _is_oneliner(self, tag):
return (tag in ['hr', 'hr/'])
def run(self, lines):
text = "\n".join(lines)
new_blocks = []
text = text.split("\n\n")
items = []
left_tag = ''
right_tag = ''
in_tag = False # flag
while text:
block = text[0]
if block.startswith("\n"):
block = block[1:]
text = text[1:]
if block.startswith("\n"):
block = block[1:]
if not in_tag:
if block.startswith("<") and len(block.strip()) > 1:
if block[1] == "!":
# is a comment block
left_tag, left_index, attrs = "--", 2, {}
else:
left_tag, left_index, attrs = self._get_left_tag(block)
right_tag, data_index = self._get_right_tag(left_tag,
left_index,
block)
# keep checking conditions below and maybe just append
if data_index < len(block) \
and (util.isBlockLevel(left_tag)
or left_tag == '--'):
text.insert(0, block[data_index:])
block = block[:data_index]
if not (util.isBlockLevel(left_tag) \
or block[1] in ["!", "?", "@", "%"]):
new_blocks.append(block)
continue
if self._is_oneliner(left_tag):
new_blocks.append(block.strip())
continue
if block.rstrip().endswith(">") \
and self._equal_tags(left_tag, right_tag):
if self.markdown_in_raw and 'markdown' in attrs.keys():
start = re.sub(r'\smarkdown(=[\'"]?[^> ]*[\'"]?)?',
'', block[:left_index])
end = block[-len(right_tag)-2:]
block = block[left_index:-len(right_tag)-2]
new_blocks.append(
self.markdown.htmlStash.store(start))
new_blocks.append(block)
new_blocks.append(
self.markdown.htmlStash.store(end))
else:
new_blocks.append(
self.markdown.htmlStash.store(block.strip()))
continue
else:
# if is block level tag and is not complete
if util.isBlockLevel(left_tag) or left_tag == "--" \
and not block.rstrip().endswith(">"):
items.append(block.strip())
in_tag = True
else:
new_blocks.append(
self.markdown.htmlStash.store(block.strip()))
continue
new_blocks.append(block)
else:
items.append(block)
right_tag, data_index = self._get_right_tag(left_tag, 0, block)
if self._equal_tags(left_tag, right_tag):
# if find closing tag
if data_index < len(block):
# we have more text after right_tag
items[-1] = block[:data_index]
text.insert(0, block[data_index:])
in_tag = False
if self.markdown_in_raw and 'markdown' in attrs.keys():
start = re.sub(r'\smarkdown(=[\'"]?[^> ]*[\'"]?)?',
'', items[0][:left_index])
items[0] = items[0][left_index:]
end = items[-1][-len(right_tag)-2:]
items[-1] = items[-1][:-len(right_tag)-2]
new_blocks.append(
self.markdown.htmlStash.store(start))
new_blocks.extend(items)
new_blocks.append(
self.markdown.htmlStash.store(end))
else:
new_blocks.append(
self.markdown.htmlStash.store('\n\n'.join(items)))
items = []
if items:
if self.markdown_in_raw and 'markdown' in attrs.keys():
start = re.sub(r'\smarkdown(=[\'"]?[^> ]*[\'"]?)?',
'', items[0][:left_index])
items[0] = items[0][left_index:]
end = items[-1][-len(right_tag)-2:]
items[-1] = items[-1][:-len(right_tag)-2]
new_blocks.append(
self.markdown.htmlStash.store(start))
new_blocks.extend(items)
if end.strip():
new_blocks.append(
self.markdown.htmlStash.store(end))
else:
new_blocks.append(
self.markdown.htmlStash.store('\n\n'.join(items)))
#new_blocks.append(self.markdown.htmlStash.store('\n\n'.join(items)))
new_blocks.append('\n')
new_text = "\n\n".join(new_blocks)
return new_text.split("\n")
class ReferencePreprocessor(Preprocessor):
""" Remove reference definitions from text and store for later use. """
TITLE = r'[ ]*(\"(.*)\"|\'(.*)\'|\((.*)\))[ ]*'
RE = re.compile(r'^[ ]{0,3}\[([^\]]*)\]:\s*([^ ]*)[ ]*(%s)?$' % TITLE, re.DOTALL)
TITLE_RE = re.compile(r'^%s$' % TITLE)
def run (self, lines):
new_text = [];
while lines:
line = lines.pop(0)
m = self.RE.match(line)
if m:
id = m.group(1).strip().lower()
link = m.group(2).lstrip('<').rstrip('>')
t = m.group(5) or m.group(6) or m.group(7)
if not t:
# Check next line for title
tm = self.TITLE_RE.match(lines[0])
if tm:
lines.pop(0)
t = tm.group(2) or tm.group(3) or tm.group(4)
self.markdown.references[id] = (link, t)
else:
new_text.append(line)
return new_text #+ "\n"