""" Legacy Extension for Python-Markdown ==================================== Replaces the core parser with the old one. """ import markdown, re from markdown import etree """Basic and reusable regular expressions.""" def wrapRe(raw_re) : return re.compile("^%s$" % raw_re, re.DOTALL) CORE_RE = { 'header': wrapRe(r'(#{1,6})[ \t]*(.*?)[ \t]*(#*)'), # # A title 'reference-def': wrapRe(r'(\ ?\ ?\ ?)\[([^\]]*)\]:\s*([^ ]*)(.*)'), # [Google]: http://www.google.com/ 'containsline': wrapRe(r'([-]*)$|^([=]*)'), # -----, =====, etc. 'ol': wrapRe(r'[ ]{0,3}[\d]*\.\s+(.*)'), # 1. text 'ul': wrapRe(r'[ ]{0,3}[*+-]\s+(.*)'), # "* text" 'isline1': wrapRe(r'(\**)'), # *** 'isline2': wrapRe(r'(\-*)'), # --- 'isline3': wrapRe(r'(\_*)'), # ___ 'tabbed': wrapRe(r'((\t)|( ))(.*)'), # an indented line 'quoted': wrapRe(r'[ ]{0,2}> ?(.*)'), # a quoted block ("> ...") 'containsline': re.compile(r'^([-]*)$|^([=]*)$', re.M), 'attr': re.compile("\{@([^\}]*)=([^\}]*)}") # {@id=123} } class MarkdownParser: """Parser Markdown into a ElementTree.""" def __init__(self): pass def parseDocument(self, lines): """Parse a markdown string into an ElementTree.""" # Create a ElementTree from the lines root = etree.Element("div") buffer = [] for line in lines: if line.startswith("#"): self.parseChunk(root, buffer) buffer = [line] else: buffer.append(line) self.parseChunk(root, buffer) return etree.ElementTree(root) def parseChunk(self, parent_elem, lines, inList=0, looseList=0): """Process a chunk of markdown-formatted text and attach the parse to an ElementTree node. Process a section of a source document, looking for high level structural elements like lists, block quotes, code segments, html blocks, etc. Some those then get stripped of their high level markup (e.g. get unindented) and the lower-level markup is processed recursively. Keyword arguments: * parent_elem: The ElementTree element to which the content will be added. * lines: a list of lines * inList: a level Returns: None """ # Loop through lines until none left. while lines: # Skipping empty line if not lines[0]: lines = lines[1:] continue # Check if this section starts with a list, a blockquote or # a code block. If so, process them. processFn = { 'ul': self.__processUList, 'ol': self.__processOList, 'quoted': self.__processQuote, 'tabbed': self.__processCodeBlock} for regexp in ['ul', 'ol', 'quoted', 'tabbed']: m = CORE_RE[regexp].match(lines[0]) if m: processFn[regexp](parent_elem, lines, inList) return # We are NOT looking at one of the high-level structures like # lists or blockquotes. So, it's just a regular paragraph # (though perhaps nested inside a list or something else). If # we are NOT inside a list, we just need to look for a blank # line to find the end of the block. If we ARE inside a # list, however, we need to consider that a sublist does not # need to be separated by a blank line. Rather, the following # markup is legal: # # * The top level list item # # Another paragraph of the list. This is where we are now. # * Underneath we might have a sublist. # if inList: start, lines = self.__linesUntil(lines, (lambda line: CORE_RE['ul'].match(line) or CORE_RE['ol'].match(line) or not line.strip())) self.parseChunk(parent_elem, start, inList-1, looseList=looseList) inList = inList-1 else: # Ok, so it's just a simple block test = lambda line: not line.strip() or line[0] == '>' paragraph, lines = self.__linesUntil(lines, test) if len(paragraph) and paragraph[0].startswith('#'): self.__processHeader(parent_elem, paragraph) elif len(paragraph) and CORE_RE["isline3"].match(paragraph[0]): self.__processHR(parent_elem) lines = paragraph[1:] + lines elif paragraph: self.__processParagraph(parent_elem, paragraph, inList, looseList) if lines and not lines[0].strip(): lines = lines[1:] # skip the first (blank) line def __processHR(self, parentElem): hr = etree.SubElement(parentElem, "hr") def __processHeader(self, parentElem, paragraph): m = CORE_RE['header'].match(paragraph[0]) if m: level = len(m.group(1)) h = etree.SubElement(parentElem, "h%d" % level) h.text = m.group(2).strip() else: message(CRITICAL, "We've got a problem header!") def __processParagraph(self, parentElem, paragraph, inList, looseList): if ( parentElem.tag == 'li' and not (looseList or parentElem.getchildren())): # If this is the first paragraph inside "li", don't # put

around it - append the paragraph bits directly # onto parentElem el = parentElem else: # Otherwise make a "p" element el = etree.SubElement(parentElem, "p") dump = [] # Searching for hr or header for line in paragraph: # it's hr if CORE_RE["isline3"].match(line): el.text = "\n".join(dump) self.__processHR(el) dump = [] # it's header elif line.startswith("#"): el.text = "\n".join(dump) self.__processHeader(parentElem, [line]) dump = [] else: dump.append(line) if dump: text = "\n".join(dump) el.text = text def __processUList(self, parentElem, lines, inList): self.__processList(parentElem, lines, inList, listexpr='ul', tag='ul') def __processOList(self, parentElem, lines, inList): self.__processList(parentElem, lines, inList, listexpr='ol', tag='ol') def __processList(self, parentElem, lines, inList, listexpr, tag): """ Given a list of document lines starting with a list item, finds the end of the list, breaks it up, and recursively processes each list item and the remainder of the text file. Keyword arguments: * parentElem: A ElementTree element to which the content will be added * lines: a list of lines * inList: a level Returns: None """ ul = etree.SubElement(parentElem, tag) # ul might actually be '

    ' looseList = 0 # Make a list of list items items = [] item = -1 i = 0 # a counter to keep track of where we are for line in lines: loose = 0 if not line.strip(): # If we see a blank line, this _might_ be the end of the list i += 1 loose = 1 # Find the next non-blank line for j in range(i, len(lines)): if lines[j].strip(): next = lines[j] break else: # There is no more text => end of the list break # Check if the next non-blank line is still a part of the list if ( CORE_RE[listexpr].match(next) or CORE_RE['tabbed'].match(next) ): # get rid of any white space in the line items[item].append(line.strip()) looseList = loose or looseList continue else: break # found end of the list # Now we need to detect list items (at the current level) # while also detabing child elements if necessary for expr in ['ul', 'ol', 'tabbed']: m = CORE_RE[expr].match(line) if m: if expr in ['ul', 'ol']: # We are looking at a new item #if m.group(1) : # Removed the check to allow for a blank line # at the beginning of the list item items.append([m.group(1)]) item += 1 elif expr == 'tabbed': # This line needs to be detabbed items[item].append(m.group(4)) #after the 'tab' i += 1 break else: items[item].append(line) # Just regular continuation i += 1 # added on 2006.02.25 else: i += 1 # Add the ElementTree elements for item in items: li = etree.SubElement(ul, "li") self.parseChunk(li, item, inList + 1, looseList = looseList) # Process the remaining part of the section self.parseChunk(parentElem, lines[i:], inList) def __linesUntil(self, lines, condition): """ A utility function to break a list of lines upon the first line that satisfied a condition. The condition argument should be a predicate function. """ i = -1 for line in lines: i += 1 if condition(line): break else: i += 1 return lines[:i], lines[i:] def __processQuote(self, parentElem, lines, inList): """ Given a list of document lines starting with a quote finds the end of the quote, unindents it and recursively processes the body of the quote and the remainder of the text file. Keyword arguments: * parentElem: ElementTree element to which the content will be added * lines: a list of lines * inList: a level Returns: None """ dequoted = [] i = 0 blank_line = False # allow one blank line between paragraphs for line in lines: m = CORE_RE['quoted'].match(line) if m: dequoted.append(m.group(1)) i += 1 blank_line = False elif not blank_line and line.strip() != '': dequoted.append(line) i += 1 elif not blank_line and line.strip() == '': dequoted.append(line) i += 1 blank_line = True else: break blockquote = etree.SubElement(parentElem, "blockquote") self.parseChunk(blockquote, dequoted, inList) self.parseChunk(parentElem, lines[i:], inList) def __processCodeBlock(self, parentElem, lines, inList): """ Given a list of document lines starting with a code block finds the end of the block, puts it into the ElementTree verbatim wrapped in ("
    ") and recursively processes the
            the remainder of the text file.
    
            Keyword arguments:
    
            * parentElem: ElementTree element to which the content will be added
            * lines: a list of lines
            * inList: a level
    
            Returns: None
    
            """
            detabbed, theRest = self.detectTabbed(lines)
            pre = etree.SubElement(parentElem, "pre")
            code = etree.SubElement(pre, "code")
            text = "\n".join(detabbed).rstrip()+"\n"
            code.text = markdown.AtomicString(text)
            self.parseChunk(parentElem, theRest, inList)
    
        def detectTabbed(self, lines):
            """ Find indented text and remove indent before further proccesing.
    
            Keyword arguments:
    
            * lines: an array of strings
    
            Returns: a list of post processed items and the unused
            remainder of the original list
    
            """
            items = []
            item = -1
            i = 0 # to keep track of where we are
    
            def detab(line):
                match = CORE_RE['tabbed'].match(line)
                if match:
                   return match.group(4)
    
            for line in lines:
                if line.strip(): # Non-blank line
                    line = detab(line)
                    if line:
                        items.append(line)
                        i += 1
                        continue
                    else:
                        return items, lines[i:]
    
                else: # Blank line: _maybe_ we are done.
                    i += 1 # advance
    
                    # Find the next non-blank line
                    for j in range(i, len(lines)):
                        if lines[j].strip():
                            next_line = lines[j]; break
                    else:
                        break # There is no more text; we are done.
    
                    # Check if the next non-blank line is tabbed
                    if detab(next_line): # Yes, more work to do.
                        items.append("")
                        continue
                    else:
                        break # No, we are done.
            else:
                i += 1
    
            return items, lines[i:]
    
    class HeaderPreprocessor(markdown.Preprocessor):
    
        """Replace underlined headers with hashed headers.
    
        (To avoid the need for lookahead later.)
    
        """
    
        def run (self, lines):
            i = -1
            while i+1 < len(lines):
                i = i+1
                if not lines[i].strip():
                    continue
    
                if lines[i].startswith("#"):
                    lines.insert(i+1, "\n")
    
                if (i+1 <= len(lines)
                      and lines[i+1]
                      and lines[i+1][0] in ['-', '=']):
    
                    underline = lines[i+1].strip()
    
                    if underline == "="*len(underline):
                        lines[i] = "# " + lines[i].strip()
                        lines[i+1] = ""
                    elif underline == "-"*len(underline):
                        lines[i] = "## " + lines[i].strip()
                        lines[i+1] = ""
    
            return lines
    
    
    class LinePreprocessor(markdown.Preprocessor):
        """Convert HR lines to "___" format."""
        blockquote_re = re.compile(r'^(> )+')
    
        def run (self, lines):
            for i in range(len(lines)):
                prefix = ''
                m = self.blockquote_re.search(lines[i])
                if m:
                    prefix = m.group(0)
                if self._isLine(lines[i][len(prefix):]):
                    lines[i] = prefix + "___"
            return lines
    
        def _isLine(self, block):
            """Determine if a block should be replaced with an 
    """ if block.startswith(" "): return False # a code block text = "".join([x for x in block if not x.isspace()]) if len(text) <= 2: return False for pattern in ['isline1', 'isline2', 'isline3']: m = CORE_RE[pattern].match(text) if (m and m.group(1)): return True else: return False class LegacyExtension(markdown.Extension): """ Replace Markdown's core parser. """ def extendMarkdown(self, md, md_globals): """ Set the core parser to an instance of MarkdownParser. """ md.parser = MarkdownParser() md.preprocessors.add ("header", HeaderPreprocessor(self), "