#!/usr/bin/env python """ Python Markdown =============== Python Markdown converts Markdown to HTML and can be used as a library or called from the command line. ## Basic usage as a module: import markdown md = Markdown() html = md.convert(your_text_string) ## Basic use from the command line: python markdown.py source.txt > destination.html Run "python markdown.py --help" to see more options. ## Extensions See for more information and instructions on how to extend the functionality of Python Markdown. Read that before you try modifying this file. ## Authors and License Started by [Manfred Stienstra](http://www.dwerg.net/). Continued and maintained by [Yuri Takhteyev](http://www.freewisdom.org), [Waylan Limberg](http://achinghead.com/) and [Artem Yunusov](http://blog.splyer.com). Contact: markdown@freewisdom.org Copyright 2007, 2008 The Python Markdown Project (v. 1.7 and later) Copyright 200? Django Software Foundation (OrderedDict implementation) Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b) Copyright 2004 Manfred Stienstra (the original version) License: BSD (see docs/LICENSE for details). """ version = "2.0-alpha" version_info = (2,0,0, "beta") import re import sys import codecs import htmlentitydefs import logging from logging import DEBUG, INFO, WARN, ERROR, CRITICAL from urlparse import urlparse, urlunparse """ CONSTANTS ============================================================================= """ """ Constants you might want to modify ----------------------------------------------------------------------------- """ # default logging level for command-line use COMMAND_LINE_LOGGING_LEVEL = CRITICAL TAB_LENGTH = 4 # expand tabs to this many spaces ENABLE_ATTRIBUTES = True # @id = xyz -> <... id="xyz"> SMART_EMPHASIS = True # this_or_that does not become thisorthat HTML_REMOVED_TEXT = "[HTML_REMOVED]" # text used instead of HTML in safe mode BLOCK_LEVEL_ELEMENTS = re.compile("p|div|h[1-6]|blockquote|pre|table|dl|ol|ul" +"|script|noscript|form|fieldset|iframe|math" +"|ins|del|hr|hr/|style|li|dt|dd|tr") """ Constants you probably do not need to change ----------------------------------------------------------------------------- """ RTL_BIDI_RANGES = ( (u'\u0590', u'\u07FF'), # Hebrew (0590-05FF), Arabic (0600-06FF), # Syriac (0700-074F), Arabic supplement (0750-077F), # Thaana (0780-07BF), Nko (07C0-07FF). (u'\u2D30', u'\u2D7F'), # Tifinagh ) EXECUTABLE_NAME_FOR_USAGE = "python markdown.py" """ The name used in the usage statement displayed for python versions < 2.3. (With python 2.3 and higher the usage statement is generated by optparse and uses the actual name of the executable called.) """ # Placeholders STX = u'\u0002' # Use STX ("Start of text") for start-of-placeholder ETX = u'\u0003' # Use ETX ("End of text") for end-of-placeholder HTML_PLACEHOLDER_PREFIX = STX+"wzxhzdk:" HTML_PLACEHOLDER = HTML_PLACEHOLDER_PREFIX + "%d" + ETX INLINE_PLACEHOLDER_PREFIX = STX+"klzzwxh:" INLINE_PLACEHOLDER = INLINE_PLACEHOLDER_PREFIX + "%s" + ETX AMP_SUBSTITUTE = STX+"amp"+ETX """ AUXILIARY GLOBAL FUNCTIONS ============================================================================= """ def message(level, text): """ A wrapper method for logging debug messages. """ logging.getLogger('MARKDOWN').log(level, text) def isString(s): """ Check if it's string """ return isinstance(s, unicode) or isinstance(s, str) ## Import def importETree(): """Import the best implementation of ElementTree, return a module object.""" etree_in_c = None try: # Is it Python 2.5+ with C implemenation of ElementTree installed? import xml.etree.cElementTree as etree_in_c except ImportError: try: # Is it Python 2.5+ with Python implementation of ElementTree? import xml.etree.ElementTree as etree except ImportError: try: # An earlier version of Python with cElementTree installed? import cElementTree as etree_in_c except ImportError: try: # An earlier version of Python with Python ElementTree? import elementtree.ElementTree as etree except ImportError: message(CRITICAL, "Failed to import ElementTree") sys.exit(1) if etree_in_c and etree_in_c.VERSION < "1.0": message(CRITICAL, "For cElementTree version 1.0 or higher is required.") sys.exit(1) elif etree_in_c : return etree_in_c elif etree.VERSION < "1.1": message(CRITICAL, "For ElementTree version 1.1 or higher is required") sys.exit(1) else : return etree def isBlockLevel(tag): """Check if the tag is a block level HTML tag.""" return BLOCK_LEVEL_ELEMENTS.match(tag) ATTR_RE = re.compile("\{@([^\}]*)=([^\}]*)}") # {@id=123} def handleAttributes(text, parent): """Set values of an element based on attribute definitions ({@id=123}).""" def attributeCallback(match): parent.set(match.group(1), match.group(2)) return ATTR_RE.sub(attributeCallback, text) def dequote(string): """Remove quotes from around a string.""" if ( ( string.startswith('"') and string.endswith('"')) or (string.startswith("'") and string.endswith("'")) ): return string[1:-1] else: return string """ OVERALL DESIGN ============================================================================= Markdown processing takes place in four steps: 1. A bunch of "preprocessors" munge the input text. 2. BlockParser() parses the high-level structural elements of the pre-processed text into an ElementTree. 3. A bunch of "treeprocessors" are run against the ElementTree. One such treeprocessor runs InlinePatterns against the ElementTree, detecting inline markup. 4. Some post-processors are run against the text after the ElementTree has been serialized into text. 5. The output is written to a string. Those steps are put together by the Markdown() class. The code below is organized as follows: 1. BlockParser and it's BlockProcessors - does core block parsing. 2. All the preprocessors, patterns, treeprocessors, and postprocessors. 3. Markdown class - does the high-level wrapping. """ """ CORE MARKDOWN BLOCKPARSER ============================================================================= This parser handles basic parsing of Markdown blocks. It doesn't concern itself with inline elements such as **bold** or *italics*, but rather just catches blocks, lists, quotes, etc. The BlockParser is made up of a bunch of BlockProssors, each handling a different type of block. Extensions may add/replace/remove BlockProcessors as they need to alter how markdown blocks are parsed. """ class BlockProcessor: """ Base class for block processors. Each subclass will provide the methods below to work with the source and tree. Each processor will need to define it's own ``test`` and ``run`` methods. The ``test`` method should return True or False, to indicate whether the current block should be processed by this processor. If the test passes, the parser will call the processors ``run`` method. """ def __init__(self, parser=None): self.parser = parser def lastChild(self, parent): """ Return the last child of an etree element. """ if len(parent): return parent[-1] else: return None def detab(self, text): """ Remove a tab from the front of each line of the given text. """ newtext = [] lines = text.split('\n') for line in lines: if line.startswith(' '*TAB_LENGTH): newtext.append(line[TAB_LENGTH:]) elif not line.strip(): newtext.append('') else: break return '\n'.join(newtext), '\n'.join(lines[len(newtext):]) def looseDetab(self, text): """ Remove a tab from front of lines but allowing dedented lines. """ lines = text.split('\n') for i in range(len(lines)): if lines[i].startswith(' '*TAB_LENGTH): lines[i] = lines[i][TAB_LENGTH:] return '\n'.join(lines) def test(self, parent, block): """ Test for block type. Must be overridden by subclasses. As the parser loops through processors, it will call the ``test`` method on each to determine if the given block of text is of that type. This method must return a boolean ``True`` or ``False``. The actual method of testing is left to the needs of that particular block type. It could be as simple as ``block.startswith(some_string)`` or a complex regular expression. As the block type may be different depending on the parent of the block (i.e. inside a list), the parent etree element is also provided and may be used as part of the test. Keywords: * ``parent``: A etree element which will be the parent of the block. * ``block``: A block of text from the source which has been split at blank lines. """ pass def run(self, parent, blocks): """ Run processor. Must be overridden by subclasses. When the parser determines the appropriate type of a block, the parser will call the corresponding processor's ``run`` method. This method should parse the individual lines of the block and append them to the etree. Note that both the ``parent`` and ``etree`` keywords are pointers to instances of the objects which should be edited in place. Each processor must make changes to the existing objects as there is no mechanism to return new/different objects to replace them. This means that this method should be adding SubElements or adding text to the parent, and should remove (``pop``) or add (``insert``) items to the list of blocks. Keywords: * ``parent``: A etree element which is the parent of the current block. * ``blocks``: A list of all remaining blocks of the document. """ pass class ListIndentProcessor(BlockProcessor): """ Process children of list items. Example: * a list item process this part or this part """ def test(self, parent, block): return block.startswith(' '*TAB_LENGTH) and \ (parent.tag == "li" or \ (len(parent) and parent[-1] and \ (parent[-1].tag == "ul" or parent[-1].tag == "ol") ) ) def run(self, parent, blocks): block = self.looseDetab(blocks.pop(0)) sibling = self.lastChild(parent) if parent.tag == 'li': # The parent is already a li. Just parse the child block. self.parser.parseBlocks(parent, [block]) elif len(sibling) and sibling[-1].tag == 'li': # The parent is a list (``ol`` or ``ul``) which has children. # Assume the last child li is the parent of this block. if sibling[-1].text: # If the parent li has text, that text needs to be moved to a p block = '%s\n\n%s' % (sibling[-1].text, block) sibling[-1].text = '' self.parser.parseChunk(sibling[-1], block) else: # Create a new li and parse the block with it as the parent. li = etree.SubElement(sibling, 'li') self.parser.parseBlocks(li, [block]) class CodeBlockProcessor(BlockProcessor): """ Process code blocks. """ def test(self, parent, block): return block.startswith(' '*TAB_LENGTH) def run(self, parent, blocks): sibling = self.lastChild(parent) block = blocks.pop(0) theRest = '' if sibling and sibling.tag == "pre" and len(sibling) \ and sibling[0].tag == "code": # The previous block was a code block. As blank lines do not start # new code blocks, append this block to the previous, adding back # linebreaks removed from the split into a list. code = sibling[0] block, theRest = self.detab(block) code.text = AtomicString('%s\n%s\n' % (code.text, block.rstrip())) else: # This is a new codeblock. Create the elements and insert text. pre = etree.SubElement(parent, 'pre') code = etree.SubElement(pre, 'code') block, theRest = self.detab(block) code.text = AtomicString('%s\n' % block.rstrip()) if theRest: # This block contained unindented line(s) after the first indented # line. Insert these lines as the first block of the master blocks # list for future processing. blocks.insert(0, theRest) class BlockQuoteProcessor(BlockProcessor): RE = re.compile(r'(^|\n)[ ]{0,3}>[ ](.*)') def test(self, parent, block): return bool(self.RE.search(block)) def run(self, parent, blocks): block = blocks.pop(0) m = self.RE.search(block) if m: before = block[:m.start()] # Lines before blockquote # Pass lines before blockquote in recursively for parsing forst. self.parser.parseBlocks(parent, [before]) # Remove ``> `` from begining of each line. block = '\n'.join([self.clean(line) for line in block[m.start():].split('\n')]) sibling = self.lastChild(parent) if sibling and sibling.tag == "blockquote": # Previous block was a blockquote so set that as this blocks parent quote = sibling else: # This is a new blockquote. Create a new parent element. quote = etree.SubElement(parent, 'blockquote') # Recursively parse block with blockquote as parent. self.parser.parseChunk(quote, block) def clean(self, line): """ Remove ``>`` from beginning of a line. """ m = self.RE.match(line) if line.strip() == ">": return "" elif m: return m.group(2) else: return line class OListProcessor(BlockProcessor): """ Process ordered list blocks. """ TAG = 'ol' # Detect an item (``1. item``). ``group(1)`` contains contents of item. RE = re.compile(r'^[ ]{0,3}\d+\.[ ](.*)') # Detect items on secondary lines. they can be of either list type. CHILD_RE = re.compile(r'^[ ]{0,3}((\d+\.)|[*+-])[ ](.*)') # Detect indented (nested) items of either type INDENT_RE = re.compile(r'^[ ]{4,7}((\d+\.)|[*+-])[ ].*') def test(self, parent, block): return bool(self.RE.match(block)) def run(self, parent, blocks): # Check fr multiple items in one block. items = self.get_items(blocks.pop(0)) sibling = self.lastChild(parent) if sibling and (sibling.tag == 'ol' or sibling.tag == 'ul'): # Previous block was a list item, so set that as parent lst = sibling # make sure previous item is in a p. if len(lst) and lst[-1].text and not len(lst[-1]): p = etree.SubElement(lst[-1], 'p') p.text = lst[-1].text lst[-1].text = '' # parse first block differently as it gets wrapped in a p. li = etree.SubElement(lst, 'li') self.parser.state.set('looselist') firstitem = items.pop(0) self.parser.parseBlocks(li, [firstitem]) self.parser.state.reset() else: # This is a new list so create parent with appropriate tag. lst = etree.SubElement(parent, self.TAG) self.parser.state.set('list') # Loop through items in block, recursively parsing each with the # appropriate parent. for item in items: if item.startswith(' '*TAB_LENGTH): # Item is indented. Parse with last item as parent self.parser.parseBlocks(lst[-1], [item]) else: # New item. Create li and parse with it as parent li = etree.SubElement(lst, 'li') self.parser.parseBlocks(li, [item]) self.parser.state.reset() def get_items(self, block): """ Break a block into list items. """ items = [] for line in block.split('\n'): m = self.CHILD_RE.match(line) if m: # This is a new item. Append items.append(m.group(3)) elif self.INDENT_RE.match(line): # This is an indented (possibly nested) item. if items[-1].startswith(' '*TAB_LENGTH): # Previous item was indented. Append to that item. items[-1] = '%s\n%s' % (items[-1], line) else: items.append(line) else: # This is another line of previous item. Append to that item. items[-1] = '%s\n%s' % (items[-1], line) return items class UListProcessor(OListProcessor): """ Process unordered list blocks. """ TAG = 'ul' RE = re.compile(r'^[ ]{0,3}[*+-][ ](.*)') class HashHeaderProcessor(BlockProcessor): """ Process Hash Headers. """ # Detect a header at start of any line in block RE = re.compile(r'(^|\n)(?P#{1,6})(?P
.*?)#*(\n|$)') def test(self, parent, block): return bool(self.RE.search(block)) def run(self, parent, blocks): block = blocks.pop(0) m = self.RE.search(block) if m: before = block[:m.start()] # All lines before header after = block[m.end():] # All lines after header if before: # As the header was not the first line of the block and the # lines before the header must be parsed first, # recursively parse this lines as a block. self.parser.parseBlocks(parent, [before]) # Create header using named groups from RE h = etree.SubElement(parent, 'h%d' % len(m.group('level'))) h.text = m.group('header').strip() if after: # Insert remaining lines as first block for future parsing. blocks.insert(0, after) else: # This should never happen, but just in case... message(CRITICAL, "We've got a problem header!") class SetextHeaderProcessor(BlockProcessor): """ Process Setext-style Headers. """ # Detect Setext-style header. Must be first 2 lines of block. RE = re.compile(r'^.*?\n[=-]{3,}', re.MULTILINE) def test(self, parent, block): return bool(self.RE.match(block)) def run(self, parent, blocks): lines = blocks.pop(0).split('\n') # Determine level. ``=`` is 1 and ``-`` is 2. if lines[1].startswith('='): level = 1 else: level = 2 h = etree.SubElement(parent, 'h%d' % level) h.text = lines[0].strip() if len(lines) > 2: # Block contains additional lines. Add to master blocks for later. blocks.insert(0, '\n'.join(lines[2:])) class HRProcessor(BlockProcessor): """ Process Horizontal Rules. """ RE = r'[ ]{0,3}(?P[*_-])[ ]?((?P=ch)[ ]?){2,}[ ]*' # Detect hr on any line of a block. SEARCH_RE = re.compile(r'(^|\n)%s(\n|$)' % RE) # Match a hr on a single line of text. MATCH_RE = re.compile(r'^%s$' % RE) def test(self, parent, block): return bool(self.SEARCH_RE.search(block)) def run(self, parent, blocks): lines = blocks.pop(0).split('\n') prelines = [] # Check for lines in block before hr. for line in lines: m = self.MATCH_RE.match(line) if m: break else: prelines.append(line) if len(prelines): # Recursively parse lines before hr so they get parsed first. self.parser.parseBlocks(parent, ['\n'.join(prelines)]) # create hr hr = etree.SubElement(parent, 'hr') # check for lines in block after hr. lines = lines[len(prelines)+1:] if len(lines): # Add lines after hr to master blocks for later parsing. blocks.insert(0, '\n'.join(lines)) class EmptyBlockProcessor(BlockProcessor): """ Process blocks and start with an empty line. """ # Detect a block that only contains whitespace # or only whitespace on the first line. RE = re.compile(r'^\s*\n') def test(self, parent, block): return bool(self.RE.match(block)) def run(self, parent, blocks): block = blocks.pop(0) m = self.RE.match(block) if m: # Add remaining line to master blocks for later. blocks.insert(0, block[m.end():]) sibling = self.lastChild(parent) if sibling and sibling.tag == 'pre' and sibling[0] and \ sibling[0].tag == 'code': # Last block is a codeblock. Append to preserve whitespace. sibling[0].text = AtomicString('%s/n/n/n' % sibling[0].text ) class ParagraphProcessor(BlockProcessor): """ Process Paragraph blocks. """ def test(self, parent, block): return True def run(self, parent, blocks): block = blocks.pop(0) if block.strip(): # Not a blank block. Add to parent, otherwise throw it away. if self.parser.state.isstate('list'): # The parent is a tight-list. Append to parent.text if parent.text: parent.text = '%s\n%s' % (parent.text, block) else: parent.text = block.lstrip() else: # Create a regular paragraph p = etree.SubElement(parent, 'p') p.text = block.lstrip() class State(list): """ Track the current and nested state of the parser. This utility class is used to track the state of the BlockParser and support multiple levels if nesting. It's just a simple API wrapped around a list. Each time a state is set, that state is appended to the end of the list. Each time a state is reset, that state is removed from the end of the list. Therefore, each time a state is set for a nested block, that state must be reset when we back out of that level of nesting or the state could be corrupted. While all the methods of a list object are available, only the three defined below need be used. """ def set(self, state): """ Set a new state. """ self.append(state) def reset(self): """ Step back one step in nested state. """ self.pop() def isstate(self, state): """ Test that top (current) level is of given state. """ if len(self): return self[-1] == state else: return False class BlockParser: """ Parse Markdown blocks into an ElementTree object. A wrapper class that stitches the various BlockProcessors together, looping through them and creating an ElementTree object. """ def __init__(self): self.blockprocessors = OrderedDict() self.blockprocessors['empty'] = EmptyBlockProcessor(self) self.blockprocessors['indent'] = ListIndentProcessor(self) self.blockprocessors['code'] = CodeBlockProcessor(self) self.blockprocessors['hashheader'] = HashHeaderProcessor(self) self.blockprocessors['setextheader'] = SetextHeaderProcessor(self) self.blockprocessors['hr'] = HRProcessor(self) self.blockprocessors['olist'] = OListProcessor(self) self.blockprocessors['ulist'] = UListProcessor(self) self.blockprocessors['quote'] = BlockQuoteProcessor(self) self.blockprocessors['paragraph'] = ParagraphProcessor(self) self.state = State() def parseDocument(self, lines): """ Parse a markdown document into an ElementTree. Given a list of lines, an ElementTree object (not just a parent Element) is created and the root element is passed to the parser as the parent. The ElementTree object is returned. This should only be called on an entire document, not pieces. """ # Create a ElementTree from the lines root = etree.Element("div") self.parseChunk(root, '\n'.join(lines)) return etree.ElementTree(root) def parseChunk(self, parent, text): """ Parse a chunk of markdown text and attach to given etree node. While the ``text`` argument is generally assumed to contain multiple blocks which will be split on blank lines, it could contain only one block. Generally, this method would be called by extensions when block parsing is required. The ``parent`` etree Element passed in is altered in place. Nothing is returned. """ self.parseBlocks(parent, text.split('\n\n')) def parseBlocks(self, parent, blocks): """ Process blocks of markdown text and attach to given etree node. Given a list of ``blocks``, each blockprocessor is stepped through until there are no blocks left. While an extension could potentially call this method directly, it's generally expected to be used internally. This is a public method as an extension may need to add/alter additional BlockProcessors which call this method to recursively parse a nested block. """ while blocks: for processor in self.blockprocessors.values(): if processor.test(parent, blocks[0]): processor.run(parent, blocks) break """ PRE-PROCESSORS ============================================================================= Preprocessors work on source text before we start doing anything too complicated. """ class Processor: def __init__(self, markdown_instance=None): if markdown_instance: self.markdown = markdown_instance class Preprocessor (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>"] def _get_left_tag(self, block): return block[1:].replace(">", " ", 1).split()[0].lower() def _get_right_tag(self, left_tag, block): for p in self.right_tag_patterns: tag = p % left_tag i = block.rfind(tag) if i > 2: return tag.lstrip("<").rstrip(">"), i + len(p)-2 + len(left_tag) return block.rstrip()[-len(left_tag)-2:-1].lower(), len(block) def _equal_tags(self, left_tag, right_tag): if left_tag == 'div' or 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("<"): left_tag = self._get_left_tag(block) right_tag, data_index = self._get_right_tag(left_tag, block) if data_index < len(block): text.insert(0, block[data_index:]) block = block[:data_index] if not (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[1] == "!": # is a comment block left_tag = "--" right_tag, data_index = self._get_right_tag(left_tag, block) # keep checking conditions below and maybe just append if block.rstrip().endswith(">") \ and self._equal_tags(left_tag, right_tag): new_blocks.append( self.markdown.htmlStash.store(block.strip())) continue else: #if not block[1] == "!": # if is block level tag and is not complete if 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.strip()) right_tag, data_index = self._get_right_tag(left_tag, block) if self._equal_tags(left_tag, right_tag): # if find closing tag in_tag = False new_blocks.append( self.markdown.htmlStash.store('\n\n'.join(items))) items = [] if 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. """ RE = re.compile(r'^(\ ?\ ?\ ?)\[([^\]]*)\]:\s*([^ ]*)(.*)$', re.DOTALL) def run (self, lines): new_text = []; for line in lines: m = self.RE.match(line) if m: id = m.group(2).strip().lower() t = m.group(4).strip() # potential title if not t: self.markdown.references[id] = (m.group(3), t) elif (len(t) >= 2 and (t[0] == t[-1] == "\"" or t[0] == t[-1] == "\'" or (t[0] == "(" and t[-1] == ")") ) ): self.markdown.references[id] = (m.group(3), t[1:-1]) else: new_text.append(line) else: new_text.append(line) return new_text #+ "\n" """ INLINE PATTERNS ============================================================================= Inline patterns such as *emphasis* are handled by means of auxiliary objects, one per pattern. Pattern objects must be instances of classes that extend markdown.Pattern. Each pattern object uses a single regular expression and needs support the following methods: pattern.getCompiledRegExp() # returns a regular expression pattern.handleMatch(m) # takes a match object and returns # an ElementTree element or just plain text All of python markdown's built-in patterns subclass from Pattern, but you can add additional patterns that don't. Also note that all the regular expressions used by inline must capture the whole block. For this reason, they all start with '^(.*)' and end with '(.*)!'. In case with built-in expression Pattern takes care of adding the "^(.*)" and "(.*)!". Finally, the order in which regular expressions are applied is very important - e.g. if we first replace http://.../ links with tags and _then_ try to replace inline html, we would end up with a mess. So, we apply the expressions in the following order: * escape and backticks have to go before everything else, so that we can preempt any markdown patterns by escaping them. * then we handle auto-links (must be done before inline html) * then we handle inline HTML. At this point we will simply replace all inline HTML strings with a placeholder and add the actual HTML to a hash. * then inline images (must be done before links) * then bracketed links, first regular then reference-style * finally we apply strong and emphasis """ """ The actual regular expressions for patterns ----------------------------------------------------------------------------- """ NOBRACKET = r'[^\]\[]*' BRK = ( r'\[(' + (NOBRACKET + r'(\[')*6 + (NOBRACKET+ r'\])*')*6 + NOBRACKET + r')\]' ) NOIMG = r'(?|((?:(?:\(.*?\))|[^\(\)]))*?)\s*((['"])(.*)\12)?\)''' # [text](url) or [text]() IMAGE_LINK_RE = r'\!' + BRK + r'\s*\((<.*?>|([^\)]*))\)' # ![alttxt](http://x.com/) or ![alttxt]() REFERENCE_RE = NOIMG + BRK+ r'\s*\[([^\]]*)\]' # [Google][3] IMAGE_REFERENCE_RE = r'\!' + BRK + '\s*\[([^\]]*)\]' # ![alt text][2] NOT_STRONG_RE = r'( \* )' # stand-alone * or _ AUTOLINK_RE = r'<((?:f|ht)tps?://[^>]*)>' # AUTOMAIL_RE = r'<([^> \!]*@[^> ]*)>' # HTML_RE = r'(\<([a-zA-Z/][^\>]*?|\!--.*?--)\>)' # <...> ENTITY_RE = r'(&[\#a-zA-Z0-9]*;)' # & LINE_BREAK_RE = r' \n' # two spaces at end of line LINE_BREAK_2_RE = r' $' # two spaces at end of text """ The pattern classes ----------------------------------------------------------------------------- """ class Pattern: """Base class that inline patterns subclass. """ def __init__ (self, pattern, markdown_instance=None): """ Create an instant of an inline pattern. Keyword arguments: * pattern: A regular expression that matches a pattern """ self.pattern = pattern self.compiled_re = re.compile("^(.*?)%s(.*?)$" % pattern, re.DOTALL) # Api for Markdown to pass safe_mode into instance self.safe_mode = False if markdown_instance: self.markdown = markdown_instance def getCompiledRegExp (self): """ Return a compiled regular expression. """ return self.compiled_re def handleMatch(self, m): """Return a ElementTree element from the given match. Subclasses should override this method. Keyword arguments: * m: A re match object containing a match of the pattern. """ pass def type(self): """ Return class name, to define pattern type """ return self.__class__.__name__ BasePattern = Pattern # for backward compatibility class SimpleTextPattern (Pattern): """ Return a simple text of group(2) of a Pattern. """ def handleMatch(self, m): text = m.group(2) if text == INLINE_PLACEHOLDER_PREFIX: return None return text class SimpleTagPattern (Pattern): """ Return element of type `tag` with a text attribute of group(3) of a Pattern. """ def __init__ (self, pattern, tag): Pattern.__init__(self, pattern) self.tag = tag def handleMatch(self, m): el = etree.Element(self.tag) el.text = m.group(3) return el class SubstituteTagPattern (SimpleTagPattern): """ Return a eLement of type `tag` with no children. """ def handleMatch (self, m): return etree.Element(self.tag) class BacktickPattern (Pattern): """ Return a `` element containing the matching text. """ def __init__ (self, pattern): Pattern.__init__(self, pattern) self.tag = "code" def handleMatch(self, m): el = etree.Element(self.tag) el.text = AtomicString(m.group(3).strip()) return el class DoubleTagPattern (SimpleTagPattern): """Return a ElementTree element nested in tag2 nested in tag1. Useful for strong emphasis etc. """ def handleMatch(self, m): tag1, tag2 = self.tag.split(",") el1 = etree.Element(tag1) el2 = etree.SubElement(el1, tag2) el2.text = m.group(3) return el1 class HtmlPattern (Pattern): """ Store raw inline html and return a placeholder. """ def handleMatch (self, m): rawhtml = m.group(2) inline = True place_holder = self.markdown.htmlStash.store(rawhtml) return place_holder class LinkPattern (Pattern): """ Return a link element from the given match. """ def handleMatch(self, m): el = etree.Element("a") el.text = m.group(2) title = m.group(11) href = m.group(9) if href: if href[0] == "<": href = href[1:-1] el.set("href", self.sanitize_url(href.strip())) else: el.set("href", "") if title: title = dequote(title) #.replace('"', """) el.set("title", title) return el def sanitize_url(self, url): """ Sanitize a url against xss attacks in "safe_mode". Rather than specifically blacklisting `javascript:alert("XSS")` and all its aliases (see ), we whitelist known safe url formats. Most urls contain a network location, however some are known not to (i.e.: mailto links). Script urls do not contain a location. Additionally, for `javascript:...`, the scheme would be "javascript" but some aliases will appear to `urlparse()` to have no scheme. On top of that relative links (i.e.: "foo/bar.html") have no scheme. Therefore we must check "path", "parameters", "query" and "fragment" for any literal colons. We don't check "scheme" for colons because it *should* never have any and "netloc" must allow the form: `username:password@host:port`. """ locless_schemes = ['', 'mailto', 'news'] scheme, netloc, path, params, query, fragment = url = urlparse(url) safe_url = False if netloc != '' or scheme in locless_schemes: safe_url = True for part in url[2:]: if ":" in part: safe_url = False if self.markdown.safeMode and not safe_url: return '' else: return urlunparse(url) class ImagePattern(LinkPattern): """ Return a img element from the given match. """ def handleMatch(self, m): el = etree.Element("img") src_parts = m.group(9).split() if src_parts: src = src_parts[0] if src[0] == "<" and src[-1] == ">": src = src[1:-1] el.set('src', self.sanitize_url(src)) else: el.set('src', "") if len(src_parts) > 1: el.set('title', dequote(" ".join(src_parts[1:]))) if ENABLE_ATTRIBUTES: truealt = handleAttributes(m.group(2), el) else: truealt = m.group(2) el.set('alt', truealt) return el class ReferencePattern(LinkPattern): """ Match to a stored reference and return link element. """ def handleMatch(self, m): if m.group(9): id = m.group(9).lower() else: # if we got something like "[Google][]" # we'll use "google" as the id id = m.group(2).lower() if not self.markdown.references.has_key(id): # ignore undefined refs return None href, title = self.markdown.references[id] text = m.group(2) return self.makeTag(href, title, text) def makeTag(self, href, title, text): el = etree.Element('a') el.set('href', self.sanitize_url(href)) if title: el.set('title', title) el.text = text return el class ImageReferencePattern (ReferencePattern): """ Match to a stored reference and return img element. """ def makeTag(self, href, title, text): el = etree.Element("img") el.set("src", self.sanitize_url(href)) if title: el.set("title", title) el.set("alt", text) return el class AutolinkPattern (Pattern): """ Return a link Element given an autolink (``). """ def handleMatch(self, m): el = etree.Element("a") el.set('href', m.group(2)) el.text = AtomicString(m.group(2)) return el class AutomailPattern (Pattern): """ Return a mailto link Element given an automail link (``). """ def handleMatch(self, m): el = etree.Element('a') email = m.group(2) if email.startswith("mailto:"): email = email[len("mailto:"):] def codepoint2name(code): """Return entity definition by code, or the code if not defined.""" entity = htmlentitydefs.codepoint2name.get(code) if entity: return "%s%s;" % (AMP_SUBSTITUTE, entity) else: return "%s#%d;" % (AMP_SUBSTITUTE, code) letters = [codepoint2name(ord(letter)) for letter in email] el.text = AtomicString(''.join(letters)) mailto = "mailto:" + email mailto = "".join([AMP_SUBSTITUTE + '#%d;' % ord(letter) for letter in mailto]) el.set('href', mailto) return el """ POST-PROCESSORS ============================================================================= Markdown also allows post-processors, which are similar to preprocessors in that they need to implement a "run" method. However, they are run after core processing. There are two types of post-processors: Treeprocessor and Postprocessor """ class Treeprocessor(Processor): """ Treeprocessors are run on the ElementTree object before serialization. Each Treeprocessor implements a "run" method that takes a pointer to an ElementTree, modifies it as necessary and returns an ElementTree object. Treeprocessors must extend markdown.Treeprocessor. """ def run(self, root): """ Subclasses of Treeprocessor should implement a `run` method, which takes a root ElementTree. This method can return another ElementTree object, and the existing root ElementTree will be replaced, or it can modify the current tree and return None. """ pass class InlineProcessor(Treeprocessor): """ A Treeprocessor that traverses a tree, applying inline patterns. """ def __init__ (self, md): self.__placeholder_prefix = INLINE_PLACEHOLDER_PREFIX self.__placeholder_suffix = ETX self.__placeholder_length = 4 + len(self.__placeholder_prefix) \ + len(self.__placeholder_suffix) self.__placeholder_re = re.compile(INLINE_PLACEHOLDER % r'([0-9]{4})') self.markdown = md def __makePlaceholder(self, type): """ Generate a placeholder """ id = "%04d" % len(self.stashed_nodes) hash = INLINE_PLACEHOLDER % id return hash, id def __findPlaceholder(self, data, index): """ Extract id from data string, start from index Keyword arguments: * data: string * index: index, from which we start search Returns: placeholder id and string index, after the found placeholder. """ m = self.__placeholder_re.search(data, index) if m: return m.group(1), m.end() else: return None, index + 1 def __stashNode(self, node, type): """ Add node to stash """ placeholder, id = self.__makePlaceholder(type) self.stashed_nodes[id] = node return placeholder def __handleInline(self, data, patternIndex=0): """ Process string with inline patterns and replace it with placeholders Keyword arguments: * data: A line of Markdown text * patternIndex: The index of the inlinePattern to start with Returns: String with placeholders. """ if not isinstance(data, AtomicString): startIndex = 0 while patternIndex < len(self.markdown.inlinePatterns): data, matched, startIndex = self.__applyPattern( self.markdown.inlinePatterns.value_for_index(patternIndex), data, patternIndex, startIndex) if not matched: patternIndex += 1 return data def __processElementText(self, node, subnode, isText=True): """ Process placeholders in Element.text or Element.tail of Elements popped from self.stashed_nodes. Keywords arguments: * node: parent node * subnode: processing node * isText: bool variable, True - it's text, False - it's tail Returns: None """ if isText: text = subnode.text subnode.text = None else: text = subnode.tail subnode.tail = None childResult = self.__processPlaceholders(text, subnode) if not isText and node is not subnode: pos = node.getchildren().index(subnode) node.remove(subnode) else: pos = 0 childResult.reverse() for newChild in childResult: node.insert(pos, newChild) def __processPlaceholders(self, data, parent): """ Process string with placeholders and generate ElementTree tree. Keyword arguments: * data: string with placeholders instead of ElementTree elements. * parent: Element, which contains processing inline data Returns: list with ElementTree elements with applied inline patterns. """ def linkText(text): if text: if result: if result[-1].tail: result[-1].tail += text else: result[-1].tail = text else: if parent.text: parent.text += text else: parent.text = text result = [] strartIndex = 0 while data: index = data.find(self.__placeholder_prefix, strartIndex) if index != -1: id, phEndIndex = self.__findPlaceholder(data, index) if self.stashed_nodes.has_key(id): node = self.stashed_nodes.get(id) if index > 0: text = data[strartIndex:index] linkText(text) if not isString(node): # it's Element for child in [node] + node.getchildren(): if child.tail: if child.tail.strip(): self.__processElementText(node, child, False) if child.text: if child.text.strip(): self.__processElementText(child, child) else: # it's just a string linkText(node) strartIndex = phEndIndex continue strartIndex = phEndIndex result.append(node) else: # wrong placeholder end = index + len(prefix) linkText(data[strartIndex:end]) strartIndex = end else: text = data[strartIndex:] linkText(text) data = "" return result def __applyPattern(self, pattern, data, patternIndex, startIndex=0): """ Check if the line fits the pattern, create the necessary elements, add it to stashed_nodes. Keyword arguments: * data: the text to be processed * pattern: the pattern to be checked * patternIndex: index of current pattern * startIndex: string index, from which we starting search Returns: String with placeholders instead of ElementTree elements. """ match = pattern.getCompiledRegExp().match(data[startIndex:]) leftData = data[:startIndex] if not match: return data, False, 0 node = pattern.handleMatch(match) if node is None: return data, True, len(leftData) + match.span(len(match.groups()))[0] if not isString(node): if not isinstance(node.text, AtomicString): # We need to process current node too for child in [node] + node.getchildren(): if not isString(node): if child.text: child.text = self.__handleInline(child.text, patternIndex + 1) if child.tail: child.tail = self.__handleInline(child.tail, patternIndex) placeholder = self.__stashNode(node, pattern.type()) return "%s%s%s%s" % (leftData, match.group(1), placeholder, match.groups()[-1]), True, 0 def run(self, tree): """Apply inline patterns to a parsed Markdown tree. Iterate over ElementTree, find elements with inline tag, apply inline patterns and append newly created Elements to tree. If you don't want process your data with inline paterns, instead of normal string, use subclass AtomicString: node.text = AtomicString("data won't be processed with inline patterns") Arguments: * markdownTree: ElementTree object, representing Markdown tree. Returns: ElementTree object with applied inline patterns. """ self.stashed_nodes = {} stack = [tree] while stack: currElement = stack.pop() insertQueue = [] for child in currElement.getchildren(): if child.text and not isinstance(child.text, AtomicString): text = child.text child.text = None lst = self.__processPlaceholders(self.__handleInline( text), child) stack += lst insertQueue.append((child, lst)) if child.getchildren(): stack.append(child) for element, lst in insertQueue: if element.text: element.text = handleAttributes(element.text, element) i = 0 for newChild in lst: # Processing attributes if newChild.tail: newChild.tail = handleAttributes(newChild.tail, element) if newChild.text: newChild.text = handleAttributes(newChild.text, newChild) element.insert(i, newChild) i += 1 return tree class PrettifyTreeprocessor(Treeprocessor): """Add linebreaks to the html document.""" def _prettifyETree(self, elem): """Recursively add linebreaks to ElementTree children.""" i = "\n" if isBlockLevel(elem.tag) and elem.tag not in ['code', 'pre']: if (not elem.text or not elem.text.strip()) \ and len(elem) and isBlockLevel(elem[0].tag): elem.text = i for e in elem: if isBlockLevel(e.tag): self._prettifyETree(e) if not elem.tail or not elem.tail.strip(): elem.tail = i if not elem.tail or not elem.tail.strip(): elem.tail = i def run(self, root): """.Add linebreaks to ElementTree root object.""" self._prettifyETree(root) # Do
's seperately as they are often in the middle of # inline content and missed by _prettifyETree. brs = root.getiterator('br') for br in brs: if not br.tail or not br.tail.strip(): br.tail = '\n' else: br.tail = '\n%s' % br.tail class Postprocessor(Processor): """ Postprocessors are run after the ElementTree it converted back into text. Each Postprocessor implements a "run" method that takes a pointer to a text string, modifies it as necessary and returns a text string. Postprocessors must extend markdown.Postprocessor. """ def run(self, text): """ Subclasses of Postprocessor should implement a `run` method, which takes the html document as a single text string and returns a (possibly modified) string. """ pass class RawHtmlPostprocessor(Postprocessor): """ Restore raw html to the document. """ def run(self, text): """ Iterate over html stash and restore "safe" html. """ for i in range(self.markdown.htmlStash.html_counter): html, safe = self.markdown.htmlStash.rawHtmlBlocks[i] if self.markdown.safeMode and not safe: if str(self.markdown.safeMode).lower() == 'escape': html = self.escape(html) elif str(self.markdown.safeMode).lower() == 'remove': html = '' else: html = HTML_REMOVED_TEXT if safe or not self.markdown.safeMode: text = text.replace("

%s

" % (HTML_PLACEHOLDER % i), html + "\n") text = text.replace(HTML_PLACEHOLDER % i, html) return text def escape(self, html): """ Basic html escaping """ html = html.replace('&', '&') html = html.replace('<', '<') html = html.replace('>', '>') return html.replace('"', '"') class AndSubstitutePostprocessor(Postprocessor): """ Restore valid entities """ def __init__(self): pass def run(self, text): text = text.replace(AMP_SUBSTITUTE, "&") return text """ MISC AUXILIARY CLASSES ============================================================================= """ class AtomicString(unicode): """A string which should not be further processed.""" pass class HtmlStash: """ 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=[] 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 = HTML_PLACEHOLDER % self.html_counter self.html_counter += 1 return placeholder def reset(self): self.html_counter = 0 self.rawHtmlBlocks = [] class OrderedDict(dict): """ A dictionary that keeps its keys in the order in which they're inserted. Copied from Django's SortedDict with some modifications. """ def __new__(cls, *args, **kwargs): instance = super(OrderedDict, cls).__new__(cls, *args, **kwargs) instance.keyOrder = [] return instance def __init__(self, data=None): if data is None: data = {} super(OrderedDict, self).__init__(data) if isinstance(data, dict): self.keyOrder = data.keys() else: self.keyOrder = [] for key, value in data: if key not in self.keyOrder: self.keyOrder.append(key) def __deepcopy__(self, memo): from copy import deepcopy return self.__class__([(key, deepcopy(value, memo)) for key, value in self.iteritems()]) def __setitem__(self, key, value): super(OrderedDict, self).__setitem__(key, value) if key not in self.keyOrder: self.keyOrder.append(key) def __delitem__(self, key): super(OrderedDict, self).__delitem__(key) self.keyOrder.remove(key) def __iter__(self): for k in self.keyOrder: yield k def pop(self, k, *args): result = super(OrderedDict, self).pop(k, *args) try: self.keyOrder.remove(k) except ValueError: # Key wasn't in the dictionary in the first place. No problem. pass return result def popitem(self): result = super(OrderedDict, self).popitem() self.keyOrder.remove(result[0]) return result def items(self): return zip(self.keyOrder, self.values()) def iteritems(self): for key in self.keyOrder: yield key, super(OrderedDict, self).__getitem__(key) def keys(self): return self.keyOrder[:] def iterkeys(self): return iter(self.keyOrder) def values(self): return [super(OrderedDict, self).__getitem__(k) for k in self.keyOrder] def itervalues(self): for key in self.keyOrder: yield super(OrderedDict, self).__getitem__(key) def update(self, dict_): for k, v in dict_.items(): self.__setitem__(k, v) def setdefault(self, key, default): if key not in self.keyOrder: self.keyOrder.append(key) return super(OrderedDict, self).setdefault(key, default) def value_for_index(self, index): """Return the value of the item at the given zero-based index.""" return self[self.keyOrder[index]] def insert(self, index, key, value): """Insert the key, value pair before the item with the given index.""" if key in self.keyOrder: n = self.keyOrder.index(key) del self.keyOrder[n] if n < index: index -= 1 self.keyOrder.insert(index, key) super(OrderedDict, self).__setitem__(key, value) def copy(self): """Return a copy of this object.""" # This way of initializing the copy means it works for subclasses, too. obj = self.__class__(self) obj.keyOrder = self.keyOrder[:] return obj def __repr__(self): """ Replace the normal dict.__repr__ with a version that returns the keys in their sorted order. """ return '{%s}' % ', '.join(['%r: %r' % (k, v) for k, v in self.items()]) def clear(self): super(OrderedDict, self).clear() self.keyOrder = [] def index(self, key): """ Return the index of a given key. """ return self.keyOrder.index(key) def index_for_location(self, location): """ Return index or None for a given location. """ if location == '_begin': i = 0 elif location == '_end': i = None elif location.startswith('<') or location.startswith('>'): i = self.index(location[1:]) if location.startswith('>'): if i >= len(self): # last item i = None else: i += 1 else: raise ValueError('Not a valid location: "%s". Location key ' 'must start with a ">" or "<".' % location) return i def add(self, key, value, location): """ Insert by key location. """ i = self.index_for_location(location) if i is not None: self.insert(i, key, value) else: self.__setitem__(key, value) def link(self, key, location): """ Change location of an existing item. """ n = self.keyOrder.index(key) del self.keyOrder[n] i = self.index_for_location(location) try: if i is not None: self.keyOrder.insert(i, key) else: self.keyOrder.append(key) except Error: # restore to prevent data loss and reraise self.keyOrder.insert(n, key) raise Error """ Markdown ============================================================================= """ class Markdown: """Convert Markdown to HTML.""" def __init__(self, extensions=[], extension_configs={}, safe_mode = False): """ Creates a new Markdown instance. Keyword arguments: * extensions: A list of extensions. If they are of type string, the module mdx_name.py will be loaded. If they are a subclass of markdown.Extension, they will be used as-is. * extension-configs: Configuration setting for extensions. * safe_mode: Disallow raw html. One of "remove", "replace" or "escape". """ self.parser = BlockParser() self.safeMode = safe_mode self.registeredExtensions = [] self.docType = "" self.stripTopLevelTags = True self.preprocessors = OrderedDict() self.preprocessors["html_block"] = HtmlBlockPreprocessor(self) self.preprocessors["reference"] = ReferencePreprocessor(self) # footnote preprocessor will be inserted with "amp_substitute" self.prePatterns = [] self.inlinePatterns = OrderedDict() self.inlinePatterns["backtick"] = BacktickPattern(BACKTICK_RE) self.inlinePatterns["escape"] = SimpleTextPattern(ESCAPE_RE) self.inlinePatterns["reference"] = ReferencePattern(REFERENCE_RE, self) self.inlinePatterns["link"] = LinkPattern(LINK_RE, self) self.inlinePatterns["image_link"] = ImagePattern(IMAGE_LINK_RE, self) self.inlinePatterns["image_reference"] = \ ImageReferencePattern(IMAGE_REFERENCE_RE, self) self.inlinePatterns["autolink"] = AutolinkPattern(AUTOLINK_RE, self) self.inlinePatterns["automail"] = AutomailPattern(AUTOMAIL_RE, self) self.inlinePatterns["linebreak2"] = \ SubstituteTagPattern(LINE_BREAK_2_RE, 'br') self.inlinePatterns["linebreak"] = \ SubstituteTagPattern(LINE_BREAK_RE, 'br') self.inlinePatterns["html"] = HtmlPattern(HTML_RE, self) self.inlinePatterns["entity"] = HtmlPattern(ENTITY_RE, self) self.inlinePatterns["not_strong"] = SimpleTextPattern(NOT_STRONG_RE) self.inlinePatterns["strong_em"] = \ DoubleTagPattern(STRONG_EM_RE, 'strong,em') self.inlinePatterns["strong"] = SimpleTagPattern(STRONG_RE, 'strong') self.inlinePatterns["emphasis"] = SimpleTagPattern(EMPHASIS_RE, 'em') self.inlinePatterns["emphasis2"] = \ SimpleTagPattern(EMPHASIS_2_RE, 'em') # The order of the handlers matters!!! self.references = {} self.htmlStash = HtmlStash() self.registerExtensions(extensions = extensions, configs = extension_configs) self.reset() def registerExtensions(self, extensions, configs): """ Register extensions with this instance of Markdown. Keyword aurguments: * extensions: A list of extensions, which can either be strings or objects. See the docstring on Markdown. * configs: A dictionary mapping module names to config options. """ for ext in extensions: if isinstance(ext, basestring): ext = load_extension(ext, configs.get(ext, [])) elif hasattr(ext, 'extendMarkdown'): # Looks like an Extension. # Nothing to do here. pass else: message(ERROR, "Incorrect type! Extension '%s' is " "neither a string or an Extension." %(repr(ext))) continue ext.extendMarkdown(self, globals()) def registerExtension(self, extension): """ This gets called by the extension """ self.registeredExtensions.append(extension) def reset(self): """ Resets all state variables so that we can start with a new text. """ self.htmlStash.reset() self.references.clear() for extension in self.registeredExtensions: extension.reset() def convert (self, source): """Convert markdown to serialized XHTML.""" # Fixup the source text if not source: return u"" # a blank unicode string try: source = unicode(source) except UnicodeDecodeError: message(CRITICAL, 'UnicodeDecodeError: Markdown only accepts unicode or ascii input.') return u"" source = source.replace(STX, "").replace(ETX, "") source = source.replace("\r\n", "\n").replace("\r", "\n") + "\n\n" source = re.sub(r'\n\s+\n', '\n\n', source) source = source.expandtabs(TAB_LENGTH) # Split into lines and run the line preprocessors. self.lines = source.split("\n") for prep in self.preprocessors.values(): self.lines = prep.run(self.lines) # Parse the high-level elements. root = self.parser.parseDocument(self.lines).getroot() # Run the tree-processors for treeprocessor in self.treeprocessors.values(): newRoot = treeprocessor.run(root) if newRoot: root = newRoot # Serialize _properly_. Strip top-level tags. xml, length = codecs.utf_8_decode(etree.tostring(root, encoding="utf8")) if self.stripTopLevelTags: xml = xml.strip()[44:-7] + "\n" # Run the text post-processors for pp in self.postprocessors.values(): xml = pp.run(xml) return xml.strip() def convertFile(self, input = None, output = None, encoding = None): """Converts a markdown file and returns the HTML as a unicode string. Decodes the file using the provided encoding (defaults to utf-8), passes the file content to markdown, and outputs the html to either the provided stream or the file with provided name, using the same encoding as the source file. **Note:** This is the only place that decoding and encoding of unicode takes place in Python-Markdown. (All other code is unicode-in / unicode-out.) Keyword arguments: * input: Name of source text file. * output: Name of output file. Writes to stdout if `None`. * extensions: A list of extension names (may contain config args). * encoding: Encoding of input and output files. Defaults to utf-8. * safe_mode: Disallow raw html. One of "remove", "replace" or "escape". """ encoding = encoding or "utf-8" # Read the source input_file = codecs.open(input, mode="r", encoding=encoding) text = input_file.read() input_file.close() text = text.lstrip(u'\ufeff') # remove the byte-order mark # Convert html = self.convert(text) # Write to file or stdout if type(output) == type("string"): output_file = codecs.open(output, "w", encoding=encoding) output_file.write(html) output_file.close() else: output.write(html.encode(encoding)) """ Extensions ----------------------------------------------------------------------------- """ class Extension: """ Base class for extensions to subclass. """ def __init__(self, configs = {}): """Create an instance of an Extention. Keyword arguments: * configs: A dict of configuration setting used by an Extension. """ self.config = configs def getConfig(self, key): """ Return a setting for the given key or an empty string. """ if self.config.has_key(key): return self.config[key][0] else: return "" def getConfigInfo(self): """ Return all config settings as a list of tuples. """ return [(key, self.config[key][1]) for key in self.config.keys()] def setConfig(self, key, value): """ Set a config setting for `key` with the given `value`. """ self.config[key][0] = value def extendMarkdown(self, md, md_globals): """ Add the various proccesors and patterns to the Markdown Instance. This method must be overriden by every extension. Keyword arguments: * md: The Markdown instance. * md_globals: Global variables in the markdown module namespace. """ pass def load_extension(ext_name, configs = []): """Load extension by name, then return the module. The extension name may contain arguments as part of the string in the following format: "extname(key1=value1,key2=value2)" """ # Parse extensions config params (ignore the order) configs = dict(configs) pos = ext_name.find("(") # find the first "(" if pos > 0: ext_args = ext_name[pos+1:-1] ext_name = ext_name[:pos] pairs = [x.split("=") for x in ext_args.split(",")] configs.update([(x.strip(), y.strip()) for (x, y) in pairs]) # Setup the module names ext_module = 'markdown_extensions' module_name_new_style = '.'.join([ext_module, ext_name]) module_name_old_style = '_'.join(['mdx', ext_name]) # Try loading the extention first from one place, then another try: # New style (markdown_extensons.) module = __import__(module_name_new_style, {}, {}, [ext_module]) except ImportError: try: # Old style (mdx.) module = __import__(module_name_old_style) except ImportError: pass if module : # If the module is loaded successfully, we expect it to define a # function called makeExtension() try: return module.makeExtension(configs.items()) except: message(CRITICAL, "Failed to instantiate extension '%s'" % ext_name) else: message(CRITICAL, "Failed loading extension '%s' from '%s' or '%s'" % (ext_name, module_name_new_style, module_name_old_style)) def load_extensions(ext_names): """Loads multiple extensions""" extensions = [] for ext_name in ext_names: extension = load_extension(ext_name) if extension: extensions.append(extension) return extensions # Extensions should use "markdown.etree" instead of "etree" (or do `from # markdown import etree`). Do not import it by yourself. etree = importETree() """ EXPORTED FUNCTIONS ============================================================================= Those are the two functions we really mean to export: markdown() and markdownFromFile(). """ def markdown(text, extensions = [], safe_mode = False): """Convert a markdown string to HTML and return HTML as a unicode string. This is a shortcut function for `Markdown` class to cover the most basic use case. It initializes an instance of Markdown, loads the necessary extensions and runs the parser on the given text. Keyword arguments: * text: Markdown formatted text as Unicode or ASCII string. * extensions: A list of extensions or extension names (may contain config args). * safe_mode: Disallow raw html. One of "remove", "replace" or "escape". Returns: An HTML document as a string. """ md = Markdown(extensions=load_extensions(extensions), safe_mode = safe_mode) return md.convert(text) def markdownFromFile(input = None, output = None, extensions = [], encoding = None, safe = False): """Read markdown code from a file and write it to a file or a stream.""" md = Markdown(extensions=load_extensions(extensions), safe_mode = safe) md.convertFile(input, output, encoding) """ COMMAND-LINE SPECIFIC STUFF ============================================================================= The rest of the code is specifically for handling the case where Python Markdown is called from the command line. """ OPTPARSE_WARNING = """ Python 2.3 or higher required for advanced command line options. For lower versions of Python use: %s INPUT_FILE > OUTPUT_FILE """ % EXECUTABLE_NAME_FOR_USAGE def parse_options(): """ Define and parse `optparse` options for command-line usage. """ try: optparse = __import__("optparse") except: if len(sys.argv) == 2: return {'input': sys.argv[1], 'output': None, 'safe': False, 'extensions': [], 'encoding': None }, CRITICAL else: print OPTPARSE_WARNING return None, None parser = optparse.OptionParser(usage="%prog INPUTFILE [options]") parser.add_option("-f", "--file", dest="filename", default=sys.stdout, help="write output to OUTPUT_FILE", metavar="OUTPUT_FILE") parser.add_option("-e", "--encoding", dest="encoding", help="encoding for input and output files",) parser.add_option("-q", "--quiet", default = CRITICAL, action="store_const", const=CRITICAL+10, dest="verbose", help="suppress all messages") parser.add_option("-v", "--verbose", action="store_const", const=INFO, dest="verbose", help="print info messages") parser.add_option("-s", "--safe", dest="safe", default=False, metavar="SAFE_MODE", help="safe mode ('replace', 'remove' or 'escape' user's HTML tag)") parser.add_option("--noisy", action="store_const", const=DEBUG, dest="verbose", help="print debug messages") parser.add_option("-x", "--extension", action="append", dest="extensions", help = "load extension EXTENSION", metavar="EXTENSION") (options, args) = parser.parse_args() if not len(args) == 1: parser.print_help() return None, None else: input_file = args[0] if not options.extensions: options.extensions = [] return {'input': input_file, 'output': options.filename, 'safe': options.safe, 'extensions': options.extensions, 'encoding': options.encoding }, options.verbose def command_line_run(): """Run Markdown from the command line.""" # Setup a logger manually for compatibility with Python 2.3 logger = logging.getLogger('MARKDOWN') logger.setLevel(COMMAND_LINE_LOGGING_LEVEL) logger.addHandler(logging.StreamHandler()) # Parse options and adjust logging level if necessary options, logging_level = parse_options() if not options: sys.exit(0) if logging_level: logging.getLogger('MARKDOWN').setLevel(logging_level) # Run markdownFromFile(**options) if __name__ == '__main__': command_line_run()