| """ |
| 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 <a> 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 |
| """ |
| |
| import markdown |
| import re |
| from urlparse import urlparse, urlunparse |
| import sys |
| if sys.version >= "3.0": |
| from html import entities as htmlentitydefs |
| else: |
| import htmlentitydefs |
| |
| """ |
| The actual regular expressions for patterns |
| ----------------------------------------------------------------------------- |
| """ |
| |
| NOBRACKET = r'[^\]\[]*' |
| BRK = ( r'\[(' |
| + (NOBRACKET + r'(\[')*6 |
| + (NOBRACKET+ r'\])*')*6 |
| + NOBRACKET + r')\]' ) |
| NOIMG = r'(?<!\!)' |
| |
| BACKTICK_RE = r'(?<!\\)(`+)(.+?)(?<!`)\2(?!`)' # `e=f()` or ``e=f("`")`` |
| ESCAPE_RE = r'\\(.)' # \< |
| EMPHASIS_RE = r'(\*)([^\*]+)\2' # *emphasis* |
| STRONG_RE = r'(\*{2}|_{2})(.+?)\2' # **strong** |
| STRONG_EM_RE = r'(\*{3}|_{3})(.+?)\2' # ***strong*** |
| |
| if markdown.SMART_EMPHASIS: |
| EMPHASIS_2_RE = r'(?<!\w)(_)(\S.+?)\2(?!\w)' # _emphasis_ |
| else: |
| EMPHASIS_2_RE = r'(_)(.+?)\2' # _emphasis_ |
| |
| LINK_RE = NOIMG + BRK + \ |
| r'''\(\s*(<.*?>|((?:(?:\(.*?\))|[^\(\)]))*?)\s*((['"])(.*?)\12)?\)''' |
| # [text](url) or [text](<url>) |
| |
| IMAGE_LINK_RE = r'\!' + BRK + r'\s*\((<.*?>|([^\)]*))\)' |
| # ![alttxt](http://x.com/) or ![alttxt](<http://x.com/>) |
| 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?://[^>]*)>' # <http://www.123.com> |
| AUTOMAIL_RE = r'<([^> \!]*@[^> ]*)>' # <me@example.com> |
| |
| 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' $' # two spaces at end of text |
| |
| |
| def dequote(string): |
| """Remove quotes from around a string.""" |
| if ( ( string.startswith('"') and string.endswith('"')) |
| or (string.startswith("'") and string.endswith("'")) ): |
| return string[1:-1] |
| else: |
| return string |
| |
| ATTR_RE = re.compile("\{@([^\}]*)=([^\}]*)}") # {@id=123} |
| |
| def handleAttributes(text, parent): |
| """Set values of an element based on attribute definitions ({@id=123}).""" |
| def attributeCallback(match): |
| parent.set(match.group(1), match.group(2).replace('\n', ' ')) |
| return ATTR_RE.sub(attributeCallback, text) |
| |
| |
| """ |
| The pattern classes |
| ----------------------------------------------------------------------------- |
| """ |
| |
| class Pattern: |
| """Base class that inline patterns subclass. """ |
| |
| def __init__ (self, pattern, markdown_instance=None): |
| """ |
| Create an instant of an inline pattern. |
| |
| Keyword arguments: |
| |
| * pattern: A regular expression that matches a pattern |
| |
| """ |
| self.pattern = pattern |
| self.compiled_re = re.compile("^(.*?)%s(.*?)$" % 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 == markdown.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 = markdown.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 markdown.etree.Element(self.tag) |
| |
| |
| class BacktickPattern (Pattern): |
| """ Return a `<code>` element containing the matching text. """ |
| def __init__ (self, pattern): |
| Pattern.__init__(self, pattern) |
| self.tag = "code" |
| |
| def handleMatch(self, m): |
| el = markdown.etree.Element(self.tag) |
| el.text = markdown.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 = markdown.etree.Element(tag1) |
| el2 = markdown.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 = markdown.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 <http://ha.ckers.org/xss.html>), 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 = markdown.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 markdown.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 id in self.markdown.references: # 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 = markdown.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 = markdown.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 (`<http://example/com>`). """ |
| def handleMatch(self, m): |
| el = markdown.etree.Element("a") |
| el.set('href', m.group(2)) |
| el.text = markdown.AtomicString(m.group(2)) |
| return el |
| |
| class AutomailPattern (Pattern): |
| """ |
| Return a mailto link Element given an automail link (`<foo@example.com>`). |
| """ |
| def handleMatch(self, m): |
| el = markdown.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;" % (markdown.AMP_SUBSTITUTE, entity) |
| else: |
| return "%s#%d;" % (markdown.AMP_SUBSTITUTE, code) |
| |
| letters = [codepoint2name(ord(letter)) for letter in email] |
| el.text = markdown.AtomicString(''.join(letters)) |
| |
| mailto = "mailto:" + email |
| mailto = "".join([markdown.AMP_SUBSTITUTE + '#%d;' % |
| ord(letter) for letter in mailto]) |
| el.set('href', mailto) |
| return el |
| |