Revert 243980 "Docserver: Support markdown for HTML content."

trunk/src/third_party/markdown/extensions/footnotes.py

-"""
-========================= FOOTNOTES =================================
-
-This section adds footnote handling to markdown.  It can be used as
-an example for extending python-markdown with relatively complex
-functionality.  While in this case the extension is included inside
-the module itself, it could just as easily be added from outside the
-module.  Not that all markdown classes above are ignorant about
-footnotes.  All footnote functionality is provided separately and
-then added to the markdown instance at the run time.
-
-Footnote functionality is attached by calling extendMarkdown()
-method of FootnoteExtension.  The method also registers the
-extension to allow it's state to be reset by a call to reset()
-method.
-
-Example:
-    Footnotes[^1] have a label[^label] and a definition[^!DEF].
-
-    [^1]: This is a footnote
-    [^label]: A footnote on "label"
-    [^!DEF]: The footnote for definition
-
-"""
-
-from __future__ import absolute_import
-from __future__ import unicode_literals
-from . import Extension
-from ..preprocessors import Preprocessor
-from ..inlinepatterns import Pattern
-from ..treeprocessors import Treeprocessor
-from ..postprocessors import Postprocessor
-from ..util import etree, text_type
-from ..odict import OrderedDict
-import re
-
-FN_BACKLINK_TEXT = "zz1337820767766393qq"
-NBSP_PLACEHOLDER =  "qq3936677670287331zz"
-DEF_RE = re.compile(r'[ ]{0,3}\[\^([^\]]*)\]:\s*(.*)')
-TABBED_RE = re.compile(r'((\t)|(    ))(.*)')
-
-class FootnoteExtension(Extension):
-    """ Footnote Extension. """
-
-    def __init__ (self, configs):
-        """ Setup configs. """
-        self.config = {'PLACE_MARKER':
-                       ["///Footnotes Go Here///",
-                        "The text string that marks where the footnotes go"],
-                       'UNIQUE_IDS':
-                       [False,
-                        "Avoid name collisions across "
-                        "multiple calls to reset()."],
-                       "BACKLINK_TEXT":
-                       ["↩",
-                        "The text string that links from the footnote to the reader's place."]
-                       }
-
-        for key, value in configs:
-            self.config[key][0] = value
-
-        # In multiple invocations, emit links that don't get tangled.
-        self.unique_prefix = 0
-
-        self.reset()
-
-    def extendMarkdown(self, md, md_globals):
-        """ Add pieces to Markdown. """
-        md.registerExtension(self)
-        self.parser = md.parser
-        self.md = md
-        self.sep = ':'
-        if self.md.output_format in ['html5', 'xhtml5']:
-            self.sep = '-'
-        # Insert a preprocessor before ReferencePreprocessor
-        md.preprocessors.add("footnote", FootnotePreprocessor(self),
-                             "<reference")
-        # Insert an inline pattern before ImageReferencePattern
-        FOOTNOTE_RE = r'\[\^([^\]]*)\]' # blah blah [^1] blah
-        md.inlinePatterns.add("footnote", FootnotePattern(FOOTNOTE_RE, self),
-                              "<reference")
-        # Insert a tree-processor that would actually add the footnote div
-        # This must be before all other treeprocessors (i.e., inline and 
-        # codehilite) so they can run on the the contents of the div.
-        md.treeprocessors.add("footnote", FootnoteTreeprocessor(self),
-                                 "_begin")
-        # Insert a postprocessor after amp_substitute oricessor
-        md.postprocessors.add("footnote", FootnotePostprocessor(self),
-                                  ">amp_substitute")
-
-    def reset(self):
-        """ Clear the footnotes on reset, and prepare for a distinct document. """
-        self.footnotes = OrderedDict()
-        self.unique_prefix += 1
-
-    def findFootnotesPlaceholder(self, root):
-        """ Return ElementTree Element that contains Footnote placeholder. """
-        def finder(element):
-            for child in element:
-                if child.text:
-                    if child.text.find(self.getConfig("PLACE_MARKER")) > -1:
-                        return child, element, True
-                if child.tail:
-                    if child.tail.find(self.getConfig("PLACE_MARKER")) > -1:
-                        return child, element, False
-                finder(child)
-            return None
-                
-        res = finder(root)
-        return res
-
-    def setFootnote(self, id, text):
-        """ Store a footnote for later retrieval. """
-        self.footnotes[id] = text
-
-    def makeFootnoteId(self, id):
-        """ Return footnote link id. """
-        if self.getConfig("UNIQUE_IDS"):
-            return 'fn%s%d-%s' % (self.sep, self.unique_prefix, id)
-        else:
-            return 'fn%s%s' % (self.sep, id)
-
-    def makeFootnoteRefId(self, id):
-        """ Return footnote back-link id. """
-        if self.getConfig("UNIQUE_IDS"):
-            return 'fnref%s%d-%s' % (self.sep, self.unique_prefix, id)
-        else:
-            return 'fnref%s%s' % (self.sep, id)
-
-    def makeFootnotesDiv(self, root):
-        """ Return div of footnotes as et Element. """
-
-        if not list(self.footnotes.keys()):
-            return None
-
-        div = etree.Element("div")
-        div.set('class', 'footnote')
-        etree.SubElement(div, "hr")
-        ol = etree.SubElement(div, "ol")
-
-        for id in self.footnotes.keys():
-            li = etree.SubElement(ol, "li")
-            li.set("id", self.makeFootnoteId(id))
-            self.parser.parseChunk(li, self.footnotes[id])
-            backlink = etree.Element("a")
-            backlink.set("href", "#" + self.makeFootnoteRefId(id))
-            if self.md.output_format not in ['html5', 'xhtml5']:
-                backlink.set("rev", "footnote") # Invalid in HTML5
-            backlink.set("class", "footnote-backref")
-            backlink.set("title", "Jump back to footnote %d in the text" % \
-                            (self.footnotes.index(id)+1))
-            backlink.text = FN_BACKLINK_TEXT
-
-            if li.getchildren():
-                node = li[-1]
-                if node.tag == "p":
-                    node.text = node.text + NBSP_PLACEHOLDER
-                    node.append(backlink)
-                else:
-                    p = etree.SubElement(li, "p")
-                    p.append(backlink)
-        return div
-
-
-class FootnotePreprocessor(Preprocessor):
-    """ Find all footnote references and store for later use. """
-
-    def __init__ (self, footnotes):
-        self.footnotes = footnotes
-
-    def run(self, lines):
-        """
-        Loop through lines and find, set, and remove footnote definitions.
-
-        Keywords:
-
-        * lines: A list of lines of text
-
-        Return: A list of lines of text with footnote definitions removed.
-
-        """
-        newlines = []
-        i = 0
-        while True:
-            m = DEF_RE.match(lines[i])
-            if m:
-                fn, _i = self.detectTabbed(lines[i+1:])
-                fn.insert(0, m.group(2))
-                i += _i-1 # skip past footnote
-                self.footnotes.setFootnote(m.group(1), "\n".join(fn))
-            else:
-                newlines.append(lines[i])
-            if len(lines) > i+1:
-                i += 1
-            else:
-                break
-        return newlines
-
-    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 index of last line.
-
-        """
-        items = []
-        blank_line = False # have we encountered a blank line yet?
-        i = 0 # to keep track of where we are
-
-        def detab(line):
-            match = TABBED_RE.match(line)
-            if match:
-               return match.group(4)
-
-        for line in lines:
-            if line.strip(): # Non-blank line
-                detabbed_line = detab(line)
-                if detabbed_line:
-                    items.append(detabbed_line)
-                    i += 1
-                    continue
-                elif not blank_line and not DEF_RE.match(line):
-                    # not tabbed but still part of first par.
-                    items.append(line)
-                    i += 1
-                    continue
-                else:
-                    return items, i+1
-
-            else: # Blank line: _maybe_ we are done.
-                blank_line = True
-                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, i
-
-
-class FootnotePattern(Pattern):
-    """ InlinePattern for footnote markers in a document's body text. """
-
-    def __init__(self, pattern, footnotes):
-        super(FootnotePattern, self).__init__(pattern)
-        self.footnotes = footnotes
-
-    def handleMatch(self, m):
-        id = m.group(2)
-        if id in self.footnotes.footnotes.keys():
-            sup = etree.Element("sup")
-            a = etree.SubElement(sup, "a")
-            sup.set('id', self.footnotes.makeFootnoteRefId(id))
-            a.set('href', '#' + self.footnotes.makeFootnoteId(id))
-            if self.footnotes.md.output_format not in ['html5', 'xhtml5']:
-                a.set('rel', 'footnote') # invalid in HTML5
-            a.set('class', 'footnote-ref')
-            a.text = text_type(self.footnotes.footnotes.index(id) + 1)
-            return sup
-        else:
-            return None
-
-
-class FootnoteTreeprocessor(Treeprocessor):
-    """ Build and append footnote div to end of document. """
-
-    def __init__ (self, footnotes):
-        self.footnotes = footnotes
-
-    def run(self, root):
-        footnotesDiv = self.footnotes.makeFootnotesDiv(root)
-        if footnotesDiv:
-            result = self.footnotes.findFootnotesPlaceholder(root)
-            if result:
-                child, parent, isText = result
-                ind = parent.getchildren().index(child)
-                if isText:
-                    parent.remove(child)
-                    parent.insert(ind, footnotesDiv)
-                else:
-                    parent.insert(ind + 1, footnotesDiv)
-                    child.tail = None
-            else:
-                root.append(footnotesDiv)
-
-class FootnotePostprocessor(Postprocessor):
-    """ Replace placeholders with html entities. """
-    def __init__(self, footnotes):
-        self.footnotes = footnotes
-
-    def run(self, text):
-        text = text.replace(FN_BACKLINK_TEXT, self.footnotes.getConfig("BACKLINK_TEXT"))
-        return text.replace(NBSP_PLACEHOLDER, "&#160;")
-
-def makeExtension(configs=[]):
-    """ Return an instance of the FootnoteExtension """
-    return FootnoteExtension(configs=configs)
-