trustieforge/lib/redcloth3.rb

#                                vim:ts=4:sw=4:
# = RedCloth - Textile and Markdown Hybrid for Ruby
#
# Homepage::  http://whytheluckystiff.net/ruby/redcloth/
# Author::    why the lucky stiff (http://whytheluckystiff.net/)
# Copyright:: (cc) 2004 why the lucky stiff (and his puppet organizations.)
# License::   BSD
#
# (see http://hobix.com/textile/ for a Textile Reference.)
#
# Based on (and also inspired by) both:
#
# PyTextile: http://diveintomark.org/projects/textile/textile.py.txt
# Textism for PHP: http://www.textism.com/tools/textile/
#
#

# = RedCloth
#
# RedCloth is a Ruby library for converting Textile and/or Markdown
# into HTML.  You can use either format, intermingled or separately.
# You can also extend RedCloth to honor your own custom text stylings.
#
# RedCloth users are encouraged to use Textile if they are generating
# HTML and to use Markdown if others will be viewing the plain text.
#
# == What is Textile?
#
# Textile is a simple formatting style for text
# documents, loosely based on some HTML conventions.
#
# == Sample Textile Text
#
#  h2. This is a title
#
#  h3. This is a subhead
#
#  This is a bit of paragraph.
#
#  bq. This is a blockquote.
#
# = Writing Textile
#
# A Textile document consists of paragraphs.  Paragraphs
# can be specially formatted by adding a small instruction
# to the beginning of the paragraph.
#
#  h[n].   Header of size [n].
#  bq.     Blockquote.
#  #       Numeric list.
#  *       Bulleted list.
#
# == Quick Phrase Modifiers
#
# Quick phrase modifiers are also included, to allow formatting
# of small portions of text within a paragraph.
#
#  \_emphasis\_
#  \_\_italicized\_\_
#  \*strong\*
#  \*\*bold\*\*
#  ??citation??
#  -deleted text-
#  +inserted text+
#  ^superscript^
#  ~subscript~
#  @code@
#  %(classname)span%
#
#  ==notextile== (leave text alone)
#
# == Links
#
# To make a hypertext link, put the link text in "quotation 
# marks" followed immediately by a colon and the URL of the link.
# 
# Optional: text in (parentheses) following the link text, 
# but before the closing quotation mark, will become a Title 
# attribute for the link, visible as a tool tip when a cursor is above it.
# 
# Example:
#
#  "This is a link (This is a title) ":http://www.textism.com
# 
# Will become:
# 
#  <a href="http://www.textism.com" title="This is a title">This is a link</a>
#
# == Images
#
# To insert an image, put the URL for the image inside exclamation marks.
#
# Optional: text that immediately follows the URL in (parentheses) will 
# be used as the Alt text for the image. Images on the web should always 
# have descriptive Alt text for the benefit of readers using non-graphical 
# browsers.
#
# Optional: place a colon followed by a URL immediately after the 
# closing ! to make the image into a link.
# 
# Example:
#
#  !http://www.textism.com/common/textist.gif(Textist)!
#
# Will become:
#
#  <img src="http://www.textism.com/common/textist.gif" alt="Textist" />
#
# With a link:
#
#  !/common/textist.gif(Textist)!:http://textism.com
#
# Will become:
#
#  <a href="http://textism.com"><img src="/common/textist.gif" alt="Textist" /></a>
#
# == Defining Acronyms
#
# HTML allows authors to define acronyms via the tag. The definition appears as a 
# tool tip when a cursor hovers over the acronym. A crucial aid to clear writing, 
# this should be used at least once for each acronym in documents where they appear.
#
# To quickly define an acronym in Textile, place the full text in (parentheses) 
# immediately following the acronym.
# 
# Example:
#
#  ACLU(American Civil Liberties Union)
#
# Will become:
#
#  <abbr title="American Civil Liberties Union">ACLU</abbr>
#
# == Adding Tables
#
# In Textile, simple tables can be added by seperating each column by
# a pipe.
#
#     |a|simple|table|row|
#     |And|Another|table|row|
#
# Attributes are defined by style definitions in parentheses.
#
#     table(border:1px solid black).
#     (background:#ddd;color:red). |{}| | | |
#
# == Using RedCloth
# 
# RedCloth is simply an extension of the String class, which can handle
# Textile formatting.  Use it like a String and output HTML with its
# RedCloth#to_html method.
#
#  doc = RedCloth.new "
#
#  h2. Test document
#
#  Just a simple test."
#
#  puts doc.to_html
#
# By default, RedCloth uses both Textile and Markdown formatting, with
# Textile formatting taking precedence.  If you want to turn off Markdown
# formatting, to boost speed and limit the processor:
#
#  class RedCloth::Textile.new( str )

class RedCloth3 < String

  VERSION = '3.0.4'
  DEFAULT_RULES = [:textile, :markdown]

  #
  # Two accessor for setting security restrictions.
  #
  # This is a nice thing if you're using RedCloth for
  # formatting in public places (e.g. Wikis) where you
  # don't want users to abuse HTML for bad things.
  #
  # If +:filter_html+ is set, HTML which wasn't
  # created by the Textile processor will be escaped.
  #
  # If +:filter_styles+ is set, it will also disable
  # the style markup specifier. ('{color: red}')
  #
  attr_accessor :filter_html, :filter_styles

  #
  # Accessor for toggling hard breaks.
  #
  # If +:hard_breaks+ is set, single newlines will
  # be converted to HTML break tags.  This is the
  # default behavior for traditional RedCloth.
  #
  attr_accessor :hard_breaks

  # Accessor for toggling lite mode.
  #
  # In lite mode, block-level rules are ignored.  This means
  # that tables, paragraphs, lists, and such aren't available.
  # Only the inline markup for bold, italics, entities and so on.
  #
  #   r = RedCloth.new( "And then? She *fell*!", [:lite_mode] )
  #   r.to_html
  #   #=> "And then? She <strong>fell</strong>!"
  #
  attr_accessor :lite_mode

  #
  # Accessor for toggling span caps.
  #
  # Textile places `span' tags around capitalized
  # words by default, but this wreaks havoc on Wikis.
  # If +:no_span_caps+ is set, this will be
  # suppressed.
  #
  attr_accessor :no_span_caps

  #
  # Establishes the markup predence.  Available rules include:
  #
  # == Textile Rules
  #
  # The following textile rules can be set individually.  Or add the complete
  # set of rules with the single :textile rule, which supplies the rule set in
  # the following precedence:
  #
  # refs_textile::          Textile references (i.e. [hobix]http://hobix.com/)
  # block_textile_table::   Textile table block structures
  # block_textile_lists::   Textile list structures
  # block_textile_prefix::  Textile blocks with prefixes (i.e. bq., h2., etc.)
  # inline_textile_image::  Textile inline images
  # inline_textile_link::   Textile inline links
  # inline_textile_span::   Textile inline spans
  # glyphs_textile:: Textile entities (such as em-dashes and smart quotes)
  #
  # == Markdown
  #
  # refs_markdown::         Markdown references (for example: [hobix]: http://hobix.com/)
  # block_markdown_setext:: Markdown setext headers
  # block_markdown_atx::    Markdown atx headers
  # block_markdown_rule::   Markdown horizontal rules
  # block_markdown_bq::     Markdown blockquotes
  # block_markdown_lists::  Markdown lists
  # inline_markdown_link::  Markdown links
  attr_accessor :rules

  # Returns a new RedCloth object, based on _string_ and
  # enforcing all the included _restrictions_.
  #
  #   r = RedCloth.new( "h1. A <b>bold</b> man", [:filter_html] )
  #   r.to_html
  #     #=>"<h1>A &lt;b&gt;bold&lt;/b&gt; man</h1>"
  #
  def initialize( string, restrictions = [] )
    restrictions.each { |r| method( "#{ r }=" ).call( true ) }
    super( string )
  end

  #
  # Generates HTML from the Textile contents.
  #
  #   r = RedCloth.new( "And then? She *fell*!" )
  #   r.to_html( true )
  #     #=>"And then? She <strong>fell</strong>!"
  #
  def to_html( *rules )
    rules = DEFAULT_RULES if rules.empty?
    # make our working copy
    text = self.dup

    @urlrefs = {}
    @shelf = []
    textile_rules = [:block_textile_table, :block_textile_lists,
                     :block_textile_prefix, :inline_textile_image, :inline_textile_link,
                     :inline_textile_code, :inline_textile_span, :glyphs_textile]
    markdown_rules = [:refs_markdown, :block_markdown_setext, :block_markdown_atx, :block_markdown_rule,
                      :block_markdown_bq, :block_markdown_lists,
                      :inline_markdown_reflink, :inline_markdown_link]
    @rules = rules.collect do |rule|
      case rule
        when :markdown
          markdown_rules
        when :textile
          textile_rules
        else
          rule
      end
    end.flatten

    # standard clean up
    incoming_entities text
    clean_white_space text

    # start processor
    @pre_list = []
    rip_offtags text
    no_textile text
    escape_html_tags text
    # need to do this before #hard_break and #blocks
    block_textile_quotes text unless @lite_mode
    hard_break text
    unless @lite_mode
      refs text
      blocks text
    end
    inline text
    smooth_offtags text

    retrieve text

    text.gsub!( /<\/?notextile>/, '' )
    text.gsub!( /x%x%/, '&#38;' )
    clean_html text if filter_html
    text.strip!
    text

  end

  #######
  private
  #######
  #
  # Mapping of 8-bit ASCII codes to HTML numerical entity equivalents.
  # (from PyTextile)
  #
  TEXTILE_TAGS =

      [[128, 8364], [129, 0], [130, 8218], [131, 402], [132, 8222], [133, 8230],
       [134, 8224], [135, 8225], [136, 710], [137, 8240], [138, 352], [139, 8249],
       [140, 338], [141, 0], [142, 0], [143, 0], [144, 0], [145, 8216], [146, 8217],
       [147, 8220], [148, 8221], [149, 8226], [150, 8211], [151, 8212], [152, 732],
       [153, 8482], [154, 353], [155, 8250], [156, 339], [157, 0], [158, 0], [159, 376]].

          collect! do |a, b|
        [a.chr, ( b.zero? and "" or "&#{ b };" )]
      end

  #
  # Regular expressions to convert to HTML.
  #
  A_HLGN = /(?:(?:<>|<|>|\=|[()]+)+)/
  A_VLGN = /[\-^~]/
  C_CLAS = '(?:\([^")]+\))'
  C_LNGE = '(?:\[[^"\[\]]+\])'
  C_STYL = '(?:\{[^"}]+\})'
  S_CSPN = '(?:\\\\\d+)'
  S_RSPN = '(?:/\d+)'
  A = "(?:#{A_HLGN}?#{A_VLGN}?|#{A_VLGN}?#{A_HLGN}?)"
  S = "(?:#{S_CSPN}?#{S_RSPN}|#{S_RSPN}?#{S_CSPN}?)"
  C = "(?:#{C_CLAS}?#{C_STYL}?#{C_LNGE}?|#{C_STYL}?#{C_LNGE}?#{C_CLAS}?|#{C_LNGE}?#{C_STYL}?#{C_CLAS}?)"
  # PUNCT = Regexp::quote( '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~' )
  PUNCT = Regexp::quote( '!"#$%&\'*+,-./:;=?@\\^_`|~' )
  PUNCT_NOQ = Regexp::quote( '!"#$&\',./:;=?@\\`|' )
  PUNCT_Q = Regexp::quote( '*-_+^~%' )
  HYPERLINK = '(\S+?)([^\w\s/;=\?]*?)(?=\s|<|$)'

  # Text markup tags, don't conflict with block tags
  SIMPLE_HTML_TAGS = [
      'tt', 'b', 'i', 'big', 'small', 'em', 'strong', 'dfn', 'code',
      'samp', 'kbd', 'var', 'cite', 'abbr', 'acronym', 'a', 'img', 'br',
      'br', 'map', 'q', 'sub', 'sup', 'span', 'bdo'
  ]

  QTAGS = [
      ['**', 'b', :limit],
      ['*', 'strong', :limit],
      ['??', 'cite', :limit],
      ['-', 'del', :limit],
      ['__', 'i', :limit],
      ['_', 'em', :limit],
      ['%', 'span', :limit],
      ['+', 'ins', :limit],
      ['^', 'sup', :limit],
      ['~', 'sub', :limit]
  ]
  QTAGS_JOIN = QTAGS.map {|rc, ht, rtype| Regexp::quote rc}.join('|')

  QTAGS.collect! do |rc, ht, rtype|
    rcq = Regexp::quote rc
    re =
        case rtype
          when :limit
            /(^|[>\s\(])          # sta
                (?!\-\-)
                (#{QTAGS_JOIN}|)      # oqs
                (#{rcq})              # qtag
                (\w|[^\s].*?[^\s])    # content
                (?!\-\-)
                #{rcq}
                (#{QTAGS_JOIN}|)      # oqa
                (?=[[:punct:]]|<|\s|\)|$)/x
          else
            /(#{rcq})
                (#{C})
                (?::(\S+))?
                (\w|[^\s\-].*?[^\s\-])
                #{rcq}/xm
        end
    [rc, ht, re, rtype]
  end

  # Elements to handle
  GLYPHS = [
      #   [ /([^\s\[{(>])?\'([dmst]\b|ll\b|ve\b|\s|:|$)/, '\1&#8217;\2' ], # single closing
      #   [ /([^\s\[{(>#{PUNCT_Q}][#{PUNCT_Q}]*)\'/, '\1&#8217;' ], # single closing
      #   [ /\'(?=[#{PUNCT_Q}]*(s\b|[\s#{PUNCT_NOQ}]))/, '&#8217;' ], # single closing
      #   [ /\'/, '&#8216;' ], # single opening
      #   [ /</, '&lt;' ], # less-than
      #   [ />/, '&gt;' ], # greater-than
      #   [ /([^\s\[{(])?"(\s|:|$)/, '\1&#8221;\2' ], # double closing
      #   [ /([^\s\[{(>#{PUNCT_Q}][#{PUNCT_Q}]*)"/, '\1&#8221;' ], # double closing
      #   [ /"(?=[#{PUNCT_Q}]*[\s#{PUNCT_NOQ}])/, '&#8221;' ], # double closing
      #   [ /"/, '&#8220;' ], # double opening
      #   [ /\b( )?\.{3}/, '\1&#8230;' ], # ellipsis
      #   [ /\b([A-Z][A-Z0-9]{2,})\b(?:[(]([^)]*)[)])/, '<acronym title="\2">\1</acronym>' ], # 3+ uppercase acronym
      #   [ /(^|[^"][>\s])([A-Z][A-Z0-9 ]+[A-Z0-9])([^<A-Za-z0-9]|$)/, '\1<span class="caps">\2</span>\3', :no_span_caps ], # 3+ uppercase caps
      #   [ /(\.\s)?\s?--\s?/, '\1&#8212;' ], # em dash
      #   [ /\s->\s/, ' &rarr; ' ], # right arrow
      #   [ /\s-\s/, ' &#8211; ' ], # en dash
      #   [ /(\d+) ?x ?(\d+)/, '\1&#215;\2' ], # dimension sign
      #   [ /\b ?[(\[]TM[\])]/i, '&#8482;' ], # trademark
      #   [ /\b ?[(\[]R[\])]/i, '&#174;' ], # registered
      #   [ /\b ?[(\[]C[\])]/i, '&#169;' ] # copyright
  ]

  H_ALGN_VALS = {
      '<' => 'left',
      '=' => 'center',
      '>' => 'right',
      '<>' => 'justify'
  }

  V_ALGN_VALS = {
      '^' => 'top',
      '-' => 'middle',
      '~' => 'bottom'
  }

  #
  # Flexible HTML escaping
  #
  def htmlesc( str, mode=:Quotes )
    if str
      str.gsub!( '&', '&amp;' )
      str.gsub!( '"', '&quot;' ) if mode != :NoQuotes
      str.gsub!( "'", '&#039;' ) if mode == :Quotes
      str.gsub!( '<', '&lt;')
      str.gsub!( '>', '&gt;')
    end
    str
  end

  # Search and replace for Textile glyphs (quotes, dashes, other symbols)
  def pgl( text )
    #GLYPHS.each do |re, resub, tog|
    #    next if tog and method( tog ).call
    #    text.gsub! re, resub
    #end
    text.gsub!(/\b([A-Z][A-Z0-9]{1,})\b(?:[(]([^)]*)[)])/) do |m|
      "<abbr title=\"#{htmlesc $2}\">#{$1}</abbr>"
    end
  end

  # Parses Textile attribute lists and builds an HTML attribute string
  def pba( text_in, element = "" )

    return '' unless text_in

    style = []
    text = text_in.dup
    if element == 'td'
      colspan = $1 if text =~ /\\(\d+)/
      rowspan = $1 if text =~ /\/(\d+)/
      style << "vertical-align:#{ v_align( $& ) };" if text =~ A_VLGN
    end

    if text.sub!( /\{([^"}]*)\}/, '' ) && !filter_styles
      sanitized = sanitize_styles($1)
      style << "#{ sanitized };" unless sanitized.blank?
    end

    lang = $1 if
        text.sub!( /\[([^)]+?)\]/, '' )

    cls = $1 if
        text.sub!( /\(([^()]+?)\)/, '' )

    style << "padding-left:#{ $1.length }em;" if
        text.sub!( /([(]+)/, '' )

    style << "padding-right:#{ $1.length }em;" if text.sub!( /([)]+)/, '' )

    style << "text-align:#{ h_align( $& ) };" if text =~ A_HLGN

    cls, id = $1, $2 if cls =~ /^(.*?)#(.*)$/

    atts = ''
    atts << " style=\"#{ style.join }\"" unless style.empty?
    atts << " class=\"#{ cls }\"" unless cls.to_s.empty?
    atts << " lang=\"#{ lang }\"" if lang
    atts << " id=\"#{ id }\"" if id
    atts << " colspan=\"#{ colspan }\"" if colspan
    atts << " rowspan=\"#{ rowspan }\"" if rowspan

    atts
  end

  STYLES_RE = /^(color|width|height|border|background|padding|margin|font|text|float)(-[a-z]+)*:\s*((\d+%?|\d+px|\d+(\.\d+)?em|#[0-9a-f]+|[a-z]+)\s*)+$/i

  def sanitize_styles(str)
    styles = str.split(";").map(&:strip)
    styles.reject! do |style|
      !style.match(STYLES_RE)
    end
    styles.join(";")
  end

  TABLE_RE = /^(?:table(_?#{S}#{A}#{C})\. ?\n)?^(#{A}#{C}\.? ?\|.*?\|)(\n\n|\Z)/m

  # Parses a Textile table block, building HTML from the result.
  def block_textile_table( text )
    text.gsub!( TABLE_RE ) do |matches|

      tatts, fullrow = $~[1..2]
      tatts = pba( tatts, 'table' )
      tatts = shelve( tatts ) if tatts
      rows = []
      fullrow.gsub!(/([^|])\n/, "\\1<br />")
      fullrow.each_line do |row|
        ratts, row = pba( $1, 'tr' ), $2 if row =~ /^(#{A}#{C}\. )(.*)/m
        cells = []
        row.split( /(\|)(?![^\[\|]*\]\])/ )[1..-2].each do |cell|
          next if cell == '|'
          ctyp = 'd'
          ctyp = 'h' if cell =~ /^_/

          catts = ''
          catts, cell = pba( $1, 'td' ), $2 if cell =~ /^(_?#{S}#{A}#{C}\. ?)(.*)/

          catts = shelve( catts ) if catts
          cells << "\t\t\t<t#{ ctyp }#{ catts }>#{ cell }</t#{ ctyp }>"
        end
        ratts = shelve( ratts ) if ratts
        rows << "\t\t<tr#{ ratts }>\n#{ cells.join( "\n" ) }\n\t\t</tr>"
      end
      "\t<table#{ tatts }>\n#{ rows.join( "\n" ) }\n\t</table>\n\n"
    end
  end

  LISTS_RE = /^([#*]+?#{C} .*?)$(?![^#*])/m
  LISTS_CONTENT_RE = /^([#*]+)(#{A}#{C}) (.*)$/m

  # Parses Textile lists and generates HTML
  def block_textile_lists( text )
    text.gsub!( LISTS_RE ) do |match|
      lines = match.split( /\n/ )
      last_line = -1
      depth = []
      lines.each_with_index do |line, line_id|
        if line =~ LISTS_CONTENT_RE
          tl,atts,content = $~[1..3]
          if depth.last
            if depth.last.length > tl.length
              (depth.length - 1).downto(0) do |i|
                break if depth[i].length == tl.length
                lines[line_id - 1] << "</li>\n\t</#{ lT( depth[i] ) }l>\n\t"
                depth.pop
              end
            end
            if depth.last and depth.last.length == tl.length
              lines[line_id - 1] << '</li>'
            end
          end
          unless depth.last == tl
            depth << tl
            atts = pba( atts )
            atts = shelve( atts ) if atts
            lines[line_id] = "\t<#{ lT(tl) }l#{ atts }>\n\t<li>#{ content }"
          else
            lines[line_id] = "\t\t<li>#{ content }"
          end
          last_line = line_id

        else
          last_line = line_id
        end
        if line_id - last_line > 1 or line_id == lines.length - 1
          while v = depth.pop
            lines[last_line] << "</li>\n\t</#{ lT( v ) }l>"
          end
        end
      end
      lines.join( "\n" )
    end
  end

  QUOTES_RE = /(^>+([^\n]*?)(\n|$))+/m
  QUOTES_CONTENT_RE = /^([> ]+)(.*)$/m

  def block_textile_quotes( text )
    text.gsub!( QUOTES_RE ) do |match|
      lines = match.split( /\n/ )
      quotes = ''
      indent = 0
      lines.each do |line|
        line =~ QUOTES_CONTENT_RE
        bq,content = $1, $2
        l = bq.count('>')
        if l != indent
          quotes << ("\n\n" + (l>indent ? '<blockquote>' * (l-indent) : '</blockquote>' * (indent-l)) + "\n\n")
          indent = l
        end
        quotes << (content + "\n")
      end
      quotes << ("\n" + '</blockquote>' * indent + "\n\n")
      quotes
    end
  end

  CODE_RE = /(\W)
        @
        (?:\|(\w+?)\|)?
        (.+?)
        @
        (?=\W)/x

  def inline_textile_code( text )
    text.gsub!( CODE_RE ) do |m|
      before,lang,code,after = $~[1..4]
      lang = " lang=\"#{ lang }\"" if lang
      rip_offtags( "#{ before }<code#{ lang }>#{ code }</code>#{ after }", false )
    end
  end

  def lT( text )
    text =~ /\#$/ ? 'o' : 'u'
  end

  def hard_break( text )
    text.gsub!( /(.)\n(?!\Z| *([#*=]+(\s|$)|[{|]))/, "\\1<br />" ) if hard_breaks
  end

  BLOCKS_GROUP_RE = /\n{2,}(?! )/m

  def blocks( text, deep_code = false )
    text.replace( text.split( BLOCKS_GROUP_RE ).collect do |blk|
      plain = blk !~ /\A[#*> ]/

      # skip blocks that are complex HTML
      if blk =~ /^<\/?(\w+).*>/ and not SIMPLE_HTML_TAGS.include? $1
        blk
      else
        # search for indentation levels
        blk.strip!
        if blk.empty?
          blk
        else
          code_blk = nil
          blk.gsub!( /((?:\n(?:\n^ +[^\n]*)+)+)/m ) do |iblk|
            flush_left iblk
            blocks iblk, plain
            iblk.gsub( /^(\S)/, "\t\\1" )
            if plain
              code_blk = iblk; ""
            else
              iblk
            end
          end

          block_applied = 0
          @rules.each do |rule_name|
            block_applied += 1 if ( rule_name.to_s.match /^block_/ and method( rule_name ).call( blk ) )
          end
          if block_applied.zero?
            if deep_code
              blk = "\t<pre><code>#{ blk }</code></pre>"
            else
              blk = "\t<p>#{ blk }</p>"
            end
          end
          # hard_break blk
          blk + "\n#{ code_blk }"
        end
      end

    end.join( "\n\n" ) )
  end

  def textile_bq( tag, atts, cite, content )
    cite, cite_title = check_refs( cite )
    cite = " cite=\"#{ cite }\"" if cite
    atts = shelve( atts ) if atts
    "\t<blockquote#{ cite }>\n\t\t<p#{ atts }>#{ content }</p>\n\t</blockquote>"
  end

  def textile_p( tag, atts, cite, content )
    atts = shelve( atts ) if atts
    "\t<#{ tag }#{ atts }>#{ content }</#{ tag }>"
  end

  alias textile_h1 textile_p
  alias textile_h2 textile_p
  alias textile_h3 textile_p
  alias textile_h4 textile_p
  alias textile_h5 textile_p
  alias textile_h6 textile_p

  def textile_fn_( tag, num, atts, cite, content )
    atts << " id=\"fn#{ num }\" class=\"footnote\""
    content = "<sup>#{ num }</sup> #{ content }"
    atts = shelve( atts ) if atts
    "\t<p#{ atts }>#{ content }</p>"
  end

  BLOCK_RE = /^(([a-z]+)(\d*))(#{A}#{C})\.(?::(\S+))? (.*)$/m

  def block_textile_prefix( text )
    if text =~ BLOCK_RE
      tag,tagpre,num,atts,cite,content = $~[1..6]
      atts = pba( atts )

      # pass to prefix handler
      replacement = nil
      if respond_to? "textile_#{ tag }", true
        replacement = method( "textile_#{ tag }" ).call( tag, atts, cite, content )
      elsif respond_to? "textile_#{ tagpre }_", true
        replacement = method( "textile_#{ tagpre }_" ).call( tagpre, num, atts, cite, content )
      end
      text.gsub!( $& ) { replacement } if replacement
    end
  end

  SETEXT_RE = /\A(.+?)\n([=-])[=-]* *$/m
  def block_markdown_setext( text )
    if text =~ SETEXT_RE
      tag = if $2 == "="; "h1"; else; "h2"; end
      blk, cont = "<#{ tag }>#{ $1 }</#{ tag }>", $'
      blocks cont
      text.replace( blk + cont )
    end
  end

  ATX_RE = /\A(\#{1,6})  # $1 = string of #'s
              [ ]*
              (.+?)       # $2 = Header text
              [ ]*
              \#*         # optional closing #'s (not counted)
              $/x
  def block_markdown_atx( text )
    if text =~ ATX_RE
      tag = "h#{ $1.length }"
      blk, cont = "<#{ tag }>#{ $2 }</#{ tag }>\n\n", $'
      blocks cont
      text.replace( blk + cont )
    end
  end

  MARKDOWN_BQ_RE = /\A(^ *> ?.+$(.+\n)*\n*)+/m

  def block_markdown_bq( text )
    text.gsub!( MARKDOWN_BQ_RE ) do |blk|
      blk.gsub!( /^ *> ?/, '' )
      flush_left blk
      blocks blk
      blk.gsub!( /^(\S)/, "\t\\1" )
      "<blockquote>\n#{ blk }\n</blockquote>\n\n"
    end
  end

  MARKDOWN_RULE_RE = /^(#{
  ['*', '-', '_'].collect { |ch| ' ?(' + Regexp::quote( ch ) + ' ?){3,}' }.join( '|' )
  })$/

  def block_markdown_rule( text )
    text.gsub!( MARKDOWN_RULE_RE ) do |blk|
      "<hr />"
    end
  end

  # XXX TODO XXX
  def block_markdown_lists( text )
  end

  def inline_textile_span( text )
    QTAGS.each do |qtag_rc, ht, qtag_re, rtype|
      text.gsub!( qtag_re ) do |m|

        case rtype
          when :limit
            sta,oqs,qtag,content,oqa = $~[1..6]
            atts = nil
            if content =~ /^(#{C})(.+)$/
              atts, content = $~[1..2]
            end
          else
            qtag,atts,cite,content = $~[1..4]
            sta = ''
        end
        atts = pba( atts )
        atts = shelve( atts ) if atts

        "#{ sta }#{ oqs }<#{ ht }#{ atts }>#{ content }</#{ ht }>#{ oqa }"

      end
    end
  end

  LINK_RE = /
            (
            ([\s\[{(]|[#{PUNCT}])?     # $pre
            "                          # start
            (#{C})                     # $atts
            ([^"\n]+?)                 # $text
            \s?
            (?:\(([^)]+?)\)(?="))?     # $title
            ":
            (                          # $url
            (\/|[a-zA-Z]+:\/\/|www\.|mailto:)  # $proto
            [[:alnum:]_\/]\S+?
            )               
            (\/)?                      # $slash
            ([^[:alnum:]_\=\/;\(\)]*?)         # $post
            )
            (?=<|\s|$)
        /x
  #"
  def inline_textile_link( text )
    text.gsub!( LINK_RE ) do |m|
      all,pre,atts,text,title,url,proto,slash,post = $~[1..9]
      if text.include?('<br />')
        all
      else
        url, url_title = check_refs( url )
        title ||= url_title

        # Idea below : an URL with unbalanced parethesis and
        # ending by ')' is put into external parenthesis
        if ( url[-1]==?) and ((url.count("(") - url.count(")")) < 0 ) )
          url=url[0..-2] # discard closing parenth from url
          post = ")"+post # add closing parenth to post
        end
        atts = pba( atts )
        atts = " href=\"#{ htmlesc url }#{ slash }\"#{ atts }"
        atts << " title=\"#{ htmlesc title }\"" if title
        atts = shelve( atts ) if atts

        external = (url =~ /^https?:\/\//) ? ' class="external"' : ''

        "#{ pre }<a#{ atts }#{ external }>#{ text }</a>#{ post }"
      end
    end
  end

  MARKDOWN_REFLINK_RE = /
            \[([^\[\]]+)\]      # $text
            [ ]?                # opt. space
            (?:\n[ ]*)?         # one optional newline followed by spaces
            \[(.*?)\]           # $id
        /x

  def inline_markdown_reflink( text )
    text.gsub!( MARKDOWN_REFLINK_RE ) do |m|
      text, id = $~[1..2]

      if id.empty?
        url, title = check_refs( text )
      else
        url, title = check_refs( id )
      end

      atts = " href=\"#{ url }\""
      atts << " title=\"#{ title }\"" if title
      atts = shelve( atts )

      "<a#{ atts }>#{ text }</a>"
    end
  end

  MARKDOWN_LINK_RE = /
            \[([^\[\]]+)\]      # $text
            \(                  # open paren
            [ \t]*              # opt space
            <?(.+?)>?           # $href
            [ \t]*              # opt space
            (?:                 # whole title
            (['"])              # $quote
            (.*?)               # $title
            \3                  # matching quote
            )?                  # title is optional
            \)
        /x

  def inline_markdown_link( text )
    text.gsub!( MARKDOWN_LINK_RE ) do |m|
      text, url, quote, title = $~[1..4]

      atts = " href=\"#{ url }\""
      atts << " title=\"#{ title }\"" if title
      atts = shelve( atts )

      "<a#{ atts }>#{ text }</a>"
    end
  end

  TEXTILE_REFS_RE =  /(^ *)\[([^\[\n]+?)\](#{HYPERLINK})(?=\s|$)/
  MARKDOWN_REFS_RE = /(^ *)\[([^\n]+?)\]:\s+<?(#{HYPERLINK})>?(?:\s+"((?:[^"]|\\")+)")?(?=\s|$)/m

  def refs( text )
    @rules.each do |rule_name|
      method( rule_name ).call( text ) if rule_name.to_s.match /^refs_/
    end
  end

  def refs_textile( text )
    text.gsub!( TEXTILE_REFS_RE ) do |m|
      flag, url = $~[2..3]
      @urlrefs[flag.downcase] = [url, nil]
      nil
    end
  end

  def refs_markdown( text )
    text.gsub!( MARKDOWN_REFS_RE ) do |m|
      flag, url = $~[2..3]
      title = $~[6]
      @urlrefs[flag.downcase] = [url, title]
      nil
    end
  end

  def check_refs( text )
    ret = @urlrefs[text.downcase] if text
    ret || [text, nil]
  end

  IMAGE_RE = /
            (>|\s|^)           # start of line?
            \!                   # opening
            (\<|\=|\>)?          # optional alignment atts
            (#{C})               # optional style,class atts
            (?:\. )?             # optional dot-space
            ([^\s(!]+?)          # presume this is the src
            \s?                  # optional space
            (?:\(((?:[^\(\)]|\([^\)]+\))+?)\))?   # optional title
            \!                   # closing
            (?::#{ HYPERLINK })? # optional href
        /x

  def inline_textile_image( text )
    text.gsub!( IMAGE_RE )  do |m|
      stln,algn,atts,url,title,href,href_a1,href_a2 = $~[1..8]
      htmlesc title
      atts = pba( atts )
      atts = " src=\"#{ htmlesc url.dup }\"#{ atts }"
      atts << " title=\"#{ title }\"" if title
      atts << " alt=\"#{ title }\""
      # size = @getimagesize($url);
      # if($size) $atts.= " $size[3]";

      href, alt_title = check_refs( href ) if href
      url, url_title = check_refs( url )

      out = ''
      out << "<a#{ shelve( " href=\"#{ href }\"" ) }>" if href
      out << "<img#{ shelve( atts ) } />"
      out << "</a>#{ href_a1 }#{ href_a2 }" if href

      if algn
        algn = h_align( algn )
        if stln == "<p>"
          out = "<p style=\"float:#{ algn }\">#{ out }"
        else
          out = "#{ stln }<div style=\"float:#{ algn }\">#{ out }</div>"
        end
      else
        out = stln + out
      end

      out
    end
  end

  def shelve( val )
    @shelf << val
    " :redsh##{ @shelf.length }:"
  end

  def retrieve( text )
    @shelf.each_with_index do |r, i|
      text.gsub!( " :redsh##{ i + 1 }:", r )
    end
  end

  def incoming_entities( text )
    ## turn any incoming ampersands into a dummy character for now.
    ## This uses a negative lookahead for alphanumerics followed by a semicolon,
    ## implying an incoming html entity, to be skipped

    text.gsub!( /&(?![#a-z0-9]+;)/i, "x%x%" )
  end

  def no_textile( text )
    text.gsub!( /(^|\s)==([^=]+.*?)==(\s|$)?/,
                '\1<notextile>\2</notextile>\3' )
    text.gsub!( /^ *==([^=]+.*?)==/m,
                '\1<notextile>\2</notextile>\3' )
  end

  def clean_white_space( text )
    # normalize line breaks
    text.gsub!( /\r\n/, "\n" )
    text.gsub!( /\r/, "\n" )
    text.gsub!( /\t/, '    ' )
    text.gsub!( /^ +$/, '' )
    text.gsub!( /\n{3,}/, "\n\n" )
    text.gsub!( /"$/, "\" " )

    # if entire document is indented, flush
    # to the left side
    flush_left text
  end

  def flush_left( text )
    indt = 0
    if text =~ /^ /
      while text !~ /^ {#{indt}}\S/
        indt += 1
      end unless text.empty?
      if indt.nonzero?
        text.gsub!( /^ {#{indt}}/, '' )
      end
    end
  end

  def footnote_ref( text )
    text.gsub!( /\b\[([0-9]+?)\](\s)?/,
                '<sup><a href="#fn\1">\1</a></sup>\2' )
  end

  OFFTAGS = /(code|pre|kbd|notextile)/
  OFFTAG_MATCH = /(?:(<\/#{ OFFTAGS }>)|(<#{ OFFTAGS }[^>]*>))(.*?)(?=<\/?#{ OFFTAGS }\W|\Z)/mi
  OFFTAG_OPEN = /<#{ OFFTAGS }/
  OFFTAG_CLOSE = /<\/?#{ OFFTAGS }/
  HASTAG_MATCH = /(<\/?\w[^\n]*?>)/m
  ALLTAG_MATCH = /(<\/?\w[^\n]*?>)|.*?(?=<\/?\w[^\n]*?>|$)/m

  def glyphs_textile( text, level = 0 )
    if text !~ HASTAG_MATCH
      pgl text
      footnote_ref text
    else
      codepre = 0
      text.gsub!( ALLTAG_MATCH ) do |line|
        ## matches are off if we're between <code>, <pre> etc.
        if $1
          if line =~ OFFTAG_OPEN
            codepre += 1
          elsif line =~ OFFTAG_CLOSE
            codepre -= 1
            codepre = 0 if codepre < 0
          end
        elsif codepre.zero?
          glyphs_textile( line, level + 1 )
        else
          htmlesc( line, :NoQuotes )
        end
        # p [level, codepre, line]

        line
      end
    end
  end

  def rip_offtags( text, escape_aftertag=true, escape_line=true )
    if text =~ /<.*>/
      ## strip and encode <pre> content
      codepre, used_offtags = 0, {}
      text.gsub!( OFFTAG_MATCH ) do |line|
        if $3
          first, offtag, aftertag = $3, $4, $5
          codepre += 1
          used_offtags[offtag] = true
          if codepre - used_offtags.length > 0
            htmlesc( line, :NoQuotes ) if escape_line
            @pre_list.last << line
            line = ""
          else
            ### htmlesc is disabled between CODE tags which will be parsed with highlighter
            ### Regexp in formatter.rb is : /<code\s+class="(\w+)">\s?(.+)/m
            ### NB: some changes were made not to use $N variables, because we use "match"
            ###   and it breaks following lines
            htmlesc( aftertag, :NoQuotes ) if aftertag && escape_aftertag && !first.match(/<code\s+class="(\w+)">/)
            line = "<redpre##{ @pre_list.length }>"
            first.match(/<#{ OFFTAGS }([^>]*)>/)
            tag = $1
            $2.to_s.match(/(class\=("[^"]+"|'[^']+'))/i)
            tag << " #{$1}" if $1
            @pre_list << "<#{ tag }>#{ aftertag }"
          end
        elsif $1 and codepre > 0
          if codepre - used_offtags.length > 0
            htmlesc( line, :NoQuotes ) if escape_line
            @pre_list.last << line
            line = ""
          end
          codepre -= 1 unless codepre.zero?
          used_offtags = {} if codepre.zero?
        end
        line
      end
    end
    text
  end

  def smooth_offtags( text )
    unless @pre_list.empty?
      ## replace <pre> content
      text.gsub!( /<redpre#(\d+)>/ ) { @pre_list[$1.to_i] }
    end
  end

  def inline( text )
    [/^inline_/, /^glyphs_/].each do |meth_re|
      @rules.each do |rule_name|
        method( rule_name ).call( text ) if rule_name.to_s.match( meth_re )
      end
    end
  end

  def h_align( text )
    H_ALGN_VALS[text]
  end

  def v_align( text )
    V_ALGN_VALS[text]
  end

  def textile_popup_help( name, windowW, windowH )
    ' <a target="_blank" href="http://hobix.com/textile/#' + helpvar + '" onclick="window.open(this.href, \'popupwindow\', \'width=' + windowW + ',height=' + windowH + ',scrollbars,resizable\'); return false;">' + name + '</a><br />'
  end

  # HTML cleansing stuff
  BASIC_TAGS = {
      'a' => ['href', 'title'],
      'img' => ['src', 'alt', 'title'],
      'br' => [],
      'i' => nil,
      'u' => nil,
      'b' => nil,
      'pre' => nil,
      'kbd' => nil,
      'code' => ['lang'],
      'cite' => nil,
      'strong' => nil,
      'em' => nil,
      'ins' => nil,
      'sup' => nil,
      'sub' => nil,
      'del' => nil,
      'table' => nil,
      'tr' => nil,
      'td' => ['colspan', 'rowspan'],
      'th' => nil,
      'ol' => nil,
      'ul' => nil,
      'li' => nil,
      'p' => nil,
      'h1' => nil,
      'h2' => nil,
      'h3' => nil,
      'h4' => nil,
      'h5' => nil,
      'h6' => nil,
      'blockquote' => ['cite']
  }

  def clean_html( text, tags = BASIC_TAGS )
    text.gsub!( /<!\[CDATA\[/, '' )
    text.gsub!( /<(\/*)(\w+)([^>]*)>/ ) do
      raw = $~
      tag = raw[2].downcase
      if tags.has_key? tag
        pcs = [tag]
        tags[tag].each do |prop|
          ['"', "'", ''].each do |q|
            q2 = ( q != '' ? q : '\s' )
            if raw[3] =~ /#{prop}\s*=\s*#{q}([^#{q2}]+)#{q}/i
              attrv = $1
              next if prop == 'src' and attrv =~ %r{^(?!http)\w+:}
              pcs << "#{prop}=\"#{$1.gsub('"', '\\"')}\""
              break
            end
          end
        end if tags[tag]
        "<#{raw[1]}#{pcs.join " "}>"
      else
        " "
      end
    end
  end

  ALLOWED_TAGS = %w(redpre pre code notextile)

  def escape_html_tags(text)
    text.gsub!(%r{<(\/?([!\w]+)[^<>\n]*)(>?)}) {|m| ALLOWED_TAGS.include?($2) ? "<#{$1}#{$3}" : "&lt;#{$1}#{'&gt;' unless $3.blank?}" }
  end
end