# heavily based off # https://github.com/vmg/redcarpet/blob/master/ext/redcarpet/html_smartypants.c # and # https://github.com/jmcnevin/rubypants/blob/master/lib/rubypants/core.rb # 99% of the code here is by Jeremy McNevin # # This Source File is available under BSD/MIT license as well as standard GPL # class HtmlPrettify < String def self.render(html) new(html).to_html end # Create a new RubyPants instance with the text in +string+. # # Allowed elements in the options array: # # 0 :: do nothing # 1 :: enable all, using only em-dash shortcuts # 2 :: enable all, using old school en- and em-dash shortcuts (*default*) # 3 :: enable all, using inverted old school en and em-dash shortcuts # -1 :: stupefy (translate HTML entities to their ASCII-counterparts) # # If you don't like any of these defaults, you can pass symbols to change # RubyPants' behavior: # # :quotes :: quotes # :backticks :: backtick quotes (``double'' only) # :allbackticks :: backtick quotes (``double'' and `single') # :dashes :: dashes # :oldschool :: old school dashes # :inverted :: inverted old school dashes # :ellipses :: ellipses # :convertquotes :: convert " entities to # " # :stupefy :: translate RubyPants HTML entities # to their ASCII counterparts. # # In addition, you can customize the HTML entities that will be injected by # passing in a hash for the final argument. The defaults for these entities # are as follows: # # :single_left_quote :: # :double_left_quote :: # :single_right_quote :: # :double_right_quote :: # :em_dash :: # :en_dash :: # :ellipsis :: # :html_quote :: " # def initialize(string, options=[2], entities = {}) super string @options = [*options] @entities = default_entities.update(entities) end # Apply SmartyPants transformations. def to_html do_quotes = do_backticks = do_dashes = do_ellipses = nil if @options.include?(0) # Do nothing. return self elsif @options.include?(1) # Do everything, turn all options on. do_quotes = do_backticks = do_ellipses = true do_dashes = :normal elsif @options.include?(2) # Do everything, turn all options on, use old school dash shorthand. do_quotes = do_backticks = do_ellipses = true do_dashes = :oldschool elsif @options.include?(3) # Do everything, turn all options on, use inverted old school # dash shorthand. do_quotes = do_backticks = do_ellipses = true do_dashes = :inverted elsif @options.include?(-1) do_stupefy = true else do_quotes = @options.include?(:quotes) do_backticks = @options.include?(:backticks) do_backticks = :both if @options.include?(:allbackticks) do_dashes = :normal if @options.include?(:dashes) do_dashes = :oldschool if @options.include?(:oldschool) do_dashes = :inverted if @options.include?(:inverted) do_ellipses = @options.include?(:ellipses) do_stupefy = @options.include?(:stupefy) end # Parse the HTML tokens = tokenize # Keep track of when we're inside
 or  tags.
    in_pre = false

    # Here is the result stored in.
    result = ""

    # This is a cheat, used to get some context for one-character
    # tokens that consist of just a quote char. What we do is remember
    # the last character of the previous text token, to use as context
    # to curl single- character quote tokens correctly.
    prev_token_last_char = nil

    tokens.each do |token|
      if token.first == :tag
        result << token[1]
        if token[1] =~ %r!<(/?)(?:pre|code|kbd|script|math)[\s>]!
          in_pre = ($1 != "/")  # Opening or closing tag?
        end
      else
        t = token[1]

        # Remember last char of this token before processing.
        last_char = t[-1].chr

        unless in_pre

          t.gsub!("'", "'")
          t.gsub!(""", '"')

          if do_dashes
            t = educate_dashes t            if do_dashes == :normal
            t = educate_dashes_oldschool t  if do_dashes == :oldschool
            t = educate_dashes_inverted t   if do_dashes == :inverted
          end

          t = educate_ellipses t  if do_ellipses

          t = educate_fractions t

          # Note: backticks need to be processed before quotes.
          if do_backticks
            t = educate_backticks t
            t = educate_single_backticks t  if do_backticks == :both
          end

          if do_quotes
            if t == "'"
              # Special case: single-character ' token
              if prev_token_last_char =~ /\S/
                t = entity(:single_right_quote)
              else
                t = entity(:single_left_quote)
              end
            elsif t == '"'
              # Special case: single-character " token
              if prev_token_last_char =~ /\S/
                t = entity(:double_right_quote)
              else
                t = entity(:double_left_quote)
              end
            else
              # Normal case:
              t = educate_quotes t
            end
          end

          t = stupefy_entities t  if do_stupefy
        end

        prev_token_last_char = last_char
        result << t
      end
    end

    # Done
    result
  end

  protected


  # The string, with each instance of "--" translated to an
  # em-dash HTML entity.
  #
  def educate_dashes(str)
    str.
      gsub(/--/, entity(:em_dash))
  end

  # The string, with each instance of "--" translated to an
  # en-dash HTML entity, and each "---" translated to an
  # em-dash HTML entity.
  #
  def educate_dashes_oldschool(str)
    str.
      gsub(/---/, entity(:em_dash)).
      gsub(/--/,  entity(:en_dash))
  end

  # Return the string, with each instance of "--" translated
  # to an em-dash HTML entity, and each "---" translated to
  # an en-dash HTML entity. Two reasons why: First, unlike the en- and
  # em-dash syntax supported by +educate_dashes_oldschool+, it's
  # compatible with existing entries written before SmartyPants 1.1,
  # back when "--" was only used for em-dashes.  Second,
  # em-dashes are more common than en-dashes, and so it sort of makes
  # sense that the shortcut should be shorter to type. (Thanks to
  # Aaron Swartz for the idea.)
  #
  def educate_dashes_inverted(str)
    str.
      gsub(/---/, entity(:en_dash)).
      gsub(/--/,  entity(:em_dash))
  end

  # Return the string, with each instance of "..." translated
  # to an ellipsis HTML entity. Also converts the case where there are
  # spaces between the dots.
  #
  def educate_ellipses(str)
    str.
      gsub('...',   entity(:ellipsis)).
      gsub('. . .', entity(:ellipsis))
  end

  # Return the string, with "``backticks''"-style single quotes
  # translated into HTML curly quote entities.
  #
  def educate_backticks(str)
    str.
      gsub("``", entity(:double_left_quote)).
      gsub("''", entity(:double_right_quote))
  end

  # Return the string, with "`backticks'"-style single quotes
  # translated into HTML curly quote entities.
  #
  def educate_single_backticks(str)
    str.
      gsub("`", entity(:single_left_quote)).
      gsub("'", entity(:single_right_quote))
  end

  def educate_fractions(str)
    str.gsub(/(\s+|^)(1\/4|1\/2|3\/4)([,.;\s]|$)/) do
      frac =
        if $2 == "1/2".freeze
          entity(:frac12)
        elsif $2 == "1/4".freeze
          entity(:frac14)
        elsif $2 == "3/4".freeze
          entity(:frac34)
        end
      "#{$1}#{frac}#{$3}"
    end
  end

  # Return the string, with "educated" curly quote HTML entities.
  #
  def educate_quotes(str)
    punct_class = '[!"#\$\%\'()*+,\-.\/:;<=>?\@\[\\\\\]\^_`{|}~]'

    # normalize html
    str = str.dup
    # Special case if the very first character is a quote followed by
    # punctuation at a non-word-break. Close the quotes by brute
    # force:
    str.gsub!(/^'(?=#{punct_class}\B)/,
              entity(:single_right_quote))
    str.gsub!(/^"(?=#{punct_class}\B)/,
              entity(:double_right_quote))

    # Special case for double sets of quotes, e.g.:
    #   

He said, "'Quoted' words in a larger quote."

str.gsub!(/"'(?=\w)/, "#{entity(:double_left_quote)}#{entity(:single_left_quote)}") str.gsub!(/'"(?=\w)/, "#{entity(:single_left_quote)}#{entity(:double_left_quote)}") # Special case for decade abbreviations (the '80s): str.gsub!(/'(?=\d\ds)/, entity(:single_right_quote)) close_class = %![^\ \t\r\n\\[\{\(\-]! dec_dashes = "#{entity(:en_dash)}|#{entity(:em_dash)}" # Get most opening single quotes: str.gsub!(/(\s| |=|--|&[mn]dash;|#{dec_dashes}|ȁ[34];)'(?=\w)/, '\1' + entity(:single_left_quote)) # Single closing quotes: str.gsub!(/(#{close_class})'/, '\1' + entity(:single_right_quote)) str.gsub!(/'(\s|s\b|$)/, entity(:single_right_quote) + '\1') # Any remaining single quotes should be opening ones: str.gsub!(/'/, entity(:single_left_quote)) # Get most opening double quotes: str.gsub!(/(\s| |=|--|&[mn]dash;|#{dec_dashes}|ȁ[34];)"(?=\w)/, '\1' + entity(:double_left_quote)) # Double closing quotes: str.gsub!(/(#{close_class})"/, '\1' + entity(:double_right_quote)) str.gsub!(/"(\s|s\b|$)/, entity(:double_right_quote) + '\1') # Any remaining quotes should be opening ones: str.gsub!(/"/, entity(:double_left_quote)) str end # Return the string, with each RubyPants HTML entity translated to # its ASCII counterpart. # # Note: This is not reversible (but exactly the same as in SmartyPants) # def stupefy_entities(str) new_str = str.dup { :en_dash => '-', :em_dash => '--', :single_left_quote => "'", :single_right_quote => "'", :double_left_quote => '"', :double_right_quote => '"', :ellipsis => '...' }.each do |k,v| new_str.gsub!(/#{entity(k)}/, v) end new_str end # Return an array of the tokens comprising the string. Each token is # either a tag (possibly with nested, tags contained therein, such # as , or a run of text between # tags. Each element of the array is a two-element array; the first # is either :tag or :text; the second is the actual value. # # Based on the _tokenize() subroutine from Brad Choate's # MTRegex plugin. # # This is actually the easier variant using tag_soup, as used by # Chad Miller in the Python port of SmartyPants. # def tokenize tag_soup = /([^<]*)(<[^>]*>)/ tokens = [] prev_end = 0 scan(tag_soup) do tokens << [:text, $1] if $1 != "" tokens << [:tag, $2] prev_end = $~.end(0) end if prev_end < size tokens << [:text, self[prev_end..-1]] end tokens end def default_entities { single_left_quote: "‘", double_left_quote: "“", single_right_quote: "’", double_right_quote: "”", em_dash: "—", en_dash: "–", ellipsis: "…", html_quote: """, frac12: "½", frac14: "¼", frac34: "¾", } end def entity(key) @entities[key] end end