Class: Pipio::TagBalancer

Inherits:
Object
  • Object
show all
Defined in:
lib/pipio/tag_balancer.rb

Overview

From Wordpress’s formatting.php; rewritten in Ruby by Gabe Berke-Williams, 2009.

Author

Leonard Lin <[email protected]>

License

GPL v2.0

Copyright

November 4, 2001

Instance Method Summary collapse

Constructor Details

#initialize(text) ⇒ TagBalancer

Returns a new instance of TagBalancer.



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# File 'lib/pipio/tag_balancer.rb', line 12

def initialize(text)
  @text = text

  @tagstack  = []
  @stacksize = 0
  @tagqueue  = ''

  # Known single-entity/self-closing tags
  @self_closing_tags = %w(br hr img input meta)

  # Tags that can be immediately nested within themselves
  @nestable_tags = %w(blockquote div span font)

  # 1: tagname, with possible leading "/"
  # 2: attributes
  @tag_regex = /<(\/?\w*)\s*([^>]*)>/
end

Instance Method Details

#balance ⇒ Object 



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# File 'lib/pipio/tag_balancer.rb', line 30

def balance
  text    = @text.dup
  newtext = ''

  @tagstack  = []
  @stacksize = 0
  @tagqueue  = ''

  # WP bug fix for comments - in case you REALLY meant to type '< !--'
  text.gsub!('< !--', '<    !--')

  # WP bug fix for LOVE <3 (and other situations with '<' before a number)
  text.gsub!(/<([0-9]{1})/, '&lt;\1')

  while ( pos = (text =~ @tag_regex) )
    newtext << @tagqueue
    tag        = $1.downcase
    attributes = $2
    matchlen   = $~[0].size

    # clear the shifter
    @tagqueue = ''
    # Pop or Push
    if end_tag?(tag)
      tag.slice!(0,1)
      if too_many_closing_tags?
        tag = ''
        #or close to be safe: tag = '/' << tag
      elsif closing_tag?(tag)
        # if stacktop value == tag close value then pop
        tag = "</#{tag}>" # Close Tag
        @tagstack.pop
        @stacksize -= 1
      else
        # closing tag not at top, search for it
        (@stacksize-1).downto(0) do |j|
          if @tagstack[j] == tag
            # add tag to tagqueue
            ss = @stacksize - 1
            ss.downto(j) do |k|
              @tagqueue << "</#{@tagstack.pop}>"
              @stacksize -= 1
            end

            break
          end
        end
        tag = ''
      end
    else
      # Begin Tag

      # Tag Cleaning
      if self_closing_attributes?(attributes) || empty_tag?(tag)
      elsif self_closing_tag?(tag)
        # ElseIf: it's a known single-entity tag but it doesn't close itself, do so
        attributes << '/'
      else
        # Push the tag onto the stack
        # If the top of the stack is the same as the tag we want to push, close previous tag
        if (@stacksize > 0 &&
            ! nestable?(tag) &&
            @tagstack[@stacksize - 1] == tag)
          @tagqueue = "</#{@tagstack.pop}>"
          @stacksize -= 1
        end
        @tagstack.push(tag)
        @stacksize += 1
      end

      # Attributes
      if attributes != ''
        attributes = ' ' + attributes
      end
      tag = "<#{tag}#{attributes}>"
      #If already queuing a close tag, then put this tag on, too
      if @tagqueue
        @tagqueue << tag
        tag = ''
      end
    end
    newtext << text[0,pos] << tag
    text = text[pos+matchlen, text.length - (pos+matchlen)]
  end

  # Clear Tag Queue
  newtext << @tagqueue

  # Add Remaining text
  newtext << text

  # Empty Stack
  @tagstack.reverse_each do |t|
    newtext << "</#{t}>" # Add remaining tags to close
  end

  # WP fix for the bug with HTML comments
  newtext.gsub!("< !--", "<!--")
  newtext.gsub!("<    !--", "< !--")

  newtext
end