tag_collection.rb

    def process_text
      @text.scan(/((\[ (\/)? (\w+) ((=[^\[\]]+) | (\s\w+=\w+)* | ([^\]]*))? \]) | ([^\[]+))/ix) do |tag_info|
        @ti = TagInfo.new(tag_info, @defined_tags)
        
        @ti.handle_unregistered_tags_as_text # if the tag isn't in the @defined_tags list, then treat it as text
        return if !valid_element?
        
        # Validation of tag succeeded, add to @tags_list and/or bbtree
        if @ti.element_is_opening_tag?
          element = {:is_tag => true, :tag => @ti[:tag].to_sym, :nodes => [] }
          element[:params] = {:tag_param => @ti[:params][:tag_param]} if @ti.can_have_params? and @ti.has_params?
          @bbtree_current_node[:nodes] << BBTree.new(element) unless element.nil? # FIXME: It can't be nil here... but can elsewhere
          escalate_bbtree(element)
        elsif @ti.element_is_text?
          element = {:is_tag => false, :text => @ti.text }
          if within_open_tag?
            tag = @defined_tags[@bbtree_current_node[:tag]]
            if tag[:require_between]
              @bbtree_current_node[:between] = @ti[:text]
              if candidate_for_using_between_as_param?
                use_between_as_tag_param # Did not specify tag_param, so use between.
              end
              element = nil
            end
          end

          @bbtree_current_node[:nodes] << BBTree.new(element) unless element.nil?
          
        elsif @ti.element_is_closing_tag?
          retrogress_bbtree
        end
      end
      
      
      # if we're still expecting a closing tag and we've come to the end of the string... throw error
      if expecting_a_closing_tag?
        @errors = ["[#{@tags_list.to_sentence(RubyBBCode.to_sentence_bbcode_tags)}] not closed"]
        return
      end
    end