class ExcerptParser < Nokogiri::XML::SAX::Document attr_reader :excerpt SPAN_REGEX = /<\s*span[^>]*class\s*=\s*['|"]excerpt['|"][^>]*>/ def initialize(length, options=nil) @length = length @excerpt = "" @current_length = 0 options || {} @strip_links = options[:strip_links] == true @text_entities = options[:text_entities] == true @markdown_images = options[:markdown_images] == true @start_excerpt = false end def self.get_excerpt(html, length, options) html ||= '' if (html.include? 'excerpt') && (SPAN_REGEX === html) length = html.length end me = self.new(length, options) parser = Nokogiri::HTML::SAX::Parser.new(me) catch(:done) do parser.parse(html) end me.excerpt.strip! me.excerpt end def escape_attribute(v) v.gsub("&", "&") .gsub("\"", """) .gsub("<", "<") .gsub(">", ">") end def include_tag(name, attributes) characters("<#{name} #{attributes.map{|k,v| "#{k}=\"#{escape_attribute(v)}\""}.join(' ')}>", false, false, false) end def start_element(name, attributes=[]) case name when "img" # If include_images is set, include the image in markdown characters("!") if @markdown_images attributes = Hash[*attributes.flatten] if attributes["alt"] characters("[#{attributes["alt"]}]") elsif attributes["title"] characters("[#{attributes["title"]}]") else characters("[image]") end characters("(#{attributes['src']})") if @markdown_images when "a" unless @strip_links include_tag(name, attributes) @in_a = true end when "aside" @in_quote = true when "div", "span" if attributes.include?(["class", "excerpt"]) @excerpt = "" @current_length = 0 @start_excerpt = true end # Preserve spoilers if attributes.include?(["class", "spoiler"]) include_tag("span", attributes) @in_spoiler = true end end end def end_element(name) case name when "a" unless @strip_links characters("",false, false, false) @in_a = false end when "p", "br" characters(" ") when "aside" @in_quote = false when "div", "span" throw :done if @start_excerpt characters("", false, false, false) if @in_spoiler @in_spoiler = false end end def characters(string, truncate = true, count_it = true, encode = true) return if @in_quote encode = encode ? lambda{|s| ERB::Util.html_escape(s)} : lambda {|s| s} if count_it && @current_length + string.length > @length length = [0, @length - @current_length - 1].max @excerpt << encode.call(string[0..length]) if truncate @excerpt << (@text_entities ? "..." : "…") @excerpt << "" if @in_a throw :done end @excerpt << encode.call(string) @current_length += string.length if count_it end end