lib/rich_text.rb

   1 module RichText
   2   def self.new(format, text)
   3     case format
   4     when "html" then HTML.new(text || "")
   5     when "markdown" then Markdown.new(text || "")
   6     when "text" then Text.new(text || "")
   7     end
   8   end
   9
  10   class SimpleFormat
  11     include ActionView::Helpers::TextHelper
  12     include ActionView::Helpers::OutputSafetyHelper
  13
  14     def sanitize(text)
  15       Sanitize.clean(text, Sanitize::Config::OSM).html_safe
  16     end
  17   end
  18
  19   class Base < String
  20     include ActionView::Helpers::TagHelper
  21
  22     def spam_score
  23       link_count = 0
  24       link_size = 0
  25
  26       doc = Nokogiri::HTML(to_html)
  27
  28       if doc.content.empty?
  29         link_proportion = 0
  30       else
  31         doc.xpath("//a").each do |link|
  32           link_count += 1
  33           link_size += link.content.length
  34         end
  35
  36         link_proportion = link_size.to_f / doc.content.length.to_f
  37       end
  38
  39       [link_proportion - 0.2, 0.0].max * 200 + link_count * 40
  40     end
  41
  42     protected
  43
  44     def simple_format(text)
  45       SimpleFormat.new.simple_format(text)
  46     end
  47
  48     def linkify(text)
  49       if text.html_safe?
  50         Rinku.auto_link(text, :urls, tag_options(:rel => "nofollow")).html_safe
  51       else
  52         Rinku.auto_link(text, :urls, tag_options(:rel => "nofollow"))
  53       end
  54     end
  55   end
  56
  57   class HTML < Base
  58     def to_html
  59       linkify(sanitize(simple_format(self)))
  60     end
  61
  62     def to_text
  63       to_s
  64     end
  65
  66     private
  67
  68     def sanitize(text)
  69       Sanitize.clean(text, Sanitize::Config::OSM).html_safe
  70     end
  71   end
  72
  73   class Markdown < Base
  74     def to_html
  75       Markdown.html_parser.render(self).html_safe
  76     end
  77
  78     def to_text
  79       to_s
  80     end
  81
  82     def self.html_renderer
  83       @html_renderer ||= Renderer.new(:filter_html => true, :safe_links_only => true)
  84     end
  85
  86     def self.html_parser
  87       @html_parser ||= Redcarpet::Markdown.new(html_renderer, :no_intra_emphasis => true, :autolink => true, :space_after_headers => true)
  88     end
  89
  90     class Renderer < Redcarpet::Render::XHTML
  91       def link(link, _title, alt_text)
  92         "<a rel=\"nofollow\" href=\"#{link}\">#{alt_text}</a>"
  93       end
  94
  95       def autolink(link, link_type)
  96         if link_type == :email
  97           "<a rel=\"nofollow\" href=\"mailto:#{link}\">#{link}</a>"
  98         else
  99           "<a rel=\"nofollow\" href=\"#{link}\">#{link}</a>"
 100         end
 101       end
 102     end
 103   end
 104
 105   class Text < Base
 106     def to_html
 107       linkify(simple_format(ERB::Util.html_escape(self)))
 108     end
 109
 110     def to_text
 111       to_s
 112     end
 113   end
 114 end