vendor/rails/actionpack/lib/action_view/helpers/text_helper.rb

   1 require 'action_view/helpers/tag_helper'
   2
   3 begin
   4   require 'html/document'
   5 rescue LoadError
   6   html_scanner_path = "#{File.dirname(__FILE__)}/../../action_controller/vendor/html-scanner"
   7   if File.directory?(html_scanner_path)
   8     $:.unshift html_scanner_path
   9     require 'html/document'
  10   end
  11 end
  12
  13 module ActionView
  14   module Helpers #:nodoc:
  15     # The TextHelper module provides a set of methods for filtering, formatting
  16     # and transforming strings, which can reduce the amount of inline Ruby code in
  17     # your views. These helper methods extend ActionView making them callable
  18     # within your template files.
  19     module TextHelper
  20       # The preferred method of outputting text in your views is to use the
  21       # <%= "text" %> eRuby syntax. The regular _puts_ and _print_ methods
  22       # do not operate as expected in an eRuby code block. If you absolutely must
  23       # output text within a non-output code block (i.e., <% %>), you can use the concat method.
  24       #
  25       # ==== Examples
  26       #   <%
  27       #       concat "hello"
  28       #       # is the equivalent of <%= "hello" %>
  29       #
  30       #       if (logged_in == true):
  31       #         concat "Logged in!"
  32       #       else
  33       #         concat link_to('login', :action => login)
  34       #       end
  35       #       # will either display "Logged in!" or a login link
  36       #   %>
  37       def concat(string, unused_binding = nil)
  38         if unused_binding
  39           ActiveSupport::Deprecation.warn("The binding argument of #concat is no longer needed.  Please remove it from your views and helpers.", caller)
  40         end
  41
  42         output_buffer << string
  43       end
  44
  45       # Truncates a given +text+ after a given <tt>:length</tt> if +text+ is longer than <tt>:length</tt>
  46       # (defaults to 30). The last characters will be replaced with the <tt>:omission</tt> (defaults to "...").
  47       #
  48       # ==== Examples
  49       #
  50       #   truncate("Once upon a time in a world far far away")
  51       #   # => Once upon a time in a world f...
  52       #
  53       #   truncate("Once upon a time in a world far far away", :length => 14)
  54       #   # => Once upon a...
  55       #
  56       #   truncate("And they found that many people were sleeping better.", :length => 25, "(clipped)")
  57       #   # => And they found that many (clipped)
  58       #
  59       #   truncate("And they found that many people were sleeping better.", :omission => "... (continued)", :length => 15)
  60       #   # => And they found... (continued)
  61       #
  62       # You can still use <tt>truncate</tt> with the old API that accepts the
  63       # +length+ as its optional second and the +ellipsis+ as its
  64       # optional third parameter:
  65       #   truncate("Once upon a time in a world far far away", 14)
  66       #   # => Once upon a time in a world f...
  67       #
  68       #   truncate("And they found that many people were sleeping better.", 15, "... (continued)")
  69       #   # => And they found... (continued)
  70       def truncate(text, *args)
  71         options = args.extract_options!
  72         unless args.empty?
  73           ActiveSupport::Deprecation.warn('truncate takes an option hash instead of separate ' +
  74             'length and omission arguments', caller)
  75
  76           options[:length] = args[0] || 30
  77           options[:omission] = args[1] || "..."
  78         end
  79         options.reverse_merge!(:length => 30, :omission => "...")
  80
  81         if text
  82           l = options[:length] - options[:omission].mb_chars.length
  83           chars = text.mb_chars
  84           (chars.length > options[:length] ? chars[0...l] + options[:omission] : text).to_s
  85         end
  86       end
  87
  88       # Highlights one or more +phrases+ everywhere in +text+ by inserting it into
  89       # a <tt>:highlighter</tt> string. The highlighter can be specialized by passing <tt>:highlighter</tt>
  90       # as a single-quoted string with \1 where the phrase is to be inserted (defaults to
  91       # '<strong class="highlight">\1</strong>')
  92       #
  93       # ==== Examples
  94       #   highlight('You searched for: rails', 'rails')
  95       #   # => You searched for: <strong class="highlight">rails</strong>
  96       #
  97       #   highlight('You searched for: ruby, rails, dhh', 'actionpack')
  98       #   # => You searched for: ruby, rails, dhh
  99       #
 100       #   highlight('You searched for: rails', ['for', 'rails'], :highlighter => '<em>\1</em>')
 101       #   # => You searched <em>for</em>: <em>rails</em>
 102       #
 103       #   highlight('You searched for: rails', 'rails', :highlighter => '<a href="search?q=\1">\1</a>')
 104       #   # => You searched for: <a href="search?q=rails">rails</a>
 105       #
 106       # You can still use <tt>highlight</tt> with the old API that accepts the
 107       # +highlighter+ as its optional third parameter:
 108       #   highlight('You searched for: rails', 'rails', '<a href="search?q=\1">\1</a>')     # => You searched for: <a href="search?q=rails">rails</a>
 109       def highlight(text, phrases, *args)
 110         options = args.extract_options!
 111         unless args.empty?
 112           options[:highlighter] = args[0] || '<strong class="highlight">\1</strong>'
 113         end
 114         options.reverse_merge!(:highlighter => '<strong class="highlight">\1</strong>')
 115
 116         if text.blank? || phrases.blank?
 117           text
 118         else
 119           match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
 120           text.gsub(/(#{match})/i, options[:highlighter])
 121         end
 122       end
 123
 124       # Extracts an excerpt from +text+ that matches the first instance of +phrase+.
 125       # The <tt>:radius</tt> option expands the excerpt on each side of the first occurrence of +phrase+ by the number of characters
 126       # defined in <tt>:radius</tt> (which defaults to 100). If the excerpt radius overflows the beginning or end of the +text+,
 127       # then the <tt>:omission</tt> option (which defaults to "...") will be prepended/appended accordingly. The resulting string
 128       # will be stripped in any case. If the +phrase+ isn't found, nil is returned.
 129       #
 130       # ==== Examples
 131       #   excerpt('This is an example', 'an', :radius => 5)
 132       #   # => ...s is an exam...
 133       #
 134       #   excerpt('This is an example', 'is', :radius => 5)
 135       #   # => This is a...
 136       #
 137       #   excerpt('This is an example', 'is')
 138       #   # => This is an example
 139       #
 140       #   excerpt('This next thing is an example', 'ex', :radius => 2)
 141       #   # => ...next...
 142       #
 143       #   excerpt('This is also an example', 'an', :radius => 8, :omission => '<chop> ')
 144       #   # => <chop> is also an example
 145       #
 146       # You can still use <tt>excerpt</tt> with the old API that accepts the
 147       # +radius+ as its optional third and the +ellipsis+ as its
 148       # optional forth parameter:
 149       #   excerpt('This is an example', 'an', 5)                   # => ...s is an exam...
 150       #   excerpt('This is also an example', 'an', 8, '<chop> ')   # => <chop> is also an example
 151       def excerpt(text, phrase, *args)
 152         options = args.extract_options!
 153         unless args.empty?
 154           options[:radius] = args[0] || 100
 155           options[:omission] = args[1] || "..."
 156         end
 157         options.reverse_merge!(:radius => 100, :omission => "...")
 158
 159         if text && phrase
 160           phrase = Regexp.escape(phrase)
 161
 162           if found_pos = text.mb_chars =~ /(#{phrase})/i
 163             start_pos = [ found_pos - options[:radius], 0 ].max
 164             end_pos   = [ [ found_pos + phrase.mb_chars.length + options[:radius] - 1, 0].max, text.mb_chars.length ].min
 165
 166             prefix  = start_pos > 0 ? options[:omission] : ""
 167             postfix = end_pos < text.mb_chars.length - 1 ? options[:omission] : ""
 168
 169             prefix + text.mb_chars[start_pos..end_pos].strip + postfix
 170           else
 171             nil
 172           end
 173         end
 174       end
 175
 176       # Attempts to pluralize the +singular+ word unless +count+ is 1. If
 177       # +plural+ is supplied, it will use that when count is > 1, otherwise
 178       # it will use the Inflector to determine the plural form
 179       #
 180       # ==== Examples
 181       #   pluralize(1, 'person')
 182       #   # => 1 person
 183       #
 184       #   pluralize(2, 'person')
 185       #   # => 2 people
 186       #
 187       #   pluralize(3, 'person', 'users')
 188       #   # => 3 users
 189       #
 190       #   pluralize(0, 'person')
 191       #   # => 0 people
 192       def pluralize(count, singular, plural = nil)
 193         "#{count || 0} " + ((count == 1 || count == '1') ? singular : (plural || singular.pluralize))
 194       end
 195
 196       # Wraps the +text+ into lines no longer than +line_width+ width. This method
 197       # breaks on the first whitespace character that does not exceed +line_width+
 198       # (which is 80 by default).
 199       #
 200       # ==== Examples
 201       #
 202       #   word_wrap('Once upon a time')
 203       #   # => Once upon a time
 204       #
 205       #   word_wrap('Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding a successor to the throne turned out to be more trouble than anyone could have imagined...')
 206       #   # => Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding\n a successor to the throne turned out to be more trouble than anyone could have\n imagined...
 207       #
 208       #   word_wrap('Once upon a time', :line_width => 8)
 209       #   # => Once upon\na time
 210       #
 211       #   word_wrap('Once upon a time', :line_width => 1)
 212       #   # => Once\nupon\na\ntime
 213       #
 214       # You can still use <tt>word_wrap</tt> with the old API that accepts the
 215       # +line_width+ as its optional second parameter:
 216       #   word_wrap('Once upon a time', 8)     # => Once upon\na time
 217       def word_wrap(text, *args)
 218         options = args.extract_options!
 219         unless args.blank?
 220           options[:line_width] = args[0] || 80
 221         end
 222         options.reverse_merge!(:line_width => 80)
 223
 224         text.split("\n").collect do |line|
 225           line.length > options[:line_width] ? line.gsub(/(.{1,#{options[:line_width]}})(\s+|$)/, "\\1\n").strip : line
 226         end * "\n"
 227       end
 228
 229       begin
 230         require_library_or_gem "redcloth" unless Object.const_defined?(:RedCloth)
 231
 232         # Returns the text with all the Textile[http://www.textism.com/tools/textile] codes turned into HTML tags.
 233         #
 234         # You can learn more about Textile's syntax at its website[http://www.textism.com/tools/textile].
 235         # <i>This method is only available if RedCloth[http://whytheluckystiff.net/ruby/redcloth/]
 236         # is available</i>.
 237         #
 238         # ==== Examples
 239         #   textilize("*This is Textile!*  Rejoice!")
 240         #   # => "<p><strong>This is Textile!</strong>  Rejoice!</p>"
 241         #
 242         #   textilize("I _love_ ROR(Ruby on Rails)!")
 243         #   # => "<p>I <em>love</em> <acronym title="Ruby on Rails">ROR</acronym>!</p>"
 244         #
 245         #   textilize("h2. Textile makes markup -easy- simple!")
 246         #   # => "<h2>Textile makes markup <del>easy</del> simple!</h2>"
 247         #
 248         #   textilize("Visit the Rails website "here":http://www.rubyonrails.org/.)
 249         #   # => "<p>Visit the Rails website <a href="http://www.rubyonrails.org/">here</a>.</p>"
 250         def textilize(text)
 251           if text.blank?
 252             ""
 253           else
 254             textilized = RedCloth.new(text, [ :hard_breaks ])
 255             textilized.hard_breaks = true if textilized.respond_to?(:hard_breaks=)
 256             textilized.to_html
 257           end
 258         end
 259
 260         # Returns the text with all the Textile codes turned into HTML tags,
 261         # but without the bounding <p> tag that RedCloth adds.
 262         #
 263         # You can learn more about Textile's syntax at its website[http://www.textism.com/tools/textile].
 264         # <i>This method is only available if RedCloth[http://whytheluckystiff.net/ruby/redcloth/]
 265         # is available</i>.
 266         #
 267         # ==== Examples
 268         #   textilize_without_paragraph("*This is Textile!*  Rejoice!")
 269         #   # => "<strong>This is Textile!</strong>  Rejoice!"
 270         #
 271         #   textilize_without_paragraph("I _love_ ROR(Ruby on Rails)!")
 272         #   # => "I <em>love</em> <acronym title="Ruby on Rails">ROR</acronym>!"
 273         #
 274         #   textilize_without_paragraph("h2. Textile makes markup -easy- simple!")
 275         #   # => "<h2>Textile makes markup <del>easy</del> simple!</h2>"
 276         #
 277         #   textilize_without_paragraph("Visit the Rails website "here":http://www.rubyonrails.org/.)
 278         #   # => "Visit the Rails website <a href="http://www.rubyonrails.org/">here</a>."
 279         def textilize_without_paragraph(text)
 280           textiled = textilize(text)
 281           if textiled[0..2] == "<p>" then textiled = textiled[3..-1] end
 282           if textiled[-4..-1] == "</p>" then textiled = textiled[0..-5] end
 283           return textiled
 284         end
 285       rescue LoadError
 286         # We can't really help what's not there
 287       end
 288
 289       begin
 290         require_library_or_gem "bluecloth" unless Object.const_defined?(:BlueCloth)
 291
 292         # Returns the text with all the Markdown codes turned into HTML tags.
 293         # <i>This method is only available if BlueCloth[http://www.deveiate.org/projects/BlueCloth]
 294         # is available</i>.
 295         #
 296         # ==== Examples
 297         #   markdown("We are using __Markdown__ now!")
 298         #   # => "<p>We are using <strong>Markdown</strong> now!</p>"
 299         #
 300         #   markdown("We like to _write_ `code`, not just _read_ it!")
 301         #   # => "<p>We like to <em>write</em> <code>code</code>, not just <em>read</em> it!</p>"
 302         #
 303         #   markdown("The [Markdown website](http://daringfireball.net/projects/markdown/) has more information.")
 304         #   # => "<p>The <a href="http://daringfireball.net/projects/markdown/">Markdown website</a>
 305         #   #     has more information.</p>"
 306         #
 307         #   markdown('![The ROR logo](http://rubyonrails.com/images/rails.png "Ruby on Rails")')
 308         #   # => '<p><img src="http://rubyonrails.com/images/rails.png" alt="The ROR logo" title="Ruby on Rails" /></p>'
 309         def markdown(text)
 310           text.blank? ? "" : BlueCloth.new(text).to_html
 311         end
 312       rescue LoadError
 313         # We can't really help what's not there
 314       end
 315
 316       # Returns +text+ transformed into HTML using simple formatting rules.
 317       # Two or more consecutive newlines(<tt>\n\n</tt>) are considered as a
 318       # paragraph and wrapped in <tt><p></tt> tags. One newline (<tt>\n</tt>) is
 319       # considered as a linebreak and a <tt><br /></tt> tag is appended. This
 320       # method does not remove the newlines from the +text+.
 321       #
 322       # You can pass any HTML attributes into <tt>html_options</tt>.  These
 323       # will be added to all created paragraphs.
 324       # ==== Examples
 325       #   my_text = "Here is some basic text...\n...with a line break."
 326       #
 327       #   simple_format(my_text)
 328       #   # => "<p>Here is some basic text...\n<br />...with a line break.</p>"
 329       #
 330       #   more_text = "We want to put a paragraph...\n\n...right there."
 331       #
 332       #   simple_format(more_text)
 333       #   # => "<p>We want to put a paragraph...</p>\n\n<p>...right there.</p>"
 334       #
 335       #   simple_format("Look ma! A class!", :class => 'description')
 336       #   # => "<p class='description'>Look ma! A class!</p>"
 337       def simple_format(text, html_options={})
 338         start_tag = tag('p', html_options, true)
 339         text = text.to_s.dup
 340         text.gsub!(/\r\n?/, "\n")                    # \r\n and \r -> \n
 341         text.gsub!(/\n\n+/, "</p>\n\n#{start_tag}")  # 2+ newline  -> paragraph
 342         text.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') # 1 newline   -> br
 343         text.insert 0, start_tag
 344         text << "</p>"
 345       end
 346
 347       # Turns all URLs and e-mail addresses into clickable links. The <tt>:link</tt> option
 348       # will limit what should be linked. You can add HTML attributes to the links using
 349       # <tt>:href_options</tt>. Possible values for <tt>:link</tt> are <tt>:all</tt> (default),
 350       # <tt>:email_addresses</tt>, and <tt>:urls</tt>. If a block is given, each URL and
 351       # e-mail address is yielded and the result is used as the link text.
 352       #
 353       # ==== Examples
 354       #   auto_link("Go to http://www.rubyonrails.org and say hello to david@loudthinking.com")
 355       #   # => "Go to <a href=\"http://www.rubyonrails.org\">http://www.rubyonrails.org</a> and
 356       #   #     say hello to <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"
 357       #
 358       #   auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :link => :urls)
 359       #   # => "Visit <a href=\"http://www.loudthinking.com/\">http://www.loudthinking.com/</a>
 360       #   #     or e-mail david@loudthinking.com"
 361       #
 362       #   auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :link => :email_addresses)
 363       #   # => "Visit http://www.loudthinking.com/ or e-mail <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"
 364       #
 365       #   post_body = "Welcome to my new blog at http://www.myblog.com/.  Please e-mail me at me@email.com."
 366       #   auto_link(post_body, :href_options => { :target => '_blank' }) do |text|
 367       #     truncate(text, 15)
 368       #   end
 369       #   # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\" target=\"_blank\">http://www.m...</a>.
 370       #         Please e-mail me at <a href=\"mailto:me@email.com\">me@email.com</a>."
 371       #
 372       #
 373       # You can still use <tt>auto_link</tt> with the old API that accepts the
 374       # +link+ as its optional second parameter and the +html_options+ hash
 375       # as its optional third parameter:
 376       #   post_body = "Welcome to my new blog at http://www.myblog.com/. Please e-mail me at me@email.com."
 377       #   auto_link(post_body, :urls)     # => Once upon\na time
 378       #   # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\">http://www.myblog.com</a>.
 379       #         Please e-mail me at me@email.com."
 380       #
 381       #   auto_link(post_body, :all, :target => "_blank")     # => Once upon\na time
 382       #   # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\" target=\"_blank\">http://www.myblog.com</a>.
 383       #         Please e-mail me at <a href=\"mailto:me@email.com\">me@email.com</a>."
 384       def auto_link(text, *args, &block)#link = :all, href_options = {}, &block)
 385         return '' if text.blank?
 386
 387         options = args.size == 2 ? {} : args.extract_options! # this is necessary because the old auto_link API has a Hash as its last parameter
 388         unless args.empty?
 389           options[:link] = args[0] || :all
 390           options[:html] = args[1] || {}
 391         end
 392         options.reverse_merge!(:link => :all, :html => {})
 393
 394         case options[:link].to_sym
 395           when :all                         then auto_link_email_addresses(auto_link_urls(text, options[:html], &block), &block)
 396           when :email_addresses             then auto_link_email_addresses(text, &block)
 397           when :urls                        then auto_link_urls(text, options[:html], &block)
 398         end
 399       end
 400
 401       # Creates a Cycle object whose _to_s_ method cycles through elements of an
 402       # array every time it is called. This can be used for example, to alternate
 403       # classes for table rows.  You can use named cycles to allow nesting in loops.
 404       # Passing a Hash as the last parameter with a <tt>:name</tt> key will create a
 405       # named cycle. The default name for a cycle without a +:name+ key is
 406       # <tt>"default"</tt>. You can manually reset a cycle by calling reset_cycle
 407       # and passing the name of the cycle. The current cycle string can be obtained
 408       # anytime using the current_cycle method.
 409       #
 410       # ==== Examples
 411       #   # Alternate CSS classes for even and odd numbers...
 412       #   @items = [1,2,3,4]
 413       #   <table>
 414       #   <% @items.each do |item| %>
 415       #     <tr class="<%= cycle("even", "odd") -%>">
 416       #       <td>item</td>
 417       #     </tr>
 418       #   <% end %>
 419       #   </table>
 420       #
 421       #
 422       #   # Cycle CSS classes for rows, and text colors for values within each row
 423       #   @items = x = [{:first => 'Robert', :middle => 'Daniel', :last => 'James'},
 424       #                {:first => 'Emily', :middle => 'Shannon', :maiden => 'Pike', :last => 'Hicks'},
 425       #               {:first => 'June', :middle => 'Dae', :last => 'Jones'}]
 426       #   <% @items.each do |item| %>
 427       #     <tr class="<%= cycle("even", "odd", :name => "row_class") -%>">
 428       #       <td>
 429       #         <% item.values.each do |value| %>
 430       #           <%# Create a named cycle "colors" %>
 431       #           <span style="color:<%= cycle("red", "green", "blue", :name => "colors") -%>">
 432       #             <%= value %>
 433       #           </span>
 434       #         <% end %>
 435       #         <% reset_cycle("colors") %>
 436       #       </td>
 437       #    </tr>
 438       #  <% end %>
 439       def cycle(first_value, *values)
 440         if (values.last.instance_of? Hash)
 441           params = values.pop
 442           name = params[:name]
 443         else
 444           name = "default"
 445         end
 446         values.unshift(first_value)
 447
 448         cycle = get_cycle(name)
 449         if (cycle.nil? || cycle.values != values)
 450           cycle = set_cycle(name, Cycle.new(*values))
 451         end
 452         return cycle.to_s
 453       end
 454
 455       # Returns the current cycle string after a cycle has been started. Useful
 456       # for complex table highlighing or any other design need which requires
 457       # the current cycle string in more than one place.
 458       #
 459       # ==== Example
 460       #   # Alternate background colors
 461       #   @items = [1,2,3,4]
 462       #   <% @items.each do |item| %>
 463       #     <div style="background-color:<%= cycle("red","white","blue") %>">
 464       #       <span style="background-color:<%= current_cycle %>"><%= item %></span>
 465       #     </div>
 466       #   <% end %>
 467       def current_cycle(name = "default")
 468         cycle = get_cycle(name)
 469         cycle.current_value unless cycle.nil?
 470       end
 471
 472       # Resets a cycle so that it starts from the first element the next time
 473       # it is called. Pass in +name+ to reset a named cycle.
 474       #
 475       # ==== Example
 476       #   # Alternate CSS classes for even and odd numbers...
 477       #   @items = [[1,2,3,4], [5,6,3], [3,4,5,6,7,4]]
 478       #   <table>
 479       #   <% @items.each do |item| %>
 480       #     <tr class="<%= cycle("even", "odd") -%>">
 481       #         <% item.each do |value| %>
 482       #           <span style="color:<%= cycle("#333", "#666", "#999", :name => "colors") -%>">
 483       #             <%= value %>
 484       #           </span>
 485       #         <% end %>
 486       #
 487       #         <% reset_cycle("colors") %>
 488       #     </tr>
 489       #   <% end %>
 490       #   </table>
 491       def reset_cycle(name = "default")
 492         cycle = get_cycle(name)
 493         cycle.reset unless cycle.nil?
 494       end
 495
 496       class Cycle #:nodoc:
 497         attr_reader :values
 498
 499         def initialize(first_value, *values)
 500           @values = values.unshift(first_value)
 501           reset
 502         end
 503
 504         def reset
 505           @index = 0
 506         end
 507
 508         def current_value
 509           @values[previous_index].to_s
 510         end
 511
 512         def to_s
 513           value = @values[@index].to_s
 514           @index = next_index
 515           return value
 516         end
 517
 518         private
 519
 520         def next_index
 521           step_index(1)
 522         end
 523
 524         def previous_index
 525           step_index(-1)
 526         end
 527
 528         def step_index(n)
 529           (@index + n) % @values.size
 530         end
 531       end
 532
 533       private
 534         # The cycle helpers need to store the cycles in a place that is
 535         # guaranteed to be reset every time a page is rendered, so it
 536         # uses an instance variable of ActionView::Base.
 537         def get_cycle(name)
 538           @_cycles = Hash.new unless defined?(@_cycles)
 539           return @_cycles[name]
 540         end
 541
 542         def set_cycle(name, cycle_object)
 543           @_cycles = Hash.new unless defined?(@_cycles)
 544           @_cycles[name] = cycle_object
 545         end
 546
 547         AUTO_LINK_RE = %r{
 548                         (                          # leading text
 549                           <\w+.*?>|                # leading HTML tag, or
 550                           [^=!:'"/]|               # leading punctuation, or
 551                           ^                        # beginning of line
 552                         )
 553                         (
 554                           (?:https?://)|           # protocol spec, or
 555                           (?:www\.)                # www.*
 556                         )
 557                         (
 558                           [-\w]+                   # subdomain or domain
 559                           (?:\.[-\w]+)*            # remaining subdomains or domain
 560                           (?::\d+)?                # port
 561                           (?:/(?:[~\w\+@%=\(\)-]|(?:[,.;:'][^\s$]))*)* # path
 562                           (?:\?[\w\+@%&=.;:-]+)?     # query string
 563                           (?:\#[\w\-]*)?           # trailing anchor
 564                         )
 565                         ([[:punct:]]|<|$|)       # trailing text
 566                        }x unless const_defined?(:AUTO_LINK_RE)
 567
 568         # Turns all urls into clickable links.  If a block is given, each url
 569         # is yielded and the result is used as the link text.
 570         def auto_link_urls(text, html_options = {})
 571           extra_options = tag_options(html_options.stringify_keys) || ""
 572           text.gsub(AUTO_LINK_RE) do
 573             all, a, b, c, d = $&, $1, $2, $3, $4
 574             if a =~ /<a\s/i # don't replace URL's that are already linked
 575               all
 576             else
 577               text = b + c
 578               text = yield(text) if block_given?
 579               %(#{a}<a href="#{b=="www."?"http://www.":b}#{c}"#{extra_options}>#{text}</a>#{d})
 580             end
 581           end
 582         end
 583
 584         # Turns all email addresses into clickable links.  If a block is given,
 585         # each email is yielded and the result is used as the link text.
 586         def auto_link_email_addresses(text)
 587           body = text.dup
 588           text.gsub(/([\w\.!#\$%\-+.]+@[A-Za-z0-9\-]+(\.[A-Za-z0-9\-]+)+)/) do
 589             text = $1
 590
 591             if body.match(/<a\b[^>]*>(.*)(#{Regexp.escape(text)})(.*)<\/a>/)
 592               text
 593             else
 594               display_text = (block_given?) ? yield(text) : text
 595               %{<a href="mailto:#{text}">#{display_text}</a>}
 596             end
 597           end
 598         end
 599     end
 600   end
 601 end