The TextHelper module provides a set of methods for filtering, formatting and transforming strings, which can reduce the amount of inline Ruby code in your views. These helper methods extend ActionView making them callable within your template files.

Methods
Constants
AUTO_LINK_RE = %r{ (?: ([\w+.:-]+:)// | www\. ) [^\s<]+ }x
AUTO_LINK_CRE = [/<[^>]+$/, /^[^>]*>/, /<a\b.*?>/i, /<\/a>/i]
  regexps for determining context, used high-volume
AUTO_EMAIL_RE = /[\w.!#\$%+-]+@[\w-]+(?:\.[\w-]+)+/
BRACKETS = { ']' => '[', ')' => '(', '}' => '{' }
Public Instance methods
auto_link(text, *args, &block)

Turns all URLs and e-mail addresses into clickable links. The :link option will limit what should be linked. You can add HTML attributes to the links using :href_options. Possible values for :link are :all (default), :email_addresses, and :urls. If a block is given, each URL and e-mail address is yielded and the result is used as the link text.

Examples

  auto_link("Go to http://www.rubyonrails.org and say hello to david@loudthinking.com")
  # => "Go to <a href=\"http://www.rubyonrails.org\">http://www.rubyonrails.org</a> and
  #     say hello to <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"

  auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :link => :urls)
  # => "Visit <a href=\"http://www.loudthinking.com/\">http://www.loudthinking.com/</a>
  #     or e-mail david@loudthinking.com"

  auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :link => :email_addresses)
  # => "Visit http://www.loudthinking.com/ or e-mail <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"

  post_body = "Welcome to my new blog at http://www.myblog.com/.  Please e-mail me at me@email.com."
  auto_link(post_body, :href_options => { :target => '_blank' }) do |text|
    truncate(text, 15)
  end
  # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\" target=\"_blank\">http://www.m...</a>.
        Please e-mail me at <a href=\"mailto:me@email.com\">me@email.com</a>."

You can still use auto_link with the old API that accepts the link as its optional second parameter and the html_options hash as its optional third parameter:

  post_body = "Welcome to my new blog at http://www.myblog.com/. Please e-mail me at me@email.com."
  auto_link(post_body, :urls)     # => Once upon\na time
  # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\">http://www.myblog.com</a>.
        Please e-mail me at me@email.com."

  auto_link(post_body, :all, :target => "_blank")     # => Once upon\na time
  # => "Welcome to my new blog at <a href=\"http://www.myblog.com/\" target=\"_blank\">http://www.myblog.com</a>.
        Please e-mail me at <a href=\"mailto:me@email.com\">me@email.com</a>."
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 371
371:       def auto_link(text, *args, &block)#link = :all, href_options = {}, &block)
372:         return '' if text.blank?
373: 
374:         options = args.size == 2 ? {} : args.extract_options! # this is necessary because the old auto_link API has a Hash as its last parameter
375:         unless args.empty?
376:           options[:link] = args[0] || :all
377:           options[:html] = args[1] || {}
378:         end
379:         options.reverse_merge!(:link => :all, :html => {})
380: 
381:         case options[:link].to_sym
382:           when :all                         then auto_link_email_addresses(auto_link_urls(text, options[:html], &block), options[:html], &block)
383:           when :email_addresses             then auto_link_email_addresses(text, options[:html], &block)
384:           when :urls                        then auto_link_urls(text, options[:html], &block)
385:         end
386:       end
concat(string, unused_binding = nil)

The preferred method of outputting text in your views is to use the <%= "text" %> eRuby syntax. The regular puts and print methods do not operate as expected in an eRuby code block. If you absolutely must output text within a non-output code block (i.e., <% %>), you can use the concat method.

Examples

  <%
      concat "hello"
      # is the equivalent of <%= "hello" %>

      if (logged_in == true):
        concat "Logged in!"
      else
        concat link_to('login', :action => login)
      end
      # will either display "Logged in!" or a login link
  %>
    # File actionpack/lib/action_view/helpers/text_helper.rb, line 27
27:       def concat(string, unused_binding = nil)
28:         if unused_binding
29:           ActiveSupport::Deprecation.warn("The binding argument of #concat is no longer needed.  Please remove it from your views and helpers.", caller)
30:         end
31: 
32:         output_buffer.safe_concat(string)
33:       end
current_cycle(name = "default")

Returns the current cycle string after a cycle has been started. Useful for complex table highlighing or any other design need which requires the current cycle string in more than one place.

Example

  # Alternate background colors
  @items = [1,2,3,4]
  <% @items.each do |item| %>
    <div style="background-color:<%= cycle("red","white","blue") %>">
      <span style="background-color:<%= current_cycle %>"><%= item %></span>
    </div>
  <% end %>
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 454
454:       def current_cycle(name = "default")
455:         cycle = get_cycle(name)
456:         cycle.current_value unless cycle.nil?
457:       end
cycle(first_value, *values)

Creates a Cycle object whose to_s method cycles through elements of an array every time it is called. This can be used for example, to alternate classes for table rows. You can use named cycles to allow nesting in loops. Passing a Hash as the last parameter with a :name key will create a named cycle. The default name for a cycle without a +:name+ key is "default". You can manually reset a cycle by calling reset_cycle and passing the name of the cycle. The current cycle string can be obtained anytime using the current_cycle method.

Examples

  # Alternate CSS classes for even and odd numbers...
  @items = [1,2,3,4]
  <table>
  <% @items.each do |item| %>
    <tr class="<%= cycle("even", "odd") -%>">
      <td>item</td>
    </tr>
  <% end %>
  </table>

  # Cycle CSS classes for rows, and text colors for values within each row
  @items = x = [{:first => 'Robert', :middle => 'Daniel', :last => 'James'},
               {:first => 'Emily', :middle => 'Shannon', :maiden => 'Pike', :last => 'Hicks'},
              {:first => 'June', :middle => 'Dae', :last => 'Jones'}]
  <% @items.each do |item| %>
    <tr class="<%= cycle("even", "odd", :name => "row_class") -%>">
      <td>
        <% item.values.each do |value| %>
          <%# Create a named cycle "colors" %>
          <span style="color:<%= cycle("red", "green", "blue", :name => "colors") -%>">
            <%= value %>
          </span>
        <% end %>
        <% reset_cycle("colors") %>
      </td>
   </tr>
 <% end %>
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 426
426:       def cycle(first_value, *values)
427:         if (values.last.instance_of? Hash)
428:           params = values.pop
429:           name = params[:name]
430:         else
431:           name = "default"
432:         end
433:         values.unshift(first_value)
434: 
435:         cycle = get_cycle(name)
436:         if (cycle.nil? || cycle.values != values)
437:           cycle = set_cycle(name, Cycle.new(*values))
438:         end
439:         return cycle.to_s
440:       end
excerpt(text, phrase, *args)

Extracts an excerpt from text that matches the first instance of phrase. The :radius option expands the excerpt on each side of the first occurrence of phrase by the number of characters defined in :radius (which defaults to 100). If the excerpt radius overflows the beginning or end of the text, then the :omission option (which defaults to "…") will be prepended/appended accordingly. The resulting string will be stripped in any case. If the phrase isn‘t found, nil is returned.

Examples

  excerpt('This is an example', 'an', :radius => 5)
  # => ...s is an exam...

  excerpt('This is an example', 'is', :radius => 5)
  # => This is a...

  excerpt('This is an example', 'is')
  # => This is an example

  excerpt('This next thing is an example', 'ex', :radius => 2)
  # => ...next...

  excerpt('This is also an example', 'an', :radius => 8, :omission => '<chop> ')
  # => <chop> is also an example

You can still use excerpt with the old API that accepts the radius as its optional third and the ellipsis as its optional forth parameter:

  excerpt('This is an example', 'an', 5)                   # => ...s is an exam...
  excerpt('This is also an example', 'an', 8, '<chop> ')   # => <chop> is also an example
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 142
142:       def excerpt(text, phrase, *args)
143:         options = args.extract_options!
144:         unless args.empty?
145:           options[:radius] = args[0] || 100
146:           options[:omission] = args[1] || "..."
147:         end
148:         options.reverse_merge!(:radius => 100, :omission => "...")
149: 
150:         if text && phrase
151:           phrase = Regexp.escape(phrase)
152: 
153:           if found_pos = text.mb_chars =~ /(#{phrase})/i
154:             start_pos = [ found_pos - options[:radius], 0 ].max
155:             end_pos   = [ [ found_pos + phrase.mb_chars.length + options[:radius] - 1, 0].max, text.mb_chars.length ].min
156: 
157:             prefix  = start_pos > 0 ? options[:omission] : ""
158:             postfix = end_pos < text.mb_chars.length - 1 ? options[:omission] : ""
159: 
160:             prefix + text.mb_chars[start_pos..end_pos].strip + postfix
161:           else
162:             nil
163:           end
164:         end
165:       end
highlight(text, phrases, *args)

Highlights one or more phrases everywhere in text by inserting it into a :highlighter string. The highlighter can be specialized by passing :highlighter as a single-quoted string with \1 where the phrase is to be inserted (defaults to ’<strong class="highlight">\1</strong>’)

Examples

  highlight('You searched for: rails', 'rails')
  # => You searched for: <strong class="highlight">rails</strong>

  highlight('You searched for: ruby, rails, dhh', 'actionpack')
  # => You searched for: ruby, rails, dhh

  highlight('You searched for: rails', ['for', 'rails'], :highlighter => '<em>\1</em>')
  # => You searched <em>for</em>: <em>rails</em>

  highlight('You searched for: rails', 'rails', :highlighter => '<a href="search?q=\1">\1</a>')
  # => You searched for: <a href="search?q=rails">rails</a>

You can still use highlight with the old API that accepts the highlighter as its optional third parameter:

  highlight('You searched for: rails', 'rails', '<a href="search?q=\1">\1</a>')     # => You searched for: <a href="search?q=rails">rails</a>
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 100
100:       def highlight(text, phrases, *args)
101:         options = args.extract_options!
102:         unless args.empty?
103:           options[:highlighter] = args[0] || '<strong class="highlight">\1</strong>'
104:         end
105:         options.reverse_merge!(:highlighter => '<strong class="highlight">\1</strong>')
106: 
107:         if text.blank? || phrases.blank?
108:           text
109:         else
110:           match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
111:           text.gsub(/(#{match})(?!(?:[^<]*?)(?:["'])[^<>]*>)/i, options[:highlighter])
112:         end
113:       end
markdown(text)

Returns the text with all the Markdown codes turned into HTML tags. This method requires BlueCloth or another Markdown library to be installed..

Examples

  markdown("We are using __Markdown__ now!")
  # => "<p>We are using <strong>Markdown</strong> now!</p>"

  markdown("We like to _write_ `code`, not just _read_ it!")
  # => "<p>We like to <em>write</em> <code>code</code>, not just <em>read</em> it!</p>"

  markdown("The [Markdown website](http://daringfireball.net/projects/markdown/) has more information.")
  # => "<p>The <a href="http://daringfireball.net/projects/markdown/">Markdown website</a>
  #     has more information.</p>"

  markdown('![The ROR logo](http://rubyonrails.com/images/rails.png "Ruby on Rails")')
  # => '<p><img src="http://rubyonrails.com/images/rails.png" alt="The ROR logo" title="Ruby on Rails" /></p>'
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 299
299:       def markdown(text)
300:         text.blank? ? "" : Markdown.new(text).to_html
301:       end
pluralize(count, singular, plural = nil)

Attempts to pluralize the singular word unless count is 1. If plural is supplied, it will use that when count is > 1, otherwise it will use the Inflector to determine the plural form

Examples

  pluralize(1, 'person')
  # => 1 person

  pluralize(2, 'person')
  # => 2 people

  pluralize(3, 'person', 'users')
  # => 3 users

  pluralize(0, 'person')
  # => 0 people
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 183
183:       def pluralize(count, singular, plural = nil)
184:         "#{count || 0} " + ((count == 1 || count =~ /^1(\.0+)?$/) ? singular : (plural || singular.pluralize))
185:       end
reset_cycle(name = "default")

Resets a cycle so that it starts from the first element the next time it is called. Pass in name to reset a named cycle.

Example

  # Alternate CSS classes for even and odd numbers...
  @items = [[1,2,3,4], [5,6,3], [3,4,5,6,7,4]]
  <table>
  <% @items.each do |item| %>
    <tr class="<%= cycle("even", "odd") -%>">
        <% item.each do |value| %>
          <span style="color:<%= cycle("#333", "#666", "#999", :name => "colors") -%>">
            <%= value %>
          </span>
        <% end %>

        <% reset_cycle("colors") %>
    </tr>
  <% end %>
  </table>
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 478
478:       def reset_cycle(name = "default")
479:         cycle = get_cycle(name)
480:         cycle.reset unless cycle.nil?
481:       end
simple_format(text, html_options={})

Returns text transformed into HTML using simple formatting rules. Two or more consecutive newlines(\n\n) are considered as a paragraph and wrapped in <p> tags. One newline (\n) is considered as a linebreak and a <br /> tag is appended. This method does not remove the newlines from the text.

You can pass any HTML attributes into html_options. These will be added to all created paragraphs.

Examples

  my_text = "Here is some basic text...\n...with a line break."

  simple_format(my_text)
  # => "<p>Here is some basic text...\n<br />...with a line break.</p>"

  more_text = "We want to put a paragraph...\n\n...right there."

  simple_format(more_text)
  # => "<p>We want to put a paragraph...</p>\n\n<p>...right there.</p>"

  simple_format("Look ma! A class!", :class => 'description')
  # => "<p class='description'>Look ma! A class!</p>"
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 324
324:       def simple_format(text, html_options={})
325:         start_tag = tag('p', html_options, true)
326:         text = text.to_s.dup
327:         text.gsub!(/\r\n?/, "\n")                    # \r\n and \r -> \n
328:         text.gsub!(/\n\n+/, "</p>\n\n#{start_tag}")  # 2+ newline  -> paragraph
329:         text.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') # 1 newline   -> br
330:         text.insert 0, start_tag
331:         text.html_safe.safe_concat("</p>")
332:       end
textilize(text, *options)

Returns the text with all the Textile codes turned into HTML tags.

You can learn more about Textile‘s syntax at its website. This method is only available if RedCloth is available.

Examples

  textilize("*This is Textile!*  Rejoice!")
  # => "<p><strong>This is Textile!</strong>  Rejoice!</p>"

  textilize("I _love_ ROR(Ruby on Rails)!")
  # => "<p>I <em>love</em> <acronym title="Ruby on Rails">ROR</acronym>!</p>"

  textilize("h2. Textile makes markup -easy- simple!")
  # => "<h2>Textile makes markup <del>easy</del> simple!</h2>"

  textilize("Visit the Rails website "here":http://www.rubyonrails.org/.)
  # => "<p>Visit the Rails website <a href="http://www.rubyonrails.org/">here</a>.</p>"

  textilize("This is worded <strong>strongly</strong>")
  # => "<p>This is worded <strong>strongly</strong></p>"

  textilize("This is worded <strong>strongly</strong>", :filter_html)
  # => "<p>This is worded &lt;strong&gt;strongly&lt;/strong&gt;</p>"
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 245
245:       def textilize(text, *options)
246:         options ||= [:hard_breaks]
247: 
248:         if text.blank?
249:           ""
250:         else
251:           textilized = RedCloth.new(text, options)
252:           textilized.to_html
253:         end
254:       end
textilize_without_paragraph(text)

Returns the text with all the Textile codes turned into HTML tags, but without the bounding <p> tag that RedCloth adds.

You can learn more about Textile‘s syntax at its website. This method is requires RedCloth to be available.

Examples

  textilize_without_paragraph("*This is Textile!*  Rejoice!")
  # => "<strong>This is Textile!</strong>  Rejoice!"

  textilize_without_paragraph("I _love_ ROR(Ruby on Rails)!")
  # => "I <em>love</em> <acronym title="Ruby on Rails">ROR</acronym>!"

  textilize_without_paragraph("h2. Textile makes markup -easy- simple!")
  # => "<h2>Textile makes markup <del>easy</del> simple!</h2>"

  textilize_without_paragraph("Visit the Rails website "here":http://www.rubyonrails.org/.)
  # => "Visit the Rails website <a href="http://www.rubyonrails.org/">here</a>."
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 275
275:       def textilize_without_paragraph(text)
276:         textiled = textilize(text)
277:         if textiled[0..2] == "<p>" then textiled = textiled[3..-1] end
278:         if textiled[-4..-1] == "</p>" then textiled = textiled[0..-5] end
279:         return textiled
280:       end
truncate(text, *args)

Truncates a given text after a given :length if text is longer than :length (defaults to 30). The last characters will be replaced with the :omission (defaults to "…") for a total length not exceeding :length.

Examples

  truncate("Once upon a time in a world far far away")
  # => Once upon a time in a world...

  truncate("Once upon a time in a world far far away", :length => 14)
  # => Once upon a...

  truncate("And they found that many people were sleeping better.", :length => 25, "(clipped)")
  # => And they found t(clipped)

  truncate("And they found that many people were sleeping better.", :omission => "... (continued)", :length => 25)
  # => And they f... (continued)

You can still use truncate with the old API that accepts the length as its optional second and the ellipsis as its optional third parameter:

  truncate("Once upon a time in a world far far away", 14)
  # => Once upon a...

  truncate("And they found that many people were sleeping better.", 25, "... (continued)")
  # => And they f... (continued)
    # File actionpack/lib/action_view/helpers/text_helper.rb, line 61
61:       def truncate(text, *args)
62:         options = args.extract_options!
63:         unless args.empty?
64:           ActiveSupport::Deprecation.warn('truncate takes an option hash instead of separate ' +
65:             'length and omission arguments', caller)
66: 
67:           options[:length] = args[0] || 30
68:           options[:omission] = args[1] || "..."
69:         end
70:         options.reverse_merge!(:length => 30, :omission => "...")
71: 
72:         if text
73:           l = options[:length] - options[:omission].mb_chars.length
74:           chars = text.mb_chars
75:           (chars.length > options[:length] ? chars[0...l] + options[:omission] : text).to_s
76:         end
77:       end
word_wrap(text, *args)

Wraps the text into lines no longer than line_width width. This method breaks on the first whitespace character that does not exceed line_width (which is 80 by default).

Examples

  word_wrap('Once upon a time')
  # => Once upon a time

  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...')
  # => 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...

  word_wrap('Once upon a time', :line_width => 8)
  # => Once upon\na time

  word_wrap('Once upon a time', :line_width => 1)
  # => Once\nupon\na\ntime

You can still use word_wrap with the old API that accepts the line_width as its optional second parameter:

  word_wrap('Once upon a time', 8)     # => Once upon\na time
     # File actionpack/lib/action_view/helpers/text_helper.rb, line 208
208:       def word_wrap(text, *args)
209:         options = args.extract_options!
210:         unless args.blank?
211:           options[:line_width] = args[0] || 80
212:         end
213:         options.reverse_merge!(:line_width => 80)
214: 
215:         text.split("\n").collect do |line|
216:           line.length > options[:line_width] ? line.gsub(/(.{1,#{options[:line_width]}})(\s+|$)/, "\\1\n").strip : line
217:         end * "\n"
218:       end