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 Action View making them callable within your template files.

Sanitization

Most text helpers by default sanitize the given content, but do not escape it. This means HTML tags will appear in the page but all malicious code will be removed. Let's look at some examples using the simple_formatmethod:

simple_format('<a href="http://example.com/">Example</a>')
# => "<p><a href=\"http://example.com/\">Example</a></p>"

simple_format('<a href="javascript:alert(\'no!\')">Example</a>')
# => "<p><a>Example</a></p>"

If you want to escape all content, you should invoke the h method before calling the text helper.

simple_format h('<a href="http://example.com/">Example</a>')
# => "<p>&lt;a href=\"http://example.com/\"&gt;Example&lt;/a&gt;</p>"
Methods
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Included Modules
Instance Public methods
concat(string)

The preferred method of outputting text in your views is to use the <%= “text” %> eRuby syntax. The regular putsand 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
      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 51
def concat(string)
  output_buffer << string
end
current_cycle(name = "default")

Returns the current cycle string after a cycle has been started. Useful for complex table highlighting 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 345
def current_cycle(name = "default")
  cycle = get_cycle(name)
  cycle.current_value if cycle
end
cycle(first_value, *values)

Creates a Cycle object whose to_smethod 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 :namekey 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("odd", "even") -%>">
     <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("odd", "even", :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 317
def cycle(first_value, *values)
  if (values.last.instance_of? Hash)
    params = values.pop
    name = params[:name]
  else
    name = "default"
  end
  values.unshift(first_value)

  cycle = get_cycle(name)
  unless cycle && cycle.values == values
    cycle = set_cycle(name, Cycle.new(*values))
  end
  cycle.to_s
end
excerpt(text, phrase, *args)

Extracts an excerpt from textthat matches the first instance of phrase. The :radiusoption expands the excerpt on each side of the first occurrence of phraseby 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 :omissionoption (which defaults to “…”) will be prepended/appended accordingly. The resulting string will be stripped in any case. If the phraseisn'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 excerptwith the old API that accepts the radiusas its optional third and the ellipsisas 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 157
def excerpt(text, phrase, *args)
  return unless text && phrase

  options = args.extract_options!
  unless args.empty?
    ActiveSupport::Deprecation.warn "Calling excerpt with radius and omission as arguments is deprecated. "            "Please call with :radius => #{args[0]}#{", :omission => '#{args[1]}'" if args[1]} instead.", caller

    options[:radius] = args[0] || 100
    options[:omission] = args[1] || "..."
  end
  options.reverse_merge!(:radius => 100, :omission => "...")

  phrase = Regexp.escape(phrase)
  return unless found_pos = text.mb_chars =~ /(#{phrase})/i

  start_pos = [ found_pos - options[:radius], 0 ].max
  end_pos   = [ [ found_pos + phrase.mb_chars.length + options[:radius] - 1, 0].max, text.mb_chars.length ].min

  prefix  = start_pos > 0 ? options[:omission] : ""
  postfix = end_pos < text.mb_chars.length - 1 ? options[:omission] : ""

  prefix + text.mb_chars[start_pos..end_pos].strip + postfix
end
highlight(text, phrases, *args)

Highlights one or more phraseseverywhere in text by inserting it into a :highlighterstring. The highlighter can be specialized by passing :highlighteras 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 highlightwith the old API that accepts the highlighteras 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 111
def highlight(text, phrases, *args)
  options = args.extract_options!
  unless args.empty?
    ActiveSupport::Deprecation.warn "Calling highlight with a highlighter as an argument is deprecated. "            "Please call with :highlighter => '#{args[0]}' instead.", caller

    options[:highlighter] = args[0] || '<strong class="highlight">\1</strong>'
  end
  options.reverse_merge!(:highlighter => '<strong class="highlight">\1</strong>')

  text = sanitize(text) unless options[:sanitize] == false
  if text.blank? || phrases.blank?
    text
  else
    match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
    text.gsub(/(#{match})(?![^<]*?>)/i, options[:highlighter])
  end.html_safe
end
pluralize(count, singular, plural = nil)

Attempts to pluralize the singularword unless countis 1. If pluralis 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 198
def pluralize(count, singular, plural = nil)
  "#{count || 0} " + ((count == 1 || count =~ /^1(\.0+)?$/) ? singular : (plural || singular.pluralize))
end
reset_cycle(name = "default")

Resets a cycle so that it starts from the first element the next time it is called. Pass in nameto 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 369
def reset_cycle(name = "default")
  cycle = get_cycle(name)
  cycle.reset if cycle
end
safe_concat(string)
# File actionpack/lib/action_view/helpers/text_helper.rb, line 55
def safe_concat(string)
  output_buffer.respond_to?(:safe_concat) ? output_buffer.safe_concat(string) : concat(string)
end
simple_format(text, html_options={}, options={})

Returns texttransformed 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.

Options

  • :sanitize- If false, does not sanitize text.

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>"

simple_format("<span>I'm allowed!</span> It's true.", {}, :sanitize => false)
# => "<p><span>I'm allowed!</span> It's true.</p>"
# File actionpack/lib/action_view/helpers/text_helper.rb, line 266
def simple_format(text, html_options={}, options={})
  text = '' if text.nil?
  text = text.dup
  start_tag = tag('p', html_options, true)
  text = sanitize(text) unless options[:sanitize] == false
  text = text.to_str
  text.gsub!(/\r\n?/, "\n")                    # \r\n and \r -> \n
  text.gsub!(/\n\n+/, "</p>\n\n#{start_tag}")  # 2+ newline  -> paragraph
  text.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') # 1 newline   -> br
  text.insert 0, start_tag
  text.html_safe.safe_concat("</p>")
end
truncate(text, options = {})

Truncates a given textafter a given :lengthif textis longer than :length(defaults to 30). The last characters will be replaced with the :omission(defaults to “…”) for a total length not exceeding :length.

Pass a :separatorto truncate textat a natural break.

The result is not marked as HTML-safe, so will be subject to the default escaping when used in views, unless wrapped by raw(). Care should be taken if textcontains HTML tags or entities, because truncation may produce invalid HTML (such as unbalanced or incomplete tags).

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 => 17)
# => "Once upon a ti..."

truncate("Once upon a time in a world far far away", :length => 17, :separator => ' ')
# => "Once upon a..."

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

truncate("<p>Once upon a time in a world far far away</p>")
# => "<p>Once upon a time in a wo..."
# File actionpack/lib/action_view/helpers/text_helper.rb, line 85
def truncate(text, options = {})
  options.reverse_merge!(:length => 30)
  text.truncate(options.delete(:length), options) if text
end
word_wrap(text, *args)

Wraps the textinto lines no longer than line_widthwidth. 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_wrapwith the old API that accepts the line_widthas 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 223
def word_wrap(text, *args)
  options = args.extract_options!
  unless args.blank?
    ActiveSupport::Deprecation.warn "Calling word_wrap with line_width as an argument is deprecated. "            "Please call with :line_width => #{args[0]} instead.", caller

    options[:line_width] = args[0] || 80
  end
  options.reverse_merge!(:line_width => 80)

  text.split("\n").collect do |line|
    line.length > options[:line_width] ? line.gsub(/(.{1,#{options[:line_width]}})(\s+|$)/, "\\1\n").strip : line
  end * "\n"
end