Module: ActionView::Helpers::TextHelper

Included in:
ActionView::Helpers
Defined in:
lib/action_view/helpers/text_helper.rb

Overview

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.

Defined Under Namespace

Classes: Cycle

Constant Summary collapse

%r{
 (                          # leading text
   <\w+.*?>|                # leading HTML tag, or
   [^=!:'"/]|               # leading punctuation, or
   ^                        # beginning of line
 )
 (
   (?:https?://)|           # protocol spec, or
   (?:www\.)                # www.*
 )
 (
   [-\w]+                   # subdomain or domain
   (?:\.[-\w]+)*            # remaining subdomains or domain
   (?::\d+)?                # port
   (?:/(?:[~\w\[email protected]%=\(\)-]|(?:[,.;:'][^\s$]))*)* # path
   (?:\?[\w\[email protected]%&=.;:-]+)?     # query string
   (?:\#[\w\-]*)?           # trailing anchor
 )
 ([[:punct:]]|<|$|)       # trailing text
}x

Instance Method Summary collapse

Instance Method Details

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 [email protected]")
# => "Go to <a href=\"http://www.rubyonrails.org\">http://www.rubyonrails.org</a> and
#     say hello to <a href=\"mailto:[email protected]\">[email protected]</a>"

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

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

post_body = "Welcome to my new blog at http://www.myblog.com/.  Please e-mail me at [email protected]"
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:[email protected]\">[email protected]</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 [email protected]"
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 [email protected]"

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:[email protected]\">[email protected]</a>."

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# File 'lib/action_view/helpers/text_helper.rb', line 384

def auto_link(text, *args, &block)#link = :all, href_options = {}, &block)
  return '' if text.blank?

  options = args.size == 2 ? {} : args.extract_options! # this is necessary because the old auto_link API has a Hash as its last parameter
  unless args.empty?
    options[:link] = args[0] || :all
    options[:html] = args[1] || {}
  end
  options.reverse_merge!(:link => :all, :html => {})

  case options[:link].to_sym
    when :all                         then auto_link_email_addresses(auto_link_urls(text, options[:html], &block), &block)
    when :email_addresses             then auto_link_email_addresses(text, &block)
    when :urls                        then auto_link_urls(text, options[:html], &block)
  end
end

#concat(string, unused_binding = nil) ⇒ Object

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
%>

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# File 'lib/action_view/helpers/text_helper.rb', line 37

def concat(string, unused_binding = nil)
  if unused_binding
    ActiveSupport::Deprecation.warn("The binding argument of #concat is no longer needed.  Please remove it from your views and helpers.", caller)
  end

  output_buffer << string
end

#current_cycle(name = "default") ⇒ Object

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 %>

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# File 'lib/action_view/helpers/text_helper.rb', line 467

def current_cycle(name = "default")
  cycle = get_cycle(name)
  cycle.current_value unless cycle.nil?
end

#cycle(first_value, *values) ⇒ Object

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 %>

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# File 'lib/action_view/helpers/text_helper.rb', line 439

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)
  if (cycle.nil? || cycle.values != values)
    cycle = set_cycle(name, Cycle.new(*values))
  end
  return cycle.to_s
end

#excerpt(text, phrase, *args) ⇒ Object

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

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# File 'lib/action_view/helpers/text_helper.rb', line 151

def excerpt(text, phrase, *args)
  options = args.extract_options!
  unless args.empty?
    options[:radius] = args[0] || 100
    options[:omission] = args[1] || "..."
  end
  options.reverse_merge!(:radius => 100, :omission => "...")

  if text && phrase
    phrase = Regexp.escape(phrase)

    if 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
    else
      nil
    end
  end
end

#highlight(text, phrases, *args) ⇒ Object

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>

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# File 'lib/action_view/helpers/text_helper.rb', line 109

def highlight(text, phrases, *args)
  options = args.extract_options!
  unless args.empty?
    options[:highlighter] = args[0] || '<strong class="highlight">\1</strong>'
  end
  options.reverse_merge!(:highlighter => '<strong class="highlight">\1</strong>')

  if text.blank? || phrases.blank?
    text
  else
    match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
    text.gsub(/(#{match})/i, options[:highlighter])
  end
end

#pluralize(count, singular, plural = nil) ⇒ Object

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

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# File 'lib/action_view/helpers/text_helper.rb', line 192

def pluralize(count, singular, plural = nil)
  "#{count || 0} " + ((count == 1 || count == '1') ? singular : (plural || singular.pluralize))
end

#reset_cycle(name = "default") ⇒ Object

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>

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# File 'lib/action_view/helpers/text_helper.rb', line 491

def reset_cycle(name = "default")
  cycle = get_cycle(name)
  cycle.reset unless cycle.nil?
end

#simple_format(text, html_options = {}) ⇒ Object

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>"

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# File 'lib/action_view/helpers/text_helper.rb', line 337

def simple_format(text, html_options={})
  start_tag = tag('p', html_options, true)
  text = text.to_s.dup
  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 << "</p>"
end

#truncate(text, *args) ⇒ Object

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 “…”).

Examples

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

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 that many (clipped)

truncate("And they found that many people were sleeping better.", :omission => "... (continued)", :length => 15)
# => And they found... (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 time in a world f...

truncate("And they found that many people were sleeping better.", 15, "... (continued)")
# => And they found... (continued)

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# File 'lib/action_view/helpers/text_helper.rb', line 70

def truncate(text, *args)
  options = args.extract_options!
  unless args.empty?
    ActiveSupport::Deprecation.warn('truncate takes an option hash instead of separate ' +
      'length and omission arguments', caller)

    options[:length] = args[0] || 30
    options[:omission] = args[1] || "..."
  end
  options.reverse_merge!(:length => 30, :omission => "...")

  if text
    l = options[:length] - options[:omission].mb_chars.length
    chars = text.mb_chars
    (chars.length > options[:length] ? chars[0...l] + options[:omission] : text).to_s
  end
end

#word_wrap(text, *args) ⇒ Object

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

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# File 'lib/action_view/helpers/text_helper.rb', line 217

def word_wrap(text, *args)
  options = args.extract_options!
  unless args.blank?
    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