module ActionView::Helpers::TextHelper - actionview-4.2.3 Documentation

# module ActionView::Helpers::TextHelper

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_format` method:

    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>"

### Public Instance Methods

concat(string) click to toggle source

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.

    <%
        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 lib/action_view/helpers/text_helper.rb, line 52
    def concat(string)
      output_buffer << string
    end

current_cycle(name = "default") click to toggle source

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.

    # 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 lib/action_view/helpers/text_helper.rb, line 359
    def current_cycle(name = "default")
      cycle = get_cycle(name)
      cycle.current_value if cycle
    end

cycle(first_value, *values) click to toggle source

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.

     # 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 lib/action_view/helpers/text_helper.rb, line 335
    def cycle(first_value, *values)
      options = values.extract_options!
      name = options.fetch(:name, 'default')

      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, options = {}) click to toggle source

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. Use the `:separator` option to choose the delimitation. The resulting string will be stripped in any case. If the `phrase` isn't found, nil is returned.

    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

    excerpt('This is a very beautiful morning', 'very', separator: ' ', radius: 1)
    # => ...a very beautiful...

    # File lib/action_view/helpers/text_helper.rb, line 168
    def excerpt(text, phrase, options = {})
      return unless text && phrase

      separator = options.fetch(:separator, nil) || ""
      case phrase
      when Regexp
        regex = phrase
      else
        regex = /#{Regexp.escape(phrase)}/i
      end

      return unless matches = text.match(regex)
      phrase = matches[0]

      unless separator.empty?
        text.split(separator).each do |value|
          if value.match(regex)
            regex = phrase = value
            break
          end
        end
      end

      first_part, second_part = text.split(phrase, 2)

      prefix, first_part   = cut_excerpt_part(:first, first_part, separator, options)
      postfix, second_part = cut_excerpt_part(:second, second_part, separator, options)

      affix = [first_part, separator, phrase, separator, second_part].join.strip
      [prefix, affix, postfix].join
    end

highlight(text, phrases, options = {}) { |found| ... } click to toggle source

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 '<mark>1</mark>') or passing a block that receives each matched term.

    highlight('You searched for: rails', 'rails')
    # => You searched for: <mark>rails</mark>

    highlight('You searched for: rails', /for|rails/)
    # => You searched <mark>for</mark>: <mark>rails</mark>

    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>

    highlight('You searched for: rails', 'rails') { |match| link_to(search_path(q: match, match)) }
    # => You searched for: <a href="search?q=rails">rails</a>

    # File lib/action_view/helpers/text_helper.rb, line 125
    def highlight(text, phrases, options = {})
      text = sanitize(text) if options.fetch(:sanitize, true)

      if text.blank? || phrases.blank?
        text || ""
      else
        match = Array(phrases).map do |p|
          Regexp === p ? p.to_s : Regexp.escape(p)
        end.join('|')

        if block_given?
          text.gsub(/(#{match})(?![^<]*?>)/i) { |found| yield found }
        else
          highlighter = options.fetch(:highlighter, '<mark>\1</mark>')
          text.gsub(/(#{match})(?![^<]*?>)/i, highlighter)
        end
      end.html_safe
    end

pluralize(count, singular, plural = nil) click to toggle source

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.

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

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

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

    pluralize(0, 'person')
    # => 0 people

    # File lib/action_view/helpers/text_helper.rb, line 215
    def pluralize(count, singular, plural = nil)
      word = if (count == 1 || count =~ /^1(\.0+)?$/)
        singular
      else
        plural || singular.pluralize
      end

      "#{count || 0} #{word}"
    end

reset_cycle(name = "default") click to toggle source

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.

    # 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 lib/action_view/helpers/text_helper.rb, line 382
    def reset_cycle(name = "default")
      cycle = get_cycle(name)
      cycle.reset if cycle
    end

safe_concat(string) click to toggle source

    # File lib/action_view/helpers/text_helper.rb, line 56
    def safe_concat(string)
      output_buffer.respond_to?(:safe_concat) ? output_buffer.safe_concat(string) : concat(string)
    end

simple_format(text, html_options = {}, options = {}) click to toggle source

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.

#### Options¶ ↑

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

- `:wrapper_tag` - String representing the wrapper tag, defaults to `"p"`

#### 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>"

    simple_format(my_text, {}, wrapper_tag: "div")
    # => "<div>Here is some basic text...\n<br />...with a line break.</div>"

    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("<blink>Unblinkable.</blink>")
    # => "<p>Unblinkable.</p>"

    simple_format("<blink>Blinkable!</blink> It's true.", {}, sanitize: false)
    # => "<p><blink>Blinkable!</blink> It's true.</p>"

    # File lib/action_view/helpers/text_helper.rb, line 283
    def simple_format(text, html_options = {}, options = {})
      wrapper_tag = options.fetch(:wrapper_tag, :p)

      text = sanitize(text) if options.fetch(:sanitize, true)
      paragraphs = split_paragraphs(text)

      if paragraphs.empty?
        content_tag(wrapper_tag, nil, html_options)
      else
        paragraphs.map! { |paragraph|
          content_tag(wrapper_tag, raw(paragraph), html_options)
        }.join("\n\n").html_safe
      end
    end

truncate(text, options = {}, &block) click to toggle source

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`.

Pass a `:separator` to truncate `text` at a natural break.

Pass a block if you want to show extra content when the text is truncated.

The result is marked as HTML-safe, but it is escaped by default, unless `:escape` is `false`. Care should be taken if `text` contains HTML tags or entities, because truncation may produce invalid HTML (such as unbalanced or incomplete tags).

    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>")
    # => "&lt;p&gt;Once upon a time in a wo..."

    truncate("<p>Once upon a time in a world far far away</p>", escape: false)
    # => "<p>Once upon a time in a wo..."

    truncate("Once upon a time in a world far far away") { link_to "Continue", "#" }
    # => "Once upon a time in a wo...<a href="#">Continue</a>"

    # File lib/action_view/helpers/text_helper.rb, line 92
    def truncate(text, options = {}, &block)
      if text
        length  = options.fetch(:length, 30)

        content = text.truncate(length, options)
        content = options[:escape] == false ? content.html_safe : ERB::Util.html_escape(content)
        content << capture(&block) if block_given? && text.length > length
        content
      end
    end

word_wrap(text, options = {}) click to toggle source

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).

    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\na successor to the throne turned out to be more trouble than anyone could have\nimagined...

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

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

    # File lib/action_view/helpers/text_helper.rb, line 240
    def word_wrap(text, options = {})
      line_width = options.fetch(:line_width, 80)

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

### Private Instance Methods

cut_excerpt_part(part_position, part, separator, options) click to toggle source

    # File lib/action_view/helpers/text_helper.rb, line 446
    def cut_excerpt_part(part_position, part, separator, options)
      return "", "" unless part

      radius   = options.fetch(:radius, 100)
      omission = options.fetch(:omission, "...")

      part = part.split(separator)
      part.delete("")
      affix = part.size > radius ? omission : ""

      part = if part_position == :first
        drop_index = [part.length - radius, 0].max
        part.drop(drop_index)
      else
        part.first(radius)
      end

      return affix, part.join(separator)
    end

get_cycle(name) click to toggle source

The cycle helpers need to store the cycles in a place that is guaranteed to be reset every time a page is rendered, so it uses an instance variable of ActionView::Base.

    # File lib/action_view/helpers/text_helper.rb, line 428
    def get_cycle(name)
      @_cycles = Hash.new unless defined?(@_cycles)
      return @_cycles[name]
    end

set_cycle(name, cycle_object) click to toggle source

    # File lib/action_view/helpers/text_helper.rb, line 433
    def set_cycle(name, cycle_object)
      @_cycles = Hash.new unless defined?(@_cycles)
      @_cycles[name] = cycle_object
    end

split_paragraphs(text) click to toggle source

    # File lib/action_view/helpers/text_helper.rb, line 438
    def split_paragraphs(text)
      return [] if text.blank?

      text.to_str.gsub(/\r\n?/, "\n").split(/\n\n+/).map! do |t|
        t.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') || t
      end
    end