Provides methods to generate HTML tags programmatically when you can’t use a Builder. By default, they output XHTML compliant tags.

Methods
Included Modules
Constants
BOOLEAN_ATTRIBUTES = %w(disabled readonly multiple checked autobuffer autoplay controls loop selected hidden scoped async defer reversed ismap seemless muted required autofocus novalidate formnovalidate open).to_set
Public Instance methods
cdata_section(content)

Returns a CDATA section with the given content. CDATA sections are used to escape blocks of text containing characters which would otherwise be recognized as markup. CDATA sections begin with the string <![CDATA[ and end with (and may not contain) the string ]]>.

Examples

cdata_section("<hello world>")
# => <![CDATA[<hello world>]]>

cdata_section(File.read("hello_world.txt"))
# => <![CDATA[<hello from a text file]]>

[ show source ]

  # File actionpack/lib/action_view/helpers/tag_helper.rb, line 94
def cdata_section(content)
  "<![CDATA[#{content}]]>".html_safe
end
content_tag(name, content_or_options_with_block = nil, options = nil, escape = true, &block)

Returns an HTML block tag of type name surrounding the content. Add HTML attributes by passing an attributes hash to options. Instead of passing the content as an argument, you can also use a block in which case, you pass your options as the second parameter. Set escape to false to disable attribute value escaping.

Options

The options hash is used with attributes with no value like (disabled and readonly), which you can give a value of true in the options hash. You can use symbols or strings for the attribute names.

Examples

content_tag(:p, "Hello world!")
 # => <p>Hello world!</p>
content_tag(:div, content_tag(:p, "Hello world!"), :class => "strong")
 # => <div class="strong"><p>Hello world!</p></div>
content_tag("select", options, :multiple => true)
 # => <select multiple="multiple">...options...</select>

<%= content_tag :div, :class => "strong" do -%>
  Hello world!
<% end -%>
 # => <div class="strong">Hello world!</div>

[ show source ]

  # File actionpack/lib/action_view/helpers/tag_helper.rb, line 74
def content_tag(name, content_or_options_with_block = nil, options = nil, escape = true, &block)
  if block_given?
    options = content_or_options_with_block if content_or_options_with_block.is_a?(Hash)
    content_tag_string(name, capture(&block), options, escape)
  else
    content_tag_string(name, content_or_options_with_block, options, escape)
  end
end
escape_once(html)

Returns an escaped version of html without affecting existing escaped entities.

Examples

escape_once("1 < 2 &amp; 3")
# => "1 &lt; 2 &amp; 3"

escape_once("&lt;&lt; Accept & Checkout")
# => "&lt;&lt; Accept &amp; Checkout"

[ show source ]

  # File actionpack/lib/action_view/helpers/tag_helper.rb, line 106
def escape_once(html)
  ActiveSupport::Multibyte.clean(html.to_s).gsub(/[\"><]|&(?!([a-zA-Z]+|(#\d+));)/) { |special| ERB::Util::HTML_ESCAPE[special] }
end
tag(name, options = nil, open = false, escape = true)

Returns an empty HTML tag of type name which by default is XHTML compliant. Set open to true to create an open tag compatible with HTML 4.0 and below. Add HTML attributes by passing an attributes hash to options. Set escape to false to disable attribute value escaping.

Options

The options hash is used with attributes with no value like (disabled and readonly), which you can give a value of true in the options hash. You can use symbols or strings for the attribute names.

Examples

tag("br")
# => <br />

tag("br", nil, true)
# => <br>

tag("input", { :type => 'text', :disabled => true })
# => <input type="text" disabled="disabled" />

tag("img", { :src => "open & shut.png" })
# => <img src="open &amp; shut.png" />

tag("img", { :src => "open &amp; shut.png" }, false, false)
# => <img src="open &amp; shut.png" />

[ show source ]

  # File actionpack/lib/action_view/helpers/tag_helper.rb, line 47
def tag(name, options = nil, open = false, escape = true)
  "<#{name}#{tag_options(options, escape) if options}#{open ? ">" : " />"}".html_safe
end