Module: ActionView::Helpers::TagHelper

Extended by:
ActiveSupport::Concern
Includes:
CaptureHelper
Included in:
ActionView::Helpers, AssetTagHelper, DateTimeSelector, DebugHelper, ActionView::Helpers::Tags::Base, TextHelper, UrlHelper
Defined in:
actionview/lib/action_view/helpers/tag_helper.rb

Overview

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

Constant Summary

BOOLEAN_ATTRIBUTES =
%w(disabled readonly multiple checked autobuffer
autoplay controls loop selected hidden scoped async
defer reversed ismap seamless muted required
autofocus novalidate formnovalidate open pubdate
itemscope allowfullscreen default inert sortable
truespeed typemustmatch).to_set
PRE_CONTENT_STRINGS =
{
  :textarea => "\n"
}

Instance Method Summary (collapse)

Methods included from ActiveSupport::Concern

append_features, class_methods, extended, included

Methods included from CaptureHelper

#capture, #content_for, #content_for?, #flush_output_buffer, #provide, #with_output_buffer

Instance Method Details

- (Object) 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 ]]>.

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

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

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


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# File 'actionview/lib/action_view/helpers/tag_helper.rb', line 122

def cdata_section(content)
  splitted = content.to_s.gsub(']]>', ']]]]><![CDATA[>')
  "<![CDATA[#{splitted}]]>".html_safe
end

- (Object) 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 can be 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(:div, "Hello world!", class: ["strong", "highlight"])
 # => <div class="strong highlight">Hello world!</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>


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# File 'actionview/lib/action_view/helpers/tag_helper.rb', line 100

def (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)
    (name, capture(&block), options, escape)
  else
    (name, content_or_options_with_block, options, escape)
  end
end

- (Object) escape_once(html)

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

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

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


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# File 'actionview/lib/action_view/helpers/tag_helper.rb', line 134

def escape_once(html)
  ERB::Util.html_escape_once(html)
end

- (Object) 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

You can use symbols or strings for the attribute names.

Use true with boolean attributes that can render with no value, like disabled and readonly.

HTML5 data-* attributes can be set with a single data key pointing to a hash of sub-attributes.

To play nicely with JavaScript conventions sub-attributes are dasherized. For example, a key user_id would render as data-user-id and thus accessed as dataset.userId.

Values are encoded to JSON, with the exception of strings, symbols and BigDecimals. This may come in handy when using jQuery's HTML5-aware .data() from 1.4.3.

Examples

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

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

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

tag("input", type: 'text', class: ["strong", "highlight"])
# => <input class="strong highlight" type="text" />

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" />

tag("div", data: {name: 'Stephen', city_state: %w(Chicago IL)})
# => <div data-name="Stephen" data-city-state="[&quot;Chicago&quot;,&quot;IL&quot;]" />


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# File 'actionview/lib/action_view/helpers/tag_helper.rb', line 71

def tag(name, options = nil, open = false, escape = true)
  "<#{name}#{tag_options(options, escape) if options}#{open ? ">" : " />"}".html_safe
end