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Action View Tag Helpers ↑

Provides methods to generate HTML tags programmatically both as a modern HTML5 compliant builder style and legacy XHTML compliant tags.

Namespace
Methods
B
C
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T
Included Modules

Constants

ARIA_PREFIXES = ["aria", :aria].to_set.freeze
 
BOOLEAN_ATTRIBUTES = %w(allowfullscreen allowpaymentrequest async autofocus autoplay checked compact controls declare default defaultchecked defaultmuted defaultselected defer disabled enabled formnovalidate hidden indeterminate inert ismap itemscope loop multiple muted nohref nomodule noresize noshade novalidate nowrap open pauseonexit playsinline readonly required reversed scoped seamless selected sortable truespeed typemustmatch visible).to_set
 
CLASS_PREFIXES = ["class", :class].to_set.freeze
 
DATA_PREFIXES = ["data", :data].to_set.freeze
 
PRE_CONTENT_STRINGS = Hash.new { "" }
 
TAG_TYPES = {}
 

Class Public methods

build_tag_values(*args)

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1771
def build_tag_values(*args)
  tag_values = []

  args.each do |tag_value|
    case tag_value
    when Hash
      tag_value.each do |key, val|
        tag_values << key.to_s if val && key.present?
      end
    when Array
      tag_values.concat build_tag_values(*tag_value)
    else
      tag_values << tag_value.to_s if tag_value.present?
    end
  end

  tag_values
end

ensure_valid_html5_tag_name(name)

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1766
def ensure_valid_html5_tag_name(name)
  raise ArgumentError, "Invalid HTML5 tag name: #{name.inspect}" unless /\A[a-zA-Z][^\s\/>]*\z/.match?(name)
end

Instance Public 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 ]]>.

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]]>

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1749
def cdata_section(content)
  splitted = content.to_s.gsub(/\]\]>/, "]]]]><![CDATA[>")
  "<![CDATA[#{splitted}]]>".html_safe
end

class_names(*args)

Alias for: token_list

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 escaping. Note: this is legacy syntax, see tag method description for details.

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(:div, "Hello world!", class: ["strong", { highlight: current_user.admin? }])
 # => <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>

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1707
def content_tag(name, content_or_options_with_block = nil, options = nil, escape = true, &block)
  ensure_valid_html5_tag_name(name)

  if block_given?
    options = content_or_options_with_block if content_or_options_with_block.is_a?(Hash)
    tag_builder.content_tag_string(name, capture(&block), options, escape)
  else
    tag_builder.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.

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

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

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1761
def escape_once(html)
  ERB::Util.html_escape_once(html)
end

tag(name = nil, options = nil, open = false, escape = true)

Modern syntax ↑

Builds HTML5 compliant tags with a tag proxy. Every tag can be built with:

tag.<tag name>(optional content, options)

where tag name can be e.g. br, div, section, article, or any tag really.

Returns an instance of TagBuilder when invoked without positional, keyword, or block arguments.

Legacy syntax ↑

Returns an HTML tag.

The following format is for legacy syntax support. It will be deprecated in future versions of Rails.

tag(name, options = nil, open = false, escape = true)

It 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.

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;]" />

tag("div", class: { highlight: current_user.admin? })
# => <div class="highlight" />

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1670
def tag(name = nil, options = nil, open = false, escape = true)
  if name.nil?
    tag_builder
  else
    ensure_valid_html5_tag_name(name)
    "<#{name}#{tag_builder.tag_options(options, escape) if options}#{open ? ">" : " />"}".html_safe
  end
end

token_list(*args)

Returns a string of tokens built from args.

Examples ↑

token_list("foo", "bar")
 # => "foo bar"
token_list("foo", "foo bar")
 # => "foo bar"
token_list({ foo: true, bar: false })
 # => "foo"
token_list(nil, false, 123, "", "foo", { bar: true })
 # => "123 foo bar"
Also aliased as: class_names

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/tag_helper.rb, line 1729
def token_list(*args)
  tokens = build_tag_values(*args).flat_map { |value| CGI.unescape_html(value.to_s).split(/\s+/) }.uniq

  safe_join(tokens, " ")
end