module ActionView::Helpers::TagHelper
Provides methods to generate HTML tags programmatically when you can't use a Builder. By default, they output XHTML compliant tags.
Constants
- BOOLEAN_ATTRIBUTES
- PRE_CONTENT_STRINGS
- TAG_PREFIXES
Public Instance Methods
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]]>
# File lib/action_view/helpers/tag_helper.rb, line 125 def cdata_section(content) splitted = content.to_s.gsub(/\]\]\>/, ']]]]><![CDATA[>') "<![CDATA[#{splitted}]]>".html_safe end
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>
# File lib/action_view/helpers/tag_helper.rb, line 103 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
Returns an escaped version of html
without affecting existing
escaped entities.
escape_once("1 < 2 & 3") # => "1 < 2 & 3" escape_once("<< Accept & Checkout") # => "<< Accept & Checkout"
# File lib/action_view/helpers/tag_helper.rb, line 137 def escape_once(html) ERB::Util.html_escape_once(html) end
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 & shut.png" /> tag("img", {src: "open & shut.png"}, false, false) # => <img src="open & shut.png" /> tag("div", data: {name: 'Stephen', city_state: %w(Chicago IL)}) # => <div data-name="Stephen" data-city-state="["Chicago","IL"]" />
# File lib/action_view/helpers/tag_helper.rb, line 74 def tag(name, options = nil, open = false, escape = true) "<#{name}#{tag_options(options, escape) if options}#{open ? ">" : " />"}".html_safe end
Private Instance Methods
# File lib/action_view/helpers/tag_helper.rb, line 174 def boolean_tag_option(key) %Q(#{key}="#{key}") end
# File lib/action_view/helpers/tag_helper.rb, line 143 def content_tag_string(name, content, options, escape = true) tag_options = tag_options(options, escape) if options content = ERB::Util.unwrapped_html_escape(content) if escape "<#{name}#{tag_options}>#{PRE_CONTENT_STRINGS[name.to_sym]}#{content}</#{name}>".html_safe end
# File lib/action_view/helpers/tag_helper.rb, line 166 def prefix_tag_option(prefix, key, value, escape) key = "#{prefix}-#{key.to_s.dasherize}" unless value.is_a?(String) || value.is_a?(Symbol) || value.is_a?(BigDecimal) value = value.to_json end tag_option(key, value, escape) end
# File lib/action_view/helpers/tag_helper.rb, line 178 def tag_option(key, value, escape) if value.is_a?(Array) value = escape ? safe_join(value, " ") : value.join(" ") else value = escape ? ERB::Util.unwrapped_html_escape(value) : value end %Q(#{key}="#{value}") end
# File lib/action_view/helpers/tag_helper.rb, line 149 def tag_options(options, escape = true) return if options.blank? attrs = [] options.each_pair do |key, value| if TAG_PREFIXES.include?(key) && value.is_a?(Hash) value.each_pair do |k, v| attrs << prefix_tag_option(key, k, v, escape) end elsif BOOLEAN_ATTRIBUTES.include?(key) attrs << boolean_tag_option(key) if value elsif !value.nil? attrs << tag_option(key, value, escape) end end " #{attrs * ' '}" unless attrs.empty? end