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
# File actionview/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 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 actionview/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 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 actionview/lib/action_view/helpers/tag_helper.rb, line 137 def escape_once(html) ERB::Util.html_escape_once(html) 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 actionview/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
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"]" />
© 2004–2018 David Heinemeier Hansson
Licensed under the MIT License.