module ActionView::Helpers::UrlHelper

Provides a set of methods for making links and getting URLs that depend on the routing subsystem (see ActionDispatch::Routing). This allows you to use the same format for links in views and controllers.

Constants

BUTTON_TAG_METHOD_VERBS

This helper may be included in any class that includes the URL helpers of a routes (routes.url_helpers). Some methods provided here will only work in the context of a request (link_to_unless_current, for instance), which must be provided as a method called request on the context.

Public Instance Methods

button_to(name = nil, options = nil, html_options = nil, &block) click to toggle source

Generates a form containing a single button that submits to the URL created by the set of options. This is the safest method to ensure links that cause changes to your data are not triggered by search bots or accelerators. If the HTML button does not work with your layout, you can also consider using the link_to method with the :method modifier as described in the link_to documentation.

By default, the generated form element has a class name of button_to to allow styling of the form itself and its children. This can be changed using the :form_class modifier within html_options. You can control the form submission and input element behavior using html_options. This method accepts the :method modifier described in the link_to documentation. If no :method modifier is given, it will default to performing a POST operation. You can also disable the button by passing disabled: true in html_options. If you are using RESTful routes, you can pass the :method to change the HTTP verb used to submit the form.

Options

The options hash accepts the same options as url_for.

There are a few special html_options:

  • :method - Symbol of HTTP verb. Supported verbs are :post, :get, :delete, :patch, and :put. By default it will be :post.

  • :disabled - If set to true, it will generate a disabled button.

  • :data - This option can be used to add custom data attributes.

  • :remote - If set to true, will allow the Unobtrusive JavaScript drivers to control the submit behavior. By default this behavior is an ajax submit.

  • :form - This hash will be form attributes

  • :form_class - This controls the class of the form within which the submit button will be placed

  • :params - Hash of parameters to be rendered as hidden fields within the form.

Data attributes

  • :confirm - This will use the unobtrusive JavaScript driver to prompt with the question specified. If the user accepts, the link is processed normally, otherwise no action is taken.

  • :disable_with - Value of this parameter will be used as the value for a disabled version of the submit button when the form is submitted. This feature is provided by the unobtrusive JavaScript driver.

Examples

<%= button_to "New", action: "new" %>
# => "<form method="post" action="/controller/new" class="button_to">
#      <input value="New" type="submit" />
#    </form>"

<%= button_to "New", new_articles_path %>
# => "<form method="post" action="/articles/new" class="button_to">
#      <input value="New" type="submit" />
#    </form>"

<%= button_to [:make_happy, @user] do %>
  Make happy <strong><%= @user.name %></strong>
<% end %>
# => "<form method="post" action="/users/1/make_happy" class="button_to">
#      <button type="submit">
#        Make happy <strong><%= @user.name %></strong>
#      </button>
#    </form>"

<%= button_to "New", { action: "new" }, form_class: "new-thing" %>
# => "<form method="post" action="/controller/new" class="new-thing">
#      <input value="New" type="submit" />
#    </form>"

<%= button_to "Create", { action: "create" }, remote: true, form: { "data-type" => "json" } %>
# => "<form method="post" action="/images/create" class="button_to" data-remote="true" data-type="json">
#      <input value="Create" type="submit" />
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#    </form>"

<%= button_to "Delete Image", { action: "delete", id: @image.id },
                                method: :delete, data: { confirm: "Are you sure?" } %>
# => "<form method="post" action="/images/delete/1" class="button_to">
#      <input type="hidden" name="_method" value="delete" />
#      <input data-confirm='Are you sure?' value="Delete Image" type="submit" />
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#    </form>"

<%= button_to('Destroy', 'http://www.example.com',
          method: "delete", remote: true, data: { confirm: 'Are you sure?', disable_with: 'loading...' }) %>
# => "<form class='button_to' method='post' action='http://www.example.com' data-remote='true'>
#       <input name='_method' value='delete' type='hidden' />
#       <input value='Destroy' type='submit' data-disable-with='loading...' data-confirm='Are you sure?' />
#       <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#     </form>"
#
# File lib/action_view/helpers/url_helper.rb, line 279
def button_to(name = nil, options = nil, html_options = nil, &block)
  html_options, options = options, name if block_given?
  options      ||= {}
  html_options ||= {}

  html_options = html_options.stringify_keys
  convert_boolean_attributes!(html_options, %w(disabled))

  url    = options.is_a?(String) ? options : url_for(options)
  remote = html_options.delete('remote')
  params = html_options.delete('params')

  method     = html_options.delete('method').to_s
  method_tag = BUTTON_TAG_METHOD_VERBS.include?(method) ? method_tag(method) : ''.html_safe

  form_method  = method == 'get' ? 'get' : 'post'
  form_options = html_options.delete('form') || {}
  form_options[:class] ||= html_options.delete('form_class') || 'button_to'
  form_options.merge!(method: form_method, action: url)
  form_options.merge!("data-remote" => "true") if remote

  request_token_tag = form_method == 'post' ? token_tag : ''

  html_options = convert_options_to_data_attributes(options, html_options)
  html_options['type'] = 'submit'

  button = if block_given?
    content_tag('button', html_options, &block)
  else
    html_options['value'] = name || url
    tag('input', html_options)
  end

  inner_tags = method_tag.safe_concat(button).safe_concat(request_token_tag)
  if params
    params.each do |param_name, value|
      inner_tags.safe_concat tag(:input, type: "hidden", name: param_name, value: value.to_param)
    end
  end
  content_tag('form', inner_tags, form_options)
end
current_page?(options) click to toggle source

True if the current request URI was generated by the given options.

Examples

Let's say we're in the http://www.example.com/shop/checkout?order=desc action.

current_page?(action: 'process')
# => false

current_page?(controller: 'shop', action: 'checkout')
# => true

current_page?(controller: 'shop', action: 'checkout', order: 'asc')
# => false

current_page?(action: 'checkout')
# => true

current_page?(controller: 'library', action: 'checkout')
# => false

current_page?('http://www.example.com/shop/checkout')
# => true

current_page?('/shop/checkout')
# => true

Let's say we're in the http://www.example.com/shop/checkout?order=desc&page=1 action.

current_page?(action: 'process')
# => false

current_page?(controller: 'shop', action: 'checkout')
# => true

current_page?(controller: 'shop', action: 'checkout', order: 'desc', page: '1')
# => true

current_page?(controller: 'shop', action: 'checkout', order: 'desc', page: '2')
# => false

current_page?(controller: 'shop', action: 'checkout', order: 'desc')
# => false

current_page?(action: 'checkout')
# => true

current_page?(controller: 'library', action: 'checkout')
# => false

Let's say we're in the http://www.example.com/products action with method POST in case of invalid product.

current_page?(controller: 'product', action: 'index')
# => false
# File lib/action_view/helpers/url_helper.rb, line 526
def current_page?(options)
  unless request
    raise "You cannot use helpers that need to determine the current "                  "page unless your view context provides a Request object "                  "in a #request method"
  end

  return false unless request.get? || request.head?

  url_string = URI.parser.unescape(url_for(options)).force_encoding(Encoding::BINARY)

  # We ignore any extra parameters in the request_uri if the
  # submitted url doesn't have any either. This lets the function
  # work with things like ?order=asc
  request_uri = url_string.index("?") ? request.fullpath : request.path
  request_uri = URI.parser.unescape(request_uri).force_encoding(Encoding::BINARY)

  if url_string =~ /^\w+:\/\//
    url_string == "#{request.protocol}#{request.host_with_port}#{request_uri}"
  else
    url_string == request_uri
  end
end
mail_to(email_address, name = nil, html_options = {}, &block) click to toggle source

Creates a mailto link tag to the specified email_address, which is also used as the name of the link unless name is specified. Additional HTML attributes for the link can be passed in html_options.

mail_to has several methods for customizing the email itself by passing special keys to html_options.

Options

  • :subject - Preset the subject line of the email.

  • :body - Preset the body of the email.

  • :cc - Carbon Copy additional recipients on the email.

  • :bcc - Blind Carbon Copy additional recipients on the email.

Obfuscation

Prior to Rails 4.0, mail_to provided options for encoding the address in order to hinder email harvesters. To take advantage of these options, install the actionview-encoded_mail_to gem.

Examples

mail_to "me@domain.com"
# => <a href="mailto:me@domain.com">me@domain.com</a>

mail_to "me@domain.com", "My email"
# => <a href="mailto:me@domain.com">My email</a>

mail_to "me@domain.com", "My email", cc: "ccaddress@domain.com",
         subject: "This is an example email"
# => <a href="mailto:me@domain.com?cc=ccaddress@domain.com&subject=This%20is%20an%20example%20email">My email</a>

You can use a block as well if your link target is hard to fit into the name parameter. ERB example:

<%= mail_to "me@domain.com" do %>
  <strong>Email me:</strong> <span>me@domain.com</span>
<% end %>
# => <a href="mailto:me@domain.com">
       <strong>Email me:</strong> <span>me@domain.com</span>
     </a>
# File lib/action_view/helpers/url_helper.rb, line 456
def mail_to(email_address, name = nil, html_options = {}, &block)
  html_options, name = name, nil if block_given?
  html_options = (html_options || {}).stringify_keys

  extras = %w{ cc bcc body subject }.map! { |item|
    option = html_options.delete(item) || next
    "#{item}=#{Rack::Utils.escape_path(option)}"
  }.compact
  extras = extras.empty? ? '' : '?' + extras.join('&')

  encoded_email_address = ERB::Util.url_encode(email_address ? email_address.to_str : '').gsub("%40", "@")
  html_options["href"] = "mailto:#{encoded_email_address}#{extras}"

  content_tag(:a, name || email_address, html_options, &block)
end

Private Instance Methods

add_method_to_attributes!(html_options, method) click to toggle source
# File lib/action_view/helpers/url_helper.rb, line 572
def add_method_to_attributes!(html_options, method)
  if method && method.to_s.downcase != "get" && html_options["rel"] !~ /nofollow/
    html_options["rel"] = "#{html_options["rel"]} nofollow".lstrip
  end
  html_options["data-method"] = method
end
convert_boolean_attributes!(html_options, bool_attrs) click to toggle source

Processes the html_options hash, converting the boolean attributes from true/false form into the form required by HTML/XHTML. (An attribute is considered to be boolean if its name is listed in the given bool_attrs array.)

More specifically, for each boolean attribute in html_options given as:

"attr" => bool_value

if the associated bool_value evaluates to true, it is replaced with the attribute's name; otherwise the attribute is removed from the html_options hash. (See the XHTML 1.0 spec, section 4.5 “Attribute Minimization” for more: www.w3.org/TR/xhtml1/#h-4.5)

Returns the updated html_options hash, which is also modified in place.

Example:

convert_boolean_attributes!( html_options,
                             %w( checked disabled readonly ) )
# File lib/action_view/helpers/url_helper.rb, line 602
def convert_boolean_attributes!(html_options, bool_attrs)
  bool_attrs.each { |x| html_options[x] = x if html_options.delete(x) }
  html_options
end
convert_options_to_data_attributes(options, html_options) click to toggle source
# File lib/action_view/helpers/url_helper.rb, line 551
def convert_options_to_data_attributes(options, html_options)
  if html_options
    html_options = html_options.stringify_keys
    html_options['data-remote'] = 'true' if link_to_remote_options?(options) || link_to_remote_options?(html_options)

    method  = html_options.delete('method')

    add_method_to_attributes!(html_options, method) if method

    html_options
  else
    link_to_remote_options?(options) ? {'data-remote' => 'true'} : {}
  end
end
method_tag(method) click to toggle source
# File lib/action_view/helpers/url_helper.rb, line 616
def method_tag(method)
  tag('input', type: 'hidden', name: '_method', value: method.to_s)
end
token_tag(token=nil) click to toggle source
# File lib/action_view/helpers/url_helper.rb, line 607
def token_tag(token=nil)
  if token != false && protect_against_forgery?
    token ||= form_authenticity_token
    tag(:input, type: "hidden", name: request_forgery_protection_token.to_s, value: token)
  else
    ''
  end
end