Module: ActionView::Helpers::UrlHelper

Extended by:
ActiveSupport::Concern
Includes:
TagHelper
Included in:
ActionView::Helpers, FormHelper, FormTagHelper
Defined in:
lib/action_view/helpers/url_helper.rb

Overview

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.

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

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.

%w{patch put delete}

Constants included from TagHelper

TagHelper::ARIA_PREFIXES, TagHelper::BOOLEAN_ATTRIBUTES, TagHelper::DATA_PREFIXES, TagHelper::PRE_CONTENT_STRINGS, TagHelper::TAG_TYPES

Instance Method Summary collapse

Methods included from TagHelper

build_tag_values, #cdata_section, #content_tag, #escape_once, #tag, #token_list

Methods included from OutputSafetyHelper

#raw, #safe_join, #to_sentence

Methods included from CaptureHelper

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

Instance Method Details

#button_to(name = nil, options = nil, html_options = nil, &block) ⇒ Object

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.

You can control the form and button behavior with html_options. Most values in html_options are passed through to the button element. For example, passing a :class option within html_options will set the class attribute of the button element.

The class attribute of the form element can be set by passing a :form_class option within html_options. It defaults to "button_to" to allow styling of the form and its children.

The form submits a POST request by default. You can specify a different HTTP verb via the :method option within html_options.

Options

The options hash accepts the same options as url_for. To generate a <form> element without an [action] attribute, pass false:

<%= button_to "New", false %>
# => "<form method="post" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#    </form>"

Most values in html_options are passed through to the button element, but there are a few special 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.

  • :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.

Examples

<%= button_to "New", action: "new" %>
# => "<form method="post" action="/controller/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6" autocomplete="off"/>
#    </form>"

<%= button_to "New", new_article_path %>
# => "<form method="post" action="/articles/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6" autocomplete="off"/>
#    </form>"

<%= button_to "New", new_article_path, params: { time: Time.now  } %>
# => "<form method="post" action="/articles/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#      <input type="hidden" name="time" value="2021-04-08 14:06:09 -0500" autocomplete="off">
#    </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>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"

<%= button_to "New", { action: "new" }, form_class: "new-thing" %>
# => "<form method="post" action="/controller/new" class="new-thing">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"

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

Deprecated: Rails UJS Attributes

Prior to Rails 7, Rails shipped with a JavaScript library called @rails/ujs on by default. Following Rails 7, this library is no longer on by default. This library integrated with the following options:

  • :remote - If set to true, will allow @rails/ujs to control the submit behavior. By default this behavior is an Ajax submit.

@rails/ujs also integrated with the following :data options:

  • confirm: "question?" - This will allow @rails/ujs to prompt with the question specified (in this case, the resulting text would be question?). If the user accepts, the button 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.

Rails UJS Examples
<%= 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">
#      <button type="submit">Create</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"



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# File 'lib/action_view/helpers/url_helper.rb', line 331

def button_to(name = nil, options = nil, html_options = nil, &block)
  html_options, options = options, name if block_given?
  html_options ||= {}
  html_options = html_options.stringify_keys

  url =
    case options
    when FalseClass then nil
    else url_for(options)
    end

  remote = html_options.delete("remote")
  params = html_options.delete("params")

  authenticity_token = html_options.delete("authenticity_token")

  method     = (html_options.delete("method").presence || method_for_options(options)).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[:method] = form_method
  form_options[:action] = url
  form_options[:'data-remote'] = true if remote

  request_token_tag = if form_method == "post"
    request_method = method.empty? ? "post" : method
    token_tag(authenticity_token, form_options: { action: url, method: request_method })
  else
    ""
  end

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

  button = if block_given?
    content_tag("button", html_options, &block)
  elsif button_to_generates_button_tag
    content_tag("button", name || url, 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
    to_form_params(params).each do |param|
      inner_tags.safe_concat tag(:input, type: "hidden", name: param[:name], value: param[:value],
                                 autocomplete: "off")
    end
  end
  content_tag("form", inner_tags, form_options)
end

#current_page?(*args) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/action_view/helpers/url_helper.rb', line 582

def current_page?(options = nil, check_parameters: false, **options_as_kwargs)
  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?

  options ||= options_as_kwargs
  check_parameters ||= options.is_a?(Hash) && options.delete(:check_parameters)
  url_string = URI::DEFAULT_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
  # the behaviour can be disabled with check_parameters: true
  request_uri = url_string.index("?") || check_parameters ? request.fullpath : request.path
  request_uri = URI::DEFAULT_PARSER.unescape(request_uri).force_encoding(Encoding::BINARY)

  if %r{^\w+://}.match?(url_string)
    request_uri = +"#{request.protocol}#{request.host_with_port}#{request_uri}"
  end

  remove_trailing_slash!(url_string)
  remove_trailing_slash!(request_uri)

  url_string == request_uri
end

#link_to(name = nil, options = nil, html_options = nil, &block) ⇒ Object

Creates an anchor element of the given name using a URL created by the set of options. See the valid options in the documentation for url_for. It's also possible to pass a String instead of an options hash, which generates an anchor element that uses the value of the String as the href for the link. Using a :back Symbol instead of an options hash will generate a link to the referrer (a JavaScript back link will be used in place of a referrer if none exists). If nil is passed as the name the value of the link itself will become the name.

Signatures

link_to(body, url, html_options = {})
  # url is a String; you can use URL helpers like
  # posts_path

link_to(body, url_options = {}, html_options = {})
  # url_options, except :method, is passed to url_for

link_to(options = {}, html_options = {}) do
  # name
end

link_to(url, html_options = {}) do
  # name
end

link_to(active_record_model)

Options

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

Examples

Because it relies on url_for, link_to supports both older-style controller/action/id arguments and newer RESTful routes. Current Rails style favors RESTful routes whenever possible, so base your application on resources and use

link_to "Profile", profile_path(@profile)
# => <a href="/profiles/1">Profile</a>

or the even pithier

link_to "Profile", @profile
# => <a href="/profiles/1">Profile</a>

in place of the older more verbose, non-resource-oriented

link_to "Profile", controller: "profiles", action: "show", id: @profile
# => <a href="/profiles/show/1">Profile</a>

Similarly,

link_to "Profiles", profiles_path
# => <a href="/profiles">Profiles</a>

is better than

link_to "Profiles", controller: "profiles"
# => <a href="/profiles">Profiles</a>

When name is nil the href is presented instead

link_to nil, "http://example.com"
# => <a href="http://www.example.com">http://www.example.com</a>

More concise yet, when name is an Active Record model that defines a to_s method returning a default value or a model instance attribute

link_to @profile
# => <a href="http://www.example.com/profiles/1">Eileen</a>

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

<%= link_to(@profile) do %>
  <strong><%= @profile.name %></strong> -- <span>Check it out!</span>
<% end %>
# => <a href="/profiles/1">
       <strong>David</strong> -- <span>Check it out!</span>
     </a>

Classes and ids for CSS are easy to produce:

link_to "Articles", articles_path, id: "news", class: "article"
# => <a href="/articles" class="article" id="news">Articles</a>

Be careful when using the older argument style, as an extra literal hash is needed:

link_to "Articles", { controller: "articles" }, id: "news", class: "article"
# => <a href="/articles" class="article" id="news">Articles</a>

Leaving the hash off gives the wrong link:

link_to "WRONG!", controller: "articles", id: "news", class: "article"
# => <a href="/articles/index/news?class=article">WRONG!</a>

link_to can also produce links with anchors or query strings:

link_to "Comment wall", profile_path(@profile, anchor: "wall")
# => <a href="/profiles/1#wall">Comment wall</a>

link_to "Ruby on Rails search", controller: "searches", query: "ruby on rails"
# => <a href="/searches?query=ruby+on+rails">Ruby on Rails search</a>

link_to "Nonsense search", searches_path(foo: "bar", baz: "quux")
# => <a href="/searches?foo=bar&baz=quux">Nonsense search</a>

You can set any link attributes such as target, rel, type:

link_to "External link", "http://www.rubyonrails.org/", target: "_blank", rel: "nofollow"
# => <a href="http://www.rubyonrails.org/" target="_blank" rel="nofollow">External link</a>

Deprecated: Rails UJS Attributes

Prior to Rails 7, Rails shipped with a JavaScript library called @rails/ujs on by default. Following Rails 7, this library is no longer on by default. This library integrated with the following options:

  • method: symbol of HTTP verb - This modifier will dynamically create an HTML form and immediately submit the form for processing using the HTTP verb specified. Useful for having links perform a POST operation in dangerous actions like deleting a record (which search bots can follow while spidering your site). Supported verbs are :post, :delete, :patch, and :put. Note that if the user has JavaScript disabled, the request will fall back to using GET. If href: '#' is used and the user has JavaScript disabled clicking the link will have no effect. If you are relying on the POST behavior, you should check for it in your controller's action by using the request object's methods for post?, delete?, patch?, or put?.

  • remote: true - This will allow @rails/ujs to make an Ajax request to the URL in question instead of following the link.

@rails/ujs also integrated with the following :data options:

  • confirm: "question?" - This will allow @rails/ujs to prompt with the question specified (in this case, the resulting text would be question?). 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 name for a disabled version of the link.

Rails UJS Examples
link_to "Remove Profile", profile_path(@profile), method: :delete
# => <a href="/profiles/1" rel="nofollow" data-method="delete">Remove Profile</a>

link_to "Visit Other Site", "http://www.rubyonrails.org/", data: { confirm: "Are you sure?" }
# => <a href="http://www.rubyonrails.org/" data-confirm="Are you sure?">Visit Other Site</a>



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# File 'lib/action_view/helpers/url_helper.rb', line 209

def link_to(name = nil, options = nil, html_options = nil, &block)
  html_options, options, name = options, name, block if block_given?
  options ||= {}

  html_options = convert_options_to_data_attributes(options, html_options)

  url = url_target(name, options)
  html_options["href"] ||= url

  content_tag("a", name || url, html_options, &block)
end

#link_to_if(condition, name, options = {}, html_options = {}, &block) ⇒ Object

Creates a link tag of the given name using a URL created by the set of options if condition is true, otherwise only the name is returned. To specialize the default behavior, you can pass a block that accepts the name or the full argument list for link_to_if.

Examples

<%= link_to_if(@current_user.nil?, "Login", { controller: "sessions", action: "new" }) %>
# If the user isn't logged in...
# => <a href="/sessions/new/">Login</a>

<%=
   link_to_if(@current_user.nil?, "Login", { controller: "sessions", action: "new" }) do
     link_to(@current_user.login, { controller: "accounts", action: "show", id: @current_user })
   end
%>
# If the user isn't logged in...
# => <a href="/sessions/new/">Login</a>
# If they are logged in...
# => <a href="/accounts/show/3">my_username</a>



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# File 'lib/action_view/helpers/url_helper.rb', line 471

def link_to_if(condition, name, options = {}, html_options = {}, &block)
  if condition
    link_to(name, options, html_options)
  else
    if block_given?
      block.arity <= 1 ? capture(name, &block) : capture(name, options, html_options, &block)
    else
      ERB::Util.html_escape(name)
    end
  end
end

#link_to_unless(condition, name, options = {}, html_options = {}, &block) ⇒ Object

Creates a link tag of the given name using a URL created by the set of options unless condition is true, in which case only the name is returned. To specialize the default behavior (i.e., show a login link rather than just the plaintext link text), you can pass a block that accepts the name or the full argument list for link_to_unless.

Examples

<%= link_to_unless(@current_user.nil?, "Reply", { action: "reply" }) %>
# If the user is logged in...
# => <a href="/controller/reply/">Reply</a>

<%=
   link_to_unless(@current_user.nil?, "Reply", { action: "reply" }) do |name|
     link_to(name, { controller: "accounts", action: "signup" })
   end
%>
# If the user is logged in...
# => <a href="/controller/reply/">Reply</a>
# If not...
# => <a href="/accounts/signup">Reply</a>



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# File 'lib/action_view/helpers/url_helper.rb', line 448

def link_to_unless(condition, name, options = {}, html_options = {}, &block)
  link_to_if !condition, name, options, html_options, &block
end

#link_to_unless_current(name, options = {}, html_options = {}, &block) ⇒ Object

Creates a link tag of the given name using a URL created by the set of options unless the current request URI is the same as the links, in which case only the name is returned (or the given block is yielded, if one exists). You can give link_to_unless_current a block which will specialize the default behavior (e.g., show a “Start Here” link rather than the link's text).

Examples

Let's say you have a navigation menu…

<ul id="navbar">
  <li><%= link_to_unless_current("Home", { action: "index" }) %></li>
  <li><%= link_to_unless_current("About Us", { action: "about" }) %></li>
</ul>

If in the “about” action, it will render…

<ul id="navbar">
  <li><a href="/controller/index">Home</a></li>
  <li>About Us</li>
</ul>

…but if in the “index” action, it will render:

<ul id="navbar">
  <li>Home</li>
  <li><a href="/controller/about">About Us</a></li>
</ul>

The implicit block given to link_to_unless_current is evaluated if the current action is the action given. So, if we had a comments page and wanted to render a “Go Back” link instead of a link to the comments page, we could do something like this…

<%=
    link_to_unless_current("Comment", { controller: "comments", action: "new" }) do
       link_to("Go back", { controller: "posts", action: "index" })
    end
 %>



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# File 'lib/action_view/helpers/url_helper.rb', line 424

def link_to_unless_current(name, options = {}, html_options = {}, &block)
  link_to_unless current_page?(options), name, options, html_options, &block
end

#mail_to(email_address, name = nil, html_options = {}, &block) ⇒ Object

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.

  • :reply_to - Preset the Reply-To field of 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", 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">me@domain.com</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>



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# File 'lib/action_view/helpers/url_helper.rb', line 521

def mail_to(email_address, name = nil, html_options = {}, &block)
  html_options, name = name, nil if name.is_a?(Hash)
  html_options = (html_options || {}).stringify_keys

  extras = %w{ cc bcc body subject reply_to }.map! { |item|
    option = html_options.delete(item).presence || next
    "#{item.dasherize}=#{ERB::Util.url_encode(option)}"
  }.compact
  extras = extras.empty? ? "" : "?" + extras.join("&")

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

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

#phone_to(phone_number, name = nil, html_options = {}, &block) ⇒ Object

Creates a TEL anchor link tag to the specified phone_number. When the link is clicked, the default app to make phone calls is opened and prepopulated with the phone number.

If name is not specified, phone_number will be used as the name of the link.

A country_code option is supported, which prepends a plus sign and the given country code to the linked phone number. For example, country_code: "01" will prepend +01 to the linked phone number.

Additional HTML attributes for the link can be passed via html_options.

Options

  • :country_code - Prepends the country code to the phone number

Examples

phone_to "1234567890"
# => <a href="tel:1234567890">1234567890</a>

phone_to "1234567890", "Phone me"
# => <a href="tel:1234567890">Phone me</a>

phone_to "1234567890", country_code: "01"
# => <a href="tel:+011234567890">1234567890</a>

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

<%= phone_to "1234567890" do %>
  <strong>Phone me:</strong>
<% end %>
# => <a href="tel:1234567890">
       <strong>Phone me:</strong>
     </a>



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# File 'lib/action_view/helpers/url_helper.rb', line 716

def phone_to(phone_number, name = nil, html_options = {}, &block)
  html_options, name = name, nil if name.is_a?(Hash)
  html_options = (html_options || {}).stringify_keys

  country_code = html_options.delete("country_code").presence
  country_code = country_code.nil? ? "" : "+#{ERB::Util.url_encode(country_code)}"

  encoded_phone_number = ERB::Util.url_encode(phone_number)
  html_options["href"] = "tel:#{country_code}#{encoded_phone_number}"

  content_tag("a", name || phone_number, html_options, &block)
end

#sms_to(phone_number, name = nil, html_options = {}, &block) ⇒ Object

Creates an SMS anchor link tag to the specified phone_number. When the link is clicked, the default SMS messaging app is opened ready to send a message to the linked phone number. If the body option is specified, the contents of the message will be preset to body.

If name is not specified, phone_number will be used as the name of the link.

A country_code option is supported, which prepends a plus sign and the given country code to the linked phone number. For example, country_code: "01" will prepend +01 to the linked phone number.

Additional HTML attributes for the link can be passed via html_options.

Options

  • :country_code - Prepend the country code to the phone number.

  • :body - Preset the body of the message.

Examples

sms_to "5155555785"
# => <a href="sms:5155555785;">5155555785</a>

sms_to "5155555785", country_code: "01"
# => <a href="sms:+015155555785;">5155555785</a>

sms_to "5155555785", "Text me"
# => <a href="sms:5155555785;">Text me</a>

sms_to "5155555785", body: "I have a question about your product."
# => <a href="sms:5155555785;?body=I%20have%20a%20question%20about%20your%20product">5155555785</a>

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

<%= sms_to "5155555785" do %>
  <strong>Text me:</strong>
<% end %>
# => <a href="sms:5155555785;">
       <strong>Text me:</strong>
     </a>



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# File 'lib/action_view/helpers/url_helper.rb', line 665

def sms_to(phone_number, name = nil, html_options = {}, &block)
  html_options, name = name, nil if name.is_a?(Hash)
  html_options = (html_options || {}).stringify_keys

  country_code = html_options.delete("country_code").presence
  country_code = country_code ? "+#{ERB::Util.url_encode(country_code)}" : ""

  body = html_options.delete("body").presence
  body = body ? "?&body=#{ERB::Util.url_encode(body)}" : ""

  encoded_phone_number = ERB::Util.url_encode(phone_number)
  html_options["href"] = "sms:#{country_code}#{encoded_phone_number};#{body}"

  content_tag("a", name || phone_number, html_options, &block)
end

#url_for(options = nil) ⇒ Object

Basic implementation of url_for to allow use helpers without routes existence



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# File 'lib/action_view/helpers/url_helper.rb', line 35

def url_for(options = nil) # :nodoc:
  case options
  when String
    options
  when :back
    _back_url
  else
    raise ArgumentError, "arguments passed to url_for can't be handled. Please require " \
                         "routes or provide your own implementation"
  end
end