Module: ActionView::Helpers::UrlHelper
- Includes:
- JavaScriptHelper
- 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 ActionController::Routing). This allows you to use the same format for links in views and controllers.
Instance Method Summary collapse
-
#button_to(name, options = {}, html_options = {}) ⇒ Object
Generates a form containing a single button that submits to the URL created by the set of
options
. -
#current_page?(options) ⇒ Boolean
True if the current request URI was generated by the given
options
. -
#link_to(name, options = {}, html_options = nil) ⇒ Object
Creates a link tag of the given
name
using a URL created by the set ofoptions
. -
#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 ofoptions
ifcondition
is true, in which case only the name is returned. -
#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 ofoptions
unlesscondition
is true, in which case only the name is returned. -
#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 ofoptions
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). -
#mail_to(email_address, name = nil, html_options = {}) ⇒ Object
Creates a mailto link tag to the specified
email_address
, which is also used as the name of the link unlessname
is specified. -
#url_for(options = {}) ⇒ Object
Returns the URL for the set of
options
provided.
Methods included from JavaScriptHelper
#button_to_function, #escape_javascript, #javascript_cdata_section, #javascript_tag, #link_to_function
Instance Method Details
#button_to(name, options = {}, html_options = {}) ⇒ 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.
The generated FORM element has a class name of button-to
to allow styling of the form itself and its children. You can control the form submission and input element behavior using html_options
. This method accepts the :method
and :confirm
modifiers 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 at url_for.
There are a few special html_options
:
-
:method
- Specifies the anchor name to be appended to the path. -
:disabled
- Specifies the anchor name to be appended to the path. -
:confirm
- This will add a JavaScript confirm prompt with the question specified. If the user accepts, the link is processed normally, otherwise no action is taken.
Examples
<%= button_to "New", :action => "new" %>
# => "<form method="post" action="/controller/new" class="button-to">
# <div><input value="New" type="submit" /></div>
# </form>"
button_to "Delete Image", { :action => "delete", :id => @image.id },
:confirm => "Are you sure?", :method => :delete
# => "<form method="post" action="/images/delete/1" class="button-to">
# <div>
# <input type="hidden" name="_method" value="delete" />
# <input onclick="return confirm('Are you sure?');"
# value="Delete" type="submit" />
# </div>
# </form>"
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# File 'lib/action_view/helpers/url_helper.rb', line 255 def (name, = {}, = {}) = .stringify_keys convert_boolean_attributes!(, %w( disabled )) method_tag = '' if (method = .delete('method')) && %w{put delete}.include?(method.to_s) method_tag = tag('input', :type => 'hidden', :name => '_method', :value => method.to_s) end form_method = method.to_s == 'get' ? 'get' : 'post' request_token_tag = '' if form_method == 'post' && protect_against_forgery? request_token_tag = tag(:input, :type => "hidden", :name => request_forgery_protection_token.to_s, :value => form_authenticity_token) end if confirm = .delete("confirm") ["onclick"] = "return #{confirm_javascript_function(confirm)};" end url = .is_a?(String) ? : self.url_for() name ||= url .merge!("type" => "submit", "value" => name) "<form method=\"#{form_method}\" action=\"#{escape_once url}\" class=\"button-to\"><div>" + method_tag + tag("input", ) + request_token_tag + "</div></form>" end |
#current_page?(options) ⇒ Boolean
True if the current request URI was generated by the given options
.
Examples
Let’s say we’re in the /shop/checkout
action.
current_page?(:action => 'process')
# => false
current_page?(:controller => 'shop', :action => 'checkout')
# => true
current_page?(:action => 'checkout')
# => true
current_page?(:controller => 'library', :action => 'checkout')
# => false
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# File 'lib/action_view/helpers/url_helper.rb', line 484 def current_page?() url_string = CGI.escapeHTML(url_for()) request = @controller.request if url_string =~ /^\w+:\/\// url_string == "#{request.protocol}#{request.host_with_port}#{request.request_uri}" else url_string == request.request_uri end end |
#link_to(name, options = {}, html_options = nil) ⇒ Object
Creates a link tag 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 to get a link tag that uses the value of the string as the href for the link, or use :back
to link to the referrer - a JavaScript back link will be used in place of a referrer if none exists. If nil is passed as a name, the link itself will become the name.
Options
-
:confirm => 'question?'
- This will add a JavaScript confirm prompt with the question specified. If the user accepts, the link is processed normally, otherwise no action is taken. -
:popup => true || array of window options
- This will force the link to open in a popup window. By passing true, a default browser window will be opened with the URL. You can also specify an array of options that are passed-thru to JavaScripts window.open method. -
: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
and:put
. Note that if the user has JavaScript disabled, the request will fall back to using GET. 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 forpost?
,delete?
orput?
. -
The
html_options
will accept a hash of html attributes for the link tag.
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, your should check for it in your controller’s action by using the request object’s methods for post?
, delete?
or put?
.
You can mix and match the html_options
with the exception of :popup
and :method
which will raise an ActionView::ActionViewError exception.
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>
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>
The three options specfic to link_to
(:confirm
, :popup
, and :method
) are used as follows:
link_to "Visit Other Site", "http://www.rubyonrails.org/", :confirm => "Are you sure?"
# => <a href="http://www.rubyonrails.org/" onclick="return confirm('Are you sure?');">Visit Other Site</a>
link_to "Help", { :action => "help" }, :popup => true
# => <a href="/testing/help/" onclick="window.open(this.href);return false;">Help</a>
link_to "View Image", @image, :popup => ['new_window_name', 'height=300,width=600']
# => <a href="/images/9" onclick="window.open(this.href,'new_window_name','height=300,width=600');return false;">View Image</a>
link_to "Delete Image", @image, :confirm => "Are you sure?", :method => :delete
# => <a href="/images/9" onclick="if (confirm('Are you sure?')) { var f = document.createElement('form');
f.style.display = 'none'; this.parentNode.appendChild(f); f.method = 'POST'; f.action = this.href;
var m = document.createElement('input'); m.setAttribute('type', 'hidden'); m.setAttribute('name', '_method');
m.setAttribute('value', 'delete'); f.appendChild(m);f.submit(); };return false;">Delete Image</a>
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# File 'lib/action_view/helpers/url_helper.rb', line 190 def link_to(name, = {}, = nil) url = case when String when :back @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()' else self.url_for() end if = .stringify_keys href = ['href'] (, url) = () else = nil end href_attr = "href=\"#{url}\"" unless href "<a #{href_attr}#{}>#{name || url}</a>" 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, in which case 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_unless (see the examples in link_to_unless).
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 379 def link_to_if(condition, name, = {}, = {}, &block) link_to_unless !condition, name, , , &block 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 347 def link_to_unless(condition, name, = {}, = {}, &block) if condition if block_given? block.arity <= 1 ? yield(name) : yield(name, , ) else name end else link_to(name, , ) end 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 323 def link_to_unless_current(name, = {}, = {}, &block) link_to_unless current_page?(), name, , , &block end |
#mail_to(email_address, name = nil, html_options = {}) ⇒ 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 hindering email harvesters and customizing the email itself by passing special keys to html_options
.
Options
-
:encode
- This key will accept the strings “javascript” or “hex”. Passing “javascript” will dynamically create and encode the mailto: link then eval it into the DOM of the page. This method will not show the link on the page if the user has JavaScript disabled. Passing “hex” will hex encode theemail_address
before outputting the mailto: link. -
:replace_at
- When the linkname
isn’t provided, theemail_address
is used for the link label. You can use this option to obfuscate theemail_address
by substituting the @ sign with the string given as the value. -
:replace_dot
- When the linkname
isn’t provided, theemail_address
is used for the link label. You can use this option to obfuscate theemail_address
by substituting the . in the email with the string given as the value. -
:subject
- Preset the subject line of the email. -
:body
- Preset the body of the email. -
:cc
- Carbon Copy addition recipients on the email. -
:bcc
- Blind Carbon Copy additional recipients on the email.
Examples
mail_to "[email protected]"
# => <a href="mailto:[email protected]">[email protected]</a>
mail_to "[email protected]", "My email", :encode => "javascript"
# => <script type="text/javascript">eval(unescape('%64%6f%63...%6d%65%6e'))</script>
mail_to "[email protected]", "My email", :encode => "hex"
# => <a href="mailto:%6d%65@%64%6f%6d%61%69%6e.%63%6f%6d">My email</a>
mail_to "[email protected]", nil, :replace_at => "_at_", :replace_dot => "_dot_", :class => "email"
# => <a href="mailto:[email protected]" class="email">me_at_domain_dot_com</a>
mail_to "[email protected]", "My email", :cc => "[email protected]",
:subject => "This is an example email"
# => <a href="mailto:[email protected][email protected]&subject=This%20is%20an%20example%20email">My email</a>
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# File 'lib/action_view/helpers/url_helper.rb', line 425 def mail_to(email_address, name = nil, = {}) = .stringify_keys encode = .delete("encode").to_s cc, bcc, subject, body = .delete("cc"), .delete("bcc"), .delete("subject"), .delete("body") string = '' extras = '' extras << "cc=#{CGI.escape(cc).gsub("+", "%20")}&" unless cc.nil? extras << "bcc=#{CGI.escape(bcc).gsub("+", "%20")}&" unless bcc.nil? extras << "body=#{CGI.escape(body).gsub("+", "%20")}&" unless body.nil? extras << "subject=#{CGI.escape(subject).gsub("+", "%20")}&" unless subject.nil? extras = "?" << extras.gsub!(/&?$/,"") unless extras.empty? email_address = email_address.to_s = email_address.dup .gsub!(/@/, .delete("replace_at")) if .has_key?("replace_at") .gsub!(/\./, .delete("replace_dot")) if .has_key?("replace_dot") if encode == "javascript" "document.write('#{content_tag("a", name || , .merge({ "href" => "mailto:"+email_address+extras }))}');".each_byte do |c| string << sprintf("%%%x", c) end "<script type=\"#{Mime::JS}\">eval(unescape('#{string}'))</script>" elsif encode == "hex" email_address_encoded = '' .each_byte do |c| email_address_encoded << sprintf("&#%d;", c) end protocol = 'mailto:' protocol.each_byte { |c| string << sprintf("&#%d;", c) } email_address.each_byte do |c| char = c.chr string << (char =~ /\w/ ? sprintf("%%%x", c) : char) end content_tag "a", name || email_address_encoded, .merge({ "href" => "#{string}#{extras}" }) else content_tag "a", name || , .merge({ "href" => "mailto:#{email_address}#{extras}" }) end end |
#url_for(options = {}) ⇒ Object
Returns the URL for the set of options
provided. This takes the same options as url_for
in Action Controller (see the documentation for ActionController::Base#url_for). Note that by default :only_path
is true
so you’ll get the relative /controller/action instead of the fully qualified URL like example.com/controller/action.
When called from a view, url_for returns an HTML escaped url. If you need an unescaped url, pass :escape => false
in the options
.
Options
-
:anchor
- Specifies the anchor name to be appended to the path. -
:only_path
- If true, returns the relative URL (omitting the protocol, host name, and port) (true
by default unless:host
is specified). -
:trailing_slash
- If true, adds a trailing slash, as in “/archive/2005/”. Note that this is currently not recommended since it breaks caching. -
:host
- Overrides the default (current) host if provided. -
:protocol
- Overrides the default (current) protocol if provided. -
:user
- Inline HTTP authentication (only plucked out if:password
is also present). -
:password
- Inline HTTP authentication (only plucked out if:user
is also present). -
:escape
- Determines whether the returned URL will be HTML escaped or not (true
by default).
Relying on named routes
If you instead of a hash pass a record (like an Active Record or Active Resource) as the options parameter, you’ll trigger the named route for that record. The lookup will happen on the name of the class. So passing a Workshop object will attempt to use the workshop_path route. If you have a nested route, such as admin_workshop_path you’ll have to call that explicitly (it’s impossible for url_for to guess that route).
Examples
<%= url_for(:action => 'index') %>
# => /blog/
<%= url_for(:action => 'find', :controller => 'books') %>
# => /books/find
<%= url_for(:action => 'login', :controller => 'members', :only_path => false, :protocol => 'https') %>
# => https://www.railsapplication.com/members/login/
<%= url_for(:action => 'play', :anchor => 'player') %>
# => /messages/play/#player
<%= url_for(:action => 'checkout', :anchor => 'tax&ship') %>
# => /testing/jump/#tax&ship
<%= url_for(:action => 'checkout', :anchor => 'tax&ship', :escape => false) %>
# => /testing/jump/#tax&ship
<%= url_for(Workshop.new) %>
# relies on Workshop answering a new_record? call (and in this case returning true)
# => /workshops
<%= url_for(@workshop) %>
# calls @workshop.to_s
# => /workshops/5
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# File 'lib/action_view/helpers/url_helper.rb', line 65 def url_for( = {}) ||= {} case when Hash = { :only_path => [:host].nil? }.update(.symbolize_keys) escape = .key?(:escape) ? .delete(:escape) : true url = @controller.send(:url_for, ) when String escape = true url = else escape = false url = polymorphic_path() end escape ? escape_once(url) : url end |