Module | ActionView::Helpers::UrlHelper |
In: |
vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb
|
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.
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.
The options hash accepts the same options at url_for.
There are a few special html_options:
<%= 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>"
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 202 202: def button_to(name, options = {}, html_options = {}) 203: html_options = html_options.stringify_keys 204: convert_boolean_attributes!(html_options, %w( disabled )) 205: 206: method_tag = '' 207: if (method = html_options.delete('method')) && %w{put delete}.include?(method.to_s) 208: method_tag = tag('input', :type => 'hidden', :name => '_method', :value => method.to_s) 209: end 210: 211: form_method = method.to_s == 'get' ? 'get' : 'post' 212: 213: request_token_tag = '' 214: if form_method == 'post' && protect_against_forgery? 215: request_token_tag = tag(:input, :type => "hidden", :name => request_forgery_protection_token.to_s, :value => form_authenticity_token) 216: end 217: 218: if confirm = html_options.delete("confirm") 219: html_options["onclick"] = "return #{confirm_javascript_function(confirm)};" 220: end 221: 222: url = options.is_a?(String) ? options : self.url_for(options) 223: name ||= url 224: 225: html_options.merge!("type" => "submit", "value" => name) 226: 227: "<form method=\"#{form_method}\" action=\"#{escape_once url}\" class=\"button-to\"><div>" + 228: method_tag + tag("input", html_options) + request_token_tag + "</div></form>" 229: end
True if the current request URI was generated by the given options.
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
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 435 435: def current_page?(options) 436: url_string = CGI.escapeHTML(url_for(options)) 437: request = @controller.request 438: if url_string =~ /^\w+:\/\// 439: url_string == "#{request.protocol}#{request.host_with_port}#{request.request_uri}" 440: else 441: url_string == request.request_uri 442: end 443: end
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.
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.
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", { :action => "view" }, :popup => ['new_window_name', 'height=300,width=600'] # => <a href="/testing/view/" onclick="window.open(this.href,'new_window_name','height=300,width=600');return false;">View Image</a> link_to "Delete Image", { :action => "delete", :id => @image.id }, :confirm => "Are you sure?", :method => :delete # => <a href="/testing/delete/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>
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 137 137: def link_to(name, options = {}, html_options = nil) 138: url = case options 139: when String 140: options 141: when :back 142: @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()' 143: else 144: self.url_for(options) 145: end 146: 147: if html_options 148: html_options = html_options.stringify_keys 149: href = html_options['href'] 150: convert_options_to_javascript!(html_options, url) 151: tag_options = tag_options(html_options) 152: else 153: tag_options = nil 154: end 155: 156: href_attr = "href=\"#{url}\"" unless href 157: "<a #{href_attr}#{tag_options}>#{name || url}</a>" 158: end
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).
<%= 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>
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 326 326: def link_to_if(condition, name, options = {}, html_options = {}, &block) 327: link_to_unless !condition, name, options, html_options, &block 328: end
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.
<%= 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>
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 294 294: def link_to_unless(condition, name, options = {}, html_options = {}, &block) 295: if condition 296: if block_given? 297: block.arity <= 1 ? yield(name) : yield(name, options, html_options) 298: else 299: name 300: end 301: else 302: link_to(name, options, html_options) 303: end 304: end
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).
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 "home" action, it will render:
<ul id="navbar"> <li><a href="/controller/index">Home</a></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 %>
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 270 270: def link_to_unless_current(name, options = {}, html_options = {}, &block) 271: link_to_unless current_page?(options), name, options, html_options, &block 272: end
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.
mail_to "me@domain.com" # => <a href="mailto:me@domain.com">me@domain.com</a> mail_to "me@domain.com", "My email", :encode => "javascript" # => <script type="text/javascript">eval(unescape('%64%6f%63...%6d%65%6e'))</script> mail_to "me@domain.com", "My email", :encode => "hex" # => <a href="mailto:%6d%65@%64%6f%6d%61%69%6e.%63%6f%6d">My email</a> mail_to "me@domain.com", nil, :replace_at => "_at_", :replace_dot => "_dot_", :class => "email" # => <a href="mailto:me@domain.com" class="email">me_at_domain_dot_com</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>
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 372 372: def mail_to(email_address, name = nil, html_options = {}) 373: html_options = html_options.stringify_keys 374: encode = html_options.delete("encode").to_s 375: cc, bcc, subject, body = html_options.delete("cc"), html_options.delete("bcc"), html_options.delete("subject"), html_options.delete("body") 376: 377: string = '' 378: extras = '' 379: extras << "cc=#{CGI.escape(cc).gsub("+", "%20")}&" unless cc.nil? 380: extras << "bcc=#{CGI.escape(bcc).gsub("+", "%20")}&" unless bcc.nil? 381: extras << "body=#{CGI.escape(body).gsub("+", "%20")}&" unless body.nil? 382: extras << "subject=#{CGI.escape(subject).gsub("+", "%20")}&" unless subject.nil? 383: extras = "?" << extras.gsub!(/&?$/,"") unless extras.empty? 384: 385: email_address = email_address.to_s 386: 387: email_address_obfuscated = email_address.dup 388: email_address_obfuscated.gsub!(/@/, html_options.delete("replace_at")) if html_options.has_key?("replace_at") 389: email_address_obfuscated.gsub!(/\./, html_options.delete("replace_dot")) if html_options.has_key?("replace_dot") 390: 391: if encode == "javascript" 392: tmp = "document.write('#{content_tag("a", name || email_address, html_options.merge({ "href" => "mailto:"+email_address+extras }))}');" 393: for i in 0...tmp.length 394: string << sprintf("%%%x",tmp[i]) 395: end 396: "<script type=\"#{Mime::JS}\">eval(unescape('#{string}'))</script>" 397: elsif encode == "hex" 398: email_address_encoded = '' 399: email_address_obfuscated.each_byte do |c| 400: email_address_encoded << sprintf("&#%d;", c) 401: end 402: 403: protocol = 'mailto:' 404: protocol.each_byte { |c| string << sprintf("&#%d;", c) } 405: 406: for i in 0...email_address.length 407: if email_address[i,1] =~ /\w/ 408: string << sprintf("%%%x",email_address[i]) 409: else 410: string << email_address[i,1] 411: end 412: end 413: content_tag "a", name || email_address_encoded, html_options.merge({ "href" => "#{string}#{extras}" }) 414: else 415: content_tag "a", name || email_address_obfuscated, html_options.merge({ "href" => "mailto:#{email_address}#{extras}" }) 416: end 417: end
Returns the URL for the set of options provided. This takes the same options as url_for in ActionController (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.
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).
<%= 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
# File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 65 65: def url_for(options = {}) 66: case options 67: when Hash 68: show_path = options[:host].nil? ? true : false 69: options = { :only_path => show_path }.update(options.symbolize_keys) 70: escape = options.key?(:escape) ? options.delete(:escape) : true 71: url = @controller.send(:url_for, options) 72: when String 73: escape = true 74: url = options 75: when NilClass 76: url = @controller.send(:url_for, nil) 77: else 78: escape = false 79: url = polymorphic_path(options) 80: end 81: 82: escape ? escape_once(url) : url 83: end