Provides a set of methods for making easy links and getting urls that depend on the controller and action. This means that you can use the same format for links in the views that you do in the controller. The different methods are even named synchronously, so link_to uses that same url as is generated by url_for, which again is the same url used for redirection in redirect_to.

Methods
Public Instance methods
current_page?(options)

Returns true if the current page uri is generated by the options passed (in url_for format).

[ show source ]

     # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 150
150:       def current_page?(options)
151:         url_for(options) == @request.request_uri
152:       end
link_image_to(src, options = {}, html_options = {}, *parameters_for_method_reference)

This tag is deprecated. Combine the link_to and AssetTagHelper::image_tag yourself instead, like: 

  link_to(image_tag("rss", :size => "30x45", :border => 0), "http://www.example.com")
This method is also aliased as link_to_image

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 38
38:       def link_image_to(src, options = {}, html_options = {}, *parameters_for_method_reference)
39:         image_options = { "src" => src.include?("/") ? src : "/images/#{src}" }
40:         image_options["src"] += ".png" unless image_options["src"].include?(".")
41: 
42:         html_options = html_options.stringify_keys
43:         if html_options["alt"]
44:           image_options["alt"] = html_options["alt"]
45:           html_options.delete "alt"
46:         else
47:           image_options["alt"] = src.split("/").last.split(".").first.capitalize
48:         end
49: 
50:         if html_options["size"]
51:           image_options["width"], image_options["height"] = html_options["size"].split("x")
52:           html_options.delete "size"
53:         end
54: 
55:         if html_options["border"]
56:           image_options["border"] = html_options["border"]
57:           html_options.delete "border"
58:         end
59: 
60:         if html_options["align"]
61:           image_options["align"] = html_options["align"]
62:           html_options.delete "align"
63:         end
64: 
65:         link_to(tag("img", image_options), options, html_options, *parameters_for_method_reference)
66:       end
link_to(name, options = {}, html_options = nil, *parameters_for_method_reference)

Creates a link tag of the given name using an URL created by the set of options. See the valid options in classes/ActionController/Base.html#M000021. It’s also possible to pass a string instead of an options hash to get a link tag that just points without consideration. If nil is passed as a name, the link itself will become the name. The html_options have a special feature for creating javascript confirm alerts where if you pass :confirm => ‘Are you sure?’, the link will be guarded with a JS popup asking that question. If the user accepts, the link is processed, otherwise not.

Example: 

  link_to "Delete this page", { :action => "destroy", :id => @page.id }, :confirm => "Are you sure?"

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 23
23:       def link_to(name, options = {}, html_options = nil, *parameters_for_method_reference)
24:         html_options = (html_options || {}).stringify_keys
25:         convert_confirm_option_to_javascript!(html_options)
26:         if options.is_a?(String)
27:           content_tag "a", name || options, (html_options || {}).merge("href" => options)
28:         else
29:           content_tag(
30:             "a", name || url_for(options, *parameters_for_method_reference),
31:             (html_options || {}).merge("href" => url_for(options, *parameters_for_method_reference))
32:           )
33:         end
34:       end
link_to_if(condition, name, options = {}, html_options = {}, *parameters_for_method_reference, &block)

Create a link tag of the given name using an URL created by the set of options, if condition is true, in which case only the name is returned (or the given block is yielded, if one exists).

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 94
94:       def link_to_if(condition, name, options = {}, html_options = {}, *parameters_for_method_reference, &block)
95:         link_to_unless !condition, name, options, html_options, *parameters_for_method_reference, &block
96:       end
link_to_image(src, options = {}, html_options = {}, *parameters_for_method_reference)

Alias for link_image_to

link_to_unless(condition, name, options = {}, html_options = {}, *parameters_for_method_reference) {|name| ...}

Create a link tag of the given name using an URL created by the set of options, unless condition is true, in which case only the name is returned (or the given block is yielded, if one exists).

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 80
80:       def link_to_unless(condition, name, options = {}, html_options = {}, *parameters_for_method_reference, &block)
81:         if condition
82:           if block_given?
83:             block.arity <= 1 ? yield(name) : yield(name, options, html_options, *parameters_for_method_reference)
84:           else
85:             html_escape(name)
86:           end
87:         else
88:           link_to(name, options, html_options, *parameters_for_method_reference)
89:         end  
90:       end
link_to_unless_current(name, options = {}, html_options = {}, *parameters_for_method_reference, &block)

Creates a link tag of the given name using an URL created by the set of options, unless the current request uri is the same as the link’s, in which case only the name is returned (or the given block is yielded, if one exists). This is useful for creating link bars where you don’t want to link to the page currently being viewed.

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 74
74:       def link_to_unless_current(name, options = {}, html_options = {}, *parameters_for_method_reference, &block)
75:         link_to_unless current_page?(options), name, options, html_options, *parameters_for_method_reference, &block
76:       end
mail_to(email_address, name = nil, html_options = {})

Creates a link tag for starting an email to the specified email_address, which is also used as the name of the link unless name is specified. Additional HTML options, such as class or id, can be passed in the html_options hash.

You can also make it difficult for spiders to harvest email address by obfuscating them. Examples: 

  mail_to "me@domain.com", "My email", :encode => "javascript"  # =>
    <script type="text/javascript" language="javascript">eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%64%6f%6d%61%69%6e%2e%63%6f%6d%22%3e%4d%79%20%65%6d%61%69%6c%3c%2f%61%3e%27%29%3b'))</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>

You can also specify the cc address, bcc address, subject, and body parts of the message header to create a complex e-mail using the corresponding cc, bcc, subject, and body html_options keys. Each of these options are URI escaped and then appended to the email_address before being output. Be aware that javascript keywords will not be escaped and may break this feature when encoding with javascript. Examples: 

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

[ show source ]

     # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 116
116:       def mail_to(email_address, name = nil, html_options = {})
117:         html_options = html_options.stringify_keys
118:         encode = html_options.delete("encode")
119:         cc, bcc, subject, body = html_options.delete("cc"), html_options.delete("bcc"), html_options.delete("subject"), html_options.delete("body")
120: 
121:         string = ''
122:         extras = ''
123:         extras << "cc=#{CGI.escape(cc).gsub("+", "%20")}&" unless cc.nil?
124:         extras << "bcc=#{CGI.escape(bcc).gsub("+", "%20")}&" unless bcc.nil?
125:         extras << "body=#{CGI.escape(body).gsub("+", "%20")}&" unless body.nil?
126:         extras << "subject=#{CGI.escape(subject).gsub("+", "%20")}&" unless subject.nil?
127:         extras = "?" << extras.gsub!(/&?$/,"") unless extras.empty?
128: 
129:         if encode == 'javascript'
130:           tmp = "document.write('#{content_tag("a", name || email_address, html_options.merge({ "href" => "mailto:"+email_address.to_s+extras }))}');"
131:           for i in 0...tmp.length
132:             string << sprintf("%%%x",tmp[i])
133:           end
134:           "<script type=\"text/javascript\" language=\"javascript\">eval(unescape('#{string}'))</script>"
135:         elsif encode == 'hex'
136:           for i in 0...email_address.length
137:             if email_address[i,1] =~ /\w/
138:               string << sprintf("%%%x",email_address[i])
139:             else
140:               string << email_address[i,1]
141:             end
142:           end
143:           content_tag "a", name || email_address, html_options.merge({ "href" => "mailto:#{string}#{extras}" })
144:         else
145:           content_tag "a", name || email_address, html_options.merge({ "href" => "mailto:#{email_address}#{extras}" })
146:         end
147:       end
url_for(options = {}, *parameters_for_method_reference)

Returns the URL for the set of options provided. This takes the same options as url_for. For a list, see the url_for documentation in classes/ActionController/Base.html#M000079.

[ show source ]

    # File vendor/rails/actionpack/lib/action_view/helpers/url_helper.rb, line 10
10:       def url_for(options = {}, *parameters_for_method_reference)
11:         options = { :only_path => true }.update(options.symbolize_keys) if options.kind_of? Hash
12:         @controller.send(:url_for, options, *parameters_for_method_reference)
13:       end