Module | ActionView::Helpers::UrlHelper
In: | lib/action_view/helpers/url_helper.rb

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

button_to current_page? link_image_to link_to link_to_if link_to_image link_to_unless link_to_unless_current mail_to url_for

### Included Modules

JavaScriptHelper

### Public Instance methods

button_to(name, options = {}, html_options = nil)

Generates a form containing a sole button that submits to the URL given by options. Use this method instead of `link_to` for actions that do not have the safe HTTP GET semantics implied by using a hypertext link.

The parameters are the same as for `link_to`. Any html_options that you pass will be applied to the inner `input` element. In particular, pass

      :disabled => true/false

as part of html_options to control whether the button is disabled. The generated form element is given the class ‘button-to’, to which you can attach CSS styles for display purposes.

Example 1:

      # inside of controller for "feeds"
      button_to "Edit", :action => 'edit', :id => 3

Generates the following HTML (sans formatting):

      <form method="post" action="/feeds/edit/3" class="button-to">
        <div><input value="Edit" type="submit" /></div>
      </form>

Example 2:

      button_to "Destroy", { :action => 'destroy', :id => 3 },
                :confirm => "Are you sure?"

Generates the following HTML (sans formatting):

      <form method="post" action="/feeds/destroy/3" class="button-to">
        <div><input onclick="return confirm('Are you sure?');"
                    value="Destroy" type="submit" />
        </div>
      </form>

NOTE: This method generates HTML code that represents a form. Forms are "block" content, which means that you should not try to insert them into your HTML where only inline content is expected. For example, you can legally insert a form inside of a `div` or `td` element or in between `p` elements, but not in the middle of a run of text, nor can you place a form within another form. (Bottom line: Always validate your HTML before going public.)

current_page?(options)

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

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")

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 the documentation for ActionController::Base#url_for. 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 has three special features. One 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.

Another for creating a popup window, which is done by either passing :popup with true or the options of the window in Javascript form.

And a third for making the link do a POST request (instead of the regular GET) through a dynamically added form element that is instantly submitted. Note that if the user has turned off Javascript, the request will fall back on the GET. So its your responsibility to determine what the action should be once it arrives at the controller. The POST form is turned on by passing :post as true. Note, it’s not possible to use POST requests and popup targets at the same time (an exception will be thrown).

Examples:

      link_to "Delete this page", { :action => "destroy", :id => @page.id }, :confirm => "Are you sure?"
      link_to "Help", { :action => "help" }, :popup => true
      link_to "Busy loop", { :action => "busy" }, :popup => ['new_window', 'height=300,width=600']
      link_to "Destroy account", { :action => "destroy" }, :confirm => "Are you sure?", :post => true

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).

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).

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.

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>

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 documentation for ActionController::Base#url_for. Note that it’ll set :only_path => true so you’ll get /controller/action instead of the example.com/controller/action part (makes it harder to parse httpd log files)

When called from a view, url_for returns an HTML escaped url. If you need an unescaped url, pass :escape => false to url_for.

[Validate]