method

polymorphic_url

v2.0.3 - Show latest stable - Class: ActionController::PolymorphicRoutes

polymorphic_url(record_or_hash_or_array, options = {})

public

Constructs a call to a named RESTful route for the given record and returns the resulting URL string. For example:

  polymorphic_url(post)
  # calls post_url(post) #=> "http://example.com/posts/1"

Options

:action — specifies the action prefix for the named route: :new, :edit or :formatted. Default is no prefix.
:routing_type — :path or :url (default :url).

Examples

  # an Article record
  polymorphic_url(record)  #->  article_url(record)

  # a Comment record
  polymorphic_url(record)  #->  comment_url(record)

  # it recognizes new records and maps to the collection
  record = Comment.new
  polymorphic_url(record)  #->  comments_url()

# File actionpack/lib/action_controller/polymorphic_routes.rb, line 70
    def polymorphic_url(record_or_hash_or_array, options = {})
      record    = extract_record(record_or_hash_or_array)
      format    = (options[:action].to_s == "formatted" and record_or_hash_or_array.pop)
      namespace = extract_namespace(record_or_hash_or_array)
      
      args = case record_or_hash_or_array
        when Hash;  [ record_or_hash_or_array ]
        when Array; record_or_hash_or_array.dup
        else        [ record_or_hash_or_array ]
      end

      args << format if format

      inflection =
        case
        when options[:action].to_s == "new"
          args.pop
          :singular
        when record.respond_to?(:new_record?) && record.new_record?
          args.pop
          :plural
        else
          :singular
        end
      
      named_route = build_named_route_call(record_or_hash_or_array, namespace, inflection, options)
      send!(named_route, *args)
    end

3Notes

Universal partial

hosiawak · Jan 13, 20097 thanks

polymorphic_url is very useful if you want to create an universal partial that works for more than 1 type of object passed to it.

For example in you sidebar you might have a _sidebar.html.erb partial that's supposed to display links to "Edit" and "Delete" actions. You can write it in such a way that it can be reused for different types of objects (in the example below we pass either a Post or a Note).

your_template.html.erb <%= render :partial => 'shared/sidebar', :locals => { :obj => Post.new -%>

other_template.html.erb <%= render :partial => 'shared/sidebar', :locals => { :obj => Note.new -%>

_sidebar.html.erb <%= link_to "Edit", polymorhpic_url(obj, :action => 'edit') -%> <%= link_to "Delete", polymorphic_url(obj), :method => :delete -%>

Easier Universal Partials

eric_programmer · Jan 13, 20092 thanks

@hosiawak provides a great example of how to use polymorphic_path to produce universal partials. You can actually simply his example even more with the following:

<%= link_to 'Edit', edit_polymorphic_path(obj) %> <%= link_to 'Delete', obj, :method => :delete %>

So the things to note are that in addition to polymorphic_path, Rails also provides an "edit_" version just like on your resources so you can use that instead of specifying the action specifically. The second thing to remember is if you pass just the raw object as the path then then rails will automatically wrap it in a call to polymorphic_path.

Anchor option

tokland · Sep 29, 20101 thank

It's not documented, but :anchor is an option.

polymorphic_path(commentable, :anchor => 'comments')

will return:

/article/1#comments