method

polymorphic_url

rails 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:

  # calls post_url(post)
  polymorphic_url(post) # => "http://example.com/posts/1"
  polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
  polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
  polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"

Options

:action - Specifies the action prefix for the named route: :new or :edit. Default is no prefix.
:routing_type - Allowed values are :path or :url. Default is :url.

Examples

  # an Article record
  polymorphic_url(record)  # same as article_url(record)

  # a Comment record
  polymorphic_url(record)  # same as comment_url(record)

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

# File actionpack/lib/action_controller/polymorphic_routes.rb, line 73
    def polymorphic_url(record_or_hash_or_array, options = {})
      if record_or_hash_or_array.kind_of?(Array)
        record_or_hash_or_array = record_or_hash_or_array.compact
        record_or_hash_or_array = record_or_hash_or_array[0] if record_or_hash_or_array.size == 1
      end

      record = extract_record(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

      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

      args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}
      named_route = build_named_route_call(record_or_hash_or_array, inflection, options)

      url_options = options.except(:action, :routing_type)
      unless url_options.empty?
        args.last.kind_of?(Hash) ? args.last.merge!(url_options) : args << url_options
      end

      __send__(named_route, *args)
    end

4Notes

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 -%>

polymorphic_url and namespaces and nested resources

GhandaL · Aug 12, 20085 thanks

You can use polymorphic_url with namespaces and nested resources using array as parameter: polymorphic_url([:admin, @post]) will return: admin_post_url(@post)

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