Ruby on Rails latest stable (v4.0.2) - 6 notes - Class: ActionController::PolymorphicRoutes

Method deprecated or moved

This method is deprecated or moved on the latest stable version. The last existing version (v2.3.8) is shown here.

These similar methods exist in v4.0.2:

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"


  • :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.


  # 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()
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January 13, 2009
6 thanks

Universal partial

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).


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


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


<%= link_to "Edit", polymorhpic_url(obj, :action => 'edit') -%>
<%= link_to "Delete", polymorphic_url(obj), :method => :delete -%>
August 12, 2008 - (>= v2.1.0)
4 thanks

polymorphic_url and namespaces and nested resources

You can use polymorphic_url with namespaces and nested resources using array as parameter:

polymorphic_url([:admin, @post])

will return:

January 13, 2009
2 thanks

Easier Universal Partials

@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.

September 29, 2010
1 thank

Anchor option

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

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

will return:

July 28, 2008 - (v2.1.0)
0 thanks

Bug? does not encode options

polymorphic_path(item,options) =polymorphic_path(item)+hash_to_url_query(options)

def hash_to_url_query(hash)
  url = []
  hash.each{|k,v| url << "#{k}=#{v}"}
  "=" + (url * '&')