1 files changed, 21 insertions, 18 deletions
diff --git a/actionpack/lib/action_view/renderer/partial_renderer.rb b/actionpack/lib/action_view/renderer/partial_renderer.rb
index 54a0ba96ff..374bdb62f5 100644
--- a/actionpack/lib/action_view/renderer/partial_renderer.rb
+++ b/actionpack/lib/action_view/renderer/partial_renderer.rb
@@ -82,16 +82,18 @@ module ActionView
   #
   # This will render the partial "advertisement/_ad.html.erb" regardless of which controller this is being called from.
   #
-  # == Rendering objects with the RecordIdentifier
+  # == Rendering objects that respond to `to_partial_path`
   #
-  # Instead of explicitly naming the location of a partial, you can also let the RecordIdentifier do the work if
-  # you're following its conventions for RecordIdentifier#partial_path. Examples:
+  # Instead of explicitly naming the location of a partial, you can also let PartialRenderer do the work
+  # and pick the proper path by checking `to_proper_path` method. If the object passed to render is a collection,
+  # all objects must return the same path.
   #
-  #  # @account is an Account instance, so it uses the RecordIdentifier to replace
+  #  # @account.to_partial_path returns 'accounts/account', so it can be used to replace:
   #  # <%= render :partial => "accounts/account", :locals => { :account => @account} %>
   #  <%= render :partial => @account %>
   #
-  #  # @posts is an array of Post instances, so it uses the RecordIdentifier to replace
+  #  # @posts is an array of Post instances, so every post record returns 'posts/post' on `to_partial_path`,
+  #  # that's why we can replace:
   #  # <%= render :partial => "posts/post", :collection => @posts %>
   #  <%= render :partial => @posts %>
   #
@@ -106,13 +108,14 @@ module ActionView
   #  # Instead of <%= render :partial => "account", :locals => { :account => @buyer } %>
   #  <%= render "account", :account => @buyer %>
   #
-  #  # @account is an Account instance, so it uses the RecordIdentifier to replace
-  #  # <%= render :partial => "accounts/account", :locals => { :account => @account } %>
-  #  <%= render(@account) %>
+  #  # @account.to_partial_path returns 'accounts/account', so it can be used to replace:
+  #  # <%= render :partial => "accounts/account", :locals => { :account => @account} %>
+  #  <%= render @account %>
   #
-  #  # @posts is an array of Post instances, so it uses the RecordIdentifier to replace
+  #  # @posts is an array of Post instances, so every post record returns 'posts/post' on `to_partial_path`,
+  #  # that's why we can replace:
   #  # <%= render :partial => "posts/post", :collection => @posts %>
-  #  <%= render(@posts) %>
+  #  <%= render @posts %>
   #
   # == Rendering partials with layouts
   #
@@ -205,7 +208,7 @@ module ActionView
   #       Deadline: <%= user.deadline %>
   #     <%- end -%>
   #   <% end %>
-  class PartialRenderer < AbstractRenderer #:nodoc:
+  class PartialRenderer < AbstractRenderer
     PARTIAL_NAMES = Hash.new { |h,k| h[k] = {} }
 
     def initialize(*)
@@ -375,23 +378,23 @@ module ActionView
         end
       end
 
-      @partial_names[path] ||= path.dup.tap do |object_path|
-        merge_prefix_into_object_path(@context_prefix, object_path)
-      end
+      @partial_names[path] ||= merge_prefix_into_object_path(@context_prefix, path.dup)
     end
 
     def merge_prefix_into_object_path(prefix, object_path)
       if prefix.include?(?/) && object_path.include?(?/)
-        overlap = []
+        prefixes = []
         prefix_array = File.dirname(prefix).split('/')
         object_path_array = object_path.split('/')[0..-3] # skip model dir & partial
 
         prefix_array.each_with_index do |dir, index|
-          overlap << dir if dir == object_path_array[index]
+          break if dir == object_path_array[index]
+          prefixes << dir
         end
 
-        object_path.gsub!(/^#{overlap.join('/')}\//,'')
-        object_path.insert(0, "#{File.dirname(prefix)}/")
+        (prefixes << object_path).join("/")
+      else
+        object_path
       end
     end