2 files changed, 59 insertions, 5 deletions
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index 8cdd3d2fe8..a860388bae 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -3,18 +3,36 @@ require 'active_support/inflector'
 module ActiveModel
 
   class Name < String
-    attr_reader :singular, :plural, :element, :collection, :partial_path
-    alias_method :cache_key, :collection
+    attr_reader :singular, :plural, :element
 
     def initialize(klass)
       super(klass.name)
       @klass = klass
       @singular = ActiveSupport::Inflector.underscore(self).tr('/', '_').freeze
       @plural = ActiveSupport::Inflector.pluralize(@singular).freeze
-      @element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(self)).freeze
+      @collection = nil
+      self.element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(self)).freeze
+    end
+
+    def element=(element)
+      @element = element
       @human = ActiveSupport::Inflector.humanize(@element).freeze
-      @collection = ActiveSupport::Inflector.tableize(self).freeze
-      @partial_path = "#{@collection}/#{@element}".freeze
+      @default_collection = nil
+      @partial_path = nil
+    end
+
+    def collection
+      @collection || default_collection
+    end
+    alias_method :cache_key, :collection
+
+    def collection=(collection)
+      @collection = collection
+      @partial_path = nil
+    end
+
+    def partial_path
+      @partial_path ||= "#{collection}/#{@element}"
     end
 
     # Transform the model name into a more humane format, using I18n. By default,
@@ -34,6 +52,12 @@ module ActiveModel
       options.reverse_merge! :scope => [@klass.i18n_scope, :models], :count => 1, :default => defaults
       I18n.translate(defaults.shift, options)
     end
+
+    private
+
+      def default_collection
+        @default_collection ||= ActiveSupport::Inflector.tableize(self.sub(/[^:]*$/, @element)).freeze
+      end
   end
 
   # ActiveModel::Naming is a module that creates a +model_name+ method on your
diff --git a/activemodel/test/cases/naming_test.rb b/activemodel/test/cases/naming_test.rb
index dc39b84ed8..3918002360 100644
--- a/activemodel/test/cases/naming_test.rb
+++ b/activemodel/test/cases/naming_test.rb
@@ -18,6 +18,26 @@ class NamingTest < ActiveModel::TestCase
     assert_equal 'track_back', @model_name.element
   end
 
+  def test_set_element
+    @model_name.element = 'foo'
+
+    assert_equal 'foo', @model_name.element
+    assert_equal 'Foo', @model_name.human
+    assert_equal 'post/foos', @model_name.collection
+    assert_equal 'post/foos/foo', @model_name.partial_path
+  end
+
+  def test_human
+    assert_equal 'Track back', @model_name.human
+  end
+
+  def test_set_collection
+    @model_name.collection = 'foo'
+
+    assert_equal 'foo', @model_name.collection
+    assert_equal 'foo/track_back', @model_name.partial_path
+  end
+
   def test_collection
     assert_equal 'post/track_backs', @model_name.collection
   end
@@ -25,4 +45,14 @@ class NamingTest < ActiveModel::TestCase
   def test_partial_path
     assert_equal 'post/track_backs/track_back', @model_name.partial_path
   end
+
+  def test_should_preserve_custom_collection
+    @model_name.collection = 'bar'
+    @model_name.element = 'foo'
+
+    assert_equal 'foo', @model_name.element
+    assert_equal 'Foo', @model_name.human
+    assert_equal 'bar', @model_name.collection
+    assert_equal 'bar/foo', @model_name.partial_path
+  end
 end