Fix slugged models with polymorphic relationships. Closes norman#65.

lib/friendly_id/active_record_adapter/configuration.rb

@@ -57,9 +57,11 @@ def autodiscover_cache_column
 
       def associated_friendly_classes
         configured_class.reflect_on_all_associations.select { |assoc|
-          assoc.klass.uses_friendly_id? }.map(&:klass)
+          !assoc.options[:polymorphic] &&
+          assoc.klass.uses_friendly_id?
+        }.map(&:klass)
       end
 
     end
   end
-end
+end

test/active_record_adapter/ar_test_helper.rb

@@ -105,4 +105,15 @@ class Novel < ::Book
 # A model with no table
 class Question < ActiveRecord::Base
   has_friendly_id :name, :use_slug => true
+end
+
+# A model to test polymorphic associations
+class Site < ActiveRecord::Base
+  belongs_to :owner, :polymorphic => true
+  has_friendly_id :name, :use_slug => true
+end
+
+# A model used as a polymorphic owner
+class Company < ActiveRecord::Base
+  has_many :sites, :as => :owner
 end

test/active_record_adapter/scoped_model_test.rb

@@ -17,6 +17,8 @@ def setup
         @canada = Country.create!(:name => "Canada")
         @resident = Resident.create!(:name => "John Smith", :country => @usa)
         @resident2 = Resident.create!(:name => "John Smith", :country => @canada)
+        @owner = Company.create!(:name => "Acme Events")
+        @site = Site.create!(:name => "Downtown Venue", :owner => @owner)
       end
 
       def teardown
@@ -105,6 +107,11 @@ def teardown
           assert_match(/scope: badscope/, e.message)
         end
       end
+
+      test "should update the sluggable field when a polymorphic relationship exists" do
+        @site.update_attributes(:name => "Uptown Venue")
+        assert_equal "Uptown Venue", @site.name
+      end
 
     end
   end

test/active_record_adapter/support/models.rb

@@ -71,6 +71,15 @@ def self.up
     end
     add_index :users, :name, :unique => true
 
+    create_table :sites do |t|
+      t.string :name
+      t.integer :owner_id
+      t.string :owner_type
+    end
+
+    create_table :companies do |t|
+      t.string :name
+    end
   end
 
   def self.down