Add the has_many_polymorphs plugin

[cs356-p2-videostore.git] / vendor / plugins / has_many_polymorphs / lib / has_many_polymorphs / reflection.rb

diff --git a/vendor/plugins/has_many_polymorphs/lib/has_many_polymorphs/reflection.rb b/vendor/plugins/has_many_polymorphs/lib/has_many_polymorphs/reflection.rb
new file mode 100644 (file)
index 0000000..3a8d537
--- /dev/null
+++ b/vendor/plugins/has_many_polymorphs/lib/has_many_polymorphs/reflection.rb
@@ -0,0 +1,57 @@
+module ActiveRecord #:nodoc:
+  module Reflection #:nodoc:
+    
+    module ClassMethods #:nodoc:
+  
+      # Update the default reflection switch so that <tt>:has_many_polymorphs</tt> types get instantiated. It's not a composed method so we have to override the whole thing.
+      def create_reflection(macro, name, options, active_record)
+        case macro
+          when :has_many, :belongs_to, :has_one, :has_and_belongs_to_many
+            reflection = AssociationReflection.new(macro, name, options, active_record)
+          when :composed_of
+            reflection = AggregateReflection.new(macro, name, options, active_record)
+        # added by has_many_polymorphs #
+          when :has_many_polymorphs
+            reflection = PolymorphicReflection.new(macro, name, options, active_record)
+        # end added #
+        end
+        write_inheritable_hash :reflections, name => reflection
+        reflection
+      end
+      
+    end
+
+    class PolymorphicError < ActiveRecordError #:nodoc:
+    end
+    
+=begin rdoc
+
+The reflection built by the <tt>has_many_polymorphs</tt> method. 
+
+Inherits from ActiveRecord::Reflection::AssociationReflection.
+
+=end
+
+    class PolymorphicReflection < AssociationReflection
+      # Stub out the validity check. Has_many_polymorphs checks validity on macro creation, not on reflection.
+      def check_validity! 
+        # nothing
+      end                 
+
+      # Return the source reflection.
+      def source_reflection
+        # normally is the has_many to the through model, but we return ourselves, 
+        # since there isn't a real source class for a polymorphic target
+        self
+      end      
+      
+      # Set the classname of the target. Uses the join class name.
+      def class_name
+        # normally is the classname of the association target
+        @class_name ||= options[:join_class_name]
+      end
+                     
+    end
+ 
+  end
+end