Makes decorates_association work transparently with Plain Old Ruby Objects.

lib/draper/base.rb

@@ -64,15 +64,21 @@ module Draper
     def self.decorates_association(association_symbol, options = {})
       define_method(association_symbol) do
         orig_association = model.send(association_symbol)
+
         return orig_association if orig_association.nil?
-        if options[:with]
-          options[:with].decorate(orig_association)
-        elsif options[:polymorphic]
-          "#{orig_association.class}Decorator".constantize.decorate(orig_association)
+
+        return options[:with].decorate(orig_association) if options[:with]
+
+        if options[:polymorphic]
+          klass = orig_association.class
+        elsif model.class.respond_to?(:reflect_on_association) && model.class.reflect_on_association(association_symbol)
+          klass = model.class.reflect_on_association(association_symbol).klass
+        elsif orig_association.respond_to?(:first)
+          klass = orig_association.first.class
         else
-          reflection = model.class.reflect_on_association(association_symbol)
-          "#{reflection.klass}Decorator".constantize.decorate(orig_association, options)
+          klass = orig_association.class
         end
+        "#{klass}Decorator".constantize.decorate(orig_association, options)
       end
     end
 

spec/draper/base_spec.rb

@@ -113,22 +113,31 @@ describe Draper::Base do
   end
 
   context(".decorates_association") do
-    context "for collection associations" do
+    context "for ActiveModel collection associations" do
       before(:each){ subject.class_eval{ decorates_association :similar_products } }
       it "causes the association's method to return a collection of wrapped objects" do
         subject.similar_products.each{ |decorated| decorated.should be_instance_of(ProductDecorator) }
       end
     end
 
-    context "for a singular association" do
+    context "for Plain Old Ruby Object collection associations" do
+      before(:each){ subject.class_eval{ decorates_association :poro_similar_products } }
+      it "causes the association's method to return a collection of wrapped objects" do
+        subject.poro_similar_products.each{ |decorated| decorated.should be_instance_of(ProductDecorator) }
+      end
+    end
+
+    context "for an ActiveModel singular association" do
       before(:each){ subject.class_eval{ decorates_association :previous_version } }
       it "causes the association's method to return a single wrapped object if the association is singular" do
         subject.previous_version.should be_instance_of(ProductDecorator)
       end
+    end
 
-      it "causes the association's method to return nil if the association is nil" do
-        source.stub(:previous_version){ nil }
-        subject.previous_version.should be_nil
+    context "for a Plain Old Ruby Object singular association" do
+      before(:each){ subject.class_eval{ decorates_association :poro_previous_version } }
+      it "causes the association's method to return a single wrapped object" do
+        subject.poro_previous_version.should be_instance_of(ProductDecorator)
       end
     end
 
@@ -145,6 +154,16 @@ describe Draper::Base do
         subject.thing.should be_instance_of(SomeThingDecorator)
       end
     end
+
+    context "when the association is nil" do
+      before(:each) do
+        subject.class_eval{ decorates_association :previous_version }
+        source.stub(:previous_version){ nil }
+      end
+      it "causes the association's method to return nil" do
+        subject.previous_version.should be_nil
+      end
+    end
   end
 
   context('.decorates_associations') do

spec/support/samples/product.rb

@@ -54,7 +54,7 @@ class Product < ActiveRecord::Base
   end
 
   def self.reflect_on_association(association_symbol)
-    OpenStruct.new(:klass => self)
+    association_symbol.to_s.starts_with?("poro") ? nil : OpenStruct.new(:klass => self)
   end
 
   def similar_products
@@ -68,4 +68,13 @@ class Product < ActiveRecord::Base
   def thing
     SomeThing.new
   end
+
+  def poro_similar_products
+    [Product.new, Product.new]
+  end
+
+  def poro_previous_version
+    Product.new
+  end
+
 end