Merge pull request #327 from subvertallchris/rails4-cache_key

adds cache_key support for rails

lib/neo4j/rails/attributes.rb

@@ -126,6 +126,12 @@ def to_param
         persisted? ? neo_id.to_s : nil
       end
 
+      def cache_key
+        return "#{self.class.model_name.cache_key}/new" if new_record?
+        return "#{self.class.model_name.cache_key}/#{id}-#{self.updated_at.utc.to_s(:number)}" if self.respond_to?(:updated_at) && !self.updated_at.blank?
+        "#{self.class.model_name.cache_key}/#{id}"
+      end
+
       def to_model
         self
       end

spec/fixture/ice_cream.rb

@@ -8,3 +8,10 @@ class IceCream < Neo4j::Rails::Model
   validates_presence_of :flavour
 end
 
+class IceCreamStamp < Neo4j::Rails::Model
+  property :flavour, :index => :exact
+  property :created_at, type: DateTime
+  property :updated_at, type: DateTime
+  has_n(:ingredients).to(Ingredient)
+  validates_presence_of :flavour
+end

spec/integration/model_spec.rb

@@ -169,7 +169,6 @@ class ::Property < Neo4j::Rails::Model
     end
   end
 
-
   describe "error" do
     it "the validation method 'errors' returns the validation errors" do
       p = IceCream.new
@@ -181,6 +180,32 @@ class ::Property < Neo4j::Rails::Model
     end
   end
 
+  describe "cache_key method" do
+    describe "unpersisted object" do
+      it "should respond with plural_model/new" do
+        model = IceCreamStamp.new
+        model.cache_key.should eq 'ice_cream_stamps/new'
+      end
+    end
+
+    describe "persisted object" do
+      it "should respond with a valid cache key" do
+        model = IceCreamStamp.create(flavour: "vanilla")
+        #model.flavour = "chocolate" and model.save
+        model.cache_key.should eq "ice_cream_stamps/#{model.id}-#{model.updated_at.utc.to_s(:number)}"
+      end
+
+      context "when changed" do
+        it "should change cache_key value" do
+          model = IceCreamStamp.create(flavour: "vanilla")
+          start = model.cache_key and sleep 1
+          model.flavour = "chocolate" and model.save
+          model.cache_key.should_not eq start
+        end
+      end
+    end
+  end
+
   describe "ActiveModel::Dirty" do
 
     it "implements attribute_changed?, _change, _changed, _was, _changed? methods" do