Improved nested exposures performance, nested exposures doubling fixed

ruby-grape#57
ruby-grape#59

Author: AMar4enko

CHANGELOG.md

@@ -2,6 +2,8 @@ Next Release
 ============
 
 * Your contribution here.
+* [#60] (https://github.com/intridea/grape-entity/issues/59): Performance issues introduced by nested exposures - [@AlexYankee](https://github.com/AlexYankee).
+* [#60] (https://github.com/intridea/grape-entity/issues/57): Nested exposure double-exposes a field - [@AlexYankee](https://github.com/AlexYankee).
 
 0.4.1 (2014-02-13)
 ==================

lib/grape_entity/entity.rb

@@ -136,9 +136,13 @@ def self.expose(*args, &block)
       options[:proc] = block if block_given? && block.parameters.any?
 
       @nested_attributes ||= []
+
       args.each do |attribute|
         unless @nested_attributes.empty?
           attribute = "#{@nested_attributes.last}__#{attribute}"
+          options[:nested] = true
+          nested_exposures[@nested_attributes.last.to_sym] ||= {}
+          nested_exposures[@nested_attributes.last.to_sym][attribute.to_sym] = options
         end
 
         exposures[attribute.to_sym] = options
@@ -180,6 +184,16 @@ def self.exposures
       @exposures
     end
 
+    def self.nested_exposures
+      @nested_exposures ||= {}
+
+      if superclass.respond_to? :nested_exposures
+        @nested_exposures = superclass.nested_exposures.merge(@nested_exposures)
+      end
+
+      @nested_exposures
+    end
+
     # Returns a hash, the keys are symbolized references to fields in the entity,
     # the values are document keys in the entity's documentation key. When calling
     # #docmentation, any exposure without a documentation key will be ignored.
@@ -324,7 +338,7 @@ def exposures
     end
 
     def valid_exposures
-      exposures.select do |attribute, exposure_options|
+      exposures.reject { |a, options| options[:nested] }.select do |attribute, exposure_options|
         valid_exposure?(attribute, exposure_options)
       end
     end
@@ -390,7 +404,7 @@ def self.key_for(attribute)
     end
 
     def self.nested_exposures_for(attribute)
-      exposures.select { |a, _| a.to_s =~ /^#{attribute}__/ }
+      nested_exposures[attribute] || {}
     end
 
     def value_for(attribute, options = {})

spec/grape_entity/entity_spec.rb

@@ -92,9 +92,9 @@ class BogusEntity < Grape::Entity
 
             subject.exposures.should == {
               awesome: {},
-              awesome__nested: {},
-              awesome__nested__moar_nested: { as: 'weee' },
-              awesome__another_nested: { using: 'Awesome' }
+              awesome__nested: { nested: true },
+              awesome__nested__moar_nested: { as: 'weee', nested: true },
+              awesome__another_nested: { using: 'Awesome', nested: true }
             }
           end
 
@@ -110,6 +110,26 @@ class BogusEntity < Grape::Entity
             }
           end
 
+          it 'does not represent attributes, declared inside nested exposure, outside of it' do
+            subject.expose :awesome do
+              subject.expose(:nested) { |_| "value" }
+              subject.expose(:another_nested) { |_| "value" }
+              subject.expose :second_level_nested do
+                subject.expose(:deeply_exposed_attr) { |_| "value" }
+              end
+            end
+
+            subject.represent({}).serializable_hash.should == {
+              awesome: {
+                nested: "value",
+                another_nested: "value",
+                second_level_nested: {
+                    deeply_exposed_attr: "value"
+                }
+              }
+            }
+          end
+
           it 'is safe if its nested exposures are safe' do
             subject.with_options safe: true do
               subject.expose :awesome do
@@ -121,6 +141,7 @@ class BogusEntity < Grape::Entity
             end
 
             valid_keys = subject.represent({}).valid_exposures.keys
+
             valid_keys.include?(:awesome).should == true && \
             valid_keys.include?(:not_awesome).should == false
           end