Added except option.

Author: dan-corneanu

CHANGELOG.md

@@ -5,6 +5,7 @@
 * [#115](https://github.com/intridea/grape-entity/pull/115): Allowing 'root' to be inherited from parent to child entities - [@guidoprincess](https://github.com/guidoprincess).
 * [#121](https://github.com/intridea/grape-entity/pull/122): Sublcassed Entity#documentation properly handles unexposed params - [@dan-corneanu](https://github.com/dan-corneanu).
 * [#134](https://github.com/intridea/grape-entity/pull/134): Subclasses no longer affected in all cases by `unexpose` in parent - [@etehtsea](https://github.com/etehtsea).
+* [#135](https://github.com/intridea/grape-entity/pull/135): Added `except` option - [@dan-corneanu](https://github.com/dan-corneanu).
 * Your contribution here.
 
 0.4.5 (2015-03-10)

README.md

@@ -222,7 +222,7 @@ end
 
 #### Returning only the fields you want
 
-After exposing the desired attributes, you can choose which one you need when representing some object or collection, see the example:
+After exposing the desired attributes, you can choose which one you need when representing some object or collection by using the only: and except: options. See the example:
 
 ```ruby
 class UserEntity
@@ -237,7 +237,7 @@ class Entity
   expose :user, using: UserEntity
 end
 
-data = Entity.represent(model, only: [:name, { user: [:name, :email] }])
+data = Entity.represent(model, only: [:title, { user: [:name, :email] }])
 data.as_json
 ```
 
@@ -256,7 +256,12 @@ This will return something like this:
 Instead of returning all the exposed attributes.
 
 
+The same result can be achieved with the following exposure:
 
+```ruby
+data = Entity.represent(model, except: [:id, { user: [:id] }])
+data.as_json
+```
 
 #### Aliases
 

lib/grape_entity/entity.rb

@@ -355,6 +355,7 @@ def self.present_collection(present_collection = false, collection_name = :items
     # @option options :serializable [true or false] when true a serializable Hash will be returned
     #
     # @option options :only [Array] all the fields that should be returned
+    # @option options :except [Array] all the fields that should not be returned
     def self.represent(objects, options = {})
       if objects.respond_to?(:to_ary) && ! @present_collection
         root_element =  root_element(:collection_root)
@@ -444,8 +445,12 @@ def serializable_hash(runtime_options = {})
     end
 
     def should_return_attribute?(attribute, options)
-      return true unless options[:only]
-      only_fields(options).include?(self.class.key_for(attribute))
+      key = self.class.key_for(attribute)
+      only = only_fields(options).nil? ||
+             only_fields(options).include?(key)
+      except = except_fields(options) && except_fields(options).include?(key) &&
+               except_fields(options)[key] == true
+      only && !except
     end
 
     def only_fields(options, for_attribute = nil)
@@ -469,6 +474,27 @@ def only_fields(options, for_attribute = nil)
       end
     end
 
+    def except_fields(options, for_attribute = nil)
+      return nil unless options[:except]
+
+      @except_fields ||= options[:except].each_with_object({}) do |attribute, allowed_fields|
+        if attribute.is_a?(Hash)
+          attribute.each do |attr, nested_attrs|
+            allowed_fields[attr] ||= []
+            allowed_fields[attr] += nested_attrs
+          end
+        else
+          allowed_fields[attribute] = true
+        end
+      end
+
+      if for_attribute && @except_fields[for_attribute].is_a?(Array)
+        @except_fields[for_attribute]
+      elsif for_attribute.nil?
+        @except_fields
+      end
+    end
+
     alias_method :as_json, :serializable_hash
 
     def to_json(options = {})
@@ -604,6 +630,7 @@ def options_for_using(attribute, options)
       using_options.delete(:collection)
       using_options[:root] = nil
       using_options[:only] = only_fields(using_options, attribute)
+      using_options[:except] = except_fields(using_options, attribute)
 
       using_options
     end

spec/grape_entity/entity_spec.rb

@@ -503,7 +503,21 @@ class Parent < Person
           expect(representation).to eq(id: nil, name: nil)
         end
 
-        it 'can specify children attributes' do
+        it 'returns all fields except the ones specified in the except option' do
+          subject.expose(:id, :name, :phone)
+          representation = subject.represent(OpenStruct.new, except: [:phone], serializable: true)
+          expect(representation).to eq(id: nil, name: nil)
+        end
+
+        it 'returns only fields specified in the only option and not specified in the except option' do
+          subject.expose(:id, :name, :phone)
+          representation = subject.represent(OpenStruct.new,
+                                             only: [:name, :phone],
+                                             except: [:phone], serializable: true)
+          expect(representation).to eq(name: nil)
+        end
+
+        it 'can specify children attributes with only' do
           user_entity = Class.new(Grape::Entity)
           user_entity.expose(:id, :name, :email)
 
@@ -514,16 +528,50 @@ class Parent < Person
           expect(representation).to eq(id: nil, name: nil, user: { name: nil, email: nil })
         end
 
+        it 'can specify children attributes with except' do
+          user_entity = Class.new(Grape::Entity)
+          user_entity.expose(:id, :name, :email)
+
+          subject.expose(:id, :name, :phone)
+          subject.expose(:user, using: user_entity)
+
+          representation = subject.represent(OpenStruct.new(user: {}), except: [:phone, { user: [:id] }], serializable: true)
+          expect(representation).to eq(id: nil, name: nil, user: { name: nil, email: nil })
+        end
+
+        it 'can specify children attributes with mixed only and except' do
+          user_entity = Class.new(Grape::Entity)
+          user_entity.expose(:id, :name, :email, :address)
+
+          subject.expose(:id, :name, :phone, :mobile_phone)
+          subject.expose(:user, using: user_entity)
+
+          representation = subject.represent(OpenStruct.new(user: {}),
+                                             only: [:id, :name, :phone, user: [:id, :name, :email]],
+                                             except: [:phone, { user: [:id] }], serializable: true)
+          expect(representation).to eq(id: nil, name: nil, user: { name: nil, email: nil })
+        end
+
         context 'specify attribute with exposure condition' do
           it 'returns only specified fields' do
-            subject.expose(:id, :name)
+            subject.expose(:id)
             subject.with_options(if: { condition: true }) do
               subject.expose(:name)
             end
 
             representation = subject.represent(OpenStruct.new, condition: true, only: [:id, :name], serializable: true)
             expect(representation).to eq(id: nil, name: nil)
           end
+
+          it 'does not return fields specified in the except option' do
+            subject.expose(:id, :phone)
+            subject.with_options(if: { condition: true }) do
+              subject.expose(:name, :mobile_phone)
+            end
+
+            representation = subject.represent(OpenStruct.new, condition: true, except: [:phone, :mobile_phone], serializable: true)
+            expect(representation).to eq(id: nil, name: nil)
+          end
         end
 
         context 'attribute with alias' do
@@ -534,17 +582,31 @@ class Parent < Person
             representation = subject.represent(OpenStruct.new, condition: true, only: [:id, :title], serializable: true)
             expect(representation).to eq(id: nil, title: nil)
           end
+
+          it 'does not return fields specified in the except option' do
+            subject.expose(:id)
+            subject.expose(:name, as: :title)
+            subject.expose(:phone, as: :phone_number)
+
+            representation = subject.represent(OpenStruct.new, condition: true, except: [:phone_number], serializable: true)
+            expect(representation).to eq(id: nil, title: nil)
+          end
         end
 
         context 'attribute that is an entity itself' do
           it 'returns correctly the children entity attributes' do
             user_entity = Class.new(Grape::Entity)
             user_entity.expose(:id, :name, :email)
 
+            nephew_entity = Class.new(Grape::Entity)
+            nephew_entity.expose(:id, :name, :email)
+
             subject.expose(:id, :name, :phone)
             subject.expose(:user, using: user_entity)
+            subject.expose(:nephew, using: nephew_entity)
 
-            representation = subject.represent(OpenStruct.new(user: {}), only: [:id, :name, :user], serializable: true)
+            representation = subject.represent(OpenStruct.new(user: {}),
+                                               only: [:id, :name, :user], except: [:nephew], serializable: true)
             expect(representation).to eq(id: nil, name: nil, user: { id: nil, name: nil, email: nil })
           end
         end