ArraySerializer is also cached

lib/active_model/array_serializer.rb

@@ -19,26 +19,18 @@ module ActiveModel
 
     class_attribute :root
 
-    def initialize(object, options={})
-      @object, @options = object, options
+    class_attribute :cache
+    class_attribute :perform_caching
+
+    class << self
+      # set peform caching like root
+      def cached(value = true)
+        self.perform_caching = value
+      end
     end
 
-    def serializable_array
-      @object.map do |item|
-        if @options.has_key? :each_serializer
-          serializer = @options[:each_serializer]
-        elsif item.respond_to?(:active_model_serializer)
-          serializer = item.active_model_serializer
-        end
-
-        serializable = serializer ? serializer.new(item, @options) : DefaultSerializer.new(item)
-
-        if serializable.respond_to?(:serializable_hash)
-          serializable.serializable_hash
-        else
-          serializable.as_json
-        end
-      end
+    def initialize(object, options={})
+      @object, @options = object, options
     end
 
     def meta_key
@@ -61,6 +53,52 @@ module ActiveModel
         serializable_array
       end
     end
-  end
 
+    def to_json(*args)
+      if perform_caching?
+        cache.fetch expand_cache_key([self.class.to_s.underscore, cache_key, 'to-json']) do
+          super
+        end
+      else
+        super
+      end
+    end
+
+    def serializable_array
+      if perform_caching?
+        cache.fetch expand_cache_key([self.class.to_s.underscore, cache_key, 'serializable-array']) do
+          _serializable_array
+        end
+      else
+        _serializable_array
+      end
+    end
+
+    private
+    def _serializable_array
+      @object.map do |item|
+        if @options.has_key? :each_serializer
+          serializer = @options[:each_serializer]
+        elsif item.respond_to?(:active_model_serializer)
+          serializer = item.active_model_serializer
+        end
+
+        serializable = serializer ? serializer.new(item, @options) : DefaultSerializer.new(item)
+
+        if serializable.respond_to?(:serializable_hash)
+          serializable.serializable_hash
+        else
+          serializable.as_json
+        end
+      end
+    end
+
+    def expand_cache_key(*args)
+      ActiveSupport::Cache.expand_cache_key(args)
+    end
+
+    def perform_caching?
+      perform_caching && cache && respond_to?(:cache_key)
+    end
+  end
 end

lib/active_model_serializers.rb

@@ -26,7 +26,10 @@ if defined?(Rails)
 
       initializer "caching.active_model_serializer" do |app|
         ActiveModel::Serializer.perform_caching = app.config.action_controller.perform_caching
+        ActiveModel::ArraySerializer.perform_caching = app.config.action_controller.perform_caching
+
         ActiveModel::Serializer.cache = Rails.cache
+        ActiveModel::ArraySerializer.cache = Rails.cache
       end
     end
   end

test/caching_test.rb

@@ -121,4 +121,26 @@ class CachingTest < ActiveModel::TestCase
     assert serializer.cache.read('serializer/custom-key/to-json')
     assert serializer.cache.read('serializer/custom-key/serializable-hash')
   end
+
+  def test_array_serializer_uses_cache
+    serializer = Class.new(ActiveModel::ArraySerializer) do
+      cached true
+
+      def self.to_s
+        'array_serializer'
+      end
+
+      def cache_key
+        'cache-key'
+      end
+    end
+
+    serializer.cache = NullStore.new
+    instance = serializer.new [Programmer.new]
+
+    instance.to_json
+
+    assert serializer.cache.read('array_serializer/cache-key/serializable-array')
+    assert serializer.cache.read('array_serializer/cache-key/to-json')
+  end
 end