Move CachedSerializer/FragmentCache to AMS namespace

Author: bf4

lib/active_model/serializer/adapter/base.rb

@@ -1,4 +1,3 @@
-require 'active_model/serializer/cached_serializer'
 module ActiveModel
   class Serializer
     module Adapter
@@ -30,7 +29,7 @@ def fragment_cache(cached_hash, non_cached_hash)
         end
 
         def cache_check(serializer)
-          ActiveModel::Serializer::CachedSerializer.new(serializer).cache_check(self) do
+          ActiveModelSerializers::CachedSerializer.new(serializer).cache_check(self) do
             yield
           end
         end

lib/active_model/serializer/cached_serializer.rb

@@ -4,6 +4,8 @@
 module ActiveModelSerializers
   extend ActiveSupport::Autoload
   autoload :Model
+  autoload :CachedSerializer
+  autoload :FragmentCache
   autoload :Callbacks
   autoload :Deserialization
   autoload :Logging

lib/active_model/serializer/fragment_cache.rb

@@ -0,0 +1,42 @@
+require 'active_model_serializers/fragment_cache'
+module ActiveModelSerializers
+  class CachedSerializer
+    def initialize(serializer)
+      @cached_serializer = serializer
+      @klass             = @cached_serializer.class
+    end
+
+    def cache_check(adapter_instance)
+      if cached?
+        @klass._cache.fetch(cache_key, @klass._cache_options) do
+          yield
+        end
+      elsif fragment_cached?
+        FragmentCache.new(adapter_instance, @cached_serializer, adapter_instance.instance_options).fetch
+      else
+        yield
+      end
+    end
+
+    def cached?
+      @klass._cache && !@klass._cache_only && !@klass._cache_except
+    end
+
+    def fragment_cached?
+      @klass._cache_only && !@klass._cache_except || !@klass._cache_only && @klass._cache_except
+    end
+
+    def cache_key
+      parts = []
+      parts << object_cache_key
+      parts << @klass._cache_digest unless @klass._cache_options && @klass._cache_options[:skip_digest]
+      parts.join('/')
+    end
+
+    def object_cache_key
+      object_time_safe = @cached_serializer.object.updated_at
+      object_time_safe = object_time_safe.strftime('%Y%m%d%H%M%S%9N') if object_time_safe.respond_to?(:strftime)
+      (@klass._cache_key) ? "#{@klass._cache_key}/#{@cached_serializer.object.id}-#{object_time_safe}" : @cached_serializer.object.cache_key
+    end
+  end
+end

lib/active_model_serializers.rb

@@ -0,0 +1,107 @@
+module ActiveModelSerializers
+  class FragmentCache
+    attr_reader :serializer
+
+    def initialize(adapter, serializer, options)
+      @instance_options = options
+      @adapter    = adapter
+      @serializer = serializer
+    end
+
+    # TODO: Use Serializable::Resource
+    # TODO: call +constantize+ less
+    # 1. Create a CachedSerializer and NonCachedSerializer from the serializer class
+    # 2. Serialize the above two with the given adapter
+    # 3. Pass their serializations to the adapter +::fragment_cache+
+    def fetch
+      klass = serializer.class
+      # It will split the serializer into two, one that will be cached and one that will not
+      serializers = fragment_serializer(serializer.object.class.name, klass)
+
+      # Instantiate both serializers
+      cached_serializer     = serializers[:cached].constantize.new(serializer.object)
+      non_cached_serializer = serializers[:non_cached].constantize.new(serializer.object)
+
+      cached_adapter     = adapter.class.new(cached_serializer, instance_options)
+      non_cached_adapter = adapter.class.new(non_cached_serializer, instance_options)
+
+      # Get serializable hash from both
+      cached_hash     = cached_adapter.serializable_hash
+      non_cached_hash = non_cached_adapter.serializable_hash
+
+      # Merge both results
+      adapter.fragment_cache(cached_hash, non_cached_hash)
+    end
+
+    protected
+
+    attr_reader :instance_options, :adapter
+
+    private
+
+    # Given a serializer class and a hash of its cached and non-cached serializers
+    # 1. Determine cached attributes from serializer class options
+    # 2. Add cached attributes to cached Serializer
+    # 3. Add non-cached attributes to non-cached Serializer
+    def cached_attributes(klass, serializers)
+      attributes            = serializer.class._attributes
+      cached_attributes     = (klass._cache_only) ? klass._cache_only : attributes.reject { |attr| klass._cache_except.include?(attr) }
+      non_cached_attributes = attributes - cached_attributes
+
+      cached_attributes.each do |attribute|
+        options = serializer.class._attributes_keys[attribute]
+        options ||= {}
+        # Add cached attributes to cached Serializer
+        serializers[:cached].constantize.attribute(attribute, options)
+      end
+
+      non_cached_attributes.each do |attribute|
+        options = serializer.class._attributes_keys[attribute]
+        options ||= {}
+        # Add non-cached attributes to non-cached Serializer
+        serializers[:non_cached].constantize.attribute(attribute, options)
+      end
+    end
+
+    # Given a resource name and its serializer's class
+    # 1. Dyanmically creates a CachedSerializer and NonCachedSerializer
+    #   for a given class 'name'
+    # 2. Call
+    #       CachedSerializer.cache(serializer._cache_options)
+    #       CachedSerializer.fragmented(serializer)
+    #       NonCachedSerializer.cache(serializer._cache_options)
+    # 3. Build a hash keyed to the +cached+ and +non_cached+ serializers
+    # 4. Call +cached_attributes+ on the serializer class and the above hash
+    # 5. Return the hash
+    #
+    # @example
+    #   When +name+ is <tt>User::Admin</tt>
+    #   creates the Serializer classes (if they don't exist).
+    #     User_AdminCachedSerializer
+    #     User_AdminNonCachedSerializer
+    #
+    def fragment_serializer(name, klass)
+      cached     = "#{to_valid_const_name(name)}CachedSerializer"
+      non_cached = "#{to_valid_const_name(name)}NonCachedSerializer"
+
+      Object.const_set cached, Class.new(ActiveModel::Serializer) unless Object.const_defined?(cached)
+      Object.const_set non_cached, Class.new(ActiveModel::Serializer) unless Object.const_defined?(non_cached)
+
+      klass._cache_options ||= {}
+      klass._cache_options[:key] = klass._cache_key if klass._cache_key
+
+      cached.constantize.cache(klass._cache_options)
+
+      cached.constantize.fragmented(serializer)
+      non_cached.constantize.fragmented(serializer)
+
+      serializers = { cached: cached, non_cached: non_cached }
+      cached_attributes(klass, serializers)
+      serializers
+    end
+
+    def to_valid_const_name(name)
+      name.gsub('::', '_')
+    end
+  end
+end

lib/active_model_serializers/cached_serializer.rb

@@ -1,35 +1,33 @@
 require 'test_helper'
-module ActiveModel
-  class Serializer
-    class FragmentCacheTest < ActiveSupport::TestCase
-      def setup
-        super
-        @spam            = Spam::UnrelatedLink.new(id: 'spam-id-1')
-        @author          = Author.new(name: 'Joao M. D. Moura')
-        @role            = Role.new(name: 'Great Author', description: nil)
-        @role.author     = [@author]
-        @role_serializer = RoleSerializer.new(@role)
-        @spam_serializer = Spam::UnrelatedLinkSerializer.new(@spam)
-        @role_hash       = FragmentCache.new(RoleSerializer.adapter.new(@role_serializer), @role_serializer, {})
-        @spam_hash       = FragmentCache.new(Spam::UnrelatedLinkSerializer.adapter.new(@spam_serializer), @spam_serializer, {})
-      end
+module ActiveModelSerializers
+  class FragmentCacheTest < ActiveSupport::TestCase
+    def setup
+      super
+      @spam            = Spam::UnrelatedLink.new(id: 'spam-id-1')
+      @author          = Author.new(name: 'Joao M. D. Moura')
+      @role            = Role.new(name: 'Great Author', description: nil)
+      @role.author     = [@author]
+      @role_serializer = RoleSerializer.new(@role)
+      @spam_serializer = Spam::UnrelatedLinkSerializer.new(@spam)
+      @role_hash       = FragmentCache.new(RoleSerializer.adapter.new(@role_serializer), @role_serializer, {})
+      @spam_hash       = FragmentCache.new(Spam::UnrelatedLinkSerializer.adapter.new(@spam_serializer), @spam_serializer, {})
+    end
 
-      def test_fragment_fetch_with_virtual_attributes
-        expected_result = {
-          id: @role.id,
-          description: @role.description,
-          slug: "#{@role.name}-#{@role.id}",
-          name: @role.name
-        }
-        assert_equal(@role_hash.fetch, expected_result)
-      end
+    def test_fragment_fetch_with_virtual_attributes
+      expected_result = {
+        id: @role.id,
+        description: @role.description,
+        slug: "#{@role.name}-#{@role.id}",
+        name: @role.name
+      }
+      assert_equal(@role_hash.fetch, expected_result)
+    end
 
-      def test_fragment_fetch_with_namespaced_object
-        expected_result = {
-          id: @spam.id
-        }
-        assert_equal(@spam_hash.fetch, expected_result)
-      end
+    def test_fragment_fetch_with_namespaced_object
+      expected_result = {
+        id: @spam.id
+      }
+      assert_equal(@spam_hash.fetch, expected_result)
     end
   end
 end