Prefer object.cache_key when available.

lib/active_model/serializer/caching.rb

@@ -58,10 +58,6 @@ module ActiveModel
           ''.freeze
         end
 
-        def _skip_digest?
-          _cache_options && _cache_options[:skip_digest]
-        end
-
         # @api private
         # Used by FragmentCache on the CachedSerializer
         #  to call attribute methods on the fragmented cached serializer.
@@ -146,18 +142,6 @@ module ActiveModel
             (_cache_only && !_cache_except || !_cache_only && _cache_except)
         end
       end
-
-      # Use object's cache_key if available, else derive a key from the object
-      # Pass the `key` option to the `cache` declaration or override this method to customize the cache key
-      def cache_key
-        if object.respond_to?(:cache_key)
-          object.cache_key
-        else
-          object_time_safe = object.updated_at
-          object_time_safe = object_time_safe.strftime('%Y%m%d%H%M%S%9N') if object_time_safe.respond_to?(:strftime)
-          "#{self.class._cache_key}/#{object.id}-#{object_time_safe}"
-        end
-      end
     end
   end
 end

lib/active_model_serializers/adapter/base.rb

@@ -8,10 +8,6 @@ module ActiveModelSerializers
         ActiveModelSerializers::Adapter.register(subclass)
       end
 
-      def self.name
-        to_s.demodulize
-      end
-
       attr_reader :serializer, :instance_options
 
       def initialize(serializer, options = {})
@@ -19,10 +15,6 @@ module ActiveModelSerializers
         @instance_options = options
       end
 
-      def name
-        self.class.name
-      end
-
       def serializable_hash(_options = nil)
         fail NotImplementedError, 'This is an abstract method. Should be implemented at the concrete adapter.'
       end

lib/active_model_serializers/cached_serializer.rb

@@ -4,13 +4,12 @@ module ActiveModelSerializers
 
     def initialize(serializer)
       @cached_serializer = serializer
-      return unless cached? && !@cached_serializer.object.respond_to?(:cache_key) && @klass._cache_key.blank?
-      fail(UndefinedCacheKey, "#{@cached_serializer.object} must define #cache_key, or the cache_key option must be passed into cache on #{@cached_serializer}")
+      @klass             = @cached_serializer.class
     end
 
     def cache_check(adapter_instance)
       if cached?
-        @klass._cache.fetch(cache_key(adapter_instance), @klass._cache_options) do
+        @klass._cache.fetch(cache_key, @klass._cache_options) do
           yield
         end
       elsif fragment_cached?
@@ -28,16 +27,29 @@ module ActiveModelSerializers
       @klass.fragment_cache_enabled?
     end
 
-    def cache_key(adapter_instance)
+    def cache_key
       return @cache_key if defined?(@cache_key)
 
       parts = []
-      parts << @cached_serializer.cache_key
-      parts << adapter_instance.name.underscore
-      parts << @klass._cache_digest unless @klass._skip_digest?
+      parts << object_cache_key
+      parts << @klass._cache_digest unless @klass._cache_options && @klass._cache_options[:skip_digest]
       @cache_key = parts.join('/')
     end
 
+    # Use object's cache_key if available, else derive a key from the object
+    # Pass the `key` option to the `cache` declaration or override this method to customize the cache key
+    def object_cache_key
+      if @cached_serializer.object.respond_to?(:cache_key)
+        @cached_serializer.object.cache_key
+      elsif (cache_key = (@klass._cache_key || @klass._cache_options[: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)
+        "#{cache_key}/#{@cached_serializer.object.id}-#{object_time_safe}"
+      else
+        fail UndefinedCacheKey, "#{@cached_serializer.object.class} must define #cache_key, or the 'key:' option must be passed into '#{@klass}.cache'"
+      end
+    end
+
     # find all cache_key for the collection_serializer
     # @param collection_serializer
     # @param include_tree