Add configuration/hook for cache.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### Added
 
+* Default configuration and hooks for the `cache` parameter.
 * Default configuration and hooks for the `links` parameter.
 * Default configuration and hooks for the `fields` parameter.
 * Default configuration and hooks for the `include` parameter.

lib/generators/jsonapi/initializer/templates/initializer.rb

@@ -21,6 +21,16 @@
   #   version: '1.0'
   # }
   #
+  # # Set default cache.
+  # # A lambda/proc that will be eval'd in the controller context.
+  # config.jsonapi_cache = ->() { nil }
+  #
+  # # Uncomment the following to enable fragment caching. Make sure you
+  # #   invalidate cache keys accordingly.
+  # config.jsonapi_cache = lambda {
+  #   Rails.cache
+  # }
+  #
   # # Set default exposures.
   # # A lambda/proc that will be eval'd in the controller context.
   # config.jsonapi_expose = lambda {

lib/jsonapi/rails/configuration.rb

@@ -23,6 +23,8 @@ module Configurable
         version: '1.0'
       }.freeze
 
+      DEFAULT_JSONAPI_CACHE = ->() { nil }
+
       DEFAULT_JSONAPI_EXPOSE = lambda {
         { url_helpers: ::Rails.application.routes.url_helpers }
       }
@@ -38,6 +40,7 @@ module Configurable
       DEFAULT_CONFIG = {
         jsonapi_class: DEFAULT_JSONAPI_CLASS,
         jsonapi_errors_class: DEFAULT_JSONAPI_ERRORS_CLASS,
+        jsonapi_cache:   DEFAULT_JSONAPI_CACHE,
         jsonapi_expose:  DEFAULT_JSONAPI_EXPOSE,
         jsonapi_fields:  DEFAULT_JSONAPI_FIELDS,
         jsonapi_include: DEFAULT_JSONAPI_INCLUDE,

lib/jsonapi/rails/controller.rb

@@ -110,6 +110,12 @@ def jsonapi_expose
         instance_exec(&JSONAPI::Rails.config[:jsonapi_expose])
       end
 
+      # Hook for default cache.
+      # @return [#fetch_multi]
+      def jsonapi_cache
+        instance_exec(&JSONAPI::Rails.config[:jsonapi_cache])
+      end
+
       # Hook for default fields.
       # @return [Hash{Symbol=>Array<Symbol>}]
       def jsonapi_fields

lib/jsonapi/rails/renderer.rb

@@ -22,6 +22,7 @@ def render(resources, options, controller)
       def default_options(options, controller, resources)
         options.dup.tap do |opts|
           opts[:class] ||= controller.jsonapi_class
+          opts[:cache] ||= controller.jsonapi_cache
           opts[:links] =
             controller.jsonapi_links
                       .merge!(controller.jsonapi_pagination(resources))