Add hook for default exposures.

lib/jsonapi/rails/action_controller.rb

@@ -42,6 +42,12 @@ def deserializable_resource(key, options = {}, &block)
         end
       end
 
+      def jsonapi_expose
+        {
+          url_helpers: ::Rails.application.routes.url_helpers
+        }
+      end
+
       def jsonapi_pagination(_collection)
         nil
       end

lib/jsonapi/rails/railtie.rb

@@ -30,18 +30,17 @@ class Railtie < ::Rails::Railtie
           ::ActionController::Renderers.add(:jsonapi) do |resources, options|
             self.content_type ||= Mime[:jsonapi]
 
-            # Renderer proc is evaluated in the controller context, so it
-            # has access to the jsonapi_pagination method.
+            # Renderer proc is evaluated in the controller context.
             if (pagination_links = jsonapi_pagination(resources))
               (options[:links] ||= {}).merge!(pagination_links)
             end
+            options[:expose] = jsonapi_expose.merge!(options[:expose] || {})
 
             RENDERERS[:jsonapi].render(resources, options).to_json
           end
 
           ::ActionController::Renderers.add(:jsonapi_error) do |errors, options|
-            # Renderer proc is evaluated in the controller context, so it
-            # has access to the jsonapi_pointers method.
+            # Renderer proc is evaluated in the controller context.
             options = options.merge(_jsonapi_pointers: jsonapi_pointers)
             self.content_type ||= Mime[:jsonapi]
 

lib/jsonapi/rails/renderer.rb

@@ -11,11 +11,6 @@ def initialize(renderer = JSONAPI::Serializable::SuccessRenderer.new)
 
       def render(resources, options)
         opts = options.dup
-        # TODO(beauby): Move this to a global configuration.
-        default_exposures = {
-          url_helpers: ::Rails.application.routes.url_helpers
-        }
-        opts[:expose] = default_exposures.merge!(opts[:expose] || {})
         opts[:jsonapi] = opts.delete(:jsonapi_object)
 
         @renderer.render(resources, opts)