Provide Rails url_helpers via SerializationContext

lib/active_model/serializer/links.rb

@@ -20,9 +20,11 @@ module ActiveModel
 
         # Define a link on a serializer.
         # @example
-        #   link :self { "//example.com/posts/#{object.id}" }
+        #   link(:self) { resource_url(object) }
         # @example
-        #   link :self, "//example.com/user"
+        #   link(:self) { "http://example.com/resource/#{object.id}" }
+        # @example
+        #   link :resource, "http://example.com/resource"
         #
         def link(name, value = nil, &block)
           _links[name] = block || value

lib/active_model_serializers/adapter/json_api/link.rb

@@ -1,7 +1,12 @@
+require 'active_support/core_ext/module/delegation'
+
 module ActiveModelSerializers
   module Adapter
     class JsonApi
       class Link
+        include SerializationContext.url_helpers
+        delegate :default_url_options, to: SerializationContext
+
         def initialize(serializer, value)
           @object = serializer.object
           @scope = serializer.scope

lib/active_model_serializers/railtie.rb

@@ -15,6 +15,11 @@ module ActiveModelSerializers
       end
     end
 
+    initializer 'active_model_serializers.prepare_serialization_context' do
+      SerializationContext.url_helpers = Rails.application.routes.url_helpers
+      SerializationContext.default_url_options = Rails.application.routes.default_url_options
+    end
+
     # This hook is run after the action_controller railtie has set the configuration
     # based on the *environment* configuration and before any config/initializers are run
     # and also before eager_loading (if enabled).

lib/active_model_serializers/serialization_context.rb

@@ -1,10 +1,24 @@
 module ActiveModelSerializers
   class SerializationContext
+    class << self
+      attr_writer :url_helpers, :default_url_options
+    end
+
     attr_reader :request_url, :query_parameters
 
-    def initialize(request)
+    def initialize(request, options = {})
       @request_url = request.original_url[/\A[^?]+/]
       @query_parameters = request.query_parameters
+      @url_helpers = options.delete(:url_helpers) || self.class.url_helpers
+      @default_url_options = options.delete(:default_url_options) || self.class.default_url_options
+    end
+
+    def self.url_helpers
+      @url_helpers ||= Module.new
+    end
+
+    def self.default_url_options
+      @default_url_options ||= {}
     end
   end
 end