Use protocol media for response negotiation.

Author: samuel-williams-shopify

lib/utopia/controller/responder.rb

@@ -5,25 +5,23 @@
 
 require_relative "middleware"
 
+require "protocol/http/header/accept"
+require "protocol/media/map"
+require "protocol/media/type"
+require "protocol/media/range"
+
 module Utopia
 	module Controller
 		# @namespace
 		module Handlers
 			# Serializes controller values as JSON responses.
 			module JSON
-				APPLICATION_JSON = HTTP::Accept::ContentType.new("application", "json").freeze
-				
-				# Delegate content-type splitting to the JSON media type.
-				# @parameter arguments [Array] The arguments.
-				# @returns [Array] The resulting values.
-				def self.split(*arguments)
-					APPLICATION_JSON.split(*arguments)
-				end
+				APPLICATION_JSON = Protocol::Media::Type.new("application", "json").freeze
 
 				# Serialize an object as a successful JSON response.
 				# @parameter context [Object] The context.
 				# @parameter request [Utopia::Request] The request.
-				# @parameter media_range [HTTP::Accept::MediaTypes::MediaRange] The negotiated media range.
+				# @parameter media_range [Protocol::HTTP::Header::Accept::MediaRange] The negotiated media range.
 				# @parameter object [Object] The object.
 				# @parameter options [Hash] The options.
 				# @returns [Object] The result of {Controller::Base#succeed!}.
@@ -38,19 +36,12 @@ def self.call(context, request, media_range, object, **options)
 
 			# Passes response values through without transformation.
 			module Passthrough
-				WILDCARD = HTTP::Accept::MediaTypes::MediaRange.new("*", "*").freeze
-				
-				# Delegate content-type splitting to the wildcard media range.
-				# @parameter arguments [Array] The arguments.
-				# @returns [Array] The resulting values.
-				def self.split(*arguments)
-					WILDCARD.split(*arguments)
-				end
+				WILDCARD = Protocol::Media::Range.new("*", "*").freeze
 
 				# Accept an object without producing a response.
 				# @parameter context [Object] The context.
 				# @parameter request [Utopia::Request] The request.
-				# @parameter media_range [HTTP::Accept::MediaTypes::MediaRange] The negotiated media range.
+				# @parameter media_range [Protocol::HTTP::Header::Accept::MediaRange] The negotiated media range.
 				# @parameter object [Object] The object.
 				# @parameter options [Hash] The options.
 				# @returns [Nil] No response is produced.
@@ -64,17 +55,10 @@ def self.call(context, request, media_range, object, **options)
 		class Responder
 			# A content-type handler and its response block.
 			Handler = Struct.new(:content_type, :block) do
-				# Delegate content-type splitting to this handler's content type.
-				# @parameter arguments [Array] The arguments.
-				# @returns [Array] The resulting values.
-				def split(*arguments)
-					self.content_type.split(*arguments)
-				end
-				
 				# Invoke this handler's block in the controller context.
 				# @parameter context [Object] The context.
 				# @parameter request [Utopia::Request] The request.
-				# @parameter media_range [HTTP::Accept::MediaTypes::MediaRange] The negotiated media range.
+				# @parameter media_range [Protocol::HTTP::Header::Accept::MediaRange] The negotiated media range.
 				# @parameter arguments [Array] The arguments.
 				# @parameter options [Hash] The options.
 				# @returns [Object] The handler block's result.
@@ -93,7 +77,7 @@ def with(object, **options)
 
 			# Initialize an empty content-type handler map.
 			def initialize
-				@handlers = HTTP::Accept::MediaTypes::Map.new
+				@handlers = Protocol::Media::Map.new
 			end
 
 			attr :handlers
@@ -113,10 +97,11 @@ def freeze
 			# @parameter options [Hash] The options.
 			# @returns [Object | Nil] The selected handler's result, or `nil` if none matches.
 			def call(context, request, *arguments, **options)
-				# Parse the list of browser preferred content types and return ordered by priority:
-				media_types = HTTP::Accept::MediaTypes.browser_preferred_media_types(
-					HTTP::Accept::MediaTypes::HTTP_ACCEPT => Array(request.headers["accept"]).join(",")
-				)
+				if accept = request.headers["accept"]
+					media_types = accept.media_ranges.sort
+				else
+					media_types = [Handlers::Passthrough::WILDCARD]
+				end
 
 				handler, media_range = @handlers.for(media_types)
 
@@ -127,7 +112,8 @@ def call(context, request, *arguments, **options)
 
 			# Add a converter for the specified content type. Call the block with the response content if the request accepts the specified content_type.
 			def handle(content_type, &block)
-				@handlers << Handler.new(content_type, block)
+				@handlers[content_type] = Handler.new(content_type, block)
+				return @handlers
 			end
 
 			# Bind this responder to a context and request.
@@ -139,21 +125,23 @@ def respond_to(context, request)
 			end
 
 			# Register the default JSON handler.
-			# @returns [HTTP::Accept::MediaTypes::Map] The updated handler map.
+			# @returns [Protocol::Media::Map] The updated handler map.
 			def with_json
-				@handlers << Handlers::JSON
+				@handlers[Handlers::JSON::APPLICATION_JSON] = Handlers::JSON
+				return @handlers
 			end
 
 			# Register the wildcard passthrough handler.
-			# @returns [HTTP::Accept::MediaTypes::Map] The updated handler map.
+			# @returns [Protocol::Media::Map] The updated handler map.
 			def with_passthrough
-				@handlers << Handlers::Passthrough
+				@handlers[Handlers::Passthrough::WILDCARD] = Handlers::Passthrough
+				return @handlers
 			end
 
 			# Invoke the responder with the given object.
 			# @parameter content_type [String] The content type.
 			# @yields The response handler body.
-			# @returns [HTTP::Accept::MediaTypes::Map] The updated handler map.
+			# @returns [Protocol::Media::Map] The updated handler map.
 			def with(content_type, &block)
 				handle(content_type, &block)
 			end

test/utopia/controller/respond.rb

@@ -73,6 +73,12 @@ def mock_request(path, headers = {})
 		expect(response.read).to be == '{"user_id":10}'
 	end
 
+	it "can register a passthrough handler" do
+		responder = Utopia::Controller::Responder.new
+		
+		expect(responder.with_passthrough).to be == responder.handlers
+		expect(responder.handlers["*/*"]).to be == Utopia::Controller::Handlers::Passthrough
+	end
 end
 
 describe Utopia::Controller do

utopia.gemspec

@@ -35,6 +35,7 @@ Gem::Specification.new do |spec|
 	spec.add_dependency "msgpack"
 	spec.add_dependency "net-smtp"
 	spec.add_dependency "protocol-http", "~> 0.58"
+	spec.add_dependency "protocol-media", "~> 0.1"
 	spec.add_dependency "protocol-url", "~> 0.4"
 	spec.add_dependency "samovar", "~> 2.1"
 	spec.add_dependency "traces", "~> 0.10"