From 7fe4133b4af158daf51d1eddf5ba91b621a44847 Mon Sep 17 00:00:00 2001
From: Jonathan Ong <jonathanrichardong@gmail.com>
Date: Fri, 27 Dec 2013 13:56:21 -0800
Subject: [PATCH] refactor: move content negotiation to accepts

---
 lib/application.js |  2 ++
 lib/request.js     | 47 +++++++---------------------------------------
 package.json       |  2 +-
 3 files changed, 10 insertions(+), 41 deletions(-)

diff --git a/lib/application.js b/lib/application.js
index 89e575c..98fb103 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -11,6 +11,7 @@ var request = require('./request');
 var response = require('./response');
 var Cookies = require('cookies');
 var Keygrip = require('keygrip');
+var accepts = require('accepts');
 var assert = require('assert');
 var http = require('http');
 var co = require('co');
@@ -157,6 +158,7 @@ app.createContext = function(req, res){
   context.onerror = context.onerror.bind(context);
   context.originalUrl = request.originalUrl = req.url;
   context.cookies = new Cookies(req, res, this.keys);
+  context.accept = request.accept = accepts(req);
   return context;
 };
 
diff --git a/lib/request.js b/lib/request.js
index f445ede..87b87dc 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -4,7 +4,6 @@
  */
 
 var debug = require('debug')('koa:context');
-var Negotiator = require('negotiator');
 var qs = require('querystring');
 var fresh = require('fresh');
 var mime = require('mime');
@@ -394,16 +393,8 @@ module.exports = {
    * @api public
    */
 
-  accepts: function(types){
-    if (!Array.isArray(types)) types = [].slice.call(arguments);
-    var n = new Negotiator(this.req);
-    if (!types.length) return n.preferredMediaTypes();
-    if (!this.header.accept) return types[0];
-    var mimes = types.map(extToMime);
-    var accepts = n.preferredMediaTypes(mimes);
-    var first = accepts[0];
-    if (!first) return false;
-    return types[mimes.indexOf(first)];
+  accepts: function(){
+    return this.accept.types.apply(this.accept, arguments);
   },
 
   /**
@@ -419,11 +410,8 @@ module.exports = {
    * @api public
    */
 
-  acceptsEncodings: function(encodings) {
-    if (!Array.isArray(encodings)) encodings = [].slice.call(arguments);
-    var n = new Negotiator(this.req);
-    if (!encodings.length) return n.preferredEncodings();
-    return n.preferredEncodings(encodings)[0] || 'identity';
+  acceptsEncodings: function(){
+    return this.accept.encodings.apply(this.accept, arguments);
   },
 
   /**
@@ -439,12 +427,8 @@ module.exports = {
    * @api public
    */
 
-  acceptsCharsets: function(charsets) {
-    if (!Array.isArray(charsets)) charsets = [].slice.call(arguments);
-    var n = new Negotiator(this.req);
-    if (!charsets.length) return n.preferredCharsets();
-    if (!this.header['accept-charset']) return charsets[0];
-    return n.preferredCharsets(charsets)[0] || false;
+  acceptsCharsets: function(){
+    return this.accept.charsets.apply(this.accept, arguments);
   },
 
   /**
@@ -461,11 +445,7 @@ module.exports = {
    */
 
   acceptsLanguages: function(langs) {
-    if (!Array.isArray(langs)) langs = [].slice.call(arguments);
-    var n = new Negotiator(this.req);
-    if (!langs.length) return n.preferredLanguages();
-    if (!this.header['accept-language']) return langs[0];
-    return n.preferredLanguages(langs)[0] || false;
+    return this.accept.languages.apply(this.accept, arguments);
   },
 
   /**
@@ -614,19 +594,6 @@ module.exports = {
   }
 };
 
-/**
- * Convert extnames to mime.
- *
- * @param {String} type
- * @return {String}
- * @api private
- */
-
-function extToMime(type) {
-  if (~type.indexOf('/')) return type;
-  return mime.lookup(type);
-}
-
 /**
  * Check if `exected` mime type
  * matches `actual` mime type with
diff --git a/package.json b/package.json
index c87ca5e..178ee12 100644
--- a/package.json
+++ b/package.json
@@ -21,12 +21,12 @@
   ],
   "license": "MIT",
   "dependencies": {
+    "accepts": "~1.0.0",
     "on-socket-error": "~1.0.1",
     "co": "~3.0.1",
     "debug": "*",
     "mime": "~1.2.11",
     "fresh": "~0.2.0",
-    "negotiator": "~0.3.0",
     "koa-compose": "~2.1.0",
     "cookies": "~0.3.7",
     "keygrip": "~1.0.0"