Added function negotiateContentType(); Fixed conneg; Fixed quotes for rel values

Author: deiu

lib/header.js

@@ -2,17 +2,18 @@ var li = require('li');
 
 var path = require('path');
 var S = require('string');
+var Negotiator = require('negotiator');
 var metadata = require('./metadata.js');
 var utils = require('./utils.js');
 var ldpVocab = require('./vocab/ldp.js');
 
 function addLink(res, value, rel) {
     var oldLink = res.get('Link');
     if (oldLink === undefined)
-        res.set('Link', '<' + value + '>; rel=\'' + rel + '\'');
+        res.set('Link', '<' + value + '>; rel="' + rel + '"');
     else
         res.set('Link', oldLink + ', ' + '<' + value +
-            '>; rel=\'' + rel + '\'');
+            '>; rel="' + rel + '"');
 }
 
 function addLinks(res, fileMetadata) {
@@ -74,25 +75,38 @@ function parseMetadataFromHeader(linkHeader) {
     return fileMetadata;
 }
 
-function parseAcceptHeader(req) {
+
+// Returns an array containing mime types from Accept header, ordered by priority
+// If no Accept value, serve turtle by default
+function negotiateContentType(req) {
+    var negotiator = new Negotiator(req);
+    return negotiator.mediaTypes();
+}
+
+function parseAcceptRDFHeader(req) {
     var acceptFinalValue;
-    var acceptHeader = req.get('Accept');
-    if (acceptHeader === undefined) {
+    var acceptHeader = negotiateContentType(req);
+    if (acceptHeader === undefined || acceptHeader.length === 0) {
         acceptFinalValue = undefined;
     } else {
-        switch (acceptHeader) {
-            case 'text/turtle':
-            case 'applicatoin/x-turtle':
-            case 'text/n3':
-            case 'application/rdf+xml':
-            case 'application/n3':
-            case 'application/json+ld':
-            case 'application/nquads':
-            case 'application/n-quads':
-                acceptFinalValue = acceptHeader;
+        for (var i in acceptHeader) {
+            switch (acceptHeader[i]) {
+                case 'text/turtle':
+                case 'application/x-turtle':
+                case 'text/n3':
+                case 'application/rdf+xml':
+                case 'application/n3':
+                case 'application/ld+json':
+                case 'application/nquads':
+                case 'application/n-quads':
+                    acceptFinalValue = acceptHeader[i];
+                    break;
+                default:
+                    acceptFinalValue = undefined;
+            }
+            if (acceptFinalValue !== undefined) {
                 break;
-            default:
-                acceptFinalValue = undefined;
+            }
         }
     }
     return acceptFinalValue;
@@ -101,5 +115,6 @@ function parseAcceptHeader(req) {
 module.exports.addLink = addLink;
 module.exports.addLinks = addLinks;
 module.exports.parseMetadataFromHeader = parseMetadataFromHeader;
-module.exports.parseAcceptHeader = parseAcceptHeader;
+module.exports.parseAcceptRDFHeader = parseAcceptRDFHeader;
 module.exports.linksHandler = linksHandler;
+module.exports.negotiateContentType = negotiateContentType;