From a57b86257ce4ac4de3575d4d068d8b7f41eb40d4 Mon Sep 17 00:00:00 2001
From: Timothy J Warren <tim@timshomepage.net>
Date: Fri, 19 Feb 2016 16:23:00 -0500
Subject: [PATCH] Add content-negotiation

---
 app/Container.js             |  1 +
 app/config/error-handlers.js | 31 ++++++++++++++++++++++---------
 app/controllers/index.js     |  8 ++++++--
 app/views/error.stache       |  3 +++
 package.json                 |  1 +
 5 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/app/Container.js b/app/Container.js
index f1bd158..637d65c 100644
--- a/app/Container.js
+++ b/app/Container.js
@@ -2,6 +2,7 @@
 
 const errors = require('errors');
 const express = require('express');
+const negotiate = require('express-negotiate');
 const path = require('path');
 const autoLoad = require('./config/container-autoload');
 
diff --git a/app/config/error-handlers.js b/app/config/error-handlers.js
index 162dd65..0cdaa0a 100644
--- a/app/config/error-handlers.js
+++ b/app/config/error-handlers.js
@@ -8,15 +8,21 @@ const container = require('../Container');
 const app = container.get('app');
 const HTTP_CODE_MAP = require('http').STATUS_CODES;
 const errors = require('errors');
+const negotiate = require('express-negotiate');
 
 let errorHandlers = new Set([
 
-	function handle404(req, res, next) {
-		// if no route matches, send a 404
+	function handle400Errors(err, req, res, next) {
+
 		if (! req.route) {
-			let err = new errors.Http404Error();
-			return next(err);
+			// if no route matches, send a 404
+			err = new errors.Http404Error();
+		} else if (err instanceof negotiate.NotAcceptable) {
+			// if no content type matches, send a 406
+			err = new errors.Http406Error();
 		}
+
+		return next(err);
 	},
 
 	// general error handler
@@ -36,12 +42,19 @@ let errorHandlers = new Set([
 			output.error = err;
 		}
 
-		res.render('error', {
-			title: `${err.status} ${err.message}`,
-			error: output,
-		});
+		// Send html or json depending on client accept header
+		req.negotiate({
+			html: () => {
+				res.render('error', {
+					title: `${err.status} ${err.message}`,
+					error: output,
+				});
+			},
 
-		//res.json(output);
+			'application/json': () => {
+				res.json(output);
+			},
+		});
 	},
 ]);
 
diff --git a/app/controllers/index.js b/app/controllers/index.js
index dfa570f..a87d753 100644
--- a/app/controllers/index.js
+++ b/app/controllers/index.js
@@ -4,8 +4,12 @@ module.exports = {
 	'/': {
 		// Get homepage
 		get: (req, res) => {
-			return res.render('index', {
-				title: 'Blog test page',
+			req.negotiate({
+				html: () => {
+					return res.render('index', {
+						title: 'Blog test page',
+					});
+				},
 			});
 		},
 	},
diff --git a/app/views/error.stache b/app/views/error.stache
index b075502..af101d2 100644
--- a/app/views/error.stache
+++ b/app/views/error.stache
@@ -3,14 +3,17 @@
 	<h2>{{error.message}}</h2>
 	{{#if error.error}}
 	<article>
+		<center>
 		<table>
 			<caption>Error Details</caption>
 			{{#each error as |value key|}}
 			<tr>
 				<td>{{key}}</td>
 				<td>{{value}}</td>
+			</tr>
 			{{/each}}
 		</table>
+		</center>
 	</article>
 	{{/if}}
 </main>
\ No newline at end of file
diff --git a/package.json b/package.json
index 12acccd..52de28b 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
     "eslint": "^1.10.3",
     "express": "4.*",
     "express-handlebars": "^3.0.0",
+    "express-negotiate": "0.0.5",
     "express-session": "^1.13.0",
     "getargs": "0.0.8",
     "glob": "^6.0.4",