Add XSL for Sitemaps

fixes TryGhost#4555

- There's no easy way to declare an XSL with the node xml module, so I
  needed to move the declarations to both be strings
- Ideally the code to serve the XSL would also be inside the sitemap
  module, but I think we need to refactor a bit to get there easily
- Added the XSL from TryGhost#4559, with minor amends to make the tables and urls
  display correctly

core/server/config/url.js

@@ -148,6 +148,9 @@ function urlFor(context, data, absolute) {
             }
 
             return urlPath;
+        } else if (context === 'sitemap-xsl') {
+            absolute = true;
+            urlPath = '/sitemap.xsl';
         }
         // other objects are recognised but not yet supported
     } else if (_.isString(context) && _.indexOf(_.keys(knownPaths), context) !== -1) {

core/server/data/sitemap/base-generator.js

@@ -1,9 +1,9 @@
-
-var _ = require('lodash'),
-    xml = require('xml'),
-    moment = require('moment'),
-    api = require('../../api'),
-    config = require('../../config'),
+var _       = require('lodash'),
+    xml     = require('xml'),
+    moment  = require('moment'),
+    api     = require('../../api'),
+    config  = require('../../config'),
+    utils   = require('./utils'),
     Promise = require('bluebird'),
     CHANGE_FREQ = 'weekly',
     XMLNS_DECLS;
@@ -87,9 +87,7 @@ _.extend(BaseSiteMapGenerator.prototype, {
         };
 
         // Return the xml
-        return xml(data, {
-            declaration: true
-        });
+        return utils.getDeclarations() + xml(data);
     },
 
     updateXmlFromNodes: function (urlElements) {

core/server/data/sitemap/handler.js

@@ -1,13 +1,13 @@
-var _ = require('lodash'),
-    utils = require('../utils'),
+var _       = require('lodash'),
+    utils   = require('../../utils'),
     sitemap = require('./index');
 
 // Responsible for handling requests for sitemap files
 module.exports = function (blogApp) {
     var resourceTypes = ['posts', 'authors', 'tags', 'pages'],
         verifyResourceType = function (req, res, next) {
             if (!_.contains(resourceTypes, req.param('resource'))) {
-                return res.send(404);
+                return res.sendStatus(404);
             }
 
             next();
@@ -19,7 +19,7 @@ module.exports = function (blogApp) {
     // Redirect normal sitemap.xml requests to sitemap-index.xml
     blogApp.get('/sitemap.xml', function (req, res) {
         res.set({'Cache-Control': 'public, max-age=' + utils.ONE_YEAR_S});
-        res.redirect(301, '/sitemap-index.xml');
+        res.redirect(301, req.baseUrl + '/sitemap-index.xml');
     });
 
     blogApp.get('/sitemap-index.xml', function (req, res) {

core/server/data/sitemap/index-generator.js

@@ -1,7 +1,8 @@
-var _ = require('lodash'),
-    xml = require('xml'),
-    moment = require('moment'),
-    config = require('../../config'),
+var _       = require('lodash'),
+    xml     = require('xml'),
+    moment  = require('moment'),
+    config  = require('../../config'),
+    utils   = require('./utils'),
     RESOURCES,
     XMLNS_DECLS;
 
@@ -27,9 +28,7 @@ _.extend(SiteMapIndexGenerator.prototype, {
             };
 
         // Return the xml
-        return xml(data, {
-            declaration: true
-        });
+        return utils.getDeclarations() + xml(data);
     },
 
     generateSiteMapUrlElements: function () {

core/server/data/sitemap/utils.js

@@ -0,0 +1,13 @@
+var config = require('../../config'),
+    utils;
+
+utils = {
+    getDeclarations: function () {
+        var baseUrl = config.urlFor('sitemap-xsl');
+        baseUrl = baseUrl.replace(/^(http:|https:)/, '');
+        return '<?xml version="1.0" encoding="UTF-8"?>' +
+            '<?xml-stylesheet type="text/xsl" href="' + baseUrl + 'sitemap.xsl"?>';
+    }
+};
+
+module.exports = utils;

core/server/middleware/index.js

@@ -264,6 +264,7 @@ setupMiddleware = function (blogAppInstance, adminApp) {
 
     // Favicon
     blogApp.use(serveSharedFile('favicon.ico', 'image/x-icon', utils.ONE_DAY_S));
+    blogApp.use(serveSharedFile('sitemap.xsl', 'text/xsl', utils.ONE_DAY_S));
 
     // Static assets
     blogApp.use('/shared', express['static'](path.join(corePath, '/shared'), {maxAge: utils.ONE_HOUR_MS}));