Refactoring for cleaner middleware integration, added beforeAll hook

lib/index.js

@@ -77,6 +77,10 @@ module.exports = function initServeSpa(app, root, options) {
         throw new TypeError('The require option must be if type function.');
     }
 
+    if (!_.isUndefined(options.beforeAll) && !_.isFunction(options.beforeAll)) {
+        throw new TypeError('The beforeAll option must be if type function.');
+    }
+
 
     // Cache HTML templates
 
@@ -120,46 +124,14 @@ module.exports = function initServeSpa(app, root, options) {
     });
 
 
-    // Create and apply the middleware
-
-    function serveSpa(req, res, next) {
-
-        function render() {
-
-            if ((arguments.length === 1 && !_.isUndefined(arguments[0]) && !_.isNull(arguments[0])) || arguments.length > 1) {
-                // Error provided or route forward intended...
-                return next.apply(undefined, arguments);
-            }
-
-            var data = {
-                require: options.require || require,
-                request: req,
-                req: req,
-                response: res,
-                res: res
-            };
-
-            try {
-
-                var html = cache[cacheEntry].template(data);
-
-                res.set({
-                    'Cache-Control': 'no-cache, no-store, must-revalidate',
-                    'Pragma': 'no-cache',
-                    'Expires': '0'
-                });
-                res.send(html);
-
-            } catch(err) {
-                next(err);
-            }
+    // Create and apply the middlewares
 
-        }
+    function prepare(req, res, next) {
 
-        var url = parseurl(req);
+        parseurl(req);
 
         // Don't serve index.htmlt and compose.js directly
-        if (url.pathname.match(/\/(index.htmlt|compose.js)$/i) !== null) {
+        if (req._parsedUrl.pathname.match(/\/(index.htmlt|compose.js)$/i) !== null) {
             // Ignore files with same behavior as SendStream.prototype.error(404) in npm package 'send'
             var msg = statuses[404];
             res._headers = null;
@@ -171,26 +143,96 @@ module.exports = function initServeSpa(app, root, options) {
             return;
         }
 
+        // Configuration for downstream middlewares
+        req._serveSpa = {
+            before: false,
+            compose: false,
+            render: false
+        };
+
         // Serve static files as usual
-        if (!_.isUndefined(staticFiles[url.pathname])) {
+        if (!_.isUndefined(staticFiles[req._parsedUrl.pathname])) {
             return next();
         }
 
-        var cacheEntry = findCacheEntry(cache, url.pathname);
+        // Configuration for before middleware
+        if (!_.isUndefined(options.beforeAll)) {
+            req._serveSpa.before = options.beforeAll;
+        }
+
+        var cacheEntry = findCacheEntry(cache, req._parsedUrl.pathname);
         if (_.isUndefined(cacheEntry)) {
-            return next();
+            return next(); // serve-static will send a 404.
         }
 
-        // Render template
+        // Configuration for compose middleware
         if (!_.isUndefined(cache[cacheEntry].compose)) {
-            cache[cacheEntry].compose(req, res, render);
-        } else {
-            render();
+            req._serveSpa.compose = cache[cacheEntry].compose;
+        }
+
+        // Configuration for render middleware
+        req._serveSpa.render = cache[cacheEntry].template;
+
+        next();
+
+    }
+
+    function before(req, res, next) {
+
+        if (req._serveSpa.before === false) {
+            return next();
+        }
+
+        return req._serveSpa.before(req, res, next);
+
+    }
+
+    function compose(req, res, next) {
+
+        if (req._serveSpa.compose === false) {
+            return next();
+        }
+
+        return req._serveSpa.compose(req, res, next);
+
+    }
+
+    function render(req, res, next) {
+
+        if (req._serveSpa.render === false) {
+            return next();
+        }
+
+        var data = {
+            require: options.require || require,
+            request: req,
+            req: req,
+            response: res,
+            res: res
+        };
+
+        try {
+
+            var html = req._serveSpa.render(data);
+
+            res.set({
+                'Cache-Control': 'no-cache, no-store, must-revalidate',
+                'Pragma': 'no-cache',
+                'Expires': '0'
+            });
+            res.send(html);
+
+        } catch(err) {
+            next(err);
         }
 
     }
 
-    app.use(serveSpa);
+    app.use(prepare);
+    app.use(before);
+    app.use(compose);
+    app.use(render);
+
     app.use(serveStatic(root, options.staticSettings));