updated error-pages example

examples/error-pages/app.js

@@ -9,13 +9,15 @@ require.paths.unshift(__dirname + '/../../support');
 var express = require('../../lib/express');
 
 var app = express.createServer();
+app.set('views', __dirname + '/views');
+app.set('view engine', 'jade');
 
 // Serve default connect favicon
 app.use(express.favicon());
 
 // Logger is placed below favicon, so favicon.ico
 // requests will not be logged
-app.use(express.logger({ format: '":method :url" :status' }));
+app.use(express.logger('":method :url" :status'));
 
 // "app.router" positions our routes 
 // specifically above the middleware
@@ -23,59 +25,38 @@ app.use(express.logger({ format: '":method :url" :status' }));
 
 app.use(app.router);
 
-// When no more middleware require execution, aka
-// our router is finished and did not respond, we
-// can assume that it is "not found". Instead of
-// letting Connect deal with this, we define our
-// custom middleware here to simply pass a NotFound
-// exception
+// Since this is the last non-error-handling
+// middleware use()d, we assume 404, as nothing else
+// responded.
 
 app.use(function(req, res, next){
-  next(new NotFound(req.url));
+  // the status option, or res.statusCode = 404
+  // are equivalent, however with the option we
+  // get the "status" local available as well
+  res.render('404', { status: 404, url: req.url });
 });
 
-app.set('views', __dirname + '/views');
+// error-handling middleware, take the same form
+// as regular middleware, however they require an
+// arity of 4, aka the signature (err, req, res, next).
+// when connect has an error, it will invoke ONLY error-handling
+// middleware.
 
-// Provide our app with the notion of NotFound exceptions
+// If we were to next() here any remaining non-error-handling
+// middleware would then be executed, or if we next(err) to
+// continue passing the error, only error-handling middleware
+// would remain being executed, however here
+// we simply respond with an error page.
 
-function NotFound(path){
-  this.name = 'NotFound';
-  if (path) {
-    Error.call(this, 'Cannot find ' + path);
-    this.path = path;
-  } else {
-    Error.call(this, 'Not Found');
-  }
-  Error.captureStackTrace(this, arguments.callee);
-}
 
-/**
- * Inherit from `Error.prototype`.
- */
-
-NotFound.prototype.__proto__ = Error.prototype;
-
-// We can call app.error() several times as shown below.
-// Here we check for an instanceof NotFound and show the
-// 404 page, or we pass on to the next error handler.
-
-// These handlers could potentially be defined within
-// configure() blocks to provide introspection when
-// in the development environment.
-
-app.error(function(err, req, res, next){
-  if (err instanceof NotFound) {
-    res.render('404.jade', { status: 404, error: err });
-  } else {
-    next(err);
-  }
-});
-
-// Here we assume all errors as 500 for the simplicity of
-// this demo, however you can choose whatever you like
-
-app.error(function(err, req, res){
-  res.render('500.jade', { status: 500, error: err });
+app.use(function(err, req, res, next){
+  // we may use properties of the error object
+  // here and next(err) appropriately, or if
+  // we possibly recovered from the error, simply next().
+  res.render('500', {
+      status: err.status || 500
+    , error: err
+  });
 });
 
 // Routes
@@ -84,8 +65,14 @@ app.get('/', function(req, res){
   res.render('index.jade');
 });
 
-app.get('/404', function(req, res){
-  throw new NotFound(req.url);
+app.get('/404', function(req, res, next){
+  next();
+});
+
+app.get('/403', function(req, res, next){
+  var err = new Error('not allowed!');
+  err.status = 403;
+  next(err);
 });
 
 app.get('/500', function(req, res, next){

examples/error-pages/views/404.jade

@@ -1,4 +1 @@
-- if (error.path)
-  h2 Cannot find #{error.path}
-- else
-  h2 Page Not Found
+h2 Cannot find #{url}

examples/error-pages/views/index.jade

@@ -5,4 +5,7 @@ ul
     a(href="/500") 500
   li
     | visit
-    a(href="/404") 404
+    a(href="/404") 404
+  li
+    | visit
+    a(href='/403') 403