examples/error-pages/index.js
'use strict'
/**
* Module dependencies.
*/
var express = require('../../');
var path = require('path');
var app = module.exports = express();
var logger = require('morgan');
var silent = process.env.NODE_ENV === 'test'
// general config
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
// our custom "verbose errors" setting
// which we can use in the templates
// via settings['verbose errors']
app.enable('verbose errors');
// disable them in production
// use $ NODE_ENV=production node examples/error-pages
if (app.settings.env === 'production') app.disable('verbose errors')
silent || app.use(logger('dev'));
// Routes
app.get('/', function(req, res){
res.render('index.ejs');
});
app.get('/404', function(req, res, next){
// trigger a 404 since no other middleware
// will match /404 after this one, and we're not
// responding here
next();
});
app.get('/403', function(req, res, next){
// trigger a 403 error
var err = new Error('not allowed!');
err.status = 403;
next(err);
});
app.get('/500', function(req, res, next){
// trigger a generic (500) error
next(new Error('keyboard cat!'));
});
// Error handlers
// Since this is the last non-error-handling
// middleware use()d, we assume 404, as nothing else
// responded.
// $ curl http://localhost:3000/notfound
// $ curl http://localhost:3000/notfound -H "Accept: application/json"
// $ curl http://localhost:3000/notfound -H "Accept: text/plain"
app.use(function(req, res, next){
res.status(404);
res.format({
html: function () {
res.render('404', { url: req.url })
},
json: function () {
res.json({ error: 'Not found' })
},
default: function () {
res.type('txt').send('Not found')
}
})
});
// 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.
// 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.
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.status(err.status || 500);
res.render('500', { error: err });
});
/* istanbul ignore next */
if (!module.parent) {
app.listen(3000);
console.log('Express started on port 3000');
}