Redirect loop with node express.js - node.js

Question

I have simple webpage with /about, /contact, /home and /lessons routes defined. All routes work okay except for /lessons. I instantly get a redirect loop (Error 310 (net::ERR_TOO_MANY_REDIRECTS): There were too many redirects).
Here's my main server.js code :
var port = process.env.PORT || 8888;
var app = require('./app').init(port);
var markdown = require('./markdown');
var lessons = require('./lessons.json').lessons;
// app.use(function(req,res,next) {
// console.log('adding lessons to locals');
// res.locals.date = new Date().toLocaleDateString();
// res.locals.lessons = lessons;
// next();
// });
// app.use(app.router);
app.get('/', function (req, res) {
console.log('controller is : home');
res.locals.controller = 'home';
res.render('home');
});
app.get('/:controller', function (req, res, next) {
var controller = req.params.controller;
console.log('controller is : '+ controller);
if (controller == 'about' || controller == 'contact') {
res.locals.controller = controller;
res.render(controller);
} else {
console.log('next was taken!');
next();
}
});
app.get('/lessons', function(req, res) {
res.locals.lessons = lessons;
console.log('controller is : lessons');
res.render('lessons');
});
app.get('/lessons/:lesson', function(req, res) {
console.log('controller is : lesson');
res.locals.controller = 'lessons';
res.send('gimmie the lesson');
});
/* The 404 Route (ALWAYS Keep this as the last route) */
app.get('/*', function (req, res) {
console.log('got 404 request to ' + req.url);
res.render('404');
});
and here's the app.jsfile which is used for server initialization:
var express = require('express');
var slashes = require('connect-slashes');
exports.init = function (port) {
var app = express();
app.use(express.static(__dirname + '/public'));
// add middleware to remove trailing slash in urls
app.use(slashes(false));
app.set('views', __dirname + '/views')
app.set('view engine', 'ejs');
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(express.logger());
app.enable("jsonp callback");
if ('development' == app.get('env')) {
app.use(express.errorHandler({
dumpExceptions: true,
showStack: true
}));
app.use(express.logger({
format: ':method :url'
}));
}
if ('production' == app.get('env')) {
app.use(express.errorHandler());
}
app.use(function (err, req, res, next) {
console.log('Oops, something went wrong');
res.render('500.ejs', {
locals: {
error: err
},
status: 500
});
});
app.listen(port);
console.log("Listening on port %d in %s mode", port, app.settings.env);
return app;
}
I have tried debugging the app with node-inspector but it's useless since the app doesn't seem to go into any of the app.gets to try to match. It immidiately gives me the error when I try to access localhost:8888/lessons
EDIT:
I think I have found the root of the problem :
My /public dir has a lessons folder
My /views dir has a lessons.ejs view
When I change /public/lessons into /public/lessons11 for example, the problem is resolved. Can someone explain to me what's express flow in the original scenario that causes the redirect loop ? also, what can I do to resolve it ?
Thanks

Answer 1

This happens:
a request for /lessons comes in;
the static middleware sees the public/lessons folder and assumes that's what the intended target is; because it's a folder, it will generate a redirect to /lessons/ (see below);
static middleware picks that request up again, but notices there's no index.html in that folder, and hands it off to the next middleware (connect-slashes);
the connect-slashes middleware removes the trailing slash and issues a redirect to /lessons;
the whole loop starts again;
You can prevent the static middleware from adding a trailing slash, which will fix your redirect loop I think:
app.use(express.static(__dirname + '/public', { redirect : false }));

Answer 2

You can try using express-redirect-loop middleware. It uses sessions and you can read more about it and implement it at https://github.com/niftylettuce/express-redirect-loop.