How do I redirect in expressjs while passing some context?

The easiest way I have found to pass data between routeHandlers to use next() no need to mess with redirect or sessions. Optionally you could just call your homeCtrl(req,res) instead of next() and just pass the req and res

var express = require('express'); var jade = require('jade'); var http = require("http"); var app = express(); var server = http.createServer(app); ///////////// // Routing // ///////////// // Move route middleware into named // functions function homeCtrl(req, res) { // Prepare the context var context = req.dataProcessed; res.render('home.jade', context); } function categoryCtrl(req, res, next) { // Process the data received in req.body // instead of res.redirect('/'); req.dataProcessed = somethingYouDid; return next(); // optionally - Same effect // accept no need to define homeCtrl // as the last piece of middleware // return homeCtrl(req, res, next); } app.get('/', homeCtrl); app.post('/category', categoryCtrl, homeCtrl); 

I had to find another solution because none of the provided solutions actually met my requirements, for the following reasons:

• Query strings: You may not want to use query strings because the URLs could be shared by your users, and sometimes the query parameters do not make sense for a different user. For example, an error such as ?error=sessionExpired should never be displayed to another user by accident.

• req.session: You may not want to use req.session because you need the express-session dependency for this, which includes setting up a session store (such as MongoDB), which you may not need at all, or maybe you are already using a custom session store solution.

• next(): You may not want to use next() or next("router") because this essentially just renders your new page under the original URL, it's not really a redirect to the new URL, more like a forward/rewrite, which may not be acceptable.

So this is my fourth solution that doesn't suffer from any of the previous issues. Basically it involves using a temporary cookie, for which you will have to first install cookie-parser. Obviously this means it will only work where cookies are enabled, and with a limited amount of data.

Implementation example:

var cookieParser = require("cookie-parser"); app.use(cookieParser()); app.get("/", function(req, res) { var context = req.cookies["context"]; res.clearCookie("context", { httpOnly: true }); res.render("home.jade", context); // Here context is just a string, you will have to provide a valid context for your template engine }); app.post("/category", function(req, res) { res.cookie("context", "myContext", { httpOnly: true }); res.redirect("/"); } 

use app.set & app.get

Setting data

router.get( "/facebook/callback", passport.authenticate("facebook"), (req, res) => { req.app.set('user', res.req.user) return res.redirect("/sign"); } ); 

Getting data

router.get("/sign", (req, res) => { console.log('sign', req.app.get('user')) }); 

we can use express-session to send the required data

when you initialise the app

const express = require('express'); const app = express(); const session = require('express-session'); app.use(session({secret: 'mySecret', resave: false, saveUninitialized: false})); 

so before redirection just save the context for the session

app.post('/category', function(req, res) { // add your context here req.session.context ='your context here' ; res.redirect('/'); }); 

Now you can get the context anywhere for the session. it can get just by req.session.context

app.get('/', function(req, res) { // So prepare the context var context=req.session.context; res.render('home.jade', context); }); 

Here s what I suggest without using any other dependency , just node and express, use app.locals, here s an example :

 app.get("/", function(req, res) { var context = req.app.locals.specialContext; req.app.locals.specialContext = null; res.render("home.jade", context); // or if you are using ejs res.render("home", {context: context}); }); function middleware(req, res, next) { req.app.locals.specialContext = * your context goes here * res.redirect("/"); } 

Update 2021: i tried url.format and querystring and both of them are deprecated, instead we can use URLSearchParams

const {URLSearchParams} = require('url') app.get('/category', (req, res) =>{ const pathname = '/?' const components ={ a:"a", b:"b" } const urlParameters = new URLSearchParams(components) res.redirect(pathname + urlParameters) }) 

You can pass small bits of key/value pair data via the query string:

res.redirect('/?error=denied'); 

And javascript on the home page can access that and adjust its behavior accordingly.

Note that if you don't mind /category staying as the URL in the browser address bar, you can just render directly instead of redirecting. IMHO many times people use redirects because older web frameworks made directly responding difficult, but it's easy in express:

app.post('/category', function(req, res) { // Process the data received in req.body res.render('home.jade', {error: 'denied'}); }); 

As @Dropped.on.Caprica commented, using AJAX eliminates the URL changing concern.

I use a very simple but efficient technique in my app.js ( my entry point ) I define a variable like

let authUser = {}; 

Then I assign to it from my route page ( like after successful login )

authUser = matchedUser 

It May be not the best approach but it fits my needs.