Can the callback for facebook-pasport be dynamically constructed? - node.js

Question

When using facebook-passport the usual thing to do is to specify the redirect_uri in the constructor of the FacebookStrategy thst you use, something like this:
passport.use("facebook", new FacebookStrategy({
//TODO: Correctly configure me
clientID: "XXXXXXX"
, clientSecret: "XXXXXXXXX"
, callbackURL: "http://localhost:3007/auth/facebook/callback"
},
function(accessToken,refreshToken,profile,done) {
User.findByFacebookId(profile.id, function(err,user) {
if(err){ return done(err);}
if(!user){ return done(null,false)}
return done(null, user);
});
})
);
Then you would set up routes like this:
app.get('/auth/facebook/login', passport.authenticate('facebook') );
app.get('/auth/facebook/login_callback', passport.authenticate('facebook', {
successRedirect:"/login_ok.html"
, failureRedirect:"/login_failed.html"
}
))
Is it possible to change the callback url so that it contains information from parameters passed to the initial login call?
NOTE: This question is more for preserving info that took me a while to work out, to avoid others going down the same paths.

Answer 1

I found the answer using some info found here https://github.com/jaredhanson/passport-facebook/issues/2 and through digging through the way the passport oauth2 component determines callback uris, and information about passport custom callbacks at the bottom of this page http://passportjs.org/guide/authenticate/.
Here's an example that maps calls to /auth/facebook/login/1234 to use the callback /auth/facebook/login_callback/1234
app.get('/auth/facebook/login/:id', function(req,res,next) {
passport.authenticate(
'facebook',
{callbackURL: '/auth/facebook/login_callback/'+req.params.id }
)(req,res,next);
});
app.get('/auth/facebook/login_callback/:id', function(req,res,next) {
passport.authenticate(
'facebook',
{
callbackURL:"/auth/facebook/login_callback/"+req.params.id
, successRedirect:"/login_ok.html"
, failureRedirect:"/login_failed.html"
}
) (req,res,next);
});

Answer 2

#OMGPOP, here you can pass in query params into your callbackUrl.
var Passport = require('passport');
var FacebookStrategy = require('passport-facebook').Strategy;
const Router = require("express").Router();
var fbConfig = {
display: "popup",
clientID: "YourFbClientId",
clientSecret: "YourFbClientSecret",
callbackURL: "http://localhost:8686/auth/facebook/callback",
profileFields: ['id', 'name', 'gender', 'displayName', 'photos', 'profileUrl', 'email']
}
Passport.use(new FacebookStrategy(fbConfig,
function(accessToken, refreshToken, profile, callback) {
return callback(null, accessToken);
}
));
Router.get("/auth/facebook", function(req, res, next) {
var callbackURL = fbConfig.callbackURL + "?queryParams=" + req.query.queryParams;
Passport.authenticate("facebook", { scope : ["email"], callbackURL: callbackURL })(req, res, next);
});
Router.get("/auth/facebook/callback", function(req, res, next) {
Passport.authenticate("facebook", {
callbackURL: fbConfig.callbackURL + "?queryParams=" + req.query.queryParams,
failureRedirect: "/login",
session: false
})(req, res, next) },
function(req, res) {
console.log(req.query.queryParams);
//do whatever you want
});
Check out my blog for more information: http://blog.pingzhang.io/javascript/2016/09/22/passport-facebook/

Answer 3

I was struggling to do this specifically with Angularjs, and wanted to redirect back to the same url that the login was initiated from.
My solution was to create a route in Angularjs that just implements a location back. I know this does not specifically answer the question, but I thought it would be helpful for anyone looking to do the same.
On the server:
app.get('/auth/facebook/', passport.authenticate ('facebook'));
app.get('/auth/facebook/callback', function (req, res, next) {
var authenticator = passport.authenticate ('facebook', {
successRedirect: '/fbcallback',
failureRedirect: '/'
});
delete req.session.returnTo;
authenticator (req, res, next);
})
Angular router:
when('/fbcallback', {
template: "",
controller: 'fbCtrl'
}).
Angular controller:
app.controller("fbCtrl", function () {
window.history.back();
});
You could probably do some other client side routing in the controller as well.