Passport and connect-flash: req.flash is not a function

问题

I'm learning flash messaging in passport and got stuck on this error when running my script:

req.flash is not a function

Here is my configuration:

var flash=require("connect-flash");
app.use(flash());

passport.use(new LocalStrategy(function(req,username, password,done) {
process.nextTick(function() {
    UserDetails.findOne({'username': username}, function(err, user) {
        if (err) {
            return done(err);
        }          
        if (!user) {
            return done(null, false,req.flash('message','Invalid username or password'));
        }
        if (user.password != password) {
            return done(null, false,req.flash('message','Invalid username or password' ));
        }
        return done(null, user);
    });
});
}));

My route:

app.get('/', function (req, res) {
res.render('login',{ message: req.flash('message') });
});

My strategy:

app.post('/login', function(req,res,next){
passport.authenticate('local', function(err, user) {
    if (err) { return next(err); }
    if (!user) { return res.redirect('/')}
    req.logIn(user, function(err) {
        if (err) { return next(err); } 
            arenderFunction(req,res);
        });
    })
(req, res, next);
});

Any help is much appreciated!

回答1:

The request object isn't passed to the strategy callback by default, you need to set the passReqToCallback option for this:

passport.use(new LocalStrategy({
  passReqToCallback : true
}, function(req, username, password, done) { ... }));

This is documented here.

回答2:

Set flash before the app.router

app.use(express.cookieParser()); 
app.use(express.session({ secret: "secret" }));

//app.use(passport.initialize());
//app.use(passport.session()); // persistent login sessions

app.use(flash());
app.use(app.router);

来源：https://stackoverflow.com/questions/34310348/passport-and-connect-flash-req-flash-is-not-a-function