How can I pass a parameter through my passport.js chain?

javascript, passport.js

Solution

You can pass a state object to passport.authenticate, like so:

passport.authenticate("google",
{
    scope:
    [
        "https://www.googleapis.com/auth/userinfo.profile",
        "https://www.googleapis.com/auth/userinfo.email"
    ],
    state: request.query.username
})(request, response);

You can access the state through req.query.state.

The username should be a string, not an object. If you want to store an object in the state, call JSON.stringify before and parse it in the callback.

Problem

I'm using passport.js to authenticate users. I would like to be able to pass a username, collected from the user, which will reach the end of the authentication process so that I can store the username when I create the user (if it doesn't yet exist). I've tried this: ``` app.get("/auth/google", function(request, response) { console.log(request.query.username); passport.authenticate("google", { scope: [ "https://www.googleapis.com/auth/userinfo.profile", "https://www.googleapis.com/auth/userinfo.email" ] })(request, response); }); app.get("/auth/google/callback", function(request, response) { console.log(request.query.username); passport.authenticate("google", { successRedirect: "/", failureRedirect: "htm/error" })(request, response); }); ``` The call to /auth/google prints the username, but the callback prints undefined. Even if I could get the username to the callback, I'm still not sure how I would get it to the google strategy. Would I then have to create my own strategy to get this to work?

Original source