How to use the middleware to check the authorization before entering each route in express?

Question

I want to check the authorization of the users of my web app when they entered the url. But when I used an individually middleware to check the authorization, it's useless for the already existing routes, such as:

function authChecker(req, res, next) {
    if (req.session.auth) {
        next();
    } else {
       res.redirect("/auth");
    }
}

app.use(authChecker);
app.get("/", routes.index);
app.get("/foo/bar", routes.foobar);

The authChecker is unabled to check the authority of the users who entered the two urls. It only works for the unspecified urls.

And I saw a method that I can put the authChecker between the route and the route handler, such as:

app.get("/", authChecker, routes.index);

But How can I achieve it in a simple way rather than putting the authChecker in every route?

Answer 1

As long as

app.use(authChecker);

is before

app.use(app.router);

it will get called for every request. However, you will get the "too many redirects" because it is being called for ALL ROUTES, including /auth. So in order to get around this, I would suggest modifying the function to something like:

function authChecker(req, res, next) {
    if (req.session.auth || req.path==='/auth') {
        next();
    } else {
       res.redirect("/auth");
    }
}

This way you won't redirect for the auth url as well.