How to render route before rendering static files in node js? - node.js

Question

I want to render app.use('/', callback function) before rendering the static files from public folder.
Basically I am doing the authentication before accessing the website, so once it gets authenticated it should load the index.html (static file) from the public folder.
How should i do it?
I am using W3ID from IBM to authenticate the site.
const express = require('express');
const session = require('express-session');
const passport = require('passport');
const WebAppStrategy = require("ibmcloud-appid").WebAppStrategy;
const CALLBACK_URL = "public/index.html";
var path = require('path');
var bodyParser = require('body-parser');
var port = process.env.VCAP_APP_PORT || 8080;
var mongoose = require('mongoose');
//var MongoStore = require('connect-mongo')(session);
const app = express();
// mongodb connection
mongoose.connect("mongodb://admin:admin123#ds261430.mlab.com:61430/events");
var db = mongoose.connection;
// mongo error
db.on('error', console.error.bind(console, 'connection error:'));
// parse incoming requests
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(express.static(path.join(__dirname, 'public')));
app.set('views', path.join(__dirname, 'views'));
// Set view engine as EJS
app.engine('html', require('ejs').renderFile);
app.set('view engine', 'html');
// include routes
app.use(session({
secret: "123456",
resave: true,
saveUninitialized: true
}));
app.use(passport.initialize());
app.use(passport.session());
passport.use(new WebAppStrategy({
tenantId: "73585f35-8d9c-4f6f-9ab2-d07ca0c1d371",
clientId: "863fce57-a717-4586-b8a2-0bf221ef4e68",
secret: "MzkxMTMxMWMtNmYxNi00ZjNhLWFiNzctZjFlM2NkMDM1ZTkz",
oauthServerUrl: "https://appid-oauth.eu-gb.bluemix.net/oauth/v3/73585f35-8d9c-4f6f-9ab2-d07ca0c1d371",
redirectUri: "https://csi.eu-gb.mybluemix.net/" + CALLBACK_URL
}));
passport.serializeUser(function(user, cb) {
cb(null, user);
});
passport.deserializeUser(function(obj, cb) {
cb(null, obj);
});
app.get(CALLBACK_URL, passport.authenticate(WebAppStrategy.STRATEGY_NAME));
app.use('/',passport.authenticate(WebAppStrategy.STRATEGY_NAME), function(req, res) {`enter code here`
// do your authentication
});
// listen on port 8080
app.listen(port);

Answer 1

You can do this by just putting your app.use('/',...) above the app.use('/',express.static('...')).
Or
You can do this by passing option {index:false} to express.static like
app.use('/',express.static('path here',{index:false}));
This option will set express.static to not send the index.html by default.