Execute a function before rendering express get router NodeJS - node.js

Question

I want to execute a function each time when the express router is called.
I know I could have placed the function simply inside the app.get function, but I want to call the same function multiple times.
Here is my router.js file:
var Setting = require('../models/setting');
module.exports = function(app, passport) {
// =====================================
// HOME PAGE (with login links) ========
// =====================================
app.get('/', function(req, res) {
Setting.findOne(function(err, setting) {
if (err)
throw err;
// console.log(setting);
res.render('index', { title: 'eduBird | Reach the glory', setting: setting }); // load the index file
});
});
// =====================================
// LOGIN ===============================
// =====================================
// show the login form
app.get('/login', sabSettings, function(req, res) {
// render the page and pass in any flash data if it exists
res.render('login', {
message: req.flash('loginMessage'),
errors: req.flash('error'),
title: 'Login | eduBird',
setting: setting
});
});
// process the login form
app.post('/login', passport.authenticate('local-login', {
successRedirect: '/profile',
failureRedirect: '/login',
failureFlash: true
}));
// =====================================
// SIGNUP ==============================
// =====================================
// show the signup form
app.get('/signup', function(req, res) {
// render the page and pass in any flash data if it exists
res.render('signup', {
message: req.flash('signupMessage'),
errors: req.flash('error'),
title: 'Register | eduBird',
setting: req.setting
});
});
// process the signup form
app.post('/signup', passport.authenticate('local-signup', {
successRedirect: '/profile',
failureRedirect: '/signup',
failureFlash: true
}));
// app.post('/signup', function(req, res) {
// console.log(req);
// });
// =====================================
// PROFILE SECTION =====================
// =====================================
// we will want this protected so you have to be logged in to visit
// we will use route middleware to verify this (the isLoggedIn function)
app.get('/profile', isLoggedIn, sabSettings, function(req, res) {
res.render('profile', {
user: req.user, // get the user out of session and pass to template
title: req.user.local.name + "'s profile | eduBird",
setting: req.setting
});
});
// =====================================
// LOGOUT ==============================
// =====================================
app.get('/logout', function(req, res) {
req.logout();
res.redirect('/');
});
};
// route middleware to make sure a user is logged in
function isLoggedIn(req, res, next) {
// if user is authenticated in the session, carry on
if (req.isAuthenticated())
return next();
// if they aren't redirect them to the home page
res.redirect('/login');
};
function sabSettings(next) {
Setting.findOne(function(err, setting) {
if (err)
throw err;
console.log('sabSetting function executed');
console.log(setting);
console.log('~~~~~~~~~~~');
// return setting;
return next(setting);
});
};
Here I had used an example of isLoggedIn which is executing fine, but the same is not able to work for sabSettings() which would pass all settings config from database to, my /login, /signup, /profile and/or / all the routes.
The console.log(setting) is returning all the data to my console, but I am getting an error stating:
throw er; // Unhandled 'error' event
^
TypeError: next is not a function
at C:\Users\animeshweb\Desktop\projects\eb-v2\routes\routes.js:106:16
You can see that I had embedded a function in app.get('/') for getting the same, but I want this function to be executed wherever I want, so I want a separate function for that.
Update
I update my routes.js as requested:
function sabSettings(req, res, next) {
Setting.findOne(function(err, setting) {
if (err)
next(err);
console.log('sabSetting function executed');
console.log(setting);
console.log('~~~~~~~~~~~');
req.setting = setting;
next();
});
};
I had also made Setting = require(myModelURL) above, which is working fine fo route.get'/'.
*This is my view/layout.pug file`
link(rel='icon', type='image/png', href=setting.logo.logo16 sizes='16x16')
link(rel='icon', type='image/png', href=setting.logo.logo32 sizes='32x32')
link(rel='icon', type='image/png', href=setting.logo.logo128 sizes='128x128')
The same is working fine in adminlayout0.pug
Thanks.

Answer 1

You've declared sabSettings wrong. Middleware is passed three arguments so your declaration should be like this:
function sabSetting(req, res, next) {
// function logic here
}
Since the argument you named next was in the wrong position, it was not a function when you tried to call it.
And, I don't know why you are trying to do return next(setting). That will tell Express that you're reporting an error in the request. If you're trying to put the setting value somewhere that the rest of the request handlers can use it, then you probably want to put it on the req object such as:
req.setting = setting; // put setting on the req object for other code to use
next(); // continue routing
In addition, you should never do a throw err inside a middleware function. That simply won't do anything useful and your request will probably never get finished. Instead, you should handle the error when you get it. You may either branch to some alternate strategy within the middleware when you get an error or you may simply returned a failed request with either next(err) or by doing res.status(500).send(...).
You will then need to change your res.render() to this:
res.render('index', { title: 'eduBird | Reach the glory', setting: req.setting });
The setting variable is now stored on the req object so that's where you need to refer to it.
Change it everywhere you are referring to setting.