node.js synchronous function call for authentication - node.js

Question

i am completely newbie in node.js, and trying learn how it actually works. I know that by default all node.js function calls are asynchronous. Now i need LDAP authentication in my application where i need wait for the server response to check whether the user credentials are right or wrong.The ldap part is working fine but i am not sure on how to return data from a function call in synchronous way. below is the part of my code.
router.js
var express = require('express');
var router = express.Router();
var tools = require('./authenticateUser');
router.post('/authenticateUser', function(req, res) {
// In the below line i am calling the method which
// should return the userDN (a string)
tools.searchUser(req.body.user, req.body.passwd);
res.render('home.jade');
});
authenticateUser.js
module.exports = {
searchUser : function (username, password) {
adminDN = *************;
adminPassword = '*********';
baseDN = '***';
var ldap = require('ldapjs');
process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
var adminClient = ldap.createClient({
url: '*******'
});
var opts = {
filter: '(&(objectClass=userProxyFull)(sAMAccountName=' + username + '))',
scope: 'sub',
attribute: ['sAMAccountName']
};
console.log('--- going to try to connect user ---');
try {
adminClient.bind(adminDN, adminPassword, function (error) {
if (error) {
console.log(error.message);
adminClient.unbind(function (error) {
if (error) {
console.log(error.message);
} else {
console.log('adminClient disconnected');
}
});
} else {
// Searching Client ID in LDS
adminClient.search(baseDN, opts, function (error, search) {
console.log('Searching.....' + userDN);
search.on('searchEntry', function (entry) {
if (entry.object) {
// Here i need to return the object back
//to the router.js from where i call in a synchronous way
adminClient.unbind(function (error) {
if (error) {
console.log(error.message);
}
});
}
});
search.on('error', function (error) {
console.error('error: ' + error.message);
});
});
}
});
} catch (error) {
console.log(error);
adminClient.unbind(function (error) {
if (error) {
console.log(error.message);
} else {
console.log('client disconnected');
}
});
} finally {
adminClient.unbind(function (error) {
if (error) {
console.log(error.message);
} else {
console.log('client disconnected');
}
});
}
},
};

Answer 1

You have to pass res.render('home.jade') as a function(the callback) to your searchUser function.
It should look like
tools.searchUser(req.body.user,
req.body.password,
res}
)
searchUser function
searchUser : function (username, password,res) {
...
finally(){
res.render('home.jade');
}
}