app is undefined in loopback custom js file - node.js

Question

i am using nodejs loopback framework.i want to run a cron job.i created a custom js file for this cron job in server/boot folder.but when manually i run this file(xyz). app is undefined.my code is below
var app = require('../server.js');
console.log(">>>>>>>>>>>>>>in test")
var subscription = app.models.UserNotification;
console.log(">>>>>>>>>>>..in manage")
var datasource=subscription.dataSource;
var query="SELECT DISTINCT userId FROM users_subscription";
datasource.connector.query(sql,function (err, data) {
console.log(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>data is>>>>>",data);
})
here is my server.js file
var bodyParser = require('body-parser');
var loopback = require('loopback');
var boot = require('loopback-boot');
var app = module.exports = loopback();
var passport = require('passport');
var bodyParser = require('body-parser').urlencoded({
extended: true
})
app.use(bodyParser)
app.use(loopback.context());
app.use(loopback.token());
var path = require("path");
var url = require('url');
var http = require('http');
var fs = require('fs');
var request = require('request');
app.start = function() {
// start the web server
return app.listen(function() {
app.emit('started');
var baseUrl = app.get('url').replace(/\/$/, '');
console.log('Web server listening at: %s', baseUrl);
if (app.get('loopback-component-explorer')) {
var explorerPath = app.get('loopback-component-explorer').mountPath;
console.log('Browse your REST API at %s%s', baseUrl, explorerPath);
}
});
};
app.use(loopback.static(path.resolve(__dirname, '../client')));
app.use(loopback.static(path.resolve(__dirname, '../admin')));
app.use(loopback.static(path.resolve(__dirname, '../other-dir')));
boot(app, __dirname, function(err) {
if (err) throw err;
if (require.main === module) app.start();
});
Thanks,

Answer 1

It's really impossible to say for sure since you don't include the code that is included with:
var app = require('../server');
(which would be the most important code to include if the require returns undefined) but if app is undefined then it means that the module is loaded but its module.exports is undefined.
Do you export anything from that module?
Are you sure that it is really app that is undefined and not, say, app.models?
Without knowing the code in question those are the most reasonable things to investigate.
Update
If you don't export anything from your server.js (which was my suspection in my answer above, but now you confirmed it with you code and comment) then after this line:
var app = require('../server.js');
you will not be able to use app.models.UserNotification
If you want to use app.models in the code that requires server.js, then you'll have to add:
module.exports.models = SOMETHING;
in your server.js code. You don't seem to have anything called models in server.js, you don't export anything as module.exports.models, so you can't expect app.models to be defined in your code that does:
var app = require('../server.js');