JavaScript code sample. This is part of a project which allows users to add a new event listing to a website. Project used Node.js and Express.js

add-event-route.js

// for add event page

// these variables are required for each route
var express = require('express');
var router = express.Router();


// GET home page
router.get('/add-event', function(request, response){
        // this refers to the add-event.ejs file in views folder
        response.render('add-event', {
            pageTitle: "Add Your Event",
            pageID: 'add-event' 
        }); // end response
}); //end router

module.exports = router;

add-event.js

// Saves a new event to the database

"use strict";
(function () {
    var userEventsRef = firebase.database().ref("user-events"); 
    var eventsRef = firebase.database().ref("events"); 

    var uploadfile = document.getElementById('evimage');
    

    // listen for file selection, once file is selected save to folder under users uid
    uploadfile.addEventListener('change', function(e) {
        var uidforpics = firebase.auth().currentUser.uid;
        var imgfile = $("#evimage").prop('files')[0];
        var imgref = firebase.storage().ref('listingpics/' + uidforpics + '/' + imgfile.name);
        var progressbar = document.getElementById('uploader');
        
        // upload the image
        var uploadimg = imgref.put(imgfile);
        
        // update progress bar
        uploadimg.on('state_changed',
                     function progress(snapshot) {
            var percent = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
            progressbar.value = percent;
        },
                     function error(err) {

        },
                     function complete() {
            imgref.getDownloadURL().then(function(url){
                var setimgurl = document.getElementById('imgurl');
                // set the value of form field w/URL
                setimgurl.value = url; 
                console.log(setimgurl);
            });
          
        }
        );
    });


    var submitEvent = function () { 
        var userid = firebase.auth().currentUser.uid;
         // Get input values from each of the form elements
        var title = $("#eventtitle").val();
        var description = $("#desc").val();
        var begDate = $("#startdate").val();
        var begTime = $("#starttime").val();
        var finDate = $("#enddate").val();
        var finTime = $("#endtime").val();
        var addrOne = $("#addrlnone").val();
        var addrTwo = $("#addrlntwo").val();
        var place = $("#city").val();
        var post = $("#postcode").val();
        var country = $("#country").val();
        var eventurl = $("#website").val();
        var eventcontact = $("#contactinfo").val();
        var cost = $("#price").val();
        var quantity = $("#quantity").val();
        var category = $("#category").val();
        var picurl = $("#imgurl").val();
        
        // set the data that will be saved in the db
        var newEvent = {  // items on left are db labels right are variable names. 
            "title": title,
            "description": description,
            "startdate": begDate,
            "starttime": begTime,
            "enddate": finDate,
            "endtime": finTime,
            "addressone": addrOne,
            "addresstwo": addrTwo,
            "website": eventurl,
            "contact": eventcontact,
            "city": place,
            "country": country,
            "postcode": post, 
            "price": cost,
            "quantity": quantity,
            "category": category,
            "image": picurl, 
            "uid": userid
            };
        
        // pushes data to the user-events collection in Firebase database
        var newEventRef = userEventsRef.push(newEvent);

        // adds data to events collection with same push key
        eventsRef.child(newEventRef.key).set(newEvent);

    };  // end submitEvent function


        $(window).load(function () {
          $("#listingform").submit(submitEvent);
        }); // end window load

    
})(); // end file wrapper