Machine Learning Authors: Yeshim Deniz, William Schmarzo, Flint Brenton, Pat Romanski, Rene Buest

Blog Feed Post

ECMAScript 6 modules in the browser with Traceur

ECMAScript 6 standardizes the syntax of modules. A module is simply a Javascript file that you can load either on the application startup or lazily on the as-needed basis. ES6 modules give you complete control on what code to export to the external scripts and what to keep private to the module. Prepend a variable, a function, or a class definition with the keyword export, and all other scripts in your project can import the module’s API using the import keyword. For details of using modules, read this great post by Dr. Alex Rauschmayer.

But the ECMAScript 6 specification doesn’t define module loaders, which can be used both in the browsers and in the standalone JavaScript engines. Eventually all Web browsers will support the System object that knows how to import modules, but meanwhile you can use the polyfill ES6 Module Loader or, if you want to go fancy and ensure that your AMD and/or CommonJS modules are also loaded in a standardized fashion, go with the universal system module loader called SystemJS.

Since ES6 syntax is not fully supported by any of the modern browsers, you’d need to transpile the code from ES6 to ES5 using one of the transpilers such as Traceur or Babel. In this blog I’ll show you how to dynamically load ES6 modules in the Web browsers with auto-transpiling using Traceur. To run this example on your computer you’ll need to have node.js with npm installed.

First, you need to download and install es6-module loader in any directory by running the following npm command:

npm install es6-module-loader

Then create an application folder and copy the file es6-module-loader.js there (this is a minimized version of the loader that was downloaded by npm). Our sample application will have two additional files: moduleLoader.html and shipping.js. For simplicity I’ll keep all these files in the same folder.

Imagine that we develop an online store with a large code base. To avoid creating a monolithic application, we’ve split it into loadable modules. In particular, the module that handles shipping should be loaded only if the user clicks the Shipping button. Here’s the code of our “huge” shipping module:

export function ship() {
    console.log("Shipping products...");

function calculateShippingCost(){
    console.log("Calculating shipping cost");

Since I used the export keyword only in front of the ship() function, the function calculateShipptingCost() will remain private for the module and won’t be accessible from the outside. No need to implement the module design pattern with immediately-invoked function expressions, and no need to use a third-party framework like RequireJS.

The file moduleLoader.html includes a script that loads and uses the shipping module. In this example I use Traceur for the on-the-fly transpiling of the ES6 code to ES5 so it can run in any browser. Here’s the file moduleLoader.html:

<!DOCTYPE html>
    <script src="https://google.github.io/traceur-compiler/bin/traceur.js"></script>
    <script src="es6-module-loader.js"></script>

  <button id="shippingBtn">Load the Shipping Module</button>


let btn = document.querySelector('#shippingBtn');
btn.addEventListener('click', () =>{

         .then(function(module) {
             console.log("Shipping module Loaded ", module);


             module.calculateShippingCost();  // will throw an error
             console.log("In error handler", err);



in Line 5 we load the Traceur for transpiling. In line 6 we load es6-module-loader to support the System object that will load the shipping module using the import() call when the user clicks on the button. The import returns the ES6 Promise object, and when the module is loaded, the function specified in then() will be executed. In case of an error the control goes to the function catch().

Inside the then() we print the message on the console and invoke the exported function ship(). After that we try to invoke the module’s function calculateShippingCost(), which will result in error because this function was not exported and remain private.

NOTE: When you have the inline script in the HTML file, you should use type="module" to make sure that the Traceur transpile it to ES5. Without it, the browser that don’t support the let keyword (line 14) and arrow functions (line 15) would complain.

To see this code in action you need to serve it using some Web server. I use WebStorm IDE for development, which comes with embedded Web server. Lets run moduleLoader.html in Google Chrome and open Chrome Developer Tools. This is my Chrome browser looks after I clicked on the button Load the Shipping Module:


Look at the XHR tab in the middle of the window. The HTML page has loaded shipping.js after I clicked on the button. The size of this file is 91 bytes, which is really small and making an additional network call to get it seems like an overkill. But if the application consists of 10 modules 500KB each, modularization with lazy loading makes sense.

At the bottom, on the console tab you see the message from the script in moduleLoader that the shipping module was loaded. Then it calls the function from ship() from the shipping module, and generates an error trying to call the function calculateShippingCost() as expected.

In the real-world projects you should integrate transpiling in the project build, but I just wanted to illustrate the ease of the transpiling in the Web browser without any additional preparations. Transpilers allow you to start programming in ECMAScript today. If you live in the New York Area, I invite you to enroll into my one day Intro to JavaScript workshop.

Read the original blog entry...

More Stories By Yakov Fain

Yakov Fain is a Java Champion and a co-founder of the IT consultancy Farata Systems and the product company SuranceBay. He wrote a thousand blogs (http://yakovfain.com) and several books about software development. Yakov authored and co-authored such books as "Angular 2 Development with TypeScript", "Java 24-Hour Trainer", and "Enterprise Web Development". His Twitter tag is @yfain

@CloudExpo Stories
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities - ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups.
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City. Digital Transformation (DX) is a major focus with the introduction of DXWorldEXPO within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term.
To Really Work for Enterprises, MultiCloud Adoption Requires Far Better and Inclusive Cloud Monitoring and Cost Management … But How? Overwhelmingly, even as enterprises have adopted cloud computing and are expanding to multi-cloud computing, IT leaders remain concerned about how to monitor, manage and control costs across hybrid and multi-cloud deployments. It’s clear that traditional IT monitoring and management approaches, designed after all for on-premises data centers, are falling short in ...
With privacy often voiced as the primary concern when using cloud based services, SyncriBox was designed to ensure that the software remains completely under the customer's control. Having both the source and destination files remain under the user?s control, there are no privacy or security issues. Since files are synchronized using Syncrify Server, no third party ever sees these files.
Mobile device usage has increased exponentially during the past several years, as consumers rely on handhelds for everything from news and weather to banking and purchases. What can we expect in the next few years? The way in which we interact with our devices will fundamentally change, as businesses leverage Artificial Intelligence. We already see this taking shape as businesses leverage AI for cost savings and customer responsiveness. This trend will continue, as AI is used for more sophistica...
"We are an integrator of carrier ethernet and bandwidth to get people to connect to the cloud, to the SaaS providers, and the IaaS providers all on ethernet," explained Paul Mako, CEO & CTO of Massive Networks, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
I believe that this may finally be the year that the CIO role ‘crosses the Rubicon,' leaving behind its traditional, IT-focused orientation. But I don't believe that either of the previous predictions of this outcome — fading into oblivion or rising to a business executive level — is correct. Instead, I think this is the year that we will see the role of the CIO transformed into something altogether different.
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
"Calligo is a cloud service provider with data privacy at the heart of what we do. We are a typical Infrastructure as a Service cloud provider but it's been designed around data privacy," explained Julian Box, CEO and co-founder of Calligo, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"NetApp is known as a data management leader but we do a lot more than just data management on-prem with the data centers of our customers. We're also big in the hybrid cloud," explained Wes Talbert, Principal Architect at NetApp, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Andi Mann, Chief Technology Advocate at Splunk, is an accomplished digital business executive with extensive global expertise as a strategist, technologist, innovator, marketer, and communicator. For over 30 years across five continents, he has built success with Fortune 500 corporations, vendors, governments, and as a leading research analyst and consultant.
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
CI/CD is conceptually straightforward, yet often technically intricate to implement since it requires time and opportunities to develop intimate understanding on not only DevOps processes and operations, but likely product integrations with multiple platforms. This session intends to bridge the gap by offering an intense learning experience while witnessing the processes and operations to build from zero to a simple, yet functional CI/CD pipeline integrated with Jenkins, Github, Docker and Azure...
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Sanjeev Sharma Joins November 11-13, 2018 @DevOpsSummit at @CloudEXPO New York Faculty. Sanjeev Sharma is an internationally known DevOps and Cloud Transformation thought leader, technology executive, and author. Sanjeev's industry experience includes tenures as CTO, Technical Sales leader, and Cloud Architect leader. As an IBM Distinguished Engineer, Sanjeev is recognized at the highest levels of IBM's core of technical leaders.