Welcome!

Industrial IoT Authors: Elizabeth White, Stackify Blog, Yeshim Deniz, SmartBear Blog, Liz McMillan

Blog Feed Post

Modularized JavaScript with JBoss Portal Platform 6 – Avoid Conflicts, Promote Re-usability

JBoss Portal Platform 6

JBoss Portal Platform 6 Beta is now available.
http://www.redhat.com/promo/jpp6/

Many new features are documented there:

  • Built on blazingly fast, lightweight JBoss Enterprise Application Platform 6 technology
  • Develop with JSF2 and Rich Faces 4 in portlets, via Portlet Bridge
  • Implement single sign-on (SSO) using SAML 2.0
  • Launch fast with Maven quick starts

Portlet and JavaScript

However, to developers and architects, one of the first issues and most difficult issue we face in any portal implementation is – what are the best practices to use JavaScripts in a portal platform?

Imagine if you have 2 portlets both using a shared JavaScript, such as jQuery – how would you share the JavaScript between the 2 portlets?

  • Each Portlet include its own
    • This is largely a no-no.  If each portlet include its own jQuery in a <script> tag, they’ll most likely run into conflicts or unnecessarily reload a script already loaded.
  • Deploy a single version
    • Then what if you need multiple versions?
    • What if some portlets needs a different version of the JavaScript library?

Now, expand this dilemma to not just common JavaScripts libraries, but to all of your application’s JavaScripts!

Oh, and don’t forget, you may also want to minify and combine scripts to reduce latency, to be Content Delivery Network (CDN) friendly, and ultimately, to improve your customer’s browsing  experience.

How JBoss Portal Platform 6 Helps

JBoss Portal Platform 6 has an exciting new feature to deal with the age old question of how to best deal with JavaScripts in Portlets.

  • JavaScript should be modular and re-usable
  • Dependency management – if a JavaScript depends on another JavaScript, it should load it automatically
  • Each portlet should be able to specify what JavaScript it needs to use
  • If the Portal Platform already provides certain JavaScript libraries, your portlet should still be able to use other versions.  Multiple versions should not cause issues.
  • Work with JavaScripts you already have

All of the above can be accomplished with JBoss Portal Platform 6!  Best of all, it can be achieved using XML-based configurations as well as using JavaScripts to load JavaScript modules.

JavaScript Modules

JBoss Portal Platform 6 fully embraces the concept of JavaScript modules.  For example, you can define a module named “jquery-1.9.0″ to be associated with jquery-1.9.0.js.

Each module definition contains a name, and JavaScript multiple JavaScript files.  For example:

<module>
    <name>jquery-1.9.0</name>
    <script>/javascript/jquery-1.9.0.js</script>
</module>

Note that, JBoss Portal Platform 6 already ships with a module named “jquery” that provides jQuery 1.7.1.  But it’s OK to define another module using a different name.

Dependencies

A JavaScript module can have dependencies to another JavaScript module.  For example, if your application JavaScript “version.js” depends on jQuery:

(function($) {
    alert($().jquery); // Display jQuery version in an alert window.
})($);

First, we can associate the JavaScript with the portlet, so that JBoss Portal Platform 6 can load “version.js” only if the portlet is also on the page, and then specify the dependency:

<portlet>
    <name>jquery-version</name>
    <module>
        <script>
            <path>/javascript/version.js</path>
        </script>
        <depends>
            <module>jquery</module>
        </depends>
    </module>
</portlet>

* JBoss Portal Platform 6 provides jQuery 1.7.1 as a module.  It can be referenced and re-used by any portlet.

You can, of course, specify multiple dependencies.

Multiple Versions?  No Problem!

What if your portlet needs newest jQuery 1.9.0, even though JBoss Portal Platform already has jQuery 1.7.1?  Not to worry – it’s as easy as changing out the dependency!

<portlet>
    <name>jquery-version</name>
    <module>
        <script>
            <path>/javascript/version.js</path>
        </script>
        <depends>
            <module>jquery-1.9.0</module>
        </depends>
    </module>
</portlet>

In fact, you can even use both versions at the same time.

<portlet>
    <name>jquery-version</name>
    <module>
        <script>
            <path>/javascript/version-both.js</path>
        </script>
        <depends>
            <module>jquery</module>
            <as>jq17</as>
        </depends>
        <depends>
            <module>jquery-1.9.0</module>
            <as>jq19</as>
        </depends>
    </module>
</portlet>

The “<as/>” tag will create an alias for the JavaScript so that it can be referred to by the consuming script.  In the above example, out-of-the-box jQuery is now aliased as “jq17″, and our own version is aliased as “jq19″.  These will then be accessible by the consuming script as variables with those names.

And for “version-both.js”:

(function(jq17, jq19) {
    alert(jq17().jquery); // Display jQuery version in an alert window.
    alert(jq19().jquery);
})(jq17, jq19);

Adapter

What if the JavaScript is not already wrapped by a factory function, e.g. (function(…) { … })(…);

E.g., “version-legacy.js”:

alert($().jquery);

With Adapter, you can wrap existing JavaScripts files with any JavaScript fragments before and after the file:

<portlet>
    <name>jquery-version-legacy</name>
    <module>
        <script>
            <adapter>
                (function($){
                <include>/javascript/version-legacy.js</include>
                })(jq19);
            </adapter>
        </script>
        <depends>
            <module>jquery-1.9.0</module>
            <as>jq19</as>
        </depends>
    </module>
</portlet>

In case you already have many JavaScript files you want to re-use and don’t want to make extensive changes, or if a third-party library needs to be re-wrapped with JavaScript best practices, then Adapter is your friend.

Magic Behind the Scene

How can JBoss Portal Platform 6 accomplish all this?  The magic behind the scene is that JBoss Portal Platform 6 fully embraces Asynchronous Module Definition (AMD).  Behind the scenes, JBoss Portal Platform 6 translates the XML configurations into AMD friendly JavaScript.  For example, when loading both jQuery versions, JBoss Portal Platform 6 will generate the following JavaScript fragment:

define('PORTLET/jquery-portlet/jquery-portlet', ["SHARED/jquery","SHARED/jquery-1.9.0"], function(jq17,jq19) {
    var require = eXo.require, requirejs = eXo.require,define = eXo.define;
    eXo.define.names=["jq17","jq19"];
    eXo.define.deps=[jq17,jq19];
    return (function() {
        alert("jq17().jquery);
        alert("jq19().jquery)
    })(jq17, jq19);
});

Minify, Last-Modified

Last, if not least, JBoss Portal Platform 6 will automatically combine all of the JavaScripts in a single module and then minify the script.  This will not only reduce the size of the JavaScript, it will also reduce the number of files the user’s browser will need to download!  The minified resource will also have proper cache headers, such as Cache-Control and Last-Modified headers to reduce unnecessary re-download of the script and making it more CDN friendly.

Architecting Your Portal with JavaScript in Mind

With these enhancements to JBoss Portal Platform 6, it’s now possible to modularize your JavaScripts, apply dependency management, promote re-usability, and not to worry about the nitty gritty details behind the scenes.  It also opens up a number of possibilities such as deploying JavaScript libraries in a dedicated archive (.war), and portlets packaged in other archives can also reference and re-use the JavaScript.  If you need to upgrade the shared JavaScript code, you can simply deploy the archive containing the new script.

The Code

The examples in this article can be found on github.
https://github.com/saturnism/code-in-blogs/tree/master/jpp6-js-example

There are also plenty more examples in GateIn Community Project.
https://github.com/gatein/gatein-portal/tree/master/examples/portlets
(amd-js, jquery, and todomvc)


Read the original blog entry...

More Stories By Daniel Thompson

I curate the content on this page, but the credit goes to my talented colleagues for the posts that you see here. Much of what you read on this page is the work of friends at How to JBoss, and I encourage you to drop by the site at http://www.howtojboss.com for some of the best JBoss technical and non-technical content for developers, architects and technology executives on the Web.

IoT & Smart Cities Stories
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
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 ...
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
Cell networks have the advantage of long-range communications, reaching an estimated 90% of the world. But cell networks such as 2G, 3G and LTE consume lots of power and were designed for connecting people. They are not optimized for low- or battery-powered devices or for IoT applications with infrequently transmitted data. Cell IoT modules that support narrow-band IoT and 4G cell networks will enable cell connectivity, device management, and app enablement for low-power wide-area network IoT. B...
The hierarchical architecture that distributes "compute" within the network specially at the edge can enable new services by harnessing emerging technologies. But Edge-Compute comes at increased cost that needs to be managed and potentially augmented by creative architecture solutions as there will always a catching-up with the capacity demands. Processing power in smartphones has enhanced YoY and there is increasingly spare compute capacity that can be potentially pooled. Uber has successfully ...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
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...