Click here to close now.

Welcome!

Java Authors: Pat Romanski, Plutora Blog, Liz McMillan, Yakov Fain, Tim Hinds

Related Topics: AJAX & REA

AJAX & REA: Article

Model-View-Controller and the Brave New World of Rich Internet Applications

Many Web developers haven't heard of MVC and try to design RIAs like they would design a typical HTML app

Canoo's Web 2.0 Technology Blog on Java, AJAX and Flex

Rich Internet Applications pick up the ball where plain Web applications dropped it: they promise to bring the power of desktop applications to the Web. Desktop applications almost went out of fashion with the advent of Web applications. But most people still prefer the rich user interface (UI) and interactivity of desktop applications such as Outlook compared to their Web-based siblings such as GMail and Yahoo! Mail. In many cases the convenience of ubiquity compensates for the inferior or cumbersome user interface.

MVC diagram

Client-server applications with rich user interfaces first emerged at the beginning of the nineties. Usually implemented in C++ or Smalltalk, they followed a fat-client approach, the predominant client-server architecture at this time. The principal way to organize the presentation layer of such applications was the MVC model. The concept was first proposed by Trygve Reenskaug (see http://heim.ifi.uio.no/~trygver/2007/MVC_Originals.pdf) for the Smalltalk environment. As with any proven object-oriented design, MVC splits up the responsibilities of a user interface component into domain data (Model), rendering (View), and event handling (Controller). Quite often, view and controller are merged together, though.

Today’s GUI component libraries still make use of MVC. For example, most non-trivial UI components in Swing employ some sort of MVC. However, if one tries to apply MVC to complex (form-based) applications, which is typical for desktop or Rich Internet Applications, experience shows that criteria such as clean design, maintainability, or reusability cannot be met. There are several reasons:

  1. What is the model of a form based application with a rich UI? Most developers point to the business object to be rendered in the form as the model. A form-based RIA has more model states than just the business object, though. This additional state is usually kept in the view class and increases the complexity of the view.

  2. The presentation logic of a Rich Internet Application is vastly more complex compared to a traditional Web application. The presentation logic has to deal with more events caused by extended interactivity. Another feature of RIAs is an up-to-date rendering of the presentation state. For example, UI components may be enabled/disabled or visible/invisible depending on the state of the application. This is also part of the additional model state as mentioned above. On top of that, RIAs feature instant validation (without interrupting a user’s flow of work by throwing a modal dialog into their face). This “silent” validation has to be handled (at least partly) by the presentation logic as well. Naïve design puts all of these aspects into the view class. As a result, the view class becomes overly complex, hardly reusable, and difficult to maintain.

  3. Automated testing of such view classes can only be accomplished by running the user interface. Tests are executed by triggering user events through a test tool or accessing the components through a library (e.g. Jemmy for Swing component library). This way of testing is slow and fragile: running hundreds or thousands of UI tests takes quite some time and changes to the user interface are likely to break the tests resulting in false negatives.

As a company specializing in RIA, we at Canoo have witnessed quite a few transitions from plain ugly Web applications to the brave new world of RIA. Some of our observations:

  • Typical Web developers have not heard of MVC and try to design RIAs like they would design a typical HTML application.

  • Seasoned developers who may have had some experience with fat client-server applications try to apply MVC concepts in the same way that they did in the nineties, without adapting to the new scenario.

Both approaches have their weaknesses and lead to poor results. In part two of this blog post series - “The world needs more models” - we will discuss possible remedies to this situation.

More Stories By Bruno Schaeffer

Bruno Schaeffer is Co-Founder & CTO of Canoo Technologies. Since 1997 he has been a Java developer, consultant, and architect. His areas of expertise are Web application platforms and Rich Internet Application technologies.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
SYS-CON Events announced today that GENBAND, a leading developer of real time communications software solutions, has been named “Silver Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. The GENBAND team will be on hand to demonstrate their newest product, Kandy. Kandy is a communications Platform-as-a-Service (PaaS) that enables companies to seamlessly integrate more human communications into their Web and mobile applications - creating more engaging experiences for their customers and boosting collaboration and productiv...
Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been involved at the beginning of four IT industries: EDA, Open Systems, Computer Security and now SOA.
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...
Operational Hadoop and the Lambda Architecture for Streaming Data Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, representing a model of how to analyze rea...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
SYS-CON Events announced today that Open Data Centers (ODC), a carrier-neutral colocation provider, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Open Data Centers is a carrier-neutral data center operator in New Jersey and New York City offering alternative connectivity options for carriers, service providers and enterprise customers.
When it comes to the Internet of Things, hooking up will get you only so far. If you want customers to commit, you need to go beyond simply connecting products. You need to use the devices themselves to transform how you engage with every customer and how you manage the entire product lifecycle. In his session at @ThingsExpo, Sean Lorenz, Technical Product Manager for Xively at LogMeIn, will show how “product relationship management” can help you leverage your connected devices and the data they generate about customer usage and product performance to deliver extremely compelling and reliabl...
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
The IoT market is projected to be $1.9 trillion tidal wave that’s bigger than the combined market for smartphones, tablets and PCs. While IoT is widely discussed, what not being talked about are the monetization opportunities that are created from ubiquitous connectivity and the ensuing avalanche of data. While we cannot foresee every service that the IoT will enable, we should future-proof operations by preparing to monetize them with extremely agile systems.
There’s Big Data, then there’s really Big Data from the Internet of Things. IoT is evolving to include many data possibilities like new types of event, log and network data. The volumes are enormous, generating tens of billions of logs per day, which raise data challenges. Early IoT deployments are relying heavily on both the cloud and managed service providers to navigate these challenges. Learn about IoT, Big Data and deployments processing massive data volumes from wearables, utilities and other machines.
SYS-CON Events announced today that CodeFutures, a leading supplier of database performance tools, has been named a “Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. CodeFutures is an independent software vendor focused on providing tools that deliver database performance tools that increase productivity during database development and increase database performance and scalability during production.
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
“In the past year we've seen a lot of stabilization of WebRTC. You can now use it in production with a far greater degree of certainty. A lot of the real developments in the past year have been in things like the data channel, which will enable a whole new type of application," explained Peter Dunkley, Technical Director at Acision, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Intelligent Systems Services will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Established in 1994, Intelligent Systems Services Inc. is located near Washington, DC, with representatives and partners nationwide. ISS’s well-established track record is based on the continuous pursuit of excellence in designing, implementing and supporting nationwide clients’ mission-critical systems. ISS has completed many successful projects in Healthcare, Commercial, Manufacturing, ...
PubNub on Monday has announced that it is partnering with IBM to bring its sophisticated real-time data streaming and messaging capabilities to Bluemix, IBM’s cloud development platform. “Today’s app and connected devices require an always-on connection, but building a secure, scalable solution from the ground up is time consuming, resource intensive, and error-prone,” said Todd Greene, CEO of PubNub. “PubNub enables web, mobile and IoT developers building apps on IBM Bluemix to quickly add scalable realtime functionality with minimal effort and cost.”
The major cloud platforms defy a simple, side-by-side analysis. Each of the major IaaS public-cloud platforms offers their own unique strengths and functionality. Options for on-site private cloud are diverse as well, and must be designed and deployed while taking existing legacy architecture and infrastructure into account. Then the reality is that most enterprises are embarking on a hybrid cloud strategy and programs. In this Power Panel at 15th Cloud Expo (http://www.CloudComputingExpo.com), moderated by Ashar Baig, Research Director, Cloud, at Gigaom Research, Nate Gordon, Director of T...
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
DevOps tends to focus on the relationship between Dev and Ops, putting an emphasis on the ops and application infrastructure. But that’s changing with microservices architectures. In her session at DevOps Summit, Lori MacVittie, Evangelist for F5 Networks, will focus on how microservices are changing the underlying architectures needed to scale, secure and deliver applications based on highly distributed (micro) services and why that means an expansion into “the network” for DevOps.
With several hundred implementations of IoT-enabled solutions in the past 12 months alone, this session will focus on experience over the art of the possible. Many can only imagine the most advanced telematics platform ever deployed, supporting millions of customers, producing tens of thousands events or GBs per trip, and hundreds of TBs per month. With the ability to support a billion sensor events per second, over 30PB of warm data for analytics, and hundreds of PBs for an data analytics archive, in his session at @ThingsExpo, Jim Kaskade, Vice President and General Manager, Big Data & Ana...