Revision as of 07:01, 17 July 2013

Eclipse Scout adds Mobile Support

Eclipse Scout is a framework to build business applications based on the Eclipse platform. So far, Scout client applications included support for Swing or SWT to build desktop applications, and Eclipse RAP for web applications.

New with the Kepler release, Scout has added support for creating mobile applications that run on tablets and smart phones. Thanks to the clean separation of the Scout application model from a specific UI technology Scout applications may now be deployed on mobile phones, as web applications or to the desktop with a single code base. This feature greatly reduces maintenance costs for larger applications that need to be available on multiple frontends.

Below, a mid-sized Scout business application (20'000 Java classes) is shown. This application takes advantage of Scout's mobile support and can be deployed to desktop and mobile frontends simultaneously.

The rendering of the UI is adapted to the different target devices at runtime. For this, a device transformer component takes care of adapting UI elements to a specific frontend. Examples being context menus that are replaced with touch buttons for mobile devices and tables that are mapped to lists with finger scrolling support.

For the application shown above, less than 20 Java classes are specifically built for the mobile client. These classes are mainly responsible for the application's home screen and the telephony integration on mobile phones. In addition, 200 minor frontend specific adaptations are included in the code base of the product. This results in over 98% of the Java code beeing reused across the different frontends.

Being independent of specific UI technologies is clearly one of Scout's major assets. As an additionaly benefits, it reduces the long term risks of "marrying" critical business applications to the "wrong" UI technology to almost zero. In fact, the default setup of Scout applications enforces the separation of business code from UI technology codes.

The scope of the Scout framework is best shown using a layered setup typical for enterprise IT landscapes. Many well established open source frameworks exist to deal with data access, persistence and the implementation of backend systems up to the business service layer.

On top of a business service layer, Scout applications cover the area from the application layer up to the UI layer as shown above. In this domain, Scout covers most of the recurring aspects of business applications such as UI modeling and rendering including dozens of UI components, data binding, client server communication, authentication and authorization, and server services.

Scout's runtime functionality already makes application developers more efficient. However, the Eclipse Scout package also includes a comprehensive tooling component, the Scout SDK. Working with the Scout SDK increases the productivity of Scout developers even further. And at the same time, learning Scout is made as simple as possible with the Scout SDK.

As this text has been written for software developers without prior knowledge of Scout we want to provide a hands-on introduction based on the Scout package in the reminder of this article.

The Hello World

A "Hello World" program is a traditional way to begin any new framwork or programming language. The special aspect of the Scout "Hello World" is it's client server architecture including clients that runs on the desktop, in a web browser, and on mobile devices.

In the text below we will first introduce the "Hello World" from the user perspective before we go through the installation process and dive into the actual implementation.

What the User sees

When the user starts a client desktop application he/she gets either a Swing or SWT based application showing a "hello world!" message in the main frame of the application. To run the Hello World as a web application in a browser, the user can also type the URL to the application into the address bar of a web browser. As shown below, the user has the choice between three different client applications.

To demonstrate the new mobile Support shipped with the Kepler relase of Scout, the user can also type the application's URL into a mobile browser. Depending on the frontend device used, the user is redirected to specific links for mobile phones or tablets.

When we compare the Hello World web application with the mobile version shown above the slight differences between the two frontends become apparent. On the mobile device the label of the message field is rendered on top of the text and instead of a Tools button that provides access to the applications menu tree we just have a logout button on the mobiles home form.

Installing Scout

Installing the Eclipse for Scout Developers package is no different from installing any other Eclipse package. The Scout package is available on eclipse.org/downloads and the only prerequisite for the installation is a working JDK version 6 or 7.

In case you prefer to go through detailed installation instructions, have a look at these pages.

The Implementation

Begin the implementation of the Hello World application with starting your Eclipse Scout executable and providing an empty workspace directory.

Once Eclipse has started click away the welcome screen and you see the Scout perspective with its two specific views Scout Explorer and Scout Object Properties

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Next Steps

In case you have been intrigued by what you have seen from Scout so far you might consider the following steps

Do more tutorials. In addition to the Hello World tutorial presented above, a significant amount of additional tutorials and how-tos is available on the Scout wiki. Depending on your time and interest, this will keep you occupied an addtional hour - or several days. In case you run into difficulties or have general questions regarding Scout we are happy to answer your questions in the Scout forum. Please bear in mind that July and August is summer vacation time and we are less responsive during these months.

Browse the Book. A more comprehensive introduction is available in the Scout book, also new with the Kepler release. So far, the book provides a good introduction and a general overview of the possibilities of Scout applications. For the next releases we plan to add more material to the book that cover various aspects of Scout and the development of Scout applications in greater detail. The Scout book is free and available in HTML format for online browsing. For offline usage the book is availabe in PDF, EPUB and ZIP (zipped HTML) formats.

Follow Scout. For more recent updates, check out the Scout blog or the @EclipseScout Twitter account. If you happen to live near Zurich also have a look at the local Eclipse Community page on Google+. This is the place where we usually announce public Eclipse events that frequently include Scout presentations.