News

Eclipse RAP 1.0 Brings RCP and OSGi to Ajax

Posted by Craig Wickesser on Oct 17, 2007 09:34 AM

Community: Java
Topics: Web Frameworks
Tags: Eclipse RAP

The Eclipse Foundation released the Eclipse Rich Ajax Platform (RAP) 1.0 on Monday. The Eclipse RAP is an Ajax toolkit for creating and deploying Rich Internet Applications geared towards enterprise developers.

InfoQ had a chance to talk with Jochen Krause, RAP project leader, about this first release. Krause was first asked about how Eclipse RAP compared to other Ajax frameworks and platforms:

RAP is based on Equinox, the OSGi reference implementation. It allows developers to structure applications in components (plug-ins), a feature that has been key for Eclipses success. It also allows developers to use Java as their implementation language and comes with an advanced tooling suite, the well established Eclipses JDT and PDE (Plug-in development environment). Finally, RAP allows single sourcing of desktop clients (with Eclipse RCP) and RIA clients (with RAP).

Ian Skerrett sums up the overall use of RAP:

The neat thing about RAP is that you write Ajax applications in Java and use the Eclipse component model based on OSGi. Think of it something like GWT but using Eclipse plugins. This means you can now architect your Ajax applications as extensible components. For large companies this is a big deal since they typically like to create architectures that help them re-use code in different applications.

As reported on Ajaxian.com:

RAP is very different to something like GWT. RAP runs the logic on the server, and emits JavaScript for the controls at runtime (as opposed to compile-time). An implementation of SWT runs on the server and people can extend your views and perspectives to add functionality.

Although RAP provides the ability to use Java, when asked about support for PHP, Ruby or .NET Krause stated that future support for Ruby, and possibly other languages on the JVM, is feasible. Additionally, the RAP website mentions that RAP provides a subset of the SWT API. When InfoQ asked Krause about the status of RAP's conformance with the full SWT API the response was simple:

very broad coverage

Specifically the following items are currently missing,

GC (Graphical context that enables drawing of the UI (also no graphical editors))
no key events (yet)
no low level mouse events (yet)
no drag&drop (yet)
no StyledText (base for all source code editors in Eclipse)

One hot topic in the Ajax application arena is offline support, such as Google Gears. The Eclipse RAP does not provide offline support but instead, as Krause suggested, Eclipse RCP would be the suitable option.

Finally, InfoQ asked Krause to elaborate on the benefits provided to RAP by its support of Equinox:

Componentization of applications

Equinox is a platform that can be executed on very many platforms: devices, desktops, servers.

Equinox integrates with standard JEE servers (apps can simply be deployed as .war), but apps can also be run standalone.

Some additional information, including screen casts demonstrating the setup and use of Eclipse RAP, can be found at the following links: