System iNetwork

Eclipse RCP clients for Application - 1

February 25, 2007

Preparing the ground -- the RPG and Java groundwork for discussing Eclipse RCP clients. Consider what needs to be done ...

So what if WDSc is a compelling demonstration of Eclipse's power build System i clients? Most of us are not paid to develop programming and management tools for the System i. We develop and maintain applications! Our concerns is what can Eclipse RCP do for our applications.

The end goal of the coming series of blog entries is to build Eclipse RCP client applications as a GUI front end for a System i application. But what needs to be done before developing a client for an application -- with or without Eclispe? To reach the goal, discussing Eclipse RCP client, these steps have to have been completed:
- describe a client-server model (MVC)
- create a demonstration server server for the System i using data queues
- create a test client for the System i
- explore data queues in Java through Java applications (not Eclipse or RCP)
- create test Java client applications which can run on a desktop or the System i
- create a data queue demonstration Eclipse RCP client to work with the demo server
- repeat this for message queues
- define an iSeries application, create a server for it and a test System i client
All this needs to be done before talking about Eclipse RCP clients for an iSeries application.

There will be something in this series for most SystemINetwork readers. This won't be simply hypothetical -- demos, examples and applications will actually work and source will be posted on CVSDude.

By the way, does anyone have an example application they can donate?

A mission of this blog is to explore aspects of building Eclipse RCP clients for a System i application. The foundation has to be in place before exploring how to build an RCP client. Before we can consider a desktop Java client which works with a System i application via queues ...
- the application has to be enabled to be served by non System i clients, any client -- not just RCP
- understand the use of Java toolbox classes for data queues and message queues beyond the the introductory documentation

To accomplish this the blog will follow this path:

• Propose an implementation of the Model or server portion of the Model-View-Controller design pattern using data and messages queues to communicate with the client. Chapter 5 of the IBM Redbook, "Who Knew You Could Do That with RPG IV? A Sorcerer's Guide to System Access and More" covers data queues and message queues. Data queues get application data between the client and server, message queues communicate problems back to the client. See the Redbook references if you want to know more.


• Develop a simple RPG "server" to simulate data queue communication between the server and its clients


• Develop an even simplier CL client to test the server, again using data queues


• Take a look at data queues in Java beyond the examples presented in the JT Open documentation.


• Write Java applications (programs with a main() method started by java.exe) to demonstrate data queue techniques which interact with the dummy server running on the System i. This does not envolve Eclipse. These applications can run on the desk top or on the System i


• Develop an example Eclipse RCP client (view-controller) that communicates with the a demonstration System i server (model) using data queues.


• Repeat the test environment and exloration process for message queues.


• Develop an example Eclipse RCP client (view-controller) that communicates with the demonstration System i server (model) using message queues and message files.


• Implement the model portion of the MVC design pattern for a System i application

All the above needs to be in place before developing Eclipse RCP clients which implement the view-controller portion of the MVC design pattern on the desktop.

Notice that the actual System i application isn't encountered until well into the process, Implementing the model portion of MVC... step. I hope to find a System i application to use in this blog. If nothing turns up then we will use a hypothetical CUSTOMER target application and implement only the portions necessary on the System i.

Posted by Bill Blalock on February 25, 2007 at 5:00 PM | Comments (0)