9.4 CUA 1989 Considerations and Commitments

The LANSA implementation of action bars conforms to, and is committed to, the action bar techniques prescribed by the CUA 1989 standard for NPTs (non-programmable terminals).

In CUA terminology, the implementation conforms to the "Text Subset" of the CUA 1989 "Graphical Model".

It is the highest level of CUA implementation achievable on NPTs.

This means that you should carefully consider whether you are also committed to the CUA 1989 standards for the "look" and "feel" of your action bar applications.

The commitment to the "look" is easy to make, but the commitment to the "feel" may involve changes to the way applications are designed and implemented.

These changes will effect your development staff and your end users alike. Both groups may require education about the new standards being used.

Without this commitment, attempts to design and implement an action bar driven system will almost certainly fail to achieve the best possible result.

The key component of the CUA 1989 standards for action bar driven systems is that of the "Object-Action" approach to application design.

Please refer to the IBM supplied CUA manual Common User Access: LANSA Basic Interface Design Guide (SC26-4583) for more details of the Object-Action approach to design. Refer especially to the chapter Action Bar and Pull-Downs and the Appendix Designing an Object-Action Orientated Application.

Unless you are committed to CUA 1989, and are prepared to possibly alter the way you design midrange application systems, you will find that you are generating large amounts of RDML code to "fight against" the natural flow and architecture built into the LANSA implementation of action bars (in support of CUA 1989).

Finally, please note that you do not have to use action bars.

Sometimes the presence of new facilities and techniques makes people feel bound to use them otherwise they are being "old fashioned".

This is not true of action bars.

Some applications may not even be suitable for action bar implementations.

Traditional menu driven applications that conform to the CUA 1989 "Entry Level" model are perfectly valid, and often the best choice, for some types of applications.