12.1 LANSA SAA/CUA Overview
LANSA supports the concepts of SAA (Systems Application Architecture) and the panel design and user interaction concepts prescribed by the CUA (Common User Access) guidelines.
This section is about how the SAA/CUA guidelines and standards are implemented within LANSA, it is not about what the actual SAA/CUA guidelines and standards are. For this information refer to the appropriate IBM supplied manuals, such as Systems Application Architecture: Common User Access Basic Interface Design Guide (SC26-4583).
Before attempting to implement (or not to implement) applications in LANSA that use the prescribed SAA/CUA guidelines consider the following points:
- SAA/CUA is an IBM strategic direction. As such the LANSA product has a strong commitment to the concept. While all existing LANSA features will always be supported for non-SAA/CUA applications, new features that become available may only be accessible from SAA/CUA compliant applications.
Note that this does not mean you have to convert all your existing applications to be SAA/CUA compliant (which usually only means recompiling them anyway), but you will have to eventually set up SAA/CUA parameters for all LANSA partitions being used.
While an SAA/CUA compliant partition will readily run non-SAA/CUA RDML applications, a non-SAA/CUA partition cannot run SAA/CUA compliant RDML applications.
- The LANSA implementation of SAA/CUA described by this appendix adheres to the standards and guidelines laid down in the IBM manual System Application Architecture: Common User Access Basic Interface Design Guide (SC26-4583).
It does not necessarily adhere to the recommendations made in the IBM i document "Defining AS/400 Compatible Displays using Data Description Specifications Newsletter" (GC21-8163) and other IBM i publications.
Some of the reasons for this are:
- LANSA supports action bars, pull-downs and pop up windows.
- LANSA supports number or cursor selection.
- In some areas the recommendations do not conform to the SAA/CUA guidelines. For instance, messages should appear above the function key area, not below it.
- The use of SAA/CUA standards requires a firm commitment at the corporate level.
- The full use of SAA/CUA guidelines may meet resistance from some EDP practitioners, in particular those that have worked on System/38s for a long time. They may feel that in many respects the SAA/CUA guidelines are too restrictive.
- The use of some of the features available within the SAA/CUA guidelines such as action bars, pull-downs, pop up windows and the prompt key may significantly change the way application systems are designed. Different architectural methods are generally used for SAA/CUA application systems that use these facilities.