1.4.4 Where is RDML Used?
RDML is used for many different purposes in the LANSA development environment. You can use RDML for the following:
Application Programs (LANSA functions) and Components
This is the most common use of RDML. Developers use RDML to build the application logic within their business programs. Components created with Visual LANSA will also use RDMLX commands, which are specific to component development.
Trigger Functions
RDML can be used to define database trigger programs so that they can be ported with an application. If a trigger program is coded in a 3GL (such as RPG on the IBM i), it would have to be rewritten (recoded as C), when the application moves to a new database.
Called Validation Functions
Complex validation rules in the LANSA Repository can be coded using RDML.
Built-In Functions
RDML can be used to create specialized Built-In Functions to perform a specific repeated operation.
Stored Procedures
RDML can be used to define stored procedures so that they can be ported with an application. If a stored procedure is coded in a 3GL, it may have to be rewritten when the application moves to a new database.
System Variables
System variables are special variables which can be accessed by LANSA functions. For example, a date, time or company name can be a system variable. RDML can be used to derive the values of these variables.
RDML can execute on the client or server. It is a high-level, platform independent definition of your application logic. A platform independent development language is critical to enable deployment of a repository on more than one platform.