2 3 5 RDML and RDMLX Programs

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2.3.5 RDML and RDMLX Programs

RDML Commands that cannot be used in Visual LANSA

When you are writing event-driven programs, the majority of the commands you will use are RDML commands. However, there are a number of commands, called RDMLX commands, which are required for the event-driven programming method.

The RDMLX commands are used to invoke methods, and to handle events and properties. These are all high level 4GL commands which shield you from many of the complexities typical of object-oriented programming. Some of these RDMLX commands are:

RDMLX Only	Description
BEGIN_COM and END_COM	Starts and ends a component definition, usually a form. Inserted automatically.
DEFINE_COM	Defines a component inside another one. Inserted automatically.
EVTROUTINE	Defines a routine for an event. Inserted automatically.
INVOKE	Invokes a method.
SET	Sets a property.
DEFINE_EVT	Creates a user-defined event.
SIGNAL	Triggers a user-defined event.
DEFINE_MAP	Creates input and output parameters.
DEFINE_PTY	Creates a user-defined property.
MTHROUTINE	Creates a user-defined method.
PTYROUTINE	Creates a user-defined property.

The BEGIN_COM, END_COM, DEFINE_COM and EVTROUTINE are automatically inserted by the Visual LANSA editor when you drag and drop components or click on events, so you will never have to enter them yourself.

SET is one of the few RDMLX commands you will be using frequently:

SET COM(#MyEditBox) TEXT('HELLO!')

This command sets the Text property of MyEditBox to 'HELLO!'

RDML Commands that cannot be used in Visual LANSA

Because of the difference in nature between the existing procedural LANSA programs and the event-driven programs there are some RDML commands that cannot be used in Visual LANSA:

RDML Only	Description
DISPLAY, REQUEST, POP_UP	In Visual LANSA you design the interface graphically.
SET_MODE, IF_MODE	Modes are not used because actions can be accomplished directly.
IF_KEY	These involve DISPLAY / REQUEST / POP_UP activities.
MENU	Procedural transfer of control activities.
TRANSFER	Procedural transfer of control activities. This command can be used with WAMs.
DEF_LIST	For browse lists. Working lists may be defined. In Visual LANSA you use list-type components such as list views, grids, and tree views instead.
All Reporting	Reports cannot be produced in RDMLX. Code reporting logic in RDML functions and call them from RDMLX components.
RENAME	Not supported because its use may conflict with class usage rename activities.

Also See

2.1 Introduction to Components and Desktop Applications

RDML Commands in the Technical Reference Guide, for a list of all RDML & RDMLX commands and where each of them can be used.