Kbase P67050: What is a Developer Event?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
31/10/2005 |
|
Status: Verified
GOAL:
What is a Developer Event?
GOAL:
How are Developer Events implemented in the 4GL?
GOAL:
How to use Developer Events within the Progress 4GL?
FIX:
Event-driven applications make use of event triggers to determine when certain portions of the application should be executed. These events are categorized as Keyboard events, Mouse events, High Level Widget events, Direct
Manipulation events, or Developer events. Developer events are distinct from the other types in that they are completely "soft" events, meaning that there is no connection between any hardware event necessary. In other words, the event can be triggered by the application itself.
Developer events are given the labels "U1" through "U10".
To cause a Developer event to fire, the 4GL programmer would make use of the APPLY 4GL Statement:
APPLY "U1":U TO <a particular object>. /* or APPLY "U1":U TO THIS-PROCEDURE */
at the point where the processing should occur.
Then, the associated trigger would be defined elsewhere in the procedure:
ON "U1":U OF <a particular object> /* or ON "U1":U ANYWHERE */
DO:
<processing to be done>.
END.
Progress does not generate these events from any other user or system actions.