Kofax DOKuStar Validation - Manual (Page 39)

DOKuStar Validation Programming Manual Page • 35
Events
Concept
Certain objects can get events. You will probably use the events defined for the FieldType and the
DocumentType object, but there are many more objects which have the ability to get events. For example, an
event may be assigned to a single Field (instead of the FieldType ), e.g. to the amount field on the first document.
So you could add code that would be executed if the user changed the amount on the first document, but not, if he
changed the amount on one of the following documents.
This manual will not describe every event for every object, but concentrates on the most important items. To see the
complete list, refer to the reference help file, or use VBA‘s object browser: Open the VBA development studio, press
F2 and select the DOKuStarValidation library.
DOKuStar Validation event handling routines use a special naming scheme:
They all begin with On ... and end with ... ing , ... ed or …ingCanceled . For example, consider the
OnFieldChanging , OnFieldChanged and OnFieldChangingCanceled event. For most events, you
will always have such a group of three events.
Rules:
The ... ing event always comes first and can be aborted by the scripting routine. If the scripting routine wants to
abort the event, it must return False , else True . So, for the OnFieldChanging example, this event means: “The
value of the field is about to be changed. Any Objection?”
When True is returned, you will next get the …ed event, in our case the OnFieldChanged. This event
indicates, that the changing of the field now took place. Contrarily, when False was returned in the …ing you will
next get an …ingCanceled , indicating that the changing of the value was canceled.
Note that when you return False in the ... ing event, all events that might follow will not be fired (except the
Canceled event); especially, you will not get the corresponding ... ed event.
In the example above the OnFieldChanging event was used, since we wanted to abort the changing in some
situations. If the OnFieldChanged event had been used, the old contents could not have been restored.
Consequently, event handling routines for ... ing events are always functions that return a Boolean, while ... ed
routines are always subroutines.
When writing an event handling routine, proceed as follows:
- Define a variable of the appropriate object type:
Dim WithEvents fld As FieldType
- This variable will now appear in the drop down list above the editing window. Select it: