ABL provides events you can invoke to execute application-specific code that handles FILL operations on a ProDataSet object or Buffer object, as well as row-level change operations. You can use the
SET-CALLBACK-PROCEDURE( ) method to associate an action with these events.
Event procedures must define a single parameter for the ProDataSet object (DATASET or DATASET-HANDLE) as an INPUT parameter BY-REFERENCE. This allows the event procedure to operate on the ProDataSet object using static ABL to reference its buffers and fields, without the ProDataSet object being physically copied. This also means that because the ProDataSet object is not copied, changes made to the ProDataSet object by the event procedure are made to the same copy used by all procedures.
