BP Server assigns default values to undefined dataslots of a process instance. Depending on the dataslot type, as declared in the BP Server process, the default value is:
INT64 dataslot: -1
INTEGER dataslot: -1.0
LOGICAL dataslot: false
CHARACTER dataslot: "<NULL>"
When writing rules that process dataslots that can be undefined, you are expected to know the original type of the dataslot in BP Server, so that the expected form of an undefined value is tested properly. Remember that because event attributes are untyped, these default values are rendered as string values in a rule; that is, the string "-1" for an event attribute that represents an undefined long dataslot, or the string "false" for an event attribute that represents an undefined LOGICAL dataslot. Default type conversions are done automatically if the context allows. For example, the condition: (EVT_1.mylongDS = -1) is true if the dataslot "mylongDS" was undefined in BP Server. In other cases, explicit use of type conversion functions is recommended.
For more information about process instance events, workstep events and work item events, see the Application Developer's Guide.
INT64 dataslot: -1