To achieve calling this event for the specific variable, it is necessary to
enable the calling explicitly in the variable (see the "
ExtWriteAction > Data extension ExtWriteAction > Event "onItemAfterWrite"" configurator). There it is also defined if the event is triggered after each writing or after each change of the value.
If the triggering is enabled for each variable and writing into (the change of) all variables occurs at a time, then the event is triggered
for each variable separately!
The The usage of this event is appropriate, for example, to inform and test the value for alarm purposes or for special actions that have to occur if the variable changes.
Caution: The event is triggered only if
the real writing is performed (e.g.
object.Item(0).Value=3) into the variable - let's mark it
A. But if the
data binding (during the reading) to another variable
B (in another object) is defined in the
A variable and it is written into the
B variable, then the
A variable doesn't know about the change and
thus the event is not triggered (the
A variable does know about the change only when it is read by someone - data binding is then "performed" - but the the event is not triggered again !).