Using RDMI to Trigger External Actions
You can use RDMI to perform an action outside the USoft application whenever a certain condition applies to the application data. For instance, you can send a welcome mail each time a new person record is added to a table.
If you INVOKE from a constraint to trigger an external action, the purpose is to perform an action outside the USoft application when certain conditions apply. The purpose is not to check whether a restrictive rule is being violated.
If the component method does NOT return a value, you can use the standard protocol.
If the component method returns a value, it must be written in such a way that it returns "0" if the action is performed normally, "1" if for some reason the action could not be performed, and "-1" if a fatal error occurred.
In this case, you must use the query protocol.