Just like 3.4 Functions, OSWorkflow allows for validators in three different forms: Java-based, BeanShell, and BSF. Java-based validators must implement the com.opensymphony.workflow.Validator interface (or in the case of remote-ejb's, the com.opensymphony.workflow.ValidatorRemote interface). With Java-based validators, throwing an InvalidInputException is all that is needed to mark an input as invalid and stop the workflow action from occuring.
But in BeanShell and BSF, things are a little different, since exceptions thrown in the scripts can't propogate out to the Java runtime environment. To get around this, any value returned in a BeanShell or BSF script will be used as the error message(s). The logic is as follows:
- If the value returned is an InvalidInputException object, that object is immediately thrown to the client
- If the value returned is a Map, that Map is used for the error/errorMessage pairs in the InvalidInputException
- If the value returned is a String[], the even numbers are used as keys, and the odd numbers are used as values to construct a Map that can then be used in the above case.
- Otherwise, the value is converted to a String and added as a generic error message.
