Programming Guide - Actian

How You Can Use Data Entry Error HandlersThe integer value returned by a data entry error handler determines whetherOpenROAD searches for other error handlers defined by parents. There are twointeger values that error handlers return:EH_RESUMECauses normal execution to be resumed, displaying non-blank messages ina pop-up; the message can be revised by the codeEH_NEXT_HANDLERCauses the search for handlers to be resumed, starting with the parent ofthe executable object in which the current handler was foundIf none of the handlers removes the error condition by resetting the field'svalue, the field triggering the error condition retains input focus and the cursorremains on the error field.If one of the handlers removes an error condition that was detected when thefield attempted to give up input focus, the input focus is changed. Events (suchas SetValue) are generated as if the user had entered valid data.How You Can Customize Error MessagesError handlers that remove an error condition should not returnEH_NEXT_HANDLER.The search for other handlers defined by parent executable objects stops wheneither no handler is found, or the current handler returns EH_RESUME.The top frame (main_control) of the Videos application defines a local errorhandlingprocedure that it establishes as a data entry error handler. Becauseall frames in the application are called from the main_control frame, everyframe in the application calls this handlerproc procedure implicitly wheneverusers type invalid values into entry fields.312 Programming Guide