This function will perform some functionality before an ABO Job is created to delete a Directory Object.
More info on ABO Jobs and when this PEI is called:
When the user deletes an Directory Folder, since this action might require a lot of processing time, he will have the choice between deleting the folder now or scheduling an ABO Job to do it later and minimize the impact on the Portal's performance. If he decides to do it now, the OnDeleteDirectoryFolder PEI is called, if he decides to have it done later by a Job, the OnBeforeCreateABOJob and OnAfterCreateABOJob PEIs are called.
String - Error message if the creation of the ABO Job should not continue, empty string or null if it should.
IDirectoryActions Interface | com.plumtree.portalpages.pei Namespace