Code of a ChangePreprocessor implementing a security proxy based security scheme.

UpdateSecurityProxy.java

public class UpdateSecurityProxy implements ChangePreprocessor {

  @Override
  public boolean preprocessObjectChange(IndependentlyPersistableObject object)  
    throws EngineRuntimeException {

    Property department = getDepartment(object);
    if (department != null && department.isDirty()) {
      updateSecurityProxy(object, department.getStringValue() );
      return true;
    }
    return false;
  }

  private void updateSecurityProxy(IndependentlyPersistableObject object,       
                                   String departmentName ) {
    ObjectStore objectStore = ((RepositoryObject) object).getObjectStore();
    CustomObject departmentAccess = getDepartmentAccess(departmentName,objectStore);
    object.getProperties().putValue("DepartmentAccess", departmentAccess);
  }

  private Property getDepartment(IndependentlyPersistableObject object) {       
    Properties properties = object.getProperties();
    if (properties.isPropertyPresent("Department")) {
      return properties.get("Department");
    }
    return null;
  }

  private CustomObject getDepartmentAccess(String department,                    
                                           ObjectStore objectStore) {
    IndependentObjectSet objects = searchDepartmentAccess(department, objectStore);
    if (!objects.isEmpty()) {
      return (CustomObject) objects.iterator().next();
    } else {
      throw new RuntimeException("Department '" + department + "' was not found!");
    }
  }

  private IndependentObjectSet searchDepartmentAccess(String department,        
                                                      ObjectStore objectStore) {
    SearchScope searchScope = new SearchScope(objectStore);
    String queryString = "SELECT This " +
                         "FROM DepartmentAccess " +
                         "WHERE Department = " +
                         "'" + department + "'";
    SearchSQL searchSql = new SearchSQL(queryString);
    IndependentObjectSet objects = searchScope.fetchObjects(searchSql, null, null, null);
     return objects;
  }
}