*/
public IPropertyDescriptor[] getPropertyDescriptors() {
if (_descriptors == null) {
final List result = new ArrayList();
final ITagElementResolver tagregResolver = IStructuredDocumentContextResolverFactory2.INSTANCE
.getResolver(_context, ITagElementResolver.class);
if (tagregResolver != null) { //relies on getTagEntity() having been called to have setup the _element
final ITagElement tag = tagregResolver.getTagElement(_element);
if (tag != null) {
for (final ITagAttribute attr : tag.getAttributes().values()) {
final IPropertyDescriptor pd = getAttrPropertyDescriptor(attr
.getName());
if (pd != null)