* @return <code>null</code> to force the page to reload
*/
@Override
public Object fetch() {
if (isBatching()) {
_NSDelegate delegate = null;
if (delegate() != null) {
delegate = new _NSDelegate(WODisplayGroup.Delegate.class, delegate());
if (delegate.respondsTo("displayGroupShouldFetch") && !delegate.booleanPerform("displayGroupShouldFetch", this)) {
return null;
}
}
if (undoManager() != null) {
undoManager().removeAllActionsWithTarget(this);
}
NSNotificationCenter.defaultCenter().postNotification("WODisplayGroupWillFetch", this);
refetch();
if (delegate != null) {
// was initialized above
if (delegate.respondsTo("displayGroupDidFetchObjects")) {
delegate.perform("displayGroupDidFetchObjects", this, _displayedObjects);
}
}
return null;
}
return super.fetch();