About sorting FilterBuilder's drop-down values list

[d.cavestro]

I have a FilterBuilder showing a SelectItem for a certain field, but I've not yet found a clean way to sort the SelectItem values.

Let me explain:
My FilterBuilder uses a datasource defined as follows

...
final DataSourceIntegerField optionField = new DataSourceIntegerField ("option", "OPTION");
//NEEDED to let the filter builder show a drop-down list
final SelectItem optionsItem = new SelectItem ();
optionsItem.setName (optionField.getName ());
optionsItem.setOptionDataSource (getOptionDataSource ());
optionsItem.setValueField ("id");
optionsItem.setDisplayField ("name");
//USELESS
optionsItem.setSortField ("name");
optionField.setEditorType (optionsItem);

mainDataSource.addField (optionField);
...

as depicted in http://forums.smartclient.com/showthread.php?t=13775.
If I use the SelectItem in a form I can simply call setSortField on it and it works. But calling this method on a SelectItem used as editorType on the field seems not enough...

Moreover I noticed that if I use the form then the FilterBuilder works fine!?!
Could you please give me some explanations?

I'm attaching a simple test case.

At client side I'm using
SmartClient Version: SC_SNAPSHOT-2010-11-03/LGPL Development Only (built 2010-11-03)
GWT 2.0.4
Firefox 3.6.12


Kind regards
Davide

UPDATE: Obviously, adding a DynamicForm with the SelectItem is not a viable workaround (besides being an ugly solution) since if the form is not visible the FilterBuilder drop-down remains unsorted...

[dencel]

You can use a simple solution like this:

public class SortedDatasource extends DataSource{
		
	public SortedDatasource(DataSource parent) {
		DataSourceField[] unsortedFields = parent.getFields();
		List<DataSourceField> sortedFields = Arrays.asList(unsortedFields);
		Collections.sort(sortedFields, new Comparator<DataSourceField>() {
			@Override
			public int compare(DataSourceField dsf1, DataSourceField dsf2) {
				String dsf1Title = dsf1.getTitle();
				String dsf2Title = dsf2.getTitle();
				
				return dsf1Title.compareTo(dsf2Title);
			}
		});
		for(DataSourceField dsf:sortedFields){
			addField(dsf);
		}
	}
}

and use new SortedDatasource(delegate) on the filterbuilder.