Localized sorting column in a DefaultDatatable

[Olivier Bourgeois <ol...@gmail.com>]

Hi,

I'm trying to implement a simple sortable datatable with Wicket, and I'm
struggling with an issue I can't find a way to solve : how to build a
sortable column when the data to be sorted is also to be translated and
comes from the property files (not from the model directly) ?

I've done this :
- I build an AjaxDefaultDataTable with a sortable dataprovider containing a
country ZoneCode
- this ZoneCode is a key in the property files that provides the display
ZoneLabel

So I thought this kind of code would do the trick :

        List<IColumn<CountryDetails>> columns = new
ArrayList<IColumn<CountryDetails>>();
        columns.add(new PropertyColumn<CountryDetails>(new
Model<String>("Zone"), "zoneLabel", "zoneCode") {

            @Override
            public void populateItem(Item<ICellPopulator<CountryDetails>>
item, String componentId, IModel<CountryDetails> rowModel) {
                CountryDetails detail = rowModel.getObject();
                StringResourceModel srm = new
StringResourceModel(detail.getZoneCode(), item, rowModel);
                item.add(new Label(componentId, srm));
                detail.setZoneLabel(srm.getString());
            }
        });

but all I got is a NullPointerException because a ZoneLabel is empty at some
point in the sort and and a lot of warnings in the logs :

- WARN  org.apache.wicket.Localizer - Tried to retrieve a localized string
for a component that has not yet been added to the page. This can sometimes
lead to an invalid or no localized resource returned. Make sure you are not
calling Component#getString() inside your Component's constructor. Offending
component: [MarkupContainer [Component id = 1]]

Any ideas ?

thanks in advance,
Olivier.