ListView Add/Remove via AJAX...

[James Carman]

It has been a while since I've used Wicket and man, I really forgot how
much I love this framework! It may be that I'm rusty, but I've searched
quite a bit and tried all the suggestions I've found, but I can't seem to
make add/remove via AJAX work for a ListView while preserving the input
data. I am using Wicket 8.0.0-M9. Here's what I've done so far:

correctChoiceGroup = new CheckGroup<>("correctChoices",
Model.ofSet(Sets.newHashSet()));
correctChoiceGroup.setRequired(true);
correctChoiceGroup.setOutputMarkupId(true);
correctChoiceGroup.setRenderBodyOnly(false);

final IModel<List<String>> choicesModel = Model.ofList(new LinkedList<>());
choicesView = new ListView<String>("choices", choicesModel) {
    @Override
    protected void populateItem(ListItem<String> item) {
        final int index = item.getIndex();

        item.add(new TextField<>("field", item.getModel()));
        item.add(new Check<>("check", Model.of(index)));

        final AjaxSubmitLink deleteLink = new AjaxSubmitLink("deleteButton") {
            @Override
            @SuppressWarnings("unchecked")
            protected void onSubmit(AjaxRequestTarget target) {
                final ListView listView = findParent(ListView.class);
                listView.getModelObject().remove(index);
                listView.removeAll();
                target.add(correctChoiceGroup);
            }
        };
        deleteLink.setDefaultFormProcessing(false);
        item.add(deleteLink);
    }
}.setReuseItems(true);


correctChoiceGroup.add(choicesView);

add(new AjaxSubmitLink("addButton") {
    @Override
    protected void onSubmit(AjaxRequestTarget target) {
        choicesView.getModelObject().add("");
        choicesView.removeAll();
        target.add(correctChoiceGroup);
    }
}.setDefaultFormProcessing(false));

add(correctChoiceGroup);


When I click on the delete link (I have a similarly-implemented "add" link
outside of the ListView), all of the input data goes away, since I am
losing the original items from the removeAll() call.  Now, I am doing the
removeAll() to force Wicket to realize that I've changed the underlying
list, otherwise, the original items are reused and the it always looks like
the last item is removed.  I'm sure I'm just rusty, but I am banging my
head on this one.

Thanks,

James