AutoComplete not working in Apache ISIS Action

Question

I have following method:

@Action(semantics = SemanticsOf.SAFE)
@ActionLayout(named = "Find alphabet Soup by Letter", bookmarking = BookmarkPolicy.AS_ROOT)
@MemberOrder(name = "Menu soups", sequence = "7")
public List<SomeObject> findByLetter(@ParameterLayout(named = "letter") final String letter) {
    return container.allMatches(new QueryDefault<SoupObject>(SoupObject.class, "findSoupQuery", "letter", letter)); 
}

I want that the Input-field for the parameter letter is a dropdown-list with autoCompletion. So I added the autoComplete function:

public Collection<String> autoComplete0FindByLetter(@MinLength(3) String search) {
    List<String> ret = new ArrayList<String>();     
    SoupFinder soupFinder = new SoupFinder();
    List<SoupObject> soups = soupFinder.findByLetter(search);
    for (SoupObject tmpSoup : soups) {
        ret.add(tmpSoup.getName(());
    }

    return ret;
}

So my problem is now: When I use the function findByLetter in the Wicked UI there is no dropdown field for the parameter letter. Why is there no dropdown field respectively why does the autoComplete function not work. Did I forget something?

Thanks for your answers.

Answer 1

Autocomplete only works with entities/view models, not with values. Which kind-of makes sense: the point of autoComplete is to do a lookup of existing entities. For strings, you can use choices, but not autoComplete.

I'm not sure if this is properly documented ... until I looked into it, I too thought that your code looked correct.

The closest you can get to the behaviour you are after is to use a very simple view model as a wrapper around the string, eg:

@ViewModel 
public class Choice {
    @Getter @Setter
    private String value;
}

and return a list of those.