jira gadget development, filterPicker for username and groups

how can I create a filterPicker for username and g开发者_高级运维roups? Should be somenthing like for projects, with projectOrFilterPicker right? And is it possible to make a select list with dynamic data in UserPref? for example a list of issues type present on a Jira project

Using a Dynamic Select list with all users in Jira. This code retrieve user list present in Jira and then call createJSON to return data and make the select:

@GET
    @Path ("userlist")
    public Response getUserList() {
        new UserManager();
            com.opensymphony.user.UserManager u = UserManager.getInstance();
        EventPublisher e = null;
        DefaultUserManager users = new DefaultUserManager(u, e);
        Collection<User> listOfUsers = users.getAllUsers();
        return Response.ok(createJSON(listOfUsers).toString()).cacheControl(NO_CACHE).build();
    }