SearchStreet.java

public class SearchStreet {

    private static final Logger LOGGER = LoggerFactory.getLogger(SearchStreet.class);

    @Inject
    private AddressService addressService;
    @Property
    private String streetName;
    @Property
    private String zipCode;
    @Property
    private String municipalityCode;
    @Property
    private Street street;
    @Property
    private Set<Street> streets;

    Object onSuccess() {
        LOGGER.debug(String.format("Called SearchStreet with following parameters: %s %s %s", streetName, zipCode, municipalityCode));
        Set<Street> streets = new HashSet<Street>();
        if (zipCode != null && !zipCode.equals("")) {
            List<Street> streetsByZip = addressService.getStreetsByZip(zipCode);
            if (streetsByZip != null || !streetsByZip.isEmpty()) {
                streets.addAll(streetsByZip);
            }
        }
        if (municipalityCode != null && !municipalityCode.equals("")) {
            List<Street> streetsByMunicipality = addressService.getStreetsByMunicipality(municipalityCode);
            if (streetsByMunicipality != null || !streetsByMunicipality.isEmpty()) {
                streets.addAll(streetsByMunicipality);
            }
        }
        this.streets = streets;
        return this;
    }

}

SearchStreet.tml

    <t:form>
        <t:label for="streetName"/>:
        <t:textfield t:id="streetName" />
        <br/>
        <t:label for="zipCode"/>:
        <t:textfield t:id="zipCode" validate="regexp"/>
        <br/>
        <t:label for="municipalityCode"/>:
        <t:textfield t:id="municipalityCode" validate="regexp"/>
        <br/>
        <t:submit t:id="search" value="Search"/>

        <br/>
        <t:grid source="streets" row="street">
        </t:grid>
    </t:form>