Apache Isis - Closing the Architecture/Code Gap

<ixn:interactionDto xmlns:com="http://isis.apache.org/schema/common"
                    xmlns:cmd="http://isis.apache.org/schema/cmd"
                    xmlns:ixn="http://isis.apache.org/schema/ixn">
    <ixn:transactionId>929c2e7a-6318-4f4c-ab7b-96b3632d6731</ixn:transactionId>
    <ixn:execution xsi:type="ixn:actionInvocationDto"
            interactionType="action_invocation"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <ixn:sequence>0</ixn:sequence>
        <ixn:target type="org.estatio.dom.invoice.Invoice" id="1"/>
        <ixn:memberIdentifier>org.estatio.dom.invoice.Invoice#approve()</ixn:memberIdentifier>
        <ixn:parameters/>
        <ixn:returned type="reference" null="false">
            <com:reference type="org.estatio.dom.invoice.Invoice" id="1"/>
        </ixn:returned>
        <ixn:user>estatio-admin</ixn:user>
        <ixn:title>org.estatio.dom.invoice.Invoice:1: approve()</ixn:title>
        <ixn:metrics>
            <ixn:timings>
                <com:startedAt>2016-09-30T13:57:19.825+01:00</com:startedAt>
                <com:completedAt>2016-09-30T13:57:19.832+01:00</com:completedAt>
            </ixn:timings>
            <ixn:objectCounts>
                <ixn:loaded before="4" after="6"/>
                <ixn:dirtied before="0" after="1"/>
            </ixn:objectCounts>
        </ixn:metrics>
    </ixn:execution>
</ixn:interactionDto>

@DomainService
public class ItemCompletedSubscriber {
    @Subscribe
    public void on(ToDoItem.CompletedDomainEvent ev) {
        ToDoItem item = ev.getSource();
        switch(ev.getEventPhase()) {
            case HIDE:
                ev.hide();
                break;
        }
    }
}

@DomainService
public class ItemCompletedSubscriber {
    @Subscribe
    public void on(ToDoItem.CompletedDomainEvent ev) {
        ToDoItem item = ev.getSource();
        switch(ev.getEventPhase()) {
            case DISABLE:
                ev.disable(...);
                break;
        }
    }
}

@DomainService
public class ItemCompletedSubscriber {
    @Subscribe
    public void on(ToDoItem.CompletedDomainEvent ev) {
        ToDoItem item = ev.getSource();
        switch(ev.getEventPhase()) {
            case VALIDATE:
                ev.invalidate(...);
                break;
        }
    }
}

@DomainService
public class ItemCompletedSubscriber {
    @Subscribe
    public void on(ToDoItem.CompletedDomainEvent ev) {
        ToDoItem item = ev.getSource();
        switch(ev.getEventPhase()) {
            case HIDE:
                break;
            case DISABLE:
                break;
            case VALIDATE:
                break;
            case EXECUTING:
                break;
            case EXECUTED:
                break;
        }
    }
}

DemoFixture fs;
Contact contact;

@Before
public void setUp() throws Exception {
    this.fs = new DemoFixture();
    fixtureScripts.runFixtureScript(fs, null);

    this.contact = fs.getContacts().get(0);
}

@Test
public void name_already_in_use_by_contact() throws Exception {
  // given
  final String existingName =
                        fs.getContacts().get(1).getName();
  // expect
  thrown.expect(InvalidException.class);
  thrown.expectMessage("Reason: " +
        "This name is already in use by another contact");
  // when
  wrap(this.contact).edit(existingName, null, null, null);
}