Visit module and entity

Our domain model now consists of the PetOwner and Pet entities (along with the PetSpecies enum). In this section we’ll add in the Visit entity:

Also, note that the Visit entity is in its own module. We’ll look at the important topic of modularity in later exercises.

Ex 5.1: The visits module

In this exercise we’ll just create an empty visits module.

Solution

git checkout tags/05-01-visit-module
mvn clean install
mvn -pl spring-boot:run

Tasks

Just check out the tag above and inspect the changes:

A new petclinic-module-visits maven module has been created
its pom.xml declares a dependency on the petclinic-module-pets maven module
the top-level pom.xml declares the new Maven module and references it

the VisitsModule class is a Spring @Configuration bean that resides in the root of the visits module, and declares an app dependency on the pets module that mirrors the maven dependency:

VisitsModule.java

@Configuration
@ComponentScan
@Import(PetsModule.class)
@EnableJpaRepositories
@EntityScan(basePackageClasses = {VisitsModule.class})
public class VisitsModule implements ModuleWithFixtures {

    @Override
    public FixtureScript getTeardownFixture() {
        return new FixtureScript() {
            @Override
            protected void execute(ExecutionContext executionContext) {
                // nothing to do
            }
        };
    }
}

the webapp Maven module now depends on the new visits maven module, and the top-level ApplicationModule Spring @Configuration bean now depends upon VisitsModule rather than PetsModule

It still depends upon PetsModule, but now as a transitive dependency.

Ex 5.2: Visit entity’s key properties

Now we have a visits module, we can now add in the Visit entity. We’ll start just with the key properties.

git checkout tags/05-02-visit-entity-key-properties
mvn clean install
mvn -pl spring-boot:run

Tasks

add a Visit entity, declaring the pet and visitedAt key properties:

Visit.java

@Entity
@Table(
    schema="visits",        (1)
    name = "Visit",
    uniqueConstraints = {
        @UniqueConstraint(name = "Visit__pet_visitAt__UNQ", columnNames = {"owner_id", "name"})
    }
)
@EntityListeners(CausewayEntityListener.class)
@Named("visits.Visit")
@DomainObject(entityChangePublishing = Publishing.ENABLED)
@DomainObjectLayout()
@NoArgsConstructor(access = AccessLevel.PUBLIC)
@XmlJavaTypeAdapter(PersistentEntityAdapter.class)
@ToString(onlyExplicitlyIncluded = true)
public class Visit implements Comparable<Visit> {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id", nullable = false)
    @Getter @Setter
    @PropertyLayout(fieldSetId = "metadata", sequence = "1")
    private Long id;

    @Version
    @Column(name = "version", nullable = false)
    @PropertyLayout(fieldSetId = "metadata", sequence = "999")
    @Getter @Setter
    private long version;


    Visit(Pet pet, LocalDateTime visitAt) {
        this.pet = pet;
        this.visitAt = visitAt;
    }


    public String title() {
        return titleService.titleOf(getPet()) + " @ " + getVisitAt().format(DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm"));
    }

    @ManyToOne(optional = false)
    @JoinColumn(name = "pet_id")
    @PropertyLayout(fieldSetId = "name", sequence = "1")
    @Getter @Setter
    private Pet pet;

    @Column(name = "visitAt", nullable = false)
    @Getter @Setter
    @PropertyLayout(fieldSetId = "name", sequence = "2")
    private LocalDateTime visitAt;


    private final static Comparator<Visit> comparator =
            Comparator.comparing(Visit::getPet).thenComparing(Visit::getVisitAt);

    @Override
    public int compareTo(final Visit other) {
        return comparator.compare(this, other);
    }

    @Inject @Transient TitleService titleService;
}

1	in the "visits" schema. Modules are vertical, cutting through the layers. Therefore the database schemas echo the Spring `@Configuration`s and maven modules. Run the application, and confirm that the table is created correctly using Prototyping H2 Console.

Ex 5.3: "Book Visit" action

In addition to the key properties, the Visit has one further mandatory property, reason. This is required to be specified when a Visit is created ("what is the purpose of this visit?")

In this exercise we’ll add that additional property and use a mixin to allow Visits to be created.

git checkout tags/05-03-schedule-visit-action
mvn clean install
mvn -pl spring-boot:run

Tasks

add the @Reason meta-annotation

Reason.java

@Property(maxLength = Reason.MAX_LEN)
@PropertyLayout(named = "Reason")
@Parameter(maxLength = Reason.MAX_LEN)
@ParameterLayout(named = "Reason")
@Target({ ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.ANNOTATION_TYPE })
@Retention(RetentionPolicy.RUNTIME)
public @interface Reason {

    int MAX_LEN = 255;
}

add the reason mandatory property:

Visit.java

@Reason
@Column(name = "reason", length = FirstName.MAX_LEN, nullable = false)
@Getter @Setter
@PropertyLayout(fieldSetId = "details", sequence = "1")
private String reason;

update constructor (as this is a mandatory property)

Visit.java

Visit(Pet pet, LocalDateTime visitAt, String reason) {
    this.pet = pet;
    this.visitAt = visitAt;
    this.reason = reason;
}

create a "visits" mixin collection as a mixin of Pet, so we can see the Visits that have been booked:

Pet_visits.java

@Collection
@CollectionLayout(defaultView = "table")
@RequiredArgsConstructor
public class Pet_visits {

    private final Pet pet;

    public List<Visit> coll() {
        return visitRepository.findByPetOrderByVisitAtDesc(pet);
    }

    @Inject VisitRepository visitRepository;
}

create a "bookVisit" mixin action (in the visits module), as a mixin of Pet.

We can use ClockService to ensure that the date/time specified is in the future, and to set a default date/time for "tomorrow"

Pet_bookVisit.java

@Action(
        semantics = SemanticsOf.IDEMPOTENT,
        commandPublishing = Publishing.ENABLED,
        executionPublishing = Publishing.ENABLED
)
@ActionLayout(associateWith = "visits", sequence = "1")
@RequiredArgsConstructor
public class Pet_bookVisit {

    private final Pet pet;

    public Visit act(
            LocalDateTime visitAt,
            @Reason final String reason
            ) {
        return repositoryService.persist(new Visit(pet, visitAt, reason));
    }
    public String validate0Act(LocalDateTime visitAt) {
        return clockService.getClock().nowAsLocalDateTime().isBefore(visitAt)   (1)
                ? null
                : "Must be in the future";
    }
    public LocalDateTime default0Act() {
        return clockService.getClock().nowAsLocalDateTime()                     (2)
                .toLocalDate()
                .plusDays(1)
                .atTime(LocalTime.of(9, 0));
    }

    @Inject ClockService clockService;
    @Inject RepositoryService repositoryService;
}

1	ensures that the date/time specified is in the future.
2	defaults to 9am tomorrow morning.

Also add in the UI files:

create a Visit.layout.xml layout file.
add a Visit.png file
add a Pet#visits.columnOrder.txt file

to define which properties of Visit are visible as columns in Pet's visits collection.

Optional exercises

If you decide to do this optional exercise, make the changes on a git branch so that you can resume with the main flow of exercises later.

Download a separate Visit-NN.png for each of the days of the month (1 to 31), and then use iconName() to show a more useful icon based on the visitAt date.
Use choices to provide a set of available date/times, in 15 minutes slots, say.
Refine the list of slots to filter out any visits that already exist

Assume that visits take 15 minutes, and that only on visit can happen at a time.