How to get nested ValueObject changes? - javers

Question

I have the following hierarchy of classes:
class Incident {// Id => Entity
#Id
String id
List<Participant> participants
List<RealEstateProperty> realEstateProperties
}
where
class Participant {// No id => by javers terms - ValueObject
EnclosedContact contact
}
class EnclosedContact {// No id => by javers terms - ValueObject
String name
}
class RealEstateProperty {// No id => by javers terms - ValueObject
List<CadastralSection> cadastralSections
}
class CadastralSection {// No id => by javers terms - ValueObject
String sectionId
}
I have written the following test (in groovy):
def "Querying Javers Repository for participants changes works correctly"() {
given:
(1..3).each {
javers.commit("author", new Incident(
id: it,
participants: [
new Participant(contact: new EnclosedContact(id: 20 + it))
]
))
}
when:
def snapshots = javers.findSnapshots(QueryBuilder.byValueObjectId(1, Incident.class, "contact").build())
then:
assert snapshots.size() == 1
}
The result of this test is:
JaversException: PROPERTY_NOT_FOUND property 'contact' not found in class 'Incident'
Trying to get the changes this way
def snapshots = javers.findSnapshots(QueryBuilder.byValueObjectId(1, Incident.class, "participants/0/contact").build())
returns empty list.
Does Javers support selecting for changes on nested ValueObjects?

Answer 1

in JaVers 1.6.2 there is a basic support for nested ValueObjects queries (undocumented yet). Your query should work for data persisted by this JaVers version. For example:
def "should query for changes on nested ValueObjects stored in a list"(){
given:
def user = new DummyUserDetails(
id:1,
addressList: [new DummyAddress(networkAddress: new DummyNetworkAddress(address: "a"))])
javers.commit("author", user)
user.addressList[0].networkAddress.address = "b"
javers.commit("author", user)
when:
def changes = javers.findChanges(QueryBuilder.byValueObjectId(1, DummyUserDetails,
"addressList/0/networkAddress").build())
then:
changes.size() == 1
changes[0].left == "a"
changes[0].right == "b"
}

Answer 2

I created a generic nested object comparator, hope it helps.
https://gist.github.com/hank-cp/3db40faed1dd9f02ababd86c2c9eaf8d
Registers it like this way:
NestedObjectComparator productRootComparator =
new NestedObjectComparator<POProductRoot>() {};
sharedJavers = JaversBuilder.javers()
.registerValue(POProductRoot.class)
.registerCustomComparator(productRootComparator, POProductRoot.class).build();
productRootComparator.setJsonConverter(sharedJavers.getJsonConverter());
Then your will get the changes result in MapChange format.

Answer 3

Since JaVers 2.1, there is a new filter for this type of queries - child-value-objects-filter