Spring Data Rest and excerpt Projections - spring

Question

I am using the inlineAddress sample of the Spring Data Rest documentation.
/persons return the address inline as expected.
Now I add a projection to the AddressRepository
#RepositoryRestResource(excerptProjection = AddressProjection.class)
Which is as below
#Projection(name = "AddressesProjection", types = Address.class)
public interface AddressProjection {
public String getStreet();
}
This is causing the /persons call to have an address projection as _embedded
{
"_embedded" : {
"persons" : [ {
"firstName" : "dfdf",
"lastName" : "2",
"addresses" : [ {
"street" : "tx",
"state" : "tx",
"country" : "dfd"
} ],
"_embedded" : {
"addresses" : [ {
"street" : "tx",
"_links" : {
"self" : {
"href" : "/api/addresses/1{?projection}",
"templated" : true
}
}
} ]
},
"_links" : {
"self" : {
"href" : " api/persons/1{?projection}",
"templated" : true
},
"addresses" : {
"href" : " /api/persons/1/addresses"
}
}
} ]
}
}
I dont know if this is expected. This behaviour is causing repeated information when I have a oneToMany relation like order/Comments and have projection on both order and comments and when I access order/1/comments I see the order also embedded for each comments.

Answer 1

I have a similar issue with spring-data-rest 2.5.6. So I'd like to add this.
If :
an A entity has a #OneToMany relationship to a B entity
the B entity's repository #RepositoryRestResource contains an excerptProjection
Then spring-data-rest will embed the B entity's list in any A entity (in _embedded).
If there is no excerptProjection, the list won't be embedded.
I'd like to be able to choose what I want to be embedded, but at moment, I found no solution to do so.

Answer 2

For anybody that is looking for the answer to this issue, I actually did find a solution.
Based on the example in Spring-RestBucks you will need to have a custom RepresentationModelProcessor on A entity.
Also consider the official Spring HATEOAS Documentation on RepresentationModelProcessor.
Applying to the above example, you would do:
public class PersonRepresentationProcessor implements RepresentationModelProcessor<EntityModel<Person>> {
private final EntityLinks entityLinks;
#Override
public EntityModel<Person> process(EntityModel<Person> personModel) {
// create new EntityModel without the embedded collection
TypedEntityLinks<Person> typedPersonLink = entityLinks.forType(Person::getId);
EntityModel<Person> newPerson = new EntityModel<>(personModel.getContent(),
personModel.getLinks());
// add more links or other modifications
return newPerson;
}
}