When does Grails assign an ID to an object?

Question

A Grails 2.3.4 application is connecting to an Oracle database using the following domain class:

class Person {

    String name

    static mapping = {
        id column: "PERSON_ID", generator: "sequence", params: [sequence: 'person_seq']
    }
}

The PersonController makes a call to a method in PersonService and it makes a call to UtilService. The method in UtilService being called has some logic based on wether this Person object is new:

if (personInstance.id == null) { ... }

What I have found is that the id property of personInstance (which is passed through the method calls described above) is assigned when the UtilService is called.

The controller action calling PersonService is @Transactional, and the services do not have any transaction configuration.

So, a couple of questions:

• When is id value assigned by GORM (I assumed at insert but that seems wrong)?
• Is there a better way of checking if the object is new (isAttached() returns true so that's not good for me)?

EDIT: save() has not been called on the personInstance when UtilService does the id check.

Answer 1

Turns out, I had a findBy which was flushing the session:

utilService.someMethod(Person.findByUsername(username))

It was at this point that the id was populated.

Got around it by using withNewTransaction:

def personInstance = Person.withNewSession { Person.findByUsername(username) }
utilService.someMethod(personInstance)

Which now leads me onto the next question...