Question

When I change a domain object, rather than updating the database record, I’d like to archive the old record record and create a new one. I’d like to force GORM to do this automatically.

For example, if I had this domain class:

class User {
    String username
    String email
    Boolean active
}

then I’d like

user.email = email
user.save()

to set the active flag on the user to false, keeping a record of the old email. A new record with the new email address and active = true would be inserted.

Is this a common pattern? Is it easy to do in the domain class so that it happens transparently?

Answer 1

You can use GORM event beforeUpdate into User domain class (see the documentation here and here) with something like the following should work (not tested) :

def beforeUpdate() {
  if (isDirty('email') { //enters only if email was changed. Works only with Grails 1.3.x
  User.withNewSession {
    //Create the new entry
    new User(username:username, email:email).save()
    //Update the old entry with the old email value
    email = getPersistentValue('email')
  }
  }
}