Grails: Custom validator based on a previous value of the field

Question

I am trying to create a custom validator for variable \'amount\' in my domain class, such that the new value should be greater than previous by 0.50.

For example, l

Answer 1

Thx Victor Sergienko, but I do a little modification on your code

class Bid { 
  Double amount 
  ...
  static constraints = { amount(validator: { double a, Bid b -> 
    Bid tempBid = Bid.get(b.id)
    def oldValue = tempBid.getPersistentValue('amount')
    a > oldValue + 0.5 ? true : "Amount $a should be at least ${oldValue  + 0.5}" }) 
  }
}

The difference is at this line :

Bid tempBid = Bid.get(b.id)
def oldValue = tempBid.getPersistentValue('amount')

I don't why b.getPersistentValue('amount') is always return null value, my grails version is 2.4.3

Answer 2

You can try reading domainEntity.getPersistentValue('amount').

EDIT: ... in custom validator, like:

class Bid { 
  Double amount 
  ...
  static constraints = { amount(validator: { double a, Bid b -> 
    def oldValue = b.getPersistentValue('amount')
    a > oldValue + 0.5 ? true : "Amount $a should be at least ${oldValue  + 0.5}" }) 
  }
}