How do I create a transient variable in a Grails Domain Class?

Question

How do I set up a variable within a domain class that is not persistent. I want to be able to write and read to that variable, but I don't want it to be a part of the table.

The way to do this in rails is by setting up a variable with attr_accessor. Is this possible in Grails? Does anyone know how to do this?

Thanks!

Bechler

Answer 1

Just add the names of all the transient variables to the transients list, e.g.

class MyDomain {

  static transients = ['nonPersistent', 'nonPersistent2']

  Integer nonPersistent
  Integer nonPersistent2

  Integer persistent
  Integer persistent2      
}

Electrophorus

Answer 2

Defines a list of property names that should not be persisted to the database. This is often useful if you have read-only accessor methods ("getters") that are helper methods but get confused as being persistence-related.

Examples

class Author {
   String name
   String getUpperCaseName() { name.toUpperCase() }
   static transients = ['upperCaseName']
}

Folkways

Source: docs.grails.org/3.1.1/ref/Domain%20Classes/transients.html – Darendaresay

Answer 3

Here I have created transient variable in domain class-

class Application {
    dataType domainFields  //define datatypes
    static transients = [ 'name']

    String  getName() {
        return 'grails App'
    }
}

Directed