Question

how to save class extend in grails?
example i have class user and administrator

class User {
    String name
    String password
}

class Administrator extends User {
    String authoritySelected
}

example in class User i have save “user1”,
and then i want to change user1 from class user to class administrator and update authoritySelected

def update(){
    def user1 = User.get("user1")
    user1.authoritySelected
    user1.save(flush:true)
}

and get error :

No such property: authoritySelected for class:User

so, how to save authoritySelected in class User and change that to class Administrator? thanks.

Answer 1

When you say “and then i want to change user1 from class user to class administrator”, what exactly are you trying to do?

You are trying to access a property of an object that doesn’t exist in that object. Downcasting simply doesn’t work like that. You should instantiate an object of type Administrator in order to save one of its properties after.