I have two entities with the same properties (one ...

# announcements

[Philipp Mayer]

I have two entities with the same properties (one is basically a DTO) an I want to create the DTO from the Entity.
Something comparable to:

class EmployeeModel(val id: Long, val firstName: String, val lastName: String)
class Employee(val id: Long, val firstName: String, val lastName: String)

is there a more idiomatic way of creating one object from the other than:

EmployeeModel(employee.id, employee.firstName, employee.lastName)

Thank you!

[Philip Puffinburger]

I typically just add a secondary constructor that takes the second object like…

class EmployeeModel(val id: Long, val firstName: String, val lastName: String) {
    constructor(employee: Employee) : this(employee.id, employee.firstName, employee.lastName)
}

[Philipp Mayer]

Great, exactly what I was looking for. I'm suprised that didn't come up to my mind.
Thank you!

[David Eriksson]

I would not add that second constructor as it creates a hard coupling between the classes. Will get back with my own suggestion soon.

[Philipp Mayer]

If I'm not missing something I think that's not a problem in this scenario since the EmployeeModel is basically just a DTO for HATEOAS.

Besides that it would be nice to see your solution!

[David Eriksson]

val model = with(employee) {
  EmployeeModel(id, firstName, lastName)
}

or

val model = employee.run {
  EmployeeModel(id, firstName, lastName)
}

or as extension function:

fun Employee.toModel()  = EmployeeModel(id, firstName, lastName)
// ...
val model = emplyee.toModel()

[David Eriksson]

(not tested code, at the wrong computer now)

[cucharro]

great suggestions