xs:choice generates DataRecord[Any]

[Alexandru Nedelcu]

Hello,

I have the following type described in the xsd:

    <xs:complexType name="AccountIdentification4Choice">
        <xs:choice>
            <xs:element name="IBAN" type="IBAN2007Identifier"/>
            <xs:element name="Othr" type="GenericAccountIdentification1"/>
        </xs:choice>
    </xs:complexType>

This is clearly a union type. But the type generated is:

case class AccountIdentification4Choice(
  accountidentification4choiceoption: scalaxb.DataRecord[Any]
)

I would have expected to see something like:

sealed trait AccountIdentification4Choice

object AccountIdentification4Choice {
  case class IBAN(value: IBAN2007Identifier) extends AccountIdentification4Choice
  case class Othr(value: GenericAccountIdentification1) extends AccountIdentification4Choice
}

Any way to prevent the use of that DataRecord[Any]?

[eugene yokota]

I'll copy this here for the record:

https://twitter.com/eed3si9n/status/1339183897498804225

apparently I blogged about it ten years ago
https://scalaxb.org/narrower-choice

https://twitter.com/alexelcu/status/1339187282637631490

Thanks, haven't seen that.

I wonder why you found it necessary to look for a super-type (e.g. Addressable) instead of wrapping that thing in a union type. The natural representation for the choice in that article would be something like:
https://gist.github.com/alexandru/c74f15070dba2dcb4a23977633bd8815

[eugene yokota]

I think it's good to reexamine earlier design decisions. If I first try to remember my thinking back then, the theme that I kept coming back to is what types represent with regard to data binding some XML document like:

<address>
  <name>John</name>
</address>

If we used case class:

case class Address(name: String)

then, the type String represent an xsd:type, the field name: String represent an xsd:element. Or to put another way, String represents what is in between the angle brackets <name> ... </name>.

If so, what does the case class Address represent? It also represent what is in between <address> ... </address>, and thus case class alone is not enough information to represent the whole of the XML document. It needs to be a field:

address: Address

this field is what DataRecord[A] represents. I almost want a union of literal-and-a-type pairs like:

("groundShipping".type, Address)
  | ("twoDayShipping".type, Address)
  | ("oneDayShipping".type, Address)
  | ("internalShipping".type, InternalAddress)