Impossible to start an union with a named type

[Tony Imbault]

Hi everybody,

i am trying to build the followong JSON schema:

[{
     "type": "record",
     "name": "Author",
     "fields": [{
          "name": "name",
          "type": "string"
     },
     {
          "name": "birthday",
          "type": "long"
     }]
},
{
     "type": "record",
     "name": "Book",
     "fields": [{
          "name": "title",
          "type": "string"
     },
     {
          "name": "author",
          "type": ["Author", "string"]
     }]
}]

In my humble opinion this JSON schema is valid.

But it seems that the SchemaBuilder API does not permit to build this schema.
The corresponding code should be something like that:

Schema schema = SchemaBuilder
                     .unionOf()
                     .record("Author")
                     .fields()
                     .name("name").type().stringType().noDefault()
                     .name("birthday").type().longType().noDefault()
                     .endRecord().and()
                     .record("Book")
                     .fields()
                     .name("title").type().stringType().noDefault()
                     .name("author").type().unionOf()
                     .type("Author").and()
                     .stringType().endUnion()
                     .noDefault()
                     .endRecord().endUnion();

But after a call to unionOf() the type(name) method is not available.

Is there any reason for this limitation?

Thank you very much

Tony Imbault