JAXB IDREF and ID usage?

Question

I'm looking to write an XSD which will be used to generate some Java classes via JAXB. I'd like the resulting XML to look like this:

<Appointment>
    <Patient ref="12345">Bob Smith</Patient>
    <Type>Some Appointment Type</Type>
    <Date>2010-02-17</Date>
    ....
</Appointment>

So, given this schema I'm wanting it to generate a class where I can just do something like this:

Patient p = loadPatientFromDB();
Appointment a = new Appointment();
a.setPatient(p);
a.setType("Some Appointment Type");

I think what I am looking to do involves having an element which has an IDREF as an attribute and then a string as the contents of the element.

Can someone give me a hand with some of the XSD?

Thanks!

EDIT

This question could likely also be asked in the following manner.

Can a simpleType have an attribute, or must it be a complexType.

So, can you have

  <element id="foo">bar</element>

or must you have

  <element id="foo"><name>bar</name></element>

Answer 1

I will answer your second question, since it's very clearly asked. No, a simple type cannot have an attribute. What you are looking for is a complex type with simple content:

<xs:complexType name="Person">
    <xs:simpleContent>
        <xs:extension base="xs:string">
           <xs:attribute name="ref" type="xs:IDREF" use="required"/>
        </xs:extension>
    </xs:simpleContent>
</xs:complexType>

Edit: You can now use this type as you intended, assign it to an element called "person" and you can have <person id="foo">A Name</person>.

As for the first question: you still have a bit of extra work if you actually want the IDs resolved. For example, see here.