Extending XSD files

Question

I have an XSD file with an enumerated type. I'd like to create an "extended" XSD file, which adds some additional enumerations, but otherwise behaves just like the main XSD.

For example, the main XSD file contains this:

<xsd:simpleType name="color">
    <xsd:restriction base="xsd:string">
     <xsd:enumeration value="red"></xsd:enumeration>
     <xsd:enumeration value="orange"></xsd:enumeration>
     <xsd:enumeration value="yellow"></xsd:enumeration>
    </xsd:restriction>
</xsd:simpleType>
...
<xsd:element name="myColor" type="color" />

My imaginary extended XSD file would simply add "gold" to the "color" type. The existing "myColor" element would now be able to contain "gold", if it used this XSD instead of the main one.

Is this possible?

Answer 1

How about something like this?

<!-- Your base enumeration -->
<xsd:simpleType name="color">
    <xsd:restriction base="xsd:string">
        <xsd:enumeration value="red"/>
        <xsd:enumeration value="orange"/>
        <xsd:enumeration value="yellow"/>
    </xsd:restriction>
</xsd:simpleType>

<!-- You extended enumeration -->
<xsd:simpleType name="colorEx">
    <xsd:restriction base="xsd:string">
        <xsd:enumeration value="gold"/>
    </xsd:restriction>
</xsd:simpleType>


<xsd:simpleType name="color_union">
     <xsd:union memberTypes="colorEx color"/>
</xsd:simpleType>

<xsd:element name="myColor" type="color_union"/>