How to exclude an enumeration value in XML file using XSD?

Question

Is it possible to specify the value of a tag or attribute should not be like some_value ?

I have a strange requirement, where the xsd isn\'t

Answer 1

Use regular expressions to specify a pattern or as in your case what a pattern should not contain.

http://www.w3schools.com/schema/schema_facets.asp

Answer 2

I'm no regex expert, but this simpleType makes everything starting with data_migration invalid.

<xs:simpleType name="notDataMigration">
  <xs:restriction base="xs:string">
    <xs:pattern value="^(?!data_migration).*" />
  </xs:restriction>
</xs:simpleType>

Answer 3

I don't know if you can specifically exclude a value. I'm not sure if this helps, but you can create two separate enumerations and then create the union of the enumerations.

<xsd:simpleType name="IncludedEnumType">
  <xsd:restriction base="xsd:string">
    <xsd:enumeration value="pending" />
    <xsd:enumeration value="in_process" />
    <xsd:enumeration value="failed" />
    <xsd:enumeration value="unknown" />
  </xsd:restriction>
</xsd:simpleType>

<xsd:simpleType name="ExcludedEnumType">
  <xsd:restriction base="xsd:string">
    <xsd:enumeration value="data_migration" />
  </xsd:restriction>
</xsd:simpleType>

<xsd:simpleType name="CombinedEnumType">
  <xsd:union memberTypes="IncludedEnumType ExcludedEnumType" />
</xsd:simpleType>

You would use either IncludedEnumType or CombinedEnumType as necessary. Using the IncludedEnumType would obviously excluded the values in ExcludedEnumType.

This approach uses Solution 2 from this article by IBM.