xml - XSD date format overriding

Question

I am defining an XSD. I need to define an element which takes date in format yyyymmdd. How can I define a restriction in XSD to only accept this format?

Answer 1

You could always define it as a restricted simple type based on a string, restricted by a regular expression:

<xs:simpleType name="FormattedDateType">
   <xs:restriction base="xs:string">
       <xs:pattern value="d{8}"/>
   </xs:restriction>
</xs:simpleType>

If you want to get really smart, you can tweak the regular expression to be even more of a match for a date (e.g. contains the info that month can only be 01 - 12 and so forth):

<xs:simpleType name="FormattedDateType">
   <xs:restriction base="xs:string">
       <xs:pattern value="d{4}(0[1-9]|1[012])(0[1-9]|[12][0-9]|3[01])"/>
   </xs:restriction>
</xs:simpleType>

Marc