making an element optional using xsd -cvc-length-valid ERROR

Question

<xs:element name="CurrencyCode" minOccurs="0">
  <xs:simpleType>
    <xs:restriction base="xs:string">
      <xs:length value="3" />
    </xs:restriction>
  </xs:simpleType>
</xs:element>

But if my value is empty it returns an error

cvc-length-valid: Value '' with length = '0' is not facet-valid with respect to length '3' for type '#AnonType_CurrencyCodeServiceServiceList'.

So how can i deal with it ?

Answer 1

Your schema allows to omitt the CurrencyCode element but if it is present its value must be a string with exactly 3 characters length.

You could weaken your restriction to allow 0-length values by specifying min and max length:

<xs:element name="CurrencyCode" minOccurs="0">
    <xs:simpleType>
        <xs:restriction base="xs:string">
            <xs:minLength value="0" />
            <xs:maxLength value="3" />
        </xs:restriction>
    </xs:simpleType>
</xs:element>

This will however allow values like "EU " which is not a valid currency code.

---

A different approach would be, to specify a list of valid currency code values and include an empty string as a valid code:

<xs:element name="CurrencyCode" minOccurs="0">
    <xs:simpleType>
        <xs:restriction base="xs:string">
            <xs:enumeration value=""/>
            <xs:enumeration value="USD"/>
            <xs:enumeration value="GBP"/>
            <xs:enumeration value="EUR"/>
            <!-- add all currency codes you need -->
        </xs:restriction>
    </xs:simpleType>
</xs:element>