<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:DNS="https://www.densomex.com:4443/Addenda/DNS"
    targetNamespace="https://www.densomex.com:4443/Addenda/DNS"
    elementFormDefault="qualified"
    attributeFormDefault="unqualified">
    <!-- Tipo Invoice Reference -->
    <xs:simpleType name="InvoiceReferenceType">
        <xs:restriction base="xs:string">
            <xs:minLength value="6"/>
            <xs:maxLength value="20"/>
        </xs:restriction>
    </xs:simpleType>
     
    <!-- Elemento raíz Invoice -->
    <xs:element name="Invoice">
        <xs:complexType>
            <!-- Reference obligatorio -->
            <!-- Este dato se mandara solamente cuando sea proveedor Nacional  -->
            <xs:attribute name="Reference" 
                          type="DNS:InvoiceReferenceType" 
                          use="required"/>
        </xs:complexType>
    </xs:element>
</xs:schema>