Chapter 16: Substitution groups¶

Schema

<!--Definitive XML Schema by Priscilla Walmsley (c) 2012 Prentice Hall PTR -->
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:annotation>
    <xsd:documentation>
      This example illustrates substitution groups.
    </xsd:documentation>
  </xsd:annotation>

  <xsd:element name="items" type="ItemsType"/>
  <xsd:complexType name="ItemsType">
    <xsd:sequence>
      <xsd:element ref="product" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:element name="product" type="ProductType"/>
  <xsd:complexType name="ProductType">
    <xsd:sequence>
      <xsd:element name="number" type="xsd:integer"/>
      <xsd:element name="name" type="xsd:string"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:element name="shirt" type="ShirtType"
                substitutionGroup="product"/>
  <xsd:complexType name="ShirtType">
    <xsd:complexContent>
      <xsd:extension base="ProductType">
        <xsd:sequence>
          <xsd:element name="size" type="ShirtSizeType"/>
          <xsd:element name="color" type="ColorType"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

  <xsd:element name="hat" substitutionGroup="product">
  <xsd:complexType>
    <xsd:complexContent>
      <xsd:extension base="ProductType">
        <xsd:sequence>
          <xsd:element name="size" type="HatSizeType"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>
  </xsd:element>

  <xsd:element name="umbrella" substitutionGroup="product"/>

  <xsd:complexType name="ShirtSizeType">
    <xsd:simpleContent>
      <xsd:extension base="xsd:integer">
        <xsd:attribute name="system" type="xsd:token"/>
      </xsd:extension>
    </xsd:simpleContent>
  </xsd:complexType>

  <xsd:complexType name="HatSizeType">
    <xsd:simpleContent>
      <xsd:extension base="xsd:token">
        <xsd:attribute name="system" type="xsd:token"/>
      </xsd:extension>
    </xsd:simpleContent>
  </xsd:complexType>

  <xsd:complexType name="ColorType">
    <xsd:attribute name="value" type="xsd:string"/>
  </xsd:complexType>

</xsd:schema>

XML Document

<items xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:noNamespaceSchemaLocation="chapter16.xsd">
  <product>
    <number>999</number>
    <name>Special Seasonal</name>
  </product>
  <shirt>
    <number>557</number>
    <name>Short-Sleeved Linen Blouse</name>
    <size>10</size>
    <color value="blue"/>
  </shirt>
  <hat>
    <number>563</number>
    <name>Ten-Gallon Hat</name>
    <size>L</size>
  </hat>
  <umbrella>
    <number>443</number>
    <name>Deluxe Golf Umbrella</name>
  </umbrella>
</items>

xsData XML Document

<?xml version='1.0' encoding='UTF-8'?>
<items>
  <umbrella>
    <number>443</number>
    <name>Deluxe Golf Umbrella</name>
  </umbrella>
  <hat>
    <number>563</number>
    <name>Ten-Gallon Hat</name>
    <size>L</size>
  </hat>
  <shirt>
    <number>557</number>
    <name>Short-Sleeved Linen Blouse</name>
    <size>10</size>
    <color value="blue"/>
  </shirt>
  <product>
    <number>999</number>
    <name>Special Seasonal</name>
  </product>
</items>

xsData JSON

{
    "umbrella": [
        {
            "any_element": {
                "qname": null,
                "text": null,
                "tail": null,
                "children": [
                    {
                        "qname": "number",
                        "text": "443",
                        "tail": null,
                        "children": [],
                        "attributes": {}
                    },
                    {
                        "qname": "name",
                        "text": "Deluxe Golf Umbrella",
                        "tail": null,
                        "children": [],
                        "attributes": {}
                    }
                ],
                "attributes": {}
            }
        }
    ],
    "hat": [
        {
            "number": 563,
            "name": "Ten-Gallon Hat",
            "size": {
                "value": "L",
                "system": null
            }
        }
    ],
    "shirt": [
        {
            "number": 557,
            "name": "Short-Sleeved Linen Blouse",
            "size": {
                "value": 10,
                "system": null
            },
            "color": {
                "value": "blue"
            }
        }
    ],
    "product": [
        {
            "number": 999,
            "name": "Special Seasonal"
        }
    ]
}

Samples Source