Try OpenEdge Now
skip to main content
BPM Events User's Guide
Understanding BPM Events : The XML event : The XML schema definition
 

The XML schema definition

Each message type should have an xsd file. The xsd file describes the elements as well as their type, which is not the case for dtd files. Typing is primordial in rules for detecting errors at compilation time and for guaranteeing fast execution.
Here is the xsd file that the two XML messages above follow:
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:annotation>
      <xsd:documentation xml:lang="en">
          Purchase order schema for Example.com.
          Copyright 2000 Example.com. All rights reserved.
      </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="purchaseOrder" type="PurchaseOrderType"/>
  <xsd:element name="comment" type="xsd:string"/>
  <xsd:complexType name="PurchaseOrderType">
      <xsd:sequence>
          <xsd:element name="shipTo" type="USAddress"/>
          <xsd:element name="billTo" type="USAddress"/>
          <xsd:element ref="comment" minOccurs="0"/>
          <xsd:element name="itemsList" type="Items"/>
      </xsd:sequence>
      <xsd:attribute name="orderDate" type="xsd:date"/>
  </xsd:complexType>
  <xsd:complexType name="USAddress">
      <xsd:sequence>
          <xsd:element name="name" type="xsd:string"/>
          <xsd:element name="street" type="xsd:string"/>
          <xsd:element name="city" type="xsd:string"/>
          <xsd:element name="state" type="xsd:string"/>
          <xsd:element name="zip" type="xsd:decimal"/>
      </xsd:sequence>
      <xsd:attribute name="country" type="xsd:NMTOKEN"
fixed="US"/>
  </xsd:complexType>
  <xsd:complexType name="Items">
      <xsd:sequence>
          <xsd:element name="item" minOccurs="0" maxOccurs="unbounded">
              <xsd:complexType>
                  <xsd:sequence>
                      <xsd:element name="productName" type="xsd:string"/>
                      <xsd:element name="quantity">
                          <xsd:simpleType>
                              <xsd:restriction base="xsd:positiveInteger">
                                  <xsd:maxExclusive value="100"/>
                              </xsd:restriction>
                          </xsd:simpleType>
                        </xsd:element>
                      <xsd:element name="USPrice" type="xsd:decimal"/>
                      <xsd:element ref="comment" minOccurs="0"/>
                      <xsd:element name="shipDate" type="xsd:date" minOccurs="0"/>
                  </xsd:sequence>
                  <xsd:attribute name="partNum" type="SKU" use="required"/>
              </xsd:complexType>
          </xsd:element>
      </xsd:sequence>
  </xsd:complexType>
  <!-- Stock Keeping Unit, a code for identifying products -->
  <xsd:simpleType name="SKU">
      <xsd:restriction base="xsd:string">
          <xsd:pattern value="\d{3}-[A-Z]{2}"/>
      </xsd:restriction>
  </xsd:simpleType>
</xsd:schema>