xsd 中的递归

Recursion in xsd

如何使用预定义的 complexType 在 xsd 模式中进行递归,如下所示:

  <xs:complexType name="style">
      <xs:attribute name="name" type="xs:string" use="optional" />
      <xs:attribute name="color" type="xs:string" use="optional" />
  </xs:complexType>

    <xs:complexType name="children">
      <xs:sequence>
        <xs:element name="div" type="style">
          <xs:complexType>
            <xs:sequence>
              <xs:element ref="children" minOccurs="0"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>

如果您希望以下 XML 有效,

<?xml version="1.1" encoding="utf-8" ?>
<children xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:noNamespaceSchemaLocation="try.xsd">
  <div name="John" color="red">
    <children>
      <div name="Mary" color="white"/>
      <div name="Fred" color="blue"/>
    </children>
  </div>
</children>

那么这个递归 XSD 将符合要求:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> 
  <xs:element name="children">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="div" minOccurs="0" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence>
              <xs:element ref="children" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:attribute name="name" type="xs:string" use="optional" />
            <xs:attribute name="color" type="xs:string" use="optional" />
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>