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Contents > Simple tasks > Empty element

Empty element

  1. XML Schema
  2. Relax NG

Please, send all comments, bug-reports, and contributions to Jiri.Jirat@systinet.com. Thank you very much.

1. XML Schema

We want to have the root element to be named "AAA", from null namespace and empty. The empty element is defined as a "complexType" with a "complexContent" which is a restriction of "anyType", but without any elements.

Valid document


<AAA xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />

Correct XML Schema (correct_0.xsd)


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" >

  <xsd:element name="AAA">
    <xsd:complexType>
      <xsd:complexContent>
        <xsd:restriction base="xsd:anyType"/>
      </xsd:complexContent>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>

2. Relax NG

To specify, that element must be empty, use the "empty" element.

Valid document


<AAA xmlns=""/>

Correct Relax NG schema (correctRelax_0.rng)


<grammar xmlns="http://relaxng.org/ns/structure/1.0" >

  <start>
    <element>
      <name ns="">AAA</name>
      <empty/>
    </element>
  </start>
</grammar>

Correct Relax NG schema (correctRelax_1.rng)
This short version is also valid.


<element xmlns="http://relaxng.org/ns/structure/1.0" >
  <name ns="">AAA</name>
  <empty/>
</element>