CODEWITHSUNDEEP
xmlxsd
Vilx-
Vilx-

Reputation: 106904

Is an empty complexType valid in an XSD?

I have an XML schema which I need to process and in the middle of it there is this line:

<xsd:complexType name="SomeName"/>

Is this valid XSD schema, or should a complexType always have some kind of content (child elements, attributes, anything)?

Upvotes: 2

Views: 3834

Answers (2)

tolanj
tolanj

Reputation: 3724

Yes this is a perfectly valid 'empty element'. Often used as a 'flag'. Take a look at http://www.w3schools.com/schema/schema_complex_empty.asp. That example includes a type with an attribute, but the discussion is valid.

[EDIT - new URL] https://www.w3schools.com/xml/schema_complex_empty.asp

Upvotes: 1

lexicore
lexicore

Reputation: 43651

Yes, it is valid.

See the schema for the schema.

 <xs:complexType name="complexType" abstract="true">
  <xs:complexContent>
   <xs:extension base="xs:annotated">
    <xs:group ref="xs:complexTypeModel"/>
    <xs:attribute name="name" type="xs:NCName"/>
    <xs:attribute name="mixed" type="xs:boolean" use="optional" default="false"/>
    <xs:attribute name="abstract" type="xs:boolean" use="optional" default="false"/>
    <xs:attribute name="final" type="xs:derivationSet"/>
    <xs:attribute name="block" type="xs:derivationSet"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

 <xs:group name="complexTypeModel">
  <xs:choice>
      <xs:element ref="xs:simpleContent"/>
      <xs:element ref="xs:complexContent"/>
      <xs:sequence>
       <xs:group ref="xs:typeDefParticle" minOccurs="0"/>
       <xs:group ref="xs:attrDecls"/>
      </xs:sequence>
  </xs:choice>
 </xs:group>

 <xs:group name="attrDecls">
  <xs:sequence>
   <xs:choice minOccurs="0" maxOccurs="unbounded">
    <xs:element name="attribute" type="xs:attribute"/>
    <xs:element name="attributeGroup" type="xs:attributeGroupRef"/>
   </xs:choice>
   <xs:element ref="xs:anyAttribute" minOccurs="0"/>
  </xs:sequence>
 </xs:group>

So the minimum would be:

<xs:complexType name="someNCName"/>

Which is the case in your question.

Upvotes: 3

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