Hi.
  I have the following snippet of XML:
  <Box type="Big"><Pencil>My</Pencil></Box>

  I get the following error message when I try to validate the XML against the schema:
  The content of complex type '{no name}' is 'empty'. This forbids any content for element 'Box'.

  Does anybody know why? Please help.

The schema I used to validate the XML is the following:
<xs:element name="Box">
  <xs:complexType>
    <xs:restriction base="BoxType">
      <xs:attribute name="type" default="Big">
        <xs:enumeration value="Big"/>
        <xs:enumeration value="Small"/>
      </xs:attribute>
    </xs:restriction>
  </xs:complexType>
</xs:element>

<xs:complexType name=BoxType">
  <xs:sequence>
    <xs:element name="Pencil" minOccurs="0" maxOccurs="1">
      <xs:simpleType>
         <xs:restriction base="xs:string">
            <xs:minLength value="1"/>
         </xs:restriction>
      </xs:simpleType>
    </xs:element>
    <xs:element name="Puzzle" minOccurs="0" maxOccurs="1"/>
  </xs:sequence>
</xs:complexType>


Appreciate any help.

Most schema's I've seen when you are refering to a type you have defined you need to prefix it with a namespace which is declared above. Something like below:

/- Sam Judson : Wrox Technical Editor -/

I'm amazed this got as far as validating the source document (what schema processor are you using?). The schema is full of errors that should have been reported before it got anywhere near validating an instance.

Firstly, there's a missing quote in

<xs:complexType name=BoxType">

I mention this only because it gives a rather big clue that the schema you have posted is not the one you actually used, so anything else I say might be nonsense.

This is what Saxon says about your "schema":

Error at xs:restriction on line 6 of file:/c:/temp/test.xsd:
  Element xs:restriction cannot appear here: expected one of {choice, sequence, assert,
  annotation, attributeGroup, anyAttribute, simpleContent, all, attribute, group, complexContent}
Error at xs:enumeration on line 8 of file:/c:/temp/test.xsd:
  Element <xs:enumeration> is not allowed as a child of <xs:attribute>
Error at xs:enumeration on line 9 of file:/c:/temp/test.xsd:
  Element <xs:enumeration> is not allowed as a child of <xs:attribute>
Schema processing failed: 3 errors were found while processing the schema

The BoxType type appears to be OK. The anonymous complex type defined in the Box element declaration is not. If you want to add an attribute, then you need to extend the type, not restrict it. And if the attribute has valid values Big and Small then you need to define a simple type that restricts xs:string with the restriction defining these two enumeration values, and then reference this type from the attribute declaration.


Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference