"anyType" Built-in Datatype Values and Representations

This section provides a tutorial example to show built-in datatype 'anyType' valid values and representations. Everything, including XML structure, is a valid 'anyType' lexical representation.

To fully understand built-in datatypes defined in XSD 1.1, we need to spend time to read the specification and writing test XSD documents and XML documents for each datatype. Let's start with the first special built-in datatype "anyType" in this section.

"anyType" is a built-in datatype designed to be a wildcard datatype to represent any simple or complex values with these rules:

To verify these rules, I wrote this simple XSD document:

<?xml version="1.1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<!-- anyType_datatype_test.xsd
 - Copyright (c) 2013, HerongYang.com, All Rights Reserved.
-->
<xs:element name="AnyType_Datatype_Test">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="AnyType" type="xs:anyType" 
        maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

With <AnyType> element is declared as "anyType", anything can be placed inside the element. Here is an XML document with some examples:

<?xml version="1.1"?>
<AnyType_Datatype_Test>
<!-- anyType_datatype_test.xml
 - Copyright (c) 2013, HerongYang.com, All Rights Reserved.
-->
<!-- Everything is valid in "AnyType" elements -->
  <AnyType>   Everything is valid! </AnyType>
  <AnyType>   1971-05-16T00:00:01  </AnyType>
  <AnyType>   &#x5934;             </AnyType>
  <AnyType>   Hello <b>Herong</b>! </AnyType>
  <AnyType>   Hello <b size="9">Herong</b>! </AnyType>
  <AnyType>   
     <AnyType>   Hello <b size="9">Herong</b>! </AnyType>
  </AnyType>
</AnyType_Datatype_Test>

If you want validate this XML document, you can try it the Java XSD validation tool I wrote earlier in this book. You will get no errors:

c:\Progra~1\Java\jdk1.7.0_07\bin\java XsdSchemaValidator 
   anytype_datatype_test.xsd anytype_datatype_test.xml

Passed.

To show you that "anyType" is not allowed for declaring XML attributes, I wrote this invalid XSD document:

<?xml version="1.1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<!-- anyType_datatype_invalid_test.xsd
 - Copyright (c) 2013, HerongYang.com, All Rights Reserved.
-->
<xs:element name="AnyType_Datatype_Test">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="AnyType" type="xs:anyType" 
        maxOccurs="unbounded"/>

      <xs:element name="Attribute_Test" maxOccurs="unbounded">
        <xs:complexType>
          <!-- "anyType" is a complex type. 
               It can not be used for attributes -->
          <xs:attribute name="AnyType" type="xs:anyType"/>
        </xs:complexType>
      </xs:element>

    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

If you validate the same example XML document with this XSD document, you will see this error:

c:\Progra~1\Java\jdk1.7.0_07\bin\java XsdSchemaValidator 
   anyType_datatype_invalid_test.xsd anytype_datatype_test.xml

org.xml.sax.SAXParseException; systemId: 
   anyType_datatype_invalid_test.xsd; 
   lineNumber: 16; columnNumber: 59; src-resolve: 
   Cannot resolve the name 'xs:anyType' to a(n) 
   'simpleType definition' component.

java.lang.NullPointerException

Last update: 2013.

Table of Contents

 About This Book

 Introduction to XML Schema

 XML Editor and Schema Processor - XMLPad

 Java API for XML Processing - JAXP

 JAXP - XML Schema (XSD) Validation

 Xerces2 Java Parser - Java API of XML Parsers

 Using Xerces2 Java API

 XML Schema Language - Basics

Introduction of XSD Built-in Datatypes

 Overview of XSD 1.1 Built-in Datatypes

 List of Built-in Datatypes

 Datatypes, Values and Representations

 Datatypes, Values and Representations - Example

 Built-in Datatypes Lexical Representation Examples

 Declaring Elements and Attributes with Built-in Datatypes

 Defining New Datatypes with Built-in Datatypes

"anyType" Built-in Datatype Values and Representations

 "anySimpleType" Built-in Datatype Values and Representations

 "anyAtomicType" Built-in Datatype Values and Representations

 "string" and Its Derived Datatypes

 "decimal" and Its Derived Datatypes

 "dateTime" and Its Related Datatypes

 Miscellaneous Built-in Datatypes

 Facets, Constraining Facets and Restriction Datatypes

 "simpleType" - Defining Your Own Simple Datatypes

 Complex Element Declaration

 Identity-Constraints: unique, key and keyref

 Assertion as Custom Validation Rules

 XML Schema Location and Namespace in XML Documents

 Overriding Element Types in XML Documents

 Linking Multiple Schema Documents Together

 Glossary

 References

 PDF Printing Version