"NCName" Datatype Values and Representations

This section describes the built-in datatype 'NCName' designed to support XML element and attribute names with no namespace prefix. 'NCName', stands for 'Non-Colonized Name', datatype is derived from 'Name' by removing ':' from the 'Name' value pattern.

If you look at string pattern used to define "Name" values, you will see colon ":" is allowed in "Name" values. This is needed to support XML element names that uses namespances like "xs:complexType".

In order to support "Name" values without ":", XSD provides another datatype called "NCName" stands for "Non-Colonized Name".

"NCName" is a datatype derived from the "Name" datatype by removing ":" from the "Name" value pattern.

Here is a sample XSD document that defines a sub element <NCName> to use "NCName" values:

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

Here is a sample XML document that contains <NCName> elements to test that definition:

<?xml version="1.1"?>
<!-- NCName_datatype_test.xml
 - Copyright (c) 2013, HerongYang.com, All Rights Reserved.
-->
<NCName_Datatype_Test>

<!-- 5 valid "NCName" elements -->
  <NCName>name_datatype_test</NCName>
  <NCName>complexType</NCName>
  <NCName>   w3.org  </NCName>
  <NCName>     head  </NCName>
  <NCName>   &#x5934;</NCName>

<!-- 5 invalid "NCName" elements -->
  <NCName>   xs:token</NCName>
  <NCName>complex Type</NCName>
  <NCName>      (html)</NCName>
  <NCName>    xs+token</NCName>
  <NCName>    1st_head</NCName>
</NCName_Datatype_Test>

Again, the JDK 1.7 tool XsdSchemaValidator.java works nicely on this test. It reports 5 groups of errors for the last 5 invalid elements. But error messages do not provide the "NCName" string pattern

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

"string" and Its Derived Datatypes

 "string" Datatype Values and Representations

 "normalizedString" Datatype Values and Representations

 "token" Datatype Values and Representations

 "language" Datatype Values and Representations

 "language" Datatype Values - Invalid Inputs

 "Name" Datatype Values and Representations

 "NMTOKEN" Datatype Values and Representations

"NCName" Datatype Values and Representations

 "ENTITY" Datatype Values and Representations

 "ID" Datatype Values and Representations

 "IDREF" Datatype Values and Representations

 "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