XSD Tutorials - Herong's Tutorial Examples - v5.23, by Herong Yang
Redefining Old Datatypes - "redefine" Component
This section describes a tutorial example on how to redefine datatypes defined in other schema documents.
Some you may want to revise some datatype definitions in an existing schema and make a newer version. The new version of the schema document can use the "redefine" component to include the old schema document and redefine one or more datatypes defined in the old schema document. To use the "redefine" component, you need to remember the following rules:
Rule 1. The XML representation of an "redefine" component is an "redefine" element.
Rule 2. The "redefine" element must have the "schemaLocation" attribute to specify where to fetch the old schema document.
Rule 3. The "redefine" element must have one or more datatype definition components that redefine datatypes from the old schema document.
Rule 4. A redefined datatypes must have same name as the base datatype.
Rule 3. The "redefine" element must appear before any element declarations or type definitions.
Below is a tutorial sample schema named address_us_redefine.xsd that redefines the datatype "addressUsType" using the "redefine" component:
<?xml version="1.0"?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <xsd:annotation> <xsd:documentation>address_us_redefine.xsd - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved. </xsd:documentation> </xsd:annotation> <xsd:redefine schemaLocation="address_us.xsd"> <xsd:annotation> <xsd:documentation> Modifying the "addressUsType" definition </xsd:documentation> </xsd:annotation> <xsd:complexType name="addressUsType"> <xsd:complexContent> <xsd:extension base="addressUsType"> <xsd:sequence> <xsd:element name="country" type="xsd:string"/> </xsd:sequence> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:redefine> </xsd:schema>
As you can see, in this new version of the US address schema, we redefined the "addressUsType" datatype. We did not add any new element declaration. The "addressUs" element declaration in the old schema document is still valid. But it will take the new definition of "addressUsType. See the next section for examples of XML documents that conform to this new schema.
Table of Contents
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
Introduction of XSD Built-in Datatypes
"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
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
Schema Component Reuse - "include", "redefine" or "import"
Including Old Schema Documents - "include" Component
Including Old Schema Documents - Examples
Including Old Schema Documents - Errors
►Redefining Old Datatypes - "redefine" Component
Redefining Old Datatypes - XML Examples
Redefining Old Datatypes - Errors
Importing Declarations Across Namespaces - "import" Component
Importing Declarations Across Namespaces - Examples
Using Elements Declared in Different Namespaces