XSD Tutorials - Herong's Tutorial Examples - v5.23, by Herong Yang
"simpleType" Components with "restriction" Child Components
This section describes the 'restriction' child component in 'simpleType' component. 'restriction' child components are used to reduce the value space on a base datatype by changing its constraining facets.
In earlier tutorials, we learned datatype facets can be modified to create new datatypes using "restriction" components. Now let's take closer look at the "restriction" component.
Here is an XSD template showing you how to use the "restriction" as a child component in a "simpleType" component:
Format 1: <simpleType ...> <restriction base="base_type"> facet component facet component ... </restriction> </simpleType> Format 2: <simpleType ...> <restriction> <simpleType ...> definition of the base datatype </simpleType> facet component facet component ... </restriction> </simpleType>
Some notes on using the "restriction" component:
For example, the following XSD document uses "restriction" components to define 2 new simple datatypes:
<?xml version="1.1"?> <!-- restriction_simpleType_test.xsd - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved. --> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="Restriction_SimpleType_Test"> <xs:complexType> <xs:sequence> <xs:element name="IPAddress" maxOccurs="unbounded"> <!-- "restriction" with no "base" attribute --> <xs:simpleType> <xs:restriction> <xs:simpleType> <xs:restriction base="xs:string"> <xs:pattern value="\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"/> </xs:restriction> </xs:simpleType> <xs:maxLength value="15"/> </xs:restriction> </xs:simpleType> </xs:element> <xs:element name="Port" maxOccurs="unbounded"> <!-- "restriction" with "base" attribute --> <xs:simpleType> <xs:restriction base="xs:unsignedByte"> <xs:enumeration value="80"/> <xs:enumeration value="23"/> </xs:restriction> </xs:simpleType> </xs:element> </xs:sequence> </xs:complexType> </xs:element> </xs:schema>
Here is a sample XML document to test the above XSD document:
<?xml version="1.1"?> <!-- restriction_simpleType_test.xml - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved. --> <Restriction_SimpleType_Test> <!-- Valid "IPAddress" values --> <IPAddress>127.0.0.1</IPAddress> <!-- Invalid "IPAddress" values --> <IPAddress>::1:</IPAddress> <!-- Valid "Port" values --> <Port>80</Port> <!-- Invalid "Port" values --> <Port>8080</Port> </Restriction_SimpleType_Test>
When validating this XML document with my XsdSchemaValidator.java program presented earlier in the book, I get these errors:
herong> java XsdSchemaValidator ^^^ restriction_simpleType_test.xsd restriction_simpleType_test.xml Error: Line number: 11 Column number: 31 Message: cvc-pattern-valid: Value '::1:' is not facet-valid with respect to pattern '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}' for type '#AnonType_IPAddressRestriction_SimpleType_Test'. Error: Line number: 11 Column number: 31 Message: cvc-type.3.1.3: The value '::1:' of element 'IPAddress' is not valid. Error: Line number: 17 Column number: 21 Message: cvc-enumeration-valid: Value '8080' is not facet-valid with respect to enumeration '[80, 23]'. It must be a value from the enumeration. Error: Line number: 17 Column number: 21 Message: cvc-type.3.1.3: The value '8080' of element 'Port' is not valid. Failed with errors: 4
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
"simpleType" Components - User-Defined Simple Datatypes
►"simpleType" Components with "restriction" Child Components
"simpleType" Components with "union" Child Components
"simpleType" Components with "list" Child Components
Atomic, List, Atomic Union and List Union Datatypes
Constraining Facets on List Datatypes
Constraining Facets on Union Datatypes
Nested List Datatypes - Not Allowed
Nested Atomic and List Union 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