XSD Tutorials - Herong's Tutorial Examples - v5.23, by Herong Yang
Declaring Complex Elements with Simple Content
This section describes a tutorial example on how to define an element that accepts attributes and text content without sub elements using complexType with simpleContent.
A complex element with simple content is an element with text content and attributes, but no sub (child) element. This type of element can be declared with a "complexType" datatype with "simpleContent" containing some "attribute"s.
A good example of complex elements with simple content is the <textarea> element in HTML documents. It accepts a text string as the content with no sub (child) element and some attributes.
Rule 1. The "complexType" component defines a datatype for a complex element.
Rule 2. The "simpleContent" component used inside "complexType" specifies that the complex element should not have any sub (child) element.
Rule 3. The "extension" component inside "simpleContent" extends the specified base datatype for the content to include "attribute" declarations.
Rule 4. Each "attribute" component inside "extension" defines an additional attribute for the base datatype.
Here is an sample schema, complexType_simpleContent.xsd, that defines <textarea> to accept simple content and 3 attributes:
<?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <!-- complexType_simpleContent.xsd - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved. --> <xs:element name="textarea"> <xs:complexType> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="name" type="xs:string"/> <xs:attribute name="cols" type="xs:positiveInteger"/> <xs:attribute name="rows" type="xs:positiveInteger"/> </xs:extension> </xs:simpleContent> </xs:complexType> </xs:element> </xs:schema>
Let's try this schema on a sample XML document, complexType_simpleContent.xml, with some errors:
herong> type complexType_simpleContent.xml <?xml version="1.0"?> <textarea name="comment" cols="50" rows="l"> This book is <b>really</b> helpful... </textarea> herong> java XsdSchemaValidator complexType_simpleContent.xsd ^^^ complexType_simpleContent.xml Error: Line number: 2 Column number: 45 Message: cvc-datatype-valid.1.2.1: 'l' is not a valid value for 'integer'. Error: Line number: 2 Column number: 45 Message: cvc-attribute.3: The value 'l' of attribute 'rows' on element 'textarea' is not valid with respect to its type, 'positiveInteger'. Error: Line number: 4 Column number: 12 Message: cvc-complex-type.2.2: Element 'textarea' must have no element [children], and the value must be valid. Failed with errors: 3
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
Complex Element vs. Simple Element
►Declaring Complex Elements with Simple Content
Declaring Complex Elements with Attributes Only
Declaring Complex Elements with Sub Elements Only
Declaring Complex Elements with Attributes and Sub Elements
Declaring Complex Elements with Attributes, Sub Elements & Text Content
Using Shorthand for "complexContent" with "restriction"
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