Complex Element Types

This section describes complex element types declared by 'complexType' statements. A complex element type defines an element that has at least one child element or at least one attribute.

Complex XML Element Type: An XML element that has at least one child element or at least one attribute. Complex XML elements must be defined with complex data types, which are defined by "complexType" statements:

<xsd:element name="element_name" type="my_type_name"/>
<xsd:complexType name="my_data_type">
 <xsd:sequence>
  <xsd:element name="child_element_1" type="data_type_1"/>
  <xsd:element name="child_element_2" type="data_type_2"/>
  ...
 </xsd:sequence>
 <xsd:attribute name="attribute_a" type="data_type_a"/>
 <xsd:attribute name="attribute_b" type="data_type_b"/>
 ...
</xsd:complexType>

where "attribute" statement is used to define an attribute, and "sequence" statement is used to define the group of child elements and the order the child elements should appear in the XML structure.

Note that "attribute" statements must appear after the child element definition statements.

Additional options are available for the "element" statement enclosed in the "sequence" statement:

 <xsd:sequence>
  <xsd:element name="child_element" type="data_type"
   minOccurs="0|1|...|unbounded" maxOccurs="0|1|...|unbounded" 
   mixed="true|false"/>
 </xsd:sequence>

where:

There is one additional options available for the "attribute" statement:

 <xsd:attribute name="attribute" type="data_type"
  use="optional|required"/>

where:

"sequence" is not the only way to group child elements. XSD provides 3 ways of grouping child element:

Of course, grouping statements can be nested.

Last update: 2014.

Table of Contents

 About This Book

 Introduction of XML (eXtensible Markup Language)

 XML File Syntax

 XML File Browsers

 DOM (Document Object Model) Programming Interface

 SAX (Simple API for XML) Programming Interface

 DTD (Document Type Definition) Introduction

 Syntaxes of DTD Statements

 Validating an XML Document against the Specified DTD Document Type

 XSD (XML Schema Definition) Introduction

Syntaxes of XSD Statements

 "schema" - The Schema Declaration Statement

 "element" - The Element Declaration Statement

 Simple Element Types with Built-in Data Types

 Simple Element Types with Extended Data Types

Complex Element Types

 Simple Content Element Types

 Empty Element Types

 Anonymous or Inline Data Types

 dictionary.xsd - A Sample XSD XML Schema File

 Validating XML Documents Against Specified XML Schemas

 XSL (Extensible Stylesheet Language) Introduction

 XSLT (XSL Transformations) Introduction

 Java Implementation of XSLT

 XPath (XML Path) Language

 XSLT Elements as Programming Statements

 Control and Generate XML Element in the Result

 XML Notepad - XML Editor

 XML Tools Plugin for Notepad++

 XML 1.1 Changes and Parsing Examples

 Outdated Tutorials

 References

 PDF Printing Version