Tutorial Addendum On XML Technologies - XSD Syntax

Empty XML Elements

    

Empty XML Element: A appropriate circuitous XML aspect that has

    

one aspect or added and no adolescent argument nodes. Abandoned XML elements must

    

be authentic with circuitous data types in the afterward format:

    

 

    
<xsd:complexType name="my_data_type">

    
 <xsd:attribute name="attribute_a" type="data_type_a"/>

    
 <xsd:attribute name="attribute_b" type="data_type_b"/>

    
 ...

    
</xsd:complexType>

    

Anomymous Data Types

    

If data blazon is specific to a adolescent aspect in a ancestor data type, and there is not

    

need to allotment it with data types alfresco the ancestor data type, you can ascertain it

    

as bearding data blazon - a non-named data blazon authentic inline. For example, the

    

following code:

    

 

    
<xsd:complexType name="my_data_type">

    
 <xsd:sequence>

    
  <xsd:element name="setting">

    
   <xsd:complexType>

    
    <xsd:sequence>

    
     <xsd:element name="property" type="xsd:string"/>

    
     <xsd:element name="value" type="xsd:integer"/>

    
    </xsd:sequence>

    
   </xsd:complexType>

    
  </xsd:element>

    
 </xsd:sequence>

    
</xsd:complexType>

    

defines "my_data_type" which has a "setting" element, which has an bearding data type

    

defined inline.

    

Sample XSD book - dictionary.xsd

    

Let s alter my concordance XML book with XSD link, dictionary_xsd.xml:

    

 

    
<?xml version="1.0"?>

    
<dictionary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

    
 xsi:noNamespaceSchemaLocation="dictionary.xsd">

    
<!-- dictionary_xsd.xml

    
     Absorb (c) 2002 by Dr.  Yang

    
-->

    
 <word acronym="true">

    
  <name>XML</name>

    
  <definition reference="'s Notes">eXtensible Markup 

    
Language.</definition>

    
  <update date="2002-12-23"/>

    
 </word>

    
 <word symbol="true">

    
  <name><</name>

    
  <definition>Mathematical attribute apery the "less than" analytic 

    
operation, like: 1<2.</definition>

    
  <definition>Reserved attribute in XML apery the alpha of 

    
tags, like: <![CDATA[<p>Hello world!</p>]]>

    
  </definition>

    
 </word>

    
 <word symbol="false" acronym="false">

    
  <name>extensible</name>

    
  <definition>Capable of getting extended.</definition>

    
 </word>

    
</dictionary>

    

And address an XSD validation file, dictionary.xsd:

    

 

    
<?xml version="1.0"?>

    
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

    
 <xsd:element name="dictionary" type="dictionaryType"/>

    
 <xsd:complexType name="dictionaryType">

    
  <xsd:sequence>

    
   <xsd:element name="word" type="wordType" maxOccurs="unbounded"/>

    
  </xsd:sequence>

    
 </xsd:complexType>

    
 <xsd:complexType name="wordType">

    
  <xsd:sequence>

    
   <xsd:element name="name" type="xsd:string"/>

    
   <xsd:element name="definition" type="definitionType" 

    
    maxOccurs="unbounded"/>

    
   <xsd:element name="update" type="updateType" minOccurs="0"/>

    
  </xsd:sequence>

    
  <xsd:attribute name="acronym" type="xsd:boolean" use="optional"/>

    
  <xsd:attribute name="symbol" type="xsd:boolean" use="optional"/>

    
 </xsd:complexType>

    
 <xsd:complexType name="definitionType" mixed="true">

    
  <xsd:attribute name="reference" type="xsd:string"/>

    
 </xsd:complexType>

    
 <xsd:complexType name="updateType">

    
  <xsd:attribute name="date">

    
   <xsd:simpleType>

    
    <xsd:restriction base="xsd:string">

    
     <xsd:pattern value="p{Nd}{4}-p{Nd}{2}-p{Nd}{2}"/>

    
    </xsd:restriction>

    
   </xsd:simpleType>

    
  </xsd:attribute>

    
 </xsd:complexType>

    
</xsd:schema>

    

Note that:

    

    
• Anonymous data blazon is acclimated to ascertain my "date" attribute.


    
• A "pattern" angle is acclimated to bind a cord blazon with a approved expression.


    
• "dicstionary_xsd.xml" anesthetized XML Spy 5.3 XSchema validation.