Sample : Derived By Extension
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Sample : Derived By Extension
| Summary This sample shows how a complex type may be extended, and how the base and extended types can be manipulated in code. Details The Schema A global base type Address is defined (all base types must be global). The elements CAN_Address and GBR_Address then extended Address in order to add additional elements. The Person element contains a child element HomeAddress of type Address. In place of Address any type that is based on Address (including Address itself) can be used (CAN_Address and GBR_Address). If an element is added to Person:HomeAddress of a type other than the Address, then we need to identify the type of the element used (for validation purposes), this means placing a xs:type="" attribute against the element. This is automatically done for you by the generated classes. Generated Code The element Address is a base element to CAN_Address and GBR_Address, and Address can be created as an element in its own right. This means that where ever Address can be used CAN_Address and GBR_Address can be used in its place. In order to implement this in the generated code, an abstract base class IAddress is introduced. All of the classes generated from Address, CAN_Address and GBR_Address implement this IAddress interface. |
XSD Source Files
  DerivedByExtension.xsd |
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:complexType name="Address">
<xs:sequence>
<xs:element name="Name" type="xs:string"/>
<xs:element name="Street" type="xs:string"/>
<xs:element name="City" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="CAN_Address">
<xs:complexContent>
<xs:extension base="Address">
<xs:sequence>
<xs:element name="Province" type="xs:string"/>
<xs:element name="PostalCode" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="GBR_Address">
<xs:complexContent>
<xs:extension base="Address">
<xs:sequence>
<xs:element name="County" type="xs:string"/>
<xs:element name="PostCode" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="Person">
<xs:complexType>
<xs:sequence>
<xs:element name="Age" type="xs:unsignedByte"/>
<xs:element name="HomeAddress" type="Address"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
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| Schema Diagrams |
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| Sample Name | Description | C++ | C# | Java | VB.Net | VB6 |
| Use of Base Address Type | The sample demonstrates the use of the base Address type. Note other elements derived from Address may be used in its place (See Samples 2 and 3). | Example | Example | Example | Example | Example |
| Use of Derived Base GBR_Address Type | The sample demonstrates the use of the derived type GBR_Address. Note the type specified in Person is 'Address' however any element deriving from it may used in its place. | Example | Example | Example | Example | Example |
| Use of Derived Can_Address Type | The sample demonstrates the use of the derived type Can_Address. Note the type specified in Person is 'Address' however any element deriving from it may used in its place. | Example | Example | Example | Example |
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