Wsdl

Web Service Description Language

1. 11
WSDL: Web Service WSDL: Web Service
Description LanguageDescription Language
Gary SharpGary Sharp
Mike BreakironMike Breakiron

2. 2
OutlineOutline
What and whyWhat and why
WSDL document structureWSDL document structure
Sections and elementsSections and elements
–types, messages, portTypes, bindings, and servicestypes, messages, portTypes, bindings, and services
NamespacesNamespaces
Demo1 – create a web service and its WSDL Demo1 – create a web service and its WSDL
documentdocument
Demo2 – XMethods WSDL interpretationDemo2 – XMethods WSDL interpretation
WSDL referencesWSDL references

3. 3
What is WSDL?What is WSDL?
Web Service Description LanguageWeb Service Description Language
WSDL is a document written in XMLWSDL is a document written in XML
The document describes a Web serviceThe document describes a Web service
Specifies the location of the service and Specifies the location of the service and
the methods the service exposesthe methods the service exposes

4. 4
Why WSDL?Why WSDL?
Without WSDL, calling syntax must be Without WSDL, calling syntax must be
determined from documentation that must determined from documentation that must
be provided, or from examining wire be provided, or from examining wire
messages messages
With WSDL, the generation of proxies for With WSDL, the generation of proxies for
Web services is automated in a truly Web services is automated in a truly
language- and platform-independent way language- and platform-independent way

5. 5
Where does WSDL fit?Where does WSDL fit?
SOAP is the envelope containing the SOAP is the envelope containing the
messagemessage
WSDL describes the serviceWSDL describes the service
UDDI is a listing of web services described UDDI is a listing of web services described
by WSDLby WSDL

6. 6
Document StructureDocument Structure
Written in XMLWritten in XML
Two types of sections Two types of sections
–Abstract and ConcreteAbstract and Concrete
AbstractAbstract sections define SOAP messages sections define SOAP messages
in a platform- and language-independent in a platform- and language-independent
manner manner
Site-specific matters such as serialization Site-specific matters such as serialization
are relegated to the are relegated to the ConcreteConcrete sections sections

7. 7
Abstract DefinitionsAbstract Definitions
Types: Types: Machine- and language-Machine- and language-
independent type definitions. independent type definitions.
Messages: Messages: Contains function parameters Contains function parameters
(inputs are separate from outputs) or (inputs are separate from outputs) or
document descriptions. document descriptions.
PortTypes: PortTypes: Refers to message definitions Refers to message definitions
in Messages section that describe function in Messages section that describe function
signatures (operation name, input signatures (operation name, input
parameters, output parameters). parameters, output parameters).

8. 8
Concrete DescriptionsConcrete Descriptions
Bindings: Bindings: Specifies binding(s) of each Specifies binding(s) of each
operation in the PortTypes section. operation in the PortTypes section.
Services: Services: Specifies port address(es) of Specifies port address(es) of
each binding. each binding.

9. 9
OperationOperation
An An operationoperation is similar to a function in a is similar to a function in a
high level programming languagehigh level programming language
A message exchange is also referred to A message exchange is also referred to
as an operation as an operation
Operations are the focal point of Operations are the focal point of
interacting with the serviceinteracting with the service

10. 10
Big PictureBig Picture

11. 11
An ExampleAn Example
<?xml version="1.0" encoding="UTF-8" ?> <?xml version="1.0" encoding="UTF-8" ?>
This first line declares the document as an This first line declares the document as an
XML document.XML document.
Not required, but helps the XML parser Not required, but helps the XML parser
determine whether to parse the file or determine whether to parse the file or
signal an errorsignal an error

12. 12
Types SectionTypes Section
The The typetype element defines the data types element defines the data types
that are used by the web service. that are used by the web service.
<xsd:complexType name="PERSON"><xsd:complexType name="PERSON">
<xsd:sequence> <xsd:sequence>
<xsd:element name="firstName“ type="xsd:string"/> <xsd:element name="firstName“ type="xsd:string"/>
<xsd:element name="lastName" type="xsd:string"/> <xsd:element name="lastName" type="xsd:string"/>
<xsd:element name="ageInYears" type="xsd:int"/> <xsd:element name="ageInYears" type="xsd:int"/>
</xsd:sequence> </xsd:sequence>
</xsd:complexType></xsd:complexType>

13. 13
Messages SectionMessages Section
A A messagemessage element defines parameters element defines parameters
The name of an output message element ends The name of an output message element ends
in "Response" by convention in "Response" by convention
<message name="Simple.foo"> <message name="Simple.foo">
<part name="arg" type="xsd:int"/> <part name="arg" type="xsd:int"/>
</message> </message>
<message name="Simple.fooResponse"> <message name="Simple.fooResponse">
<part name="result" type="xsd:int"/> <part name="result" type="xsd:int"/>
</message> </message>

14. 14
PortTypes SectionPortTypes Section
Defines a web service, the operations that can be Defines a web service, the operations that can be
performed, and the messages that are involved. performed, and the messages that are involved.
<portType name="SimplePortType"> <portType name="SimplePortType">
<operation name="foo" parameterOrder="arg" > <operation name="foo" parameterOrder="arg" >
<input message="wsdlns:Simple.foo"/> <input message="wsdlns:Simple.foo"/>
<outputmessage="wsdlns:Simple.fooResponse"/> <outputmessage="wsdlns:Simple.fooResponse"/>
</operation> </operation>
</portType> </portType>

15. 15
Bindings SectionBindings Section
The The bindingbinding element defines the message element defines the message
format and protocol details for each port.format and protocol details for each port.
<operation name="foo"> <operation name="foo">
<soap:operation soapAction="http://tempuri.org/action/Simple.foo"/><soap:operation soapAction="http://tempuri.org/action/Simple.foo"/>
<input> <input>
<soap:body use="encoded" <soap:body use="encoded"
namespace="http://tempuri.org/message/" namespace="http://tempuri.org/message/"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /> encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" />
</input> </input>
<output> <output>
<soap:body use="encoded“ <soap:body use="encoded“
namespace="http://tempuri.org/message/“namespace="http://tempuri.org/message/“
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /> encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" />
</output> </output>
</operation> </operation>

16. 16
The Port ElementThe Port Element
Each <port> element associates a location Each <port> element associates a location
with a <binding> in a one-to-one fashion with a <binding> in a one-to-one fashion
<port name="fooSamplePort" <port name="fooSamplePort"
binding="fooSampleBinding"> binding="fooSampleBinding">
<soap:address <soap:address
location="http://carlos:8080/fooService/foo.asp"/> location="http://carlos:8080/fooService/foo.asp"/>
</port> </port>

17. 17
Services SectionServices Section
A collection of related endpoints, where an A collection of related endpoints, where an
endpoint is defined as a combination of a endpoint is defined as a combination of a
binding and an address binding and an address
<service name="FOOSAMPLEService"> <service name="FOOSAMPLEService">
<port name="SimplePort“ <port name="SimplePort“
binding="wsdlns:SimpleBinding">binding="wsdlns:SimpleBinding">
<soap:address <soap:address
location="http://carlos:8080/FooSample/ location="http://carlos:8080/FooSample/
FooSample.asp"/> FooSample.asp"/>
</port> </port>
</service> </service>

18. 18
An ExampleAn Example
<message name="Simple.foo"> <message name="Simple.foo">
<part name="arg" type="xsd:int"/> <part name="arg" type="xsd:int"/>
</message> </message>
<message name="Simple.fooResponse"> <message name="Simple.fooResponse">
<part name="result" type="xsd:int"/> <part name="result" type="xsd:int"/>
</message> </message>
<portType name="SimplePortType"> <portType name="SimplePortType">
<operation name="foo" parameterOrder="arg" > <operation name="foo" parameterOrder="arg" >
<input message="wsdlns:Simple.foo"/> <input message="wsdlns:Simple.foo"/>
<output message="wsdlns:Simple.fooResponse"/> <output message="wsdlns:Simple.fooResponse"/>
</operation> </operation>
</portType> </portType>
The above describes what kind of C/C++ function call?The above describes what kind of C/C++ function call?
int foo(int arg); int foo(int arg);

19. 19
NamespacesNamespaces
The purpose of namespaces is to avoid naming The purpose of namespaces is to avoid naming
conflicts. conflicts.
Imagine two complimentary web services, Imagine two complimentary web services,
named A and B, each with an element named named A and B, each with an element named
“foo”. “foo”.
Each instance of foo can be referenced as A:foo Each instance of foo can be referenced as A:foo
and B:fooand B:foo
Example: "xmlns:xsd" defines a shorthand (xsd) Example: "xmlns:xsd" defines a shorthand (xsd)
for the namespace for the namespace
See See http://www.w3.org/2001/XMLSchemahttp://www.w3.org/2001/XMLSchema. .

20. 20
DemoDemo
Create a web service and generate its Create a web service and generate its
WSDL documentWSDL document

21. 21
DemoDemo
Demo of XMethods WSDL interpretationDemo of XMethods WSDL interpretation

22. 22
WSDL References [Primary]WSDL References [Primary]
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwebsrv/html/wsdlexplained.asphttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwebsrv/html/wsdlexplained.asp
-a good overview of WSDL-a good overview of WSDL
http://msdn.microsoft.com/library/default.ahttp://msdn.microsoft.com/library/default.a
sp?url=/library/en-sp?url=/library/en-
us/dnwebsrv/html/understandWSDL.aspus/dnwebsrv/html/understandWSDL.asp
-another good WSDL description-another good WSDL description

23. 23
http://www.xmethods.com/ve2/Tools.pohttp://www.xmethods.com/ve2/Tools.po
-WSDL analyzer-WSDL analyzer
http://soap.amazon.com/schemas2/Amazhttp://soap.amazon.com/schemas2/Amaz
onWebServices.wsdlonWebServices.wsdl
-Amazon’s WSDL document-Amazon’s WSDL document
http://api.google.com/GoogleSearch.wsdlhttp://api.google.com/GoogleSearch.wsdl
-Google’s WSDL document-Google’s WSDL document
WSDL References [Secondary]WSDL References [Secondary]