WSDL

WSDL describes
- What the service does
- Where it can be found
- How the service can be invoked

Two main elements
- Functional description: where, how and what of the service
- Nonfunctional description: why (service should be invoked); who (the service provider is)

- Root element is <definitions>
- Namespace URIs
- Use XML schema to describe datatypes

Abstract (service interface definition)
- Datatypes:
- Messages:
- Operations

Concrete
- Specific bindings:
- Service endpoint URLs:

Child elements of
- <types>(1): datatypes be exchanged in messages; no need if built-in simple XML schema datatypes used
- <message>: structure of message (parameters, return types); made up of (datatypes in )
- (1): web service operations (abstract interface definition); represented by (method); In WSDL 2.0, called
- : message encoding, transport protocol for
- : logical grouping of ports. defines service endpoints and associated addresses

<definitions>







<types>













<message> & <portType>















<binding>









In some cases, may be in interface definition. This is because Mbinding> is reusable when registering WSDL using UDDI









<service>








Across multiple files
Splitting documents into
- service interface definition: - placed on an established website that everyone can access
- Service implementation definition: - describes how the service interface definition has implemented at a specific network endpoint
* Ensure: with the same targewt namespace



SOAP fault msg, param in header














Fault information
- Abstract message format for error message
- Define fault Information in (regular message) or () or ( )
- <soap:header><soap:headerfault>








SOAP fault msg, param in header














Transmission primitives
- Request-response
- One-way operations
- Notification operations
- Solicit-response (endpoint “pushes” message and receive a correlated message)

Binding
- Using HTTP GET/POST operations
- MIME extensions