EGEE is a project funded by the European Union under contract IST WSDL Web Service Description Language

Talk titledate2 Objectives The role of WSDL The structure of a WSDL document types message portType binding service

Talk titledate3 What is the function of WSDL WSDL represents a contract between the consumer and provider of a service. It should guarantee a service format.

Talk titledate4 The function of WSDL WSDL describes a services exposed interface It is what a client sees of your service WSDL includes information about The data types it uses Parameters it requires and returns Groupings of functionality The protocol to be used to access the service The location or address of the service

Talk titledate5 WSDL Structure A WSDL document is an XML document

Talk titledate6 Referencing between sections Each section refers to elements defined in other sections

Talk titledate7 Simplified definitions Each defines things referenced by other sections

Talk titledate8 element <definitions targetNamespace=urn:3950 xmlns= xmlns:xsd= xmlns:soap= xmlnssoapenc= xmlns:tns= urn:3950> Acts like C/C++ #include, or Java import. Incorporates external namespaces

Talk titledate9 Namespaces WSDL uses a number of different namespaces including XML Schema Namespaces WSDL Namespaces SOAP Namespaces

Talk titledate10 The The types element contains XML Schemas defining the datatypes that are to be passed to and from the web service

Talk titledate11 The The element is used to define the messages that will be exchanged between the client and the service These message elements contain elements, which will be using types defined in the types element All the parts are namespace qualified

Talk titledate12 Relating messages and operations Web services are a messaging system For a normal method (operation) there will be generally two messages A message is required to pass the parameters in. A message is required to pass the return value out Even a void return requires an empty return message

Talk titledate13 Messaging void myMethod (parameter:type) Empty message Parameter:type 1. Message in 2. Message out In non-messaging languages this is hidden

Talk titledate14 The The types and messages have been defined, but they have not been defined in terms of where they fit in the functionality of the web service This is done within and elements A portType is analogous to a class An operation is analogous to a method in that class

Talk titledate15 Types of There are four distinct types of operation Synchronous Request-response - The service receives a message and sends a reply Solicit-response - The service sends a message and receives a reply message Asynchronous One-way - The service receives a message Notification - The service sends a message All of these can be defined in WSDL

Talk titledate16 Defining the type of operation Presence and order of input/output elements defines the type of operation. Request-response Solicit-response One-way only Notification only

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Talk titledate18 The element This element is used to define the mechanism that the client will actually use to interact with the web service There are three possibilities 1. SOAP 2. HTTP 3. MIME The most common choice is currently SOAP The binding element defines the protocol specific information for the portTypes previously defined

Talk titledate19 The binding tag The tag indicates that we will map a to a protocol Indicates we will be using the SOAP binding extensions to map the operations. The alternative to rpc is document. ( to use GET/POST use to use MIME use )

Talk titledate20 Example Below is an example of a binding element for SOAP

Talk titledate21 The final component of a WSDL file is the element The element defines elements that specify where requests should be sent The subelement identifies the URL of the service The precise content of elements will be dependent upon the mechanism, i.e. SOAP, HTTP or MIME

Talk titledate22 Overview of HelloService

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Talk titledate25 WSDL File for HelloService