Chapter 7: Creating and Consuming XML

Web Services Understanding XML Web Services

Creating XML Web Services

Deploying and Discovering XML Web Services

Consuming an XML Web Service

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Understanding XML Web Services

Overview of XML Web Services XML Web Services Infrastructure Communication Between the Client and the XML Web Service

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Overview of XML Web Services

XML Web service is a component . Using standard protocols, such as HTTP, XML, and SOAP, to

access the functionality . XML Web services use XML-based messaging to send and

receive data . Aplication independent with platforms.

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XML Web Services Infrastructure

XML Web services directories XML Web services discovery XML Web services description XML Web service wire formats

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Communication Between the Client and  the XML Web Service

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Creating XML Web Services

Creating an XML Web Service

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Creating an XML Web Service

<%@ WebService Language=“Language" Class=“ClassName" %>

Imports System

Imports System.Web.Services

Public Class ClassName

Inherits WebService

<WebMethod()> Public Function FunctionName() As Type

Coding here

End Function

End Class

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Creating an XML Web Service(Cont)

You can write code direct into file XML Webservice or Codebehind

Code direct:

<%@ WebService Language=“Language" Class=“ClassServiceName" %>

Code behind

<%@ WebService Language=“Language" Codebehind=“WebServiceName.asmx.vb" Class=“ProjectName.ClassWebServiceName" %>

Note: Codebehind that mean coding are written into file *.asmx.vb

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Creating an XML Web Service(Cont)

You must change:

<System.Web.Services.WebService(Namespace:=

"http://tempuri.org/ProjectName/ClassServiceName")> _

Public Class ClassServiceName

Inherits System.Web.Services.WebService Open file *.asmx -> Change Codebehind and Class properties

<%@ WebService Language=“Language" Codebehind=“WebServiceName.asmx.vb" Class=“ProjectName.ClassWebServiceName" %>

Extension file of XML Webservice is *.asmx

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Example 1

This case code are written into *.asmx fileimports Systemimports System.Web.ServicesPublic Class ClassWebServiceA inherits

System.Web.Services.WebService<WebMethod()> Public Function GetSubject() As String()

Dim ArrSubject(2) as StringArrSubject(0)="Design Web Page"ArrSubject(1)="XML Webservices"ArrSubject(2)="ASP.NET Developer"return ArrSubject

End FunctionEnd Class

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Example 2

This case code are written into *.asmx.vb fileimports Systemimports System.Web.Services<System.Web.Services.WebService(Namespace:="http://tempuri.org/PWebService/ ClassWebServiceB ")>

Public Class ClassWebServiceB inherits System.Web.Services.WebService

<WebMethod()> Public Function GetSubject() As String()Dim ArrSubject(2) as StringArrSubject(0)="Design Web Page"ArrSubject(1)="XML Webservices"ArrSubject(2)="ASP.NET Developer"return ArrSubject

End FunctionEnd Class

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Deploying and Discovering XML Web Services

Publishing an XML Web Service Items Published with a Web Service Understanding the XML Web Services Discovery Mechanism . Configuring Discovery Information for a Web Service

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Publishing an XML Web Service

We have two way deploy XML Webservice: Setup Web XML WebService Create by manual which is the same Website (Create Virtual

Directory)

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Items Published with a Web Service

The Web application directory. The <WebService>.asmx file The <WebService>.disco file The Web.config file The \Bin directory

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Understanding the XML Web Services Discovery Mechanism

The XML Web service discovery mechanism enables a client application to locate or discover the documents that describe an XML Web service. The XML Web service discovery mechanism returns a service description document to a client. The service description document is written in Web Services Description Language (WSDL) and contains information about the capabilities of an XML Web service, its location, and how to interact with it

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Consuming an XML Web Service

Consuming an XML Web Service Adding a Web Reference Generating a Proxy Class Creating an Object of the Proxy Class Accessing the Web Service Using a Proxy Object Consuming the Methods Exposed by a Web Service

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Consuming an XML Web Service

Add a Web reference to the XML Web service in the client application by discovering the XML Web service that you want to consume.

Generate a proxy class for the XML Web service. Create an object of the XML Web service proxy class in the

client application. Access the XML Web service by using a proxy object.

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Add a Web reference to the XML Web service in the client application

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WebServices on the Local Machine

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A method of XML WebService

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Generating a Proxy Class

Proxy Class is created when you press to Add reference button.

The proxy class of an XML Web service contains instructions for calling each XML Web service method .

Visual Studio .NET uses WSDL to create the proxy class . The proxy class is described in the .wsdl file.

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Creating an Object of the Proxy Class

You need to include the proxy class namespace in your client application before you can create an object of the proxy class.

You create an object of the proxy class by using the new operator

Dim objWS as new ServerName.ClassNameService

Access to Method of XML Webservice

objWS.MethodName()