Tools

Microsoft has provided some additional tools to simplify the process of consuming or building client applications for Web Services. If you are using Visual Studio .NET, some of these tools won’t be necessary to use because Visual Studio .NET has most of these command-line tools built into the IDE.

What Should I Use—WSDL.exe or SoapSuds .exe?

If you are having problems using the WSDL.exe tool to generate a proxy class for you, try using the Soapsuds.exe program. Because SOAP and remoting are basically the same thing , the Soapsuds tool also can generate the source code to communicate with the Web Service.

Soapsuds.exe

The Soapsuds tool helps you compile client applications that communicate with Web Services using a technique called remoting. Soapsuds.exe performs the following functions:

• It creates XML schemas describing services exposed in a common language runtime assembly.

• It creates runtime assemblies to access services described by XML schemas. A schema definition can be a local file, or it can be dynamically downloaded from the Internet.

WSDL.exe

The Web Services Description Language tool generates code for ASP .NET Web Services and Web Service clients from WSDL contract files, XSD schemas, and .discomap discovery documents.

Web Service Descriptor Language

The WSDL file provides you with all the necessary interface information to consume a Web Service. One problem that you might run into is that there are different versions of WSDL floating around. So far, the latest version is WSDL 1.1, but we’ll take a look here at how these differences can affect your client’s communication with the Web Service.

Many sites on the web promote Web Services, but if you try to run the WSDL.exe tool to generate a proxy stub for yourself, it might give you one of many errors. This is because there are several versions of WSDL or SDL or even SDC. The WSDL tool is designed to work with wsdl 1.1. If you try to use the WSDL.exe tool on a WSDL file and it gives you an error, that is probably because the files versions are different.

Errors While Using WSDL.exe

One of the most common problems that you might run into involves trying to generate the proxy code for a remote Web Service. Because this is an evolving technology, people are building Web Services and putting them on the web as fast as they can make them. This is great in some cases because this provides developers with many consumable resources. But, on the flip side, the technology and standards for SOAP are evolving just as fast. As soon as you get a new Web Service out there, a newer version of the standard might have been released. So now there is the issue of different formats (SDC, SDL,WSDL-1.0/1.1) floating around on the web.

Universal Discovery Descriptor Interface (UDDI)

You will start to run into the Universal Discovery Descriptor Interface (UDDI) more often. This is yet another new standard being developed for SOAP-enabled users to find and use other SOAP-enabled users—or, more likely, businesses. The best way to look at UDDI is as the Yellow Pages for Web Services.