SharePoint 2007: The Definitive Guide

Invoking Web Services

Calling a Web Service method is one of the best ways to learn about its behavior and data. Although some of the operations may require a fairly complex request envelope, there are plenty of tools that can make this easy. With some of the Web Services, it is also possible to invoke a Web Service directly from InfoPath, or even create an application where the user can enter data that is passed on as a request to the Web Service. The magic of InfoPath lies in its ability to work with WSDL, and its ability to automatically create and lay out form elements based on an XML schema contained in simple WSDL.

Tip

Additional Web Service tools are available for other Office applications, such as Excel and Visio. As a developer you can use Visual Studio Tools for Office, and there is also a Web Services Toolkit for Office XP and Office 2003 applications, available from Microsoft's download center.

In cases where WSDL uses more complex schemas to describe the Request and Response formats, programmers move up to more advanced tools, and eventually work with Visual Studio. Some of the Web Services, such as the Query Web Service or Site Data Web Service, utilize a lot of dynamic XML to specify parameters and then return dynamic XML based on the requested parameters.

Tip

Most of the XML structures, unless defined directly in a Web Service schema (e.g., Site Data Web Service) are documented in the WSS SDK in the Collaborative Application Markup Language Core Schemas. While making ...