Chapter 5. Processing XML

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XML is one of the key technologies underpinning the Microsoft .NET Framework. In fact, XML is a significant feature in almost all recent environments and frameworks, including later versions of Java 2 Enterprise Edition (J2EE). Due to its flexibility, XML is applied in many ways and at many levels. At higher levels, business data can be represented in an XML format, as can business concepts such as workflows between organizations. At lower levels, XML can be used as a convenient format for application configuration information and component metadata. Also, XML provides the packaging and structure that make Web services possible. It's no surprise, then, that the processing and manipulation of XML is well supported within the .NET Framework.

As an application developer, you'll encounter XML in many places. Components used by your application might generate XML documents that your application will then need to process and from which you will need to extract information. Conversely, your applications and components might themselves generate data in XML format to exchange it with other systems or store it.

The type of processing required and the source (or destination) of the XML to be processed will vary based on the context of your application. To help you address these scenarios, you need a set of tools and libraries that provide different ways to manipulate XML. The .NET Framework and Microsoft Visual Studio .NET provide such tools and libraries. These include GUI tools for designing and manipulating XML, XML parsers and processors, and APIs that let you create, access, and manipulate data in XML format. You can choose from a range of facilities, ranging from low-level manipulation of XML documents to transformation of XML data using a stylesheet to sophisticated binding between XML and ADO.NET DataSet objects. These tools allow you to apply the right level of functionality to address your requirements.

This chapter will examine the XML support available to J# developers through Visual Studio .NET and the .NET Framework. It will look at how you can use XML as a convenient format for platform-independent and cross-language documents and how applications can produce and consume valid XML. It will also examine the relationship between XML and relational data as typically stored in databases.

Note

The transformation of XML documents using XML Stylesheet Language for Transformations (XSLT) and the navigation of XML documents using XPath syntax is described in Chapter 6.

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