System.Xml Document Support

The System.Xml namespace implements a variety of objects that support standards-based XML processing. The XML-specific standards facilitated by this namespace include XML 1.0, Document Type Definition (DTD) support, XML namespaces, XML schemas, XPath, XQuery, XSLT, DOM Level 1 and DOM Level 2 (Core implementations), as well as SOAP 1.1, SOAP 1.2, SOAP Contract Language, and SOAP Discovery. The System.Xml namespace exposes over 30 separate classes in order to facilitate this level of the XML standard’s compliance.

With respect to generating and navigating XML documents, there are two styles of access:

• Stream-based - System.Xml exposes a variety of classes that read XML from and write XML to a stream. This approach tends to be a fast way to consume or generate an XML document because it represents a set of serial reads or writes. The limitation of this approach is that it does not view the XML data as a document composed of tangible entities, such as nodes, elements, and attributes. An example of where a stream could be used is when receiving XML documents from a socket or a file.

• Document Object Model (DOM)-based - System.Xml exposes a set of objects that access XML documents as data. The data is accessed using entities from the XML document tree (nodes, elements, and attributes). This style of XML generation and navigation is flexible but may not yield the same performance as stream-based XML generation and navigation. DOM is an excellent technology for editing and manipulating documents. For example, the functionality exposed by DOM might make merging your checking, savings, and brokerage accounts simpler.