There are two major types of application programming interfaces (APIs) that can be used to parse XML:
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Tree-based APIs map the XML document to a tree structure. The major tree-based API is the Document Object Model (DOM) maintained by W3C. A DOM parser is particularly useful if you are working with a deeply-nested document that must be traversed multiple times.
For more information about the DOM parser, see the W3C Document Object Model page at http://www.w3c.org/DOM.
PowerBuilder provides the PowerBuilder Document Object Model (PBDOM) extension to enable you to manipulate complex XML documents. For more information about PBDOM, see the section called “Using PowerBuilder XML Services” in Application Techniques and PowerBuilder Document Object Model in PowerBuilder Extension Reference.
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Event-based APIs use callbacks to report events, such as the start and end of elements, to the calling application, and the application handles those events. These APIs provide faster, lower-level access to the XML and are most efficient when extracting data from an XML document in a single traversal.
For more information about the best-known event-driven parser, SAX (Simple API for XML), see the SAX page at http://sax.sourceforge.net/.
Xerces parser
PowerBuilder includes software developed by the Apache Software Foundation (http://www.apache.org/). The XML services for DataWindow objects are built on the Apache Xerces-C++ parser, which conforms to both DOM and SAX specifications and is portable across Windows and UNIX platforms. For more information about SAX, see the Xerces C++ Parser page at http://xerces.apache.org/xerces-c/index.html.
