XPath...

Whitebeam provides a comprehensive XML parsing and DOM construction facility directly accessible from JavaScript. Once a tree has been built however an application often needs to access specific parts of the tree - for example to access price information for a device. Whitebeam uses Xpath as a means of expressing sophisticated queries on the XML tree.

Searching an XML tree can obviously be achieved through recusrive functions looking for data. This is cumbersome and in practice both difficult to maintain and difficult to understand. It works - but isn't intuitive!

The W3C organisation realised this issue and developed a base technology called XPath. XPath is bascially a fairly sophisticated query language for data organised in a tree. The language allows clients to search for specific named tags - of tags that have specific named attrbutes - or attributes with specific values.

XPath is used as a base technology in standards such as XSL/XSLT and XQuery. It is however a standalone technology in it's own right - and a very powerful one!

Whitebeam integrates the XPath version 1.0 specification into it's system - making it directly and intuitively available from JavaScript. For a more complete description of how XPath is used within the Whitebeam archtitecture there is a tutorial available for those that wish to understand more fully how XPath is integrated into the Whitebeam architecture.