Find matching nodes in an internal XML tree/DOM

DESCRIPTION:

This function provides a way to find XML nodes that match a particular criterion. It uses the XPath syntax and allows quite powerful expressions for identifying nodes. The XPath language requires some knowledge, but tutorials are available. Uses the libxml routine xmlXPathEval. NOTE: Not currently working in S-Plus -- this function only works with "Internal Document" objects, which are not currently implemented.

USAGE:

getNodeSet(doc, path, namespaces = character())

ARGUMENTS:

doc
an object of class XMLInternalDocument to process.
path
a string (character vector of length 1) giving the XPath expression to evaluate.
namespaces
a named character vector giving the name-URI pairs for the namespaces of interest in the XPath query.

VALUE:

The result of the libxml routine xmlXPathEval, converted to an S-Plus object.

AUTHOR(S):

Duncan Temple Lang

REFERENCES:

http://xmlsoft.org, http://www.w3.org/xml, http://www.w3.org/TR/xpath, http://www.omegahat.org/RSXML

SEE ALSO:

EXAMPLES:

# NOTE: THIS WILL NOT CURRENTLY WORK, SEE ABOVE
  fileName <- system.file("exampleData", "mtcars.xml", package ="XML")
  doc < xmlTreeParse(fileName, useInternalNodes = TRUE )
  getNodeSet(doc, "/dataset")