XPATH path expressions are used to refer to specific nodes or values in an XML document.
The XPATH expression syntax appears much like a file system path to address the hierarchical nature of an XML document.
The following are common path expressions to use:
|nodename||Selects a node and all of its children|
|/||Selects the document root|
|//||Selects a node and all of its children; regardless of where it is located in the XML document hierarchy.|
The use of this path expression can kill performance in large documents – the parser looks at every node. Give the parser some hints by narrowing the search; try to use specific paths or wildcards.
|.||Selects the current node|
|..||Selects the parent node in relation to the current node.|
|@||Selects an attribute|
Combining path expressions with wildcards and XPATH functions offers a robust method to reference nodes/values in an XML document.
The following examples shows how to use the path expressions in a meaningful way: