22.214.171.124 Filter XPath 1.0 Subset
The filter type supports the following XPath 1.0 subset:
Node tests"*" - wildcard
<=, <, >=, >
Core Function Library: position()
The data model supported by the EventLog filter for representing XML events is a restricted form of what is used for XPath 1.0. Evaluation of each event MUST be restricted to forward-only, in-order, depth-first traversal of the XML.
The data model used differs in the following specific ways:
Because only the child and attribute axes are supported, generating a string value for nodes is not supported.
Generating an expanded name for nodes is not supported.
Evaluation of nodes in forward document order is supported, but reverse document order is not.
Node sets are not supported.
The stream of XML events is represented as the set of top-level elements in a "virtual" document. The root of this document is implied and does not have a formal name. This implies that absolute location paths are not supported. The current context node at the start/end of each XML event evaluation is this root node.
The evaluation context is a restricted version of that for XPath 1.0. It contains a current context node and a nonzero positive integer representing the current position. It does not contain the context size, nor does it contain variable bindings. It has a smaller function library, and it has no namespace scoping support.
Namespace, processing, and comment nodes are not supported.