Rich Stephens
Software
Developer
Optio Software, Inc.
Windward Fairways II
3015 Windward
Plaza
Alpharetta, GA 30005
(770) 576-3561
[EMAIL PROTECTED]
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Tuesday, August 10, 2004 2:28 PM
To: [email protected]
Subject: RE: Xalan Xpath Caching> Hello all. I have a general question about the XPathEvaluator I have yet to find the answer to.
>
> Let's say I have a DOM like this:
...
> Now, let's say I use an XPathEvaluator. Now, I know if I use the DocumentElement of the tree as
> the ContextNode in a call to XPathEvalutor::selectNodeList(), and I want to look up the "2" under
> B, I would use an xpath _expression_ like: "B/3".
>
> Now, what if I use "B" as my Context node... do I have to take "B" into account when using an xpath
> _expression_, or do I just do "3" to get the node called "3" that is a child of "B"?
The "context node" is an XPath concept, so XPathEvaluator work with regard to the definition of the context node:
"_expression_ evaluation occurs with respect to a context. XSLT and XPointer specify how the
context is determined for XPath expressions used in XSLT and XPointer respectively. The
context consists of:
a node (the context node)
a pair of non-zero positive integers (the context position and the context size)
a set of variable bindings
a function library
the set of namespace declarations in scope for the _expression_"and, some paragraphs later:
"One important kind of _expression_ is a location path. A location path selects a set of nodes
relative to the context node. The result of evaluating an _expression_ that is a location path is
the node-set containing the nodes selected by the location path. Location paths can
recursively contain expressions that are used to filter sets of nodes. A location path matches
the production LocationPath."
Dave
