Re: [xml] XPath context

[Daniel Veillard <veillard redhat com>]

On Fri, Apr 20, 2001 at 01:12:27PM -0400, carl douglas convergys com wrote:
> Hi,
>
> Would someone mind explaining to me what effect setting
> the node member in a xmlXPathContext structure has on
> an X Path evaluation.
>
> for example,
>
> ctxt = xmlXPathNewContextPtr(doc);
> ctxt->node = xmlDocGetRootElement(doc);
>
> result = xmlXPathEval( BAD_CAST"/book/chapter[1]/descendant::*", ctxt");

  won't change anything for this XPath expression but is very
important when you do a relative path query like:

  "chapter[1]/descendant::*"

 if you're placed at the root would will have a different answer as
if placed at /book

  You can play with relative and absolut XPath queries when using
xmllint --shell yourfile

  the cd/ls/etc... commands uses a XPath expressions to locate their
target nodes.

Daniel

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