[xml] Question regarding Xpath and streaming

["Yong Chen \(yongche\)" <chen cisco com>]

Hi,

I've a question regarding xpath and streaming (xmlWriter):

I use xpath to filter a document so I get selected (or filtered) nodes.
I also use xmlWriter to stream output. I wonder if I can use both
together.

Libxml xpath works by first getting xmlXpathContextPtr (API:
xmlXpathNewContext(doc)), this means the document (doc) has to be
available. But if I'm streaming the data into a file
(xmlNewTextWriterFilename()), I don't have the doc available. So how can
I apply the xpath filtering in xmlWriter streaming?

Thanks,
Yong Chen