XPathTransformer with Xalan-C

[Peter Murphy <pe...@fast.fujitsu.com.au>]

All,

Some people referred to Xalan-J's XPathAPI on this list. Currently, there is
no Xalan-C equivalent. "Fine", I thought, "I'll roll my own". So at the
moment, I'm working on a class called XPathTransformer - analogous to the
XalanTransformer class existing in Xalan-C 1.1. There are two reasons I'm
doing this:

(a) It will help me understand the XPath classes in Xalan-C.
(b) I though to be a useful feature for Xalan newbies.

Once I'd finished with them, I'd submit these patches to the list. But
before I do, there are several questions I have:

1. Would this patch be seen as a useful feature in Xalan-C?

2. Is there anyone else working on the same thing?

3. Should the capabilities in the XPathTransformer be independent of
XalanTransformer. For the time being, I'm designing it as a seperate class.
However, there are advantages to integrating both together:

(a) Repetition of support objects.
(b) The XalanTransformer::initialise() and terminate() repspectively
allocates and deallocates an XSLTInit object. In the XPathTransformer, the
analogous routine does the same with an XPathInit object. But it might cause
problems to use both classes together in the same routine.

4. I'm a little bit uncertain as to how make a C API for XPath objects -
probably because I haven't seen any attempts in doing a C API for XalanNode,
XalanNodeList, etc. Has anyone attempted this?

Anyway, I thought I'd make some comments, and see what people think.

Regards,
eter