Re: [xml] Obtaining xpath expression original value

[Daniel Veillard <veillard redhat com>]

On Fri, Apr 16, 2004 at 11:14:29AM -0400, Agustín Villena wrote:
> Hi!
>     I'm using libxml2.6.2, Nad I'm working in a framework to easily program xslt extensions in c++.
>
> I'm trying to report if an argument is invalid (for example, if an xpath expression returns a invalid type 
> of argumnet, i.e. expecting one string and receiving a subtree). Obtaining the original xpath expresion 
> would be great
> (for example: "/root/tree/firstnode is not of type boolean")(
>
> void xslFunctionCallback(xmlXPathParserContextPtr ctxt, int nargs)
>
> in libxml source code, two fields of xmlXPathParserContext struct would have this info
> const xmlChar *cur;   /* the current char being parsed */
> const xmlChar *base;   /* the full expression */
>
> Nevertheless, cur and base are always NULL...
>
> I'm missing something important?

  Confusing... The XPath expression you're trying to examine comes from the
stylesheet or is it something you dynamically compiled ?
  In the first case you can't find errors, if there is an error the stylesheet
compilation will fail. You will get the element, andf you can lookup
the attribute hosting the expression. 
  In the second case look at testXPath.c from the distribution it does
this kind of error reporting.

Daniel

-- 
Daniel Veillard      | Red Hat Desktop team http://redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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