Re: [xml] xpath and structured errors

[Daniel Veillard <veillard redhat com>]

On Sat, May 01, 2004 at 10:39:50PM +0200, Petr Pajas wrote:
> xmlXPathCompile(path) to compile xpath expressions. While errors like Invalid 
> expression when path="..." are reported fine, other errors like "Undefined 
> variable" (XPATH_UNDEF_VARIABLE_ERROR) when e.g. path="$xyz" and $xyz is not 
> registered, are not. Maybe it's just I'm doing something wrong. According to 

  Well the first ones are compilation errors. And the second ones are 
errors at runtime, 

> xpath.c, line 10297, the error code is assigned to ctxt->error, but it also 
> seems that it gets discarded in xmlXPathCtxtCompile at
> line 10978:
>
>     if( pctxt->error != XPATH_EXPRESSION_OK )
>     {
>         xmlXPathFreeParserContext(pctxt);
>         return (0);
>     }
>
> I'm not sure that this is intentional. Do I have to use my own 

  that's freeing of the parsing context. I don't think it relates to the
evaluation errors. The parsing context doesn't have to be kept around
for evaluations.

> xmlXPathParserContext and low-level API calls or some other way to get the 
> error, or is it simply a bug that the hi-level xmlXPathCompile function 
> doesn't also report the error via a generic structured error handler?

  xmlXPathCompile cannot report the run time error. And undefined variables
definitely sounds to me a run time error. So I think you're looking in the
wrong direction, but I may be wrong too.

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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