Re: [xml] XPath queries on document fragments without a document

[Daniel Veillard <veillard redhat com>]

On Thu, Sep 05, 2002 at 04:27:41PM +0200, Christian Glahn wrote:
> hi all,
>
> while tracing a problem with XPath queries and document fragments I found
> that it is not possible to  XPath query an document fragment, that is 
> parsed by xmlParseBalancedChunkMemory(). this means the fragment does not
> belong to a document tree ( node->doc == NULL ).
>
> now a xpath query run through xmlXPathCompiledEval() on such a fragment will 
> allways returns nothing. apart from i think it's anoying ;) i wonder if there 
> is a reason to refuse such queries. 
[...]
> my question is now: is there a reason to refuse xpath queries on 
> document fragments?

  yes, the XPath semantic is not defined. For example what does "/"
XPath evaluation should return ???
  And an awful lot of XPath queries use / , /foo or //foo to start a lookup,
no really, having element without a document breaks an awful lot of things
in the XML infrastructure, each time I suggest not to do it, people do it
anyway and have troubles, big surprise ...

Daniel

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