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



On Thu, Sep 05, 2002 at 12:15:09PM -0700, Sean Chittenden wrote:
[...]  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 ...

Return NULL on all queries that start with / and node->doc == NULL?  -sc

  foo[ id = /bar/value]

  and this breaks.

THE SOLUTION, is to keep a surrounding document element, as well as
a fake root element to encapsulate the well-balanced chunk and run the
query on this perfectly well defined document. 

A document fragment ain't an XML document. Make it a document and
everything becomes smooth,

Daniel

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