W3C home > Mailing lists > Public > www-xml-xinclude-comments@w3.org > October 2002

Multiple root inclusions

From: Elliotte Rusty Harold <elharo@metalab.unc.edu>
Date: Tue, 8 Oct 2002 07:25:48 -0400
Message-Id: <p04330101b9c86edc314d@[192.168.254.4]>
To: www-xml-xinclude-comments@w3.org

Consider the following documents:

<?xml version="1.0"?>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
   href="http://www.w3.org/TR/#xpointer(//p)" />

<?xml version="1.0"?>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
   parse="text" href="http://www.example.com/" />

<?xml version="1.0"?>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
   parse="text" href="http://www.example.com/">
   <xi:fallback>
     <p>element 1</p>
     <p>element 2</p>
   </xi:fallback>
</xi:include>

All three seem to result in a document with multiple roots, or 
perhaps a document fragment in DOM terms rather than a full document. 
Such a thing does not have an infoset according to section 2.1 of the 
Infoset spec which states, "There is exactly one document information 
item in the information set, " and then goes to state that each 
document information item has exactly one element in its children 
property. Thus this is a qualitatively different issue than an 
unserializable synthetic infoset. A rootless or multirooted document 
is not legal as an infoset.

The XInclude processing model does not address this point. That is, 
it does not say what happens when the processing model results in an 
illegal infoset.

I suspect the attempt to create such a thing should be a fatal error. 
However, whatever the specific error (or even non-error) is chosen 
here, this possibility should be explicitly addressed in the spec. 
Users and implementers should not have to infer the meanings of these 
documents by piecing together implications in other specs.
-- 

+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+
|          XML in a  Nutshell, 2nd Edition (O'Reilly, 2002)          |
|              http://www.cafeconleche.org/books/xian2/              |
|  http://www.amazon.com/exec/obidos/ISBN%3D0596002920/cafeaulaitA/  |
+----------------------------------+---------------------------------+
|  Read Cafe au Lait for Java News:  http://www.cafeaulait.org/      |
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Received on Tuesday, 8 October 2002 07:30:25 UTC

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