RE: XInclude mailing list

[Forwarding message and reply to public list - seems the original never
showed up there...]

> -----Original Message-----
> From: Paul Duffin [mailto:pduffin@volantis.com]

> All,
>      I have a couple of questions on the include element.
> 
> 1) What is the purpose of allowing the include element to have
arbitrary
>     content when the XInclude processor explicitly has to ignore it ?

It is to allow annotations.  While such annotations would not appear in
the result through normal infoset properties, such annotations might be
useful to applications examining the document prior to XInclude
processing, or an XInclude processor may make these annotations
available through extended infoset properties.  For example, imagine a
"Secure XInclude" processor which annotates the xinclude element with an
XML Digital Signature.  Such a processor could not only provide an
application with a result infoset, but also with information about
whether the included resources had been changed or tampered with.

> 2) Would it be possible to make the href attribute on the include
>     element optional ?
> 
> The reason I ask is that I would like to be able to add additional
> elements to the body of the include element which would cause a
suitable
> configured XInclude processor to retrieve an XML info set from a whole
> variety of sources, not just a simple URL.
> 
> e.g.
> If an XInclude processor saw the following it would see whether it had
> been configured to handle the retrieve-from-dbms element and if so it
> would use the contents of that element to create a connection to an
> RDBMS, send it a query, create an xml info set from the result and
> insert it. If the element was not recognised, or the information could
> not be retrieved for some reason then the contents of the fallback
> element would be inserted instead.
> 
>    <include>
>      <retrieve-from-rdbms>
>        <connection-information>
>          ....
>        <query-information>
>          ....
>      <fallback>
>        Could not access the database.
> 
> Is this something which the arbitrary content within the include
element
> was intended for ?

We did not consider the scenario of extending the href attribute in this
way.  Resource locations (even databases) are usually described via URI,
which have their own structure and extensibility mechanisms.  For
instance

  <xi:include
href="database:connectivity-information?query-information">

Would these mechanisms be sufficient to your purpose?

> P.S. I have sent a note to this mailing list before but got no reply
and
> also my question did not appear in the archive but I do not know why.
If
> you are the moderator then could you please reply to this note if
there
> is a problem and possibly let me know what happened to my previous
note
> if anything.
>    Subject:   Extension mechanism for XInclude (long)
>    Date Sent: 22nd July 2002

Received on Tuesday, 17 September 2002 12:40:49 UTC