W3C home > Mailing lists > Public > public-xsd-databinding@w3.org > January 2006

Re: ISSUE-7 minOccurs=0 & xsi:nil

From: <Paul.V.Biron@kp.org>
Date: Tue, 24 Jan 2006 13:24:47 -0800
To: jon.calladine@bt.com
Cc: public-xsd-databinding@w3.org, public-xsd-databinding-request@w3.org
Message-Id: <OF84A75B7B.D6B009D8-ON88257100.0074C7B9-88257100.0075A06B@KP.ORG>

> For those that haven't seen this already the recent thread (started 
> by Erik who raised this issue) on soapbuilders provides some more 
> background and discussion on this subject.
> 
> http://groups.yahoo.com/group/soapbuilders/message/10581

The update-semantics of Erik's use-case are NOT part of the XML Schema 
spec.  That is, it is completely up to the markup language designer (i.e., 
schema author) do decide what the difference between

<element>
        <child xsi:nil='true'/>
</element>

and

<element/>

is...with regard to the expected behavior in a receiver.

xsi:nil means no more nor less than what is stated in section 2.6.2 of the 
spec [1].:

        ...signaling that an element should be accepted as
        valid when it has no content despite a content
        type which does not require or even necessarily
        allow empty content. An element may be valid
        without content if it has the attribute xsi:nil
        with the value true. An element so labeled must be
        empty, but can carry attributes if permitted by
        the corresponding complex type.

So, this means that our advise to tool builders should be that they give 
users the option of specifying what xsi:nil='true' means...e.g., whether 
it has Erik's update-semantics or something else althogether.

pvb

[1] http://www.w3.org/TR/xmlschema-1/#xsi_nil
Received on Tuesday, 24 January 2006 21:26:47 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Saturday, 18 December 2010 18:20:36 GMT