Re: XForms 1.1 Implementers encouraged to enable multiple MIP bindings per data node

Hi John,

thanks for the detailed explanation. In the light of this it makes all
perfect sense to me.

thanks,

Joern

On Fri, May 27, 2011 at 6:04 PM, John Boyer <boyerj@ca.ibm.com> wrote:
> Hi Joern,
>
> Sure.  The idea is that type is only one of a set of MIPs right now that are
> already and'd together to produce a validation result, and that trend should
> just continue.
> While it is feasible for someone to write completely incompatible types,
> it's also possible for them to write incompatible constraints, or even to
> write one required="true()" and required="false()" for the same node.
>
> The AND means that a node must be valid according to all available rules,
> and if any fail, then the node is invalid.
>
> So, in the case of type string and integer on a node containing "ABC", the
> string check passes, but the integer check then fails, so the node is
> invalid.
>
> We felt it was not a good idea to be restrictive to one type because content
> coming from multiple sources might in fact assign exactly the same type, or
> they might assign compatible derived types, i.e. one system knows more about
> what kind of type the data should take than another.  Such is the case above
> where one system only knows it needs a string, but another knows it should
> be an integer.  As soon as you start defining parts of forms that are used
> in multiple forms, it is often the case that the part will say something
> generic, and the consumer will say something compatible but more specific.
>
> Cheers,
> John M. Boyer, Ph.D.
> Distinguished Engineer, IBM Forms and Smarter Web Applications
> IBM Canada Software Lab, Victoria
> E-Mail: boyerj@ca.ibm.com
>
> Blog:
> http://www.ibm.com/developerworks/blogs/page/JohnBoyer
> Blog RSS feed:
> http://www.ibm.com/developerworks/blogs/rss/JohnBoyer?flavor=rssdw
>
>
>
>
>
> From:        Joern Turner <joern.turner@googlemail.com>
> To:        John Boyer/CanWest/IBM@IBMCA
> Cc:        "www-forms@w3.org" <www-forms@w3.org>
> Date:        05/27/2011 07:52 AM
> Subject:        Re: XForms 1.1 Implementers encouraged to enable multiple
> MIP bindings per data node
> ________________________________
>
>
> Dear Working Group,
>
> i'm considering to implement the proposal below. However i cannot make
> any sense out of the proposed AND combinator for the 'type' MIP. What
> shall be the meaning in this case? That a node e.g. can be a string
> AND an integer at the same time? I'm sure i must have misunderstood
> something here.
>
> Would be happy if you can shed some light on this.
>
> Thanks
>
> Joern Turner
>
> On Tue, Apr 13, 2010 at 7:06 PM, John Boyer <boyerj@ca.ibm.com> wrote:
>>
>> Dear Forms Community,
>>
>> It is a pleasure to inform you that the W3C Forms Working Group recently
>> decided upon a default combination mechanism for handling multiple model
>> item properties binding to the same data node. For reference, please see
>> [1,
>> 2]
>>
>> [1] http://www.w3.org/MarkUp/Forms/wiki/MIPS
>> [2] http://www.w3.org/2010/03/25-forms-minutes.html#res_multimip
>>
>> For some MIPs like calculate, more than one formula binding does not make
>> sense, so the default in that case continues to be an
>> xforms-binding-exception.  However, for other MIPs, and most notably
>> constraint, it is not only possible but also preferable to have a default
>> combinator based on the MIP.  For example, if more than one constraint MIP
>> is applied, then all constraints must be satisfied (true) for the node to
>> be
>> valid (in fact, this is consistent with current combination processing of
>> constraint, required and type MIPs anyway).  By comparison, a node would
>> be
>> readonly if any bind readonly MIP evaluates to true for the node, and this
>> is conceptually what already happens in the defaulting mechanism for
>> readonly, which makes a node readonly if any ancestor evaluates to true
>> even
>> if the readonly MIP for the node itself is false.
>>
>> For these technical reasons and also to promote faster adoption and
>> determination of any problems with the approach, the W3C Forms Working
>> Group
>> also resolved (see [3]) to encourage implementers of XForms 1.1 to proceed
>> with relaxing the xforms-binding-exception for selected MIPs and instead
>> use
>> the default combinators as described in [1].
>>
>> [3]
>>
>> http://lists.w3.org/Archives/Public/public-forms/2010Apr/att-0002/2010-04-07.html#resolution1
>>
>> Best regards,
>> John M. Boyer, Ph.D.
>> STSM, Lotus Forms
>> Workplace, Portal and Collaboration Software
>> IBM Victoria Software Lab
>> E-Mail: boyerj@ca.ibm.com
>>
>> Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer
>> Blog RSS feed:
>> http://www.ibm.com/developerworks/blogs/rss/JohnBoyer?flavor=rssdw
>>
>>
>
>

Received on Friday, 27 May 2011 19:54:13 UTC