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

From: Joern Turner <joern.turner@googlemail.com>
Date: Fri, 27 May 2011 21:53:45 +0200
Message-ID: <BANLkTin5CP-kN1YTO=Lk82qbhxLkwAAG9A@mail.gmail.com>
To: John Boyer <boyerj@ca.ibm.com>
Cc: "www-forms@w3.org" <www-forms@w3.org>
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 GMT

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