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Re: Circular dependencies

From: Steven Pemberton <steven.pemberton@cwi.nl>
Date: Tue, 22 Nov 2016 10:51:38 +0100
To: "Erik Bruchez" <ebruchez@orbeon.com>
Cc: "public-xformsusers@w3.org" <public-xformsusers@w3.org>
Message-ID: <op.yrbpoc12smjzpq@steven-aspire-s7>
On Mon, 21 Nov 2016 19:17:12 +0100, Erik Bruchez <ebruchez@orbeon.com>  
wrote:

>> https://www.w3.org/community/xformsusers/wiki/XForms_2.0#The_xforms-recalculate_Event
>>
>> "All computes that directly refer to an instance node are its  
>> dependants; excluded are references to the current node's value in  
>> calculate >>expressions (such an instance node does not take itself as  
>> a dependent).
>>
>> A compute is computationally dependent on an instance node if there is  
>> a path of dependants leading from the instance node through zero or  
>> more >>other instance nodes to the compute.
>>
>> A compute is part of a circular dependency if it is computationally  
>> dependent on itself.
>>
>> ...
>>
>> If a compute is computationally dependent on an element in L and part  
>> of a circular dependency, then an xforms-compute-error event must be  
>> >>dispatched to the model element."
>>
>> It looks like
>>
>>        <bind ref="a" constraint=". != 13">
>>
>> is a circular dependency according to these definitions.
>
> Mmh, it says explicitly at the beginning "excluded are references to the  
> current node's value in calculate expressions (such an instance node  
> does >not take itself as a dependent)." So I guess not?

calculate != constraint

This is excluded:

    <bind ref="a" calculate="if(../condition, ., 0)"/>

Steven
Received on Tuesday, 22 November 2016 09:52:18 UTC

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