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Re: ACTION-2211: Redefine terms via xdm instead of xpath[1, 2]

From: Steven Pemberton <steven.pemberton@cwi.nl>
Date: Wed, 06 Feb 2019 11:34:09 +0100
To: "Erik Bruchez" <ebruchez@orbeon.com>
Cc: XForms <public-xformsusers@w3.org>, "XForms Users Community Group Issue Tracker" <sysbot+tracker@w3.org>
Message-ID: <op.zwscatzbsmjzpq@steven-xps>
OK, how about:

"Types in XForms are principally used to check the validity of strings  
provided as values to nodes.

However, these types can also be used by the expression language when  
evaluating expressions using nodes; the XForms processor should therefore  
provide the typed values of nodes to the expression evaluator, and not  
just the strings.

If the evaluation of an expression fails because of a type error:
  * for a calculate expression, the result is the empty sequence;
  * for a constraint expression, the result is false();
  * for other bind computed expressions, the result is not applied to the
  node;
  * for all other expressions, an xforms-expression-error event is
  dispatched to the element containing the expression."

Steven

On Wed, 06 Feb 2019 07:32:23 +0100, Erik Bruchez <ebruchez@orbeon.com>  
wrote:

> This is my response to "ACTION-2216: XForms: Erik to review 2nd part and  
> see >if Steven's understnding is right, if there is too much text in the  
> spec".
>
>> The other is section 6.2 Typed Values
>> https://www.w3.org/community/xformsusers/wiki/XForms_2.0#Typed_Values
>> which I now realise I don't understand the purpose of entirely.
>>
>> I think the argument is
>>
>> "Types in XForms are principally used to check the validity of strings  
>> provided as values to nodes. However, the expression language may also  
>> use those types during the evaluation of expressions using those nodes.
>>
>> If the evaluation of an expression fails because of a type error:
>> * for a calculate expression, the result is the empty sequence
>> * for a constraint expression, the result is false()
>> * for other bind computed expressions, the result is not applied to the  
>> node
>> * for all other expressions, an xforms-expression-error event is  
>> dispatched to the element containing the expression."
>>
>> Do you think there is any other part of that section that is normative  
>> that I have missed?
>
> I don' think that's quite enough. We should also tell how "the  
> expression >language may also use those types during the evaluation of  
> expressions using >those nodes" in case there is not a type error.  
> Mainly, this means that with >XPath 2, the processor must expose the  
> typed values of nodes when nodes are >atomized or accessed with the  
> `data()` function.
>
> -Erik
Received on Wednesday, 6 February 2019 10:36:31 UTC

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