OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

wsbpel message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: Re: [wsbpel] Issue 197: Un-initializing BPEL variables


Yaron Y. Goland wrote:

> Your argument works for text nodes but not elements and who says that 
> the contents of a static value that contains nothing is a text node? 
> That certainly isn't defined in the spec today. In fact we have at 
> least 2 open issues on exactly this kind of problem.

I made no such assumption. To assign a value to a text node I need to 
obtain a string value, but if you read the XPath expression, I can 
operate on a variety of content models in order to arrive at that string 
value.

Since I consider an empty value to be a valid and useful value, we need 
a way to disambiguate between un-initializing a variable and expressions 
that can assign an empty value to a text node. Since we want to keep it 
simple, let's find an un-initializing mechanism that is not node-type 
specific, and retain that distinction across all node types.

Assaf

>
> Assaf Arkin wrote:
>
>> In XML empty is still a content. An empty text node contains zero 
>> characters. Different from nothing or null.
>>
>> For example, if I have the expression concat($X,$Y) it is valid for Y 
>> to be empty, and its reasonable for someone to set it to empty and be 
>> used. $Y needs to have a value in this case and the expression need 
>> to evaluate.
>>
>> Un-initialize will require its own construct, a) to not confuse 
>> between empty and null, and b) since we currently do not allow null 
>> to be selected.
>>
>> Assaf
>>
>> Tony Fletcher wrote:
>>
>>> This issue has been added to the wsbpel issue list with a status of 
>>> "received". The status will be changed to "open" if the TC accepts 
>>> it as identifying a bug in the spec or decides it should be accepted 
>>> specially. Otherwise it will be closed without further consideration 
>>> (but will be marked as "Revisitable")
>>>
>>> The issues list is posted as a Technical Committee document to the 
>>> OASIS WSBPEL TC pages 
>>> <http://www.oasis-open.org/apps/org/workgroup/wsbpel> on a regular 
>>> basis. The current edition, as a TC document, is the most recent 
>>> version of the document entitled in the "Issues" folder of the 
>>> WSBPEL TC document list 
>>> <http://www.oasis-open.org/apps/org/workgroup/wsbpel/documents.php> 
>>> - the next posting as a TC document will include this issue. The 
>>> list editor's working copy, which will normally include an issue 
>>> when it is announced, is available at this constant URL 
>>> <http://www.choreology.com/external/WS_BPEL_issues_list.html>.
>>>
>>>
>>> ------------------------------------------------------------------------ 
>>>
>>>
>>>
>>> Issue 197: Un-initializing BPEL variables
>>>
>>> *Status:* received
>>> *Date added:* 12 Mar 2005
>>> *Categories:* Data Handling 
>>> <http://www.choreology.com/external/WS_BPEL_issues_list.html#category_data_handling> 
>>>
>>> *Date submitted:* 11 March 2004
>>> *Submitter:* Yaron Y. Goland <mailto:ygoland@bea.com>
>>> *Description:* Is it legal/possible to un-initialize a variable in 
>>> BPEL? What happens, for example, if one tries to assign a static 
>>> from value that is empty? Should we allow for from-spec to be empty 
>>> and have that mean that the target is uninitialized?
>>> *Submitter’s proposal:* Being able to un-initialize variables is a 
>>> generically useful thing. It makes it clear when a variable doesn't 
>>> contain a 'useful' value. So I think we should provide a way to 
>>> un-initialize variables.
>>> *Changes:* 12 Mar 2005 - new issue
>>>
>>> ------------------------------------------------------------------------ 
>>>
>>> Best Regards,
>>>
>>> Tony/ /
>>>
>>> / <http://www.choreology.com/>/
>>>
>>>
>>> Tony Fletcher
>>>
>>> Technical Advisor
>>> Choreology Ltd.
>>> 68, Lombard Street, London EC3V 9L J UK
>>>
>>> Phone:
>>>
>>>
>>> +44 (0) 1473 729537
>>>
>>> Mobile:
>>>
>>>
>>> +44 (0) 7801 948219//
>>>
>>> Fax:
>>>
>>>
>>> +44 (0) 870 7390077
>>>
>>> Web:
>>>
>>>
>>> /www.choreology.com <http://www.choreology.com/>/
>>>
>>> Cohesions™
>>>
>>> Business transaction management software for application coordination
>>>
>>> Work: tony.fletcher@choreology.com
>>>
>>> Home: amfletcher@iee.org <mailto:amfletcher@iee.org>
>>>
>>
>
>

begin:vcard
fn:Assaf Arkin
n:Arkin;Assaf
org:Intalio
adr;dom:;;1000 Bridge Parkway Ste 210;Redwood City;CA;94065
email;internet:arkin@intalio.com
title:Chief Architect
tel;work:(650) 596-1800
x-mozilla-html:TRUE
url:http://www.intalio.com
version:2.1
end:vcard



[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]