RE: [obix] RE: Obix question

It seems that the issue of null vs. value is (sort of) addressed in section 6.4, where the “inheritance” of the null attribute is described.  Because this talks
 about inheritance, it seems not to apply to primitives like <real>, <bool>, etc.

 

 

From:  [mailto:]
On Behalf Of Toby Considine

Sent: Thursday, March 14, 2013 1:55 PM

To: 

Subject: RE: [obix] RE: Obix question

 

Some of this could fall into the [new] conformance sections, i.e., the general rules that lie outside the individual messages.

 

tc

 

From:  [mailto:]
On Behalf Of Gemmill, Craig

Sent: Thursday, March 14, 2013 1:47 PM

To: Gemmill, Craig; Toby Considine; 'Jochen Burkhardt'; 

Subject: RE: [obix] RE: Obix question

 

Sorry for the spam, but by the way, I think the same issue applies to the example in 4.6 as well.

 

<enum range=”/enums/OffSlowFast” val=”slow”/>

 

should also have null=”false” in it.  I think these examples may have presupposed the exclusive relationship, although to my knowledge that is not formally
 expressed in the spec.  I will be sure to check though.

 

Thanks again for the comment!

Craig

 

 

From:
 [mailto:]
On Behalf Of Gemmill, Craig

Sent: Thursday, March 14, 2013 1:44 PM

To: Toby Considine; 'Jochen Burkhardt'; 


Subject: RE: [obix] RE: Obix question

 

Hi Jochen-

 

It sounds like the issue is that 4.17 states that <abstime> defaults to null, but then 4.7 supplies an example <abstime> that provides a value but does NOT
 clear the default null setting, leading to a confusing interpretation that the example has a ‘meaningful’ value but is still null.  Is that a correct interpretation?

 

As far as correcting this, my intent would be that the example in 4.7 would read:

<abstime val=”2005-03-09T13:30:00Z” null=”false”/>

 

But this begs what I have seen as a bigger question, which is about the coexistence of ‘null’ and a value.  Can an <obj> have a value and still be null?  I
 think the spec is unfortunately ambiguous on that matter.  I would like to see it clarified.  More specifically, I would like to see it clarified that having a value and being ‘null’ are exclusive conditions.  In other words, for these six object definitions,
 all of which (I think) are permitted under the 1.0 spec:

1.     
<real>

2.     
<real null=”true”/>

3.     
<real null=”false”/>

4.     
<real val=”0.0” null=”true”/>

5.     
<real val=”0.0” null=”false”/>

6.     
<real val=”0.0”/>

I would propose the following statements/clarifications.

1 and 3 are equivalent (because null defaults to false), and also an error, because an object must either have a value or be null.  2 is an example of a non-valued
 null object.  4 is an error, because an object cannot both have a value and be null.   5 is redundant, since null is by default false; it is also equivalent to 6.

 

Thanks for identifying this!

Craig

 

 

From:
 [mailto:]
On Behalf Of Toby Considine

Sent: Thursday, March 14, 2013 11:40 AM

To: 'Jochen Burkhardt'; 

Subject: [obix] RE: Obix question

 

Well, Working Draft 06 (WD06) is a working draft, so it is not surprising there are errors.

 

Comments like this should go to the TC, where they can be seen and discussed by all, and where the editor can fix them…

 

Thanks

 

tc

 

"If something is not worth doing, it`s not worth doing well "    -- Peter Drucker

Toby Considine

TC9, Inc

OASIS TC Chair: oBIX & WS-Calendar

OASIS TC Editor: EMIX, Energy Interoperation

SGIP Smart Grid Architecture Committee

  

Email:



Phone: (919)619-2104

http://www.tcnine.com

blog: http://www.NewDaedalus.com 

 

From: Jochen Burkhardt [mailto:]

Sent: Thursday, March 14, 2013 11:10 AM

To: 

Subject: Obix question

 

Hello Tony,

I have a question about the Obix spec: oBIX-1-1-spec-wd06.pdf

In chapter 4.7 there is an example for abstime:

<abstime val="2005-03-09T13:30:00Z"/>

In chapter 4.17 however:

All objects support the concept of
null. Null is the absence of a value. Null is indicated using the null
attribute with a boolean value. All objects default null to false with the exception of
enum and
abstime (since any other default would be confusing).

Would that mean the example in 4.7 is wrong or the description in chapter 4.17?

Mit freundlichen Grüßen / Kind regards

 

Jochen Burkhardt

IT Architect

IBM Software Group

Industry Software Solutions Lab Services

Phone:

+49-7031-16-3402

 IBM Deutschland

E-Mail:



 Schoenaicher Str. 220

 71032 Boeblingen

 Germany

IBM Deutschland Research & Development GmbH / Vorsitzender des Aufsichtsrats: Martina Koederitz

Geschäftsführung: Dirk Wittkopp 

Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294