Examples for Proposed Single-pass Extension Validation

[Kenneth Vaughn <kvaughn@trevilon.com>]

Per my task from the last teleconference, I have created an example of  
what my proposal would look like for handling extensions in a single  
pass. The easiest way to demonstrate this is to unzip the contents of  
the attached file into your UBL PRD1 directory. You can then modify  
the "include" element in UBL-CommonExtensionComponents-2.1.xsd to  
point to either UBL-ExtensionContentDataType-2.1.klv.xsd or UBL- 
ExtensionContentDataType-2.1.klv-cust.xsd. The files should then be  
good to play with (with one note below). Descriptions for each file are:

UBL-ExtensionContentDataType-2.1.klv.xsd
This is the proposed STANDARD schema file that would be distributed.  
It defines the ExtensionContentType datatype and references the  
digital signature namespace. (Obviously, the namespace reference would  
be removed, if we moved signatures into the main body). If you  
evaluate Example-Invoice-2.1.klv.xml with the  
CommonExtensionComponents-2.1.xsd including this file, it will pass  
validation, but none of the extensions will be checked as the  
namespaces will not be recognized by the validator; instead, the  
extensions are simply skipped.


UBL-ExtensionContentDataType-2.1.klv-cust.xsd
This is an example customization of the standard file above. An  
implementor would customize the file to
1) define the customization namespaces that the implementation can  
recognize and
2) import the customization schemas containing the specific elements  
that can be included as extensions
That is the only customization needed; and technically, the namespaces  
do not need to be declared since they are not actually referenced in  
the schema; they are only provided for readability. If you evaluate  
Example-Invoice-2.1.klv.xml with the CommonExtensionComponents-2.1.xsd  
including this file, the content of the defined CorpX and RegionY  
extensions will be checked - this can be shown by playing with the  
values in the example XML document as described in the comments  
embedded within the file.


CorpX.xsd
An example of a schema containing a customized extension.


RegionY.xsd
A second example of a schema containing a customized extension; the  
second example demonstrates that a single instance file can reference  
multiple custom extensions and they are all validated in a single pass.


Example-Invoice-2.1.klv.xml
The example XML document to play around with. As is, it should  
validate with either Extension Content Data Type schema; but if you  
change the extension content when using the customized Extension  
Content Data Type schema, errors will be flagged.  The example also  
includes an extension from a third (undefined) namespace to  
demonstrate that this extension will be skipped over while still  
validating the recognized extensions.




===========     NOTE    NOTE    NOTE   ===================

As near as I can tell, it SHOULD work as described above. For some
reason, XMLSpy would not check the content of the Extensions as
these files are written... I had to change the namespace for the UBL
Invoice schema in both the XML instance document and the UBL
Invoice schema for it to work as described. I spent about 3 hours
trying to figure out why it was not checking the content only to
stumble upon this work-around. It works if I simply change the
namespace (i.e., the full URN) to have a 3 at the end instead of a 2...

I can not figure out why this would be a problem, my working theory
is that it is some bug within XMLSpy itself (perhaps it is stuck on the
old definition of the namespace referring to the old Extension??? But
I rebooted my machine and still had the problem...). In short, I was
unable to think of any reason that the namespace would pose a real
problem and I am suspecting that it is unique to XMLSpy (older
version) and/or my machine - but if you do not see it checking content
when it should, please let me know and perhaps we can figure out
why this anomaly occurred.

Actually, if it does work for you, I'd be interested in knowing as well
and what software you are using... 3 hours is too much time to spend
chasing down a fake problem!

====================================================

The attached file is in zip format

KLV UBL Extensions Example.zzz.zip

Regards,
Ken Vaughn
Trevilon Corporation
12906 Pinecrest Rd
Herndon, VA 20171
+1-703-390-1053
+1-571-331-5670 cell
www.trevilon.com