FW: [xliff-comment] Schema issues with extensible attributes

From
Tony Jewtushenko <>
Date
2006-10-20T18:41:36+00:00
ID
00d701c6f477$63081f00$1400a8c0@piltjlap
Thread
FW: [xliff-comment] Schema issues with extensible attributes
-----Original Message-----

From: Tony Jewtushenko
[mailto:] 

Sent: 20
 October 2006 19:39

To: 'Doug Domeny'

Cc: 'Rodolfo M. Raya';
''; 'Asgeir Frimannsson'

Subject: RE: [xliff-comment]
Schema issues with extensible attributes

 

All: 

 

What is the opinion of the TC on the
“lax” vs. “skip” processing issue?   Until
there is some feedback from the TC I will hold off on balloting… If
we’re satisfied with using “skip” I can bundle the schemas
& sample docs together with the spec and set up a ballot.  In this
case I would have to revise the spec section on using the XSD’s to
indicate that external schemas are ignored when validating with the
transitional XSD.

 

If we need further investigation &
discussion it’s worth holding off until we come to a clear
consensus.  Either way, please make your views known.

 

Regards,

Tony

 

-----Original
Message-----

From: Asgeir Frimannsson
[mailto:] 

Sent: 20
 October 2006 01:35

To: Doug Domeny

Cc: Tony Jewtushenko; Rodolfo M.
Raya; 

Subject: Re: [xliff-comment]
Schema issues with extensible attributes

 

Doug,
all,

Thank you for the detailed explanations of the XML schema issues, especially
for the clarification on meaning of use='prohibited' . 

I am a slightly concerned with changing processContent from 'lax' to 'skip', as
this will not allow us to validate foreign elements/attributes easily. I was
not able to reproduce this bug in xsv (same version as you) or .NET ( 2.0), and
I was not able to find a report or reference to this bug on msdn or google. Can
you share some more information on this? 

(after some further testing) It seems that the xsv validator attempts to
resolve the schema location from the namespace name if no schemalocation is
set, ( e.g. if your namespace is http://example.com/example
it will try and load the schema from this location, or if filename-like it will
try and load it as a relative url/file). It is important to note however that
while this is reported in the validator output, it is NOT a validation problem,
as the schema is still reported as valid. If set to 'strict' however, the
missing schema is reported as a validation error, as expected. 

cheers,

asgeir

On 10/19/06, Doug Domeny <>
wrote:

Asgeir,
XLIFF TC,

Thanks for pointing out these issues.

Attached are the modified schemas and Sample_AlmostEverything* files. Note

that the files are appended with today's date so that they do not

accidentally overwrite the official copies. Just rename them to remove the 

date from the file name.

Asgeir, please test them using your validator(s).

Here's a summary of the changes:

1. Sample_AlmostEverything_1.2_transitional.xlf

1.1 Fixed the file name of the schema by removing the date as pointed out by 

Asgeir.

2. Sample_AlmostEverything_1.2_strict.xlf

2.1 Fixed the file name of the schema by removing the date as pointed out by

Asgeir.

2.2 Remove deprecated attributes.

3. xliff-core-1.2-transitional.xsd 

3.1 processContents="skip" (was "lax")

The value "lax" is the correct value except that two of the
validators (.NET

XML Parser and XSV 2.10-1) complain that they cannot read the schema. In 

short, they treat "lax" the same as "strict". Although I
consider these bugs

in the parsers, it seems better to use "skip" so that all the parsers
I have

(see list below) succeed. Besides, the validation is slightly faster because 

it does not need to check for a schema. The only downside is that if a

schema is available for the 'other' namespace, it will be ignored.

3.2 Removed occurrence from xsd:sequence for 'tool' element.

<xsd:element name="tool"> 

        <xsd:complexType
mixed="true">

                <xsd:sequence
maxOccurs="unbounded" minOccurs="0">

                        <xsd:any
maxOccurs="unbounded" minOccurs="0" ... 

is now

<xsd:element name="tool">

        <xsd:complexType
mixed="true">

                <xsd:sequence>

                        <xsd:any
maxOccurs="unbounded" minOccurs="0" ... 

Only one of the validators (Xerces or XSV) complained about the (potential)

ambiguity.

4. xliff-core-1.2-strict.xsd

Same changes as in transitional, plus:

4.1 Removed deprecated attributes. They previously were declared with 

use="prohibited".

The use="prohibited" attribute is a bit confusing. As it turns out,
the

standard states that use="prohibited" is only useful when a
definition

inherits from a base definition, such as when adding a restriction. In this 

situation, the use="prohibited" may be used to make an optional
attribute in

the base definition invalid. In other words, as if it was not defined. It is

not to be used to explicitly prohibit attributes in a type that allows 

xsd:anyAttribute. Oh, well. The validators, however, are not consistent. The

Stylus Studio 2006 and MSXML 4.0 parsers interpret use="prohibit" to
mean

the attribute is invalid. The newer parsers follow the standard and complain 

if use="prohibit" is used when there is no base definition. OK, so to
comply

with the standard and newer parsers, we can't define deprecated attributes

with use="prohibited", we must simply not define them and hope the
parser 

will treat them as invalid.

4.2 Changed namespace from ##any to ##other to invalidate deprecated

attributes.

<xsd:anyAttribute namespace="##any"

to

<xsd:anyAttribute namespace="##other" 

The other half of this change is the namespace for anyAttribute. As Tony

pointed out, the TC chose '##any' to support backward and forward

compatibility. However, W3C XML Schema does not provide a way to override 

anyAttribute and explicitly prohibit deprecated attributes, so the namespace

'##other' is needed, as Rodolfo suggested. Since this is only for the

'strict' edition of the XLIFF schema, it should be acceptable.

List of validators I have:

Stylus Studio 2006 built-in

MSXML 4.0 DOM Parser

MSXML 6.0 DOM Parser

Saxonica 8.7 Validator

.NET XML Parser (probably .NET 1.0, but I'm not sure)

Xerces-J 2.5.1

XSV 2.10-1

Regards,

Doug Domeny

Software Analyst

Ektron, Inc.

+1 603 594-0249 x212

http://www.ektron.com

-----Original Message-----

From: Asgeir Frimannsson [mailto: ]

Sent: Tuesday, October 17, 2006 8:13 PM

To: 

Subject: [xliff-comment] Schema issues with extensible attributes 

Hi all,

I just noticed that the deprecated attributes from 1.1 (eg. ts, tool) are

still being accepted in 1.2 using the strict schema. They are defined with

use="prohibited" in the strict schema. A good example of this is the
example 

XLIFF file provided with the specification

(Sample_AlmostEverything_1.2_strict.xlf) - the file still includes all

prohibited attributes, and validates fine with schema validators.

At first I thought this was a bug in the validator I'm using, but then i 

noticed how the attribute extension points are defined in the XLIFF schema

(transitional and strict):

      <xsd:anyAttribute
namespace="##any" processContents="lax"/>

The XLIFF specification states that "Attributes of a namespace different 

than XLIFF can be included in several XLIFF elements". The schema allows
for

attributes of any namespace to be included, including xliff-namespace

attributes not defined in the specification. The schema and specification 

are inconsistent here, and it seems the right thing to do would be to change

all anyAttribute elements to:

      <xsd:anyAttribute
namespace="##other" processContents="lax"/>

In addition, some issues with the strict sample XLIFF file provided with the

specification:

- schemaLocation points to xliff-core-1.2-strict-20060512.xsd (should point

to xliff-core-1.2-strict.xsd)

- As noted, It still includes the prohibited attributes (eg. tool, ts) 

And similar with the transitional sample XLIFF file:

- schemaLocation points to xliff-core-1.2-transitional-20060512.xsd (should

point to xliff-core-1.2-transitional.xsd)

cheers,

asgeir

--

Asgeir Frimannsson

PhD Candidate

  School of Software Engineering and Data Communications

  Queensland University of Technology

  126 Margaret Street, Level 3

  Brisbane QLD 4001, Australia

Phone: (+61) 7 3138 9332 Mob: (+61) 405 412 696 

Email: 

-- 

Asgeir Frimannsson

PhD Candidate

School of Software Engineering and Data Communications 

  Queensland University of Technology

  126 Margaret Street, Level 3

  Brisbane QLD 4001, Australia

Phone: (+61) 7 3138 9332 Mob: (+61) 405 412 696

Email: