Re: Implementation issues with the VoiceXML 2.0 LCWD (20020424) XML Schemas

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----- Original Message -----
From: "Scott McGlashan" <scott.mcglashan@pipebeach.com>
To: "Dave Burke" <david.burke@voxpilot.com>; <www-voice@w3.org>
Sent: Friday, August 23, 2002 1:38 PM
Subject: RE: Implementation issues with the VoiceXML 2.0 LCWD (20020424) XML
Schemas


>
> Dave,
>
> thank you for your input. Similar problems with the schemas have already
> been reported to the group and they will be fixed in the next version. I
> will add the issues you note to our change requests.
>
> thanks
>
> Scott
>
>
>  -----Original Message-----
> From: Dave Burke [mailto:david.burke@voxpilot.com]
> Sent: Monday, August 19, 2002 22:25
> To: www-voice@w3.org
> Subject: Implementation issues with the VoiceXML 2.0 LCWD (20020424) XML
> Schemas
>
>
>
> Hi,
>
> I have recently noticed a number of issues with the XML schema strategy
> for VoiceXML 2.0 (20020424) and SRGS CR (20020626) and SSML WD
> (20020405). Obviously I have missed the LCWD call for comments by a
> considerable amount but did not notice any relevant CRs and think my
> comments could be of some benefit for a future draft.
>
> I must add the disclaimer that I only have limited Schema experience. In
> addition, I should note that the issues outlined below were provoked by
> attempting to use Java Xerces 1.4.4 (which only has beta Schema
> Recommendation support and is not necessarily a reference implementation
> - although in general I find the C++ and Java parsers excellent...).
>
>
> Hope this is of some use,
>
> Dave
>
> -----------------------------------------------------------------
> David Burke BE MEngSc
>
> Chief Architect
> Voxpilot Ltd
> Quantum House
> Temple Road
> Blackrock, Co. Dublin
>
> Mobile: +353 86 6055086
> Office: +353 1 2091922
> email: david.burke@voxpilot.com <mailto:david.burke@voxpilot.com>
> -----------------------------------------------------------------
>
> Issue 1
> =======
>
> + Synopsis:
>
> The files, grammar-adapter.xsd and synthesis-adapter.xsd, should not
> <include> the schemas they
> redefine.
>
> + Suggested solution:
>
> Remove - inclusion is implicit in the <redefine> element.
>
>
> Issue 2
> =======
>
> + Synopsis:
>
> The prefix vxml: is not required (and undefined) in grammar-adapter.xsd
> and synthesis-adapter.xsd
>
> + Suggested solution:
>
> Omit as it is implicit via the default xmlns in each of these documents.
>
>
> Issue 3
> =======
>
> + Synopsis:
>
> It *seems* the <redefine> element can only employ extension or
> restriction of base types - not both.
>
> + Suggested solution:
>
> Verify this to be true and maybe consider using a
> grammar-adapter-extension.xsd and grammar-adapter-restriction.xsd with
> vxml.xsd including the later, which in turn redefines a restiction the
> former, which in turn redefines an extension of grammar-core.xsd.
>
>
> Issue 4
> =======
>
> + Synopsis:
>
> <redefine> can only perform limited redefinition by extension or
> restriction. Specifically this
> means that omitting parent elements/attributes is not possible nor is
> loosening restrictions
> in redefined types. This affects, at least:
>
> - grammar-adapter.xsd attempt to make SRGS 'version' attribute to
> optional - not possible as it is not
> more restrictive than its base which is 'required'
>
> - synthesis-adapter.xsd attempt to use a union of types for the 'type'
> attribute of say-as - again not
> more restrictive
>
> + Suggested solution:
>
> Make base types more general - this might mean changing SRGS and SSML
> schemas.
>
>
> Issue 5
> =======
>
> + Synopsis:
>
> The grammar-adapter.xsd and synthesis-adapter.xsd files should start
> with the usual xml prolog.
>
> + Suggested solution:
>
> Add the XML prolog and use consistent encoding across all VBWG
> specifications e.g. VoiceXML 2.0 LCWD
> and SRGS CR use different encodings (UTF-8 and ISO-8859-1 respectively).
>
>
> Issue 6
> =======
>
> + Synopsis:
>
> In vxml.xsd the simpleType 'Boolean.datatype' uses enumeration with
> xsd:boolean, which is illegal.
> (ref. Section 2.1 W3C XML Schema Part 0: Primer)
>
> + Suggested solution:
>
> Use xsd:string and 'true' and 'false' enumerated values.
>
>
> Issue 7
> =======
>
> + Synopsis:
>
> In grammar-adapter.xsd 'grammar-header' and 'grammar-body' groups are
> undefined.
>
> + Suggested solution:
>
> Omit - not required if doing an <extension> or <restriction> of base
> grammar
>
>
> Issue 8
> =======
>
> + Synopsis:
>
> The <redefine> element must contain <extension> or <restriction>
> grandchildren. This is
> a problem with grammar-adapter.xsd and synthesis-adapter.xsd.
> (ref. Section 4.2.2 W3C XML Schema Part 1: Structures)
>
> + Suggested solution:
>
> Add <extension> or <restriction> as necessary.
>
>
> Issue 9
> =======
>
> + Synopsis:
>
> In vxml.xsd the anonymous complexType child of element should allow
> mixed content.
>
> Suggested solution:
>
> Add mixed="true"
>
>
>
>

Received on Tuesday, 27 August 2002 02:53:00 UTC