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Re: [SVGMobile12] SVGT12-207: Conflicting requirements in 5.9.3 The 'prefetch' element

From: Ian Hickson <ian@hixie.ch>
Date: Wed, 28 Dec 2005 14:40:31 +0000 (UTC)
To: Chris Lilley <chris@w3.org>
Cc: www-svg@w3.org
Message-ID: <Pine.LNX.4.62.0512281437220.7669@dhalsim.dreamhost.com>

On Tue, 20 Dec 2005, Chris Lilley wrote:
> >
> > In section 5.9.3 The 'prefetch' element, the various attributes seem 
> > to conflict with each other. For instance, if mediaSize="1024" is set 
> > on a <prefetch> element, but mediaTime="" is not, it means (according 
> > to the current text) that the first kilobyte should be fetched, _and_ 
> > that the entire media should be fetched.
> Yes, you are right. 'mediaSize' and 'mediaTime' should be treated as a 
> pair. We have corrected this as follows:
> For 'mediaSize' and 'mediaTime', we removed the sentence
>   If the attribute is not specified, the behavior is that the entire
>   media should be fetched.
> and we have changed the paragraph below the attribute definitions to say
>   When 'prefetch' refers to external media, if both 'mediaSize' and
>   'mediaTime' are specified, then 'mediaSize' is used and 'mediaTime' is
>   ignored. If neither 'mediaSize' nor 'mediaTime' is specified, the
>   behavior is that the entire media should be fetched.
> This covers all four cases (where each of mediaSize and mediaTime are
> specified or not specified).

While this is a distinct improvement, the phrasing suggested above still 
lacks conformance criteria for the case where both attributes are 
specified. The phraseology "is used" does not, per the definitions in your 
conformance chapter, place any conformance restrictions on user agents. 
This is especially relevant since there is no clear normative definition 
in this section regarding what using these attributes actually means.

Please correct the specification to specify exactly what the requirements 
on user agents should be when handling the <prefetch> element.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Wednesday, 28 December 2005 14:40:52 UTC

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