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Re: [css3-transforms] ...calcMode

From: Brian Birtles <birtles@gmail.com>
Date: Tue, 05 Jun 2012 15:12:20 +0900
Message-ID: <4FCDA344.7040806@gmail.com>
To: Dirk Schulze <dschulze@adobe.com>
CC: "public-fx@w3.org" <public-fx@w3.org>
Hi Dirk,

(2012/06/05 13:41), Dirk Schulze wrote:
> Well, the error handling is extremely tolerant in SVG. It allows
> rendering up to the point of an error. The same for animation. It
> allows starting the animation, even if there is an error on later
> values. This is more tolerant than SMIL. What do you want to relax?

Basically by not making so many things be considered errors. For
example, for both keySplines and keyTimes we have:

   If there are any errors in the ‘keyTimes’ specification (bad values,
   too many or too few values), the document fragment is in error (see
   error processing).[1]

What does "the animations shall stop at the point at which an error is
encountered"[2][3] mean here? There's no obvious way to animate up to
the error in many of these cases (and even when there is it often
equates to either animating nothing or ignoring the error). Hence why
SVG 1.2 Tiny revised this to:

   If the 'keyTimes' attribute has a value that doesn't conform to the
   above requirements the 'keyTimes' attribute has an unsupported value
   and is processed as if the attribute had not been specified.[4]

There are other cases where things could be more lenient. Trailing
semi-colons is one where we've had to revise Gecko to be more lenient
since there's content that depends on it.

I'd like to replace the catch-all "animate up to the error" with 
specific steps for each case that describe how to recover from errors.

Best regards,


[3] cf. the comment from Erik on this section who says this error
handling can be unforgiving:
[4] http://www.w3.org/TR/SVGTiny12/animate.html#KeyTimesAttribute
Received on Tuesday, 5 June 2012 06:12:53 UTC

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