W3C home > Mailing lists > Public > www-style@w3.org > March 2012

Re: [css3-images] media fragments and backwards compatibility

From: Bert Bos <bert@w3.org>
Date: Wed, 7 Mar 2012 23:09:00 +0100
Message-Id: <6D5DB814-C7B6-4CFF-9193-F1137F72E331@w3.org>
To: W3C style mailing list mailing list <www-style@w3.org>

On Mar 7, 2012, at 19:13, L. David Baron wrote:

> http://dev.w3.org/csswg/css3-images/#image-fragments says:
>  # So that authors can take advantage of CSS's forwards-compatible
>  # parsing rules to provide a fallback for image slices,
>  # implementations that support the ‘image()’ notation must support
>  # the xywh=#,#,#,# form of media fragment identifiers for images.
>  # [MEDIA-FRAGS] 
> 
> First, it's not clear to me *where* this is saying that
> implementations must support fragment identifiers in images.  Is it
> saying they must support it inside of image(), or must support it in
> other places as well?  If the latter, do we know if there are
> compatibility problems?

The latter. (There is a note about that in the draft, which has become an example in the current editor's draft.)

We can just say that UAs must support the xywh form of fragment identifiers, full stop. The conditional sentence suggests that there is a choice, but, in fact, all conformant UAs must support image().


Do we want to say that, for now, the behavior of fragment identifiers is undefined for resources that aren't images or videos? The media fragments spec leaves that open. Maybe we eventually want to apply fragments to HTML documents as well.



Bert
-- 
  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos                               W3C/ERCIM
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France
Received on Wednesday, 7 March 2012 22:09:26 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 22 May 2012 03:48:51 GMT