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Re: A List Apart: Articles: Prefix or Posthack

From: Aryeh Gregor <Simetrical+w3c@gmail.com>
Date: Fri, 9 Jul 2010 18:16:02 -0400
Message-ID: <AANLkTinCJABEFo5f_i8vZWreDprgqKQ21VW8TBjyAygq@mail.gmail.com>
To: "L. David Baron" <dbaron@dbaron.org>
Cc: www-style@w3.org
On Fri, Jul 9, 2010 at 12:02 AM, L. David Baron <dbaron@dbaron.org> wrote:
> As much as possible, we want to avoid authors putting Gecko-specific
> content on the Web.  Authors who are using -moz-box-shadow should
> also be using box-shadow; if they're not, they're writing
> Gecko-specific CSS (and perhaps some additional WebKit-specific CSS,
> etc., alongside it, which is still hostile to any new entrants in
> the browser space along with any omitted existing browsers).

On the other hand, if every -moz-box-shadow is supposed to be
accompanied by an identical box-shadow, what's the point?  A mess like
"-moz-box-shadow: foo; -webkit-box-shadow: bar; box-shadow: baz" is
only tolerable so long as foo, bar, and baz could legitimately be
different.  What you seem to be saying is that "-moz-box-shadow: foo"
should *always* be accompanied by "box-shadow: foo" in stylesheets.
Then why not drop the prefix entirely?  It adds no information to the

I thought the point of prefixes was so that we wouldn't have lots of
pages using a particular syntax before it's finalized and therefore
making it impossible to change.  But that's exactly what you propose
authors do, use the unprefixed property before it's finalized.  What's
the goal of prefixes then?  Only to signal to authors that the
property is unstable and so scare them off from using it if they
aren't willing to have their pages break, so the bad syntax isn't used
so widely and thus can be changed more easily?  Prefixes seem like a
poor means to that end -- you could do that without requiring so much

Also, what do you expect authors to write for the unprefixed property
if there are multiple conflicting syntaxes supported in different
browsers for the unprefixed property?  If I needed "-moz-box-shadow:
foo; -webkit-box-shadow: bar" to get the same effect in Mozilla and
WebKit, with foo != bar, am I supposed to do "box-shadow: foo" or
"box-shadow: bar"?  (Practically speaking, the former, since WebKit
will continue to support the prefixed version . . .)

I don't see that it's reasonable to argue that authors should use
unprefixed properties when no browser implements them, and possibly no
browser ever *will* implement them with the syntax you're using.  If
the syntax changes so that your declaration is still valid but means
something different, your page very well might render worse than if
you didn't use the property at all.
Received on Friday, 9 July 2010 22:16:36 UTC

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