Re: CSS 4?

David,

I don't see why both wouldn't continue to exist and be supported, despite
their overlap. XSL-FO describes only a layout, while CSS describes how
style should be applied to a document, which is a combination of two things.

According to me, CSS is more suitable for interactive presentation, because
it has a selector mechanism which allows straight-forward document-order
processing. This is fast. Since CSS combines selection and style, the UA
still has the document and the meaning, making interaction possible.

XSL-FO is more oriented towards paged media. The spec provides a lot of
support for paging. CSS hardly does, at least for the moment. In the printing
area this has created two cultures. Browsers, the most common CSS UAs, are
very bad at printing. They can't even cut pages properly. XSL-FO tools
are mostly very good at it. CSS itself, however, does not preclude fine
printing.

The two are perhaps growing towards each other. CSS3 provides more paging
support, while using XSL-FO interactively in a browser is just a matter of
mind set. Conceptually, browsers could provide as much functionality with
plain XSL-FO files than they can now with HTML. XSL-FO has in fact the
potential to be more performant in a browser than XHTML+CSS, because the
decision of what should applied where and in which circumstances does not
have to be taken anymore. The server has already done this. The browser
would just go over the XSL-FO tree and draw it. Expensive page cutting
algorithms are not needed because there would be only one page master of
indefinite size. Since I'm certain all this won't happen, I think CSS still
has a bright future.

In my opinion there is an area where CSS has more potential than XSL-FO:
authoring of common documents such as reports, specifications, etc. These
are documents where you don't need the finest printing features, but where
you want decent printing nevertheless. Most documents written in enterprises
are in that category. Producing XSL-FO mostly requires complex transformations,
for which XSLT is quite suitable. This is out of reach for the common author.
The styles are therefore fixed and can't be easily customised in the scope
of a particular document. XHTML+CSS, however, is just perfect for that.
The cascading mechanism provides for customisation, which can be easily
implemented in an authoring tool. CSS is a very good combination of power
and simplicity, while XHTML is a rather well known and not to complicated
language. Authoring tools could provide an intuitive interface for XHTML+CSS,
which has the technical potential of replacing the what-you-see-is-not-what-
you-want text processors we use today.

CSS and XSL-FO can also work together. The latter can be the representation
of the layout defined by applying the former to a document. In other words,
you can convert XHTML+CSS into XSL-FO.

Werner.

David Latapie wrote:
> 
> 
> 
> Hello,
> 
> Will there be such a thing as CSS4, or will the next step be an sort of 
> XHTML-compatible XSL?
> 
> Is CSS a (dead end (in the middle to long term) or is it supposed to 
> coexist wth XSL?
> 
> I don't want to start a troll, just give some pointers about that sort 
> of discussion (if any).
> 
> Thank you
> 

-- 
Werner Donné  --  Re BVBA
Engelbeekstraat 8
B-3300 Tienen
tel: (+32) 486 425803	e-mail: werner.donne@re.be

Received on Thursday, 23 October 2003 18:06:26 UTC