Re: Prince XML vs Docbook

On Thu, 2018-01-18 at 18:15 +0000, Eliot Kimber ekimber@xxxxxxxxxxxx
wrote:
> I would disagree with your assessment that CSS pagination is not
> easier than FO *if* there was appropriate how-to guidance available.

We did a poor job (collectively) at tutorials and outreach for XML
technology, both at W3C and in the wider community, and we now pay a
price for that.

> It would also help to have a less-like facility that could be easily
> used with XSLT

It's not too hard to implement (non-cascading) CSS custom properties
("variables") in XSLT, with a simple XML document to give the values.

> Granted, working out the details of how to translate your source into
> appropriate pages is inherently challenging.

Yes - the syntax is (by and large) the easy part, although as with any
batch formatting system, getting page numbers and headers under control
can be a challenge.

> But I think CSS's way of capturing the design details as
> implementation artifacts is much more accessible to designers than
> XSL-FO page masters and page sequence masters. With some appropriate
> templating of page rules it could be pretty easy to define and
> maintain.

Yes, especially with flex and grid now in all major browsers.

> Another practical issue, and one that should not be underestimated,
> is the need to synthesize elements in source content to enable
> generation of running headers and footers (more generally, any edge
> region content). 
> 
> Because of the way CSS works you can't have an element that both
> contributes its structured content to an edge region and is shown in
> the main flow. 

This isn't entirely true, as you can use content: element(#foo) to
reuse an element, but yes, only as a string value.

> The XSLT+CSS approach separates the details of what *content* goes in
> the running heads and the styling details (where it appears on the
> page and how it's formatted in that context).
> 
> Note also that for CSS pagination to work well the input really needs
> to be HTML, not arbitrary XML. While CSS can, in theory, be applied
> to arbitrary XML, in practice it doesn't really work, for a number of
> reasons, not least of which is CSS's lack of support for namespace-
> aware selection.

CSS has namespace-aware selectors and has had for many years. It's in
CSS 2.1 iirc.

https://developer.mozilla.org/en-US/docs/Web/CSS/@namespace

You have to use | rather than colon, as CSS usd : for something else,
so you end up with
@namespace h url(http://example.org/ns/hosiery)
and then using
h|sock { color: black; }


> Leigh White's DITA for Print book serves as an excellent example of a
> comprehensive how-to guide to doing complex pagination with non-
> obvious technology from sophisticated XML source. 
Yay, and it's $165.93 on Amazon. I'll take ten... :) i found a PDF
extract, looks like it might be very interesting

> If we had a comparable book for CSS pagination I think most people
> tasked with applying CSS for pagination would be able to be
> productive with a minimum of pain.
> 
> The challenge of course is finding someone to write such a book (and
> keep it up to date as the technology evolves)....

Maybe if i retire and am independently wealthy :)

In the meantime see e.g. Rachel Andrew's book on flex and grid to get a
feel for where things might be going -
http://amzn.to/2rjY7oL [referrer link, make me rich!]

Liam

-- 
Liam Quin, W3C, http://www.w3.org/People/Quin/
Staff contact for Verifiable Claims WG, SVG WG, XQuery WG

Web slave for http://www.fromoldbooks.org/