Structure to Style
After creating several style sheets, which create sub classes, I am
considering how associations between elements and styles work out.
If your goal is to have a document that one of several styles can be applied
to, then there must be some kind of correspondence between elements and
styles. For example, you convert a document from a book. Each chapter is a
HTML document with the title as H1, and each chapter has say three subheads
H2, H3, H4. You can then apply any one of the styles to this document by
linking. Say cyber punk or antique book. In my experience, however, this is
hard to do in practice because there are types of elements and meanings of
elements that differ based on the kind of style. For example, say you have a
book with a title and subtitle. Is the subtitle part of the title? Or is it
a separate element? We have to make the distinction between the traditional
function or meaning of a subtitle and the need to mark it for presentation
control as well as for its possible content meaning. If you want to control
the style of the subtitle you can wrap it in a <span>. But you may want to
raise to the status of an element like <subtitle> by sub classing <h1 2
Also I have trouble fixing the correspondence from traditional documents to
structured documents in HTML.
One publisher's style sheet considers the chapter number to essentially be
an element. Like this: H1: chapter number; H2: chapter title. It's necessary
to control the position of the chapter number. So it needs to be a separate
element. On the other hand I might want a running head at the top of the
page. Is this an H1? Given the meaning of heading, you could argue Hn should
not be used for a chapter number or running head.
In one of my own experiments, I wanted to use negative margins to pull the
title and subtitle together. This did not work with the subtitle section
<span> so I had to place it in <h2>. I do not know if this is a bug in MSIE
or a limitation of CSS.
I understand that HTML headings only relate to lesser of greater importance
of degree and that different documents might give those different meanings.
But it becomes more important with styles to have a standard correspondence
between elements and styles from document to document. If we could define
our own elements such as <subtitle> and <chapternumber> it would be
settled. As it is now, I have to create a correspondence between the
document headings and the heading elements that is arbitrary.
It becomes hard to predict what effect a style sheet will have on a document.
Maybe what I want is SGML...sigh.
_/ Steve Knoblock, ed., City Gallery
_/ City Gallery - History of Photography
_/ Member: National Stereoscopic Association