Re: IDs vs. Classes

 From: Bert Bos <bbos@mygale.inria.fr>
| Scott E. Preece writes:
| It's not very readable anymore, but I agree that some form of logical
| connectors might be useful. Especially the &, since it is not
| expressible in any other way. How about
|     <P class="abstract,rationale">
|     P.abstract.rationale
| (for CSS *after* level 1, of course.) This is a simple and readable
| notation for the &-case. For the or-case we might be able to find
| something with a comma.

That would be fine, too.  My primary concern is just that the spec make
it clear and that it not be confusing (e.g., using "+" for AND would be
confusing because some logic notations use it for OR).

|  > 2) My more serious concern is that Cougar has mis-specified the CLASS
|  > attribute.  It says it's a comma-separated list of classes, but both the
|  > standards (i18n and tables) that include CLASS say it's a
|  > space-separated list of classes.  This needs to be fixed in Cougar
|  > before people go off and implement it.
| Actually, I think the comma is better, since it allows spaces in class
| names. Cougar should explain that class names are separated by commas
| and also `normalized', i.e., trailing whitespace is removed, all
| sequences of whitespace are replaced by single spaces, and all letters
| are case-insensitive.

Aren't spaces in class names ruled out by their being defined to be SGML

But the issue here is that the RFCs are the closest things we have to
genuine, open-systems standards for HTML, and it looks really bad for
W3C to act as though it can "improve" them at will.

|  > Again, there are two possible meanings of having multiple values.  It
|  > would make prefectly good sense to OR together IDs, but, as you note,
|  > not to AND them.
| SGML doesn't allow multiple IDs on an element, so, unlike CLASS, there
| is no need for logical connectors on IDs.

As I said, multiple IDs only make sense for the OR interpretation, as
a notational convenience


is more convenient than

	P.p177 P.p123 P.p197 P.p224

and arguably faster to parse.


scott preece
motorola/mcg urbana design center	1101 e. university, urbana, il   61801
phone:	217-384-8589			  fax:	217-384-8550
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