Re: Inheritance of column attributes

   From: Hakon Lie <Hakon.Lie@sophia.inria.fr>

|    Scott Preece:
|    > My point was that what is in the draft is not acceptable.  I understand
|    > that multiple inheritance is a complication, but I think that for
|    > tables you have to do something to work around the limitations of
|    > SGML tree structure.  It is simply not acceptable to have no way to
|    > affect the styling of an entire column as a unit - changing its
|    > font-weight or background, for instance.
|   Assuming that most authors only want to hilite a column and doesn't
|   care too much about how this is done, setting the borders should be
|   sufficient.

I don't think borders alone are sufficient.  They are inherently
ambiguous and overloaded, since each border falls between two columns.
How would you, for instance, *differently* highlight two adjacent
columns?  Also, an author may want a particular style of highlighting
because that style is common in a given industry or medium.


|   Also, you can have full control, but the you need to use ID or
|   CLASS. E.g., your style sheet would look like:
|     #1a, #2a, #3a { background: blue }
|   instead of
|     COLGROUP.thisone { background: blue }

Unless I missed something, any solution using the current CSS1
specification requires that the author tag every cell in a styled
column.  This is certainly possible, but it is also error prone,
maintenance-resistant, and author-unfriendly.

|   Supporting the latter is a complication, and I don't see it being
|   superior.

Oh, come on.  As  an exercise, go create a sample table with a hundred
rows and twenty columns, with three of the columns separately
highlighted, and then tell me you still believe entering tags on 300
individual cells is not inferior to entering tags on three COLs.

|    If you still think this should be supported, could you
|   suggest a scheme for handling multiple inheritance?

I thought I had, in both previous notes: state in the standard that
for purposes of inheritance of attributes and determining context
for stylesheet-entry selection, a TH or TD is a descendant of both the
TR in which it occurs and the COLGROUP and COL defining the column in
which it occurs, with the COLGROUP and COL being considered more
specific than the TR.

Another way of saying this is that, for stylesheet purposes, the user
agent should act as though a TABLE's COLGROUP and COL elements were
replicated as elements within each TR of the table and the TH and TD
elements occurred inside the appropriate COL element.

As I've also stated before, I believe user agents already have to do
most of the necessary work of figuring out which colgroup and col a cell
is associated with, making the additional effort modest.  Perhaps one of
the browser authors would care to comment.


scott preece
motorola/mcg urbana design center	1101 e. university, urbana, il   61801
phone:	217-384-8589			  fax:	217-384-8550
internet mail:	preece@urbana.mcd.mot.com