Ian Hickson:
> On Thu, 1 Jul 2010, Christoph Päper wrote:
Darn, my reply from yesterday got lost in data nirvana. This is a slightly
shorter version thereof.
>> So sortable tables should be marked as such.
Opt-in:
<table sortable collapsible>
“sortable=auto” should be the default and resolve to ‘sortable’ if at least one
column has a sort key assigned, and to ‘fixed’ (or the like) otherwise.
(Row and column collapsing is a related, but different beast. Let’s deal with
that separately, later.)
>> Note that ‘col’ and ‘colgroup’ elements are hardly supported.
Nevertheless, it’s usually sufficient to mark one column as containing values
to use as sort key.
<colgroup key=…>
<col key=…>
Columns inherit the key from their group, but may override it.
>> non-sortable columns inside sortable tables should be marked as such.
key=none
Not to be confused with fixed columns.
>> There are different ways to sort, eg. numeric, temporal or alphabetic
key=numeric 1 < 2 < 10
key=alpha Ä = ä = Ä (= a?), 1 < 10 < 2
key=date 2012-11-08 = 2012-W45-4
key=value 1000 g = 1 kg = 0.001 t > 1 lb
key=style although Excel can do this to some degree, it’s hardly useful
key=class slightly more useful
key=id ditto
>> and ascending or descending.
That’s better left to the UI: switch order when sorting for the second time.
>> Several columns may be used for sorting by some kind of priority.
Also primarily a UI question: use previously sorted column as secondary key.
key=1 primary key for heuristic sorting algorithm
>> The original order must be restorable.
UI again, e.g. tristate column sort: ascending, descending, original, …
>> Cells should have an optional attribute indicating their sort key.
<td value=0.454>1 lb
>> There may be columns that shall remain stable, eg. rank numbers.
key=fixed
The sorting algorithm should not work on cells, but on slots (or slot values
rather).
Cells spanning multiple rows or columns may have to be split into one cell per
slot and should be rejoined afterwards if possible. Note that ‘rowspan’ itself
is safe for vertical sorting, unless it spans a ‘fixed’ column. Also, ‘colspan‘
is safe when it appears in the column to be sorted by.
td {color: green}
[rowspan] {color: red}
<tr><td>1 <td rowspan=2>red 1 red
<tr><td>3 =sort=col1=> 2 green
<tr><td>2 <td>green 3 red
The text reads its color! A cell at (1,1) – counting starts from 0 – never
exists, the slot at the same position changes its value from ‘red’ to ‘green’.
