prevent emty class attribute added to each cell ( class=" " )

hirnsaege

Dear supporters,
i'm trying to clean up a large data table as much as possible to improve loading and processing performance.
besides the usual optimizations, i also try to clean up the source DOM as much as possible, that is removing unneeded classes etc.
after i have removed almost all classes, i see that datatables adds an emty class attribute to each cell.

So my original DOM is: foo
and datatables processes and creates: foo

I'm wondering if this is any purpose, and if not, if i could prevent doing it, as i think adding lets say 1000x20 attributes to the DOM may take some time in slower browsers ...

I have searched the documentation, but could not find anything about cell classes, only about row classes so far.

thanks for your help
hirnsaege

allan

Heh - oddly, the empty space class names are due to a performance optimisation for the sorting classes. Its much faster to do it the way DataTables does, although less clean, rather than using hasClass etc. Its a trade off between performance and cleanness. If you want to change it, have a look at the _fnSortingClasses method.

Allan

hirnsaege

thanks for the reply – if it serves overall performance, i'm just happy with it.
i was just wondering whether adding the (from my perspective useless) empty class while initializing would cause a delay before the table is "usable", but if it has a purpose, it's okay to me.

just thinking: would it potentially speed up things if i add the class=" " when creating the table at the server, so datatables does not have to do that job?

allan

It should only add it to cells which have been sorted in a column. It won't just add it to all cells - as you say, that owl due a performance hit.

Allan

hirnsaege

okay, that's strange – according to firebug, it adds class=" " to every td in the table, if the td does not have a class="foo" set in the original data. (if so, it changes it to class="foo ") though.

this is my configuration at the moment:
[code]
var oTablename = $('#tablename').dataTable( {
"bPaginate": false,
"bLengthChange": false,
"bStateSave": true,
"iCookieDuration": 120,
"bProcessing": true,
"bSortClasses": false,
"bAutoWidth": false,
"aoColumns": [
{"sWidth": "25%", "bSearchable": false, "bSortable": true},
{"sWidth": "25%", "bSearchable": false, "bSortable": false},
{"sWidth": "25%", "bSearchable": true, "bSortable": true},
{"sWidth": "25%", "bSearchable": false, "bSortable": false},
],
"asStripeClasses": [ ]
}
} );
[/code]

i have set bSortClasses to false. this way, every td in the table has a class=" " added with initialisation.
If i set it to true, it every tdhas the class=" " after initialization, and then adds the classes class="sorting_1 " ... to the column cells when they are sorted (as you say), while the rest of the columns (not specifically sorted) is still class=" ".

sorry if leading you in circles with this ... i'm even not sure if it's a problem at all.

kind regards
hirnsaege

allan

You are right - there is something odd going on there. I wonder if there is a regression in 1.9.4 :-(. Unfortunately I'm away for a few days traveling, but I'll look at this when I get back and determine exactly what is going on.

Thanks for flagging this up.

Allan

hirnsaege

thanks for looking into it – no problem if this takes a while ... my IE8 users are used to wait :-)

hirnsaege

anything new in this yet? (no hurry, just interest)

allan

Not yet sorry. I'll be looking at this as part of the 1.10 development, but that's on hold while I work on some contracts. Hope to get to it at the end of the month.

Allan

DutchSpeed

I'm having the same problem.

Is there any fix yet?

Thanks in advance.

allan

Not yet. Still on the to-do list.

Allan