Colspan all columns

How can I specify a td tag should span all columns (when the exact amount of columns in the table will be variable/difficult to determine when the HTML is being rendered)? w3schools mentions you can use colspan="0", but it doesn’t say exactly what browsers support that value (IE 6 is in our list to support).

Edit: It appears that setting colspan to a value greater than the theoretical amount of columns you may have will work, but it will not work if you have table-layout set to fixed. Are there any disadvantages to using an automatic layout with a large number for colspan? Is there a more correct way of doing this?

Asked on April 7, 2016 in HTML.
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1 Answer(s)

If you’re using jQuery (or don’t mind adding it), this will get the job done better than any of these hacks.

function getMaxColCount($table) {
    var maxCol = 0;

    $table.find('tr').each(function(i,o) {
        var colCount = 0;
        $(o).find('td:not(.maxcols),th:not(.maxcols)').each(function(i,oo) {
            var cc = Number($(oo).attr('colspan'));
            if (cc) {
                colCount += cc;
            } else {
                colCount += 1;
            }
        });
        if(colCount > maxCol) { maxCol = colCount };
    });

    return maxCol;

}

To ease the implementation, I decorate any td/th I need adjusted with a class such as “maxCol” then I can do the following:

$('td.maxcols, th.maxcols').each(function(i,o) {
    $t = $($(o).parents('table')[0]); $(o).attr('colspan',  getMaxColCount($t));
});

If you find an implementation this won’t work for, don’t slam the answer, explain in comments and I’ll update if it can be covered.

Answered on April 7, 2016.
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