jQuery sortColumns plugin: How to sort correctly with rowspan

Question

Following this post jQuery table sort (github link: https://github.com/padolsey/jQuery-Plugins/blob/master/sortElements/jquery.sortElements.js), I am successfully sort columns,

Answer 1

Considering question 1, try this code:

var inverse = false;
var curRowSpan = 0;
var curIndex = 0;
var doRowSpan = false;
function sortColumn(index){
    index = index + 1;
    var table = jQuery('#resultsTable');
    table.find('td').filter(function() {
        var result = false;
        // if it is a column before the sorting column, watch the rowSpan
        if (curRowSpan == 0 && jQuery(this).index() < index && jQuery(this).attr("rowspan") > 1) {
            curRowSpan = jQuery(this).attr("rowspan");
            doRowSpan = true;
            // we are not in the sorting column so we can safely continue
            continue;
        }

        if(!doRowSpan) curIndex = index - (curRowSpan?1:0);
        else curIndex = index;

        if(jQuery(this).index() == curIndex) {
            // we are at the sorting column
            if(curRowSpan > 0) {
                curRowSpan--;
            }
            // set this to false for the following row
            doRowSpan = false;
            result = true;
        }

        return result;
    }).sortElements(function(a, b){
        a = convertToNum($(a).text());
        b = convertToNum($(b).text());

        return (
            isNaN(a) || isNaN(b) ?
            a > b : +a > +b
        ) ?
            inverse ? -1 : 1 :
            inverse ? 1 : -1;
        },function(){
            return this.parentNode;
        });
        inverse = !inverse;
    }
    function convertToNum(str){
        if(isNaN(str)){
            var holder = "";
            for(i=0; i

Considering question 2; let's deduct where it comes from. First of all we would like to check whether a > b, and, as you already saw correctly, we make a difference between string comparison and number comparison.

We would then simply give:

return (
        isNaN(a) || isNaN(b) ?
        a > b : +a > +b
        ) ? 1 : -1;

This checks whether a > b (either string-wise or number-wise) and then returns 1 on true and -1 on false.

Now we insert the inverse parameter, which should inverse the result. This means that if inverse == true, then 1 becomes -1 and -1 becomes 1. In code, this bold piece of text would replace each occurrence of 1 with inverse ? -1 : 1 and each occurrence of -1 with inverse ? 1 : -1. Which is exactly what is done in the resulting code.

UPDATE: Added doRowSpan in the code because it should not adapt the index if we are in the that contains the rowspan-td.