DataTables plug-in for supporting custom sorting of any data type using a simple comment prefix in the field. Place the sortable value using a string, float, integer or date to sort with. In the format <!-- CDX:<data> --> where "X" is "S" for string, "I" for Integer, "F" for Float, "D" for Date.

gistfile1.js

/* DataTables plug-in to allow for a custom Data Value for sorting based on a comment */
jQuery.fn.dataTableExt.aTypes.unshift(function(sData) {
    /* Look for a special comment <!-- CDx:<data> --> if found then return that type */
    if (sData.indexOf('<!-- CDI:') >= 0) {
        return 'comment-dt-integer';
    } else if (sData.indexOf('<!-- CDS:') >= 0) {
        return 'comment-dt-string';
    } else if (sData.indexOf('<!-- CDF:') >= 0) {
        return 'comment-dt-float';
    } else if (sData.indexOf('<!-- CDD:') >= 0) {
        return 'comment-dt-date';
    } else {
        return null;
    }
});

jQuery.extend(jQuery.fn.dataTableExt.oSort, {
    "comment-dt-integer-pre": function(a) {
        var sPos = a.indexOf('<!-- CDI:') + 9;
        return parseInt(a.substr(sPos, a.indexOf(" -->", sPos) - sPos),10);
    },

    "comment-dt-integer-asc": function(a, b) {
        return a - b;
    },

    "comment-dt-integer-desc": function(a, b) {
        return b - a;
    }
});

jQuery.extend(jQuery.fn.dataTableExt.oSort, {
    "comment-dt-float-pre": function(a) {
        var sPos = a.indexOf('<!-- CDF:') + 9;
        return parseFloat(a.substr(sPos, a.indexOf(" -->", sPos) - sPos));
    },

    "comment-dt-float-asc": function(a, b) {
        return a - b;
    },

    "comment-dt-float-desc": function(a, b) {
        return b - a;
    }
});

jQuery.extend(jQuery.fn.dataTableExt.oSort, {
    "comment-dt-string-pre": function(a) {
        var sPos = a.indexOf('<!-- CDS:') + 9;
        return a.substr(sPos, a.indexOf(" -->", sPos) - sPos);
    },

    "comment-dt-string-asc": function(a, b) {
        return ((a < b) ? -1 : ((a > b) ? 1 : 0));
    },

    "comment-dt-string-desc": function(a, b) {
        return ((a < b) ? 1 : ((a > b) ? -1 : 0));
    }
});

jQuery.extend(jQuery.fn.dataTableExt.oSort, {
    "comment-dt-date-pre": function(a) {
        var sPos = a.indexOf('<!-- CDD:') + 9;
        var d = Date.parse(a.substr(sPos, a.indexOf(" -->", sPos) - sPos));
        if (isNaN(d)) {
            return 0;
        }
        return d;
    },

    "comment-dt-date-asc": function(a, b) {
        return a - b;
    },

    "comment-dt-date-desc": function(a, b) {
        return b - a;
    }
});