jQuery tablesorter plugin secondary "hidden" sorting - jquery-plugins

Question

I'm using the jQuery tablesorter plugin and I have a column that contains name of month and year like this
April, 1975
January, 2001
I would like to sort this column as if it were a date column. As I understand it, it is possible to sort the column with some other 'hidden' value, but I just can't seem to find the documentation for that feature. Any help out there?
Update
This fork http://mottie.github.com/tablesorter/docs/index.html of the tablesorter had just what I needed; the ability to store the value to sort by in an attribute, worked really great.

Answer 1

Just using the textExtraction function. Set data-sort-value on your TDs. Defaults to normal text if it's not present.
$(".sort-table").tablesorter({
textExtraction: function(node) {
var attr = $(node).attr('data-sort-value');
if (typeof attr !== 'undefined' && attr !== false) {
return attr;
}
return $(node).text();
}
});

Answer 2

I have a fork of tablesorter that allows you to write a parser that can extract data attributes from the table cell as well as assign specific textExtraction for each column.
$(function(){
$.tablesorter.addParser({
// set a unique id
id: 'myParser',
is: function(s) {
// return false so this parser is not auto detected
return false;
},
format: function(s, table, cell, cellIndex) {
// get data attributes from $(cell).attr('data-something');
// check specific column using cellIndex
return $(cell).attr('data-something');
},
// set type, either numeric or text
type: 'text'
});
$('table').tablesorter({
headers : {
0 : { sorter: 'myParser' }
}
});
});

Answer 3

This is now a STANDARD FEATURE of tablesorter, though it's undocumented for some reason. If you open the file https://github.com/christianbach/tablesorter/blob/master/jquery.tablesorter.js and look at the line # 307 you'll see it supports the "data-sort-value" attribute.
Usage:
<td data-sort-value="42">Answer to the question</td>

Answer 4

It's a bit of a hack (OK, it's a total hack), but if you set the parser for the column to 'text', and pre-fix your pretty output with the string you really want to sort on within a hidden span it will sort correctly.
You can set the parser on a column with the headers option, e.g. to set the parser on the first and second columns to 'text' you would set the following:
headers: {0: {sorter: 'text'}, : {sorter: 'text'}
To do this trick with dates, you can use the ISO8601 date format which sorts lexically. JS's Date objects can generate ISO8601 date strings via the toISOString() function.
Given the CSS:
span.hidden{
display:none;
}
A sample cell in the table would look like this:
<td><span class="hidden">2015-04-18T23:48:33</span>19 April 2015</td>
Not the prettiest code in the world, but it does work.

Answer 5

I am using
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery.tablesorter/2.29.0/js/jquery.tablesorter.min.js"></script>
Working with data-text
<td data-text="42">Answer to the question</td>
Not Working with data-sort-value
<td data-sort-value="42">Answer to the question</td>

Answer 6

You need to write your own parser. Your parser might end up looking something like:
var months = {'January':1,'February':2, ...};
$.tablesorter.addParser({
id: 'myDate',
is: function(s) { return false; },
format: function(s) {
var x = s.split(', ');
return x[1]+'-'+months[x[2]];
},
type: 'numeric'
});
Not tested, but general idea.