Custom Parser for Tablesorter plugin for custom date format

Question

I need to adapt the jQuery Tablesorter plugin to sort dates in a very simple format which will consist of the three letter month and the 4 digit date (e.g. May 2010, Jan 2011, Mar 2012, etc).

I have'nt been able to wrap my head around how to do it. I tried adapting the parser found here: http://beausmith.com/blog/custom-date-sorting-for-jquery-tablesorter-plugin/. But I am lost with reg ex. For ease in helping, I will post his code below.

// TableSort parser for date format: Jan 6, 1978
$.tablesorter.addParser({
id: 'monthDayYear',
is: function(s) {
  return false;
},
format: function(s) {
  var date = s.match(/^(\w{3})[ ](\d{1,2}),[ ](\d{4})$/);
  var m = monthNames[date[1]];
  var d = String(date[2]);
  if (d.length == 1) {d = "0" + d;}
  var y = date[3];
  return '' + y + m + d;
 },
type: 'numeric'
});
var monthNames = {};
monthNames["Jan"] = "01";
monthNames["Feb"] = "02";
monthNames["Mar"] = "03";
monthNames["Apr"] = "04";
monthNames["May"] = "05";
monthNames["Jun"] = "06";
monthNames["Jul"] = "07";
monthNames["Aug"] = "08";
monthNames["Sep"] = "09";
monthNames["Oct"] = "10";
monthNames["Nov"] = "11";
monthNames["Dec"] = "12";

Any ideas on how to just format it for month names and year? Thanks!

UPDATE: I have tried to implement some code both from Sam and Fudgey below (thank you for being so helpful thus far!). I can't quite get it to work. I tried to use fugey's code sample because I see where it is working exactly as needed on the fiddle demo. Below is my HTML markup:

<table id="myTable" class="stripeMe sample" width="100%" cellpadding="0"    cellspacing="0">
<thead>
<th width="30%" align="left">COMPANY</th><th width="35%">DESCRIPTION</th><th width="17%"   align="left">INDUSTRY</th><th width="18%" align="left">EXIT DATE</th></tr></thead>
<tbody>
<tr><td width="30%">   <a href="http://www.cartera.com/vesdia.html "> Cartera Commerce,  Inc.</a>  </td>
<td width="35%">Provides technology-enabled marketing and loyalty solutions 
</td><td width="17%">   Financials  </td><td width="18%">Feb 2010</td></tr><tr><td  width="30%">   <a href="http://www.criticalinfonet.com/ "> Critical Information Network,   LLC</a>  </td>
<td width="35%">Operates library of industrial professional training and certification   materials 
</td><td width="17%">   Education  </td><td width="18%">Apr 2011</td></tr><tr><td     width="30%">   <a href="http://www.cynergydata.com/ "> Cynergydata</a>  </td>
<td width="35%">Provides merchant payment processing services and related software products 
</td><td width="17%">   Merchant Processing  </td><td width="18%">May 2011</td></tr><tr>  <td width="30%">   <a href=" "> EVCI Career Colleges Holding Corp</a>  </td>
<td width="35%">Operates post-secondary schools  
</td><td width="17%">   Education  </td><td width="18%">Jul 2012</td></tr><tr><td  width="30%">   <a href="http://www.groundlink.com/ "> Groundlink, Inc.</a>  </td>
<td width="35%">Provides ground transportation services domestically and internationally 
</td><td width="17%">   Transportation  </td><td width="18%">Feb 2012</td></tr><tr><td  width="30%">   <a href="http://www.haggen.com/ "> Haggen, Inc.</a>  </td>
<td width="35%">Operates chain of high-end grocery stores in the Pacific Northwest 
</td><td width="17%">   Grocery  </td><td width="18%">Aug 2011 </td></tr>

</tbody>
</table>

And then the script I am using, which is fudgey's but I changed the column header number to 3 (it's the 4th column in my table) and I changed the call to the tablesorter to use the id of the table, which in this case is the ever original #myTable. I also wrapped it in jQuery's $(document).ready:

$(document).ready(function() { 
$.tablesorter.addParser({
id: 'monthYear',
is: function(s) {
return false;
},
format: function(s) {
var date = s.match(/^(\w{3})[ ](\d{4})$/);
var m = date ? date[1] + ' 1 ' || '' : '';
var y = date && date[2] ? date[2] || '' : '';
return new Date(m + y).getTime() || '';
},
type: 'Numeric'
});

$('#myTable').tablesorter({
headers: {
    3: {
        sorter: 'monthYear'
    }
}
});
});

And it is still not sorting that column by date, I'm not sure how it is sorting it - I get a sort in this order, which almost seems right but look at where that Feb 2010 falls, right in the middle of 2011 dates - weird: Aug 2011 Feb 2010 Apr 2011 May 2011 Feb 2012 Jul 2012

Answer 1

I've modified @SamTyson's answer:

There are three things that changed:

1. The format function needs to be able to handle empty table cells.
2. The format function must return a string or number
3. The parser type can only be "Numeric" or "Text".

So, I ended up with this parser code and this demo.

$.tablesorter.addParser({
    id: 'monthYear',
    is: function(s) {
        return false;
    },
    format: function(s) {
        // remove extra spacing
        s = $.trim(s.replace(/\s+/g, ' '));
        // process date
        var date = s.match(/^(\w{3})[ ](\d{4})$/),
            m = date ? date[1] + ' 1 ' || '' : '',
            y = date && date[2] ? date[2] || '' : '';
        return new Date(m + y).getTime() || '';
    },
    type: 'Numeric'
});

$('table').tablesorter({
    headers: {
        0: {
            sorter: 'monthYear'
        }
    }
});

Update: Added a line to trim out extra spaces.