title: How to get access to grouped records from groupHeaderTpl in grouped grid?
body: <p>I´m working on an auditing results view. The view consists basically on a grid where user can see who changed which values, when he/she did it, from what ip address, etc.</p>
  
  <p><img src="https://i.stack.imgur.com/BlZYe.png" alt="enter image description here"></p>
  
  <p>The point is that I want to group records by 'changeset' field (a GUID field existing in the model which is useful to know that a set of changes were performed as part of one bigger operation) and display in the group header a little summary about the changeset.</p>
  
  <p>For example, I would like to show: "Date: 12/12/2012 15:04:32 - User: ontivero - Updated subscription details".</p>
  
  <p>The first problem that I have is 'User' (or 'Changed By') is not available for the groupHeaderTpl template and the second problem is the grouped rows or records are not available neither. I need the rows because I have to analyse them in order to be able to display a more useful information.</p>
  
  <p>Summarizing, the question should be: how can i have access to the grouped rows to use them in the groupHeaderTpl template?</p>
  
  <p>I have read the documentation (<a href="http://docs.sencha.com/ext-js/4-1/#!/api/Ext.grid.feature.Grouping" rel="nofollow noreferrer">http://docs.sencha.com/ext-js/4-1/#!/api/Ext.grid.feature.Grouping</a>) but the 'children' property doesn´t work.</p>