title: GroupingStore order groups by total in each group
body: <p>Team(s) - I am using Extjs v. 3x and have the entire grouping using the grouping store working perfectly but what I can't seem to figure out is how to render the actual groups (not the underlying records) based on the total in each group. </p>
  
  <pre><code>requestGrid = new Ext.ux.SearchPageingGridPanel({
      height:500
      //,title:'Application User Listing'
      ,store: trackerStore
      ,columns: userColumns // or define inline via columns
      ,collapsible:false
      //,stateId : "requestsdffasdfd"
      ,header: true
      ,view: new Ext.grid.GroupingView({
          forceFit:true,
          showGroupName: true,
          enableNoGroups:false,
          enableGroupingMenu:false,
          startCollapsed: true,
          autoFill: true,
          groupMode: 'display',
          hideGroupedColumn: false,
          groupTextTpl: ' ({[values.rs.length]} {[values.rs.length &gt; 1 ? "Items" : "Item"]}) {text}'
      })
      ,renderTo: 'grid-paneling'
  
  });
  </code></pre>
  
  <p>The above is my code using the GroupingView and what I want to do is show the group ordering based on values.rs.lenght.</p>
  
  <p>So for example: if I have 3 groups.</p>
  
  <p>(3 Items) Column Group Name
  (6 Items) Column Group Name
  (2 Items) Column Group Name</p>
  
  <p>I want to display in this order.</p>
  
  <p>(6 Items) Column Group Name
  (3 Items) Column Group Name
  (2 Items) Column Group Name</p>