title: ExtJS extend grid RowEditor plugin (to edit array)
body: <p>I've been using the <a href="http://docs.sencha.com/ext-js/4-0/extjs/examples/grid/row-editing.html" rel="noreferrer">ExtJS grid row editing plugin</a> pretty liberally for CRUD operations in web applications. Now, I have a requirement to allow a database record to be edited along with a related collection/array (from another datastore) using this row editing plugin.</p>
  
  <p>To do this I want to insert drag-n-drop grids inside of a row that has been selected for editing, one grid showing the available (unused) collection items on the left and another grid to hold the defined collection items on the right.</p>
  
  <p>To illustrate what I am trying to do, here is the normal row editing plugin with a row selected for editing:</p>
  
  <p><img src="https://i.stack.imgur.com/Hjbj4.png" alt="grid with row editing"></p>
  
  <p>I am trying to do this (drag-n-drop grids inside of row editor div):</p>
  
  <p><img src="https://i.stack.imgur.com/zlEsu.png" alt="grid with row editing plus another grid inside"></p>
  
  <p>To do this I have been trying to simply run something like <code>Ext.getCmp(???).add(myDnDGridPanel);</code> but I haven't found the right thing to attach this to (what to put in the question marks).</p>
  
  <p>It seems reasonable enough to use this plugin to edit the related collection/array along with the database record. Does anyone know a simple way to add items to this row editor div?</p>
  
  <p>Or... will I have to hack/extend the plugin to accomplish this?</p>