title: How to set editor for a column programmatically in a grid
body: <p>I have a <code>Ext.grid.Panel</code> with a set of columns. This grid is filtered, and depending on the filter I would like to define an editor for a column.</p>
  
  <p>My grid: </p>
  
  <pre><code>Ext.define('Mb.view.MyPanel', {
      extend: 'Ext.grid.Panel',
      columns: [
          {text: 'Order #', dataIndex: 'id'},
          {text: 'Action', dataIndex: 'type',
              renderer: function(value){
                  if(value == 'BP') return Lang._('Veuillez choisir')
                   return ''
              }
          },
  </code></pre>
  
  <p>Now I would like to do something like:</p>
  
  <pre><code>var panel = Mb.app.getView('MyPanel');
  if (condition == true) {
      panel.getColumns[1].setEditor({
          xtype: 'textfield',
          ...
      })
  }
  </code></pre>
  
  <p>Obviously the methods <code>getColumns</code> and <code>setEditor</code> do not exist. I therefore need another method to activate an editor on that column.<br>
  I didn't find a method to access the column definitions to modifiy them and to rerender the grid afterwards. </p>
  
  <p>Can you give me a hint in which direction to search ? Thanks.</p>