title: Sencha Touch Customize Navigation Bar in navigation view
body: <p>I'm doing a simple app which has a navigation view for containing a list, when you press the list I wanna show some HTML or something, but a "new" window so I can take advantage of the back-button on the navigationbar.</p>
  
  <p>My problem now is that I need a search field on the navigationbar, for the inital showing, the problem is that I don't understand how to modify the navigationbar so it gets a search bar. Here's my code:</p>
  
  <pre><code>Ext.define('AppName.view.MainNav', {
  extend: 'Ext.navigation.View',
  
  xtype: 'mainnav',
  
  requires: [
      'Ext.field.Search', 'Ext.TitleBar'
  ],
  
  config: {
      fullscreen: true,
      items: [
          {
          navigationBar: {
              xtype: 'titlebar',
              items: [
                  { xtype: 'spacer' },
                  {
                      xtype: 'searchfield',
                      placeHolder: 'Search...',
  
                      }
                  },
                  { xtype: 'spacer' }
              ]
          },
  
          xtype: 'list',
          fullscreen: true,
  
          store: {
              fields: ['name', 'number'],
              sorters: 'name',
              data: [
                  {name: 'bla', number: 0},
                  {name: 'blo', number: 1},
                  {name: 'bliblo', number: 2},
                  {name: 'Bliblablo', number: 3},
                  {name: 'bliboasdas', number: 4},
              ]
          },
  
          itemTpl: '{name}'
          }
      ]
  }
  </code></pre>
  
  <p>});</p>
  
  <p>There is now No search field on the navigationbar, it's just empty. How do I fix? Thanks in advance!</p>