title: Sencha Touch 2 - "change" event listener for textfield
body: <p>I would like to add an event listener for the change event on a textfield. I created a view which contains a form panel - everything works so far.</p>
  <p>Now I tried to add a event listener to one of the textfields:</p>
  <pre><code>  items:[
          {
              xtype    :&quot;textfield&quot;,
              name     :&quot;field&quot;,
              label    :&quot;field&quot;,
              required :true,
              listeners:{
                  change:{
                      fn    : &quot;onChangeHandler&quot;,
                      scope: this
                  },
              }
      },
  </code></pre>
  <p>But it doesn't really work .. nothing happens. No errors and no function call. What am I doing wrong?</p>
  <p>EDIT:</p>
  <p>Tried another thing - directly within the item definition:</p>
  <pre><code>    {
      xtype    :&quot;textfield&quot;,
      name     :&quot;field&quot;,
      label    :&quot;field&quot;,
      required :true,
      listeners:{
          change:{
              fn    :this.onChange
          },
          scope :this
      }
  },
  </code></pre>
  <p>But then on change I got this error on console:</p>
  <blockquote>
  <p>Uncaught TypeError: Cannot call method 'apply' of undefined</p>
  </blockquote>