title: Yii2 auto complete - value missing in the field on update
body: <p>I am using the yii2 auto complete widget, it is working fine, except when I update the form the field shows blank.</p>
  
  <pre><code>use yii\jui\AutoComplete;
  use yii\web\JsExpression;
  
  $data = app\models\Doctor::find()
      -&gt;select(['doctor_name as value', 'doctor_name as  label','id as id'])
      -&gt;asArray()
      -&gt;all();
  </code></pre>
  
  <p>and after that the auto-complete code like this</p>
  
  <pre><code>echo 'Doctor' .'&lt;br&gt;';
    echo AutoComplete::widget([
      'name' =&gt; 'Doctor',    
      'id' =&gt; 'ddd',
      'clientOptions' =&gt; [
          'source' =&gt; $data, 
          'autoFill'=&gt;true,
           'select' =&gt; new JsExpression("function( event, ui ) {
          $('#appoinment-doctor_name').val(ui.item.id);
       }")],
       ]);
  &lt;?= Html::activeHiddenInput($model, 'doctor_name')?&gt;
  </code></pre>
  
  <p>What I am missing here? How can I get the value on update?</p>