title: How to prepend / append bootstrap3 icon to Active Form in yii2 alpha
body: <p>This is how i added the icon with text field. Also added the image of generated output.
  I don't want to use <a href="http://demos.krajee.com/" rel="nofollow noreferrer">Krajee Yii Extensions</a>. So i started to read the documentation.</p>
  
  <pre><code>$form =  \yii\widgets\ActiveForm::begin([
    'id' =&gt; 'form-id',
    'options' =&gt; ['class' =&gt; 'form-horizontal'],
    'enableClientValidation'=&gt; false,
    'enableAjaxValidation'=&gt; true,
    'validateOnSubmit' =&gt; true,
    'validateOnChange' =&gt; true,
    'validateOnType' =&gt; true,
    'action' =&gt; 'youraction',
    'validationUrl' =&gt; 'yourvalidation'
  ]);        
  
      echo $form-&gt;field($model, 'fieldname')-&gt;begin();
        echo Html::activeLabel($model,'fieldname', ["class"=&gt;"col-sm-3 control-label"]); ?&gt;
        &lt;div class="input-group col-sm-4 "&gt;
          &lt;span class="input-group-addon"&gt;
            &lt;span class="glyphicon glyphicon-subtitles"&gt;&lt;/span&gt;
          &lt;/span&gt;
          &lt;?php echo Html::activeTextInput($model, 'fieldname', [
              'class'=&gt;'form-control',
              'autocomplete'=&gt;'off'
            ]
          ); ?&gt;
        &lt;/div&gt;
        &lt;?php echo Html::error($model,'origin', ['class' =&gt; 'help-block']);
      echo $form-&gt;field($model, 'origin')-&gt;end();
  
  \yii\widgets\ActiveForm::end(); 
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/eMo7z.png" alt="Example View"></p>