textFieldGroup no editable

Hi people, I need that when the textFieldGropu has a content, the textFieldGropu shouldn’t be editable.

<?php echo $form->textFieldGroup(

			$model,

			'textField',

			array(

				'wrapperHtmlOptions' => array(

					'class' => 'col-sm-5',

				),

				'hint' => 'In addition to freeform text, any HTML5 text-based input appears like so.'

			)

		); ?>

Thanks you very much!

http://www.yiiframework.com/doc-2.0/guide-input-validation.html#conditional-validation