如何获取yii2 select2小部件所选选项的值

use yii\helpers\ArrayHelper;
use yii\widgets\ActiveForm;

$form = ActiveForm::begin();
echo $form->field($model, 'attribute')->widget(\kartik\select2\Select2::classname(), [
    'data' => ArrayHelper::map($options, 'id', 'name'),
    'options' => ['placeholder' => 'Select option...'],
    'pluginOptions' => [
        'allowClear' => true
    ],
]);
ActiveForm::end();

public function actionSubmitForm()
{
    $model = new YourModel();
    if ($model->load(Yii::$app->request->post()) && $model->validate()) {
        $selectedValue = $model->attribute;
        // 处理所选选项的值
    }
}