Working with the form, automatic substitution, how to do it?

Question

Yii

I have registered on the site, how can I insert an automatic value in comment_author so that the user does not write the name ?
<?php $form->field($model, 'comment_author')?>

Answer 1

$model->comment_author = 111;

<?php $form->field($model, 'comment_author')?>

Answer 2

In the controller action:

public function actionComment()
{
    ..............
    ...............
    if (!Yii::$app->user->isGuest) {
        $model->comment_author = Yii::$app->user->identity->username;
    }
    return $this->render('comment', ['model' => $model]);
}

In general, isn't it easier to hide the field with the username if it is authorized? Just substitute it before $model->save().