Why does it always output null for input?

Question

Yii

I solved the issue by doing this by default in the model so that the user id is displayed, but for the sake of interest, for the first time I encountered such a problem that it constantly displays null for me. even if required still fails validation.

class Zakaz extends ActiveRecord
{
const SCENARIO_DEFAULT  = 'default';

public function scenarios()
    {
        return [
            self::SCENARIO_DECLINED => ['declined', 'required'],
            self::SCENARIO_DEFAULT => ['id_shop', ...],
        ];
public function rules()
    {
        return [
            [['srok', 'number', 'description', 'phone', 'id_client', 'id_shop'], 'required', 'on' => self::SCENARIO_DEFAULT],
            ['declined', 'required', 'message' => 'Введите причину отказа', 'on'=> self::SCENARIO_DECLINED],
            [['id_shop', ...], 'integer'],
//            ['id_shop', 'default', 'value' => Yii::$app->user->getId()],
           ...
        ];
    }
    }

And in the view

<?= $form->field($model, 'id_shop')->textInput(['value' => Yii::$app->user->id]) ?>

Answer 1

Why does it always output null for input

what are you speaking about? Is your value null?
judging by the code, value gets into Yii::$app->user->idand it is null, there is a user not registered. If there is no user, what id do you expect to see?
There is another important question, when is it null? For there is a form, then it is sent, validated, saved and displayed again. At what point is null and why do you expect it to be otherwise?