File validation doesn't work, why?

Question

Yii

Hey!
I upload the file to the server using Yii2.
Model:

public $attachment;
public function rules()
    {
        return [
            [['sender_id', 'incoming_number', 'incoming_date', 'delivery_type_id', 'attachment'], 'required'],
            [['sender_id', 'delivery_type_id', 'status_id'], 'integer'],
            [['outgoing_date', 'incoming_date', 'status_id', 'created'], 'safe'],
            [['attachment'], 'file', 'skipOnEmpty' => false, 'extensions' => 'png, jpg, xls, docx, pdf'],
            [['comments'], 'string'],
            [['outgoing_number', 'incoming_number', 'summary', 'attachment'], 'string', 'max' => 255],
            [['status_id'], 'exist', 'skipOnError' => true, 'targetClass' => DocumentStatus::className(), 'targetAttribute' => ['status_id' => 'id']],
            [['delivery_type_id'], 'exist', 'skipOnError' => true, 'targetClass' => DeliveryTypes::className(), 'targetAttribute' => ['delivery_type_id' => 'id']],
            [['sender_id'], 'exist', 'skipOnError' => true, 'targetClass' => Senders::className(), 'targetAttribute' => ['sender_id' => 'id']],
        ];
    }

Controller:

$model = new Documents();
            if($model->load(Yii::$app->request->post()) && $model->validate()) {
$newDoc = new Documents();
$newDoc->sender_id = $model->sender_id;
$model->attachment = UploadedFile::getInstance($model, 'attachment');
$model->attachment->saveAs('uploads/documents/'.$model->attachment->name."-".date('YmdHis').$model->attachment->extension);
$newDoc->attachment = "filezzz";
}

When you click on the submit, it says that attachment cannot be empty. Why??? I'm assigning a value to it

Answer 1

After all, the docks have everything: https://github.com/yiisoft/yii2/blob/master/docs/g...
you have a problem that you run validation before specifying the uploaded file, in the examples of the docks there is a normal implementation and controller actions and models. Remove all logic in the model. if the model is AR then inherit from it and implement this logic or raise a separate form model

Answer 2

because your attachment in rules is described first as a file, and then as a string and cannot be saved, because in attachment after
is an object, not a string. the solution is here, this is loading through an additional model

$imageModel = new UploadImageForm();
$imageModel->files = UploadedFile::getInstances($imageModel, 'files');

if ($imageModel->validate()) {
   $imageModel->files //тут ваш скрипт чтобы сохранить файл
}

//ну и сама основная модель
if ($model->load(Yii::$app->request->post())) {
    $model->save();
}

the model for the file can be taken for example here
https://yiiframework.com.ua/ru/doc/guide/2/input-f...