Conditional validation

There are cases when it is necessary to enable or disable specific validation rules in the model. Yii2 provides a mechanism to do that.

Getting ready

Create a new application by using the Composer package manager, as described in the official guide at http://www.yiiframework.com/doc-2.0/guide-startinstallation.html.

How to do it...

1. Create a form file, @app/models/DeliveryForm.php, as follows:

   <?php
   namespace app\models;
   use app\components\WordsValidator;
   use yii\base\Model;
   class DeliveryForm extends Model
   {
       const TYPE_PICKUP = 1;
       const TYPE_COURIER = 2;
       public $type;
       public $address;
       public function rules()
       {
           return [
               ['type', 'required'],
               ['type', 'in', 'range'=>[self::TYPE_PICKUP, self::TYPE_COURIER]],
               ['address', 'required', 'when' => function ($model) {
                   return $model->type == self::TYPE_COURIER;
               }, 'whenClient' => "function (attribute, value) {
             ...