code: public function getClientOptions($model, $attribute)
      {
          $options = [
              'trueValue' => $this->trueValue,
              'falseValue' => $this->falseValue,
              'message' => $this->formatMessage($this->message, [
                  'attribute' => $model->getAttributeLabel($attribute),
                  'true' => $this->trueValue === true ? 'true' : $this->trueValue,
                  'false' => $this->falseValue === false ? 'false' : $this->falseValue,
              ]),
          ];
          if ($this->skipOnEmpty) {
              $options['skipOnEmpty'] = 1;
          }
          if ($this->strict) {
              $options['strict'] = 1;
          }
  
          return $options;
      }
docs: {@inheritdoc}