framework/validators/BooleanValidator.php
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 $options;
    }
public function getClientOptions($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;
    }
{@inheritdoc}