framework/base/Model.php
public function activeAttributes()
    {
        $scenario = $this->getScenario();
        $scenarios = $this->scenarios();
        if (!isset($scenarios[$scenario])) {
            return [];
        }
        $attributes = array_keys(array_flip($scenarios[$scenario]));
        foreach ($attributes as $i => $attribute) {
            if ($attribute[0] === '!') {
                $attributes[$i] = substr($attribute, 1);
            }
        }

        return $attributes;
    }
public function activeAttributes()
    {
        $scenario = $this->getScenario();
        $scenarios = $this->scenarios();
        if (!isset($scenarios[$scenario])) {
            return [];
        }
        $attributes = array_keys(array_flip($scenarios[$scenario]));
        foreach ($attributes as $i => $attribute) {
            if ($attribute[0] === '!') {
                $attributes[$i] = substr($attribute, 1);
            }
        }

        return $attributes;
    }
Returns the attribute names that are subject to validation in the current scenario.
@return string[] safe attribute names