PHP 開発フレームワーク Yii Framework チュートリアル (21) UI コンポーネントのキャプチャの例

class MathCaptchaAction
extends CCaptchaAction{
protected function generateVerifyCode(){return mt_rand((int)$this->minLength,(int)$this->maxLength);}
public function renderImage($code){parent::renderImage($this->getText($code));}
protected function getText($code){$code=(int)$code;$rand=mt_rand(1,$code-1);$op=mt_rand(0,1);if($op){
return $code-$rand. '+' . $rand;
}else{return $code+$rand. '-' . $rand;}}}

public function actions()
{
return array(
'captcha'=>array(
'class' => 'MathCaptchaAction',
'minLength' => 1,
'maxLength' => 10,
)