flush controller cache

How can i implement flushing particular cache for particular get request for controller if controller has next code:


public function filters()

    {

            return array(

                    array(

                            'COutputCache -Search -Captcha',

                            'duration'=>86400*31,

                            'varyByParam'=>array('product_slug'),

                            'varyByRoute'=>true,

                            'requestTypes'=>array('GET'),

                            'varyByExpression'=>"Yii::app()->user->hasFlash('contact')"

                    ),

            );

    }

How can i flush cache only for particular get request?

nobody knows ?

I solved and wrote this wiki page

how to invalidate specific page