Magento filter payment method besed on shipping method

Question

I develop observer method in Magento for filter payment methods based on shipping methods. This is my method:

class Devpassion_Paymentfilter_Model_Observer {

public function paymentMethodIsActive(Varien_Event_Observer $observer) {
    $event           = $observer->getEvent();
    $method          = $event->getMethodInstance();
    $result          = $event->getResult();
    $carriers = Mage::getSingleton('shipping/config')->getActiveCarriers();

        foreach ($carriers as $carrier) {
     //       $carrierCode = $carrier->getId();

            if ($carrier->getId() == 'flatrate' ){
                    if($method->getCode() == 'checkmo' OR $method->getCode() == 'paypal_standard'){
                        $result->isAvailable = true;
                    }else{
                        $result->isAvailable = false;
                    }
                }

             }
    }
}

Results of this is that for all shipping method this filter is true. So for all shipping method paypal and money check shows up and all other not.

Please advice me how to set up this condition to filter just for one specific shipping method.

Answer 1

public function paymentMethodIsActive($observer)
    {
        /**
         * @var $quote Mage_Sales_Model_Quote
         */
        $quote  = $observer->getEvent()->getQuote();
        $method = $observer->getEvent()->getMethodInstance();
        $result = $observer->getEvent()->getResult();

        $shipping_method = $quote->getShippingAddress()->getShippingMethod();
        if ($shipping_method == 'flatrate_flatrate' && $method->getCode() == 'checkmo') {
            $result->isAvailable = false;
        }
    }