app/code/community/Nexcessnet/Turpentine/Model/Observer/Esi.php
public function replaceFormKeyPlaceholder($eventObject) {
        if (Mage::registry('replace_form_key')) {
            $esiHelper = Mage::helper('turpentine/esi');
            $response = $eventObject->getResponse();
            $responseBody = $response->getBody();
            $responseBody = str_replace('{{form_key_esi_placeholder}}',
                $esiHelper->buildEsiIncludeFragment(
                    $esiHelper->getFormKeyEsiUrl() ),
                $responseBody);
            $response->setBody($responseBody);
        }
    }
public function replaceFormKeyPlaceholder($eventObject) {
        if (Mage::registry('replace_form_key')) {
            $esiHelper = Mage::helper('turpentine/esi');
            $response = $eventObject->getResponse();
            $responseBody = $response->getBody();
            $responseBody = str_replace('{{form_key_esi_placeholder}}',
                $esiHelper->buildEsiIncludeFragment(
                    $esiHelper->getFormKeyEsiUrl() ),
                $responseBody);
            $response->setBody($responseBody);
        }
    }
public function replaceFormKeyPlaceholder ( $ eventObject ) { if ( Mage :: registry ( 'replace_form_key' ) ) { $ esiHelper = Mage :: helper ( 'turpentine/esi' ) ; $ response = $ eventObject -> getResponse ( ) ; $ responseBody = $ response -> getBody ( ) ; $ responseBody = str_replace ( '{{form_key_esi_placeholder}}' , $ esiHelper -> buildEsiIncludeFragment ( $ esiHelper -> getFormKeyEsiUrl ( ) ) , $ responseBody ) ; $ response -> setBody ( $ responseBody ) ; } }
Replace the form key placeholder with the ESI include fragment

@param  Varien_Object $eventObject
@return null
Replace the form key placeholder with the ESI include fragment