public function showChangesAction()
    {
        $patchLevels = $this->db->fetchPairs('SELECT DISTINCT gpa_level, gpa_level FROM gems__patches ORDER BY gpa_level DESC');

        $searchData['gpa_level'] = reset($patchLevels);

        if ($this->request instanceof \Zend_Controller_Request_Abstract) {
            $searchData = $this->request->getParams() + $searchData;
        }

        $snippet = $this->addSnippet(
                'Database\\StructuralChanges',
                'patchLevels', $patchLevels,
                'searchData', $searchData
                );

        if (1 == $this->request->getParam('download')) {
            $snippet->outputText($this->view, $this->_helper);
        }
    }