public function findTemplate($template_name)
    {
        /*
         * Find template location inside search directory path
         */
        if (!$this->app) {
            throw new Exception_InitError('You should use add() to add objects!');
        }
        $f = $this->app->locatePath(
            $this->template_type ?: $this->settings['template_type'],
            $template_name.$this->settings['extension']
        );

        return $this->origin_filename = $f;
    }