def wsgi(self, environ, start_response):
        """ The bottle WSGI-interface. """
        try:
            environ['bottle.app'] = self
            request.bind(environ)
            response.bind()
            out = self._handle(environ)
            out = self._cast(out, request, response)
            # rfc2616 section 4.3
            if response.status in (100, 101, 204, 304) or request.method == 'HEAD':
                if hasattr(out, 'close'): out.close()
                out = []
            status = '%d %s' % (response.status, HTTP_CODES[response.status])
            start_response(status, response.headerlist)
            return out
        except (KeyboardInterrupt, SystemExit, MemoryError):
            raise
        except Exception as e:
            if not self.catchall: raise
            err = '<h1>Critical error while processing request: %s</h1>' \
                  % environ.get('PATH_INFO', '/')
            if DEBUG:
                err += '<h2>Error:</h2>\n<pre>%s</pre>\n' % repr(e)
                err += '<h2>Traceback:</h2>\n<pre>%s</pre>\n' % format_exc(10)
            environ['wsgi.errors'].write(err) #TODO: wsgi.error should not get html
            start_response('500 INTERNAL SERVER ERROR', [('Content-Type', 'text/html')])
            return [tob(err)]