blob: cf10f54b282142c05c02582a4f0139a6538c31db [file] [log] [blame]
// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'dart:async';
import 'package:stack_trace/stack_trace.dart';
import '../hijack_exception.dart';
import '../middleware.dart';
/// Middleware which prints the time of the request, the elapsed time for the
/// inner handlers, the response's status code and the request URI.
/// If [logger] is passed, it's called for each request. The `msg` parameter is
/// a formatted string that includes the request time, duration, request method,
/// and requested path. When an exception is thrown, it also includes the
/// exception's string and stack trace; otherwise, it includes the status code.
/// The `isError` parameter indicates whether the message is caused by an error.
/// If [logger] is not passed, the message is just passed to [print].
Middleware logRequests({void logger(String msg, bool isError)}) =>
(innerHandler) {
if (logger == null) logger = _defaultLogger;
return (request) {
var startTime = new;
var watch = new Stopwatch()..start();
return new Future.sync(() => innerHandler(request)).then((response) {
var msg = _getMessage(startTime, response.statusCode,
request.requestedUri, request.method, watch.elapsed);
logger(msg, false);
return response;
}, onError: (error, stackTrace) {
if (error is HijackException) throw error;
var msg = _getErrorMessage(startTime, request.requestedUri,
request.method, watch.elapsed, error, stackTrace);
logger(msg, true);
throw error;
String _formatQuery(String query) {
return query == '' ? '' : '?$query';
String _getMessage(DateTime requestTime, int statusCode, Uri requestedUri,
String method, Duration elapsedTime) {
return '${requestTime.toIso8601String()} '
'${elapsedTime.toString().padLeft(15)} '
'${method.padRight(7)} [$statusCode] ' // 7 - longest standard HTTP method
String _getErrorMessage(DateTime requestTime, Uri requestedUri, String method,
Duration elapsedTime, Object error, StackTrace stack) {
var chain = new Chain.current();
if (stack != null) {
chain = new Chain.forTrace(stack)
.foldFrames((frame) => frame.isCore || frame.package == 'shelf')
var msg = '$requestTime\t$elapsedTime\t$method\t${requestedUri.path}'
if (chain == null) return msg;
return '$msg\n$chain';
void _defaultLogger(String msg, bool isError) {
if (isError) {
print('[ERROR] $msg');
} else {