我是nodejs及其路由系统的新手 . 我收到了“发送后无法设置 Headers ” . 仅在Heroku上的 生产环境 模式(它在本地工作正常) .
//登录=========================================
router.get('/', ifLoggedOut, function(req, res, next){
res.render('login', { message: req.flash('message')});
});
router.post('/login', function(req, res, next){
var username = req.body.username;
var password = req.body.password;
req.checkBody('username', 'Username field is required').notEmpty();
req.checkBody('username', 'Password field is required').notEmpty();
req.checkBody('password', 'Invalid Credintials').len(8, 20);
req.checkBody('username', 'Invalid Credintials').len(4, 20);
var errors = req.validationErrors();
if(errors) {
res.render('login.ejs', {errors: errors});
} else {
passport.authenticate('local-login', {
successRedirect : '/list', // redirect to the secure list section
failureRedirect : '/', // redirect back to the signup page if there is an error
failureFlash : true // allow flash messages
})(req, res, next);
}
});
//功能=============================================== =
function ifLoggedIn(req, res, next) {
// if user is authenticated in the session, carry on
if (req.isAuthenticated()) {
return next();
}
console.log("cannot found in session");
res.redirect('/');
}
function ifLoggedOut(req, res, next){
if(req.isAuthenticated()){
res.redirect('/list');
}
return next();
}
app.use('/', router);
}
// Heroku的错误日志
2015-08-20T07:37:07.490091 00:00 app [web.1]:错误:发送后无法设置标头 . 2015-08-20T07:37:07.490096 00:00 app [web.1]:at ServerResponse.OutgoingMessage.setHeader(_http_outgoing.js:335:11)2015-08-20T07:37:07.490098 00:00 app [web . 1]:在ServerResponse.header(/app/node_modules/express/lib/response.js:718:10)2015-08-20T07:37:07.490099 00:00 app [web.1]:at ServerResponse.send(/ app / node_modules / express / lib / response.js:163:12)2015-08-20T07:37:07.490101 00:00 app [web.1]:at done(/app/node_modules/express/lib/response.js :957:10)2015-08-20T07:37:07.490103 00:00 app [web.1]:在View.exports.renderFile [作为引擎](/app/node_modules/ejs/lib/ejs.js:355: 10)2015-08-20T07:37:07.490105 00:00 app [web.1]:at View.render(/app/node_modules/express/lib/view.js:126:8)2015-08-20T07:37 :07.490106 00:00 app [web.1]:at tryRender(/app/node_modules/express/lib/application.js:639:10)2015-08-20T07:37:07.490108 00:00 app [web.1] :at EventEmitter.render(/app/node_modules/express/lib/application.js:591:3)2015-08-20T07:37:07.490109 00:00 app [web.1]:at ServerResponse.render(/ app /node_modules/express/lib/response.js:961:7)2015-08-20T07:37:07.490111 00:00 app [web.1]:at /app/routes/routes.js:7:7 2015-08 -20T07:37:07.490112 00:00 app [web.1]:在Layer.handle [as handle_request](/app/node_modules/express/lib/router/layer.js:95:5)2015-08-20T07: 37:07.490114 00:00 app [web.1]:at next(/app/node_modules/express/lib/router/route.js:131:13)2015-08-20T07:37:07.490115 00:00 app [web .1]:at ifLoggedOut(/app/routes/routes.js:181:10)2015-08-20T07:37:07.490117 00:00 app [web.1]:在Layer.handle [as handle_request](/ app /node_modules/express/lib/router/layer.js:95:5)2015-08-20T07:37:07.490118 00:00 app [web.1]:at next(/ app / node_modules / express / lib / router / route.js:131:13)2015-08-20T07:37:07.490119 00:00 app [web.1]:at Route.dispatch(/app/node_modules/express/lib/router/route.js:112:3 )
1 回答
此问题出现在
ifLoggedIn
和ifLoggedOut
函数中,其中next()
回调被调用,然后redirect()
进行两次后续渲染调用 . 通过将return
与next()
回调一起使用,可以避免这些错误 .原始代码:
固定版本:
或者
if else
可以正确使用(不需要return
):尽管如此,使用
return
是避免这些错误的好习惯 .