Express 500 类型错误:无法读取未定义的属性“get”

这个例子取自 Node Cookbook，但使用 Express 3.1.0：

应用.js

var express = require('express')
  , routes = require('./routes')
  , user = require('./routes/user')
  , http = require('http')
  , path = require('path');
var app = express();
app.configure(function(){
  app.set('port', process.env.PORT || 3000);
  app.set('views', __dirname + '/views');
  app.set('view engine', 'jade');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(express.cookieParser('kooBkooCedoN'));
  app.use(express.session());
  app.use(require('./login'));
  app.use(app.router);
  app.use(express.static(path.join(__dirname, 'public')));
});
app.configure('development', function(){
  app.use(express.errorHandler());
});
// --------------------------
// MODIFICATION IS MADE HERE!
// --------------------------
app.configure(function(){
  app.use(function(req, res, next){
    res.locals.user = req.session.user;
    next();
  });
});
app.get('/', routes.index);
app.post('/', routes.index);
app.del('/', routes.index);
app.get('/:page', routes.index);
http.createServer(app).listen(app.get('port'), function(){
  console.log("Express server listening on port " + app.get('port'));
});

我按照以下建议对代码进行了一些修改：迁移 Express.js 2 到 3，特别是 app.dynamicHelpers（） 到 app.locals.use？

登录.js

var users = {'dave' : 'expressrocks'};
module.exports = function (req, res, next) { var method = req.method.toLowerCase(), //cache the method
    user = req.body.user,
    logout = (method === 'delete'),
    login = (method === 'post' && user),
    routes = req.app.routes.routes[method];
  if (!routes) { next(); return; }
  if (login || logout) {
    routes.forEach(function (route) {
      if (!(req.url.match(route.regexp))) {
        console.log(req.url);
        req.method = 'GET';
      }
    }); 
  }
  if (logout) {
    delete req.session.user; 
  }
  if (login) {
    Object.keys(users).forEach(function (name) {
      if (user.name === name && user.pwd === users[name]) {
        req.session.user = {
          name: user.name,
          pwd: user.pwd
        };
      }
    }); 
  }
  if (!req.session.user) { req.url = '/'; } 
  next(); 
};

登录.翡翠

if user
  form(method='post')
    input(name="_method", type="hidden", value="DELETE")
    p Hello #{user.name}!
      a(href='javascript:', onClick='forms[0].submit()') [logout]
else
  p Please log in
  form(method='post')
    fieldset
      legend Login
      p
        label(for="user[name]") Username:
        input(name="user[name]")
      p
        label(for="user[pwd]") Password:
        input(type="password", name="user[pwd]")
      input(type="submit")

来自终端的结果日志

错误来自以下行：routes = req.app.routes.routes[method];登录时.js

TypeError: Cannot read property 'get' of undefined
    at Object.module.exports [as handle] (/home/chiasyan/Desktop/login/login.js:8:35)
    at next (/home/chiasyan/Desktop/login/node_modules/express/node_modules/connect/lib/proto.js:199:15)
    at store.get.next (/home/chiasyan/Desktop/login/node_modules/express/node_modules/connect/lib/middleware/session.js:309:9)
    at /home/chiasyan/Desktop/login/node_modules/express/node_modules/connect/lib/middleware/session.js:333:9
    at /home/chiasyan/Desktop/login/node_modules/express/node_modules/connect/lib/middleware/session/memory.js:50:9
    at process.startup.processNextTick.process._tickCallback (node.js:244:9)

更新：我已经更改了 routes = req.app.routes.routes[method];但仍然有一个小错误。

在login.jade中找不到user变量（user在login中定义过一次.js）

ReferenceError: /home/chiasyan/Desktop/login/views/login.jade:1
  > 1| if user
    2|   form(method='post')
    3|     input(name="_method", type="hidden", value="DELETE")
    4|     p Hello #{user.name}!
user is not defined

引用节点食谱

在 routes/index.js 中，我们现在可以简单地使用以下代码：

索引.js

exports.index = function (req, res) { 
  res.render('index', {title: 'Express'}); 
};

Node Cookbook 中的另一句话

由于我们不再使用路由，因此我们没有机会通过res.render传递req.session.user。但是，我们可以使用 改为动态助手。动态帮助程序可以访问请求和 res 对象，它们在呈现视图之前被调用。任何属性 我们传递给动态帮助程序对象被推送到 Jade 视图，如下所示 局部变量。

由于我无法再在 Express 3.* 中使用动态助手，因此在应用程序中.js我已更改为：

app.configure(function(){
  app.use(function(req, res, next){
    res.locals.user = req.session.user;
    next();
  });
});