Question

我收到以下错误：

/Users/nblavoie/Desktop/HotPie/HotPie/apps/authentication/routes.coffee:6
  app.get('/login', function(req, res) {
  ^
ReferenceError: app is not defined
    at Object.<anonymous> (/Users/nblavoie/Desktop/HotPie/HotPie/apps/authentication/routes.coffee:6:3)
    at Object.<anonymous> (/Users/nblavoie/Desktop/HotPie/HotPie/apps/authentication/routes.coffee:15:4)
    at Module._compile (module.js:449:26)
    at Object.require.extensions..coffee (/Users/nblavoie/Desktop/HotPie/HotPie/node_modules/coffee-script/lib/coffee-script/coffee-script.js:22:21)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    at Object.<anonymous> (/Users/nblavoie/Desktop/HotPie/HotPie/app.js:31:1)
    at Module._compile (module.js:449:26)

尝试将（app）变量传递给以下要求时：

/**
 * Module dependencies.
 */

require('coffee-script');

var express = require('express')
  , 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(app.router);
  app.use(express.static(path.join(__dirname, 'public')));
});

app.configure('development', function(){
  app.use(express.errorHandler());
});

// Routes
**require('./apps/authentication/routes')(app);**

http.createServer(app).listen(app.get('port'), function(){
  console.log("Express server listening on port " + app.get('port'));
});

使用以下文件中的app变量：

routes = (app) -> 
app.get '/login', (req, res) ->
    res.render 'views/login',
        title: 'Login'
        stylesheet: 'login'
module.exports = routes

我知道变量范围从一个JS文件到另一个JS文件是不同的。但为什么以下行：

require('./apps/authentication/routes')(app);

不通过app变量？

Answer 1

就在这里：

ReferenceError: app is not defined
    at Object.<anonymous> (/Users/nblavoie/Desktop/HotPie/HotPie/apps/authentication/routes.coffee:6:3)

错误不在app.js中，它在您的CoffeeScript文件中。查看what it's compiling to：

var routes;

routes = function(app) {};

app.get('/login', function(req, res) {
  return res.render('views/login', {
    title: 'Login',
    stylesheet: 'login'
  });
});

module.exports = routes;

请注意routes是一个空函数？是的，你错过了缩进。将CoffeeScript更改为以下内容应该修复它（注意app.get的缩进及其后的所有内容）：

routes = (app) ->
    app.get '/login', (req, res) ->
        res.render 'views/login',
            title: 'Login',
            stylesheet: 'login'

module.exports = routes

Answer 2

CoffeeScript对缩进非常敏感。这段代码应该有效：

routes = (app) -> 
    app.get '/login', (req, res) ->
        res.render 'views/login',
            title: 'Login'
            stylesheet: 'login'
module.exports = routes

Node.js范围错误

2 个答案: