NodeJS 类型错误:无法读取未定义的属性“句柄”--- if(fn.handle && fn.set)mount_app = fn

kd3sttzy  于 2023-01-12  发布在  Node.js
关注(0)|答案(4)|浏览(109)

我将感谢一些帮助,请。不确定确切地知道这意味着什么,因为这是我第一次与节点和表达。我设置表达使用节点,并试图按照网站上的信息Express.js。将感谢一些帮助,了解我可能错过了这里请。
...\node_modules\express\lib\application.js:178 if (fn.handle && fn.set) mount_app = fn; ^ TypeError: Cannot read property 'handle' of undefined at Function.app.use (....\node_modules\express\lib\application.js:178:9) at Object.<anonymous> (....\app.js:18:5) at Module._compile (module.js:456:26) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12) at Function.Module.runMain (module.js:497:10) at startup (node.js:119:16) at node.js:906:3

/**
 * Module dependencies.
 */
 var http = require('http'); 
//var express = require('../..');
var module = require("module")
var logger = require('morgan');
var express = require('express');
var app =  module.exports = express();
var silent = 'test' == process.env.NODE_ENV;
var httpServer = http.createServer(app);
var bodyParser = require('body-parser');
var methodOverride = require('method-override');
  // app middleware
app.use(express.static(__dirname + '/public'));
app.use(bodyParser());
app.use(methodOverride());
app.use(logErrors);
app.use(clientErrorHandler);
app.use(errorHandler); 
api.use(logger('dev'));
api.use(bodyParser());
/**
 * CORS support.
 */
api.all('*', function(req, res, next)
{
  if (!req.get('Origin')) return next();// use "*" here to accept any origin
  res.set('Access-Control-Allow-Origin', 'http://localhost:3000');
  res.set('Access-Control-Allow-Methods', 'GET, POST');
  res.set('Access-Control-Allow-Headers', 'X-Requested-With, Content-Type');
  res.set('Access-Control-Allow-Max-Age', 3600);
  if ('OPTIONS' == req.method) return res.send(200);
  next();
});
// middleware with an arity of 4 are considered error handling middleware. When you next(err)
// it will be passed through the defined middleware in order, but ONLY those with an arity of 4, ignoring regular middleware.
var clientErrorHandler=function(err, req, res, next) {
  if (req.xhr) {// whatever you want here, feel free to populate properties on `err` to treat it differently in here.
  res.send(err.status || 500, { error: err.message });
  } 
  else 
  { next(err);}
};
// create an error with .status. we can then use the property in our custom error handler (Connect repects this prop as well)
var error=function (status, msg) {
  var err = new Error(msg);
  err.status = status;
  return err;
};
var logErrors=function (err, req, res, next) {
  console.error(err.stack);
  next(err);
};
var errorHandler=function (err, req, res, next) {
  res.status(500);
  res.render('error', { error: err });
};
// general config
app.set('views', __dirname + '/views');
//app.set('view engine', 'jade');
// our custom "verbose errors" setting which we can use in the templates via settings['verbose errors']
app.enable('verbose errors');// disable them in production use $ NODE_ENV=production node examples/error-pages
if ('production' == app.settings.env) {app.disable('verbose errors');}
        silent || app.use(logger('dev'));
// Routes 
app.get('/404', function(req, res, next){
next();// trigger a 404 since no other middleware will match /404 after this one, and we're not responding here
});

app.get('/403', function(req, res, next){// trigger a 403 error
  var err = new Error('not allowed!');
  err.status = 403;
  next(err);
});

app.get('/500', function(req, res, next){// trigger a generic (500) error
  next(new Error('keyboard cat!'));
});

// Error handlers

// Since this is the last non-error-handling middleware use()d, we assume 404, as nothing else responded.
// $ curl http://localhost:3000/notfound
// $ curl http://localhost:3000/notfound -H "Accept: application/json"
// $ curl http://localhost:3000/notfound -H "Accept: text/plain"
app.use(function(req, res, next){
  res.status(404); 
  if (req.accepts('html')) {// respond with html page
    res.render('404', { url: req.url });
    return;
  } 
  if (req.accepts('json')) {// respond with json
    res.send({ error: 'Not found' });
    return;
  } 
  res.type('txt').send('Not found');// default to plain-text. send()
});

// error-handling middleware, take the same form as regular middleware, however they require an
// arity of 4, aka the signature (err, req, res, next).when connect has an error, it will invoke ONLY error-handling middleware.

// If we were to next() here any remaining non-error-handling middleware would then be executed, or if we next(err) to
// continue passing the error, only error-handling middleware would remain being executed, however here
// we simply respond with an error page.
app.use(function(err, req, res, next){
  // we may use properties of the error object here and next(err) appropriately, or if we possibly recovered from the error, simply next().
  res.status(err.status || 500);
  res.render('500', { error: err });
});

if (!module.parent) {// assigning to exports will not modify module, must use module.exports
  app.listen(3000);
  silent || console.log('Express started on port 3000');
};
gt0wga4j

gt0wga4j1#

问题是你试图use()一个还没有定义的变量。如果你使用function logErrors(err, req, res, next) {语法而不是var logErrors=function (err, req, res, next) {,你的TypeErrors应该会消失。

biswetbf

biswetbf2#

尝试移动变量clientErrorHandler,errorHandler等之前,你调用应用程序。用于此。
例如:

var errorHandler = function (req, res, next) { .... }
app.use(errorHandler);
k3fezbri

k3fezbri3#

谢谢,我也有同样的问题,我正在使用这样做

app.use(__dirname+'path');

而不是做

app.use(express.static(__dirname+'/path'));

啊!小小的错别字。

2nc8po8w

2nc8po8w4#

适用于在react应用程序中遇到问题的用户

只需从节点模块中删除express并重新安装即可
对于在您正在使用的项目目录中键入您的终端:

npm uninstall express
npm install express

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