无法读取未定义的乘数 属性
cannot read property of undefined multer
我正在创建一个用户 login/registration 来学习 node js express。但是我在上传文件时遇到问题，因为当我提交表单时，控制台说无法读取 属性 'profileimage' of undefined.
我认为问题是我没有正确使用 multer 模块，但正如我所说，我只是 node 的新手。
非常感谢您的帮助，这是代码
app.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var expressValidator=require('express-validator');
var cookieParser = require('cookie-parser');
var session=require('express-session');
var passport=require('passport');
var localStrategy=require('passport-local').strategy;
var bodyParser = require('body-parser');
var multer=require('multer');
var flash =require('connect-flash');
var mongo= require('mongodb');
var mongoose=require('mongoose');
var db=mongoose.connection;
var upload = multer({ dest: 'uploads/' });
var routes = require('./routes/index');
var users = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
//Handle file uploads
app.use(upload.single('file'));
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
//handle epress session
app.use(session({
secret:'secret',
saveUninitialized:true,
resave:true
}));
//passport
app.use(passport.initialize());
app.use(passport.session());
//validator
app.use(expressValidator({
errorFormatter: function(param, msg, value) {
var namespace = param.split('.')
, root = namespace.shift()
, formParam = root;
while(namespace.length) {
formParam += '[' + namespace.shift() + ']';
}
return {
param : formParam,
msg : msg,
value : value
};
}
}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(flash());
app.use(function (req, res, next) {
res.locals.messages = require('express-messages')(req, res);
next();
});
app.use('/', routes);
app.use('/users', users);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
这是使用multer的代码，问题出在if(req.file.profileimage)条件
router.post('/register',function(req,res,next){
//recuperar datos del formulario
var name = req.body.name;
var email = req.body.email;
var username =req.body.username;
var password =req.body.password;
var password2 =req.body.password2;
//revisar input de imagen
if(req.file.profileimage){
console.log('Uploading File..');
var profileimageOriginalName =req.files.profileimage.originalname;
var profileImageName =req.files.profileimage.name;
var profileImageMime =req.files.profileimage.mimeType;
var profileImagePath =req.files.profileimage.path;
var profileImageExt =req.files.profileimage.extension;
var profileImageSize =req.files.profileimage.size;
}else{
//set defaut
var profileImageName='noimage.png';
}
//validacion forma
req.checkBody('name','Name field is required').notEmpty();
req.checkBody('email','Email field is required').notEmpty();
req.checkBody('email','mail not valid').isEmail();
req.checkBody('username','Userame field is required').notEmpty();
req.checkBody('password','Password field is required').notEmpty();
req.checkBody('password2','Passwords dont match').equals(req.body.passowrd);
//revisando errores
var errors= req.validationErrors();
if(errors){
res.render('register',{
errors:errors,
name:name,
email:email,
username:username,
password:password,
password2:password2
});
}else{//cuando los datos son válidos
var newUser= new User({
errors:errors,
name:mame,
email:email,
username:username,
password:password,
profileimage:profileImageName
});
User.createUser(newUser,function(err,user){
if(err) throw err;
console.log(user);
});
req.flash('success','your are redy');
res.location('/');
res.redirect('/');
}
});
这是翡翠形态
form(method='post',action='/users/register',enctype='multipart/form-data')
.form-group
label Name
input.form-control(name='name', type='text',placeholder='Enter Name')
.form-group
label Email
input.form-control(name='email', type='email',placeholder='Enter Email')
.form-group
label Username
input.form-control(name='username', type='text',placeholder='Username')
.form-group
label Password
input.form-control(name='password', type='password',placeholder='Enter Password')
.form-group
label Confirm Password
input.form-control(name='password2', type='password',placeholder='Confirm Password')
.form-group
label Profile Image
input.form-control(name='profileimage', type='file')
input.btn.btn-default(name='submit', type='submit',value='Register')
正如我所说，我确定问题出在 multer 上，但我不知道如何解决它，因为 jade 文件中的名称属性与 users.js 相同。我还检查了 Multer 文档，但我无法自行修复。
谢谢你的帮助:)
当您使用 upload.single() 时，您只使用 req.file 而不是 req.file.profileimage 因为输入字段名称 (profileimage) 是已知的（它被传递给 upload.single()).这意味着您还需要将文件字段 name 属性从 profileimage 更改为 file 或更改传递给 upload.single().
的名称
我还应该补充一点，multer 中间件通常是在路由处理程序级别添加的，因为字段名称通常会有所不同。因此，要以这种方式解析请求，您需要删除 app.use(upload.single('file')) 并将路由处理程序行更改为：
router.post('/register',function(req,res,next){
至：
router.post('/register', upload.single('profileimage'), function(req,res,next){
我正在创建一个用户 login/registration 来学习 node js express。但是我在上传文件时遇到问题，因为当我提交表单时，控制台说无法读取 属性 'profileimage' of undefined.
我认为问题是我没有正确使用 multer 模块，但正如我所说，我只是 node 的新手。
非常感谢您的帮助，这是代码
app.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var expressValidator=require('express-validator');
var cookieParser = require('cookie-parser');
var session=require('express-session');
var passport=require('passport');
var localStrategy=require('passport-local').strategy;
var bodyParser = require('body-parser');
var multer=require('multer');
var flash =require('connect-flash');
var mongo= require('mongodb');
var mongoose=require('mongoose');
var db=mongoose.connection;
var upload = multer({ dest: 'uploads/' });
var routes = require('./routes/index');
var users = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
//Handle file uploads
app.use(upload.single('file'));
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
//handle epress session
app.use(session({
secret:'secret',
saveUninitialized:true,
resave:true
}));
//passport
app.use(passport.initialize());
app.use(passport.session());
//validator
app.use(expressValidator({
errorFormatter: function(param, msg, value) {
var namespace = param.split('.')
, root = namespace.shift()
, formParam = root;
while(namespace.length) {
formParam += '[' + namespace.shift() + ']';
}
return {
param : formParam,
msg : msg,
value : value
};
}
}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(flash());
app.use(function (req, res, next) {
res.locals.messages = require('express-messages')(req, res);
next();
});
app.use('/', routes);
app.use('/users', users);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
这是使用multer的代码，问题出在if(req.file.profileimage)条件
router.post('/register',function(req,res,next){
//recuperar datos del formulario
var name = req.body.name;
var email = req.body.email;
var username =req.body.username;
var password =req.body.password;
var password2 =req.body.password2;
//revisar input de imagen
if(req.file.profileimage){
console.log('Uploading File..');
var profileimageOriginalName =req.files.profileimage.originalname;
var profileImageName =req.files.profileimage.name;
var profileImageMime =req.files.profileimage.mimeType;
var profileImagePath =req.files.profileimage.path;
var profileImageExt =req.files.profileimage.extension;
var profileImageSize =req.files.profileimage.size;
}else{
//set defaut
var profileImageName='noimage.png';
}
//validacion forma
req.checkBody('name','Name field is required').notEmpty();
req.checkBody('email','Email field is required').notEmpty();
req.checkBody('email','mail not valid').isEmail();
req.checkBody('username','Userame field is required').notEmpty();
req.checkBody('password','Password field is required').notEmpty();
req.checkBody('password2','Passwords dont match').equals(req.body.passowrd);
//revisando errores
var errors= req.validationErrors();
if(errors){
res.render('register',{
errors:errors,
name:name,
email:email,
username:username,
password:password,
password2:password2
});
}else{//cuando los datos son válidos
var newUser= new User({
errors:errors,
name:mame,
email:email,
username:username,
password:password,
profileimage:profileImageName
});
User.createUser(newUser,function(err,user){
if(err) throw err;
console.log(user);
});
req.flash('success','your are redy');
res.location('/');
res.redirect('/');
}
});
这是翡翠形态
form(method='post',action='/users/register',enctype='multipart/form-data')
.form-group
label Name
input.form-control(name='name', type='text',placeholder='Enter Name')
.form-group
label Email
input.form-control(name='email', type='email',placeholder='Enter Email')
.form-group
label Username
input.form-control(name='username', type='text',placeholder='Username')
.form-group
label Password
input.form-control(name='password', type='password',placeholder='Enter Password')
.form-group
label Confirm Password
input.form-control(name='password2', type='password',placeholder='Confirm Password')
.form-group
label Profile Image
input.form-control(name='profileimage', type='file')
input.btn.btn-default(name='submit', type='submit',value='Register')
正如我所说，我确定问题出在 multer 上，但我不知道如何解决它，因为 jade 文件中的名称属性与 users.js 相同。我还检查了 Multer 文档，但我无法自行修复。
谢谢你的帮助:)
当您使用 upload.single() 时，您只使用 req.file 而不是 req.file.profileimage 因为输入字段名称 (profileimage) 是已知的（它被传递给 upload.single()).这意味着您还需要将文件字段 name 属性从 profileimage 更改为 file 或更改传递给 upload.single().
我还应该补充一点，multer 中间件通常是在路由处理程序级别添加的，因为字段名称通常会有所不同。因此，要以这种方式解析请求，您需要删除 app.use(upload.single('file')) 并将路由处理程序行更改为：
router.post('/register',function(req,res,next){
至：
router.post('/register', upload.single('profileimage'), function(req,res,next){