app.use的multer配置返回TypeError

Question

我正在尝试在我的app.js文件中配置multer(使用node.js/express)以允许用户上传图像.我在app.js中有以下代码:

//various require statements for passport, cookie parser, etc..

var multer = require('multer');

var app = express();

app.use(multer({dest:'./uploads/'}));

当我尝试运行应用程序时,我得到了 TypeError: app.use() requires middleware functions

我了解这些问题可能需要更多关于我的应用程序的上下文,所以如果需要其他信息,请告诉我.

谢谢

编辑:来自app.js的更多代码:

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var bodyParser = require('body-parser');
var methodOverride = require('method-override');
var session = require('express-session');
//var fs = require('fs');
var multer = require('multer');

//Mongo Database
var mongo = require('mongodb');
var monk = require('monk');
var db = monk('localhost:27017/test-api');

//Instagram-API
var api = require('instagram-node').instagram();

//Cookie Manager
var cookieParser = require('cookie-parser');

//Grid
//var Grid = require('gridfs-stream');

//Passport
var passport = require('passport');
var InstagramStrategy = require('passport-instagram').Strategy;

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');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(multer({dest:'./uploads/'}));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(methodOverride());
app.use(session({secret: 'keyboard cat', resave: false, saveUninitialized: true }));
app.use(passport.initialize());
app.use(passport.session());
app.use(express.static(path.join(__dirname, 'public')));


// Make our db accessible to our router
app.use(function(req,res,next){
    req.db = db;
    next();
});

app.use('/', routes);

Answer 1

问题是multer({dest:'./uploads/'})返回对象,而不是中间件功能.如果我们看一下代码模块,我们会看到有三个middlware函数:

multer({dest:'./uploads/'}).single(...)
multer({dest:'./uploads/'}).array(...)
multer({dest:'./uploads/'}).fields(...)

尝试其中一个.

Answer 2

归功于@ stdob--指导我朝着正确的方向前进.我正在查看的multer文档似乎在我工作时已经更新,因此我错误地使用了代码.

Multer应该与其中间件功能一起使用.因此,使用此包的正确方法如下:

var multer = require('multer');

var upload = multer({dest:'uploads/'});

var cpUpload = upload.single('postImg');

router.post('/createpost', cpUpload, function(req,res){

  console.log(req.file);
  res.redirect('/');

}

此代码段将为'/ createpost'创建一个发布路径,并将单个文档(通过表单名称'postImg')上传到服务器中的/ uploads.req.file包含带有文件信息的JSON(例如文件路径).请记住,这不会自动删除上传的文件.

更多信息可以在这里找到:https://www.npmjs.com/package/multer

Answer 3

这会做

app.use(multer({dest:'./public/images/uploads'}).any());