javascript - servidor - npm express

typeerror: app.use() requiere una función de middleware

Question

Estoy aprendiendo node.js con el motor de plantillas express, estoy siguiendo el curso de udemy "aprende node.js construyendo 10 proyectos", mientras npm start localhost:3000 una conferencia cuando el profesor ejecuta npm start localhost:3000 inicia mientras que el mío aparece un error que indica que app.use requiere Función middleware He intentado emparejar código y su mismo. Por favor, ayúdeme a resolver el error. He estado atascado aquí durante horas. Intenté muchas ediciones, pero no me funcionó.

Cuando intento ejecutar ''npm start'' aparece un error emergente

TypeError: app.use () requiere funciones de middleware

Aquí está el código 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 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(multer({
  dest: ''./uploads''
}));

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + ''/public/favicon.ico''));
app.use(logger(''dev''));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: false
}));

//Handle Express Sessions
app.use(session({
  secret: ''secret'',
  saveUninitialied: 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;

Aquí está el archivo package.json

{
  "name": "nodeauth",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "body-parser": "~1.12.4",
    "cookie-parser": "~1.3.5",
    "debug": "~2.2.0",
    "express": "~4.12.4",
    "jade": "~1.9.2",
    "morgan": "~1.5.3",
    "serve-favicon": "~2.2.1",
    "mongodb": "*",
    "mongoose": "*",
    "connect-flash": "*",
    "express-validator": "*",
    "express-session": "*",
    "express-messages": "*",
    "passport": "*",
    "passport-local": "*",
    "passport-http": "*",
    "multer": "*"
  }
}

Aquí se actualiza app.js (después de eliminar multar)

var express          = require(''express''),
    path             = require(''path''),
    favicon          = require(''serve-favicon''),
    logger           = require(''morgan''),
    cookieParser     = require(''cookie-parser''),
    expressValidator = require(''express-validator''),
    session          = require(''express-session''),
    passport         = require(''passport''),
    LocalStrategy    = require(''passport-local'').Strategy,
    bodyParser       = require(''body-parser''),
    flash            = require(''connect-flash''),
    mongo            = require(''mongodb''),
    mongoose         = require(''mongoose''),

    db = mongoose.connection,

    routes = require(''./routes/index''),
    users  = require(''./routes/users''),

    app = express();

// view engine setup
app.set(''views'', path.join(__dirname, ''views''));
app.set(''view engine'', ''jade'');

// handle file uploads

//multer delted


// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + ''/public/favicon.ico''));
app.use(logger(''dev''));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

// handle express sessions
app.use(session({
  secret: ''keyboard cat'',
  resave: true,
  saveUninitialized: 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'')));

// flash
app.use(flash());

// express messages
app.use(function(req, res, next) {
  res.locals.messages = require(''express-messages'')(req, res);
  next();
});

app.get(''*'', function(req, res, next) {
  res.locals.user = req.user || null;
  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: {}
  });
});


//Express server
var http = require(''http'');
var server = http.createServer(app);

app.get(''/'', function(req, res) {
    res.send("Hello World!");
});

server.listen(3000, ''localhost'');
server.on(''listening'', function() {
    console.log(''Express server started on port %s at %s'', server.address().port, server.address().address);
});

module.exports = app;

Gracias

Answer 1

Cambio:

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

Para algo como:

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

o

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

Y ten en cuenta que tienes algo como:

<form action="/postPhotos" enctype="multipart/form-data">
    <input type="file" name="singleInputFileName">
    <input type="submit" value="Upload photo">
</form>

para el primer caso, o

<form action="/postPhotos" enctype="multipart/form-data">
    <input type="file" name="multiInputFileName" multiple>
    <input type="submit" value="Upload photo">
</form>

Para el segundo, en tu html.

Answer 2

Esto funcionó conmigo:

app.use(multer({
  dest: path.join(__dirname, ''public/upload/temp'')
}).any());

Answer 3

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

a

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

trabajó para mi.

Answer 4

También estaba haciendo ese curso y me encontré con el mismo problema. Resolví el error siguiendo las instrucciones de uso de Multer de su github: https://github.com/expressjs/multer

Aquí está el código de su README:

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

Y aquí está el código que utilicé para superar el error al hacer ese tutorial:

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

Espero eso ayude :)

Answer 5

cambiar solo esta linea

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

a

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

Answer 6

simplemente puede utilizar:

app.set(multer({dest: "./uploads"}));

funciona para mi tambien

Answer 7

Funcionó de esta manera. borra esta línea,

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

y usarlo como,

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

Yo también estoy siguiendo el mismo curso