Typeerror: Cannot read Property 'filename' of Undefined

Question

I intend to store the file in the folder uploads and secure in the bank the name of the file. The console.log() show me this:

{theBook: undefined, cover: undefined}

Stores the image in the folder uploads but don’t file the name in the comic book, coming as Undefined.

'Cause I’m getting this result?:

Typeerror: Cannot read Property 'filename' of Undefined

---

My file:

eBook.js

const express = require("express");
const router = express.Router();
const mongoose = require("mongoose");
const User = mongoose.model('users');
const requireDir = require('require-dir');
requireDir('../models');
const eBook = mongoose.model('books');
const multer = require('multer');
const uploadConfig = require('../config/upload');

const upload = multer(uploadConfig);
var eBookUpload = upload.fields([
{ name: 'cover', maxCount: 1 }, 
{ name: 'theBook', maxCount: 1 }
]);

router.post('/add', eBookUpload, async (req, res, next) => {
    var erros = []

    if(!req.body.title || typeof req.body.title == undefined || req.body.title == null){
        erros.push({texto: "Título inválido"})
    }

    if(!req.body.author || typeof req.body.author == undefined || req.body.author == null){
        erros.push({texto: "Autor inválido"})
    }

    if(erros.length > 0){
        res.render("pages/ebooks/create", {erros: erros})
    }else{
        const filename = req.file.filename;
        const newBook = {
            title: req.body.title,
            author: req.body.author,
            genre: req.body.genre,
            publisher: req.body.publisher,
            edition: req.body.edition,
            isbn: req.body.isbn,
            pages: req.body.pages,
            theBook: filename,
            cover: filename,
            type: req.body.type,

        }
        new eBook(newBook).save().then(function(){
            req.flash("success_msg", "eBook adicionado com sucesso!")
            res.redirect("/ebook/galeria")
            console.log(newBook)
        }).catch(function(err){
            console.log(err)
            req.flash("error_msg", "Houve um erro ao salvar o eBook! Tente novamente")
            res.redirect("/ebook/galerias")
        })
    }
});

Answer 1

The problem is that you have an array of files, so it would be:

const filename = req.files[index].filename;

Answer 2

After many weeks of research, I finally managed to solve the problem. The solution is simple req.files[nome-do-campo][0].filename... This way the implementation would look like this:

router.post('/add', accessControl, fileBook, async (req, res, next) => {
var erros = []

    if(!req.body.title || typeof req.body.title == undefined || req.body.title == null){
        erros.push({texto: "Título inválido"})
    }

    if(!req.body.author || typeof req.body.author == undefined || req.body.author == null){
        erros.push({texto: "Autor inválido"})
    }

    if(erros.length > 0){
        res.render("pages/ebooks/create", {erros: erros})
    }else{
        //const { filename } = req.file;
        const newBook = {
            title: req.body.title,
            preface: req.body.preface,
            author: req.body.author,
            genre: req.body.genre,
            publisher: req.body.publisher,
            edition: req.body.edition,
            isbn: req.body.isbn,
            pages: req.body.pages,
            cover: req.files['cover'][0].filename,
            theBook: req.files['theBook'][0].filename,
            type: req.body.type,
            tags: req.body.tags

        }
        new eBook(newBook).save().then(function(){
            req.flash("success_msg", "eBook adicionado com sucesso!");
            res.redirect("/ebook/biblioteca");
            console.log(newBook);
        }).catch(function(err){
            console.log(err);
            req.flash("error_msg", "Houve um erro ao salvar o eBook! Tente novamente");
            res.redirect("/ebook/biblioteca");
        });
    }});

Answer 3

Horacio, the example below is a code that I wrote a while ago and that works correctly. I removed some points that are not part of the understanding. Another point is that if working with Array the files must be accessed through the req.files instead of req.file:

exports.post = async (req, res) => {
    var multer = null;
    try {
        multer = require('multer');
    } catch (ex) {
        // TODO console.error(ex);
        // TODO return res.json();
    }

    var upload = null;
    try {
        var path = require('path');
        var storage = multer.diskStorage({
            destination: function (req, file, cb) {
                // process.env.DIRETORIOUPLOAD = diretório
                // onde o arquivo será salvo
                cb(null, process.env.DIRETORIOUPLOAD);
            },
            filename: function (req, file, cb) {
                fileExtension = file.originalname.split('.')[1];

                // Não faz parte da questão mas estou dando um novo nome para o arquivo
                // físico
                const novoNome = require('crypto').randomBytes(64).toString('hex');
                cb(null, novoNome + path.extname(file.originalname));
            }
        });

        upload = multer({ storage: storage }).fields([
            // O name do input deve ser "anexo"
            { name: 'anexo', maxCount: 1 }
        ]);
    } catch (ex) {
        // TODO console.error(ex);
        // TODO return res.json();
    }

    upload(req, res, async err => {
        if (err) {
            // TODO console.error(ex);
            // TODO return res.json();
        }

        var obj = {
            // Informações postadas além do anexo
            campo1: req.body.campo1,
            campo2: req.body.campo2,

            // Novo nome do arquivo atribuído mais acima
            nomeArquivo: req.files['anexo'][0].filename,
            extensao: req.files['anexo'][0].filename.split('.')[1],

            // Nome original do arquivo
            nomeOriginal: req.files['anexo'][0].originalname,
            mimetype: req.files['anexo'][0].mimetype
        };

        // TODO salvar o "obj" no DB
        // TODO res.json();
    });
}

More details about the documentation: https://github.com/expressjs/multer