How to access file in FormData in multer

Question

I am trying to upload file from a react front-end with fetch to node.js backend with multer. Below is my fetch code:

submitpost=(e)=>{
        e.preventDefault();
        var data=new FormData();
        data.append('file',this.state.shareImage)
        fetch("http://localhost:8080/post", {
             method: 'POST',
             body: data
        }).then((response) =>  {
           console.log(response.json());
        })
    }

The image is in the state of the component. Below is the server code:

const express=require('express')
const app=express()
const bodyParser=require('body-parser')
const multer=require('multer')
const cors=require('cors')

app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
app.use(express.json());
app.use(express.urlencoded());
app.use(cors());

var storage1 = multer.diskStorage({
    destination: function (req, file, cb) {

        // Uploads is the Upload_folder_name
        cb(null, "images")
    },
    filename: function (req, file, cb) {
    cb(null, file.fieldname + "-" + Date.now()+".jpg")
    }
})

const upload = multer({
    storage: storage1
})
app.post('/post',upload.single('myfile'),(req,res)=>{
    console.log(req.body);
    res.send(JSON.stringify({'status':'success'}))
})


app.listen(8080,function(error) {
    if(error) throw error
        console.log("Server created Successfully on PORT 8080")
})

When I see in the console, req.body is empty. This is how my input looks like:

<input type="file" 
                                accept="image/*" 
                                name="myfile"
                                id="file"
                                style={{display: 'none'}}
                                onChange={(event)=>{this.handleChange(event)}} 
                                />

Below is the Request Headers as seen in network tab:

Accept: */*
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9,hi;q=0.8
Connection: keep-alive
Content-Length: 135326
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryE9U4gJpcqK2hAdXC
Host: localhost:8080
Origin: http://localhost:3000
Referer: http://localhost:3000/
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

My question is if this is the correct way to receive files. If yes, why req.body is empty?

Please help me to find the problem.

Thank You!

Answer 1

The code currently initializes the multer middleware, but does not use it. According to the documentation , here's how you'd use it:

app.post("/post", upload.single("file"), (req, res) => {
  // "file" is the name of the field which contains the file

  // req.file is the `avatar` file
  // req.body will hold the text fields, if there were any
  console.log(req.file);
  console.log(req.body);
  res.send(JSON.stringify({ status: "success" }));
});

As an additional side-note, express has a helper for working with JSON. You can replace res.send(JSON.stringify(...)) with res.json(...) :

app.post("/post", upload.single("file"), (req, res) => {
  // "file" is the name of the field which contains the file

  // req.file is the `avatar` file
  // req.body will hold the text fields, if there were any
  console.log(req.file);
  console.log(req.body);
  res.json({ status: "success" });
});