How to Upload Files in Node.js using Multer

In a Node.js application, if there is a requirement to upload files to the server Multer is a good option. It can be used in any JavaScript backend. For this article, we will use Express.

Multer is a Node.js middleware for handling multipart/form-data

Ways to use Multer:

There are multiple ways to use Multer:

1. We upload files directly to the Node server (in a server)

2. Saving file data or base64 data in a database

3. Save AWS S3 bucket to save and manage files (using a service)

In this article, we will save files directly to the server.

Setting up Express application:

→ We need to install the basic express setup using the below command

express <your_app_name> --view=ejs

→ Run the below command in the express root directory for installing Multer:

npm i multer

STEP1: Create Routes:

We can upload a single file as well as multiple files.

var express = require("express");
var router = express.Router();
const upload = require("../common");
/* GET home page. */
router.get("/", function (req, res, next) {
  res.render("index", { title: "Express" });
});
// Single file Upload - image key should be passed postman
router.post("/single", upload.single("image"), (req, res, next) => {
  console.log(req.file);  // UPLOADED FILE DESCRIPTION RECEIVED
  res.send("uploaded successfully");
});
// Multiple files Upload - images key should be passed in postman
router.post("/multiple", upload.array("images"), (req, res) => {
  console.log(req.files); // UPLOADED FILE DESCRIPTION RECEIVED
  res.send({
    status: "success",
    message: "Files uploaded successfully",
    data: req.files,
  });
});
module.exports = router;

common.js (Handling upload functionality)

→ Here we write the logic for uploading files

const multer = require("multer");
var fs = require("fs");
var dir = "./public/images/nov";   // PATH TO UPLOAD FILE
if (!fs.existsSync(dir)) {  // CREATE DIRECTORY IF NOT FOUND
  fs.mkdirSync(dir, { recursive: true });
}
const fileStorageEngine = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, dir);
  },
  filename: (req, file, cb) => {
    cb(null, Date.now() + "-" + file.originalname);
  },
});
const upload = multer({ storage: fileStorageEngine });
module.exports = upload;

→ Run the Node server using the below command

npm start

→ We will use Postman for importing files. You can follow below screenshots and videos for Postman

Route: http://localhost:5000/single

Type: POST

Body: form-data, select key as image of type File

→ We get the file name and path where the file is saved. Let us now go to the below path in our codebase.

→ We have successfully uploaded the file

→ Let us now do multiple uploads using our second route:

Route: http://localhost:5000/multiple

Type: POST

Body: form-data, select key as images of type File

→ We get an array of images along with filename and path

→ Let us check the file in the codebase

Video:

https://secure.vidyard.com/organizations/1904214/players/Qr56rBG9FMtqB1SrETx2ut?edit=true&npsRecordControl=1

Repository:

https://github.com/AmirMustafa/export-to-excel

Closing Thoughts:

We have learnt how we can upload files directly in Node.js. We can also upload files in the AWS S3 bucket and upload base 64 data in the database.

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