CODEWITHSUNDEEP
node.jsexpressmulter
Gery Ruslandi
Gery Ruslandi

Reputation: 109

Why use multer rather than manually upload your files from controller

So im new on using expressjs, usually i choose Laravel as my backend. but because some certain consideration, i choose expressjs.

On Laravel, when we handling file upload, we can write upload logic everywhere, its your freedom to do that. You can encapsulate it inside your model function, or put it on service, or anywhere you want.

But when i use expressjs, so many articles on internet that recommend us to use multer for upload your file. As my background is using Laravel previously, i found its weird to use multer. Its because multer is a middleware. Why on earth we use middleware to upload our images/files.

With this i cant encapsulate my business logic into one service and its make the code separated and with this thats mean i need to maintain one business logic from multiple place. Could you explain me why everyone choose multer ?

why dont just upload it to our local storage manually ?( actually for now i dont know how to do this ). What is pros on mins from using this library ?

Upvotes: 5

Views: 12192

Answers (2)

thammada.ts
thammada.ts

Reputation: 5245

multer is a body parsing middleware that handles content type multipart/form-data

That means it parses the raw http request data which are primarily used for file upload, and makes it more accessible (storing on disk / in memory /...) for further processing.

Without multer, you would have to parse the raw data yourself if you want to access the file.

With this i cant encapsulate my business logic into one service and its make the code separated and with this thats mean i need to maintain one business logic from multiple place. Could you explain me why everyone choose multer ?

multer, just like other middlewares, can be used at the root for all routes, but can also be put on only specific routes too.

More on express middleware

Upvotes: 2

Jason Roman
Jason Roman

Reputation: 8276

First of all, Express/body-parser does not handle file uploads natively, so that is why you see other libraries being loaded to handle them. They are all going to be loaded as middleware so they can be injected into the request and handle that a file was actually uploaded.

Coming from a Symfony background, I understand where you are coming from with wanting to handle things more manually, as I do the same. There are other alternatives to multer; for example I use express-fileupload which allows you to load the the uploading middleware for your entire app, and then you can use req.files to handle your uploads. For example:

// load the file upload library as app middleware
const fileUpload = require('express-fileupload');

app.use(fileUpload({
  limits: { fileSize: 50 * 1024 * 1024 },
}));

Then let's say you have a file input named 'foo':

<input name="foo" type="file" />

In your route you would handle it like so:

// now handle a file upload
app.post('/upload', function(req, res) {
  console.log(req.files.foo); // the uploaded file object
});

The file-upload documentation has examples for the req.files object as well as options you can pass to the middleware itself.

Upvotes: 1

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