I'm building an application that allows the user to upload and download files. The issue i'm currently having is that I can retrieve the file from my MongoDB database and download it locally through my machine, but I can't get it to download through the browser.
So far I have tried doing it like this
const conn = mongoose.createConnection(process.env.URL, {
useNewUrlParser: true,
useUnifiedTopology: true
})
const bucket = new GridFSBucket(conn, {bucketName: 'uploads'});
router.get('/download', (req, res) => {
const files = bucket.openDownloadStreamByName('3987a162969935378c4f8cbe5d95bb46.svg').pipe(fs.createWriteStream('./3987a162969935378c4f8cbe5d95bb46.svg'))
res.end()
})
If we want to send file directly to client without writing to disk, use this:
backend
router.get('/download', (req, res) => {
res.set('Content-disposition', `attachment; filename="your_file_name.svg"`);
res.set('Content-Type', 'image/svg+xml');
bucket.openDownloadStreamByName('your_file_name.svg').pipe(res);
})
frontend
fetch('http://localhost:8000/download')
.then(res => res.blob())
.then(data => {
saveAs(data, 'your_file_name.svg');
})
I do not think the issue is with mongoDB or Gridfs its how you are dealing with the file stream. If you want the file to be downloaded once the user calls /GET /download you need to
use - res.download(file); e.g.
const conn = mongoose.createConnection(process.env.URL, {
useNewUrlParser: true,
useUnifiedTopology: true
})
const bucket = new GridFSBucket(conn, {
bucketName: 'uploads'
});
router.get('/download', (req, res) => {
const files = bucket.openDownloadStreamByName('3987a162969935378c4f8cbe5d95bb46.svg').pipe(fs.createWriteStream('./3987a162969935378c4f8cbe5d95bb46.svg'))
res.download(files)
})
Good Luck!
Also visit this Download a file from NodeJS Server using Express
Related
I am working on a web app project and for which i need to authenticate the user for some protected routes so i am using jwt tokens for this need.
Technologies used in project :-
frontend --> react
backend --> node, express
Node JS backend code.
const express = require('express');
const app = express();
const ProductModel = require('../Schemas/productSchema')
const product = ProductModel;
app.get('/', (req, res) => {
try {
product.find(function(err, data){
if(data){
res.cookie("test", "test1");
res.send(data);
}
else{
res.json({message : err});
}
})
} catch (error) {
res.json({message : error});
}
})
React frontend code.
here in this frontend code i am making a get request to the server using fetch
useEffect(() => {
async function fetchData(){
await fetch('http://localhost:5000/products')
.then(res => res.json())
.then(data =>{
// setProducts(data.data);
})
.catch(err => console.log(err))
}
fetchData();
}, [])
In the nodejs code i am sending cookie to the browser and for good the cookie is getting shown in the chrome devtool network
But cookie is not getting shown up in the browser->devtool->application->cookies
I don't know why this happening please submit the solutions with explanation.
First, I guess that u need to import the cookie parser
const cookieParser = require('cookie-parser')
app.use(cookieParser());
this lets you use the cookieParser in your application
And finally u can use it :
res.cookie(`...`);
I'm trying to upload an image (jpg/jpeg/png) from the browser to NodeJS. I have read through several tutorials and many posts on forums but very few seem to have this specific issue.
I've made sure to match the name provided to multer (upload.single('upload')) with the formData key (formData.append('upload', selectedFile, selectedFile.name))
I tried using headers originally, but later read that I should exclude them.
I tried submitting through a <form action="/upload" method="post" enctype="multipart/form-data"> but still got the same error.
I have found this similar question with only one answer which isn't clear
Multer gives unexpetcted end of form error and this question Unexpected end of form at Multipart._final which has no answers.
Every other question seems to be about an 'Unexpected field' or 'Unexpected end of multipart data' error which - judging from the solutions - is irrelevant here.
Below is my code...
Browser:
<body>
<input type="file" id="file_uploader" name="upload" />
<button onclick="uploadImage()" class="btn-default">SUBMIT</button>
<!-- OTHER STUFF -->
</body>
<script>
let selectedFile;
let uploadData = new FormData();
const fileInput = document.getElementById('file_uploader');
fileInput.onchange = () => {
selectedFile = fileInput.files[0];
uploadData.append('upload', selectedFile, selectedFile.name);
}
function uploadImage(){
fetch('/upload', {
method: 'POST',
body: uploadData
})
.then((response) => {
console.log(response);
})
.catch((error) => {
console.error('Error: ', error);
});
}
</script>
NodeJS
let express = require('express');
const multer = require('multer');
//multer options
const upload = multer({
dest: './upload/',
limits: {
fileSize: 1000000,
}
})
const app = express();
app.post('/upload', upload.single('upload'), (req, res) => {
res.send();
}, (error, req, res, next) => {
console.log(error.message);
})
exports.app = functions.https.onRequest(app);
...And here is the error log, if it helps:
Error: Unexpected end of form
> at Multipart._final (C:\Users\p\Downloads\MyInvestmentHub\functions\node_modules\busboy\lib\types\multipart.js:588:17)
> at callFinal (node:internal/streams/writable:694:27)
> at prefinish (node:internal/streams/writable:723:7)
> at finishMaybe (node:internal/streams/writable:733:5)
> at Multipart.Writable.end (node:internal/streams/writable:631:5)
> at onend (node:internal/streams/readable:693:10)
> at processTicksAndRejections (node:internal/process/task_queues:78:11)
I haven't posted many questions as of yet, so I apologise if I'm missing something or the format is off. Let me know and I will make appropriate edits.
Thanks.
I also got the exact same error.
Before using multer I had installed express-fileupload. When I unistalled it using the command npm uninstall express-fileupload I could get rid of the error.
And if it is the same case with you don't forget to delete the commands you already added for express-fileupload module. (like requiring fileupload)
Hi there I ran into the same issue for me was the lack of a bodyParser middleware that allows our requests files to parsed into Buffers.
I was able to resolve the problem like so in express:
var bodyParser = require('body-parser')
bodyParser.json([options])
I had this problem using multer with next js api. What worked for me is, I exported an a config that sets bodyParser to false like so;
export const config = {
api: {
bodyParser: false
}
}
In my case, the cause was other middleware. Check for other middleware running before multer. For me, the issue was express-openapi-validator middleware. Once I removed that middleware, it worked as expected.
Using body-parser package worked for me:
const bodyParser = require('body-parser')
// ...
app.use(bodyParser()) // support encoded bodies
My upload single file route:
const multer = require('multer')
const express = require('express')
const router = express()
const path = require('path') // node built-in path package
// needs "app.use(bodyParser())" middleware to work
const storage = multer.diskStorage({
destination: function (req, file, cb) {
cb(null, process.cwd() + '/public/')
},
filename: function (req, file, cb) {
// generate the public name, removing problematic characters
const originalName = encodeURIComponent(path.parse(file.originalname).name).replace(/[^a-zA-Z0-9]/g, '')
const timestamp = Date.now()
const extension = path.extname(file.originalname).toLowerCase()
cb(null, originalName + '_' + timestamp + extension)
}
})
const upload = multer({
storage: storage,
limits: { fileSize: 1 * 1024 * 1024 }, // 1 Mb
fileFilter: (req, file, callback) => {
const acceptableExtensions = ['png', 'jpg', 'jpeg', 'jpg']
if (!(acceptableExtensions.some(extension =>
path.extname(file.originalname).toLowerCase() === `.${extension}`)
)) {
return callback(new Error(`Extension not allowed, accepted extensions are ${acceptableExtensions.join(',')}`))
}
callback(null, true)
}
})
router.post('/api/upload/single', upload.single('file'), (req, res) => {
res.status(200).json(req.file)
})
module.exports = {
uploadRouter: router
}
I think this is may causes by the responsed end,so in your continuous Middleware,you can do upload file at last.
i do this resolve problems.
const upload = multer({
dest: "./uploads",
});
app.use(upload.any());
app.post(
"/upload",
(req, res, next) => {
res.end("文件上传成功");
},
upload.single("fileKey")
);
try using these it work
const express = require('express')
const app = express()
const path = require('path')
const multer = require('multer')
var filestorageEngine = multer.diskStorage({
destination: (req, file, cb) => {
cb(null,'./uploads')
},
filename:(req,file, cb) => {
cb(null,"[maues]-" + file.originalname)
}
})
var upload = multer({
storage:filestorageEngine
})
app.post('/file', upload.array('file', 3),(req, res) => {
console.log(req.file)
res.send("file uploaded successfully")
})
app.listen(5000, ()=> {
console.log("server running")
})
in my frontend or client-side removing the headers in my request. And make sure your inputs are as a formData.
For example:
let formData = new FormData();
formData.append("fileName", file);
const res = await fetch("/api/create-card", {
method: "POST",
body: formData,
})
This worked for me.
I think, the problem is in the express and body-parser module, I just eliminated it
app.use(bodyParser.text({ type: '/' }));
and it works!
Try downgrading Multer to 1.4.3. It worked for me.
See https://github.com/expressjs/multer/issues/1144
I am learning how to upload images from my React website to my Mongo database through an express server. In every tutorial I have read, the author saves the file locally in the express server before sending it to the Mongo database. Is there a way to avoid having to store the file locally by keeping it in a local variable which is then uploaded to the database?
Here are the tutorials I am referring to:
https://www.positronx.io/react-file-upload-tutorial-with-node-express-and-multer/
https://medium.com/ecmastack/uploading-files-with-react-js-and-node-js-e7e6b707f4ef
Thank you for your help.
I guess The GridFS API would be helpful to you.It says :
you can .pipe() directly from file streams to MongoDB
Here is the sample example according to doc :
const assert = require('assert');
const fs = require('fs');
const mongodb = require('mongodb');
const uri = 'mongodb://localhost:27017';
const dbName = 'test';
mongodb.MongoClient.connect(uri, function(error, client) {
assert.ifError(error);
const db = client.db(dbName);
var bucket = new mongodb.GridFSBucket(db);
fs.createReadStream('./meistersinger.mp3').
pipe(bucket.openUploadStream('meistersinger.mp3')).
on('error', function(error) {
assert.ifError(error);
}).
on('finish', function() {
console.log('done!');
process.exit(0);
});
});
documentation link : https://mongodb.github.io/node-mongodb-native/3.0/tutorials/gridfs/streaming/
Hope this help !
yes you want to store you files locally. I used an NFS server (FreeNas) and mounted it to that local folder.
So when i saved a file to that location, it was stored on the other NFS server. Then i sent that image location as a response back to react, which then saved that location in Mongodb.
Example uploads.js
router.post('/', auth, async (req, res) => {
let CurrentDate = moment().unix();
if (req.files.file === null) {
return res.status(400).json({ msg: 'no file uploaded' });
}
let user = await User.findById(req.user.id).select('-password');
let file = req.files.file;
file.name = CurrentDate + user._id + '.jpg';
file.mv(`./client/public/uploads/${file.name}`, (err) => {
if (err) {
console.error(err);
return res.status(500).send(err);
}
res.json({ fileName: file.name, filePath: `/uploads/${file.name}`});
});
});
This is what the mongodb entry looks like
image:"/uploads/15951066675f1365239d46882312332d20.jpg"
I am creating API using express JS. Now, I have a router which will be used to upload image using multer.
Here is my router :
const multer = require('multer');
module.exports = (app) => {
const DIR = './public/';
const storage = multer.diskStorage({
destination: (req, file, cb) => {
cb(null, DIR);
},
filename: (req, file, cb) => {
cb(null , file.originalname);
}
});
const upload = multer({ storage: storage });
// I have also tried this but not working
// const upload = multer({ dest: 'uploads/' });
app.post('/upload', upload.single('image'), (req, res, next) => {
res.status(201).json({
message: "File uploaded successfully"
});
});
}
Now, from my reactjs app I am calling this router using axios like this :
const headers = {
"Content-Type": "multipart/form-data"
}
const body = new FormData();
body.append('image', this.state.selectedCategoryImage);
axios.post('http://localhost:3000/upload', body, { headers }).then((res) => {
console.log(res);
}).catch((err) => {
console.log(err);
});
In above code this.state.selectedCategoryImage is a selected image from html <input> tag.
Now, When I call this api I am getting my response "file uploaded successfully", but I am not able to see my uploaded image anywhere in public directory. My image is not uploading.
Please anyone can help me what's the issue ?
Pass file Object not URL
URL.createObjectURL(file) // it return file url that you can use to show file preview
For upload file, send actual file in axios API as you got from file input
var file = event.target.files[0]; // return actual file
this way it actually send file object.
I am using multer diskstorage to save a file to disk.
I first save it to the disk and do some operations with the file and then i upload it to remote bucket using another function and lib.
Once the upload is finished, i would like to delete it from the disk.
var storage = multer.diskStorage({
destination: function (req, file, cb) {
cb(null, '/tmp/my-uploads')
},
filename: function (req, file, cb) {
cb(null, file.fieldname + '-' + Date.now())
}
})
var upload = multer({ storage: storage }).single('file')
and here is how i use it:
app.post('/api/photo', function (req, res) {
upload(req, res, function (err) {
uploadToRemoteBucket(req.file.path)
.then(data => {
// delete from disk first
res.end("UPLOAD COMPLETED!");
})
})
});
how can i use the diskStorage remove function to remove the files in the temp folder?
https://github.com/expressjs/multer/blob/master/storage/disk.js#L54
update:
I have decided to make it modular and put it in another file:
const fileUpload = function(req, res, cb) {
upload(req, res, function (err) {
uploadToRemoteBucket(req.file.path)
.then(data => {
// delete from disk first
res.end("UPLOAD COMPLETED!");
})
})
}
module.exports = { fileUpload };
You don't need to use multer to delete the file and besides _removeFile is a private function that you should not use.
You'd delete the file as you normally would via fs.unlink. So wherever you have access to req.file, you can do the following:
const fs = require('fs')
const { promisify } = require('util')
const unlinkAsync = promisify(fs.unlink)
// ...
const storage = multer.diskStorage({
destination(req, file, cb) {
cb(null, '/tmp/my-uploads')
},
filename(req, file, cb) {
cb(null, `${file.fieldname}-${Date.now()}`)
}
})
const upload = multer({ storage: storage }).single('file')
app.post('/api/photo', upload, async (req, res) =>{
// You aren't doing anything with data so no need for the return value
await uploadToRemoteBucket(req.file.path)
// Delete the file like normal
await unlinkAsync(req.file.path)
res.end("UPLOAD COMPLETED!")
})
Multer isn't needed. Just use this code.
const fs = require('fs')
const path = './file.txt'
fs.unlink(path, (err) => {
if (err) {
console.error(err)
return
}
//file removed
})
You may also consider using MemoryStorage for this purpose, with this storage the file is never stored in the disk but in memory and is deleted from the memory automatically after execution comes out of controller block, i.e., after you serve the response in most of the cases.
When you will use this storage option, you won't get the fields file.destination, file.path and file.filename, instead you will get a field file.buffer which as name suggests is a buffer, you can convert this buffer to desired format to do operations on and then upload using a stream object.
Most of the popular libraries support streams so you should be able to use stream to upload your file directly, code for converting buffer to stream:
const Readable = require('stream').Readable;
var stream = new Readable();
stream._read = () => { }
stream.push(file.buffer);
stream.push(null);
// now you can pass this stream object to your upload function
This approach would be more efficient as files will be stored in memory which will result in faster access, but it does have a con as mentioned in multer documentation:
WARNING: Uploading very large files, or relatively small files in
large numbers very quickly, can cause your application to run out of
memory when memory storage is used.
To do it truly automatically across all routes I used this strategy :
when the request ends, we delete all the uploaded files (req.files). Before that, if you want to keep the files on the server, you need to save them in another path.
var express = require('express');
var app = express();
var http = require('http');
var server = http.Server(app);
// classic multer instantiation
var multer = require('multer');
var upload = multer({
storage: multer.diskStorage({
destination: function (req, file, cb) {
cb(null, `${__dirname}/web/uploads/tmp/`);
},
filename: function (req, file, cb) {
cb(null, uniqid() + path.extname(file.originalname));
},
}),
});
app.use(upload.any());
// automatically deletes uploaded files when express finishes the request
app.use(function(req, res, next) {
var writeHead = res.writeHead;
var writeHeadbound = writeHead.bind(res);
res.writeHead = function (statusCode, statusMessage, headers) {
if (req.files) {
for (var file of req.files) {
fs.unlink(file.path, function (err) {
if (err) console.error(err);
});
}
}
writeHeadbound(statusCode, statusMessage, headers);
};
next();
});
// route to upload a file
router.post('/profile/edit', access.isLogged(), async function (req, res, next) {
try {
// we copy uploaded files to a custom folder or the middleware will delete them
for (let file of req.files)
if (file.fieldname == 'picture')
await fs.promises.copy(file.path, `${__dirname}/../uploads/user/photo.jpg`);
} catch (err) {
next(err);
}
});
I have removed directory after file uploaded using fs-extra
const fs = require('fs-extra');
// after you uploaded to bucket
await fs.remove('uploads/abc.png'); // remove upload dir when uploaded bucket