jsPDF saving the file without extension when sent to nodejs/expressjs server - node.js

I have a class based react component that takes data from a user. The data is then fed to jsPDF.
let doc = new jsPDF();
doc.save()
This works fine. It saves the file with .pdf extension.
Now the problem is that I am sending this file to the express.js backend.
const pdf = new Blob([this.state.doc.output("blob")], {
type: "application/pdf",
});
OR
const pdf = this.state.doc.output("blob");
NODE.js
I am using Formidable.js for receiving the file.
const newPath = files.pdf.path;
The file gets saved without an extension.
I also did this
const newPath = `${files.pdf.path}.pdf`
This adds the .pdf to the string that is saved to mongodb, but the file saved is without any extension.

Solved.
https://github.com/node-formidable/formidable/issues/680
//front-end
const pdf = new File([doc.output("blob")], "myDoc.pdf", {
type: "application/pdf",
});
//Node
const newPath = files.pdf.path;
Thanks to https://github.com/GrosSacASac

Related

Storing and downloading pdf files from mongoDB using Node.js

I am using NodeJs, mongoose, ejs
I want the user to be able to upload his CV (Less the 16 MB) as a pdf file, then the admin to be able to download the pdf or view the CV on the website.
I did the upload part where I stored the cv like this in the database (which might be a wrong way):
cv: Object {
fileName: "Test Results All in testing-homework.pdf"
filePath: "cvs\1650985306448-.pdf"
fileType: "application/pdf"
}
and the pdf file is stored in the "/cvs" folder after upload.
I'm seeking a way to be able to download/view the pdf file from the database.
I will suggest you to use GridFs from mongodb.
refer:https://www.mongodb.com/docs/drivers/node/current/fundamentals/gridfs/
To Download from DB
bucket.openDownloadStreamByName('your_file_name').
pipe(fs.createWriteStream('./desired_name_of_output_file'));
Some of the Basic Upload and Download Operations using GridFs in MongoDB
const mongoUrl='mongodb://127.0.0.1:27017/db'
const mongodb = require('mongodb');
const fs = require('node:fs');
const client = new mongodb.MongoClient(mongoUrl)
const db = client.db('db');
Create Bucket with user-defined name
const bucket = new mongodb.GridFSBucket(db,{bucketName:'name_of_bucket' });
Upload to DB
fs.createReadStream('./filename.pdf').
pipe(bucket.openUploadStream('filename', {
chunkSizeBytes: 1048576,
metadata: { field: 'filename', value: 'myValue' }
}))
Find
const cursor = bucket.find({});
cursor.forEach(doc => console.log(doc));
Delete
cursor.forEach(doc => bucket.delete(doc._id));

Serve clickable download URL in NodeJS

At my endpoint in my NodeJS server, after retrieving an audio file stored as a Buffer in MongoDB, I want to represent it with a URL (much like how you do with URL.createObjectURL(blob) in the frontend on the browser). I then plan to res.render() the URL in HTML through Handlebars on the client, so that the user can click on it to download it:
<a href={{url}}>Click me to download the file!</a>
In the NodeJs server, I have converted the MongoDB Buffer into a JavaScript ArrayBuffer through:
var buffer = Buffer.from(recordingFiles[0].blobFile);
var arrayBuffer = Uint8Array.from(buffer).buffer;
I am unsure where to proceed from here. I seen solutions using fs or res.download(), but they don't seem applicable to my situation. Thanks in advance for any help!
Hopefully this can help.
var blob = new Blob(BUFFER, {type: "audio mime type"});
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
var fileName = reportName;
link.download = fileName;
link.click();
Do you always need to preload the audio file onto the page?
If not, then I would advise you to add a separate endpoint to download the file on demand. The frontend link can send a get request to the endpoint and download the file only if the user clicked it.
Otherwise you'd always be downloading the buffer behind the scenes, even if the user didn't intend to download it. This is especially problematic on slow connections.
Frontend:
<a href={{`${baseUrl}/download/${audioId}`}}>Click me to download the file!</a>
Backend:
const stream = require('stream');
app.get('/download/:audioId', function (request, response) {
// Retrieve the tag from our URL path
const audioId = request.params.audioId;
const fileData; // TODO: Get file buffer from mongo.
const fileContents = Buffer.from(fileData, 'base64');
const readStream = new stream.PassThrough();
readStream.end(fileContents);
response.set('Content-disposition', 'attachment; filename=' + fileName);
response.set('Content-Type', '<your MIME type here>');
readStream.pipe(response);
});
A list of relevant MIME types can be found here.

Node Express Fast CSV download to client

I've set up a small node js BE app, built with express and fastCsv module on top of it. The desired outcome would be to be able to download a csv file to the client side, without storing it anywhere inside the server, since the data is generated depending on user criteria.
So far I've been able to get somewhere it it, Im using streams, since that csv file could be pretty large depending on the user selection. Im pretty sure something is missing inside the code bellow:
const fs = require('fs');
const fastCsv = require('fast-csv');
.....
(inside api request)
.....
router.get('/', async(req, res) => {
const gatheredData ...
const filename = 'sometest.csv'
res.writeHead(200, {
'Content-Type': 'text/csv',
'Content-Disposition': 'attachment; filename=' + filename
})
const csvDataStream = fastCsv.write(data, {headers: true}).pipe(res)
})
The above code 'works' in some way as it does deliver back the response, but not the actual file, but the contents of the csv file, which I can view in the preview tab as a response. To sum up, Im trying to stream in that data, into a csv and push it to download file to client, and not store it on the server. Any tips or pointers are very much appreciated.
Here's what worked for me after created a CSV file on the server using the fast-csv package. You need to specify the full, absolute directory path where the output CSV file was created:
const csv = require("fast-csv");
const csvDir = "abs/path/to/csv/dir";
const filename = "my-data.csv";
const csvOutput = `${csvDir}/${filename}`;
console.log(`csvOutput: ${csvOutput}`); // full path
/*
CREATE YOUR csvOutput FILE USING 'fast-csv' HERE
*/
res.type("text/csv");
res.header("Content-Disposition", `attachment; filename="${filename}"`);
res.header("Content-Type", "text/csv");
res.sendFile(filename, { root: csvDir });
You need to make sure to change the response content-type and headers to "text/csv", and try enclosing the filename=... part in double-quotes, like in the above example.

Extract WAV header on javascript frontend (ReactJS)

I'm trying to analyze a file I'll be uploading from react, I need to know if it can be uploaded based on several factors.
I found https://github.com/TooTallNate/node-wav
It works great on nodejs and I'm trying to use it on react. The sample creates a readable stream and pipes it to the wav reader.
var fs = require('fs');
var wav = require('wav');
var file = fs.createReadStream('track01.wav');
var reader = new wav.Reader();
// the "format" event gets emitted at the end of the WAVE header
reader.on('format', function (format) {
//Format of the file
console.log(format);
});
file.pipe(reader);
Using FilePond controller I'm able to get a base64 string of the file. But I can't figure out how to pass it to the reader
this is what I have so far on ReactJS:
var reader = new wav.Reader();
reader.on('format', function (format) {
//Format of file
console.log('format', format);
});
const buffer = new Buffer(base64String, 'base64')
const readable = new Readable()
readable._read = () => { }
readable.push(buffer)
readable.push(null)
readable.pipe(reader)
But I get Error: bad "chunk id": expected "RIFF" or "RIFX", got "u+Zj"
Since this file works on NodeJS with the same lib is obvious I'm doing something wrong.
EDIT:
this was a problem with my Base64 string, this method works if anyone needs to analyze a wav on the frontend

Get file name in express request stream

Im wondering if is posible to know what is the file name of an incomming binary request.
This is my situation I have this code that handles the file upload
router.route('/:filename')
.put(function(req,res){
var uuid = guid();
var fileExtension = req.params.filename.substring(req.params.filename.lastIndexOf("."));
if(!fs.existsSync('../files')){
fs.mkdirSync('../files')
}
var newFile = fs.createWriteStream('../files/'+uuid+fileExtension);
req.pipe(newFile);
req.on('end',function(end){
console.log("Finished")
res.send(uuid+fileExtension)
})
})
as you can see now ,I need the file name specified in the URL('/:filename'). My question is: If it is possible to take that attribute from the resquest stream, instead the url or a form key?
If you use multer middleware you can access the uploaded filename like so
var multer = require('multer')
var upload = multer()
router.route('/:filename')
.put(upload.single('fileField'),function(req,res){
var fileName = req.file.originalname
var uuid = guid();
var fileExtension = req.params.filename.substring(req.params.filename.lastIndexOf("."));
if(!fs.existsSync('../files')){
fs.mkdirSync('../files')
}
var newFile = fs.createWriteStream('../files/'+uuid+fileExtension);
req.pipe(newFile);
req.on('end',function(end){
console.log("Finished")
res.send(uuid+fileExtension)
})
})
You'll need to inspect the Content-Disposition header of the request and parse the file name information out if processing the HTTP request manually.
However, I'd recommend you look at some of the existing file upload middlewares, no point in reinventing the wheel
busboy
multer
formidable
multiparty
pez

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