Node.js Decoding a Base64 Image and saving it via API - node.js

I've been trying to get a quick node.js api working, but I'm running into some issues and I was hoping someone could help.
What I'm trying to do: I'm trying to pass a base64 encoded image data URI to my node.js and have it save the file to my server. I believe that I've almost got it working, but for some reason the image is getting corrupted. When I attempt to run the script when I just hardcode the dataURI in, the saved image is perfect. However, when I use the GET request, the saved file is corrupted and I cannot open it.
Here is what I have so far:
const express = require('express');
const fs = require('fs');
const app = express();
app.listen(3000, () => { console.log
('Running on port 3000...');
});
app.get('/api/users', function(req, res) {
let base64String = req.param('datauri');
let base64Image = base64String.split(';base64,').pop();
fs.writeFile('image.png', base64Image, {encoding: 'base64'}, function(err) {
console.log('File created');
});
res.send(base64Image);
});
Any help would be greatly appreciated!

You need to url decode the base64 string to replace the special characters back to their original form. I.E. swap + back to a space
You should be able to use decodeURIComponent()
var base_64 = decodeURIComponent(base_64_string);

Related

NodeJS base64 issue

I would like to be able to decode an base64 image and save it too a file I got it working with small base64 images but if the image is larger I guess the url cant decode the whole string for example.
app.get("/api/id/:w", function(req, res) {
var data = req.params.w;
var img = Buffer.from(data, 'base64');
const fs = require("fs");
fs.writeFileSync("new-path.jpg", img);
res.status(200).end(img);
});
i didnt try anything

Creating ReadStream From Uploaded File on Node.js

I am trying to receive a file on Node.js Express framework (via express-fileupload middleware), and then POST it directly to another server via the request package without saving it on the first device's disk and then re-reading it.
const streamifier = require('streamifier');
const fileUpload = require('express-fileupload');
app.use(fileUpload());
app.post('/upload', function(req, res) {
var fileBuffer = req.files.upload.data;
var fileReadStream = streamifier.createReadStream(fileBuffer);
//Use 'request' to send fileReadStream to another API for additional processing
}
However, the receiving API does not receive any file when I run this code.
When I run this other code, however, it works fine, but fs is only able to create a ReadStream from a file on the server, so it would involve me saving the file to some temporary hard disk location first, reading it again, and then sending it to the remote API, which I think is a bit wasteful.
var fs = require('fs');
app.post('/upload', function(req, res) {
var fileReadStream = fs.createReadStream('test.txt');
//Use 'request' to send fileReadStream to another API for additional processing
}
Any idea why the 1st code block results in no file received by the external API, while the 2nd one works perfectly fine? It seems that fileReadStream would be the same in both cases.
Turns out I should have just been sending the buffer by itself without transforming it into a ReadStream. However, I did have to add the name to it, or the receiving API wouldn't recognize that I was sending a file.
const fileUpload = require('express-fileupload');
app.use(fileUpload());
app.post('/upload', function(req, res) {
var fileBuffer = req.files.upload.data;
fileBuffer.name = 'test.png';
//Use 'request' to send fileBuffer to another API for additional processing
}

res.download(NodeJS) not triggering a download on the browser

I've been struggling with this for a while and can't seem to find an answer, I'm developing a website with a budgeting option, I'm sending an object from the client to the server, and that server is using PDFKit to create a PDF version of the budget, once it's created I want to actually send back that PDF to the client and trigger a download, this is what I've done
Client-side code:
let data = {
nombre: this.state.name,
email: this.state.email,
telefono: this.state.phone,
carrito: this.props.budget.cart,
subTotal: this.props.budget.subTotal,
IVA: this.props.budget.tax,
total: this.props.budget.subTotal + this.props.budget.tax
}
axios({
method: 'post',
url: 'http://localhost:1337/api/budget',
data: data
})
.then((response) => {
console.log('This is the response', response);
window.open('/download')
})
.catch((error) => {
alert(error);
})
So that data goes to my server-side code perfectly and it looks like this
const pdf = require('pdfkit');
const fs = require('fs');
const path = require('path');
exports.makePDFBudget = (req, res) => {
let myDoc = new pdf;
myDoc.pipe(fs.createWriteStream(`PDFkit/budget.pdf`));
myDoc.font('Times-Roman')
.fontSize(12)
.text(`${req.body.name} ${req.body.phone} ${req.body.email} ${req.body.cart} ${req.body.subTotal} ${req.body.total} ${req.body.tax}`);
myDoc.end()
}
That's creating my PDF, what I want now is that once it's created and the response is sent back to the client, the client opens a new window with the URL "/download" which is set to download that PDF, but that's not happening for some reason, it opens up the new window but the download never starts and it throws absolutely no error I'm my Node console or browser console
this is how I send my file to the client
const fs = require('fs');
const path = require('path');
exports.downloadPDFBudget = (req, res) => {
res.download(__dirname + 'budget.pdf', 'budget.pdf');
}
And this is how my server index looks like
const bodyParser = require('body-parser');
const express = require('express');
const app = express();
const api = express.Router();
const { makePDFBudget } = require('./PDFkit/makePDFBudget.js');
const { downloadPDFBudget } = require('./PDFkit/downloadPDFBudget.js')
app.use(express.static(__dirname + '/../public'));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json({extended: true}));
api.route('/budget')
.post(makePDFBudget)
api.route('/download')
.get(downloadPDFBudget)
app.use('/api', api);
const port = 1337;
app.listen(port);
console.log('Listening on port ', port);
module.exports = app;
I just solved it, the port in which I was running my client obviously was different from the one I was running my server, so I had to open a window to my server's port to trigger the download, I realized this because I threw a console log on the function that was supposed to do the res.download it wasn't showing up. Thanks!
I guess the main problem here:
res.download(__dirname + 'budget.jpg', 'budget.pdf');
Make a correct file name. Your file is pdf, not jpg.
At this code res.end(Buffer.from('budget.pdf')) you sending string, not file content. But headers like you want to send a file.
The last. Your application designed like you will have only one user. Could you add userId to file names? Or use DB for storing data and generate pdf on request without storing a file to the file system.

Download a youtube video file in node js using ytdl

I want to make user able to download a youtube video using node-ytdl.
For example when client side make a GET request for certain route the video should be downloaded in response.
var ytdl = require('ytdl-core');
var express= require('express');
//Init App Instance
var app=express();
app.get('/video',function(req,res){
var ytstream=ytdl("https://www.youtube.com/watch?v=hgvuvdyzYFc");
ytstream.on('data',function(data){
res.write(data);
})
ytstream.on('end',function(data){
res.send();
})
})
Above is my nodejs code. Even though in network it seems to download the response it does not make user download as a file.I don't want to store any file on server.It would be great if someone could help me how to solve the issue.
res object is a writable stream so you can directly pipe the output of ytdl to res object like this -
ytdl("http://www.youtube.com/watch?v=xzjxhskd")
.on("response", response => {
// If you want to set size of file in header
res.setHeader("content-length", response.headers["content-length"]);
})
.pipe(res);
You have to also pass the headers. Try it:
app.get('/video', (req, res) => {
var url = "https://www.youtube.com/watch?v=hgvuvdyzYFc";
res.header("Content-Disposition", 'attachment; filename="Video.mp4');
ytdl(url, {format: 'mp4'}).pipe(res);
});
If someone is still getting an error just update the package to latest version by running:
npm i ytdl-core#latest
Ok, so make a string var, then add data to it on the data event. On end, send everything. Here is an example:
const ytdl = require("ytdl-core"),
app = require("express")();
app.get("/video", (req, res) => {
let data = "", vid = ytdl("https://www.youtube.com/watch?v=hgvuvdyzYFc");
vid.on("data", d => data += d);
vid.on("end", () => res.send(data));
res.header("Content-Disposition", 'attachment; filename="Video.mp4');
});

something about request(url).pipe()

when I use request(url).pip(fs.createWriteStream("1.jpg")), url include some special codes just as "#" and "×", then the NODE.js cannot create the jpg picture, and if I create the http file service, use the url without the special code, I can get the jpg picture correctly. can somebody tell me how to handle these special codes in url?
thank you very much!
You should provide the code but I've tried this code for you.
const fs = require('fs')
const http = require('http')
const request = require('request')
let url = 'https://upload.wikimedia.org/wikipedia/en/8/8a/Text_placeholder_image.jpg' // some jpg
request(url).pipe(fs.createWriteStream('1.jpg'))
http.createServer((req, res) => {
fs.readFile('1.jpg', (error, content) => {
if (error) {
// handle error
return
}
res.writeHead(200, 'image/jpeg')
res.end(content, 'utf-8')
})
}).listen(3000)
Then, localhost:3000 worked well.
Used node v6.10.2 and request v2.81.0.

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