const PDF = require("pdfkit");
const fs = require("fs");
const express = require("express");
const app = express();
app.get("/", (req, res) => {
try {
const doc = new PDF({ size: "A4" });
doc.image("/home/rahul/Desktop/projects/test/test/vlogo.png", 10, 0, {
width: 100,
height: 100,
align: "left",
});
doc.pipe(
fs.createWriteStream("/home/rahul/Desktop/projects/test/test/doc.pdf")
);
doc.end();
res.sendFile("/home/rahul/Desktop/projects/test/test/doc.pdf");
} catch (error) {
console.log(error);
res.status(500).sendFile("Rahul");
}
});
The above code is not sending any response to the browser.
When I am loading the API in the browser, then I am getting this.
But, when I remove the doc.pipe code, then it's working fine. It's sending PDF.
You can try by commenting
// doc.pipe(
// fs.createWriteStream("/home/rahul/Desktop/projects/test/test/doc.pdf")
// );
When calling doc.end() the pdf will take some time to be written on the disk. So you are basically sending a "half written" pdf file which results in an invalid file.
So wait for the created WriteStream to finish first:
const PDF = require("pdfkit");
const fs = require("fs");
const express = require("express");
const app = express();
app.get("/", (req, res) => {
try {
const doc = new PDF({ size: "A4" });
doc.image("/home/rahul/Desktop/projects/test/test/vlogo.png", 10, 0, {
width: 100,
height: 100,
align: "left",
});
const stream = fs.createWriteStream("/home/rahul/Desktop/projects/test/test/doc.pdf")
stream.on('finish', () => {
// now, the file is fully written to disk. Let's send it back!.
res.sendFile("/home/rahul/Desktop/projects/test/test/doc.pdf");
})
stream.on('error', err => {
console.error(err)
res.status(500).send("Failed to send pdf.")
})
doc.pipe(stream);
// start writing to file!.
doc.end();
} catch (error) {
console.log(error);
res.status(500).send("Server error occured.");
}
});
Related
I am trying to use sharp in my MERN application, I sent a request from my frontend and it is undefined in my sharp middleware but if I get rid of the sharp middleware the req is defined later on. If I log the request in createCountry, the body is defined, if I log it in convertToWebP, it is not.
the route is the one that says "/new" below:
const express = require("express");
const router = express.Router();
const { storage } = require("../imageupload/cloudinary.js");
const multer = require("multer");
const {
getCountry,
createCountry,
getCountries,
updateCountry,
deleteCountry,
getAllCountries,
} = require("../controllers/country.js");
const {convertToWebP} = require('../middlewares/toWebP')
const { isLoggedIn, authorizeCountry, validateCountry } = require("../middlewares/auth");
const catchAsync = require("../utils/catchAsync");
const ExpressError = require("../utils/ExpressError");
const upload = multer({ storage: storage });
router.get("/", getCountries);
router.get('/getAll', getAllCountries);
router.post("/new", isLoggedIn, converToWebP, upload.array("images"), createCountry);
router.get("/:countryId", getCountry);
router.patch("/:countryId", validateCountry, authorizeCountry, upload.array("images", 8), updateCountry);
router.delete("/:countryId", authorizeCountry, deleteCountry);
module.exports = router;
the code for create country is here:
exports.createCountry = async (req, res) => {
const { name, description, tags, location, cjLink } = req.body;
const creator = req.user._id;
const images = req.files.map((file) => {
return { image: file.path, publicId: file.filename };
});
try {
const geoData = await geocoder
.forwardGeocode({
query: req.body.location,
limit: 1,
})
.send();
const geometry = geoData.body.features[0].geometry;
const country = new Country({
name,
description,
tags,
creator,
location, //: //geometry
geometry,
url: '',
cjLink: cjLink,
});
const overall = new Overall({
name,
description,
tags,
creator,
location, //: //geometry
geometry,
url: '',
cjLink: cjLink,
});
country.images.push(...images);
country.headerImage.push(...images);
const data = await country.save();
overall.url = `/country/${data._id}`
data.url = `/country/${data._id}`
overall.save();
data.save();
return res.status(201).json(data);
} catch (error) {
return console.log("error during create country", error);
}
};
And lastly the code for the convertToWebP is here:
const sharp = require("sharp");
const { cloudinary } = require("../imageupload/cloudinary");
exports.convertToWebP = async (req, res, next) => {
try {
req.files = await Promise.all(req.files.map(async (file) => {
const buffer = await sharp(file.buffer)
.toFormat('webp')
.toBuffer();
return { ...file, buffer, originalname: `${file.originalname}.webp` };
}));
next();
} catch (error) {
res.status(500).json({ message: error.message });
}
};
Any help is appreciated! I tried console.log as described above, I tried to change the order of the middleware and that does not work either, and I tried logging the req.body directly from the route and it came up as an empty object
You cannot acces req.files before you use multer middleware
You have to reorder
router.post("/new", isLoggedIn, upload.array("images"), converToWebP, createCountry);
I'm trying to build a certificate generation module using nodeJS.
The api to create certificate is as follows
// Create certificate
const express = require('express');
const router = express.Router();
const { createCanvas } = require('canvas')
const fs = require("fs");
const { decodeBase64Image } = require('../helper/certificatehelper');
router.post('/imageadd', async (req, res, next) => {
try {
const { name } = req.body;
const width = 1920
const height = 1080
const canvas = createCanvas(width, height)
const context = canvas.getContext('2d')
context.fillStyle = "white";
context.fillRect(0, 0, width, height)
context.fillStyle = '#000'
context.font = "72px Arial";
context.textAlign = "center";
context.fillText(name, 900, 500);
const dataurl = canvas.toDataURL();
const decodedImg = decodeBase64Image(dataurl);
const imageBuffer = decodedImg.data;
fs.writeFileSync(`./src/images/image1.png`, imageBuffer);
fs.readFile('./src/images/image1.png', function(err, data) {
if (err) throw err; // Fail if the file can't be read.
res.writeHead(200, {'Content-Type': 'image/jpeg'});
res.end(data); // Send the file data to the browser.
});
res.json({ data: respArray, success: true, msg: 'Certificate generated' });
} catch (error) {
res.json({ success: false, msg: error.message });
}
})
module.exports = router;
The problem I'm facing is, If multiple request are send in parallel how do I generate one certificate at a time (synchronized).
Other requests need to wait till the certificate is generated for previous request.
The certificates should be generated in a separate process from the main app process.
How do I solve the above given problem.
I am working with express node.js, and I am trying to save datas from post request in a json file. but for some reason when I restart the server, my data from post request was supposed to save in roomDB.json file doesnt remain instead it resets to initial empty array...
Could anyone please advice? thank you very much.
here is my code
//saving function
const fs = require("fs");
exports.save =(data, PATH) =>{
return new Promise((resolve, reject) => {
fs.writeFile(PATH, JSON.stringify(data), function(err) {
if (err) {
reject(err);
} else {
resolve();
}
});
});
}
// code in router file to make requests
const express = require("express");
const router = express.Router();
const fs = require("fs");
const rooms = ("./roomDB.json");
const { addRoom} = require("./rooms");
router.get("/", (req, res)=>{
fs.readFile("roomDB.json", (err, data)=>{
if(err) return res.status(400);
res.send(roomDB_PATH)
})
});
router.get("/:id", (req, res)=>{
res.send("connect to a room");
});
router.post("/", (req, res)=>{
let roomName = req.body;
if(!roomName.name){
res.status(404);
res.end();
return;
}
let room =addRoom(roomName.name);
res.status(201).send(room)
})
module.exports = router;
*/
const uuid = require("uuid");
let roomdatas;
const {save} = require("./save");
const roomDB_PATH = "roomDB.json";
try {
roomdatas = JSON.parse(fs.readFileSync(roomDB_PATH));
} catch (e) {
roomdatas = []
save(roomdatas, roomDB_PATH);
}
const addRoom = (roomName) => {
roomName = roomName.trim().toLowerCase();
const existingRoom = roomdatas.find((room) => room.name === roomName);
if (existingRoom) {
return { error: 'chatroom has existed' };
}
let room = {
name: roomName,
id: uuid.v4(),
messages: [],
users: [],
created: +new Date()
};
roomdatas.push(room);
save(roomdatas, roomDB_PATH);
return { room };
};
module.exports ={addRoom};
I'm assuming that you are encountering an error with the JSON.parse(fs.readFileSync(roomDB_PATH)); call. This code runs every time your server is started (when you import the file into your router file), and if it encounters an error it is resetting the file to an empty array. Try logging the error to see what is causing it. You're currently completely suppressing the error with no way to tell why it is failing.
I want to stream a file upload request in multipart/form-data to another server and change some fields name at the same time.
I don't want to store temporarily a file on disk and don't want to store the file completely in memory either.
I tried to use multer, busboy and multiparty. I think I got closer by using custom Transform streams but it is not working yet.
const express = require('express');
const request = require('request');
const { Transform } = require('stream');
const router = express.Router();
class TransformStream extends Transform {
_transform(chunk, encoding, callback) {
// here I tried to manipulate the chunk
this.push(chunk);
callback();
}
_flush(callback) {
callback();
}
}
router.post('/', function pipeFile(req, res) {
const transformStream = new TransformStream();
req.pipe(transformStream).pipe(request.post('http://somewhere.com'));
res.sendStatus(204);
});
I tried to manipulate chunks in _transform without success (EPIPE). It sounds quit hacky, are they any better solutions ?
Here is a solution using replacestream along with content-disposition.
const replaceStream = require('replacestream');
const contentDisposition = require('content-disposition');
router.post('/', function pipeFile(req, res) {
let changeFields = replaceStream(/Content-Disposition:\s+(.+)/g, (match, p1) => {
// Parse header
let {type, parameters} = contentDisposition.parse(p1);
// Change the desired field
parameters.name = "foo";
// Prepare replacement
let ret = `Content-Disposition: ${type}`;
for(let key in parameters) {
ret += `; ${key}="${parameters[key]}"`;
}
return ret;
})
req.pipe(changeFields)
.pipe(request.post('http://somewhere.com'))
.on('end', () => {
res.sendStatus(204);
});
});
This worked for a single file multipart upload using express, multiparty, form-data, pump and got.
const stream = require('stream');
const express = require('express');
const multiparty = require("multiparty");
const got = require("got");
const FormData = require('form-data');
const pump = require('pump');
const app = express();
app.post('/upload', (req, res) => {
const url = "<<multipart image upload endpoint>>";
var form = new multiparty.Form();
form.on("part", function(formPart) {
var contentType = formPart.headers['content-type'];
var formData = new FormData();
formData.append("file", formPart, {
filename: formPart.filename,
contentType: contentType,
knownLength: formPart.byteCount
});
const resultStream = new stream.PassThrough();
try {
// Pipe the formdata to the image upload endpoint stream and the result to the result stream
pump(formData, got.stream.post(url, {headers: formData.getHeaders(), https:{rejectUnauthorized: false}}), resultStream, (err) =>{
if(err) {
res.send(error);
}
else {
// Pipe the result of the image upload endpoint to the response when there are no errors.
resultStream.pipe(res);
}
resultStream.destroy();
});
}
catch(err) {
resultStream.destroy();
console.log(err);
}
});
form.on("error", function(error){
console.log(error);
})
form.parse(req);
});
I am working on a small project that works with generating pdf's in node and express, l am using the pdfkit npm module but to generate a pdf. l am also using the qr-image npm module to generate the QR code image but l am struggling to attach the generated the QR code to the pdf. This is the code that l am using to generate the QR code:
var file = "./"+certificationnumber+".png";
var qr_svg = qr.image(file, { type: 'png' });
qr_svg.pipe(require('fs').createWriteStream(file));
And this is how l am trying attache it to the pdf using pdfkit npm module:
doc.image(qr_svg.pipe(require('fs').createWriteStream(file)))
since every pdf has a unique QR code.
Thanks in advance
I exactly have the same problem where get the PDF in 64 bit encoded form and i have to attach qr image to it.
Below is the code snippet.
PDFDocument = require('pdfkit');
const base64 = require('base64-stream');
const doc = new PDFDocument();
doc.image('test.jpeg', {
fit: [250, 300],
align: 'center',
valign: 'center'
});
const finalString = pdf.response;
// contains the base64 string
//logic to append the qr image.
const stream = doc.pipe(base64.encode());
stream.on('data', chunk => finalString += chunk);
stream.on('end', () => {
// the stream is at its end, so push the resulting base64 string to the response
const backToPDF = new Buffer(finalString, 'base64');
read.writeFileSync('./Report.pdf', backToPDF);
});
doc.end();
Here is the solution I have come up with. Using pdf-lib, express and qrcode
const fs = require("fs");
const path = require("path");
const express = require("express");
const http = require("http");
const cors = require("cors");
const multer = require("multer");
const app = express();
const server = http.createServer(app);
const { PDFDocument } = require("pdf-lib");
const QRCode = require("qrcode");
const Joi = require("joi");
const { readFile, writeFile, unlink } = require("fs/promises");
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
const dir = "public";
const subDirectory = "public/uploads";
if (!fs.existsSync(dir)) {
fs.mkdirSync(dir);
fs.mkdirSync(subDirectory);
}
const generateQRCodeImage = async function (filePath, text, color) {
return new Promise((resolve, reject) => {
QRCode.toFile(
filePath,
text,
{
color,
},
function (err) {
if (err) return reject(err);
resolve();
}
);
});
};
const run = async ({
width,
height,
x,
y,
pathToImage,
pathToPDF,
pathToOutputPDF,
qrCodeText,
qrDarkColor = "#000",
qrLightColor = "#0000",
}) => {
await generateQRCodeImage(pathToImage, qrCodeText, {
dark: qrDarkColor,
light: qrLightColor,
});
const pdfDoc = await PDFDocument.load(await readFile(pathToPDF));
const img = await pdfDoc.embedPng(await readFile(pathToImage));
Array.from({ length: pdfDoc.getPageCount() }).forEach((_, index) => {
let imagePage = pdfDoc.getPage(index);
imagePage.drawImage(img, {
x,
y,
width,
height,
});
});
const pdfBytes = await pdfDoc.save();
await writeFile(pathToOutputPDF, pdfBytes);
};
const pdfFileFilter = function (req, file, callback) {
const ext = path.extname(file.originalname);
if (ext !== ".pdf") {
return callback("This extension is not supported");
}
callback(null, true);
};
const storage = multer.diskStorage({
destination: function (req, file, cb) {
cb(null, "public/uploads");
},
filename: function (req, file, cb) {
cb(
null,
file.fieldname + "-" + Date.now() + path.extname(file.originalname)
);
},
});
const filesToProcess = multer({ storage: storage, fileFilter: pdfFileFilter });
const schema = Joi.object({
width: Joi.string().regex(/^\d+$/).required(),
height: Joi.string().regex(/^\d+$/).required(),
x: Joi.string().regex(/^\d+$/).required(),
y: Joi.string().regex(/^\d+$/).required(),
qrCodeData: Joi.string().required(),
qrDarkColor: Joi.string(),
qrLightColor: Joi.string(),
});
app.post("/addQrToPdf", filesToProcess.array("file", 1), async (req, res) => {
const pathToImage = "public/uploads/" + Date.now() + "temp-qr.png";
const pathToOutputPDF = "public/uploads/" + Date.now() + "-output.pdf";
if (req.files) {
const [file] = req.files;
if (!file) {
res.send("No file detected on input");
}
const pathToPDF = file.path;
try {
const { width, height, x, y, qrCodeData, qrDarkColor, qrLightColor } =
await schema.validateAsync(req.body);
await run({
width: +width,
height: +height,
x: +x,
y: +y,
qrDarkColor,
qrLightColor,
qrCodeText: qrCodeData,
pathToImage,
pathToOutputPDF,
pathToPDF,
});
const pdfFile = await readFile(pathToOutputPDF);
res.contentType("application/pdf");
res.send(pdfFile);
await unlink(pathToImage);
await unlink(pathToPDF);
await unlink(pathToOutputPDF);
} catch (error) {
try {
await unlink(pathToPDF);
await unlink(pathToImage);
} catch (err) {
console.warn(err);
}
res.send(error);
}
}
});
server.listen(4000, () => console.log("listening on port *:4000"));
I had the same problem.
It looks like it is an async issue.
If you treat the generation of the QR code like a promise and then run the create pdf code, it works.
My code is below (using promise). It should also work using async await
const createPDF = (ticketID) => {
const doc = new pdf
doc.pipe(fs.createWriteStream(`${ticketID}.pdf`))
doc.text('Your Tickets').fontSize(25)
doc.image(`./qrCodes/${ticketID}.png`, {
fit: [250, 300],
align: 'center',
valign: 'center'
});
doc.end()
}
const createQRCode = (ticketID) => {
QR.toFile(`./qrCodes/${ticketID}.png`, String(ticket), {width: 250}).then(qr => {
createPDF(ticketID)
})
}
I use a version without writing to the disk, using the svg path output, extract the path from the qrcode data and render it into the pdf
let s = await toString('hallo2', {
type: 'svg'
})
// extract the 2nd path element
let path = Array.from(s.matchAll(/d="(.*?)"/gm))[1][1]
let doc = new PDFDocument({ size: 'A4' });
doc.scale(8)
.path(data)
.stroke()
doc.pipe(fs.createWriteStream('out2.pdf', {}));
doc.end()