Create PDF in Firebase Cloud Functions

Question

I am new to javascript and I'm trying to make a PDF file from a firebase function using pdfkit. Below is my function code.

const pdfkit = require('pdfkit');
const fs = require('fs');

exports.PDFTest = functions.https.onRequest((req, res) => {

var doc = new pdfkit();

var loremIpsum = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam in...';  

doc.y = 320;
doc.fillColor('black')
doc.text(loremIpsum, {
paragraphGap: 10,
indent: 20,
align: 'justify',
columns: 2
});  

doc.pipe( res.status(200) )

});

The function starts but then a timeout error happens. Is this the best way of going about creating a pdf file in firebase? I have some html that I want made into a pdf file.

Answer 1

I worked on this too and here below you can find a sample of cloud function that is creating a PDF file from a template HTML hosted on firebase storage. It uses Hanldebars to apply some data to the template and then upload it again on firebase storage. I used node-html-pdf here.

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const pdf = require('html-pdf');
const gcs = require('@google-cloud/storage')({
  projectId: '[YOUR PROJECT ID]',
  //key generated from here https://console.firebase.google.com/project/_/settings/serviceaccounts/adminsdk?authuser=1
  keyFilename: '[YOUR KEY]'
});
const handlebars = require('handlebars');
const path = require('path');
const os = require('os');
const fs = require('fs');
const bucket = gcs.bucket('[YOUR PROJECT ID].appspot.com');

admin.initializeApp(functions.config().firebase);

exports.helloWorld = functions.https.onRequest((request, response) => {
  // data to apply to template file
  const user = {
    "date": new Date().toISOString(),
    "firstname" : "Guillaume",
  };
  const options = {
    "format": 'A4',
    "orientation": "portrait"
  };
  const localTemplate = path.join(os.tmpdir(), 'localTemplate.html');
  const localPDFFile = path.join(os.tmpdir(), 'localPDFFile.pdf');

  bucket.file('template.html').download({ destination: localTemplate }).then(() => {
    console.log("template downloaded locally");
    const source = fs.readFileSync(localTemplate, 'utf8');
    const html = handlebars.compile(source)(user);
    console.log("template compiled with user data", html);

    pdf.create(html, options).toFile(localPDFFile, function(err, res) {
      if (err){
        console.log(err);
        return response.send("PDF creation error");
      }
      console.log("pdf created locally");

      return bucket.upload(localPDFFile, { destination: user.name + '.pdf', metadata: { contentType: 'application/pdf'}}).then(() => {
        response.send("PDF created and uploaded!");
      }).catch(error => {
        console.error(error);
        response.send("PDF created and uploaded!");
      });
  });
  });
});

Hope this will help the next one doing this :)