Link Annotation inside pdfkit and node-signpdf

Software Used:

• Nodejs
• pdfkit 1.23
• node-signpdf 1.2.3
• node-forge 0.7.6

Wanted:

I want to create a pdf that has a link inside it and sign that pdf with password

Question:

How to do it … ?

Answer:

We will create 2 files:

• helpers.js
• index.js used

helpers.js

Create a file named it helpers.js and insert this code below:

const PDFDocument = require('pdfkit');

module.exports = {
	
 createPdf(params) {
    return new Promise((resolve) => {
        const pdf = new PDFDocument({
          autoFirstPage: true,
          size: 'A4',
          layout: 'portrait',
          bufferPages: true,
      });
	  
	
pdf.info.CreationDate = '';
  
pdf.text(params.title,75,90)
	
pdf.text('Copyright © 2020',{continued:true}).fillColor('blue')
pdf.text('Fahmi Basya',{link: 'https://a2fahmi.com'})
	
const pdfChunks = [];
pdf.on('data', (data) => {
      pdfChunks.push(data);
});
 
pdf.on('end', () => {
      resolve(Buffer.concat(pdfChunks));
});
  
	
      pdf.end();
    })
  }  
}

Explain:

• pdf.text(params.title,75,90) used for create text in x-coordinate=75 and y-coordinate = 90
• pdf.text(‘Fahmi Basya’,{link: ‘http://a2fahmi.com’}) used for create a ‘Fahmi Basya’ text and linked to ‘http://a2fahmi.com’

index.js

const {SignPdf} = require('node-signpdf');
const fs = require('fs');
const {plainAddPlaceholder} = require ('node-signpdf/dist/helpers');
const {createPdf} = require('./helpers');
const signPdf = new SignPdf();

async function signPdfWithPassphrase(passphrase) {
	
const p12Buffer = fs.readFileSync(`${__dirname}/resources/withpass.p12`);
	
let data={title:'Learning Creating PDF with nodejs and pdfkit'}
let pdfBuffer = await createPdf(data);
	
	pdfBuffer = plainAddPlaceholder({
            pdfBuffer,
            reason: 'I have reviewed it.',
            signatureLength: 1612,
        });

    const signedPdfBuffer = signPdf.sign(
        pdfBuffer,
        p12Buffer,
        {passphrase}
    );    
	
const outputPath = `${__dirname}/output/pdfkit-sample-signed-with-passphrase.pdf`;
fs.writeFileSync(outputPath, signedPdfBuffer);
console.log('Pdf signed and saved to:', outputPath);
	
}

Running the Code

Just call this code:

signPdfWithPassphrase('your password')

Thanks for reading