html2pdf with Puppeteer

pdf.js

'use strict';

const puppeteer = require('puppeteer');
const fs = require('fs'); //Filesystem

let content = fs.readFileSync(process.argv[2], "utf-8");

const createPdf = async() => {
  let browser;
  try {
    browser = await puppeteer.launch({args: [
      '--no-sandbox',
      '--disable-setuid-sandbox'
    ]});

    const page = await browser.newPage();
    await page.setContent(content, {waitUntil: 'networkidle0'});
    await page.setViewport({
      width: 1024,
      height: 768
    })
    await page.waitFor(250);
    await page.pdf({
      path: process.argv[3],
      format: 'A4',
      margin: { top: 36, right: 36, bottom: 20, left: 36 },
      printBackground: true
    });
  } catch (err) {
      console.log(err.message);
  } finally {
    if (browser) {
      browser.close();
    }
    process.exit();
  }
};

createPdf();

Parses a .html file to a string, and then converts to PDF. Set up for optimal sizing with A4 pages. If using with Rails, create a custom pdf layout that has no margins or containers, and save the html file, you can the run it through the script as below.

Usage node pdf.js input_file.html output_file.pdf

If you're adding this script to rails and wanting to pass in a string of HTML instead of a file, place the script in the vendors/assets/javascript directory and remove line 6 that parses from a file, instead just take the process.argv[2] as a string and set the content to that.

If you're deploying to heroku, you'll need the node and puppeteer buildpacks as mentioned in this post: https://www.forsbergplustwo.com/blogs/news/pdf-generation-with-chrome-headless-in-ruby-using-puppeteer-on-heroku