Generating a PDF file from React Components

I have been building a polling application. People are able to create their polls and get data regarding the question(s) they ask. I would like to add the functionality to let the users download the results in the form of a PDF.

For example I have two components which are responsible for grabbing the question and data.

<QuestionBox />
<ViewCharts />

I'm attempting to output both components into a PDF file. The user can then download this PFD file. I have found a few packages that permit the rendering of a PDF inside a component. However I failed to find one that can generate PDF from an input stream consisting of a virtual DOM. If I want to achieve this from scratch what approach should I follow ?

Rendering react as pdf is generally a pain, but there is a way around it using canvas.

The idea is to convert : HTML -> Canvas -> PNG (or JPEG) -> PDF

To achieve the above, you'll need :

1. html2canvas &
2. jsPDF

import React, {Component, PropTypes} from 'react';

// download html2canvas and jsPDF and save the files in app/ext, or somewhere else
// the built versions are directly consumable
// import {html2canvas, jsPDF} from 'app/ext';


export default class Export extends Component {
  constructor(props) {
    super(props);
  }

  printDocument() {
    const input = document.getElementById('divToPrint');
    html2canvas(input)
      .then((canvas) => {
        const imgData = canvas.toDataURL('image/png');
        const pdf = new jsPDF();
        pdf.addImage(imgData, 'JPEG', 0, 0);
        // pdf.output('dataurlnewwindow');
        pdf.save("download.pdf");
      })
    ;
  }

  render() {
    return (<div>
      <div className="mb5">
        <button onClick={this.printDocument}>Print</button>
      </div>
      <div id="divToPrint" className="mt4" {...css({
        backgroundColor: '#f5f5f5',
        width: '210mm',
        minHeight: '297mm',
        marginLeft: 'auto',
        marginRight: 'auto'
      })}>
        <div>Note: Here the dimensions of div are same as A4</div> 
        <div>You Can add any component here</div>
      </div>
    </div>);
  }
}

The snippet will not work here because the required files are not imported.

An alternate approach is being used in this answer, where the middle steps are dropped and you can simply convert from HTML to PDF. There is an option to do this in the jsPDF documentation as well, but from personal observation, I feel that better accuracy is achieved when dom is converted into png first.

Update 0: September 14, 2018

The text on the pdfs created by this approach will not be selectable. If that's a requirement, you might find this article helpful.

you can user canvans with jsPDF

import jsPDF from 'jspdf';
import html2canvas from 'html2canvas';

 _exportPdf = () => {

     html2canvas(document.querySelector("#capture")).then(canvas => {
        document.body.appendChild(canvas);  // if you want see your screenshot in body.
        const imgData = canvas.toDataURL('image/png');
        const pdf = new jsPDF();
        pdf.addImage(imgData, 'PNG', 0, 0);
        pdf.save("download.pdf"); 
    });

 }

and you div with id capture is:

example

<div id="capture">
  <p>Hello in my life</p>
  <span>How can hellp you</span>
</div>

React-PDF is a great resource for this.

It is a bit time consuming converting your markup and CSS to React-PDF's format, but it is easy to understand. Exporting a PDF and from it is fairly straightforward.

To allow a user to download a PDF generated by react-PDF, use their on the fly rendering, which provides a customizable download link. When clicked, the site renders and downloads the PDF for the user.

Here's their REPL which will familiarize you with the markup and styling required. They have a download link for the PDF too, but they don't show the code for that here.

Only few steps. We can download or generate PDF from our HTML page or we can generate PDF of specific div from a HTML page.

Steps : HTML -> Image (PNG or JPEG) -> PDF

Please Follow the below steps,

Step 1 :-

npm install --save html-to-image
npm install jspdf --save

Step 2 :-

/* ES6 */
import * as htmlToImage from 'html-to-image';
import { toPng, toJpeg, toBlob, toPixelData, toSvg } from 'html-to-image';
 
/* ES5 */
var htmlToImage = require('html-to-image');

-------------------------
import { jsPDF } from "jspdf";

Step 3 :-

   ******  With out PDF properties given below  ******

 htmlToImage.toPng(document.getElementById('myPage'), { quality: 0.95 })
        .then(function (dataUrl) {
          var link = document.createElement('a');
          link.download = 'my-image-name.jpeg';
          const pdf = new jsPDF();          
          pdf.addImage(dataUrl, 'PNG', 0, 0);
          pdf.save("download.pdf"); 
        });


    ******  With PDF properties given below ******

    htmlToImage.toPng(document.getElementById('myPage'), { quality: 0.95 })
        .then(function (dataUrl) {
          var link = document.createElement('a');
          link.download = 'my-image-name.jpeg';
          const pdf = new jsPDF();
          const imgProps= pdf.getImageProperties(dataUrl);
          const pdfWidth = pdf.internal.pageSize.getWidth();
          const pdfHeight = (imgProps.height * pdfWidth) / imgProps.width;
          pdf.addImage(dataUrl, 'PNG', 0, 0,pdfWidth, pdfHeight);
          pdf.save("download.pdf"); 
        });

I think this is helpful. Please try

You can use ReactDOMServer to render your component to HTML and then use this on jsPDF.

First do the imports:

import React from "react";
import ReactDOMServer from "react-dom/server";
import jsPDF from 'jspdf';

then:

var doc = new jsPDF();
doc.fromHTML(ReactDOMServer.renderToStaticMarkup(this.render()));
doc.save("myDocument.pdf");

Prefer to use: > renderToStaticMarkup

instead of: > renderToString

As the former include HTML code that react relies on.

my opinion : 

import { useRef } from "react";
import { jsPDF } from "jspdf";
import html2canvas from "html2canvas";

import "./styles.css";

const App = () => {
  const inputRef = useRef(null);
  const printDocument = () => {
    html2canvas(inputRef.current).then((canvas) => {
      const imgData = canvas.toDataURL("image/png");
      const pdf = new jsPDF();
      pdf.addImage(imgData, "JPEG", 0, 0);
      pdf.save("download.pdf");
    });
  };
  return (
    <>
      <div className="App">
        <div className="mb5">
          <button onClick={printDocument}>Print</button>
        </div>
        <div id="divToPrint" ref={inputRef}>
          <div>Note: Here the dimensions of div are same as A4</div>
          <div>You Can add any component here</div>
        </div>
      </div>
    </>
  );
};
export default App;

link demo:

https://codesandbox.io/s/frosty-sea-44b4q?file=/src/App.js:0-907

This may or may not be a sub-optimal way of doing things, but the simplest solution to the multi-page problem I found was to ensure all rendering is done before calling the jsPDFObj.save method.

As for rendering hidden articles, this is solved with a similar fix to css image text replacement, I position absolutely the element to be rendered -9999px off the page left, this doesn't affect layout and allows for the elem to be visible to html2pdf, especially when using tabs, accordions and other UI components that depend on {display: none}.

This method wraps the prerequisites in a promise and calls pdf.save() in the finally() method. I cannot be sure that this is foolproof, or an anti-pattern, but it would seem that it works in most cases I have thrown at it.

// Get List of paged elements.
let elems = document.querySelectorAll('.elemClass');
let pdf = new jsPDF("portrait", "mm", "a4");

// Fix Graphics Output by scaling PDF and html2canvas output to 2
pdf.scaleFactor = 2;

// Create a new promise with the loop body
let addPages = new Promise((resolve,reject)=>{
  elems.forEach((elem, idx) => {
    // Scaling fix set scale to 2
    html2canvas(elem, {scale: "2"})
      .then(canvas =>{
        if(idx < elems.length - 1){
          pdf.addImage(canvas.toDataURL("image/png"), 0, 0, 210, 297);
          pdf.addPage();
        } else {
          pdf.addImage(canvas.toDataURL("image/png"), 0, 0, 210, 297);
          console.log("Reached last page, completing");
        }
  })
  
  setTimeout(resolve, 100, "Timeout adding page #" + idx);
})

addPages.finally(()=>{
   console.log("Saving PDF");
   pdf.save();
});

npm install jspdf --save

//code on react

import jsPDF from 'jspdf';


var doc = new jsPDF()


 doc.fromHTML("<div>JOmin</div>", 1, 1)


onclick //

 doc.save("name.pdf")

I used jsPDF and html-to-image.

You can check out the code on the below git repo.

Link

> If you like, you can drop a star there✌️

You can also try "React on the fly pdf" which will generate pdf from HTML. This plugin uses html2canvas and jspdf under the hood to generate the pdf document. This plugin supports multiple pages, header and footer. I like to warn you that it won't generate "real" pdf. Meaning real pdf should be vector. I can't think of any of Javascript plugin which can generate real pdf. You need to use some other tools to do that.

You can use ReactPDF

Lets you convert a div into PDF with ease. You will need to match your existing markup to use ReactPDF markup, but it is worth it.