johnnywang1994 / jsPDF-html2canvas

A combine usage with jsPDF & html2canvas, which translating html content to PDF file.
MIT License
75 stars 9 forks source link

Downloads Version License

jsPDF-html2canvas

A combine usage with jsPDF & html2canvas, which translating html content to PDF file. Written in Typescript.

html2PDF function will auto fit the target dom width into PDF size. So no need to worry about the overflow part. And if the content height is over 1 pdf, it'll auto seperate it into another pdf page.

Install

npm i jspdf-html2canvas
import html2PDF from 'jspdf-html2canvas';

html2PDF(node, options);

since this plugin is an umd module, you can also use by cdn with /dist/jspdf-html2canvas.min.js, just remember to include both jspdf & html2canvas cdn before this plugin.

<script src="https://unpkg.com/jspdf@latest/dist/jspdf.umd.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/html2canvas@1.4.1/dist/html2canvas.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/jspdf-html2canvas@latest/dist/jspdf-html2canvas.min.js"></script>

html2PDF([Node, NodeList], options)

convert specific DOM target to print it into PDF file.

Automatically, it'll save the file, or you can define the success callback to do with the jsPDF instance.

<!-- default a4's width is 595.28px -->
<div id="page" style="width: 595.28px;color: black;background: white;">
  <h3>PDF for Test</h3>
  <p>Here is some content for testing!!</p>
</div>

<button id="btn">Generate</button>
let btn = document.getElementById('btn');
let page = document.getElementById('page');

btn.addEventListener('click', function(){
  html2PDF(page, {
    jsPDF: {
      format: 'a4',
    },
    imageType: 'image/jpeg',
    output: './pdf/generate.pdf'
  });
});

you can easily await the method to wait for pdf generated.

async function printPdf() {
  const pdf = await html2PDF(page, {
    // ...
  });
  // do something with pdf(jsPdf instance)
}

If there's some white space on top of the outputed PDF file, it might caused by the scroll problem, just add some settings for html2canvas plugin as following. see the reference

html2PDF(page, {
// ... other settings
html2canvas: {
scrollX: 0,
scrollY: -window.scrollY,
},
});

Custom multiple page supported

There might be some situation you want to print DOM seperately, just easily give the nodeList with length in it, will adjust every nodes inside seperately into a new page in the same PDF output.

for example:

<div id="page" style="width: 595.28px;color: black;background: white;">
  <div class="page page-1">
    <h3>Test page 1</h3>
    <p>This is an page for testing 1</p>
  </div>
  <div class="page page-2">
    <h3>Test page 2</h3>
    <p>This is an page for testing 1</p>
  </div>
  <div class="page page-3">
    <h3>Test page 3</h3>
    <p>This is an page for testing 1</p>
  </div>
</div>
const pages = document.getElementsByClassName('page');

btn.addEventListener('click', function(){
  html2PDF(pages, {
    jsPDF: {
      format: 'a4',
    },
    imageType: 'image/jpeg',
    output: './pdf/generate.pdf'
  });
});

Options

- jsPDF

setting for creating jsPDF's instance, please ref to JSPDF Documentation

- html2canvas

setting for html2canvas configs, please ref to html2canvas Documentation

- watermark

setting for watermark in pdf, will add watermark into each pages of your outputed pdf file.

each data type has different usage as following:

datatype: String => image url

create image watermark in the center of each page with default image scale size 1, please use .png file for watermark.

html2PDF(page, {
  watermark: './test.png',
});

datatype: Function => custom handler

define custom handler to do things for each page of pdf file.

html2PDF(page, {
  watermark({ pdf, pageNumber, totalPageNumber }) {
    // pdf: jsPDF instance
    pdf.setTextColor('#ddd');
    pdf.text(50, pdf.internal.pageSize.height - 30, `Watermark, page: ${pageNumber}/${totalPageNumber}`);
  },
});

datatype: Object => custom handler or resize image watermark

define image watermark with change ratio, or use custom handler to do with the image position.

html2PDF(page, {
  watermark: {
    src: './test.png',
    scale: 0.5
  },
});
// or
html2PDF(page, {
  watermark: {
    src: './test.png',
    handler({ pdf, imgNode, pageNumber, totalPageNumber }) {
      const props = pdf.getImageProperties(imgNode);
      // do something...
      pdf.addImage(imgNode, 'PNG', 0, 0, 40, 40);
    },
  },
});

- imageType

define the target imageType, now only support for jpeg, png, webp

// will be used like
let pageData = canvas.toDataURL(opts.imageType, opts.imageQuality);

- imageQuality

define the image quality transfered from canvas

- margin

define the margin of each page

- autoResize

define whether to auto resize the snapshot image to fit PDF layout size

- output

define name of the output PDF file

pdf.save(opts.output);

- init

function init(pdf) {
  pdf.setFont('Myfont');
  pdf.setFontSize(10);
}

define some init for jspdf initiating before printing

- success

callback function to do after all code, default will save the file with the output name setting.

Defaults options

const defaultOptions = {
  jsPDF: {
    unit: 'pt',
    format: 'a4',
  },
  html2canvas: {
    imageTimeout: 15000,
    logging: true,
    useCORS: false,
  },
  imageType: 'image/jpeg',
  imageQuality: 1,
  margin: {
    top: 0,
    right: 0,
    bottom: 0,
    left: 0,
  },
  watermark: undefined,
  autoResize: true,
  output: 'jspdf-generate.pdf',
  init: function() {},
  success: function(pdf) {
    pdf.save(this.output);
  }
}

Recommend

if you want more custom & widing solutions, you can use this npm package

html2pdf: https://www.npmjs.com/package/html2pdf.js