html2pdf
html2pdf converts any webpage or element into a printable PDF entirely client-side using html2canvas and jsPDF.
Getting started
HTML
The simplest way to use html2pdf is to download dist/html2pdf.bundle.min.js
to your project folder and include it in your HTML with:
<script src="html2pdf.bundle.min.js"></script>
Note: Click here for more information about using the unbundled version dist/html2canvas.min.js
.
NPM
Install html2pdf and its dependencies using NPM with npm install --save html2pdf.js
(make sure to include .js
in the package name).
Note: You can use NPM to create your project, but html2pdf will not run in Node.js, it must be run in a browser.
Bower
Install html2pdf and its dependencies using Bower with bower install --save html2pdf.js
(make sure to include .js
in the package name).
Usage
Once installed, html2pdf is ready to use. The following command will generate a PDF of #element-to-print
and prompt the user to save the result:
var element = document.getElementById('element-to-print');
html2pdf(element);
Advanced usage
Every step of html2pdf is configurable, using its new Promise-based API. If html2pdf is called without arguments, it will return a Worker
object:
var worker = html2pdf(); // Or: var worker = new html2pdf.Worker;
This worker has methods that can be chained sequentially, as each Promise resolves, and allows insertion of your own intermediate functions between steps. A prerequisite system allows you to skip over mandatory steps (like canvas creation) without any trouble:
// This will implicitly create the canvas and PDF objects before saving.
var worker = html2pdf().from(element).save();
Workflow
The basic workflow of html2pdf tasks (enforced by the prereq system) is:
.from() -> .toContainer() -> .toCanvas() -> .toImg() -> .toPdf() -> .save()
Worker API
Method | Arguments | Description |
---|---|---|
from | src, type | Sets the source (HTML string or element) for the PDF. Optional type specifies other sources: 'string' , 'element' , 'canvas' , or 'img' . |
to | target | Converts the source to the specified target ('container' , 'canvas' , 'img' , or 'pdf' ). Each target also has its own toX method that can be called directly: toContainer() , toCanvas() , toImg() , and toPdf() . |
output | type, options, src | Routes to the appropriate outputPdf or outputImg method based on specified src ('pdf' (default) or 'img' ). |
outputPdf | type, options | Sends type and options to the jsPDF object's output method, and returns the result as a Promise (use .then to access). See the jsPDF source code for more info. |
outputImg | type, options | Returns the specified data type for the image as a Promise (use .then to access). Supported types: 'img' , 'datauristring' /'dataurlstring' , and 'datauri' /'dataurl' . |
save | filename | Saves the PDF object with the optional filename (creates user download prompt). |
set | opt | Sets the specified properties. See Options below for more details. |
get | key, cbk | Returns the property specified in key , either as a Promise (use .then to access), or by calling cbk if provided. |
then | onFulfilled, onRejected | Standard Promise method, with this re-bound to the Worker, and with added progress-tracking (see Progress below). Note that .then returns a Worker , which is a subclass of Promise. |
thenCore | onFulFilled, onRejected | Standard Promise method, with this re-bound to the Worker (no progress-tracking). Note that .thenCore returns a Worker , which is a subclass of Promise. |
thenExternal | onFulfilled, onRejected | True Promise method. Using this 'exits' the Worker chain - you will not be able to continue chaining Worker methods after .thenExternal . |
catch, catchExternal | onRejected | Standard Promise method. catchExternal exits the Worker chain - you will not be able to continue chaining Worker methods after .catchExternal . |
error | msg | Throws an error in the Worker's Promise chain. |
A few aliases are also provided for convenience:
Method | Alias |
---|---|
save | saveAs |
set | using |
output | export |
then | run |
Options
html2pdf can be configured using an optional opt
parameter:
var element = document.getElementById('element-to-print');
var opt = {
margin: 1,
filename: 'myfile.pdf',
image: { type: 'jpeg', quality: 0.98 },
html2canvas: { scale: 2 },
jsPDF: { unit: 'in', format: 'letter', orientation: 'portrait' }
};
// New Promise-based usage:
html2pdf().from(element).set(opt).save();
// Old monolithic-style usage:
html2pdf(element, opt);
The opt
parameter has the following optional fields:
Name | Type | Default | Description |
---|---|---|---|
margin | number or array | 0 | PDF margin (in jsPDF units). Can be a single number, [vMargin, hMargin] , or [top, left, bottom, right] . |
filename | string | 'file.pdf' | The default filename of the exported PDF. |
image | object | {type: 'jpeg', quality: 0.95} | The image type and quality used to generate the PDF. See the Extra Features section below. |
enableLinks | boolean | true | If enabled, PDF hyperlinks are automatically added ontop of all anchor tags. |
html2canvas | object | { } | Configuration options sent directly to html2canvas (see here for usage). |
jsPDF | object | { } | Configuration options sent directly to jsPDF (see here for usage). |
Page-breaks
You may add html2pdf
-specific page-breaks to your document by adding the CSS class html2pdf__page-break
to any element (normally an empty div
). For React elements, use className=html2pdf__page-break
. During PDF creation, these elements will be given a height calculated to fill the remainder of the PDF page that they are on. Example usage:
<div id="element-to-print">
<span>I'm on page 1!</span>
<div class="html2pdf__page-break"></div>
<span>I'm on page 2!</span>
</div>
Image type and quality
You may customize the image type and quality exported from the canvas by setting the image
option. This must be an object with the following fields:
Name | Type | Default | Description |
---|---|---|---|
type | string | 'jpeg' | The image type. HTMLCanvasElement only supports 'png', 'jpeg', and 'webp' (on Chrome). |
quality | number | 0.95 | The image quality, from 0 to 1. This setting is only used for jpeg/webp (not png). |
These options are limited to the available settings for HTMLCanvasElement.toDataURL(), which ignores quality settings for 'png' images. To enable png image compression, try using the canvas-png-compression shim, which should be an in-place solution to enable png compression via the quality
option.
Progress
The Worker object returned by html2pdf()
has a built-in progress-tracking mechanism. It will be updated to allow a progress callback that will be called with each update, however it is currently a work-in-progress.
Dependencies
html2pdf depends on the external packages html2canvas, jsPDF, and es6-promise. These dependencies are automatically loaded when using NPM or the bundled package.
If using the unbundled dist/html2pdf.min.js
(or its un-minified version), you must also include each dependency. Order is important, otherwise html2canvas will be overridden by jsPDF's own internal implementation:
<script src="es6-promise.auto.min.js"></script>
<script src="jspdf.min.js"></script>
<script src="html2canvas.min.js"></script>
<script src="html2pdf.min.js"></script>
Contributing
Issues
When submitting an issue, please provide reproducible code that highlights the issue, preferably by creating a fork of this template jsFiddle (which has html2pdf already loaded). Remember that html2pdf uses html2canvas and jsPDF as dependencies, so it's a good idea to check each of those repositories' issue trackers to see if your problem has already been addressed.
Pull requests
If you want to create a new feature or bugfix, please feel free to fork and submit a pull request! Use the develop
branch, which features the latest development, and make changes to /src/
rather than directly to /dist/
. You can test your changes by rebuilding with npm run build
.
Credits
License
Copyright (c) 2017 Erik Koopmans <http://www.erik-koopmans.com/>