ShaMan123 / canvas2pdf

Export your HTML canvas to PDF

Canvas2PDF

Usage in PDFTron

The modified files of canvas2pdf.js and pdfkit.standalone.js in this repository are used in Pdftron's CanvasToPDF API here https://github.com/PDFTron/CanvasToPDF

About

Canvas2PDF exports your HTML canvas as PDF using JavaScript. Note that this library generates actual PDF drawing calls to create a PDF with vector graphics, unlike some alternate libraries which rasterize your canvas and place it as an image in your PDF.

How it works

We create a mock 2d canvas context. Use the canvas context like you would on a normal canvas. As you call methods, we use PDFKit to generate a PDF document.

Browser Usage

//Create a new PDF canvas context.
var ctx = new canvas2pdf.PdfContext(blobStream());

//draw your canvas like you would normally
ctx.fillStyle = "yellow";
ctx.fillRect(100, 100, 100, 100);
// more canvas drawing, etc...

//convert your PDF to a Blob and save to file
ctx.stream.on("finish", function () {
  var blob = ctx.stream.toBlob("application/pdf");
  saveAs(blob, "example.pdf", true);
});
ctx.end();

Node Usage

PDFDocument = require("pdfkit");
const fs = require("fs");
const canvas2pdf = require("canvas2pdf");

const file = fs.createWriteStream("example.pdf");
//Create a new PDF canvas context.
const ctx = new canvas2pdf.PdfContext(file);

//draw your canvas like you would normally
ctx.fillStyle = "yellow";
ctx.fillRect(100, 100, 100, 100);
// more canvas drawing, etc...

ctx.stream.on("finish", function () {
  file.end();
});
ctx.end();

Dependencies

• PDFKit
• blob-stream required when using in a web browser.

Using with node.js

canvas2pdf works with node.js. Note that neither a DOM or canvas library is needed.

Interactive Browser Demo

Open Demo

Notes

• Inspired by Canvas2Svg
• Calling fill and then stroke consecutively only executes fill
• Some canvas 2d context methods are not implemented yet (e.g. setTransform and arcTo)

Status

License

MIT

Developer Dependencies

• Ghostscript and GraphicsMagick are required for running tests