Customizable PDF.js Viewer

This package makes Mozilla's PDF.js viewer available to third party applications. The viewer can be customized easily. Works best with webpack.

Please don't report issues of the PDF.js viewer bundled with this library on the PDF.js repository, as they might be caused by modifications of this library!

Also, please rebrand the viewer as requested by PDF.js, so that users don't mistake this build for Firefox's pdf viewer.

Usage (Webpack)

I recommend to host the viewer in its own iframe, otherwise style and id conflicts might occur.

First, install the npm package:

yarn add @hediet/pdfjs-viewer

Then, setup the viewer entry (viewer.ts):

import "@hediet/pdfjs-viewer/dist/assets/viewer.css";
import { loadViewer } from "@hediet/pdfjs-viewer";
loadViewer({ pdfUrl: "/sample.pdf" });

This webpack config is recommended:

import * as webpack from "webpack";
import path = require("path");
import HtmlWebpackPlugin = require("html-webpack-plugin");
import CopyWebpackPlugin = require("copy-webpack-plugin");

const r = (file: string) => path.resolve(__dirname, file);

module.exports = {
	output: { path: r("dist"), },

	// Add your own entry point and the viewer entry point
	entry: { main: r("src/index.ts"), viewer: r("src/viewer.ts") },

	plugins: [
		new CopyWebpackPlugin({ patterns: [{
			from: path.join(
				require.resolve("@hediet/pdfjs-viewer/package.json"),
				"../dist/assets"
			),
		}]}),
		// Setup an `index.html`
		new HtmlWebpackPlugin({ chunks: ["main"], }),
		// And a `viewer.html` that uses the viewer entry point.
		new HtmlWebpackPlugin({ chunks: ["viewer"], filename: "viewer.html", }),
	],
	resolve: {
		extensions: [".webpack.js", ".web.js", ".ts", ".tsx", ".js"],
	},
	devtool: "source-map",
	module: {
		rules: [
			{ test: /\.tsx?$/, loader: "ts-loader", options: { transpileOnly: true }, },
			{ test: /\.css$/, use:["style-loader", "css-loader"] },
			{ test: /\.scss$/, use: ["style-loader", "css-loader", "sass-loader"] },
			{ test: /\.(jpe?g|png|gif|eot|ttf|svg|woff|woff2|md)$/i, loader: "file-loader", },
			{ test: /\.(png|gif|cur|jpg)$/, loader: 'url-loader', }
		],
	},
} as webpack.Configuration;

Customization

You can inject your own CSS styles. You can also patch the classes of the PDF viewer - they are exposed by this package.

Customization Example: Add A Play Button

This example adds a clickable play button to each PDF slide.

The following viewer.ts enables this behavior:

import { PDFPageView, loadViewer } from "@hediet/pdfjs-viewer";

const old = PDFPageView.prototype.draw;
PDFPageView.prototype.draw = function (...args) {
	const result = old.apply(this, args);

	const div = this.div;

	const playButton = document.createElement("div");
	playButton.textContent = "hell";
	div.appendChild(playButton);
	playButton.className = "playButton";
	playButton.style.position = "absolute";
	playButton.style.top = "0";
	playButton.style.right = "0";
	playButton.style.margin = "10px";


	playButton.innerHTML = `
	<svg data-icon="play" width="30" height="30" viewBox="0 0 20 20"><desc>play</desc><path d="M16 10c0-.36-.2-.67-.49-.84l.01-.01-10-6-.01.01A.991.991 0 005 3c-.55 0-1 .45-1 1v12c0 .55.45 1 1 1 .19 0 .36-.07.51-.16l.01.01 10-6-.01-.01c.29-.17.49-.48.49-.84z" fill-rule="evenodd"></path></svg>
	`;
	playButton.onclick = () => {
		window.parent.postMessage({ event: "play-from-slide", slide: this.id }, "*");
	};
		
	return result;
}

loadViewer({ pdfUrl: "/sample.pdf" });

Updating PDF.js

This library has a dependency on pdfjs-dist, so that pdf.js does not need to be build. The version of pdfjs-dist must agree with the version of the pdfjs viewer!

Use the following commands to update the pdfjs viewer:

# Update the pdfjs branch
git fetch https://github.com/mozilla/pdf.js --no-tags master:pdfjs
git checkout pdfjs
# Split out the pdfjs viewer (which is inside the web folder) and update the pdfjs-viewer branch.
# If you are using windows, this operation is significantly faster in the WSL.
git subtree split -P web -b pdfjs-viewer
git checkout master
# Merge the changes.
git subtree merge -P src/pdfjs/web pdfjs-viewer --squash

Changes to the pdf.js Viewer

A couple of modifications were required to make the pdf.js viewer easily distributable and customizable. You can see the modifications by running

git diff master:src/pdfjs/web pdfjs-viewer

Building

Run yarn build.