ClarkBook

HTML to PDF and image using WebAssembly, powered by plutobook — a robust HTML rendering library for paged media. Does not depend on Chromium, WebKit, or Gecko.

Install

npm install clarkbook

Usage

import { createBook, PageSize, Margins } from "clarkbook";

const book = await createBook();

// Render to PDF
const pdf = book.pdf("<h1>Hello</h1>", {
  pageSize: PageSize.A4,
  margins: Margins.Normal,
});

// Render to image
const image = book.image("<h1>Hello</h1>", {
  format: "png",
  width: 1200,
  height: 800,
});

Custom fonts

import { readFile } from "node:fs/promises";

const book = await createBook({
  fonts: [
    ["Inter.ttf", await readFile("./Inter.ttf")],
  ],
});

Next.js

import path from "node:path";
import { createBook } from "clarkbook";
import { NextResponse } from "next/server";
import fs from "node:fs/promises";

const fontFile = path.join(
  process.cwd(),
  "app/fonts/GoogleSans-VariableFont_GRAD,opsz,wght.ttf",
);

const book = await createBook({
  fonts: [["GoogleSans.ttf", await fs.readFile(fontFile)]],
});

export async function GET() {
  const buffer = book.image("<h1>Hello, world</h1>", {
    format: "jpeg",
  });

  return new NextResponse(new Uint8Array(buffer), {
    status: 200,
    headers: {
      "Content-Type": "image/jpeg",
      "Content-Disposition": 'inline; filename="document.jpg"',
    },
  });
}

Resources

Pass additional assets (images, stylesheets) via resources:

const pdf = book.pdf(html, {
  resources: {
    "https://example.com/style.css": await readFile("./style.css"),
  },
  baseUrl: "https://example.com/",
});

API

createBook(options?)

Option	Type	Description
fonts	[name: string, data: Uint8Array][]	Custom font files

Returns a Book instance.

book.pdf(html, options?)

Option	Type	Default
pageSize	[number, number]	PageSize.A4
margins	[number, number, number, number]	Margins.Normal
resources	Record<string, Uint8Array>	{}
userStyle	string	""
baseUrl	string	""

Returns Uint8Array.

book.image(html, options?)

Extends pdf options with:

Option	Type	Default
format	"png" | "jpeg" | "webp"	"png"
width	number	-1
height	number	-1
quality	number	90

Returns Uint8Array.

PageSize

A3, A4, A5, B4, B5, Letter, Legal, Ledger

Margins

None, Narrow, Normal, Moderate, Wide

License

MPL-2.0

Credits

Built on plutobook by the plutoprint project.