starlight-to-pdf

• Description
• ⌨️ Getting started
• 👨‍💻 CLI Flags Reference
  • Usage example
  • Special CSS classes
  • PDF header and footer
  • Demo
• 🤖 GitHub Actions
  • Deploying with Netlify
  • Generating PDF locally
• 📨 Contacts
• 🪪 License

📖 Description

A command-line tool for converting documentation websites built with 🌟Starlight into PDF files.

Have questions or suggestions? Feel free to open an issue. Contributions are always welcome!

If you are interested in the development process, check out the Transforming Starlight into PDF: experience and insights article.

⌨️ Getting started

Convert your Starlight documentation into a PDF file with a single command:

npx starlight-to-pdf https://starlight.astro.build

Note: Ensure you have Node.js (v18 or higher) and Chrome browser installed on your machine.

URL is the only positional and required argument. Alternatively, you can use the --url (or -u) flag to specify it.

👨‍💻 CLI Flags Reference

Flag	Short	Type	Description
--url	-u	string	The URL of the Starlight powered documentation website to convert to PDF. The only positional argument can be used instead of this flag. See ⌨️ Getting started for details.
--browser-executable		string	Specifies a path to a browser executable to use instead of the default one (e.g. --browser-executable /usr/bin/chromium-browser).
--contents-name		string	Customizes the generated table of contents name in the PDF. Default: "Contents"
--contents-links		'internal' | 'external'	Specifies the type of links in the generated table of contents. Use 'internal' for links that navigate within the PDF file or 'external' for links that point to the documentation website. Default: 'external'
--css-page-size		boolean	Allows setting the PDF page size using CSS @page. If the predefined sizes in the --format option don't meet your needs, enable this option and specify the desired page size in custom CSS provided via the --styles flag (e.g., @page { size: 8.5in 14in; }). Note: if you define a page size in CSS without enabling this option, the size from the --format option will be used instead, and the content will be scaled to fit the dimensions specified in @page.
--exclude	-e	string	A string containing links separated by space that shouldn't be added to the resulting PDF file (e.g. --exclude '/docs/contacts /docs/demo'). You may also provide multiple values: -e /docs/contacts -e /docs/demo.
--filename	-f	string	The output filename for the PDF. Default is the hostname of the provided URL.
--following-html		string	Path to an HTML file which content will be inserted an the end of the PDF file. Its behavior is similar to the --preceding-html option.
--footer		string	Path to an HTML file for the PDF print footer. For more details, check PDF header and footer section and Puppeteer's PDFOptions.
--format		string	The paper format (e.g., A4, Letter) for the PDF file. Refer to Puppeteer's paper formats for more details
--header		string	Path to an HTML file that will be used as a print header for the generated PDF. For more details, check PDF header and footer section and Puppeteer's PDFOptions.
--help	-h	boolean	Displays the help message and exits.
--last	-l	string	Sets the last link to parse (e.g. --last /docs/demo). Further parsing stops once this link is reached and parsed.
--margins		string	Sets margins for the PDF file. Provide a string with 4 values separated by space, reflecting the top, right, bottom and left margins respectively. Default value is '1cm 1cm 1cm 1.5cm'.
--no-contents		boolean	Disables generation of the table of contents in the PDF.
--no-starlight-print-css		boolean	Disables the default @media print CSS styles applied by Starlight. Enabling this flag retains the website's original colors when printing.
--paddings		string	Sets padding for the PDF content. Provide a string with 4 values separated by space, reflecting the top, right, bottom and left paddings respectively. Paddings are disabled by default.
--path	-p	string	Sets the directory path for the output PDF. Default is the current working directory.
--pdf-outline		boolean	Enables a side outline in the PDF file. It's an outline property in Puppeteer's PDFOptions.
--preceding-html		string	Path to an HTML file which content will be inserted an the beginning of the PDF file. This option may be useful for adding a cover page. See cover.html and the resulting PDF for examples.
--print-bg		boolean	Enables printing of background graphics. It's a printBackground property in Puppeteer's PDFOptions.
--styles		string	Path to a CSS file for custom PDF styles. The styles are injected into the <style> tag inside the <body> element. Also check the list of special CSS classes used by the tool.
--timeout		string	Timeout for both the page actions and protocolTimeout in milliseconds. You may need to increase this value for parsing large websites. The default value is 180_000 (2 minutes).
--version	-v	boolean	Displays the tool version and exits.

Usage example

npx starlight-to-pdf spectrum.snipshot.dev -p ./output --filename spectrum-docs --contents-name "Table of contents" --margins '0 0 0 0' --paddings '2cm 1cm 2cm 1.5cm' --exclude '/demo /contacts' --header ./readme_assets/header-template.html --footer ./readme_assets/footer-template.html --print-bg --pdf-outline

Resulting PDF file: spectrum-docs.pdf

Special CSS classes

• .s2pdf-container - The wrapper around all the website parsed content (excluding the table of contents).
• .s2pdf-contents - The <ul> element containing the generated table of contents.
• .s2pdf-heading - The element that contains <h1> headings of each page.
• .s2pdf-pagebreak - Each page text content with a defined CSS break-after: page property.

PDF header and footer

You can provide an HTML template for the print header and footer of the generated PDF file. Inside the templates you may also include HTML elements with the following classes and values will be automatically injected into them:

• .date - formatted print date;
• .pageNumber - current page number;
• .totalPages - total number of pages in the document.

Note that Puppeteer's template classes .title and .url are useless for the tool, as the PDF file is generated on one web page and these values will be the same on all document pages. However, you may still use them in your template, if necessary.

Some things to keep in mind:

• The template must be a valid HTML structure.
• You should define font-size property as Puppeteer's default value is 0.
• Use inline <style> tag to define your styles. Website styles are not available inside the templates.
• Images should be encoded as base64 strings.
• Use --margins and --paddings options to achieve the desired layout.

Check header-template.html and footer-template.html as valid examples.
You may also check the resulting PDF file.

Demo

🤖 GitHub Actions

To set up GitHub Actions, create a .github/workflows folder in the root of your project. Use the example YAML file for GitHub Actions provided. This file includes all the steps required to generate a PDF file, add it to the dist folder, and deploy your website to Netlify.

Key points:

• The workflow installs Chromium and specifies its executable path using the --browser-executable flag.

• In the example, the output folder is set to ./dist/_pdf, making the PDF accessible at https://your.website/_pdf/docs.pdf. Do not forget to change the --filename in the example YAML file.

• If your preview server uses a custom port, update the following steps in the YAML file accordingly:

  • Record preview server's process ID
  • Create PDF

• If your project has a custom build command, modify the YAML file to fit your workflow.

Deploying with Netlify

The example YAML assumes deployment to Netlify. If you use a different hosting provider, update the deployment steps to match your setup.

For Netlify, follow these steps:

1. Obtain your Netlify Auth Token from User settings.

2. Get your Site ID from Site page > Site configuration > Site details > Site information.

3. Add them as repository secrets under the names NETLIFY_AUTH_TOKEN and NETLIFY_SITE_ID. Check GitHub's guide for details.

Generating PDF locally

To generate a PDF file during local development, add the following command to your package.json:

"scripts": {
    "pdf": "npm run build && (npm run preview > /dev/null & sleep 5); lsof -ti:4321 > preview.pid; npx starlight-to-pdf http://localhost:4321 -p ./public/_pdf --filename docs --pdf-outline; kill $(cat preview.pid) && rm preview.pid && echo 'PDF script finished'"
}

This script will generate the PDF and save it in the public/_pdf folder.

Note, if your preview server uses a non-default port, or your project requires a custom build command, update the script accordingly.

📨 Contacts

If you want to get in touch, you may open a GitHub issue or email me at: [email protected].

🪪 License

starlight-to-pdf is licensed under the MIT License. See the LICENSE file for details.