JavaScript print Events

Media queries provide a great way to programmatically change behavior depending on viewing state. We can target styles to device, pixel ratio, screen size, and even print. That said, it's also nice to have JavaScript events that also allow us to change behavior. Did you know you're provided events both before and after printing?

I've always used @media print in stylesheets to control print display, but JavaScript provides beforeprint and afterprint events:

function toggleImages(hide = false) {
  document.querySelectorAll('img').forEach(img => {
    img.style.display = hide ? 'none' : '';
  });
}

// Hide images to save toner/ink during printing
window.addEventListener('beforeprint', () => toggleImages(true))
window.addEventListener('afterprint', () => toggleImages());

It may sound weird but considering print is very important, especially when your website is documentation-centric. In my early days of web, I had a client who only "viewed" their website from print-offs. Styling with @media print is usually the best options but these JavaScript events may help!