Browser CSS Page Transitions API aka Shared Element Transitions

In this Hasty Treat, Scott and Wes talk about the new Browser CSS Page Transitions API proposal and what features it opens up for developers on the web.

Prismic - Sponsor

Prismic is a Headless CMS that makes it easy to build website pages as a set of components. Break pages into sections of components using React, Vue, or whatever you like. Make corresponding Slices in Prismic. Start building pages dynamically in minutes. Get started at prismic.io/syntax.

LogRocket - Sponsor

LogRocket lets you replay what users do on your site, helping you reproduce bugs and fix issues faster. It’s an exception tracker, a session re-player and a performance monitor. Get 14 days free at logrocket.com/syntax.

Show Notes

• WICG Shared Element Transitions

• 00:21 Welcome

• 01:33 Sponsor: Prismic

• 02:43 Sponsor: LogRocket

• 04:18 Browser animations on the web vs native apps

• 06:15 What is the targeted use case for it?

• 06:56 Shared Element to Root Transitions

• 11:14 Entry and Exit

• 17:33 How to enable this in Chrome

• Example Code

• Shared Element Transition history

• Sarah Drasner’s demo

async function doTransition() { let transition = document.createDocumentTransition(); // Specify offered elements. The tag below is used to refer // to the generated pseudo elemends in script/CSS. document.querySelector(".old-message").style.pageTransitionTag = "message"; // The start() call triggers an async operation to capture // snapshots for the offered elements, await transition.start(async () => { // This callback is invoked by the browser when the capture // finishes and the DOM can be switched to the new state. // No frames are rendered until this callback returns. // Asynchronously load the new page. await coolFramework.changeTheDOMToPageB(); // Clear the old message if that element is still in the page document.querySelector(".old-message").style.pageTransitionTag = ""; // Set new message as the shared element 'message' document.querySelector(".new-message").style.pageTransitionTag = "message"; // Set up animations using WA-API on the next frame. requestAnimationFrame(() => { document.documentElement.animate(keyframes, { ...animationOptions, pseudoElement: "::page-transition-container(message)", }); }); // Note that when this callback finishes, the animations will start with the tagged elements. }); } Tweet us your tasty treats

• Scott’s Instagram
• LevelUpTutorials Instagram
• Wes’ Instagram
• Wes’ Twitter
• Wes’ Facebook
• Scott’s Twitter
• Make sure to include @SyntaxFM in your tweets