Part 3 / Transitions / Custom JS transitions
While you should generally use CSS for transitions as much as possible, there are some effects that can't be achieved without JavaScript, such as a typewriter effect:
function typewriter(node, { speed = 1 }) {
const valid = node.childNodes.length === 1 && node.childNodes[0].nodeType === Node.TEXT_NODE;
if (!valid) {
throw new Error(`This transition only works on elements with a single text node child`);
}
const text = node.textContent;
const duration = text.length / (speed * 0.01);
return {
duration,
tick: (t) => {
const i = Math.trunc(text.length * t);
node.textContent = text.slice(0, i);
}
};
}
initialising