minor improvement

site/content/tutorial/12-actions/02-adding-parameters-to-actions/app-a/tooltip.js

@@ -0,0 +1,49 @@
+export function tooltip(node, text) {
+		const tooltip = document.createElement('div');
+		tooltip.textContent = text;
+
+		Object.assign(tooltip.style, {
+			position: 'absolute',
+			background: 'black',
+			color: 'white',
+			padding: '0.5em 1em',
+			fontSize: '12px',
+			pointerEvents: 'none',
+			transform: 'translate(5px, -50%)',
+			borderRadius: '2px',
+			transition: 'opacity 0.4s'
+		});
+
+		function position() {
+			const { top, right, bottom } = node.getBoundingClientRect();
+			tooltip.style.top = `${(top + bottom) / 2}px`;
+			tooltip.style.left = `${right}px`;
+		}
+
+		function append() {
+			document.body.appendChild(tooltip);
+			tooltip.style.opacity = 0;
+			setTimeout(() => tooltip.style.opacity = 1);
+			position();
+		}
+
+		function remove() {
+			tooltip.remove();
+		}
+
+		node.addEventListener('mouseenter', append);
+		node.addEventListener('mouseleave', remove);
+
+		return {
+			update(text) {
+				tooltip.textContent = text;
+				position();
+			},
+
+			destroy() {
+				tooltip.remove();
+				node.removeEventListener('mouseenter', append);
+				node.removeEventListener('mouseleave', remove);
+			}
+		};
+	}