CSS Transition Not Working as Expected When Adding New Elements Dynamically
Quick question that's been bugging me - I'm working on a project and hit a roadblock. I've been banging my head against this for hours. I'm trying to implement a smooth fade-in transition for elements that are being dynamically added to the DOM using React 17. I have a simple component that maps over an array of items and renders them with a CSS class that includes a transition effect. However, when I add a new item, the transition does not occur as expected; instead, the new item appears instantly without any fading effect. Here's the relevant CSS for the transition: ```css .fade-in { opacity: 0; transition: opacity 0.5s ease-in; } .fade-in.visible { opacity: 1; } ``` And here's the React component code: ```javascript import React, { useState } from 'react'; const FadeInList = () => { const [items, setItems] = useState(["Item 1", "Item 2"]); const addItem = () => { setItems([...items, `Item ${items.length + 1}`]); }; return ( <div> <button onClick={addItem}>Add Item</button> <ul> {items.map((item, index) => ( <li key={index} className={`fade-in ${index === items.length - 1 ? 'visible' : ''}`}>{item}</li> ))} </ul> </div> ); }; export default FadeInList; ``` When I click the 'Add Item' button, the new item simply appears without the fade-in effect. I've tried ensuring that the `visible` class is added after the state update, but that doesn't seem to help. My browser's console logs don't show any errors related to this. Any idea why the transition isn't triggering correctly, or how I can fix this? Iām using Chrome 116 for testing. This is part of a larger service I'm building. Has anyone else encountered this? I'm using Javascript 3.11 in this project. Any suggestions would be helpful. My development environment is Linux. Any help would be greatly appreciated! Thanks, I really appreciate it!