👀 Views: 18 💬 Answers: 1 📅 Created: 2025-07-18

css react transition javascript

I'm reviewing some code and I've looked through the documentation and I'm still confused about I'm working with an scenario where a CSS transition isn't applied when the size of a dynamically rendered element changes in my React 18 application. I have a component that toggles a state causing a div to expand or collapse based on a button click. The question is, although the size changes, the transition effect doesn't trigger as expected. I’m using the following styles for the transition: ```css .expand { transition: height 0.5s ease; overflow: hidden; } .collapse { height: 0; } .expand.show { height: 100px; /* Desired height when expanded */ } ``` In my component, I toggle the class like this: ```javascript import React, { useState } from 'react'; const ToggleComponent = () => { const [isExpanded, setIsExpanded] = useState(false); return ( <div> <button onClick={() => setIsExpanded(!isExpanded)}>Toggle</button> <div className={`expand ${isExpanded ? 'show' : 'collapse'}`}>Content goes here</div> </div> ); }; export default ToggleComponent; ``` Despite updating the class based on the state, the transition doesn't occur. In the developer tools, I can see the class changes on the element, but the `height` property doesn't animate as expected. I've also tried using `max-height` instead of `height`, but the transition still fails to show up. I’ve confirmed that the transition works when I apply it directly with static elements, but the dynamic nature of React seems to be causing a conflict. Has anyone else experienced this or have suggestions on how to properly implement transitions for dynamically sized elements in React? This is part of a larger web app I'm building. Am I missing something obvious? This issue appeared after updating to Javascript 3.10. Any pointers in the right direction? I'm developing on Ubuntu 20.04 with Javascript.