How do I make a div expand smoothly when content is added?
const [render, setRender] = useState(false)
const showHide= () => {
setRender(!render)
}
return (
<div className="container">
<h1>TEST CONTAINER</h1>
{render && <Paragprah />}
<button type="button" class="btn btn-primary" onClick={showHide}>Primary</button>
</div>
);
}
CSS
.container {
margin-left: 30%;
margin-top: 10%;
width: 500px;
height: auto;
background-color: whitesmoke;
}
In the above, a component is being rendered when a button is clicked, when the new content is added to the div, it expands instantly. basically, I would like it to expand smoothly when the content is added. Here is a video as well by what I mean when it expands instantly.
Setting a fixed height wont work in my situation because the content that's being loaded is dynamic, its coming from an API and the length is different everytime. So setting a fixed height will make the content overflow sometimes. I need a way where the transition can occur smoothly and the height still be large enough to fit the content, which would probably require ```height: auto;`` to be present?
Here I updated the code. Since the content that's being loaded has dynamic size then you have to track that content size using useRef hook and store it on a variable and export it with your component.
import { useRef, useEffect} from "react";
var ParagraphHeight;
function Paragraph() {
const ref = useRef(null);
useEffect(() => {
//when you content is loaded store its height
ParagraphHeight = ref.current.offsetHeight;
}, []);
return (
<div ref={ref}>
<p>Your content here for exemple...</p>
</div>
);
}
export { Paragraph, ParagraphHeight };
Now import your Paragraph component and put it inside a .wrapper div that has a default height of 0px (that means your Paragraph will be hidden) and when you click on the button the height of it will change to the ParagraphHeight
import { useState } from "react";
import { Paragraph, ParagraphHeight } from "./Paragraph.js";
export default function App() {
const [isopned, setisopned] = useState(false);
const [wrapperHeight, setWH] = useState(0);
const showHide = () => {
if (!isopned) setWH(ParagraphHeight);
else setWH(0);
setisopned(!isopned);
};
return (
<div className="container">
<h1>TEST CONTAINER</h1>
<div className="wrapper" style={{ height: wrapperHeight }}>
<Paragraph />
</div>
<button type="button" className="btn btn-primary" onClick={showHide}>
Primary
</button>
</div>
);
}
Finally don't forget to update your css, add overflow-y hidden and css transition to to expand your wrapper div smoothly.
.container {
margin-left: 30%;
margin-top: 10%;
width: 500px;
background-color: whitesmoke;
}
.wrapper {
display: grid; /*to prevent some problem caused by overflow hidden*/
transition: height 1s linear;
background-color: wheat;
overflow-y: hidden;
}
This is a live exemple demo