Stanko
React Animate Height
Lightweight React component for animating height using CSS transitions.
Slide an element up and down or animate it to any specific height.
Content's opacity can be optionally animated as well (check animateOpacity prop bellow).
CSS classes are applied in specific animation states, check animationStateClasses prop.
Note about versions
For React >=16.3.0 make sure you are using v2.x.
Read more about React lifecycle changes introduced with React 16.3.
Demo
Live demo: muffinman.io/react-animate-height
Because multiple people asked how to animate list items, I created this simple example for that as well.
To build the examples locally, run:
npm install
npm startThen open localhost:8080 in your browser of choice browser.
Or play with this sandbox.
Quick start
Get it from npm
$ npm install --save react-animate-heightImport and use it in your React app.
import React, { Component } from "react";
import AnimateHeight from "react-animate-height";
export default class Example extends Component {
state = {
height: 0,
};
toggle = () => {
const { height } = this.state;
this.setState({
height: height === 0 ? "auto" : 0,
});
};
render() {
const { height } = this.state;
return (
<div>
<button
aria-expanded={height !== 0}
aria-controls="example-panel"
onClick={this.toggle}
>
{height === 0 ? "Open" : "Close"}
</button>
<AnimateHeight
id="example-panel"
duration={500}
height={height} // see props documentation below
>
<h1>Your content goes here</h1>
<p>Put as many React or HTML components here.</p>
</AnimateHeight>
</div>
);
}
}Props
height: numeric or percentage value (ie.
'50%') or'auto', requiredWhen changed, element height will be animated to that height.
To slide up use0, for slide down use'auto'duration: integer, default:
250Duration of the animation in milliseconds
delay: integer, default:
0Animation delay in milliseconds
easing: string, default:
'ease'CSS easing function to be applied to the animation
id: string
HTML
idattribute.className: string
CSS class to be applied to the element
Please note that you shouldn't apply properties that are messing with the layout (like
display,height...), as these might break height calculationsstyle: object
CSS style object, it will be merged with inline styles of the component
Please note that you shouldn't apply properties that are messing with the layout (like
display,height...), as these might break height calculationscontentClassName: string
CSS class to be applied to content wrapper element
Please note that you shouldn't apply properties that are messing with the layout (like
display,height...), as these might break height calculationsanimationStateClasses: object
Object containing CSS class names for animation states, default:
{ animating: 'rah-animating', animatingUp: 'rah-animating--up', animatingDown: 'rah-animating--down', static: 'rah-static', animatingToHeightZero: 'rah-animating--to-height-zero', animatingToHeightAuto: 'rah-animating--to-height-auto', animatingToHeightSpecific: 'rah-animating--to-height-specific', staticHeightZero: 'rah-static--height-zero', staticHeightAuto: 'rah-static--height-auto', staticHeightSpecific: 'rah-static--height-specific', }Please note that this one will be merged with the default object and cached when component is created, so changing it afterwards will have no effect.
onAnimationStart: function
Callback which will be called when animation starts.
This first argument passed to this callback is an object containing
newHeight, the pixel value of the height at which the animation will end.onAnimationEnd: function
Callback which will be called when animation ends.
This first argument passed to this callback is an object containing
newHeight, the pixel value of the height at which the animation ended.applyInlineTransitions: boolean, default:
trueIf this flag is set to
falseonly CSS classes will be applied to the element and inline transition styles will not be present.animateOpacity: boolean, default:
falseIf set to
truecontent will fade-in (and fade-out) while height is animated.aria-hidden: boolean
By default, library will set
aria-hiddentotruewhen height is zero. If you wish to override it, you can pass the prop yourself.
Additional props will be passed to the wrapper div, to make adding attrs like aria-* easier.
Accessibility
Library will hide the content using display: hidden when height props is 0. It will also apply aria-hidden="true" in the same case, but you can override it by passing aria-hidden prop yourself.
When using a button to toggle height, make sure you add aria-expanded and aria-controls to make everything accessible. Here's an example:
<button
aria-expanded={ height !== 0 }
aria-controls='example-panel' // it has to match the id passed to AnimateHeight
onClick={ toggleHeight } // your click handler that toggles height
// ... all other props
>
Toggle
</button>
<AnimateHeight id='example-panel'>
Content
</AnimateHeight>Reduced motion
Component checks for prefers-reduced-motion in the constructor and disables animations if it set to true. Please note that component doesn't listen for potential changes of prefers-reduced-motion option.
Gotchas
Bounded flexboxes
If AnimateHeight is a flex child and it's parent has a fixed height, animation won't work.
To fix this, you just need to add the following CSS rule to the AnimateHeight instance.
flex-shrink: 0;You can do it by passing a className or directly in the style prop
<AnimateHeight style={{flexShrink: 0}}>Check the issue #89 for the example and more details.