README.md

🙈 react-collapsed (useCollapse)

A React hook for creating accessible expand/collapse components. Animates the height using CSS transitions from 0 to auto.

Features

• Handles the height of animations of your elements, auto included!
• You control the UI - useCollapse provides the necessary props, you control the styles and the elements.
• Accessible out of the box - no need to worry if your collapse/expand component is accessible, since this takes care of it for you!
• No animation framework required! Simply powered by CSS animations
• Written in TypeScript

Demo

See the demo site!

CodeSandbox demo

Installation

$ npm i react-collapsed

Usage

Simple Usage

import React from "react";
import { useCollapse } from "react-collapsed";

function Demo() {
  const { getCollapseProps, getToggleProps, isExpanded } = useCollapse();

  return (
    <div>
      <button {...getToggleProps()}>
        {isExpanded ? "Collapse" : "Expand"}
      </button>
      <section {...getCollapseProps()}>Collapsed content 🙈</section>
    </div>
  );
}

Control it yourself

import React, { useState } from "react";
import { useCollapse } from "react-collapsed";

function Demo() {
  const [isExpanded, setExpanded] = useState(false);
  const { getCollapseProps, getToggleProps } = useCollapse({ isExpanded });

  return (
    <div>
      <button
        {...getToggleProps({
          onClick: () => setExpanded((prevExpanded) => !prevExpanded),
        })}
      >
        {isExpanded ? "Collapse" : "Expand"}
      </button>
      <section {...getCollapseProps()}>Collapsed content 🙈</section>
    </div>
  );
}

API

const { getCollapseProps, getToggleProps, isExpanded, setExpanded } =
  useCollapse({
    isExpanded: boolean,
    defaultExpanded: boolean,
    collapsedHeight: 0,
    easing: string,
    duration: number,
    onTransitionStateChange: func,
  });

useCollapse Config

The following are optional properties passed into useCollapse({ }):

Prop	Type	Default	Description
isExpanded	boolean	undefined	If true, the Collapse is expanded
defaultExpanded	boolean	false	If true, the Collapse will be expanded when mounted
collapsedHeight	number	0	The height of the content when collapsed
easing	string	cubic-bezier(0.4, 0, 0.2, 1)	The transition timing function for the animation
duration	number	undefined	The duration of the animation in milliseconds. By default, the duration is programmatically calculated based on the height of the collapsed element
onTransitionStateChange	function	no-op	Handler called with at each stage of the transition animation
hasDisabledAnimation	boolean	false	If true, will disable the animation
id	string | number	undefined	Unique identifier used to for associating elements appropriately for accessibility.

What you get

Name	Description
getCollapseProps	Function that returns a prop object, which should be spread onto the collapse element
getToggleProps	Function that returns a prop object, which should be spread onto an element that toggles the collapse panel
isExpanded	Whether or not the collapse is expanded (if not controlled)
setExpanded	Sets the hook's internal isExpanded state

Alternative Solutions

• react-spring - JavaScript animation based library that can potentially have smoother animations. Requires a bit more work to create an accessible collapse component.
• react-animate-height - Another library that uses CSS transitions to animate to any height. It provides components, not a hook.

FAQ

When I apply vertical padding to the component that gets getCollapseProps, the animation is janky and it doesn't collapse all the way. What gives?

The collapse works by manipulating the height property. If an element has vertical padding, that padding expandes the size of the element, even if it has height: 0; overflow: hidden.

To avoid this, simply move that padding from the element to an element directly nested within in.

// from
<div {...getCollapseProps({style: {padding: 20}})}
  This will do weird things
</div>

// to
<div {...getCollapseProps()}
  <div style={{padding: 20}}>
    Much better!
  </div>
</div>