react

NOTE

You're probably looking for react-collapsed. This package (alongside @collapsed/core) is a WIP rewrite to create a Vanilla JS core.

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@collapsed/react (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 @collapsed/react

Usage

Simple Usage

import React from "react";
import { useCollapse } from "@collapsed/react";

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 "@collapsed/react";

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

useCollapse takes the following options:

interface UseCollapseOptions {
  /** If true, the disclosure is expanded. */
  isExpanded?: boolean;
  /**
   * If true, the disclosure is expanded when it initially mounts.
   * @default false
   */
  defaultExpanded?: boolean;
  /** Handler called when the disclosure expands or collapses */
  onExpandedChange?: (state: boolean) => void;
  /** Handler called at each stage of the animation. */
  onTransitionStateChange?: (
    state:
      | "expandStart"
      | "expanding"
      | "expandEnd"
      | "collapseStart"
      | "collapsing"
      | "collapseEnd",
  ) => void;
  /** Timing function for the transition */
  easing?: string;
  /**
   * Duration of the expand/collapse animation.
   * If 'auto', the duration will be calculated based on the height of the collapse element
   */
  duration?: "auto" | number;
  /** Height in pixels that the collapse element collapses to */
  collapsedHeight?: number;
  /**
   * Unique identifier used to for associating elements appropriately for accessibility.
   */
  id?: string;
}

And returns the following API:

interface CollapseAPI {
  isExpanded: boolean;
  setExpanded: (update: boolean | ((prev: boolean) => boolean)) => void;
  getToggleProps: <T extends HTMLElement>(
    props?: React.ComponentPropsWithoutRef<T> & { refKey?: string },
  ) => React.ComponentPropsWithRef<T>;
  getCollapseProps: <T extends HTMLElement>(
    props?: React.ComponentPropsWithoutRef<T> & { refKey?: string },
  ) => React.ComponentPropsWithRef<T>;
}

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>