wendyzhaogogo/react-transition-state

Zero dependency React transition state machine

React-Transition-State

Features

Inspired by the React Transition Group, this tiny library helps you easily perform animations/transitions of your React component in a fully controlled manner, using a Hook API.

• 🍭 Working with both CSS animation and transition.
• 🔄 Moving React components in and out of DOM seamlessly.
• 🚫 Using no derived state.
• 🚀 Efficient: each state transition results in at most one extract render for consuming component.
• 🤏 Tiny: ~1KB(post-treeshaking) and no dependencies, ideal for both component libraries and applications.

🤔 Not convinced? See a comparison with React Transition Group

State diagram

The initialEntered and mountOnEnter props are omitted from the diagram to keep it less convoluted. Please read more details at the API section.

Install

# with npm
npm install react-transition-state

# with Yarn
yarn add react-transition-state

Usage

CSS example

import { useTransition } from 'react-transition-state';
/* or import useTransition from 'react-transition-state'; */

function Example() {
  const [state, toggle] = useTransition({ timeout: 750, preEnter: true });
  return (
    <div>
      <button onClick={() => toggle()}>toggle</button>
      <div className={`example ${state.status}`}>React transition state</div>
    </div>
  );
}

export default Example;

.example {
  transition: all 0.75s;
}

.example.preEnter,
.example.exiting {
  opacity: 0;
  transform: scale(0.5);
}

.example.exited {
  display: none;
}

Edit on CodeSandbox

styled-components example

import styled from 'styled-components';
import { useTransition } from 'react-transition-state';

const Box = styled.div`
  transition: all 500ms;

  ${({ $status }) =>
    ($status === 'preEnter' || $status === 'exiting') &&
    `
      opacity: 0;
      transform: scale(0.9);
    `}
`;

function StyledExample() {
  const [{ status, isMounted }, toggle] = useTransition({
    timeout: 500,
    mountOnEnter: true,
    unmountOnExit: true,
    preEnter: true
  });

  return (
    <div>
      {!isMounted && <button onClick={() => toggle(true)}>Show Message</button>}
      {isMounted && (
        <Box $status={status}>
          <p>This message is being transitioned in and out of the DOM.</p>
          <button onClick={() => toggle(false)}>Close</button>
        </Box>
      )}
    </div>
  );
}

export default StyledExample;

Edit on CodeSandbox

tailwindcss example

Edit on CodeSandbox

Perform appearing transition when page loads or a component mounts

You can toggle on transition with the useEffect hook.

useEffect(() => {
  toggle(true);
}, [toggle]);

Edit on CodeSandbox

Comparisons with React Transition Group

	React Transition Group	This library
Use derived state	Yes – use an in prop to trigger changes in a derived transition state	No – there is only a single state which is triggered by a toggle function
Controlled	No – Transition state is managed internally. Resort to callback events to read the internal state.	Yes – Transition state is lifted up into the consuming component. You have direct access to the transition state.
DOM updates	Imperative – commit changes into DOM imperatively to update classes	Declarative – you declare what the classes look like and DOM updates are taken care of by ReactDOM
Render something in response to state updates	Resort to side effects – rendering based on state update events	Pure – rendering based on transition state
Working with styled-components	Your code looks like – &.box-exit-active { opacity: 0; } &.box-enter-active { opacity: 1; }	Your code looks like – opacity: ${({ state }) => (state === 'exiting' ? '0' : '1')}; It's the way how you normally use the styled-components
Bundle size		✅
Dependency count		✅

This CodeSandbox example demonstrates how the same transition can be implemented in a simpler, more declarative, and controllable manner than React Transition Group.

API

useTransition Hook

function useTransition(
  options?: TransitionOptions
): [TransitionState, (toEnter?: boolean) => void, () => void];

Options

Name	Type	Default	Description
enter	boolean	true	Enable or disable enter phase transitions
exit	boolean	true	Enable or disable exit phase transitions
preEnter	boolean		Add a 'preEnter' state immediately before 'entering', which is necessary to change DOM elements from unmounted or display: none with CSS transition (not necessary for CSS animation).
preExit	boolean		Add a 'preExit' state immediately before 'exiting'
initialEntered	boolean		Beginning from 'entered' state
mountOnEnter	boolean		State will be 'unmounted' until hit enter phase for the first time. It allows you to create lazily mounted component.
unmountOnExit	boolean		State will become 'unmounted' after 'exiting' finishes. It allows you to transition component out of DOM.
timeout	number | { enter?: number; exit?: number; }		Set timeout in ms for transitions; you can set a single value or different values for enter and exit transitions.
onStateChange	(event: { current: TransitionState }) => void		Event fired when state has changed. Prefer to read state from the hook function return value directly unless you want to perform some side effects in response to state changes. Note: create an event handler with useCallback if you need to keep toggle or endTransition function's identity stable across re-renders.

Return value

The useTransition Hook returns a tuple of values in the following order:

1. state:

{
  status: 'preEnter' |
    'entering' |
    'entered' |
    'preExit' |
    'exiting' |
    'exited' |
    'unmounted';
  isMounted: boolean;
  isEnter: boolean;
  isResolved: boolean;
}

2. toggle: (toEnter?: boolean) => void

• If no parameter is supplied, this function will toggle state between enter and exit phases.
• You can set a boolean parameter to explicitly switch into one of the two phases.

3. endTransition: () => void

• Call this function to stop transition which will turn state into 'entered' or 'exited'.
• You will normally call this function in the onAnimationEnd or onTransitionEnd event.
• You need to either call this function explicitly in your code or set a timeout value in Hook options.

useTransitionMap Hook

It's similar to the useTransition Hook except that it manages multiple states in a Map structure instead of a single state.

Options

It accepts all options as useTransition and the following ones:

Name	Type	Default	Description
allowMultiple	boolean		Allow multiple items to be in the enter phase at the same time.

Return value

The Hook returns an object of shape:

interface TransitionMapResult<K> {
  stateMap: ReadonlyMap<K, TransitionState>;
  toggle: (key: K, toEnter?: boolean) => void;
  toggleAll: (toEnter?: boolean) => void;
  endTransition: (key: K) => void;
  setItem: (key: K, options?: TransitionItemOptions) => void;
  deleteItem: (key: K) => boolean;
}

setItem and deleteItem are used to add and remove items from the state map.

License

MIT Licensed.