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https://github.com/charkour/zundo
π undo/redo middleware for zustand. <700 bytes
https://github.com/charkour/zundo
middleware redo undo zustand
Last synced: about 11 hours ago
JSON representation
π undo/redo middleware for zustand. <700 bytes
- Host: GitHub
- URL: https://github.com/charkour/zundo
- Owner: charkour
- License: mit
- Created: 2021-04-02T00:54:29.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2025-01-19T18:39:52.000Z (11 days ago)
- Last Synced: 2025-01-23T10:04:49.960Z (7 days ago)
- Topics: middleware, redo, undo, zustand
- Language: TypeScript
- Homepage: https://codesandbox.io/s/zundo-2dom9
- Size: 2.81 MB
- Stars: 671
- Watchers: 7
- Forks: 22
- Open Issues: 12
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
# π Zundo
enable time-travel in your apps. undo/redo middleware for [zustand](https://github.com/pmndrs/zustand). built with zustand. <700 B
[](https://bundlephobia.com/result?p=zundo)
[](https://www.npmjs.com/package/zundo)
[](https://www.npmjs.com/package/zundo)
Try a live [demo](https://codesandbox.io/s/currying-flower-2dom9?file=/src/App.tsx)
## Install
```sh
npm i zustand zundo
```
> zustand v4.2.0+ or v5 is required for TS usage. v4.0.0 or higher is required for JS usage.
> Node 16 or higher is required.
## Background
- Solves the issue of managing state in complex user applications
- "It Just Works" mentality
- Small and fast
- Provides simple middleware to add undo/redo capabilities
- Leverages zustand for state management
- Works with multiple stores in the same app
- Has an unopinionated and extensible API
## First create a vanilla store with `temporal` middleware
This returns the familiar store accessible by a hook! But now your store also tracks past states.
```tsx
import { create } from 'zustand';
import { temporal } from 'zundo';
// Define the type of your store state (typescript)
interface StoreState {
bears: number;
increasePopulation: () => void;
removeAllBears: () => void;
}
// Use `temporal` middleware to create a store with undo/redo capabilities
const useStoreWithUndo = create()(
temporal((set) => ({
bears: 0,
increasePopulation: () => set((state) => ({ bears: state.bears + 1 })),
removeAllBears: () => set({ bears: 0 }),
})),
);
```
## Then access `temporal` functions and properties of your store
Your zustand store will now have an attached `temporal` object that provides access to useful time-travel utilities, including `undo`, `redo`, and `clear`!
```tsx
const App = () => {
const { bears, increasePopulation, removeAllBears } = useStoreWithUndo();
// See API section for temporal.getState() for all functions and
// properties provided by `temporal`, but note that properties, such as `pastStates` and `futureStates`, are not reactive when accessed directly from the store.
const { undo, redo, clear } = useStoreWithUndo.temporal.getState();
return (
<>
bears: {bears}
increasePopulation}>increase
removeAllBears}>remove
undo()}>undo
redo()}>redo
clear()}>clear
>
);
};
```
## For reactive changes to member properties of the `temporal` object, optionally convert to a React store hook
In React, to subscribe components or custom hooks to member properties of the `temporal` object (like the array of `pastStates` or `currentStates`), you can create a `useTemporalStore` hook.
```tsx
import { useStoreWithEqualityFn } from 'zustand/traditional';
import type { TemporalState } from 'zundo';
function useTemporalStore(): TemporalState;
function useTemporalStore(selector: (state: TemporalState) => T): T;
function useTemporalStore(
selector: (state: TemporalState) => T,
equality: (a: T, b: T) => boolean,
): T;
function useTemporalStore(
selector?: (state: TemporalState) => T,
equality?: (a: T, b: T) => boolean,
) {
return useStoreWithEqualityFn(useStoreWithUndo.temporal, selector!, equality);
}
const App = () => {
const { bears, increasePopulation, removeAllBears } = useStoreWithUndo();
// changes to pastStates and futureStates will now trigger a reactive component rerender
const { undo, redo, clear, pastStates, futureStates } = useTemporalStore(
(state) => state,
);
return (
<>
bears: {bears}
pastStates: {JSON.stringify(pastStates)}
futureStates: {JSON.stringify(futureStates)}
increasePopulation}>increase
removeAllBears}>remove
undo()}>undo
redo()}>redo
clear()}>clear
>
);
};
```
## API
### The Middleware
`(config: StateCreator, options?: ZundoOptions) => StateCreator`
`zundo` has one export: `temporal`. It is used as middleware for `create` from zustand. The `config` parameter is your store created by zustand. The second `options` param is optional and has the following API.
### Bear's eye view
```tsx
export interface ZundoOptions {
partialize?: (state: TState) => PartialTState;
limit?: number;
equality?: (pastState: PartialTState, currentState: PartialTState) => boolean;
diff?: (
pastState: Partial,
currentState: Partial,
) => Partial | null;
onSave?: (pastState: TState, currentState: TState) => void;
handleSet?: (
handleSet: StoreApi['setState'],
) => StoreApi['setState'];
pastStates?: Partial[];
futureStates?: Partial[];
wrapTemporal?: (
storeInitializer: StateCreator<
_TemporalState,
[StoreMutatorIdentifier, unknown][],
[]
>,
) => StateCreator<
_TemporalState,
[StoreMutatorIdentifier, unknown][],
[StoreMutatorIdentifier, unknown][]
>;
}
```
### Exclude fields from being tracked in history
`partialize?: (state: TState) => PartialTState`
Use the `partialize` option to omit or include specific fields. Pass a callback that returns the desired fields. This can also be used to exclude fields. By default, the entire state object is tracked.
```tsx
// Only field1 and field2 will be tracked
const useStoreWithUndoA = create()(
temporal(
(set) => ({
// your store fields
}),
{
partialize: (state) => {
const { field1, field2, ...rest } = state;
return { field1, field2 };
},
},
),
);
// Everything besides field1 and field2 will be tracked
const useStoreWithUndoB = create()(
temporal(
(set) => ({
// your store fields
}),
{
partialize: (state) => {
const { field1, field2, ...rest } = state;
return rest;
},
},
),
);
```
#### `useTemporalStore` with `partialize`
If converting temporal store to a React Store Hook with typescript, be sure to define the type of your partialized state
```tsx
interface StoreState {
bears: number;
untrackedStateField: number;
}
type PartializedStoreState = Pick;
const useStoreWithUndo = create()(
temporal(
(set) => ({
bears: 0,
untrackedStateField: 0,
}),
{
partialize: (state) => {
const { bears } = state;
return { bears };
},
},
),
);
const useTemporalStore = (
// Use partalized StoreState type as the generic here
selector: (state: TemporalState) => T,
) => useStore(useStoreWithUndo.temporal, selector);
```
### Limit number of historical states stored
`limit?: number`
For performance reasons, you may want to limit the number of previous and future states stored in history. Setting `limit` will limit the number of previous and future states stored in the `temporal` store. When the limit is reached, the oldest state is dropped. By default, no limit is set.
```tsx
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{ limit: 100 },
),
);
```
### Prevent unchanged states from getting stored in history
`equality?: (pastState: PartialTState, currentState: PartialTState) => boolean`
By default, a state snapshot is stored in `temporal` history when _any_ `zustand` state setter is calledβeven if no value in your `zustand` store has changed.
If all of your `zustand` state setters modify state in a way that you want tracked in history, this default is sufficient.
However, for more precise control over when a state snapshot is stored in `zundo` history, you can provide an `equality` function.
You can write your own equality function or use something like [`fast-equals`](https://github.com/planttheidea/fast-equals), [`fast-deep-equal`](https://github.com/epoberezkin/fast-deep-equal), [`zustand/shallow`](https://github.com/pmndrs/zustand/blob/main/src/shallow.ts), [`lodash.isequal`](https://www.npmjs.com/package/lodash.isequal), or [`underscore.isEqual`](https://github.com/jashkenas/underscore/blob/master/modules/isEqual.js).
#### Example with deep equality
```tsx
import isDeepEqual from 'fast-deep-equal';
// Use a deep equality function to only store history when currentState has changed
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
// a state snapshot will only be stored in history when currentState is not deep-equal to pastState
// Note: this can also be more concisely written as {equality: isDeepEqual}
{
equality: (pastState, currentState) =>
isDeepEqual(pastState, currentState),
},
),
);
```
#### Example with shallow equality
If your state or specific application does not require deep equality (for example, if you're only using non-nested primitives), you may for performance reasons choose to use a shallow equality fn that does not do deep comparison.
```tsx
import shallow from 'zustand/shallow';
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
// a state snapshot will only be stored in history when currentState is not deep-equal to pastState
// Note: this can also be more concisely written as {equality: shallow}
{
equality: (pastState, currentState) => shallow(pastState, currentState),
},
),
);
```
#### Example with custom equality
You can also just as easily use custom equality functions for your specific application
```tsx
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{
// Only track history when field1 AND field2 diverge from their pastState
// Why would you do this? I don't know! But you can do it!
equality: (pastState, currentState) =>
pastState.field1 !== currentState.field1 &&
pastState.field2 !== currentState.field2,
},
),
);
```
### Store state delta rather than full object
`diff?: (pastState: Partial, currentState: Partial) => Partial | null`
For performance reasons, you may want to store the state delta rather than the complete (potentially partialized) state object. This can be done by passing a `diff` function. The `diff` function should return an object that represents the difference between the past and current state. By default, the full state object is stored.
If `diff` returns `null`, the state change will not be tracked. This is helpful for a conditionally storing past states or if you have a `doNothing` action that does not change the state.
You can write your own or use something like [`microdiff`](https://github.com/AsyncBanana/microdiff), [`just-diff`](https://github.com/angus-c/just/tree/master/packages/collection-diff), or [`deep-object-diff`](https://github.com/mattphillips/deep-object-diff).
```tsx
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{
diff: (pastState, currentState) => {
const myDiff = diff(currentState, pastState);
const newStateFromDiff = myDiff.reduce(
(acc, difference) => {
type Key = keyof typeof currentState;
if (difference.type === 'CHANGE') {
const pathAsString = difference.path.join('.') as Key;
acc[pathAsString] = difference.value;
}
return acc;
},
{} as Partial,
);
return isEmpty(newStateFromDiff) ? null : newStateFromDiff;
},
},
),
);
```
### Callback when temporal store is updated
`onSave?: (pastState: TState, currentState: TState) => void`
Sometimes, you may need to call a function when the temporal store is updated. This can be configured using `onSave` in the options, or by programmatically setting the callback if you need lexical context (see the `TemporalState` API below for more information).
```tsx
import { shallow } from 'zustand/shallow';
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{ onSave: (state) => console.log('saved', state) },
),
);
```
### Cool-off period
```typescript
handleSet?: (handleSet: StoreApi['setState']) => (
pastState: Parameters['setState']>[0],
// `replace` will likely be deprecated and removed in the future
replace: Parameters['setState']>[1],
currentState: PartialTState,
deltaState?: Partial | null,
) => void
```
Sometimes multiple state changes might happen in a short amount of time and you only want to store one change in history. To do so, we can utilize the `handleSet` callback to set a timeout to prevent new changes from being stored in history. This can be used with something like [`throttle-debounce`](https://github.com/niksy/throttle-debounce), [`just-throttle`](https://github.com/angus-c/just/tree/master/packages/function-throttle), [`just-debounce-it`](https://github.com/angus-c/just/tree/master/packages/function-debounce), [`lodash.throttle`](https://www.npmjs.com/package/lodash.throttle), or [`lodash.debounce`](https://www.npmjs.com/package/lodash.debounce). This a way to provide middleware to the temporal store's setter function.
```tsx
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{
handleSet: (handleSet) =>
throttle((state) => {
console.info('handleSet called');
handleSet(state);
}, 1000),
},
),
);
```
### Initialize temporal store with past and future states
`pastStates?: Partial[]`
`futureStates?: Partial[]`
You can initialize the temporal store with past and future states. This is useful when you want to load a previous state from a database or initialize the store with a default state. By default, the temporal store is initialized with an empty array of past and future states.
> Note: The `pastStates` and `futureStates` do not respect the limit set in the options. If you want to limit the number of past and future states, you must do so manually prior to initializing the store.
```tsx
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{
pastStates: [{ field1: 'value1' }, { field1: 'value2' }],
futureStates: [{ field1: 'value3' }, { field1: 'value4' }],
},
),
);
```
### Wrap temporal store
`wrapTemporal?: (storeInitializer: StateCreator<_TemporalState, [StoreMutatorIdentifier, unknown][], []>) => StateCreator<_TemporalState, [StoreMutatorIdentifier, unknown][], [StoreMutatorIdentifier, unknown][]>`
You can wrap the temporal store with your own middleware. This is useful if you want to add additional functionality to the temporal store. For example, you can add `persist` middleware to the temporal store to persist the past and future states to local storage.
For a full list of middleware, see [zustand middleware](https://www.npmjs.com/package/lodash.debounce) and [third-party zustand libraries](https://github.com/pmndrs/zustand#third-party-libraries).
> Note: The `temporal` middleware can be added to the `temporal` store. This way, you could track the history of the history. π€―
```tsx
import { persist } from 'zustand/middleware';
const useStoreWithUndo = create()(
temporal(
(set) => ({
// your store fields
}),
{
wrapTemporal: (storeInitializer) =>
persist(storeInitializer, { name: 'temporal-persist' }),
},
),
);
```
### `useStore.temporal`
When using zustand with the `temporal` middleware, a `temporal` object is attached to your vanilla or React-based store. `temporal` is a vanilla zustand store: see [StoreApi from](https://github.com/pmndrs/zustand/blob/f0ff30f7c431f6bf25b3cb439d065a7e61355df4/src/vanilla.ts#L8) zustand for more details.
Use `temporal.getState()` to access to temporal store!
> While `setState`, `subscribe`, and `destroy` exist on `temporal`, you should not need to use them.
### `useStore.temporal.getState()`
`temporal.getState()` returns the `TemporalState` which contains `undo`, `redo`, and other helpful functions and fields.
```tsx
interface TemporalState {
pastStates: TState[];
futureStates: TState[];
undo: (steps?: number) => void;
redo: (steps?: number) => void;
clear: () => void;
isTracking: boolean;
pause: () => void;
resume: () => void;
setOnSave: (onSave: onSave) => void;
}
```
#### **Going back in time**
`pastStates: TState[]`
`pastStates` is an array of previous states. The most recent previous state is at the end of the array. This is the state that will be applied when `undo` is called.
#### **Forward to the future**
`futureStates: TState[]`
`futureStates` is an array of future states. States are added when `undo` is called. The most recent future state is at the end of the array. This is the state that will be applied when `redo` is called. The future states are the "past past states."
#### **Back it up**
`undo: (steps?: number) => void`
`undo`: call function to apply previous state (if there are previous states). Optionally pass a number of steps to undo to go back multiple state at once.
#### **Take it back now y'all**
`redo: (steps?: number) => void`
`redo`: call function to apply future state (if there are future states). Future states are "previous previous states." Optionally pass a number of steps to redo go forward multiple states at once.
#### **Remove all knowledge of time**
`clear: () => void`
`clear`: call function to remove all stored states from your undo store. Sets `pastStates` and `futureStates` to arrays with length of 0. _Warning:_ clearing cannot be undone.
**Dispatching a new state will clear all of the future states.**
#### **Stop and start history**
`isTracking: boolean`
`isTracking`: a stateful flag in the `temporal` store that indicates whether the `temporal` store is tracking state changes or not. Possible values are `true` or `false`. To programmatically pause and resume tracking, use `pause()` and `resume()` explained below.
#### **Pause tracking of history**
`pause: () => void`
`pause`: call function to pause tracking state changes. This will prevent new states from being stored in history within the temporal store. Sets `isTracking` to `false`.
#### **Resume tracking of history**
`resume: () => void`
`resume`: call function to resume tracking state changes. This will allow new states to be stored in history within the temporal store. Sets `isTracking` to `true`.
#### **Programmatically add middleware to the setter**
`setOnSave: (onSave: (pastState: State, currentState: State) => void) => void`
`setOnSave`: call function to set a callback that will be called when the temporal store is updated. This can be used to call the temporal store setter using values from the lexical context. This is useful when needing to throttle or debounce updates to the temporal store.
## Community
`zundo` is used by several projects and teams including [Alibaba](https://github.com/alibaba/x-render), [Dify.ai](https://github.com/langgenius/dify), [Stability AI](https://github.com/Stability-AI/StableStudio), [Yext](https://github.com/yext/studio), [KaotoIO](https://github.com/KaotoIO/kaoto-ui), and [NutSH.ai](https://github.com/SysCV/nutsh).
If this library is useful to you, please consider [sponsoring](https://github.com/sponsors/charkour) the project. Thank you!
PRs are welcome! [pnpm](https://pnpm.io/) is used as a package manager. Run `pnpm install` to install local dependencies. Thank you for contributing!
## Examples
- [Basic](https://codesandbox.io/s/currying-flower-2dom9?file=/src/App.tsx)
- [with lodash.debounce](https://codesandbox.io/s/zundo-handleset-debounce-nq7ml7?file=/src/App.tsx)
- [with just-debounce-it](https://codesandbox.io/p/sandbox/zundo-forked-9yp7df)
- [SubscribeWithSelector](https://codesandbox.io/s/zundo-with-subscribe-with-selector-forked-mug69t)
- [canUndo, canRedo, undoDepth, redoDepth](https://codesandbox.io/s/zundo-canundo-and-undodepth-l6jclx?file=/src/App.tsx:572-731)
- [with deep equal](https://codesandbox.io/p/sandbox/zundo-deep-equal-qg69lj)
- [with input](https://stackblitz.com/edit/vitejs-vite-jqngm9?file=src%2FApp.tsx)
- [with slices pattern](https://codesandbox.io/p/sandbox/pttx6c)
## Migrate from v1 to v2
Click to expand
## v2.0.0 - Smaller and more flexible
v2.0.0 is a complete rewrite of zundo. It is smaller and more flexible. It also has a smaller bundle size and allows you to opt into specific performance trade-offs. The API has changed slightly. See the [API](#api) section for more details. Below is a summary of the changes as well as steps to migrate from v1 to v2.
### Breaking Changes
#### Middleware Option Changes
- `include` and `exclude` options are now handled by the `partialize` option.
- `allowUnchanged` option is now handled by the `equality` option. By default, all state changes are tracked. In v1, we bundled `lodash.isequal` to handle equality checks. In v2, you are able to use any function.
- `historyDepthLimit` option has been renamed to `limit`.
- `coolOffDurationMs` option is now handled by the `handleSet` option by wrapping the setter function with a throttle or debounce function.
#### Import changes
- The middleware is called `temporal` rather than `undoMiddleware`.
### New Features
#### New Options
- `partialize` option to omit or include specific fields. By default, the entire state object is tracked.
- `limit` option to limit the number of previous and future states stored in history.
- `equality` option to use a custom equality function to determine when a state change should be tracked. By default, all state changes are tracked.
- `diff` option to store state delta rather than full object.
- `onSave` option to call a function when the temporal store is updated.
- `handleSet` option to throttle or debounce state changes.
- `pastStates` and `futureStates` options to initialize the temporal store with past and future states.
- `wrapTemporal` option to wrap the temporal store with middleware. The `temporal` store is a vanilla zustand store.
#### New `temporal.getState()` API
- `undo`, `redo`, and `clear` functions are now always defined. They can no longer be `undefined`.
- `undo()` and `redo()` functions now accept an optional `steps` parameter to go back or forward multiple states at once.
- `isTracking` flag, and `pause`, and `resume` functions are now available on the temporal store.
- `setOnSave` function is now available on the temporal store to change the `onSave` behavior after the store has been created.
### Migration Steps
1. Update zustand to v4.3.0 or higher
2. Update zundo to v2.0.0 or higher
3. Update your store to use the new API
4. Update imports
```diff
- import { undoMiddleware } from 'zundo';
+ import { temporal } from 'zundo';
```
- If you're using `include` or `exclude`, use the new `partialize` option
```tsx
// v1.6.0
// Only field1 and field2 will be tracked
const useStoreA = create()(
undoMiddleware(
set => ({ ... }),
{ include: ['field1', 'field2'] }
)
);
// Everything besides field1 and field2 will be tracked
const useStoreB = create()(
undoMiddleware(
set => ({ ... }),
{ exclude: ['field1', 'field2'] }
)
);
// v2.0.0
// Only field1 and field2 will be tracked
const useStoreA = create()(
temporal(
(set) => ({
// your store fields
}),
{
partialize: (state) => {
const { field1, field2, ...rest } = state;
return { field1, field2 };
},
},
),
);
// Everything besides field1 and field2 will be tracked
const useStoreB = create()(
temporal(
(set) => ({
// your store fields
}),
{
partialize: (state) => {
const { field1, field2, ...rest } = state;
return rest;
},
},
),
);
```
- If you're using `allowUnchanged`, use the new `equality` option
```tsx
// v1.6.0
// Use an existing `allowUnchanged` option
const useStore = create()(
undoMiddleware(
set => ({ ... }),
{ allowUnchanged: true }
)
);
// v2.0.0
// Use an existing equality function
import { shallow } from 'zustand/shallow'; // or use `lodash.isequal` or any other equality function
// Use an existing equality function
const useStoreA = create()(
temporal(
(set) => ({
// your store fields
}),
{ equality: shallow },
),
);
```
- If you're using `historyDepthLimit`, use the new `limit` option
```tsx
// v1.6.0
// Use an existing `historyDepthLimit` option
const useStore = create()(
undoMiddleware(
set => ({ ... }),
{ historyDepthLimit: 100 }
)
);
// v2.0.0
// Use `limit` option
const useStore = create()(
temporal(
(set) => ({
// your store fields
}),
{ limit: 100 },
),
);
```
- If you're using `coolOffDurationMs`, use the new `handleSet` option
```tsx
// v1.6.0
// Use an existing `coolOffDurationMs` option
const useStore = create()(
undoMiddleware(
set => ({ ... }),
{ coolOfDurationMs: 1000 }
)
);
// v2.0.0
// Use `handleSet` option
const withTemporal = temporal(
(set) => ({
// your store fields
}),
{
handleSet: (handleSet) =>
throttle((state) => {
console.info('handleSet called');
handleSet(state);
}, 1000),
},
);
```
## Road Map
- [ ] create nicer API, or a helper hook in react land (useTemporal). or vanilla version of the it
- [ ] support history branches rather than clearing the future states
- [ ] track state for multiple stores at once
## Author
Charles Kornoelje ([@\_charkour](https://twitter.com/_charkour))
## Versioning
View the [releases](https://github.com/charkour/zundo/releases) for the change log. This project follows semantic versioning.
## Illustration Credits
Ivo IliΔ ([@theivoson](https://twitter.com/theivoson))