hooks/docs/guide/upgrade.en-US.md

## v2 to v3

Compared with the ahooks v2 version, the changes in the ahooks v3 version mainly include:

- New `useRequest`
- Support SSR
- Special treatment for input and output functions to avoid closure problems
- Hooks of DOM support dynamic target
- Solved the problem in Strict Mode
- Solved the problem in react-refresh (HMR) mode
- Fixed known issues
- Added more Hooks

## Upgrade suggestion

We have released the `ahooks-v2` package, you can install v2 and v3 dependencies at the same time to transition upgrades.

```bash
npm install ahooks-v2 --save
npm install ahooks --save
```

## New useRequest

useRequest has been rewritten:

- Organized the source code through a plug-in pattern, the core code is extremely simple, and can be easily extended for more advanced features.
- Provides step-by-step documentation.
- Fixed the way of exception handling, provides `run` and `runAsync` two trigger functions.
- The `options` parameter supports dynamic changes.
- Deleted `pagination`, `loadMore`, `formatResult` options to avoid the overload of TypeScript, it is more convenient for encapsulating more advanced Hooks based on `useRequest`.

### Detailed changes

- Deleted `UseRequestProvider`, it is recommended to encapsulate advanced Hooks based on `useRequest` instead.
- Removed `pagination` related options, it is recommended to use `usePagination` or `useAntdTable` to achieve paging ability.
- Removed `loadMore` related options, it is recommended to use `useInfiniteScroll` to achieve unlimited loading ability.
- Removed `fetchKey`, that is, deleted concurrent request.
- Removed `formatResult`, `initialData`, and `throwOnError`.
- The request library is no longer integrated by default, and `service` no longer supports string or object.
- Added `runAsync` and `refreshAsync`, the original `run` no longer returns Promise.
- Added error retry ability.
- Added `onBefore` and `onFinally` life cycles.
- Added cache clear ability.
- All options support dynamic changes.
- In debounce/throttle mode, `runAsync` can return current Promise.
- Debounce/throttle mode supports more options.
- Only successful request data will be cached.
- Upgraded `ready` behavior

[How is useRequest compatible with deleted capabilities?](#how-is-userequest-compatible-with-deleted-capabilities)

## Support SSR

ahooks v3 fully supports SSR, and related documents can be found in "[React Hooks & SSR](/guide/blog/ssr)".

## Hooks of DOM support dynamic target

Hooks of DOM support dynamic target, and related documents can be found in "[Hooks of DOM specification](/guide/dom)".

## Avoid closure problems

Inside ahooks, we have made special treatment for the functions input by the user and the functions returned, to avoid the closure problem as much as possible.

**The reference address of all output functions of ahooks will not change.**

```ts
const [state, setState] = React.useState();
```

As we all know, the `setState` reference address returned by `React.useState` will not change.

All functions returned in ahooks have the same characteristics as `setState`, and the reference address will not change.

```ts
const [state, { toggle }] = useToggle();
```

For example, the reference address of `toggle` function returned by `useToggle` is always stable.

**All input functions of ahooks always use the latest one.**

For the received function, ahooks will do a special process to ensure that the function called each time is always the latest.

```ts
const [state, setState] = useState();

useInterval(() => {
  console.log(state);
}, 1000);
```

For example, in the above example, the function called by `useInterval` is always the latest.

Related documents can be found in "[ahooks function specification](/guide/blog/function)".

## Support strict mode

v3 fixed some problems in strict mode. Refer to "[React Hooks & strict mode](/guide/blog/strict)"

## Support react-refresh (HMR) mode

v3 fixed some problems in react-refresh (HMR) mode. Refer to "[React Hooks & react-refresh (HMR)](/guide/blog/hmr)"

## More changes

### New Hooks

- [useRafState](/hooks/use-raf-state)
- [useSetState](/hooks/use-set-state)
- [useAsyncEffect](/hooks/use-async-effect)
- [useDeepCompareEffect](/hooks/use-deep-compare-effect)
- [useIsomorphicLayoutEffect](/hooks/use-isomorphic-layout-effect)
- [useLatest](/hooks/use-latest)
- [usePagination](/hooks/use-pagination)
- [useLongPress](/hooks/use-long-press)
- [useInfiniteScroll](/hooks/use-infinite-scroll)

### Breaking Changes

- useBoolean

  - `toggle` no longer accepts parameters
  - Added `set`

- useToggle

  - `toggle` no longer accepts parameters
  - Added `set`

- useSet

  - Removed `has` method, use `state.has` instead

- useCookieState

  - `setState(null)` is no longer supported to delete cookies, please use `setState(undefined)` or `setState()` instead

- useCountDown

  - Deleted the return value of `setTargetDate`, you can dynamically change `options.targetDate` to achieve the same effect

- useLocalStorageState / useSessionStorageState

  - The second parameter changed from `defaultValue` to `Options`, use `options.defaultValue` instead
  - Added `options.serializer` and `options.deserializer` to support custom sequence method

- useDynamicList

  - `sortForm` was renamed to `sortList`

- useDrag & useDrop

  - API is redesigned and needs to be upgraded according to the new document

- useExternal

  - API has undergone major adjustments, please refer to the documentation
  - No longer supports image type resources
  - The resource becomes globally unique and will not be loaded repeatedly. At the same time, if there are multiple references, the resource will be deleted only after all references are unloaded

- useFullscreen

  - API has been renamed, please refer to the documentation

- useVirtualList

  - API is redesigned and needs to be upgraded according to the new document
  - Added a `data` parameter to the function type `options.itemHeight` parameter

- useInViewport

  - API has been upgraded, please refer to the documentation
  - Added visible ratio ability

- useScroll

  - The return value type is changed from `{ left?: number, top?: number }` to `{ left: number, top: number } | undefined`

- useSize

  - The return value type is changed from `{ width?: number, height?: number }` to `{ width: number, height: number } | undefined`

- useKeyPress

  - All aliases have been modified, please refer to the documentation

- useAntdTable

  - Removed `options.formatResult`
  - More changes are the same as useRequest

- useFusionTable

  - Removed `options.formatResult`
  - More changes are the same as useRequest

- usePersistFn was renamed to useMemoizedFn

- Deprecated the useControlledValue naming left over from 1.0, please use useControllableValue instead

### Optimization

- useUrlState

  - Supported React Router v6

- useControllableValue

  - Optimized logic to avoid unnecessary re-render

- More other optimizations

## FAQ

### How is useRequest compatible with deleted capabilities?

The new version of useRequest only provides the underlying capabilities of Promise management, and more advanced capabilities can be supported by encapsulating advanced Hooks based on useRequest.

1. `options.formatResult` is deleted, and the service is expected to return the data in the final format. for example:

```ts
const { data } = useRequest(async () => {
  const result = await getData();
  return result.data;
});
```

2. The original concurrent mode of `options.fetchKey` is deleted. It is expected that each request action and UI will be encapsulated as a component instead of placing all requests in the parent.

3. `options.initialData` is deleted, you can do this

```ts
const { data = initialData } = useRequest(getData);
```

4. The request library is no longer integrated by default, and `service` no longer supports string or object. It is expected to be supported by encapsulating advanced Hooks based on useReqeust. for example:

```ts
const useCustomHooks = (pathname, options) => {
  return useRequest(() => {
    return axios(pathname);
  }, options);
};
```