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自动生成选择器

¥Auto Generating Selectors

我们建议在使用存储中的属性或操作时使用选择器。你可以像这样从存储中访问值:

¥We recommend using selectors when using either the properties or actions from the store. You can access values from the store like so:

typescript
const bears = useBearStore((state) => state.bears)

但是,编写这些可能很繁琐。如果你的情况如此,你可以自动生成选择器。

¥However, writing these could be tedious. If that is the case for you, you can auto-generate your selectors.

创建以下函数:createSelectors

¥Create the following function: createSelectors

typescript
import { StoreApi, UseBoundStore } from 'zustand'

type WithSelectors<S> = S extends { getState: () => infer T }
  ? S & { use: { [K in keyof T]: () => T[K] } }
  : never

const createSelectors = <S extends UseBoundStore<StoreApi<object>>>(
  _store: S,
) => {
  let store = _store as WithSelectors<typeof _store>
  store.use = {}
  for (let k of Object.keys(store.getState())) {
    ;(store.use as any)[k] = () => store((s) => s[k as keyof typeof s])
  }

  return store
}

如果你有这样的存储:

¥If you have a store like this:

typescript
interface BearState {
  bears: number
  increase: (by: number) => void
  increment: () => void
}

const useBearStoreBase = create<BearState>()((set) => ({
  bears: 0,
  increase: (by) => set((state) => ({ bears: state.bears + by })),
  increment: () => set((state) => ({ bears: state.bears + 1 })),
}))

将该函数应用于你的存储:

¥Apply that function to your store:

typescript
const useBearStore = createSelectors(useBearStoreBase)

现在选择器是自动生成的,你可以直接访问它们:

¥Now the selectors are auto generated and you can access them directly:

typescript
// get the property
const bears = useBearStore.use.bears()

// get the action
const increment = useBearStore.use.increment()

原始存储

¥Vanilla Store

如果你使用的是 vanilla store,请使用以下 createSelectors 函数:

¥If you are using a vanilla store, use the following createSelectors function:

typescript
import { StoreApi, useStore } from 'zustand'

type WithSelectors<S> = S extends { getState: () => infer T }
  ? S & { use: { [K in keyof T]: () => T[K] } }
  : never

const createSelectors = <S extends StoreApi<object>>(_store: S) => {
  const store = _store as WithSelectors<typeof _store>
  store.use = {}
  for (const k of Object.keys(store.getState())) {
    ;(store.use as any)[k] = () =>
      useStore(_store, (s) => s[k as keyof typeof s])
  }

  return store
}

用法与 React 存储相同。如果你有这样的存储:

¥The usage is the same as a React store. If you have a store like this:

typescript
import { createStore } from 'zustand'

interface BearState {
  bears: number
  increase: (by: number) => void
  increment: () => void
}

const store = createStore<BearState>((set) => ({
  bears: 0,
  increase: (by) => set((state) => ({ bears: state.bears + by })),
  increment: () => set((state) => ({ bears: state.bears + 1 })),
}))

将该函数应用于你的存储:

¥Apply that function to your store:

typescript
const useBearStore = createSelectors(store)

现在选择器是自动生成的,你可以直接访问它们:

¥Now the selectors are auto generated and you can access them directly:

typescript
// get the property
const bears = useBearStore.use.bears()

// get the action
const increment = useBearStore.use.increment()

直播演示

¥Live Demo

有关此示例,请参阅 代码 Sandbox

¥For a working example of this, see the Code Sandbox.

第三方库

¥Third-party Libraries

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