useExtractedObservable

从一个或多个组合式中提取并使用 RxJS Observable，返回一个 ref，并在组件卸载时自动取消订阅。

在可观察对象发生变化时自动取消订阅，并在组件卸载时自动取消订阅。

支持与 watch 的所有重载签名匹配的签名。

用法

import { useExtractedObservable } from '@vueuse/rxjs'
import ObservableSocket from 'observable-socket'
import { computed } from 'vue'
import { makeSocket, useUser } from '../some/lib/func'

// setup()
const user = useUser()
const lastMessage = useExtractedObservable(user, u => ObservableSocket.create(makeSocket(u.id)).down)

如果你想要为可能出错的 Observable 添加自定义错误处理，你可以提供一个可选的 onError 配置。如果没有提供，RxJS 将把提供的 Observable 中的任何错误视为 “未处理的错误”，并且它将在一个新的调用栈中抛出，并报告给 window.onerror (或者如果你恰好在 Node 中，则为 process.on('error'))。

import { useExtractedObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { mapTo, scan, startWith, tap } from 'rxjs/operators'
import { shallowRef } from 'vue'

// setup()
const start = shallowRef(0)

const count = useExtractedObservable(
  start,
  (start) => {
    return interval(1000).pipe(
      mapTo(1),
      startWith(start),
      scan((total, next) => next + total),
      tap((n) => {
        if (n === 10)
          throw new Error('oops')
      })
    )
  },
  {
    onError: (err) => {
      console.log(err.message) // "oops"
    },
  }
)

如果需要，在观察的可观察对象完成时附加特殊行为，你还可以提供一个可选的 onComplete 配置。

import { useExtractedObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { mapTo, scan, startWith, takeWhile } from 'rxjs/operators'
import { shallowRef } from 'vue'

// setup()
const start = shallowRef(0)

const count = useExtractedObservable(
  start,
  (start) => {
    return interval(1000).pipe(
      mapTo(1),
      startWith(start),
      scan((total, next) => next + total),
      takeWhile(num => num < 10)
    )
  },
  {
    onComplete: () => {
      console.log('Done!')
    },
  }
)

如果需要，你还可以将 watch 选项作为最后一个参数传递：

import { useExtractedObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { mapTo, scan, startWith, takeWhile } from 'rxjs/operators'
import { shallowRef } from 'vue'

// setup()
const start = shallowRef<number>()

const count = useExtractedObservable(
  start,
  (start) => {
    return interval(1000).pipe(
      mapTo(1),
      startWith(start),
      scan((total, next) => next + total),
      takeWhile(num => num < 10)
    )
  },
  {},
  {
    immediate: false
  }
)

Options

Option	Type	Description
initialValue	T	Value to use before the Observable emits
onError	(err: any) => void	Error handler for Observable errors
onComplete	() => void	Called when the Observable completes

Return Value

Returns a readonly ShallowRef containing the latest value emitted by the extracted Observable.

Type Declarations

export interface UseExtractedObservableOptions<
  E,
> extends UseObservableOptions<E> {
  onComplete?: () => void
}
export declare function useExtractedObservable<
  T extends MultiWatchSources,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  sources: [...T],
  extractor: WatchExtractedObservableCallback<
    MapSources<T>,
    MapOldSources<T, Immediate>,
    E
  >,
  options?: UseExtractedObservableOptions<E>,
  watchOptions?: WatchOptions<Immediate>,
): Readonly<ShallowRef<E>>
export declare function useExtractedObservable<
  T extends Readonly<MultiWatchSources>,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  sources: T,
  extractor: WatchExtractedObservableCallback<
    MapSources<T>,
    MapOldSources<T, Immediate>,
    E
  >,
  options?: UseExtractedObservableOptions<E>,
  watchOptions?: WatchOptions<Immediate>,
): Readonly<ShallowRef<E>>
export declare function useExtractedObservable<
  T,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  sources: WatchSource<T>,
  extractor: WatchExtractedObservableCallback<
    T,
    Immediate extends true ? T | undefined : T,
    E
  >,
  options?: UseExtractedObservableOptions<E>,
  watchOptions?: WatchOptions<Immediate>,
): Readonly<ShallowRef<E>>
export declare function useExtractedObservable<
  T extends object,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  sources: T,
  extractor: WatchExtractedObservableCallback<
    T,
    Immediate extends true ? T | undefined : T,
    E
  >,
  options?: UseExtractedObservableOptions<E>,
  watchOptions?: WatchOptions<Immediate>,
): Readonly<ShallowRef<E>>