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watchExtractedObservable

Category
Export Size
Package
@vueuse/rxjs
Last Changed
2 months ago

Watch the values of an RxJS Observable as extracted from one or more composables.

Automatically unsubscribe on observable change, and automatically unsubscribe from it when the component is unmounted.

Supports all overloads of watch. Available in the @vueuse/rxjs add-on.

Usage

ts
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref<HTMLAudioElement>()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
)
js
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
)

If you want to add custom error handling to an Observable that might error, you can supply an optional onError configuration. Without this, RxJS will treat any error in the supplied Observable as an "unhandled error" and it will be thrown in a new call stack and reported to window.onerror (or process.on('error') if you happen to be in Node).

You can also supply an optional onComplete configuration if you need to attach special behavior when the watched observable completes.

ts
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref<HTMLAudioElement>()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
  {
    onError: (err: unknown) => {
      console.error(err)
    },
    onComplete: () => {
      state.progress = 100 // or 0, or whatever
    },
  },
)
js
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
  {
    onError: (err) => {
      console.error(err)
    },
    onComplete: () => {
      state.progress = 100 // or 0, or whatever
    },
  },
)

If you want, you can also pass watch options as the last argument:

ts
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref<HTMLAudioElement>()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
  {
    onError: (err: unknown) => {
      console.error(err)
    },
  },
  {
    immediate: true,
  },
)
js
import { computed, ref } from 'vue'
import { watchExtractedObservable } from '@vueuse/rxjs'
import { AudioPlayer } from '../my/libs/AudioPlayer'
// setup()
const audio = ref()
const player = computed(() => (audio.value ? new AudioPlayer(audio) : null))
const state = reactive({
  progress: 0,
})
watchExtractedObservable(
  player,
  (p) => p.progress$,
  (percentage) => {
    state.progress = percentage * 100
  },
  {
    onError: (err) => {
      console.error(err)
    },
  },
  {
    immediate: true,
  },
)

Type Declarations

Show Type Declarations
typescript
export type OnCleanup = (cleanupFn: () => void) => void
export type WatchExtractedObservableCallback<
  Value,
  OldValue,
  ObservableElement,
> = (
  value: NonNullable<Value>,
  oldValue: OldValue,
  onCleanup: OnCleanup,
) => Observable<ObservableElement>
export interface WatchExtractedObservableOptions {
  onError?: (err: unknown) => void
  onComplete?: () => void
}
export declare function watchExtractedObservable<
  T extends MultiWatchSources,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  sources: [...T],
  extractor: WatchExtractedObservableCallback<
    MapSources<T>,
    MapOldSources<T, Immediate>,
    E
  >,
  callback: (snapshot: E) => void,
  subscriptionOptions?: WatchExtractedObservableOptions,
  watchOptions?: WatchOptions<Immediate>,
): WatchStopHandle
export declare function watchExtractedObservable<
  T extends Readonly<MultiWatchSources>,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  source: T,
  extractor: WatchExtractedObservableCallback<
    MapSources<T>,
    MapOldSources<T, Immediate>,
    E
  >,
  callback: (snapshot: E) => void,
  subscriptionOptions?: WatchExtractedObservableOptions,
  watchOptions?: WatchOptions<Immediate>,
): WatchStopHandle
export declare function watchExtractedObservable<
  T,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  source: WatchSource<T>,
  extractor: WatchExtractedObservableCallback<
    T,
    Immediate extends true ? T | undefined : T,
    E
  >,
  callback: (snapshot: E) => void,
  subscriptionOptions?: WatchExtractedObservableOptions,
  watchOptions?: WatchOptions<Immediate>,
): WatchStopHandle
export declare function watchExtractedObservable<
  T extends object,
  E,
  Immediate extends Readonly<boolean> = false,
>(
  source: T,
  extractor: WatchExtractedObservableCallback<
    T,
    Immediate extends true ? T | undefined : T,
    E
  >,
  callback: (snapshot: E) => void,
  subscriptionOptions?: WatchExtractedObservableOptions,
  watchOptions?: WatchOptions<Immediate>,
): WatchStopHandle

Source

SourceDocs

Contributors

Anthony Fu
Voltra

Changelog

v10.5.0 on 10/7/2023
23b8c - feat(rxjs): add useExtractedObservable and watchExtractedObservable (#3453)

Released under the MIT License.