useObservable

Use an RxJS Observable, return a ref, and automatically unsubscribe from it when the component is unmounted.

Available in the @vueuse/rxjs add-on.

Usage

import { ref } from 'vue'
import { useObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { mapTo, scan, startWith } from 'rxjs/operators'

// setup()
const count = useObservable(
  interval(1000).pipe(
    mapTo(1),
    startWith(0),
    scan((total, next) => next + total),
  ),
)

import { ref } from 'vue'
import { useObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { mapTo, scan, startWith } from 'rxjs/operators'

// setup()
const count = useObservable(
  interval(1000).pipe(
    mapTo(1),
    startWith(0),
    scan((total, next) => next + total),
  ),
)

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).

import { ref } from 'vue'
import { useObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { map } from 'rxjs/operators'

// setup()
const count = useObservable(
  interval(1000).pipe(
    map((n) => {
      if (n === 10)
        throw new Error('oops')

      return n + n
    }),
  ),
  {
    onError: (err) => {
      console.log(err.message) // "oops"
    },
  },
)

import { ref } from 'vue'
import { useObservable } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { map } from 'rxjs/operators'

// setup()
const count = useObservable(
  interval(1000).pipe(
    map((n) => {
      if (n === 10)
        throw new Error('oops')

      return n + n
    }),
  ),
  {
    onError: (err) => {
      console.log(err.message) // "oops"
    },
  },
)

Type Declarations

export interface UseObservableOptions<I> {
  onError?: (err: any) => void
  /**
   * The value that should be set if the observable has not emitted.
   */
  initialValue?: I | undefined
}
export declare function useObservable<H, I = undefined>(
  observable: Observable<H>,
  options?: UseObservableOptions<I | undefined>
): Readonly<Ref<H | I>>

export interface UseObservableOptions<I> {
  onError?: (err: any) => void
  /**
   * The value that should be set if the observable has not emitted.
   */
  initialValue?: I | undefined
}
export declare function useObservable<H, I = undefined>(
  observable: Observable<H>,
  options?: UseObservableOptions<I | undefined>
): Readonly<Ref<H | I>>