from / fromEvent
RxJS 的 from() 和 fromEvent() 的包装器,使它们能够接受 ref。 Available in the @vueuse/rxjs add-on.
用法
ts
import { from, fromEvent, toObserver, useSubscription } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { map, mapTo, takeUntil, withLatestFrom } from 'rxjs/operators'
import { shallowRef, useTemplateRef } from 'vue'
const count = shallowRef(0)
const button = useTemplateRef('buttonRef')
useSubscription(
interval(1000)
.pipe(
mapTo(1),
takeUntil(fromEvent(button, 'click')),
withLatestFrom(from(count, {
immediate: true,
deep: false,
})),
map(([curr, total]) => curr + total),
)
.subscribe(toObserver(count)), // 与 ).subscribe(val => (count.value = val)) 相同
)js
import { from, fromEvent, toObserver, useSubscription } from '@vueuse/rxjs'
import { interval } from 'rxjs'
import { map, mapTo, takeUntil, withLatestFrom } from 'rxjs/operators'
import { shallowRef, useTemplateRef } from 'vue'
const count = shallowRef(0)
const button = useTemplateRef('buttonRef')
useSubscription(
interval(1000)
.pipe(
mapTo(1),
takeUntil(fromEvent(button, 'click')),
withLatestFrom(
from(count, {
immediate: true,
deep: false,
}),
),
map(([curr, total]) => curr + total),
)
.subscribe(toObserver(count)),
)from
The from function can accept either a standard RxJS ObservableInput or a Vue ref. When passed a ref, it creates an Observable that emits whenever the ref's value changes.
Watch Options
When using from with a ref, you can pass Vue's WatchOptions:
| Option | Type | Description |
|---|---|---|
immediate | boolean | Emit the current value immediately |
deep | boolean | Deeply watch nested objects |
flush | 'pre' | 'post' | 'sync' | Timing of the callback flush |
fromEvent
The fromEvent function extends RxJS's fromEvent to accept a ref to an element. When the ref's value changes (e.g., after the component mounts), it automatically subscribes to the new element.
ts
import { fromEvent, useSubscription } from '@vueuse/rxjs'
import { useTemplateRef } from 'vue'
const button = useTemplateRef('buttonRef')
// Will automatically subscribe when the button element becomes available
useSubscription(
fromEvent(button, 'click').subscribe(() => {
console.log('clicked!')
})
)类型声明
ts
export declare function from<T>(
value: ObservableInput<T> | Ref<T>,
watchOptions?: WatchOptions,
): Observable<T>
export declare function fromEvent<T extends HTMLElement | null>(
value: MaybeRef<T>,
event: string,
): Observable<Event>