Refresh observable on dependency change

[tom-sherman]

Opening mainly to see if this is a good idea or now! Happy to clean up the API/examples if it is.

Basically I needed a way to restart the observable on dependency changes. I've added another argument to userObservable which allows you to set the dependencies of useEffect. Let me know what you think!

import React from 'react' import ReactDOM from 'react-dom' import { useObservable } from 'rxjs-hooks' import { from } from 'rxjs' import { map, take } from 'rxjs/operators' function App(props: { foo: number }) { const value = useObservable(() => from([1, 2, 3, 4]).pipe( map(val => val + props.foo) ), 200, [props.foo]) return ( // render four times // 2, 4, 5, 6 <h1>{value}</h1> ) } ReactDOM.render(<App foo={1} />, document.querySelector('#app')) ReactDOM.render(<App foo={2} />, document.querySelector('#app'))

[Brooooooklyn]

The behavior in you implmentation is switchMap when every deps changed. That may not expected behavior in some scenarios.
If you want refresh aka switchMap your Observable, you could write codes like that:

const value = useObservable((deps$) => deps$.pipe( switchMap(foo => from([1, 2, 3]).pipe( map(val => val + foo) )), ) , 200, [props.foo])

And also, you can choose exhaustMap or concatMap or flatMap it