rxjs-firestore.js

gistfile1.txt

import { Observable, interval, combineAll, combineLatest } from 'rxjs'
import { zip, startWith, timeInterval } from 'rxjs/operators'
import { useEffect, useState } from 'react'

import RNFirebase from '@react-native-firebase/app'

export const docData = doc => {
  const data = doc.data()
  const idKey = data && data.id ? 'firebaseId' : 'id'

  return {
    ...data,
    [idKey]: doc.id, // if original data contains an id..
  }
}

export const ObservableFromRef = ref => {
  return new Observable(subscriber => {
    const unsubscribe = ref.onSnapshot(snapshot => subscriber.next(snapshot))
    return () => unsubscribe()
  })
}

export const ObservableFromAuthState = auth => {
  return new Observable(subscriber => {
    const unsubscribe = auth.onAuthStateChanged(user => subscriber.next(user))
    return () => unsubscribe()
  })
}

export const updateObservableEveryXSeconds = (observable, seconds) => {
  return combineLatest(
    observable,
    interval(seconds * 1000).pipe(
      startWith(-1),
      timeInterval()
    ),
    (observable, interval) => {
      return observable
    }
  )
}

export const useStream = (stream, initialValue = null) => {
  const [current, setCurrent] = useState(initialValue)

  useEffect(() => {
    const sub = stream.subscribe(setCurrent)
    return () => sub.unsubscribe()
  }, [])

  return current
}