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OnSnapshot(useFirestoreDoc) is returning result twice. 1. fromCache: false 2. fromCache: true
See original GitHub issueVersion info
React: 16.9.0
Firebase: 7.2.0
ReactFire: 2.0.0-canary.1fce6b9
Other (e.g. Node, browser, operating system) (if applicable):
Issue
When I use useFirestoreDoc, it has useState hook somewhere inside (I am guessing somewhere inside useObservable) and useFirestoreDoc is using onSnapshot method of firebase and returns snapshot result of queried document.
When I tried to log this snapshot, I am getting the result twice:
1. _fromCache: false
2. _fromCache: true
This renders the component 2 times, because useState hook is used inside useObservable.
My Questions
-
Why it is sending 2 results??
-
How can I rectify this 2 renders issue?
-
_fromCache: trueis only expected when user is offline, why it is fetching from cache even when user is online??
Issue Analytics
- State:
- Created 4 years ago
- Comments:8 (4 by maintainers)
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I haven’t had much time to look at this. Hopefully will have more this week. My assumption that this is caused by
useObservablepiping an initial value into the Observable: https://github.com/FirebaseExtended/reactfire/blob/e1daab435f10c629267ff8c2966da878327c941d/reactfire/useObservable/index.ts#L68This is the expected behavior of the Firebase JS SDK, which we use. Feature request is #195