[React Native/ Expo only] Add offline support 👀

[nandorojo]

This issue only applies to mobile apps built with Expo. Firestore persistence works fine with this library with normal React.

Data should cache to AsyncStorage something like redux persist, and any mutations should somehow bubble up to happen later...🙃

If anyone stumbles upon this, would love help.

[nandorojo]

Relevant discussion from SWR: vercel/swr#16

[puchesjr]

Wouldn't this be possible by just using the Firestore option of enablePersistence=true?

[nandorojo]

Yeah!

The only problem is that Firestore doesn't have persistence support for React Native / @expo, which I use primarily. But if you don't use React Native, then you're fine using the normal Firestore persistence.

There is a work-around for React Native here: https://gist.github.com/zwily/e9e97e0f9f523a72c24c7df01d889482 and https://github.com/firebase/firebase-js-sdk/blob/3c8f85d0185e3305f0ba7790d46eebb8e9e78e62/packages/firestore/test/util/node_persistence.ts (though this one might be slow on RN)

For more, see the original Firestore issue: firebase/firebase-js-sdk#436

[puchesjr]

Ah yes - I was thinking of this from a web perspective. But, you could use this https://rnfirebase.io/reference/firestore/settings for react-native :).

[nandorojo]

Good call! Unfortunately that library doesn’t support Expo without detaching, so it will only work for Bare expo projects. A pure-JS solution for managed Expo apps specifically is what I’m hoping to achieve

[nandorojo]

Solved this with https://github.com/nandorojo/expo-firestore-offline-persistence. Turned it into its own package.