Add collection.select(fields) to Firestore

[mixtly87]

Library	Class	Member	Platforms
Firestore	collection	select	all

Would be useful to support retrieving only specific fields from Firestore documents.

Something like:

fun getCities() = flow {
    firestore.collection("cities")
        .select("name", "population")
        .snapshots.collect { snapshot ->
        val cities = snapshot.documents.map { doc ->
            doc.data<City>()
        }.sortedBy { it.name }
        emit(cities)
    }
}

Idea is to only fetch needed fields and prevent network-transport of potentially heavy documents.

[nbransby]

Is this possible with the android SDK?

[mixtly87]

@nbransby Hm, I'm not sure. After quick inspection it seems that Android SDK doesn't support the select() capability of Firestore SDK.

However I'm not sure if this library uses firestore android SDK under the hood or Firebase support is implemented from scratch (in which case it would not matter if Firebase Android SDK supports select).

[nbransby]

We depend on the android, iOS and js firebase sdks so can only add features they support

[mixtly87]

Ok, I understand.