FR: Query in operator

[nitrag]

It would be really really nice if we could query this in this SDK. Currently I'm having to store room references in my /users/ Documents

Firestore Data Model for Chat app:

/users/
/users/{userId}/
/users/{userId}/rooms    (this is a DocumentReference Array of rooms)
/users/{userId}/first_name
/users/{userId}/last_name
/users/{userId}/last_active

/rooms/
/rooms/{roomId}/
/rooms/{roomId}/created
/rooms/{roomId}/last_updated
/rooms/{roomId}/users    (this is an String Array of userIds)
/rooms/{roomId}/messages/...

Server-side Rules:
allow read, write: if request.auth.uid in resource.data.users;

Proposed:
roomsRef.where("users", "in", currentUserId)

[wilhuff]

Thanks for writing in.

This is something we're looking at doing. Unfortunately I can't promise when it's going to happen, nor can I really promise if the design we land on will necessarily exactly match what you're asking for.

This specific use case (array of group members) is a specific requirement for adding this.

[wilhuff]

While we're still very interested in this feature, there's little value in tracking this separately for just iOS. The canonical issue for this is firebase/firebase-js-sdk#321. I'll close this one as a duplicate.

[rockwotj]

@wilhuff this is array-contains no?

https://firebase.googleblog.com/2018/08/better-arrays-in-cloud-firestore.html

[mikelehen]

@wilhuff is OOO this week, but I think you're right @rockwotj. array-contains should solve @nitrag's use case!

[nitrag]

I had been using this, do I need the get() if the match is already for the same level object?

service cloud.firestore {
  match /databases/{database}/documents {
    match /rooms/{roomId} {
      allow read, write: if request.auth.uid in get(/databases/$(database)/documents/rooms/$(roomId)).data.users;
      allow create: if request.auth != null;
    }
  }
}

[rockwotj]

You can't use {roomId} for queries in rules because we don't know what document IDs that will be returned at the time of rules evaluation.

For queries we populate the resource property with the minimal document guaranteed to be returned by all query results.

You want this rule:

allow read, write: if request.auth.uid in resource.data.users