Bdtjtk

I´ve a role based data model on Firestore according to googles suggestion here: https://firebase.google.com/docs/firestore/solutions/role-based-access

Security rules are set up correctly and work fine. But now I´ve the problem on how to query for the roles.

This is my data model (one sample document):

id: "1234-5678-91234",

roles:

    userId_1:"owner",

    userId_2:"editor

title: "This is a sample document"

And this is my Firestore Query in Flutter which gets all documents for a specific user by its ID if the user has assigned the role "owner" for the document:

return firestore

.collection(path)

.where("roles.${user.firebaseUserId}", isEqualTo: "owner")

.snapshots().map((snapshot) {

  return snapshot.documents.map((catalog) {

    return SomeDocumentObject(...);

  }).toList();

});

My problem now is, that I need some kind of "OR" clause - which does not exist as far as I know. The query above only retrieves documents for users with role "owner" but I need a query that also retrieves the document if the userId is associated with the role "editor".

I´ve tried "arrayContains:" which also doesn´t seem to work (cause it´s a map).

I´ve read about solutions with two independent queries which doesn´t sound like a good solution due to a lot of overhead.

Maybe someone of you have a hint for me? :)

Thanks & best,
Michael

Firestore doesn't currently have any logical OR operations. You'll have to perform two queries, one for each condition, and merge the results of both queries in the client app.

This is the final solution using RxDart, Observables and .combineLatest() - maybe it helps someone out there:

@override

Stream<List<Catalog>> catalogs(User user) {



    // Retrieve all catalogs where user is owner

    Observable<QuerySnapshot> ownerCatalogs = Observable(firestore

        .collection(path)

        .where("roles.${user.firebaseUserId}", isEqualTo: "owner")

        .snapshots());



    // Retrieve all catalogs where user is editor

    Observable<QuerySnapshot> editorCatalogs = Observable(firestore

        .collection(path)

        .where("roles.${user.firebaseUserId}", isEqualTo: "editor")

        .snapshots());



    // Convert merged stream to list of catalogs

    return Observable.combineLatest([ownerCatalogs, editorCatalogs],

        (List<QuerySnapshot> snapshotList) {

      List<Catalog> catalogs = ;



      snapshotList.forEach((snapshot) {

        snapshot.documents.forEach((DocumentSnapshot catalog) {

          catalogs.add(Catalog(

            id: catalog.documentID,

            title: catalog.data['title'],

            roles: catalog.data['roles'],

          ));

        });

      });

      return catalogs;

    }).asBroadcastStream();

  }