Flutter Cloud Firestore only getting most recent data when debugging

1
votes

I've run into a really weird error, and I can't wrap my head around it.

I do a query like this:

var currentSnapshot = await Firestore.instance
        .collection('station1')
        .orderBy("servertime", descending: true)
        .limit(1)
        .snapshots()
        .first;

To get the most recent document in some collection based on the server-timestamp that I have on each document. For some reason, this results in retrieving the newest documents only when debugging line by line. This could indicate that it has something to do with timing, as I'm introducing a lot more time when stepping through things.

The code is called every X seconds through the use of this:

Timer.periodic(Duration(seconds: 120), (Timer t) => updateMeasurements());

When I run without stepping through it with the debugger, it seems to only retrieve the correct value the first time, and when there are new documents added in the collection, it does not retrieve these.

Am I doing any obvious mistakes? Any ideas on what to try? All help appreciated!

1
firebaseflutterdartgoogle-cloud-firestore

1 Answers

4
votes

It seems like this was related to having persistence activated for Firestore in Flutter. It might be related to me doing first for the stream.

I disabled persistence as follows:

Firestore.instance.settings(persistenceEnabled: false);

And now it consistently retrieves the most recent value.