realm-js: addListener notification is empty (documentation only)

When using addListener(objects, changes) on React Native iOS it always returns empty on the first notification and the second notification returns what should have been in the first one.

I found in results-tests.js below that first notification is empty.

Is this by design or am I doing something wrong here? 😀

        realm.objects('TestObject').addListener((testObjects, changes) => {
            // TODO: First notification is empty, so perform these
            // assertions on the second call. However, there is a race condition
            // in React Native, so find a way to do this in a robust way.
            //TestCase.assertEqual(testObjects.length, 4);
            //TestCase.assertEqual(changes.insertions.length, 1);
            resolve();
        });

About this issue

Original URL
State: closed
Created 7 years ago
Reactions: 10
Comments: 27 (5 by maintainers)

Most upvoted comments

@sheshavpd This was a critical issue for me as well, and for now I got it working by doing realm.write(() => {}) (basically a second empty write) after each write. Far from ideal and may not be feasible in your context, but it’s been working well for me in the meantime.

lamflam on Jul 27, 2017

Realm: 1.12.0 RN: 0.47 Platform: iOS 11 BUT only in simulator - on iPhone SE no problem

kosiakMD on Sep 27, 2017

➤ Stoney Burks commented:

We discussed in team meeting that this issue specifically will be handled through documentation. We will, however, create a new feature/enhancement ticket to address long-term solutions.

sync-by-unito[bot] on Jul 4, 2022

Also having this issue in React Native with Realm 1.3.1. After banging my head for a few hours trying to figure out what I was doing wrong I finally realized that these notifications are just always one realm.write() behind. I eventually just added and additional realm.write(() => {}) call which makes it trigger the notification I need right away. Definitely seems to work as a workaround, but looking forward to having a real fix for this.

lamflam on Jun 24, 2017