Deleted record visible until "hard" refresh - Ember Data - Firebase

[zoltan-nz]

Deleted record visible until "hard" refresh - Ember Data - Firebase

[dominiks]

Hi Zoltan, I tried modifying the adapter's behaviour with shouldBackgroundReloadAll and shouldReloadAll but that didn't help. I agree that I could probably solve the problem by adding real time communication via websockets between the ember store and the server but that is probably complete overkill if one does not need it to be realtime.

But it turns out other people are having the same issue: emberjs/data#4564
The findAll() method ignores items that are missing in the server response but still present in the local cache and it looks like this is not going to change. This is the expected and documented behaviour of findAll():

findAll asks the adapter's findAll method to find the records for the given type, and returns a promise which will resolve with all records of this type present in the store, even if the adapter only returns a subset of them.

So in the end I found 2 workarounds for this:

1. Clear the local cache of library objects if you're going to load them all

model() {
  this.store.unloadAll("library");
  return this.store.findAll("library");
}

2. Use query() which doesn't do this. If you want to load all objects pass an empty hash as the parameter or parameters your server will ignore:

model() {
  return this.store.query("library", {});
}

I feel that with these workarounds the issue is acceptable as one might usually use query() on large datasets instead of findAll() anyways to have pagination, filtering and such.

Thanks four your quick response and helping me find a workable solution. 👍

[zoltan-nz]

@dominiks Hey Dominiks, thank you.

Great findings and you are right. I noticed the same when I started to play with Firebase. As I see Firebase realtime sync your data when you create a new item, however they don't sync "delete", so it is not realtime... As I see here, in Firebase doc, the official Firebase library supports this option, maybe this is missing from the Emberfire package.

If you built your own server backend, you have to manually setup realtime "websocket" communication.

You can check out this hooks also in Ember Adapter:
https://www.emberjs.com/api/ember-data/3.7/classes/DS.Adapter/methods/shouldReloadAll?anchor=shouldBackgroundReloadAll

You can force your Adapter to reload all the records from the server. So it is always try to find out what is the latest state of your database. Maybe this is only what you need.

Hope this could help, don't hesitate to share your findings and let me know which solution worked. :)