Callback for Realm file events: Created/deleted/migrated

Goal

My goal is to run initialData transaction asynchronously. However, given my Android application use case, I don’t think the new Realm.getInstanceAsync is the best fit.

Expected Results

Get Realm instance synchronously, but execute initialData transaction asynchronously.

Actual Results

With Realm.getInstanceAsync, introduced in Realm 3.2.0, a Realm object is not returned synchronously.

That has implications when you are using dependency injection for the Realm instance, as it would make the workflow much more complex than it needs to be (should I not be using it at all?).

Right now, to initialize data, I’m simply making use of SharedPreferences and running a transaction asynchronously.

Version of Realm

Realm version: 3.2.0

[cmelchior]

Hi @jpmcosta No, feature requests should go here 😃

It is an interesting use case. By doing an async transaction it also means that you are OK with the Realm instance not being “fully” initialized?

The natural option would be to add something like RealmConfiguration.initialDataAsync() but calling something “initial*” kinda implies that it is setup when the Realm is opened, so that doesn’t feel right to me.

If I remember correctly we have heard other use cases for doing other things when a Realm is created, like resetting SharedPrefs or similar (need to dig those up). So I’m thinking that perhaps we should expose a lifecylecallback whenever the Realm is created/reset, and then you could do whatever. Something like:

RealmConfiguration config = new RealmConfiguration.Builder()
  .realmHandler(new RealmCreatedCallback() {
      @override
      public void onRealmCreated(RealmConfiguration config) {
         // Callback when the Realm file is created the first time. Called after inititialData/assetFile has been executed
      }
  })
 .build();

Naming and scope is up for debate of course:

Name:

• .realmHandler(...)
• .onRealmCreated(...)
• .lifecycleHandler(...)
• .realmFileHandler(...)
• .eventHandler(...)
• Other ideas?

Possible scope:

• onRealmCreated
• onRealmMigrated
• onRealmDeleted
• others?

Would something like that work for you?

[jpmcosta]

Would something like that work for you?

@cmelchior Yes, that would be perfect! I also envisioned something like initialDataAsync, but the lifecyclecallback should work much better.

Edit: I didn’t read the comma! Thanks for your answer.