user3806331 user3806331 - 3 months ago 38
Android Question

Realm Proper way of Copy Object In Transaction with RxJava

Currently, when copying a value to realm, i do the following:

public void addToRealm(Home item, RealmChangeListener<E> listener) {

realm.executeTransaction((Realm realm1) ->

And then i can access the newly added object inside the listener. What is the proper RxJava way of accomplishing the same? The observable must return
, which is the realmCopy not the original object. Can any1 please provide a sample?

Managed to get it working by doing this, altought im not sure it is the best approach... What is the recommended approach?

return Observable.just(homeItem)
.map { (HomeItem homeItem) ->
return AnotherHomeItem(, homeItem.yyy)
.flatMap { (AnotherHomeItem anotherItem) ->
val newItem = realm.copyToRealm(anotherItem).asObservable< AnotherHomeItem >()
return newItem
.filter {
return it.isLoaded


You should write to the Realm on a background thread, and observe with a different subscription on the UI thread.

I wrote this documentation example to show how that works.

You persist with one subscription on the background thread:

public Subscription downloadObjectsFromNetwork() {
    return objectApi.getObjects()
        .subscribe(response -> {
            try(Realm realmInstance = Realm.getDefaultInstance()) {
                realmInstance.executeTransaction(realm -> realm.insertOrUpdate(response.objects));

And you read with asObservable() on the UI thread:

public Subscription readFromRealm() {
    return realm.where(SomeObject.class)
         .subscribe(objects -> adapter.updateData(objects));