cmelchior

// BAD: Store a global managed object
MyApp.GLOBAL_OBJECT = realm.objects(Person::class).first()

// BETTER: Copy data out into an unmanaged object
val person = realm.objects(Person::class).first()
MyApp.GLOBAL_OBJECT = Person(person.name)

cmelchior

// A write can now happen between two queries
val results1: RealmResults<Person> = realm.objects(Person::class)
val results2: RealmResults<Person> = realm.objects(Person::class)

// Resulting in subsequent queries not returning the same result
results1.version() != results2.version()
results1.size != results2.size

cmelchior

val jane = getJane()
CoroutineScope(Dispatchers.Main).launch {

   // Run mapping/transform logic in the background
   val flow: Flow<String> = jane.observe()
       .filter { it.name.startsWith("Jane") }
       .flowOn(Dispatchers.Unconfined)

   // Before collecting on the UI thread
   flow.collect {

cmelchior

val jane = getJane()
CoroutineScope(Dispatchers.Main).launch {
   // Updates are observed using Kotlin Flow
   val flow: Flow<Person> = jane.observe()
   flow.collect {
       // Listen to changes to the object
       println(it.name)
   }
}

cmelchior

CoroutineScope(Dispatchers.Main).launch {
   // Create initial object   
   val jane = realm.write {
       copyToRealm(Person("Jane"))
   }
  
   realm.write {
       // Find latest version and update it
       // Note, this always involves a null-check
       // as another thread might have deleted the

cmelchior

CoroutineScope(Dispatchers.Main).launch {

   // Write automatically happens on a background dispatcher
   val jane = realm.write {
       val unmanaged = Person("Jane")
       // Add unmanaged objects
       copyToRealm(unmanaged)
   }

   // Objects returned from writes are automatically frozen

cmelchior

val jane = realm.writeBlocking { 
   val unmanaged = Person("Jane")
   copyToRealm(unmanaged)
}

cmelchior

// Close Realm to free native resources
realm.close()

cmelchior

// Global App variable
class MyApp: Application() {
   companion object {
       private val config = RealmConfiguration(schema = setOf(Person::class))
       public val REALM = Realm(config)
   }
}

// Using dependency injection
val koinModule = module {

cmelchior

/**
 * Class connecting the Realm lifecycle to that of LiveData objects.
 * Realm will remain open for as long as any LiveData objects are being observed.
 */
abstract class LiveRealmData<T: RealmModel>(val config: RealmConfiguration) : LiveData<RealmResults<T>>() {

    private val listener = RealmChangeListener<RealmResults<T>> { results -> value = results }
    private lateinit var realm: Realm
    private var results: RealmResults<T>? = null