Realm Kotlin SDK/io.realm.kotlin.notifications/ObjectChange

ObjectChange

interface ObjectChange<O : BaseRealmObject> : SingleQueryChange<O>

This sealed interface describe the possible changes that can be observed to a Realm Object.

The specific states are represented by the specific subclasses InitialObject, UpdatedObject and DeletedObject.

Changes can thus be consumed in a number of ways:

// Variant 1: Switch on the sealed interface
realm.filter<Person>().first().asFlow()
  .collect { objectChange: ObjectChange<Person> ->
      when(objectChange) {
         is InitialObject -> initPersonUI(objectChange.obj)
         is UpdatedObject -> updatePersonUi(objectChange.obj, objectChange.changedFields)
         is DeletedObject -> removePersonUi()
      }
  }


// Variant 2: Just pass on the object
realm.filter<Person>().first().asFlow()
  .collect { objectChange: ObjectChange<Person> ->
      handleChange(objectChange.obj)
  }

For state of update changes, a list with the updated field names from the previous version is provided.

Properties

obj

abstract override val obj: O?

Returns the newest state of object being observed. null is returned if the object has been deleted.

Inheritors

InitialObject

UpdatedObject

DeletedObject