duytruongit / Kotlin-Realm-Extensions

Kotlin extensions for simplifying Realm API.

Description

Simplify your code to its minimum expression with this set of kotlin extensions for Realm. Forget about all boilerplate related with Realm API and performs database operations in one line of code.

Download

Grab via Gradle:

repositories {
    mavenCentral()
}

compile 'com.github.vicpinm:krealmextensions:1.0.2'

Usage

Store entities

All your entities should extend RealmObject.

Before (java)

User user = new User("John");

Realm realm = Realm.getDefaultInstance();
realm.beginTransaction();
realm.copyToRealmOrUpdate(user);  
realm.commitTransaction();
realm.close();

After (Kotlin + extensions)

User("John").save()

Save method creates or updates your entity into database. You can also use create() method, which only create a new entity into database. If a previous one exists with the same primary key, it will throw a exception.

Save list: Before (java)

List<User> users = new ArrayList<User>(...);

Realm realm = Realm.getDefaultInstance();
realm.beginTransaction();
realm.copyToRealmOrUpdate(users);  
realm.commitTransaction();
realm.close();

Save list: After (Kotlin + extensions)

listOf<User>(...).saveAll()

Query entities

All query extensions return detached realm objects, using copyFromRealm() method.

Get first entity: Before (java)

Realm realm = Realm.getDefaultInstance();
Event firstEvent = realm.where(Event.class).findFirst();
firstEvent = realm.copyFromRealm(event);
realm.close();

Get first entity: After (Kotlin + extensions)

val firstEvent = Event().firstItem

You can use lastItem extension too.

Get all entities: Before (java)

Realm realm = Realm.getDefaultInstance();
List<Event> events = realm.where(Event.class).findAll();
events = realm.copyFromRealm(event);
realm.close();

Get all entities: After (Kotlin + extensions)

val events = Event().allItems

Get entities with conditions: Before (java)

Realm realm = Realm.getDefaultInstance();
List<Event> events = realm.where(Event.class).equalTo("id",1).findAll();
events = realm.copyFromRealm(event);
realm.close();

Get entities with conditions: After (Kotlin + extensions)

val events = Event().query { query -> query.equalTo("id",1) }

Delete entities

Delete all: Before (java)

Realm realm = Realm.getDefaultInstance();
List<Event> events = realm.where(Event.class).findAll().deleteAllFromRealm();
events = realm.copyFromRealm(event);
realm.close();

Delete all: After (Kotlin + extensions)

Event().deleteAll()

Delete with condition: Before (java)

Realm realm = Realm.getDefaultInstance();
List<Event> events = realm.where(Event.class).equalTo("id",1).findAll().deleteAllFromRealm();
events = realm.copyFromRealm(event);
realm.close();

Delete with condition: After (Kotlin + extensions)

Event().delete { query -> query.equalTo("id", 1) }

Observe data changes

Before (java)

Realm realm = Realm.getDefaultInstance();
Observable<List<Event>> obs =  realm.where(Event.class).findAllAsync()
.asObservable()
.filter(RealmResults::isLoaded)
.map(realm::copyFromRealm)
.doOnUnsubscribe(() -> realm.close());

After (Kotlin + extensions)

val obs = Event().allItemsAsObservable

Observe query with condition: Before (java)

Realm realm = Realm.getDefaultInstance();
Observable<List<Event>> obs =  realm.where(Event.class).equalTo("id",1).findAllAsync()
.asObservable()
.filter(RealmResults::isLoaded)
.map(realm::copyFromRealm)
.doOnUnsubscribe(() -> realm.close());

Observe query with condition: After (Kotlin + extensions)

val obs = Event().queryAsObservable { query -> query.equalTo("id",1) }