REALM.IO NOSQL FOR MOBILE

Transcription

1 REALM.IO NOSQL FOR MOBILE

2 Mitchell Tilbrook Mobile Seatfrog Android, ios, Xamarin Recording & Editing for 7+ meet-ups ANZCoders: ANZCoders Android Sydney:

3 WHY?

4 1. Not always FAST 2. Threading is hard 3. Writes can block reads 4. Stringly typed schema 5. Object Mapping 6. Migrations

5

6 DATA MODELS

7 ANDROID MODELS public class Person extends RealmObject { private String name; private int age; // Getters and Setters OR

8 ANDROID INTERFACE public class Person implements RealmModel { private String name; private int age; // Getters and Setters // with RealmObject person.isvalid(); // With RealmModel RealmObject.isValid(user);

9 PROPERTY ATTRIBUTES

10 ANDROID PRIMARY KEY public class Person extends RealmObject private int id; private String name; private Int age; // Getters and Setters

11 REQUIRED public class Person extends RealmObject private String private Int age; // Getters and Setters

12 INDEXING public class Person extends RealmObject private String name; private int age; // Getters and Setters

13 DON'T PERSIST PROPERTIES public class User extends RealmObject { private String private String sessiontoken; // Getters and Setters

14 CUSTOM MODEL LOGIC public class Person extends RealmObject { private String name; private int age; public String getname() { return name.touppercase(); public String getnameandage() { return name + " is " + age + " old"; public void setname(string newname) { name = newname.touppercase();

15 QUERYING // Gets All the Users RealmQuery<Person> query = realm.where(person.class);

16 QUERYING // Gets All the Users RealmQuery<Person> query = realm.where(person.class); // Add query conditions: query.equalto("name", "John"); query.or().equalto("name", "Peter"); // Execute the query: RealmResults<Person> result1 = query.findall(); // Or alternatively do the same all at once (the "Fluent interface"): RealmResults<Person> result2 = realm.where(person.class).equalto("name", "John").or().equalTo("name", "Peter").findAll();

17 MANY-TO-ONE public class Person extends RealmObject { //... private Dog dog; // Getters and Setters

18 MANY-TO-MANY public class Person extends RealmObject { //... private RealmList<Dog> dogs; // Getters and Setters

19 RECURSIVE RELATIONSHIPS public class Person extends RealmObject { public String name; public RealmList<Person> friends; // Other fields public class Person extends RealmObject { public String name; public Person father; // Other fields

20 LINKED QUERIES public class Person extends RealmObject { private String id; private String name; private RealmList<Dog> dogs; // getters and setters public class Dog extends RealmObject { private String id; private String name; private String color; // getters and setters

21 LINKED QUERIES

22 LINKED QUERIES RealmResults<Person> persons = realm.where(person.class).equalto("dogs.color", "Brown").findAll();

23 QUERYING IS LAZY RealmResults<Person> result = realm.where(person.class).findall();

24 READING LAZY DATA Person person = results.get(1); String name = person.getname();

25 ASYNC QUERYING private RealmChangeListener callback = new RealmChangeListener() public void onchange(realmresults<person> results) { // called once the query complete and on every update ; public void onstart() { RealmResults<Person> result = realm.where(person.class).findallasync(); result.addchangelistener(callback);

26 AUTO UPDATING RealmResults<Person> peoples = realm.where(person.class).findall(); peoples.size(); // => 0 addrandomperson(); peoples.addchangelistener( results -> { // results and peoples point are both up to date results.size(); // => 1 peoples.size(); // => 1 );

27 CHANGE EVENTS BUBBLE RealmResults<Person> peoples = realm.where(person.class).findall(); peoples.addchangelistener( results -> { /*... */ ); realm.addchangelistener( results -> { /*... */ );

28 FINE GRAIN CHANGE LISTENERS

29 SAVING UNMANAGED OBJECTS Person obj = new Person(); obj.setid(42); obj.setname("fish"); // Obtain a Realm instance Realm realm = Realm.getDefaultInstance(); // Save to disk realm.begintransaction(); managedperson = realm.copytorealmorupdate(obj); realm.committransaction();

30 SAVING MANAGED OBJECTS // Obtain a Realm instance Realm realm = Realm.getDefaultInstance(); realm.begintransaction(); Person person = realm.createobject(person.class); person.setname("mitchell"); person.setage(27); realm.committransaction();

31 ROLLBACK FAILED TRANSACTIONS try { realm.begintransaction(); Person person = realm.createobject(person.class); person.setname("mitchell"); person.setage(27); realm.committransaction(); catch(exception ex) { // Rollback realm.canceltransaction();

32 RECOMMENDED TRANSACTION STYLE outerrealm.executetransaction(new Realm.Transaction() public void execute(realm realm) { Person person = realm.createobject(person.class); person.setname("mitchell"); person.setage(27); );

33 ASYNCHRONOUS TRANSACTIONS realm.executetransactionasync({ //..., new Realm.Transaction.OnSuccess() public void onsuccess() { // Transaction was a success., new Realm.Transaction.OnError() public void onerror(throwable error) { // Transaction failed and was automatically canceled. );

34 DELETE TRANSACTIONS realm.executetransaction(new Realm.Transaction() public void execute(realm realm) { person.getdog().deletefromrealm(); person.deletefromrealm(); );

35 AGGREGATION RealmResults<User> results = realm.where(user.class).findall(); long sum = results.sum("age").longvalue(); long min = results.min("age").longvalue(); long max = results.max("age").longvalue(); double average = results.average("age"); long matches = results.size();

36

37 ENCRYPTION // Totally not safe key val key = new byte[64]; new SecureRandom().nextBytes(key); val config = new RealmConfiguration.Builder().encryptionKey(key).build(); // Open the Realm with encryption enabled val realm = Realm.getInstance(config);

38 DATA MIGRATIONS

39 JUST DELETE IT RealmConfiguration config = new RealmConfiguration.Builder().deleteRealmIfMigrationNeeded().build()

40 MIGRATIONS RealmConfiguration config = new RealmConfiguration.Builder().schemaVersion(2) // Must be bumped when the schema changes.migration(new MyMigration()) // Migration to run instead of throwing an exception.build()

41 MIGRATIONS RealmMigration migration = new RealmMigration() public void migrate(dynamicrealm realm, long oldversion, long newversion) { RealmSchema schema = realm.getschema(); if (oldversion == 0) { schema.create("person").addfield("name", String.class).addField("age", int.class); oldversion++; if (oldversion == 1) { schema.get("person").addfield("id", long.class, FieldAttribute.PRIMARY_KEY).addRealmObjectField("favoriteDog", schema.get("dog")).addrealmlistfield("dogs", schema.get("dog")); oldversion++;

42 REALM SETUP

43 ANDROID SETUP buildscript { repositories { jcenter() dependencies { classpath "io.realm:realm-gradle-plugin:2.0.0" apply plugin: 'realm-android'

44 ANDROID INIT public class MyApplication extends Application public void oncreate() { super.oncreate(); Realm.init(this); RealmConfiguration config = new RealmConfiguration.Builder().build(); Realm.setDefaultConfiguration(config)

45 SWIFT & OBJECTIVE-C

46 REALM BROWSER

47

48 REALM MOBILE PLATFORM

49 REALM USER SEGREGATION

50 DRAWBACKS Thread confined* Large binary Connections need to be closed

51 ANDROID SIZE COST

52 IOS SIZE COST

53 INSPECT REALM ON ANDROID Realm.init(this); Stetho.initialize( Stetho.newInitializerBuilder(this).enableDumpapp( Stetho.defaultDumperPluginsProvider(this) ).enablewebkitinspector( RealmInspectorModulesProvider.builder(this).build() ).build());

54 ANDROID LIBRARY INTEGRATIONS JSON ( GSON, Moshi ) RxJava Retrofit

55 RXJAVA SUPPORT realm.where(person.class).findallasync().asobservable();

56 RXJAVA REALM SCHEDULER fun Schedulers.newRealmThread(): Scheduler { val backgroundthread = HandlerThread( "RxRealm-BackgroundThread", THREAD_PRIORITY_BACKGROUND ) backgroundthread.start() val backgroundlooper = backgroundthread.looper return AndroidSchedulers.from(backgroundLooper) compile "io.reactivex:rxandroid:$rx_android_version"

57 PRODUCTION READY?

58

59 YES

60 QUESTIONS?

61 Mitchell " GITHUB.COM/MARUKAMI