Hands on Realm Mobile Platform

Talk at GDG DevFest 2016 in Düsseldorf.

Realm Mobile Platform is a brand new tool by Realm. It was just released less than one month ago and instantly gained a lot of attention among the mobile development community. It combines the popular Realm Mobile Database with the complete new Realm Object Server. Its objective is to become the perfect backend for the next generation of reactive mobile apps. But what’s behind this promise? How does it work? What’s so new and why should you care?

Transcript

1. HANDS-ON REALM MOBILE PLATFORM André Diermann ¬ ® q2ad a11n
3. FEATURES Free Pro manage all your passwords ( ( protected by 512-bit encryption ( ( create custom fields ( ( realtime cloud sync ) ( protected cloud backup ) (
4. QUIZ HOW MANY LINES OF CODE? Feature Lines of code Manage passwords (create/read/update/delete) 5 Encryption 1 Custom fields (create/read/update/delete) 3 Synchronization (sign-in, sign-up, sync) 4
5. REALM Realm is an open source, cross-platform mobile database technology used by more than a billion people worldwide.
6. REALM MILESTONES When? What? Jul 2014 launched Realm May 2016 released 1.0.0 Sep 2016 introduced Realm Mobile Platform
7. REALM MOBILE PLATFORM (Source: , accessed 2016-10-22) https://realm.io/news/introducing-realm-mobile-platform/
8. SETUP //project level build.gradle buildscript { repositories { ... } dependencies { classpath "io.realm:realm-gradle-plugin:2.0.2" } } //application level build.gradle apply plugin: 'realm-android'
9. REALMS a Realm is a database it contains different kinds of objects which are mapped to one file on disk Realms are configurable and thread-safe
10. EXAMPLE // Initialize Realm in your Application Realm.init(this); RealmConfiguration config = new RealmConfiguration.Builder().build(); Realm.setDefaultConfiguration(config); // Obtain and close a Realm instance in your Activity realm = Realm.getDefaultInstance(); doSomeStuff(); realm.close();
11. MODELING
12. MODELING
13. MODELS //Option 1: Extending RealmObject public class Password extends RealmObject {...} password.addChangeListener(listener); //Option 2: Implementing RealmModel @RealmClass public class Password extends SpecialClass implements RealmModel {...} RealmObject.addChangeListener(password, listener);
14. MODELS Field types, annotations, auto-updating public class Password extends RealmObject { @PrimaryKey private int id; private Date created; private byte[] icon; @Required private String password; @Ignore private long indexInList; // ... }
15. RELATIONS Any two Realm models can be linked together public class Password extends RealmObject { // ... // one-to-one and many-to-one private Category category; // one-to-many and many-to-many private RealmList<CustomField> customFields; // ... }
16. READING DATA
17. READING DATA // queries are lazy (data is never copied) realm.where(Password.class).findAll(); // fluent interface allows convenient multi-clause queries realm.where(Password.class) .equalTo("id", id) .greaterThan("created", today) .findFirst() // it's possible to query relationships as well realm.where(Password.class) .contains("fields.name", "Amazon") .findAll();
18. WRITING DATA
19. WRITING DATA // write operations must be wrapped in transactions realm.beginTransaction(); // allow solid data state realm.copyToRealm(password) // transactions can either be committed or cancelled realm.commitTransction(); // use transaction blocks realm.executeTransaction(realm1 -> realm1.copyToRealm(password));
20. EXCURSUS (UN)MANAGED OBJECTS // Unmanaged Password password = new Password(...); password.setUsername("user"); //this change is not persisted realm.executeTransaction(realm1 -> realm1.copyToRealm(password)); // Managed Password password; realm.executeTransaction(realm1 -> { password = realm1.createObject(Password.class); password.setUsername("user"); //this change is persisted //and propagated }); password.setPassword("pass"); //this is not allowed
21. UPDATES
22. UPDATES RealmObjects are live and auto-updating never have to be refreshed modifying objects update query results immediately.
23. THREADING Realm works across threads each thread always has a consistent view of the data illegal states are impossible
24. ENCRYPTION // should be stored in and obtained from Android keystore byte[] key = new byte[64]; new SecureRandom().nextBytes(key); RealmConfiguration config = new RealmConfiguration.Builder() .encryptionKey(key) .build(); Realm realm = Realm.getInstance(config);
25. MIGRATION When schema changes over time // 1. default: exception is thrown // 2. simple: new RealmConfiguration.Builder() .deleteRealmIfMigrationNeeded() .build(); // 3. custom: new RealmConfiguration.Builder() .schemaVersion(2) .migration(migrataion) .build();
26. MIGRATION RealmMigration migration = new RealmMigration() { @Override public void migrate(DynamicRealm realm, long oldVersion, long newVersion) { RealmSchema schema = realm.getSchema(); if (oldVersion++ == 0) { // adapt schema from version 0 to 1 } if (oldVersion++ == 1) { // adapt schema from version 1 to 2 } // more versions } }
27. BETA NOTICE Realm Mobile Platform is in beta state. API may change without further notice.
28. SYNCHRONIZATION TWO-WAY REALTIME DATA-SYNC How many lines of code?
29. SYNCHRONIZATION TWO-WAY REALTIME DATA-SYNC In your application build.gradle realm { syncEnabled = true; }
30. SIGN-UP / SIGN-IN
31. SIGN-UP / SIGN-IN // registration Credentials credentials = Credentials.usernamePassword(username, password, true); // built-in: username / password Credentials credentials = Credentials.usernamePassword(username, password, false); // third-party: Google, Facebook (, iCloud) Credentials google = Credentials.google(token); Credentials facebook = Credentials.facebook(token); // authentication String authURL = "http://my.realm-auth-server.com:9080/auth"; User user = User.login(credentials, authURL);
32. REALM OBJECT SERVER Available for Ų and ŵ
33. REALM OBJECT SERVER Download macOS bundle and run start-object-server.command
34. REALM BROWSER Only available for OSX
35. REALM BROWSER Admin token OSX /.../realm-object- server/admin_token.base64 Linux /etc/realm/admin_token.base64
36. DEMO https://github.com/a11n/devfest-2016-realm
37. CONCLUSION Realm really speeds up app development very fast learning curve most convenient and mature DB replacement* there are alternatives: Firebase, ...
38. THANK YOU FOR YOUR ATTENTION. Q&A ¬ ® q2ad a11n
39. BACKUP
40. TESTING DO NOT TEST REALM - TEST YOUR BL // use in-memory Realm RealmConfiguration config = new RealmConfiguration.Builder() .inMemory().name("test-realm").build(); realm = Realm.getInstance(config); // Assign - Act - Assert Password expected = createDummyPassword(); copyToRealm(expected); Password actual = interactor.readPassword(1); assertThat(actual, equalTo(expected));
41. RXJAVA is a first-class citizen in Realm just combine Obeservables from Realm with other sources, e.g. Retrofit Observable<Password> passwordsFromRealm = realm.where(Password.class).findAllAsync().asObservable(); Observable<Password> passwordsFromRetrofit = passwordService.loadPasswords(); Observable.mergeDelayError( passwordsFromRealm, passwordsFromRetrofit) .subscribe(...);