Introduction to Firebase (Realtime Database)

KelasMobile Malang Meetup 3.

2016/09/20

Transcript

1. KelasMobile Firebase Adi Nugroho @adinugroho
2. History Realtime Database & Authentication April 2012 October 2014 (Google)
4. GOOGLE IO 2016 Some still in beta & in development
5. Dashboard
7. Realtime Database
8. Realtime Database • Store • Sync • Collaboration ! • Work Offline ✈ • Multiplatform (Android, iOS, Web, IOT, etc) # Realtime database in Firebase ▶ NoSQL ▶ JSON Firebase uses Websocket
9. Android • Project Gradle classpath 'com.google.gms:google-services:3.0.0' • App Gradle // auto add firebase analytics compile 'com.google.firebase:firebase-core:9.4.0' compile 'com.google.firebase:firebase-database:9.4.0' . . . apply plugin: 'com.google.gms.google-services'
10. Android • Manifest <uses-permission android:name="android.permission.INTERNET" /> • google-services.json
11. iOS • Pod # auto add firebase analytics pod 'Firebase' pod 'Firebase/Database' • GoogleService-Info.plist • AppDelegate init FIRApp.configure()
12. Realtime Database Demo
13. Note • DataSnapshot is immutable ! • DataSnapshot value : Android HashMap or POJO (Plain Old Java Object). iOS Dictionary. • Key must be String. Value can be primitive types and Android HashMap or iOS Dictionary. • Android : Firebase handle Object " JSON. • Use @Exclude to exclude field.
14. Note • No native support of array / list • Array will be saved as hashmap with integer key • When retrieved will be returned as array / list
15. Offline Capability Note • Transaction is queued & committed ONLY when app is on foreground. • Show warning when data has not been saved online. • Manually handle transaction when app is restarted.
16. Write Data • Android setValue( Object ) iOS setValue( AnyObject ) • Android updateChildren( HashMap<String, Object> ) iOS updateChildValues( Dictionary ) • update spesific child / children • passing null = remove the child
17. updateChildren HashMap<String, Object> updatedChildren = new HashMap<>(); updatedChildren.put("price", "$ 21.000.000"); HashMap<String, Object> winnerNode = new HashMap<>(); winnerNode.put("winner", "Digital Chaos"); updatedChildren.put("info", winnerNode); dotaRef.updateChildren( updatedChildren );
18. updateChildValues let param : [String: Any] = [ "price": "$ 21.000.000", "info": [ "winner": "Digital Chaos" ] ] dotaRef.updateChildValues(param)
19. Write Data • Android push() iOS childByAutoId() • only return reference to auto generated child • Child has unique ID & sorted by date • like append array • runTransaction( Transaction.Handler ) • multiple concurrent operations • keep data from being corrupted • e.g counter
20. runTransaction upvotesRef.runTransaction(new Transaction.Handler() { @Override public Transaction.Result doTransaction(MutableData currentData) { Integer value = (Integer) currentData.getValue(); // must handle null if (value == null) { value = 0; } currentData.setValue( value + 1 ); return Transaction.success(currentData); //we can also abort by calling Transaction.abort() } @Override public void onComplete(FirebaseError firebaseError, boolean committed, DataSnapshot currentData) { //This method will be called once with the results of the transaction. } });
21. Remove Data • removeValue() • set this reference value to null
22. Write & Remove Data • all except push() have completion callback. • called when operation is completed dotaRef.updateChildren(updatedChildren, new DatabaseReference.CompletionListener() { @Override public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) { } });
23. Read Data • addValueEventListener • observeEventType( FIRDataEventType.Value , (snapshot) -> Void ) • addChildEventListener • observeEventType( FIRDataEventType.ChildChanged, (snapshot) -> Void ) • addListenerForSingleValueEvent • observeSingleEventOfType( .Value, (snapshot) -> Void )
24. Use ChildEventListener or FIRDataEventTypeChildChanged to monitor children
25. More • Query (sort, limit, filter) • FirebaseUI • FirebaseListAdapter • FirebaseRecyclerViewAdapter • Efficient data structuring • Firebase Auth • Offline / Disk persistance • Persistence handling • Detect connection
26. Pricing https://firebase.google.com/pricing/
27. Best For • Early prototyping. • Low - medium frequency.
28. Alternatives • Websocket + Database • Parse Server • Simperium
29. Links • https://firebase.google.com/docs/ • https://firebase.google.com/docs/database/ • Udacity : Firebase Essential for Android • https://classroom.udacity.com/courses/ud009 • Legacy firebase. • Existing firebase app : • https://firebase.google.com/support/guides/firebase-android • https://firebase.google.com/support/guides/firebase-ios
30. @adinugroho