Can mobile developers survive without a backend? How & Why?

1. BACKENDLESS
APPS
HOW AND WHY

2. SPEAKERS
ROBERTO ORGIU
&
MATTEO BONIFAZI
We are actually there !

3. ENGAGEMENT &
CONTENT

4. ENGAGEMENT &
CONTENT

5. ENGAGEMENT
> Who's your user
> Users want new content

6. WHO’S YOUR
USER

7. END-TO-END
AUTHENTICATION SYSTEM
ENGINEERING NIGHTMARE

8. 54%USERS WILL QUIT
BEFORE DOING YET-ANOTHER-SIGNUP

9. TEMPORARY
ANONYMOUSACCOUNTS

10. ACCEPT ALL THE SYSTEMS

11. compile 'com.google.firebase:firebase-auth:10.2.1'

12. AUTHENTICATE ANONYMOUSLY
mAuth.signInAnonymously()
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
Log.d(TAG, "signInAnonymously:success");
FirebaseUser user = mAuth.getCurrentUser();
updateUI(user);
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInAnonymously:failure", task.getException());
Toast.makeText(AnonymousAuthActivity.this, "Authentication failed.",
Toast.LENGTH_SHORT).show();
updateUI(null);
}
// ...
}
});

13. EVERY ANONYMOUS USER IS TRACKED

14. LET'S LOGIN BY FACEBOOK PROVIDER
// Initialize Facebook Login button
mCallbackManager = CallbackManager.Factory.create();
facebookLoginButton.setReadPermissions("email", "public_profile");
facebookLoginButton.registerCallback(mCallbackManager, new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
Log.d(TAG, "facebook:onSuccess:" + loginResult);
handleFacebookAccessToken(loginResult.getAccessToken());
}
});

15. HANDLE THE TOKEN & SEND TO FIREBASE
private void handleFacebookAccessToken(AccessToken token) {
AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
mAuth.signInWithCredential(credential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
Log.d(TAG, "signInWithCredential:success");
FirebaseUser user = mAuth.getCurrentUser();
...
} else {
// Signature failed somehow...
}
}
});
}

16. FROM ANONYMOUS TO PERMANENT
AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
mAuth.getCurrentUser().linkWithCredential(credential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
FirebaseUser user = task.getResult().getUser();
} else {
Log.w(TAG, "linkWithCredential:failure", task.getException());
...
}
// ...
}
});

17. AFTER ALL WE WOULD LIKE TO SIGNOUT
public void signOut() {
//Signout from Firebase
mAuth.signOut();
//Signout from the specif provider - Facebook in this case
LoginManager.getInstance().logOut();
...
}

18. FIREBASE IS
MORE
POWERFUL
WITH AUTH

19. USERS WANT NEW CONTENT

20. HOW DO WE RE-ENGAGE
THEM?

21. PUSH
NOTIFICATIONS

23. compile 'com.google.firebase:firebase-messaging:10.2.1'

24. IT JUST WORKS™
We might want more control

25. IMPLEMENTING PUSH MANAGEMENT
Extend FirebaseMessagingService
> Notifications in foreground apps
> Receive data payload
> Send upstream messages

26. IMPLEMENTING PUSH MANAGEMENT
<service android:name=".PushService">
<intent-filter>
<action android:name="com.google.firebase.MESSAGING_EVENT"/>
</intent-filter>
</service>

27. IMPLEMENTING PUSH MANAGEMENT
class PushService : FirebaseMessagingService() {
override fun onMessageReceived(remoteMessage: RemoteMessage) {
...
}
override fun onDeletedMessages() {
...
}
}

28. IMPLEMENTING PUSH MANAGEMENT
App state Notification Data Both
Foreground onMessageRece
ived()
onMessageRece
ived()
onMessageRece
ived()
Background System tray onMessageRece
ived()
system tray!
> Notification in the system tray, Data in extras of the intent.

29. IMPLEMENTING TOKEN MANAGEMENT
Extend FirebaseInstanceIdService
> Handle token creation and rotation
> Needed to target single device or group them

30. IMPLEMENTING TOKEN MANAGEMENT
<service android:name=".TokenManagementService">
<intent-filter>
<action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
</intent-filter>
</service>

31. IMPLEMENTING TOKEN MANAGEMENT
class TokenManagementService : FirebaseInstanceIdService() {
override fun onTokenRefresh() {
val token = FirebaseInstanceId.getInstance().token
}
}

32. ENGAGEMENT &
CONTENT

33. ENGAGEMENT &
CONTENT

34. CONTENT
> Data
> Computation of the data

35. WHERE APPS STORE
CONTENT?

36. CLOUD STORAGE

37. CDNIS NOT A PROBLEM
ANYMORE

38. compile 'com.google.firebase:firebase-storage:10.2.1'

39. // Create a storage reference from our app
StorageReference storageRef = storage.getReference();
// Create a reference to filename
StorageReference mountainsRef = storageRef.child("pippo.jpg");
// Create a reference to 'images/pippo.jpg'
StorageReference mountainImagesRef = storageRef.child("images/pippo.jpg");

40. UPLOAD THE FILE
Uri file = Uri.fromFile(new File("path/to/images/simpaty.jpg"));
StorageReference riversRef = storageRef.child("images/"+file.getLastPathSegment());
uploadTask = riversRef.putFile(file);
// Register observers to listen for when the download is done or if it fails
uploadTask.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception exception) {
// Handle unsuccessful uploads
}
}).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
// taskSnapshot.getMetadata() contains file metadata such as size, content-type, and download URL.
Uri downloadUrl = taskSnapshot.getDownloadUrl();
}
});

41. DOWNLOAD THE FILE
fileRef = storageRef.child("images/local.jpg");
File localFile = File.createTempFile("images", "jpg");
fileRef.getFile(localFile).addOnSuccessListener(new OnSuccessListener<FileDownloadTask.TaskSnapshot>() {
@Override
public void onSuccess(FileDownloadTask.TaskSnapshot taskSnapshot) {
// Local temp file has been created
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception exception) {
// Handle any errors
}
});

42. MONITOR UPLOAD/DOWNLOAD TASK
Task state Task action Listener Type
Pause pause() OnPausedListener
Failure/Cancel cancel() OnFailureListener
Resume resume() OnProgressListener
Success -- OnSuccessListener

43. BUT WHERE IS MY
BACK END?

44. REALTIMEIS EVERYTHING

45. compile 'com.google.firebase:firebase-database:10.2.1'

46. WRITE TO YOUR DATABASE
// Write a message to the database
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("node_XX");
myRef.setValue("Hello, World!");

47. LISTEN AND READ FOR ANY VALUE EVENTS
// Read from the database
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
String value = dataSnapshot.getValue(String.class);
Log.d(TAG, "Value is: " + value);
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
Log.w(TAG, "Failed to read value.", error.toException());
}
});

48. AUTOMAGIC
SYNCHRONIZATION

49. DISK PERSISTENCE
FirebaseDatabase.getInstance().setPersistenceEnabled(true);

50. COMPUTATION OF THE
DATA

51. CLOUD FUNCTIONS
> Run without a backend
> No maintenance
> Automatic scaling
> Detached from the client
> Based on triggers

52. BUT THERE IS A
CATCH

54. JAVASCRIPTACTUALLY, NODE.JS BUT
STILL...

55. WAIT...

56. KOTLINTO THE RESCUE

57. GETTING STARTED
npm install -g firebase-tools
firebase login
firebase init functions

58. GETTING STARTED
npm install -g firebase-tools
firebase login
firebase init functions
npm install kotlin --save

59. myproject
+- .firebaserc # Hidden file that helps you quickly switch between
| # projects with `firebase use`
|
+- firebase.json # Describes properties for your project
|
+- functions/ # Directory containing all your functions code
|
+- package.json # npm package file describing your Cloud Functions code
|
+- index.js # main source file for your Cloud Functions code
|
+- node_modules/ # directory where your dependencies (declared in
# package.json) are installed

60. myproject
+- .firebaserc
|
+- firebase.json
|
+- functions/
|
+- src/
|
+- main/
|
+- kotlin/ # we put our code here

61. Index.kt
external fun require(module: String): dynamic
external val exports: dynamic

62. Index.kt
fun main(args: Array<String>) {
var functions = require('firebase-functions');
exports.myFunc = functions.https.onRequest {req, res ->
res
.status(200)
.type("application/json")
.send(json)
}
}

63. BUILD & DEPLOY
./gradlew build
$ firebase deploy --only functions

64. TRIGGERS
> Realtime database
> Authentication
> Analytics
> Cloud Storage
> HTTP

65. AND...

66. UNIT TESTS

67. THANKS@mbonifazi | @_tiwiz