Serverless mobile applications with Firebase

Serverless mobile applications with Firebase talk given at Droidcon Spain 2016.

Talks about authentication and real time databases.

Transcript

1. Serverless applications with Firebase @alexsimonescu
2. Alexandru Simonescu Blog: http://blog.alexsimo.com Twitter: @alexsimonescu Email: hi@alexsimo.com Software Craftsman. Android Developer. Yoga Lover. “Do what you love. Love what you do.”
5. Madrid Android Developer Group
6. My story..
7. Our mission
8. Serverless
10. Firebase
13. Firebase requirements - Device running Android 2.3 (Ginger Bread) - Google Play Services 9.2.0 - Google Play Services SDK
14. Installation
15. // root build.gradle buildscript {
 repositories {
 jcenter()
 }
 dependencies {
 classpath 'com.android.tools.build:gradle:2.2.0-alpha4'
 classpath 'com.google.gms:google-services:3.0.0'
 }
 }
16. // app build.gradle android {
 compileSdkVersion 23
 buildToolsVersion "23.0.3"
 defaultConfig {
 applicationId “com.alexsimo.sanum" [. . .] apply plugin: 'com.google.gms.google-services'
17. // firebase libraries 
 def version = "9.2.0"
 
 compile "com.google.firebase:firebase-core:${version}" // Analytics
 compile "com.google.firebase:firebase-database:${version}" // Realtime Database
 compile "com.google.firebase:firebase-storage:${version}" // Storage
 compile "com.google.firebase:firebase-crash:${version}" // Crash Reporting
 compile "com.google.firebase:firebase-auth:${version}" // Authentication
 compile "com.google.firebase:firebase-messaging:${version}" // Cloud Messaging
 compile "com.google.firebase:firebase-config:${version}" // Remote Config
 compile "com.google.firebase:firebase-invites:${version}" // Invites / Dynamic Links
 compile "com.google.firebase:firebase-ads:${version}" // AdMob
 compile "com.google.android.gms:play-services-appindexing:${version}" // App Indexing
18. // firebase libraries 
 def version = "9.2.0"
 
 compile "com.google.firebase:firebase-core:${version}" // Analytics
 compile "com.google.firebase:firebase-database:${version}" // Realtime Database
 compile "com.google.firebase:firebase-storage:${version}" // Storage
 compile "com.google.firebase:firebase-crash:${version}" // Crash Reporting
 compile "com.google.firebase:firebase-auth:${version}" // Authentication
 compile "com.google.firebase:firebase-messaging:${version}" // Cloud Messaging
 compile "com.google.firebase:firebase-config:${version}" // Remote Config
 compile "com.google.firebase:firebase-invites:${version}" // Invites / Dynamic Links
 compile "com.google.firebase:firebase-ads:${version}" // AdMob
 compile "com.google.android.gms:play-services-appindexing:${version}" // App Indexing
19. + < v9.20 = ¯\_(ϑ)_/¯
20. // me sad.. D/FirebaseApp: Initialized class com.google.firebase.auth.FirebaseAuth.
 D/FirebaseApp: Initialized class com.google.firebase.iid.FirebaseInstanceId.
 D/FirebaseApp: com.google.firebase.crash.FirebaseCrash is not linked. Skipping initialization.
 I/FirebaseInitProvider: FirebaseApp initialization successful
 W/GooglePlayServicesUtil: Google Play services out of date. Requires 9080000 but found 8489434
 W/FA: Service connection failed: ConnectionResult{statusCode=SERVICE_VERSION_UPDATE_REQUIRED
22. // check play services version 
 int code = GooglePlayServicesUtil.GOOGLE_PLAY_SERVICES_VERSION_CODE;
 Timber.d("VERSION: %s", code);
 
 Deprecated
23. // check play services version 
 int result = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(this);
 switch (result) {
 case ConnectionResult.SERVICE_MISSING:
 case ConnectionResult.SERVICE_DISABLED:
 case ConnectionResult.SERVICE_VERSION_UPDATE_REQUIRED:
 break;
 }

24. // notify errors int result = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(this);
 Dialog dialog = GoogleApiAvailability.getInstance().getErrorDialog(this, result, 123);
 dialog.show();

25. ~ 43MB
26. Let’s build an app!
27. Application requirements
28. Authentication Storage Hosting Database
29. Storage Hosting vs
30. Authentication
31. Authentication validations
33. Account multi linking
34. Email authentication
35. // firebase user properties {
 "FirebaseUser": {
 "uniqueID": "wbNvyz6ENwPiTrjV2KRkEjH78ZMcU",
 "email": "hi@alexsimo.com",
 "name": "Alexandru Simonescu",
 "photoURL": "http://alexsimo.com/avatar.png"
 }
 }

36. firebaseAuth.createUserWithEmailAndPassword(email, password)
 .addOnCompleteListener(this, task -> {
 if (task.isSuccessful()) {
 // user created and logged in
 } else {
 // user not created
 // task.getException().getMessage()
 }
 }); // email and password sign up
37. // email and password sign in firebaseAuth.signInWithEmailAndPassword(email, password) .addOnCompleteListener(task -> {
 if (task.isSuccessful()) {
 // user logged in
 String uuid = task.getResult().getUser().getUid();
 Timber.d("User UUID %s", uuid);
 } else {
 // fail sign in
 // task.getException().getMessage();
 }
 });

38. // authentication listener private FirebaseAuth firebaseAuth;
 private FirebaseAuth.AuthStateListener authStateListener;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 // register listener onStart() and onStop() firebaseAuth = FirebaseAuth.getInstance();
 authStateListener = auth -> {
 FirebaseUser user = auth.getCurrentUser();
 if (user != null) {
 Timber.d("User is logged in");
 } else {
 Timber.d("User is not logged in");
 }
 };
 }
39. // obtain user FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
 // user can be NULL if (user != null) {
 Timber.d("User is signed in");
 } else {
 Timber.d("No user is signed in");
 }

40. // update user FirebaseUser user = provideFirebaseUser();
 
 UserProfileChangeRequest update = new UserProfileChangeRequest.Builder()
 .setDisplayName("Alex")
 .setPhotoUri(Uri.parse("http://alexsimo.com/avatar.png"))
 .build();
 
 user.updateProfile(update) .addOnSuccessListener(aVoid -> Timber.d("User updated!"));

41. // update sensitive data FirebaseUser user = provideFirebaseUser(); 
 AuthCredential credential = EmailAuthProvider .getCredential("hi@alexsimo.com", "verysecret");
 
 user.reauthenticate(credential).addOnCompleteListener(task -> {
 Timber.d("User re-authenticated.");
 updatePassword(user, "muchsecret");
 });
 

42. Social Login
43. Social Login 1. Send Google sign in intent for result 2. Receive response on onActivityResult() 3. Extract sign in result and user credentials 4. Sign in using credentials with Firebase Auth
44. Social Login 1. Send Google sign in intent for result 2. Receive response on onActivityResult() 3. Extract sign in result and user credentials 4. Sign in using credentials with Firebase Auth
45. Social Login 1. Send Google sign in intent for result 2. Receive response on onActivityResult() 3. Extract sign in result and user credentials 4. Sign in using credentials with Firebase Auth
46. Social Login 1. Send Google sign in intent for result 2. Receive response on onActivityResult() 3. Extract sign in result and user credentials 4. Sign in using credentials with Firebase Auth
47. // send google sign in intent @Override
 public void onClick(View v) {
 Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(client);
 startActivityForResult(signInIntent, 1337);
 }

48. // handle onActivityResult @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 
 if (requestCode == 1337) {
 GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data); 
 firebaseAuthWithGoogle(result.getSignInAccount());
 }
 }
49. // sign in with Firebase 
 AuthCredential credential = GoogleAuthProvider .getCredential(acct.getIdToken(), null);
 firebaseAuth.signInWithCredential(credential) .addOnCompleteListener(this, task -> {
 Timber.d("signInWithCredential: onComplete: %s", task.isSuccessful());
 
 if (!task.isSuccessful()) {
 Timber.e("signInWithCredential: %s", task.getException());
 }
 });
50. Anonymous authentication
51. // anonymous sign in 
 firebaseAuth.signInAnonymously() .addOnSuccessListener(authResult -> {
 String uid = authResult.getUser().getUid();
 Timber.d("UID: %s", uid); 
 });

52. // link anonymous to permanent 
 AuthCredential credential = GoogleAuthProvider.getCredential(token, null);
 
 firebaseAuth.getCurrentUser()
 .linkWithCredential(credential)
 .addOnSuccessListener(authResult -> {
 // google account linked to anonymous
 });

53. // link anonymous to permanent 
 AuthCredential credential = GoogleAuthProvider.getCredential(token, null);
 
 firebaseAuth.getCurrentUser()
 .linkWithCredential(credential)
 .addOnSuccessListener(authResult -> {
 // google account linked to anonymous
 });

54. Hosting
55. Hosting 1. Store simple static content: html, css, js 2. Served over secure connection 3. Fast content delivery network
56. Hosting 1. Store simple static content: html, css, js 2. Served over secure connection 3. Fast content delivery network
57. Hosting 1. Store simple static content: html, css, js 2. Served over secure connection 3. Fast content delivery network
58. Storage
59. Storage 1. Store and server user generated content 2. Uploads and downloads on poor network quality 3. On shoulders of Google Cloud Storage
60. Storage 1. Store and server user generated content 2. Uploads and downloads on poor network quality 3. On shoulders of Google Cloud Storage
61. Storage 1. Store and server user generated content 2. Uploads and downloads on poor network quality 3. On shoulders of Google Cloud Storage
62. // upload file 
 byte[] bytes = readFile();
 StorageReference docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
 @Override
 public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
 Timber.d("Bytes transfered: %s", taskSnapshot.getBytesTransferred());
 }
 }).addOnFailureListener(new OnFailureListener() {
 @Override
 public void onFailure(@NonNull Exception e) {
 
 }
 }).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
 @Override
 public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
 Timber.d("Downloadable from %s", taskSnapshot.getDownloadUrl());
 }
 });

63. // sexy upload file byte[] bytes = readFile();
 StorageReference docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask
 .addOnProgressListener(snapshot -> Timber.d("Transfered: %s", snapshot.getBytesTransferred()))
 .addOnFailureListener(e -> Timber.e("Ups! %s", e.getMessage()))
 .addOnSuccessListener(snapshot -> Timber.d("Download: %s", snapshot.getDownloadUrl()));
64. // sexy upload file byte[] bytes = readFile();
 StorageReference docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask
 .addOnProgressListener(snapshot -> Timber.d("Transfered: %s", snapshot.getBytesTransferred()))
 .addOnFailureListener(e -> Timber.e("Ups! %s", e.getMessage()))
 .addOnSuccessListener(snapshot -> Timber.d("Download: %s", snapshot.getDownloadUrl()));
65. // sexy upload file byte[] bytes = readFile();
 StorageReference docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask
 .addOnProgressListener(snapshot -> Timber.d("Transfered: %s", snapshot.getBytesTransferred()))
 .addOnFailureListener(e -> Timber.e("Ups! %s", e.getMessage()))
 .addOnSuccessListener(snapshot -> Timber.d("Download: %s", snapshot.getDownloadUrl()));
66. // sexy upload file byte[] bytes = readFile();
 StorageReference docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask
 .addOnProgressListener(snapshot -> Timber.d("Transfered: %s", snapshot.getBytesTransferred()))
 .addOnFailureListener(e -> Timber.e("Ups! %s", e.getMessage()))
 .addOnSuccessListener(snapshot -> Timber.d("Download: %s", snapshot.getDownloadUrl()));
67. Activity lifecycle and storage 1. Firebase tasks are persistent 2. Pending tasks can be retrieved 3. Continue upload across process kill or restart
68. Activity lifecycle and storage 1. Firebase tasks are persistent 2. Pending tasks can be retrieved 3. Continue upload across process kill or restart
69. Activity lifecycle and storage 1. Firebase tasks are persistent 2. Pending tasks can be retrieved 3. Continue upload across process kill or restart
70. byte[] bytes = readFile();
 docRef = storageReference.child(buildFileName());
 
 UploadTask uploadTask = docRef.putBytes(bytes);
 uploadTask.addOnProgressListener(
 snapshot -> { /* do stuff */ })
 .addOnFailureListener(e -> { /* do stuff */ })
 .addOnSuccessListener(s -> { /* do stuff */ });
 private StorageReference docRef;
71. protected void onSaveInstanceState(Bundle outState) {
 super.onSaveInstanceState(outState);
 
 outState.putString(UPLOAD_KEY, docRef.toString());
 }
 private StorageReference docRef;
72. protected void onRestoreInstanceState(Bundle saved) {
 super.onRestoreInstanceState(saved);
 
 String ref = saved.getString(UPLOAD_KEY);
 
 StorageReference file = getFirebase().getReferenceFromUrl(ref);
 
 UploadTask task = file.getActiveUploadTasks().get(0);
 
 task.addOnCompleteListener(task1 -> { /* handle task */ });
 }

73. // and download? 
 File file = new File(getCacheDir().getAbsolutePath() + "/ temp.png");
 
 StorageReference ref = storageReference.child("avatar.png");
 
 ref.getFile(file).addOnSuccessListener(
 taskSnapshot -> Timber.d("Downloaded! %s", file.exists()));

74. Storage tips 1. Limit upload filesize 2. Download to local file, not in memory 3. Filters, crops and more, on client side
75. Storage tips 1. Limit upload filesize 2. Download to local file, not in memory 3. Filters, crops and more, on client side
76. Storage tips 1. Limit upload filesize 2. Download to local file, not in memory 3. Filters, crops and more, on client side
77. Storage validations
78. // just auth users service firebase.storage {
 match /b/<project-url>.appspot.com/o {
 match /{allPaths=**} {
 allow read, write: if request.auth != null;
 }
 }
 }
79. // file size validation service firebase.storage {
 match /b/<project-url>.appspot.com/o {
 
 match /{allPaths=**} {
 allow read, write: if request.auth != null;
 }
 
 match /images/{imageId} {
 // only images less than 5MB
 allow write: if request.resource.size < 5 * 1024 * 1024
 && request.resource.metadata.contentType.matches('image/.*');
 }
 }
 }
80. https://firebase.google.com/docs/reference/security/storage/#request
81. // user based validation service firebase.storage {
 match /b/<project-url>.appspot.com/o {
 
 match /public/{imageId} {
 allow write: if request.auth != null;
 }
 
 match /users/{userId}/{imageId} {
 allow write: if request.auth.uid == userId;
 }
 }
82. // user based validation service firebase.storage {
 match /b/<project-url>.appspot.com/o {
 
 match /public/{imageId} {
 allow write: if request.auth != null;
 }
 
 match /users/{userId}/{imageId} {
 allow write: if request.auth.uid == userId;
 }
 }
83. Database
86. Realtime Offline Secure Documental
87. Realtime and Offline
88. Offline support
89. FirebaseDatabase.getInstance().setPersistenceEnabled(true);
90. DatabaseReference recipes = rootRef.child("recipes");
 recipes.keepSynced(true);

91. NoSQL?
92. JSON?
93. NoSQL JSON
94. Tree of lists and objects
95. // first approach 
 DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
 
 DatabaseReference recipes = rootRef.child("recipes");
 
 recipes.child(buildId()).setValue("Pancakes");

97. // storing objects DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
 
 DatabaseReference recipes = rootRef.child("recipes");
 
 String id = buildId();
 
 Recipe recipe = new Recipe(id, "Eggs with potatoes", "Yummy eggs with potatoes");
 
 recipes.child(id).setValue(recipe);

99. // first write 
 DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
 
 DatabaseReference recipes = rootRef.child("recipes");
 
 recipes.child(buildId()).setValue("Pancakes");

100. // more writing recipes.child(buildId()).setValue("My awesome recipe");
 
 recipes.child("My awesome recipe").push();
 
 recipes.child("4fsh7sx").updateChildren(Map<String, Object>);
 
 recipes.child("4fsh7sx").runTransaction(new Transaction.Handler {...});
101. DatabaseReference rootRef = getRootReference();
 DatabaseReference recipes = rootRef.child("recipes");
 
 recipes.addValueEventListener(new ValueEventListener() {
 
 public void onDataChange(DataSnapshot snapshot) {
 for (DataSnapshot child : snapshot.getChildren()) {
 Timber.d("Key %s", child.getKey());
 }
 }
 
 public void onCancelled(DatabaseError error) {
 // do stuff
 }
 }); // read and listen changes
102. DatabaseReference recipeRef = recipes.child("004");
 
 recipeRef.addListenerForSingleValueEvent(new ValueEventListener() {
 
 public void onDataChange(DataSnapshot snapshot) { 
 Recipe recipe = snapshot.getValue(Recipe.class); 
 }
 }); // read + map objects
103. BONUS
105. Structuring data
106. Structuring data 1. Plan how data is going to be saved 2. Map screens to JSON trees 3. Avoid nested data 4. Keep structures flat
107. Structuring data 1. Plan how data is going to be saved 2. Map screens to JSON trees 3. Avoid nested data 4. Keep structures flat
108. Structuring data 1. Plan how data is going to be saved 2. Map screens to JSON trees 3. Avoid nested data 4. Keep structures flat
109. Structuring data 1. Plan how data is going to be saved 2. Map screens to JSON trees 3. Avoid nested data 4. Keep structures flat
111. Something is missing..
112. Server side logic
113. Server side logic
114. https://cloud.google.com/solutions/mobile/mobile-firebase-app-engine-flexible
116. Forgetting Firebase
117. Remember Parse?
118. Decouple
119. Decouple
120. Decouple
123. https://twitter.com/JakeWharton/status/752162360916258816
124. // convert async callbacks to rx private Observable<User> createFirebaseUser( String email, String password) {
 
 return Observable.fromAsync(emitter -> auth.createUserWithEmailAndPassword(email, password)
 .addOnSuccessListener(authResult -> {
 FirebaseUser user = authResult.getUser();
 emitter.onNext(new User(user.getUid(), user.getEmail()));
 emitter.onCompleted();
 })
 .addOnFailureListener(emitter::onError), AsyncEmitter.BackpressureMode.BUFFER);
 }
125. REST API
126. Firebase Myths
127. Myths 1. Production ready 2. Price 3. Scalability
128. Myths 1. Production ready 2. Price 3. Scalability
129. Myths 1. Production ready 2. Price 3. Scalability
130. Firebase tips
131. Tips and tricks 1. Cache data as much as posible 2. Compare predefined plan with pay as you go 3. Take care with migrations 4. Versionate datasource entities
132. Tips and tricks 1. Cache data as much as posible 2. Compare predefined plan with pay as you go 3. Take care with migrations 4. Versionate datasource entities
133. Tips and tricks 1. Cache data as much as posible 2. Compare predefined plan with pay as you go 3. Take care with migrations 4. Versionate datasource entities
134. Tips and tricks 1. Cache data as much as posible 2. Compare predefined plan with pay as you go 3. Take care with migrations 4. Versionate datasource entities
135. Links • Serverless architectures http://martinfowler.com/articles/serverless.html • Firebase official documentation https://firebase.google.com/docs • Firebase official documentation firebase-community.slack.com • The key to Firebase security https://www.youtube.com/watch?v=PUBnlbjZFAI
136. + Inspiring people
137. Questions?
138. Thanks! @alexsimonescu