Modern way of android development

1. Android development
Modern way of android development

2. Who I am
Gregoire BARRET
Web: www.smartsoftasia.com
Email: greg@smartsoftasia.com

3. Summary
1. Application pattern
2. Dependency injection
3. Reactive programming
4. Glide and OkHttp
5. Annotation
6. Testing
7. Kotlin
8. Future of android development

4. Application pattern

5. ● Gold activity class
● Spaghetti code
● No architecture
Activity
Model
Business
logic
Database
Network
No patternBefore

6. Controller
Model View
● Layer separation
● Readable
● Reusable
Now MVC

7. ● Model not update the
view
● Flexibility
● More android way
Presenter
Model View
MVPNow

8. Presenter
Model
View
● Interface
● Fix inclusion
● Life cycle
MVP for androidNow

9. ViewModel
Model View
● Propagation of change
● Many to one
relationship
● Require binder
MVVMNow

10. Activity XML
private void
setViewModel(ViewModel viewModel){
binding.setViewModel(viewModel);
}
<TextView
<!-- -->
android:text="@{viewModel.name}"/>
MVVM + DataBindingNow

11. Dependency injection

12. What is dependency injection
● Every application have a kind of dependency injection.
● Model need an other model
Post
message
Message
API
HTTP
Client
Before

13. What is dependency injection
public class HttpClient {
public HttpClient(){
}
public void execute(Request request) {
//TODO: send request
}
}
Before

14. What is dependency injection
public class MessageApi {
private HttpClient httpClient;
public MessageApi(HttpClient httpClient){
this.httpClient = httpClient;
}
public void sendMessage(String user, String message){
httpClient.execute(new Request(user, message));
}
}
Before

15. What is dependency injection
public class SendMessage {
private MessageApi messageApi;
private String user;
public SendMessage(MessageApi messageApi, String user) {
this.messageApi = messageApi;
this.user = user;
}
public void send(String message){
messageApi.sendMessage(user, message);
}
}
Before

16. What is dependency injection
HttpClient httpClient = new HttpClient();
MessageApi messageApi = new MessageApi(httpClient);
SendMessage sendMessage = new SendMessage(messageApi,
"user");
sendMessage.send("Hello");
Before

17. What is dependency injection
Post
message
Message
API
HTTP
Client
Post
message

18. What is dependency injection
Post
message
Message
API
HTTP
Client
Post
message

19. Dagger 2
● Developped by Google
● Work with proguard
● Fast
● Low configurations
● Multiple injection type
○ Constructor
○ Field
○ Method
Now

20. Module
● Class hold all dependencies
● Work with a Component
● Bridge between Module and
Injection
@Module
public class MessageModule {
@Provide
@Singleton
HttpClient provideHttpClient(){
return new HttpClient();
}
@Provide
@Singleton
MessageApi provideMessageApi(HttpClient httpClient){
return new MessageApi(httpClient);
}
@Provide
SendMessage
provideSendMessage(MessageApi messageApi){
return new SendMessage(messageApi, "User");
}
}
Now

21. Application
public class Application {
@Inject SendMessage sendMessage;
public void main(){
sendMessage.send("Hello");
}
}
Now

22. Reactive X

23. Threading
HTTP
Client
Activity
AsyncTask
Before

24. Threading
HTTP
Client
Activity
Thread
Before

25. Included Listener
getApi(new ResultListener() {
@Override
public void onSuccess() {
getApi(new ResultListener() {
@Override
public void onSuccess() {
//TODO
}
});
}
});
Before

26. ReactiveX (RxJava)
An API for asynchronous programming
with observable streams

27. ReactiveX (RxJava)
Functional Operation
Observable
Observer

28. Observer
onNext
onComplete
onError

29. Observable
create{ onNext( ); onNext( ); onComplete(); }

30. Functional Operation
map()
take(2)

31. Combining
Combine()

32. Implementation
Observable.just(1, 2, 3, 4)
.map((Func1) (i) → { return String.valueOf(i); })
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe((Action1) (String) →{ Log.d("", s); };
Now

33. Rx Java
Presentation
Layer
Domain Layer Data Layer
MVP Interactor
POJO
API
Database
Interface
Interface
Now

34. Http library

35. Application Web API
JSON

36. Old way, manually
public static boolean postUserName(final Context context, final String id, final String
userName){
String serverUrl = BaseAppConfig.BASE_URL + ApiPreferences.USER_API;
serverUrl += "?id=" + id;
long backoff = BACKOFF_MILLI_SECONDS + random.nextInt(1000);
for (int i = 1; i <= MAX_ATTEMPTS; i++) {
try {
post(serverUrl, null, userName);
return true;
} catch (IOException e) {
if (i == MAX_ATTEMPTS) {
break;
}
try {
Thread.sleep(backoff);
} catch (InterruptedException e1) {
Thread.currentThread().interrupt();
return false;
}
backoff *= 2;
}
}
return false;
}
private static void post(String endpoint, Map<String, String> params, String
token, String apiKey)
throws IOException {
URL url = null;
try {
url = new URL(endpoint);
} catch (MalformedURLException e) {
}
if (url==null)return;
HttpURLConnection conn = null;
try {
conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("X-Locale", "en");
int status = conn.getResponseCode();
//TODO: Code for read input stream
} finally {
if (conn != null) {
conn.disconnect();
}
}
}
Before

37. Retrofit
public interface UserService {
@GET("user/{user_id}")
User getUser(@Path("user_id") int userId);
}
NowNow

38. Retrofit
Retrofit
Gson OkHttp
Now

39. Retrofit
OkHttpClient client = new OkHttpClient.Builder().build();
retrofit = new Retrofit.Builder().baseUrl(AppConfig.BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(new
GsonBuilder().create()))
.build();
userService = retrofit.create(UserService.class);
Now

40. Retrofit
OkHttpClient client = new OkHttpClient.Builder().build();
retrofit = new Retrofit.Builder().baseUrl(AppConfig.BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(new
GsonBuilder().create()))
.build();
userService = retrofit.create(UserService.class);
Now

41. Retrofit
OkHttpClient client = new OkHttpClient.Builder().build();
retrofit = new Retrofit.Builder().baseUrl(AppConfig.BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(new
GsonBuilder().create()))
.build();
userService = retrofit.create(UserService.class);
Now

42. Retrofit
OkHttpClient client = new OkHttpClient.Builder().build();
retrofit = new Retrofit.Builder().baseUrl(AppConfig.BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(new
GsonBuilder().create()))
.build();
userService = retrofit.create(UserService.class);
Now

43. Retrofit
OkHttpClient client = new OkHttpClient.Builder().build();
retrofit = new Retrofit.Builder().baseUrl(AppConfig.BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(new
GsonBuilder().create()))
.build();
userService = retrofit.create(UserService.class);
Now

44. Retrofit
User user = restclient.getUserService.getUser(5);
Now

45. Annotation

46. What An annotation can do?
Provide informations
for the compiler
Allow runtime
processing
Allow compile time
processing

47. Bind view example
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user);
TextView nameTextView = (TextView) findViewById(R.id.textView_user_name);
TextView phoneTextView = (TextView)
findViewById(R.id.textView_user_phone);
ImageView profileImageview =
(ImageView)
findViewById(R.id.imageView_user_profile);
Button callButton = (Button) findViewById(R.id.button_call);
}
Before

48. Butterknife
@BindView(R.id.button_friendprofile_block)
protected TextView nameTextView;
@BindView(R.id.button_friendprofile_block)
protected TextView phoneTextView;
@BindView(R.id.button_friendprofile_block)
protected ImageView profileImageview;
@BindView(R.id.button_friendprofile_block)
protected Button callButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user);
ButterKnife.bind(this);
}
Now

49. Skip enum
public static final String TYPE_ONE = "one";
public static final String TYPE_TWO= "two";
@StringDef({ TYPE_ONE, TYPE_TWO})
@Retention(RetentionPolicy.SOURCE)
public @interface MyType {}
@MyType private String type;
public enum MyType {
TYPE_ONE,
TYPE_TWO
}
private MyType type;
NowBefore

50. Example of library that use annotations
● ButterKnife
● Dagger
● Retrofit
● Real
● Gson
● ...

51. Testing

52. Testing framework

53. Testing framework

54. Testing
Local unit test
Instrument test
UI test

55. CI PipelineCode
CI Pipeline
Prod
Beta

57. What is kotlin
● Programing language
● Interoperable
● Concise
● Safe
● Versatile

58. What does it look like
class Greeter(val name: String) {
fun greet() {
println("Hello, $name")
}
}
fun main(args: Array<String>) {
Greeter(args[0]).greet()
}

59. Kotlin over java
Null safety:
b?.length

60. Kotlin over java
Null safety:
b?.length
Data class:
data class User(val name: String, val age: Int)

61. Kotlin over java
Null safety:
b?.length
Data class:
data class User(val name: String, val age: Int)
Smart cast:
fun demo(x: Any) {
if (x is String) {
print(x.length) }
}

62. Kotlin over java
Lambda expression:
max(strings, { a, b -> a.length < b.length })

63. Kotlin over java
Lambda expression:
max(strings, { a, b -> a.length < b.length })
Range:
for (i in 1..4) print(i)

64. Kotlin over java
Lambda expression:
max(strings, { a, b -> a.length < b.length })
Range:
for (i in 1..4) print(i)
And much more...

65. The ugly
● Slow compile time
● Larger app
● Issue with annotation processor
● Testing
● No static analyzer

66. Future of
android

67. Next billion user
77M
223M
538M
1B
1.4B
2011 2012 2013 2014 2015

68. Android everywhere

69. Android closer to the web
● Instant app
● Progressive app
● Js development on android

70. Android
Potential
Maturity

71. Questions?
greg@smartsoftasia.com