Android Architecture: From Medieval to Modern

The biggest decision you need to make at the beginning of each project is which architecture to use. This lays down the foundation on which the project will be built up. You want to build fast, test faster and be able to implement each change on the fly. Is that really possible? I will tell you how we do this at Infinum. The main point is that an architecture is always evolving so should you!

Transcript

1. Android architecture: From medieval to modern IVAN MARIĆ
2. 01 ACTIVITY
3. USAGE • Display UI • User interaction • Manipulate storage • Network calls • Business logic • Track user location • Take picture • Play media
4. USAGE • Display UI • User interaction • Manipulate storage • Network calls • Business logic • Track user location • Take picture • Play media • World peace
5. GOD ACTIVITY
6. GOD ACTIVITY + FRAGMENT + EVENTBUS
7. =
8. ARCHITECTURE
10. MVC MVP CLEAN MVVM MVI …
11. INFINUM ANDROID TEAM • 10+ members (25+ now) • 10+ ongoing projects • Maintenance • Skill level: Junior - Pro
13. 02 MVP
14. MVP Model Presenter View
15. V P M Model Presenter View Activity 1 Fragment 1 CustomViews 1 Presenter 1 Presenter 1 Presenter 1 Interactor Repository Util/Manager Interface Interface
16. END RESULT • KISS Views
17. END RESULT • Keep It Simple Stupid Views • Testable Presenters • Maintainable project • Easy transition
20. 03 MVVM
21. MVVM Model ViewModel View DATA BINDING Interface Interface Interface
22. MVVM Model ViewModel View DATA BINDING Interface Interface Interface
23. private void login() { loginViewModel.loginWithToken().observe(this, withObserver( loginUserResource -> startActivityAndFinish(DashboardActivity.buildIntent(this)), throwable -> { ViewUtils.setVisibility(scanButton, View.VISIBLE); onError(throwable); }, this::onError )); }a
24. private void login() { loginViewModel.loginWithToken().observe(this, withObserver( loginUserResource -> startActivityAndFinish(DashboardActivity.buildIntent(this)), throwable -> { ViewUtils.setVisibility(scanButton, View.VISIBLE); onError(throwable); }, this::onError )); }a
25. private void login() { loginViewModel.loginWithToken().observe(this, withObserver( loginUserResource -> startActivityAndFinish(DashboardActivity.buildIntent(this)), throwable -> { ViewUtils.setVisibility(scanButton, View.VISIBLE); onError(throwable); }, this::onError )); }a
26. private void login() { loginViewModel.loginWithToken().observe(this, withObserver( loginUserResource -> startActivityAndFinish(DashboardActivity.buildIntent(this)), throwable -> { ViewUtils.setVisibility(scanButton, View.VISIBLE); onError(throwable); }, this::onError )); }a
27. private void checkForUpdates() { versionViewModel.checkForUpdates().observe(this, result -> { if (result instanceof NewUpdate) { showUpdateDialog(((NewUpdate) result).url); } else if (result instanceof NoUpdate) { login(); } else if (result instanceof Error) { showErrorDialog(); } else { Timber.wtf(new IllegalArgumentException("Impossible case")); }a }); }b
28. private void checkForUpdates() { versionViewModel.checkForUpdates().observe(this, result -> { if (result instanceof NewUpdate) { showUpdateDialog(((NewUpdate) result).url); } else if (result instanceof NoUpdate) { login(); } else if (result instanceof Error) { showErrorDialog(); } else { Timber.wtf(new IllegalArgumentException("Impossible case")); }a }); }b
29. private void checkForUpdates() { versionViewModel.checkForUpdates().observe(this, result -> { if (result instanceof NewUpdate) { showUpdateDialog(((NewUpdate) result).url); } else if (result instanceof NoUpdate) { login(); } else if (result instanceof Error) { showErrorDialog(); } else { Timber.wtf(new IllegalArgumentException("Impossible case")); }a }); }b
30. private void checkForUpdates() { versionViewModel.checkForUpdates().observe(this, result -> { if (result instanceof NewUpdate) { showUpdateDialog(((NewUpdate) result).url); } else if (result instanceof NoUpdate) { login(); } else if (result instanceof Error) { showErrorDialog(); } else { Timber.wtf(new IllegalArgumentException("Impossible case")); }a }); }b
31. private void checkForUpdates() { versionViewModel.checkForUpdates().observe(this, result -> { if (result instanceof NewUpdate) { showUpdateDialog(((NewUpdate) result).url); } else if (result instanceof NoUpdate) { login(); } else if (result instanceof Error) { showErrorDialog(); } else { Timber.wtf(new IllegalArgumentException("Impossible case")); }a }); }b
32. OBSERVERS EVERYWHERE OBSERVERS
33. 04 MVVM + MVI
34. 04 MVVM + VIEW STATE
35. MODEL VIEW INTENT • http://hannesdorfmann.com/android/mosby3-mvi-1 • Solving basic problems • Unidirectional flow • Define the real model
36. Model Presenter View Model ViewModel View
37. Model Presenter Model ViewModel View View
38. Model ViewModel View STATE GENERATOR
39. Model ViewModel View State STATE GENERATOR
40. Model ViewModel View State STATE GENERATOR
41. Model ViewModel View State STATE GENERATOR
42. viewModel.viewStateRender().observe(this, Observer { when (it) { is TwoFaNeeded -> displayCodeInput() is WrongCredentials -> showCredentialError() is LoginSuccess -> startActivity<DashboardActivity>() is OpenForgotPassword -> startActivity<ForgotPasswordFlowActivity>() }a }) VIEW
43. VIEW viewModel.viewStateRender().observe(this, Observer { when (it) { is TwoFaNeeded -> displayCodeInput() is WrongCredentials -> showCredentialError() is LoginSuccess -> startActivity<DashboardActivity>() is OpenForgotPassword -> startActivity<ForgotPasswordFlowActivity>() }a })
44. viewModel.viewStateRender().observe(this, Observer { when (it) { is TwoFaNeeded -> displayCodeInput() is WrongCredentials -> showCredentialError() is LoginSuccess -> startActivity<DashboardActivity>() is OpenForgotPassword -> startActivity<ForgotPasswordFlowActivity>() }a }) VIEW
45. viewModel.viewStateRender().observe(this, Observer { when (it) { is TwoFaNeeded -> displayCodeInput() is WrongCredentials -> showCredentialError() is LoginSuccess -> startActivity<DashboardActivity>() is OpenForgotPassword -> startActivity<ForgotPasswordFlowActivity>() }a }) VIEW
46. viewModel.viewStateRender().observe(this, Observer { when (it) { is TwoFaNeeded -> displayCodeInput() is WrongCredentials -> showCredentialError() is LoginSuccess -> startActivity<DashboardActivity>() is OpenForgotPassword -> startActivity<ForgotPasswordFlowActivity>() }a }) VIEW
47. fun action(action: LoginAction) { when (action) { is CheckCredentials -> verifyCredentials(action.username, action.password) is ForgotPassword -> viewStateLiveData.postValue(OpenForgotPassword()) }a }b ACTION
48. fun action(action: LoginAction) { when (action) { is CheckCredentials -> verifyCredentials(action.username, action.password) is ForgotPassword -> viewStateLiveData.postValue(OpenForgotPassword()) }a }b ACTION
49. fun action(action: LoginAction) { when (action) { is CheckCredentials -> verifyCredentials(action.username, action.password) is ForgotPassword -> viewStateLiveData.postValue(OpenForgotPassword()) }a }b ACTION
50. fun action(action: LoginAction) { when (action) { is CheckCredentials -> verifyCredentials(action.username, action.password) is ForgotPassword -> viewStateLiveData.postValue(OpenForgotPassword()) }a }b ACTION
51. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onSuccess(response: AuthResponse) { viewStateLiveData.postValue(LoginSuccess()) }a override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
52. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onSuccess(response: AuthResponse) { viewStateLiveData.postValue(LoginSuccess()) }a }) }d
53. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onSuccess(response: AuthResponse) { viewStateLiveData.postValue(LoginSuccess()) }a }) }d
54. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onSuccess(response: AuthResponse) { viewStateLiveData.postValue(LoginSuccess()) }aA }) }d
55. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onSuccess(response: AuthResponse) { viewStateLiveData.postValue(LoginSuccess()) }aA }) }d
56. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
57. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
58. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
59. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
60. private fun verifyCredentials(username: String, password: String) { authInteractor.execute(LoginData(user = username, password = password)) .subscribe(object : ErrorHandlingSingleObserver<AuthResponse>() { override fun onErrorResponse(error: ErrorResponse) { when (error.errorCode) { ErrorCode.UserDisabled -> commonStateLiveData.value = ErrorMessage(R.string.error_user_disabled) ErrorCode.IncorrectCredentials -> viewStateLiveData.postValue(WrongCredentials()) }b }c }) }d
61. 05 KOTLIN MAKES A DIFFERENCE
62. sealed class LoadingState sealed class ErrorState data class CommonState(a val loadingState: LoadingState, val errorState: ErrorState )b open class ViewState<State>(c var viewState: State? = null, var commonState: CommonState = IDLE_STATE )d
63. sealed class LoadingState sealed class ErrorState data class CommonState(a val loadingState: LoadingState, val errorState: ErrorState )b open class ViewState<State>(c var viewState: State? = null, var commonState: CommonState = IDLE_STATE )d
64. sealed class LoadingState sealed class ErrorState data class CommonState(a val loadingState: LoadingState, val errorState: ErrorState )b open class ViewState<State>(c var viewState: State? = null, var commonState: CommonState = IDLE_STATE )d
65. sealed class LoadingState sealed class ErrorState data class CommonState(a val loadingState: LoadingState, val errorState: ErrorState )b open class ViewState<State>(c var viewState: State? = null, var commonState: CommonState = IDLE_STATE )d
66. sealed class LoadingState sealed class ErrorState data class CommonState(a val loadingState: LoadingState, val errorState: ErrorState )b open class ViewState<State>(c var viewState: State? = null, var commonState: CommonState = IDLE_STATE )d
67. protected var viewState: State? = null get() = mutableLiveData.value?.viewState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(viewState = value)) } else { mutableLiveData.value?.viewState = value mutableLiveData.post() }a }b
68. protected var viewState: State? = null get() = mutableLiveData.value?.viewState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(viewState = value)) } else { mutableLiveData.value?.viewState = value mutableLiveData.post() }a }b
69. protected var viewState: State? = null get() = mutableLiveData.value?.viewState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(viewState = value)) } else { mutableLiveData.value?.viewState = value mutableLiveData.post() }a }b
70. protected var commonState: CommonState = IDLE_STATE get() = mutableLiveData.value?.commonState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(commonState = value)) } else { mutableLiveData.value?.commonState = value mutableLiveData.post() } }
71. protected var commonState: CommonState = IDLE_STATE get() = mutableLiveData.value?.commonState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(commonState = value)) } else { mutableLiveData.value?.commonState = value mutableLiveData.post() } }
72. protected var commonState: CommonState = IDLE_STATE get() = mutableLiveData.value?.commonState ?: field set(value) { val viewState = mutableLiveData.value if (viewState == null) { mutableLiveData.postValue(ViewState(commonState = value)) } else { mutableLiveData.value?.commonState = value mutableLiveData.post() } }
73. fun <State> LiveData<ViewState<State>>.render(baseActivity: BaseActivity, action: (State) -> Unit) { observe(baseActivity, ViewModelObserver(baseActivity, action)) } class ViewModelObserver<T>(val baseActivity: RenderComponent, val action: (T) -> Unit) : Observer<ViewState<T>> { private var lastState: T? = null private var lastCommonState: CommonState? = null override fun onChanged(t: ViewState<T>?) { if (t == null) { Timber.e("LiveData.value is [NULL]") return } val state = t.viewState if (t.commonState != lastCommonState) { baseActivity.handleBaseState(t.commonState) lastCommonState = t.commonState } if (state != null && state != lastState) { lastState = state action(state) } } }
74. fun <State> LiveData<ViewState<State>>.render(baseActivity: BaseActivity, action: (State) -> Unit) { observe(baseActivity, ViewModelObserver(baseActivity, action)) } class ViewModelObserver<T>(val baseActivity: RenderComponent, val action: (T) -> Unit) : Observer<ViewState<T>> { private var lastState: T? = null private var lastCommonState: CommonState? = null override fun onChanged(t: ViewState<T>?) { if (t == null) { Timber.e("LiveData.value is [NULL]") return } val state = t.viewState if (t.commonState != lastCommonState) { baseActivity.handleBaseState(t.commonState) lastCommonState = t.commonState } if (state != null && state != lastState) { lastState = state action(state) } } }
75. fun <State> LiveData<ViewState<State>>.render(baseActivity: BaseActivity, action: (State) -> Unit) { observe(baseActivity, ViewModelObserver(baseActivity, action)) } class ViewModelObserver<T>(val baseActivity: RenderComponent, val action: (T) -> Unit) : Observer<ViewState<T>> { private var lastState: T? = null private var lastCommonState: CommonState? = null override fun onChanged(t: ViewState<T>?) { if (t == null) { Timber.e("LiveData.value is [NULL]") return } val state = t.viewState if (t.commonState != lastCommonState) { baseActivity.handleBaseState(t.commonState) lastCommonState = t.commonState } if (state != null && state != lastState) { lastState = state action(state) } } }
76. fun <State> LiveData<ViewState<State>>.render(baseActivity: BaseActivity, action: (State) -> Unit) { observe(baseActivity, ViewModelObserver(baseActivity, action)) } class ViewModelObserver<T>(val baseActivity: RenderComponent, val action: (T) -> Unit) : Observer<ViewState<T>> { private var lastState: T? = null private var lastCommonState: CommonState? = null override fun onChanged(t: ViewState<T>?) { if (t == null) { Timber.e("LiveData.value is [NULL]") return } val state = t.viewState if (t.commonState != lastCommonState) { baseActivity.handleBaseState(t.commonState) lastCommonState = t.commonState } if (state != null && state != lastState) { lastState = state action(state) } } }
77. 06 COMPARISON
78. MVP VS MVVM interface LoginView : BaseMvp.View { fun updatesFound(String version) fun loginSuccess() } sealed class LoginState class LoginUpdatesFound(val version: String) : LoginState() class LoginSuccess : LoginState()
79. MVP VS MVVM class BaseMvp { interface View { fun showProgress() fun hideProgress() fun showError(title: String, message: String) } } sealed class CommonState class CommonLoading() : CommonState() class CommonIdle : CommonState() class CommonError(val title: String, val message: String) : CommonState()
80. Presenter View ViewModel View MVP VS MVVM REFERENCE AND DIRECT CALLS LIVE DATA AND OBSERVER
81. Presenter View ViewModel View MVP VS MVVM LIFECYCLE METHODS LIVE DATA
82. 07 ADVANTAGES
83. LIFECYCLE • Live data lifecycle aware • observe(lifecycleOwner, Observer{ })
84. LIFECYCLE • Live data lifecycle aware • observe(lifecycleOwner, Observer{ }) • Right time notifications
85. NETWORK CALL • Cancel callback
86. NETWORK CALL • Cancel callback • State changed without notification
87. NETWORK CALL • Cancel callback • State changed without notification • Latest known state rendered
88. ORIENTATION CHANGE • ViewModel is not destroyed
89. ORIENTATION CHANGE • ViewModel is not destroyed • State preserved without SaveInstance
90. ORIENTATION CHANGE • ViewModel is not destroyed • State preserved without SaveInstance • Latest known state rendered
91. FRAGMENT COMMUNICATION ACTIVITY FRAGMENT Your name please
92. FRAGMENT COMMUNICATION ACTIVITY FRAGMENT Your name please VIEW MODEL
93. FRAGMENT COMMUNICATION ACTIVITY FRAGMENT Ivan VIEW MODEL input(“Ivan”) liveData.value = “Ivan” Hi, Ivan!
94. FRAGMENT COMMUNICATION ACTIVITY FRAGMENT FRAGMENT FRAGMENT FRAGMENT Ivan ivan.maric@infinum.hr Infinum { "name":"Ivan", "mail":"ivan.maric@infinum.hr", "company":"Infinum" }
95. Visit infinum.co or find us on social networks: infinum.co infinumco infinumco infinum Thank you! IVAN.MARIC@INFINUM.HR @MARIC_IV