ROSIE: CLEAN USE CASE FRAMEWORK

During the past years we have been discussing and iterating over our mobile application architecture at Karumi, and the result of all that work is called Rosie.

Rosie is a framework that helps application development by focusing on three pillars that we consider very important: testability, code scalability y code readability.

This talk is not about promoting Rosie but rather the creation process of this framework, the needs that we needed to cover and how we materialized all the literature present in tons of books and internet articles. This is about problems and solutions

Transcript

1. ROSIE: CLEAN USE CASE FRAMEWORK Jorge Juan Barroso Carmona jorge@karumi.com @flipper83 +JorgeJBarroso Pedro Gomez Sergio Gutierrez
2. Basho. Poet Karumi is the beauty of ordinary things spoken of in a simple way.
3. Sergio Gutierrez Senior Mobile Engineer Pedro Gomez Senior Mobile Engineer Alberto Gragera Technical Director Davide Mendolia Senior Full Stack Engineer
4. Adam Tornhill “If Clean Architecture is about running away from frameworks, does a clean architecture framework make sense?”
5. Adam Tornhill https://github.com/Karumi/Rosie
6. Why
7. We Start a New Project every three Months
8. Remove boilerplate code
9. Easy to change and evolve
10. Testable
11. Open Source
12. Activity Fragment Service View … Presenter View Use Case Rich Model Repository DataSource Api Retrofit SharedPref Api Sync Execution
13. UI Layer
14. divide ui framework from ui logic
15. improve UI Testing
16. Activity Fragment Service View … Presenter View Domain Model Presentation Model Use Case
17. Adam Tornhill public class SampleActivity extends RosieActivity implements SamplePresenter.View { @Inject @Presenter SamplePresenter presenter; @Override protected void onPreparePresenter() {/*...*/} }
18. Adam Tornhill public class SampleActivity extends RosieActivity implements SamplePresenter.View { @Inject @Presenter SamplePresenter presenter; @Override protected void onPreparePresenter() {/*...*/} }
19. Adam Tornhill public class SampleActivity extends RosieActivity implements SamplePresenter.View { @Inject @Presenter SamplePresenter presenter; @Override protected void onPreparePresenter() {/*...*/} }
20. Adam Tornhill public class SamplePresenter extends RosiePresenter<SamplePresenter.View> { protected void initialize() {/*...*/} protected void update() {/*...*/} protected void pause() {/*...*/} protected void destroy() {/*...*/} private void sampleMethod() { View view = getView(); // Get the view linked to the presenter view.foo(); } public interface View extends RosiePresenter.View { void foo(); }
21. Adam Tornhill public class SamplePresenter extends RosiePresenter<SamplePresenter.View> { protected void initialize() {/*...*/} protected void update() {/*...*/} protected void pause() {/*...*/} protected void destroy() {/*...*/} private void sampleMethod() { View view = getView(); // Get the view linked to the presenter view.foo(); } public interface View extends RosiePresenter.View { void foo(); }
22. Adam Tornhill public class SamplePresenter extends RosiePresenter<SamplePresenter.View> { protected void initialize() {/*...*/} protected void update() {/*...*/} protected void pause() {/*...*/} protected void destroy() {/*...*/} private void sampleMethod() { View view = getView(); // Get the view linked to the presenter view.foo(); } public interface View extends RosiePresenter.View { void foo(); }
23. Adam Tornhill public class SamplePresenter extends RosiePresenter<SamplePresenter.View> { protected void initialize() {/*...*/} protected void update() {/*...*/} protected void pause() {/*...*/} protected void destroy() {/*...*/} private void sampleMethod() { View view = getView(); // Get the view linked to the presenter view.foo(); } public interface View extends RosiePresenter.View { void foo(); }
24. we need extract common code
25. Adam Tornhill public final class PresenterLifeCycleLinker { public void initializeLifeCycle(Object source, RosiePresenter.View view) {
 if (source == null) {
 throw new IllegalArgumentException(
 "The source instance used to initialize the presenters can't be null");
 }
 if (view == null) {
 throw new IllegalArgumentException(
 "The view instance used to initialize the presenters can't be null");
 }
 
 addAnnotatedPresenter(source);
 setView(view);
 initializePresenters();
 }
26. Adam Tornhill public final class PresenterLifeCycleLinker { public void initializeLifeCycle(Object source, RosiePresenter.View view) {
 if (source == null) {
 throw new IllegalArgumentException(
 "The source instance used to initialize the presenters can't be null");
 }
 if (view == null) {
 throw new IllegalArgumentException(
 "The view instance used to initialize the presenters can't be null");
 }
 
 addAnnotatedPresenter(source);
 setView(view);
 initializePresenters();
 }
27. avoid NullPointers
28. Adam Tornhill void resetView() {
 final Class<?> viewClass = getViewInterfaceClass();
 InvocationHandler emptyHandler = new InvocationHandler() {
 @Override
 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 return null;
 }
 };
 ClassLoader classLoader = viewClass.getClassLoader();
 Class[] interfaces = new Class[1];
 interfaces[0] = viewClass;
 this.view = (T) Proxy.newProxyInstance(classLoader, interfaces, emptyHandler); }
29. Adam Tornhill void resetView() {
 final Class<?> viewClass = getViewInterfaceClass();
 InvocationHandler emptyHandler = new InvocationHandler() {
 @Override
 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 return null;
 }
 };
 ClassLoader classLoader = viewClass.getClassLoader();
 Class[] interfaces = new Class[1];
 interfaces[0] = viewClass;
 this.view = (T) Proxy.newProxyInstance(classLoader, interfaces, emptyHandler); }
30. Adam Tornhill void resetView() {
 final Class<?> viewClass = getViewInterfaceClass();
 InvocationHandler emptyHandler = new InvocationHandler() {
 @Override
 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 return null;
 }
 };
 ClassLoader classLoader = viewClass.getClassLoader();
 Class[] interfaces = new Class[1];
 interfaces[0] = viewClass;
 this.view = (T) Proxy.newProxyInstance(classLoader, interfaces, emptyHandler); }
31. Domain Layer
32. Use cases define operations over our software
33. Domain Model (Inmutable please) Domain Model Use Case Rich Model Domain Model
34. Adam Tornhill public class ComicsPresenter extends RosiePresenter<ComicsPresenter.View> { public void getComics() { createUseCaseCall(getComics) .args(superHeroId, authorId) .onSuccess(new OnSuccessCallback() { /*...*/ }) .onError(new OnErrorCallback() { /*...*/ }) .execute(); }
35. Adam Tornhill public class ComicsPresenter extends RosiePresenter<ComicsPresenter.View> { public void getComics() { createUseCaseCall(getComics) .args(superHeroId, authorId) .name(“sortByDate”) .onSuccess(new OnSuccessCallback() { /*...*/ }) .onError(new OnErrorCallback() { /*...*/ }) .execute(); }
36. Adam Tornhill public class ComicsPresenter extends RosiePresenter<ComicsPresenter.View> { public void getComics() { createUseCaseCall(getComics) .args(superHeroId, authorId) .name(“sortByDate”) .onSuccess(new OnSuccessCallback() { /*...*/ }) .onError(new OnErrorCallback() { /*...*/ }) .execute(); }
37. Adam Tornhill public class ComicsPresenter extends RosiePresenter<SamplePresenter.View> { public void getComics() { createUseCaseCall(getComics) .args(superHeroId, authorId) .name(“sortByDate”) .onSuccess(new OnSuccessCallback() { /*...*/ }) .onError(new OnErrorCallback() { /*...*/ }) .execute(); }
38. Adam Tornhill public class GetComics extends RosieUseCase { @UseCase (name = “sortByDate”) public void getComicsSortedByDate(String superHeroId, String authorId) { try { Comics comics = getComics(superHeroId, authorId); notifySuccess(comics.getSortedByDate()); } catch (DataException e) { notifyError(generateDataError(e)); } } }
39. Adam Tornhill public class GetComics extends RosieUseCase { @UseCase (name = “sortByDate”) public void getComicsSortedByDate(String superHeroId, String authorId) { try { Comics comics = getComics(superHeroId, authorId); notifySuccess(comics.getSortedByDate()); } catch (DataException e) { notifyError(generateDataError(e)); } } }
40. Adam Tornhill public class GetComics extends RosieUseCase { @UseCase (name = “sortByDate”) public void getComicsSortedByDate(String superHeroId, String authorId) { try { Comics comics = getComics(superHeroId, authorId); notifySuccess(comics.getSortedByDate()); } catch (DataException e) { notifyError(generateDataError(e)); } } }
41. Adam Tornhill public class GetComics extends RosieUseCase { @UseCase (name = “sortByDate”) public void getComicsSortedByDate(String superHeroId, String authorId) { try { Comics comics = getComics(superHeroId, authorId); notifySuccess(comics.getSortedByDate()); } catch (DataException e) { notifyError(generateDataError(e)); } } }
42. Use cases are async
43. Adam Tornhill public class UseCaseHandler {
 
 private final TaskScheduler taskScheduler;
 private final ErrorHandler errorHandler;
 
 public UseCaseHandler(TaskScheduler taskScheduler, ErrorHandler errorHandler) {
 this.taskScheduler = taskScheduler;
 this.errorHandler = errorHandler;
 }
44. Adam Tornhill public class UseCaseHandler {
 
 private final TaskScheduler taskScheduler;
 private final ErrorHandler errorHandler;
 
 public UseCaseHandler(TaskScheduler taskScheduler, ErrorHandler errorHandler) {
 this.taskScheduler = taskScheduler;
 this.errorHandler = errorHandler;
 }
45. Adam Tornhill public class UseCaseHandler {
 
 private final TaskScheduler taskScheduler;
 private final ErrorHandler errorHandler;
 
 public UseCaseHandler(TaskScheduler taskScheduler, ErrorHandler errorHandler) {
 this.taskScheduler = taskScheduler;
 this.errorHandler = errorHandler;
 }
46. Adam Tornhill public interface TaskScheduler {
 void execute(UseCaseWrapper useCaseWrapper);
 } public class TaskSchedulerJobQueue implements TaskScheduler {
 private final JobManager jobManager;
 
 /**/
 
 @Override public void execute(UseCaseWrapper useCaseWrapper) {
 UseCaseWrapperJob useCaseWrapperJob = new UseCaseWrapperJob(useCaseWrapper);
 jobManager.addJobInBackground(useCaseWrapperJob);
 }
 }
47. Adam Tornhill public interface TaskScheduler {
 void execute(UseCaseWrapper useCaseWrapper);
 } public class TaskSchedulerJobQueue implements TaskScheduler {
 private final JobManager jobManager;
 
 /**/
 
 @Override public void execute(UseCaseWrapper useCaseWrapper) {
 UseCaseWrapperJob useCaseWrapperJob = new UseCaseWrapperJob(useCaseWrapper);
 jobManager.addJobInBackground(useCaseWrapperJob);
 }
 }
48. Adam Tornhill public interface TaskScheduler {
 void execute(UseCaseWrapper useCaseWrapper);
 } public class TaskSchedulerJobQueue implements TaskScheduler {
 private final JobManager jobManager;
 
 /**/
 
 @Override public void execute(UseCaseWrapper useCaseWrapper) {
 UseCaseWrapperJob useCaseWrapperJob = new UseCaseWrapperJob(useCaseWrapper);
 jobManager.addJobInBackground(useCaseWrapperJob);
 }
 }
49. avoid memory leaks
50. Adam Tornhill protected final UseCaseCall createUseCaseCall(RosieUseCase useCase) {
 UseCaseCall useCaseCall = new UseCaseCall(useCase, useCaseHandler);
 retainUseCaseCall(useCaseCall);
 return useCaseCall;
 }
51. Adam Tornhill protected final UseCaseCall createUseCaseCall(RosieUseCase useCase) {
 UseCaseCall useCaseCall = new UseCaseCall(useCase, useCaseHandler);
 retainUseCaseCall(useCaseCall);
 return useCaseCall;
 }
52. Adam Tornhill final class UseCaseParams {
 
 private final String useCaseName;
 private final Object[] args;
 private WeakReference<OnSuccessCallback> onSuccessCallback;
 private WeakReference<OnErrorCallback> onErrorCallback; /**/ }
53. Adam Tornhill final class UseCaseParams {
 
 private final String useCaseName;
 private final Object[] args;
 private WeakReference<OnSuccessCallback> onSuccessCallback;
 private WeakReference<OnErrorCallback> onErrorCallback; /**/ }
54. Data layer
55. Be agnostic from Data origin
56. Be agnostic from Data origin
57. Repository DataSource Api Retrofit Api Model Mapper Domain Model Cache level DataSource Realm Realm Realm Model Mapper Use case/ rich model Populator
58. Adam Tornhill public class SampleRepository extends RosieRepository<Key, Value> { @Inject public SampleRepository(SampleApiDataSource sampleApiDataSource, SampleCacheDataSource sampleCacheDataSource) { addReadableDataSources(sampleApiDataSource); addCacheDataSources(sampleCacheDataSource); } }
59. Adam Tornhill public class SampleRepository extends RosieRepository<Key, Value> { @Inject public SampleRepository(SampleApiDataSource sampleApiDataSource, SampleCacheDataSource sampleCacheDataSource) { addReadableDataSources(sampleApiDataSource); addCacheDataSources(sampleCacheDataSource); } }
60. Adam Tornhill public class SampleRepository extends RosieRepository<Key, Value> { @Inject public SampleRepository(SampleApiDataSource sampleApiDataSource, SampleCacheDataSource sampleCacheDataSource) { addReadableDataSources(sampleApiDataSource); addCacheDataSources(sampleCacheDataSource); } }
61. Adam Tornhill public class SampleRepository extends RosieRepository<Key, Value> { @Inject public SampleRepository() { PaginatedCacheDataSource<Key, Value> inMemoryCacheDataSource = new InMemoryCacheDataSource<>(new TimeProvider(), MINUTES.toMillis(5)); addCacheDataSources(inMemoryCacheDataSource); } }
62. Adam Tornhill Key key = /*…*/; Value value; Collection<Value> values; RosieRepository<Key, Value> repository = /*...*/; value = repository.getByKey(key); value = repository.getByKey(key, ReadPolicy.CACHE_ONLY); values = repository.getAll(); values = repository.getAll(ReadPolicy.READABLE_ONLY); repository.addOrUpdate(value); repository.addOrUpdate(value, WritePolicy.WRITE_ONCE); repository.deleteByKey(key); repository.deleteAll();
63. Adam Tornhill Key key = /*…*/; Value value; Collection<Value> values; RosieRepository<Key, Value> repository = /*...*/; value = repository.getByKey(key); value = repository.getByKey(key, ReadPolicy.CACHE_ONLY); values = repository.getAll(); values = repository.getAll(ReadPolicy.READABLE_ONLY); repository.addOrUpdate(value); repository.addOrUpdate(value, WritePolicy.WRITE_ONCE); repository.deleteByKey(key); repository.deleteAll();
64. Adam Tornhill Key key = /*…*/; Value value; Collection<Value> values; RosieRepository<Key, Value> repository = /*...*/; value = repository.getByKey(key); value = repository.getByKey(key, ReadPolicy.CACHE_ONLY); values = repository.getAll(); values = repository.getAll(ReadPolicy.READABLE_ONLY); repository.addOrUpdate(value); repository.addOrUpdate(value, WritePolicy.WRITE_ONCE); repository.deleteByKey(key); repository.deleteAll();
65. Adam Tornhill Key key = /*…*/; Value value; Collection<Value> values; RosieRepository<Key, Value> repository = /*...*/; value = repository.getByKey(key); value = repository.getByKey(key, ReadPolicy.CACHE_ONLY); values = repository.getAll(); values = repository.getAll(ReadPolicy.READABLE_ONLY); repository.addOrUpdate(value); repository.addOrUpdate(value, WritePolicy.WRITE_ONCE); repository.deleteByKey(key); repository.deleteAll();
66. Repository DataSource Api Retrofit Api Model Mapper Domain Model Cache level DataSource Realm Realm Realm Model Mapper Use case/ rich model Populator
67. Adam Tornhill public class InMemoryCacheDataSource<K, V extends Identifiable<K>> implements CacheDataSource<K, V> { protected final TimeProvider timeProvider; protected final long ttlInMillis; protected final Map<K, V> items; protected long lastItemsUpdate; public InMemoryCacheDataSource(TimeProvider timeProvider, long ttlInMillis) { this.timeProvider = timeProvider; this.ttlInMillis = ttlInMillis; this.items = new LinkedHashMap<>(); } @Override public synchronized V getByKey(K key) { return items.get(key); } @Override public synchronized Collection<V> getAll() { return new ArrayList<>(items.values()); }
68. Adam Tornhill public class InMemoryCacheDataSource<K, V extends Identifiable<K>> implements CacheDataSource<K, V> { protected final TimeProvider timeProvider; protected final long ttlInMillis; protected final Map<K, V> items; protected long lastItemsUpdate; public InMemoryCacheDataSource(TimeProvider timeProvider, long ttlInMillis) { this.timeProvider = timeProvider; this.ttlInMillis = ttlInMillis; this.items = new LinkedHashMap<>(); } @Override public synchronized V getByKey(K key) { return items.get(key); } @Override public synchronized Collection<V> getAll() { return new ArrayList<>(items.values()); }
69. Adam Tornhill public class InMemoryCacheDataSource<K, V extends Identifiable<K>> implements CacheDataSource<K, V> { protected final TimeProvider timeProvider; protected final long ttlInMillis; protected final Map<K, V> items; protected long lastItemsUpdate; public InMemoryCacheDataSource(TimeProvider timeProvider, long ttlInMillis) { this.timeProvider = timeProvider; this.ttlInMillis = ttlInMillis; this.items = new LinkedHashMap<>(); } @Override public synchronized V getByKey(K key) { return items.get(key); } @Override public synchronized Collection<V> getAll() { return new ArrayList<>(items.values()); }
70. works with Cache Levels and Populate Data
71. Adam Tornhill public Collection<V> getAll(ReadPolicy policy) throws Exception {
 Collection<V> values = null;
 
 if (policy.useCache()) {
 values = getValuesFromCaches();
 }
 
 if (values == null && policy.useReadable()) {
 values = getValuesFromReadables();
 }
 
 if (values != null) {
 populateCaches(values);
 }
 
 return values;
 }
72. Adam Tornhill public Collection<V> getAll(ReadPolicy policy) throws Exception {
 Collection<V> values = null;
 
 if (policy.useCache()) {
 values = getValuesFromCaches();
 }
 
 if (values == null && policy.useReadable()) {
 values = getValuesFromReadables();
 }
 
 if (values != null) {
 populateCaches(values);
 }
 
 return values;
 }
73. Adam Tornhill private Collection<V> getValuesFromCaches() throws Exception {
 Collection<V> values = null;
 
 for (CacheDataSource<K, V> cacheDataSource : cacheDataSources) {
 values = cacheDataSource.getAll();
 
 if (values != null) {
 if (areValidValues(values, cacheDataSource)) {
 break;
 } else {
 cacheDataSource.deleteAll();
 values = null;
 }
 }
 }
 
 return values;
 }
74. Adam Tornhill private Collection<V> getValuesFromCaches() throws Exception {
 Collection<V> values = null;
 
 for (CacheDataSource<K, V> cacheDataSource : cacheDataSources) {
 values = cacheDataSource.getAll();
 
 if (values != null) {
 if (areValidValues(values, cacheDataSource)) {
 break;
 } else {
 cacheDataSource.deleteAll();
 values = null;
 }
 }
 }
 
 return values;
 }
75. Adam Tornhill public Collection<V> getAll(ReadPolicy policy) throws Exception {
 Collection<V> values = null;
 
 if (policy.useCache()) {
 values = getValuesFromCaches();
 }
 
 if (values == null && policy.useReadable()) {
 values = getValuesFromReadables();
 }
 
 if (values != null) {
 populateCaches(values);
 }
 
 return values;
 }
76. Adam Tornhill public Collection<V> getAll(ReadPolicy policy) throws Exception {
 Collection<V> values = null;
 
 if (policy.useCache()) {
 values = getValuesFromCaches();
 }
 
 if (values == null && policy.useReadable()) {
 values = getValuesFromReadables();
 }
 
 if (values != null) {
 populateCaches(values);
 }
 
 return values;
 }
77. protected void populateCaches(Collection<V> values) throws Exception {
 for (CacheDataSource<K, V> cacheDataSource : cacheDataSources) {
 cacheDataSource.addOrUpdateAll(values);
 }
 }
78. Conclusions
79. This is not a Silver bullet
80. Easy to write New Features
81. Thought for new Projects
82. Forget Concurrency
83. Ready to write Test and Mock
84. It is open source. do you want to Contribute?
85. Find me I am very social! jorge@karumi.com @flipper83 +JorgeJBarroso Questions?