Add base presenter and alternative disposable observer

app/src/androidTest/kotlin/com/fernandocejas/sample/AcceptanceTest.kt

@@ -13,7 +13,7 @@ import org.junit.runner.RunWith
 abstract class AcceptanceTest<T : Activity>(clazz: Class<T>) {
 
     @Rule @JvmField
-    val testRule: ActivityTestRule<T> = IntentsTestRule(clazz)
+    val testRule = IntentsTestRule(clazz)
 
     val checkThat: Matchers = Matchers()
     val events: Events = Events()

app/src/main/kotlin/com/fernandocejas/sample/BaseFragment.kt

@@ -5,8 +5,9 @@ import android.support.v4.app.Fragment
 import android.view.LayoutInflater
 import android.view.ViewGroup
 import com.fernandocejas.sample.di.ApplicationComponent
+import com.fernandocejas.sample.features.base.BaseView
 
-abstract class BaseFragment : Fragment() {
+abstract class BaseFragment : Fragment(), BaseView {
     init {
         retainInstance = true
     }
@@ -19,4 +20,20 @@ abstract class BaseFragment : Fragment() {
 
     override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?) =
             inflater?.inflate(layoutId(), container, false)
+
+    override fun showLoading() {
+        //TODO: implement method
+    }
+
+    override fun hideLoading() {
+        //TODO: implement method
+    }
+
+    override fun showError(e: Throwable) {
+        TODO("not implemented")
+    }
+
+    override fun dispose() {
+        //TODO: implement method
+    }
 }

app/src/main/kotlin/com/fernandocejas/sample/features/base/BasePresenter.kt

@@ -0,0 +1,28 @@
+package com.fernandocejas.sample.features.base
+
+abstract class BasePresenter<V : BaseView> : Presenter<V>() {
+
+    override fun disposeView() = view.dispose()
+
+    override fun dropView() = super.dropView()
+
+    override fun takeView(view: V) = super.takeView(view)
+
+    fun initialize(view: V) {
+        takeView(view)
+        view.hideLoading()
+    }
+
+    fun finalize() = dropView()
+
+    open fun onComplete() = onCompleteBase()
+    open fun onNext(response: Any) = onNextBase(response)
+    open fun onError(e: Throwable) = onErrorBase(e)
+
+    private fun onCompleteBase() = view.hideLoading()
+    private fun onNextBase(response: Any) = view.hideLoading()
+    private fun onErrorBase(e: Throwable) = view.apply {
+        hideLoading()
+        showError(e)
+    }
+}

app/src/main/kotlin/com/fernandocejas/sample/features/base/BaseView.kt

@@ -0,0 +1,8 @@
+package com.fernandocejas.sample.features.base
+
+interface BaseView {
+    fun showLoading()
+    fun hideLoading()
+    fun showError(e: Throwable)
+    fun dispose()
+}

app/src/main/kotlin/com/fernandocejas/sample/features/base/Presenter.kt

@@ -0,0 +1,52 @@
+package com.fernandocejas.sample.features.base
+
+abstract class Presenter<View> {
+
+    /**
+     * Returns a current view attached to the presenter.
+     *
+     * @return a current attached view.
+     */
+    abstract var view: View
+
+    /**
+     * This method is being called when a view gets attached to it.
+     *
+     * This method is intended for overriding.
+     *
+     * @param view a view that should be taken.
+     */
+    protected open fun onTakeView(view: View) {
+    }
+
+    /**
+     * This method is being called when a view gets detached from the presenter.
+     *
+     * This method is intended for overriding.
+     */
+    protected open fun onDropView() {
+    }
+
+    /**
+     * Attaches a view to the presenter.
+     *
+     * @param view a view to attach.
+     */
+    open fun takeView(view: View) {
+        this.view = view
+        onTakeView(view)
+    }
+
+    /**
+     * Detaches the presenter from a view.
+     */
+    open fun dropView() {
+        onDropView()
+        disposeView()
+    }
+
+    /**
+     * Dispose a view.
+     */
+    abstract fun disposeView()
+}

app/src/main/kotlin/com/fernandocejas/sample/features/movies/MoviesFragment.kt

@@ -13,9 +13,7 @@ class MoviesFragment : BaseFragment(), MoviesView {
     @Inject lateinit var moviesPresenter: MoviesPresenter
     @Inject lateinit var moviesAdapter: MoviesAdapter
 
-    override fun layoutId(): Int {
-        return R.layout.fragment_movies
-    }
+    override fun layoutId(): Int = R.layout.fragment_movies
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -29,8 +27,8 @@ class MoviesFragment : BaseFragment(), MoviesView {
     }
 
     override fun onDestroy() {
-        super.onDestroy()
         moviesPresenter.destroy()
+        super.onDestroy()
     }
 
     override fun renderList(movies: List<MovieViewModel>) {
@@ -41,22 +39,10 @@ class MoviesFragment : BaseFragment(), MoviesView {
         TODO()
     }
 
-    override fun showLoading() {
-        //TODO: implement method
-    }
-
-    override fun hideLoading() {
-        //TODO: implement method
-    }
-
-    override fun dispose() {
-        //TODO: dispose view resources
-    }
-
     private fun initializeView() {
         rv_movies.layoutManager = LinearLayoutManager(this.activity.application)
         rv_movies.adapter = moviesAdapter
-        moviesPresenter.moviesView = this
+        moviesPresenter.initialize(this)
     }
 
     private fun loadMovies() {

app/src/main/kotlin/com/fernandocejas/sample/features/movies/MoviesPresenter.kt

@@ -1,26 +1,26 @@
 package com.fernandocejas.sample.features.movies
 
-import com.fernandocejas.sample.framework.interactor.UseCaseObserver
+import com.fernandocejas.sample.features.base.BasePresenter
+import com.fernandocejas.sample.framework.interactor.UsecaseDisposableObserver
 import javax.inject.Inject
 
 class MoviesPresenter
-@Inject constructor(private val getMovies: GetMovies) {
+@Inject constructor(private val getMovies: GetMovies) : BasePresenter<MoviesView>() {
 
-    internal lateinit var moviesView: MoviesView
+    override lateinit var view: MoviesView
 
     fun destroy() {
         getMovies.dispose()
-        moviesView.dispose()
+        finalize()
     }
 
     fun loadMovies() {
-        moviesView.showLoading()
-        getMovies.execute(MoviesObserver())
+        view.showLoading()
+        getMovies.execute(UsecaseDisposableObserver(
+                { onComplete() },
+                { onGetMoviesNext(it) },
+                { onError(it) }))
     }
 
-    private inner class MoviesObserver : UseCaseObserver<List<Movie>>() {
-        override fun onComplete() = moviesView.hideLoading()
-        override fun onNext(value: List<Movie>) = moviesView.renderList(value.map(::MovieViewModel))
-        override fun onError(e: Throwable) = TODO()
-    }
+    fun onGetMoviesNext(value: List<Movie>) = view.renderList(value.map(::MovieViewModel))
 }

app/src/main/kotlin/com/fernandocejas/sample/features/movies/MoviesView.kt

@@ -5,5 +5,4 @@ import com.fernandocejas.sample.framework.view.LoadingView
 interface MoviesView : LoadingView {
     fun renderList(movies: List<MovieViewModel>)
     fun displayDetails(movie: MovieViewModel)
-    fun dispose()
 }

app/src/main/kotlin/com/fernandocejas/sample/framework/interactor/UseCase.kt

@@ -3,6 +3,7 @@ package com.fernandocejas.sample.framework.interactor
 import com.fernandocejas.sample.framework.executor.ExecutionScheduler
 import io.reactivex.Observable
 import io.reactivex.disposables.CompositeDisposable
+import io.reactivex.observers.DisposableObserver
 import javax.inject.Inject
 
 abstract class UseCase<T, in P> where P : Any {
@@ -11,7 +12,7 @@ abstract class UseCase<T, in P> where P : Any {
 
     abstract fun buildObservable(params: P?): Observable<T>
 
-    fun execute(observer: UseCaseObserver<T>, params: P? = null) {
+    fun execute(observer: DisposableObserver<T>, params: P? = null) {
         disposables
                 .add(buildObservable(params)
                 .subscribeWith(observer))

app/src/main/kotlin/com/fernandocejas/sample/framework/interactor/UsecaseDisposableObserver.kt

@@ -0,0 +1,14 @@
+package com.fernandocejas.sample.framework.interactor
+
+import io.reactivex.observers.DisposableObserver
+
+open class UsecaseDisposableObserver<T>(
+        private val onUseCaseComplete: () -> Unit = { },
+        private val onUseCaseNext: (T) -> Unit = { },
+        private val onUseCaseError: (Throwable) -> Unit = { })
+    : DisposableObserver<T>() {
+
+    override fun onComplete() = onUseCaseComplete()
+    override fun onNext(response: T) = onUseCaseNext(response)
+    override fun onError(e: Throwable) = onUseCaseError(e)
+}

app/src/main/kotlin/com/fernandocejas/sample/framework/view/LoadingView.kt

@@ -1,6 +1,5 @@
 package com.fernandocejas.sample.framework.view
 
-interface LoadingView {
-    fun showLoading()
-    fun hideLoading()
-}
+import com.fernandocejas.sample.features.base.BaseView
+
+interface LoadingView : BaseView