Farsiyan V. Flow

flowcats/build.gradle

@@ -45,5 +45,6 @@ dependencies {
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.4.3'
     implementation 'androidx.activity:activity-ktx:1.2.3'
     testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.4.3'
-    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1'
+    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.5.1'
+    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.6.0-alpha02'
 }

flowcats/src/main/java/otus/homework/flowcats/CatsViewModel.kt

@@ -2,6 +2,8 @@ package otus.homework.flowcats
 
 import androidx.lifecycle.*
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -13,11 +15,20 @@ class CatsViewModel(
     private val _catsLiveData = MutableLiveData<Fact>()
     val catsLiveData: LiveData<Fact> = _catsLiveData
 
+    private val _catsStateFlow = MutableStateFlow<Result<Fact>>(Result.Success(null))
+    val catsStateFlow: StateFlow<Result<Fact>> = _catsStateFlow
+
     init {
         viewModelScope.launch {
             withContext(Dispatchers.IO) {
-                catsRepository.listenForCatFacts().collect {
-                    _catsLiveData.value = it
+                try {
+                    catsRepository.listenForCatFacts().collect {
+                        _catsStateFlow.value = Result.Success(it)
+                    }
+                } catch (e: Exception) {
+                    catsRepository.listenForCatFacts().collect {
+                        _catsStateFlow.value = Result.Error(it)
+                    }
                 }
             }
         }
@@ -26,6 +37,7 @@ class CatsViewModel(
 
 class CatsViewModelFactory(private val catsRepository: CatsRepository) :
     ViewModelProvider.NewInstanceFactory() {
-    override fun <T : ViewModel?> create(modelClass: Class<T>): T =
-        CatsViewModel(catsRepository) as T
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        return CatsViewModel(catsRepository) as T
+    }
 }

flowcats/src/main/java/otus/homework/flowcats/MainActivity.kt

@@ -3,6 +3,11 @@ package otus.homework.flowcats
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import androidx.activity.viewModels
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
+import kotlinx.coroutines.launch
+import kotlin.math.log
 
 class MainActivity : AppCompatActivity() {
 
@@ -14,8 +19,16 @@ class MainActivity : AppCompatActivity() {
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
 
-        catsViewModel.catsLiveData.observe(this){
-            view.populate(it)
+//        catsViewModel.catsLiveData.observe(this){
+//            view.populate(it)
+//        }
+
+        lifecycleScope.launch {
+            repeatOnLifecycle(Lifecycle.State.STARTED) {
+               catsViewModel.catsStateFlow.collect {
+                   it.data?.let { fact -> view.populate(fact) }
+               }
+            }
         }
     }
 }

flowcats/src/main/java/otus/homework/flowcats/Result.kt

@@ -0,0 +1,7 @@
+package otus.homework.flowcats
+
+
+sealed class Result<T>(val data:T? = null) {
+    class Success<T>(data: T?): Result<T>(data)
+    class Error<T>(data: T?): Result<T>(data)
+}

operators/src/androidTest/java/otus/homework/flow/ExampleInstrumentedTest.kt

@@ -1,24 +1,24 @@
 package otus.homework.flow
 
-import androidx.test.platform.app.InstrumentationRegistry
-import androidx.test.ext.junit.runners.AndroidJUnit4
-
-import org.junit.Test
-import org.junit.runner.RunWith
-
-import org.junit.Assert.*
-
-/**
- * Instrumented test, which will execute on an Android device.
- *
- * See [testing documentation](http://d.android.com/tools/testing).
- */
-@RunWith(AndroidJUnit4::class)
-class ExampleInstrumentedTest {
-    @Test
-    fun useAppContext() {
-        // Context of the app under test.
-        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
-        assertEquals("otus.homework.flow", appContext.packageName)
-    }
-}
+//import androidx.test.platform.app.InstrumentationRegistry
+//import androidx.test.ext.junit.runners.AndroidJUnit4
+//
+//import org.junit.Test
+//import org.junit.runner.RunWith
+//
+//import org.junit.Assert.*
+//
+///**
+// * Instrumented test, which will execute on an Android device.
+// *
+// * See [testing documentation](http://d.android.com/tools/testing).
+// */
+//@RunWith(AndroidJUnit4::class)
+//class ExampleInstrumentedTest {
+//    @Test
+//    fun useAppContext() {
+//        // Context of the app under test.
+//        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+//        assertEquals("otus.homework.flow", appContext.packageName)
+//    }
+//}

operators/src/main/java/otus/homework/flow/SampleInteractor.kt

@@ -18,7 +18,18 @@ class SampleInteractor(
      * 6) возвращает результат
      */
     fun task1(): Flow<String> {
-        return flowOf()
+       return sampleRepository.produceNumbers()
+            .map { element ->
+                element * 5
+            }
+            .filter { element ->
+                element > 20
+                element % 2 != 0
+            }
+            .map { element ->
+                "$element won"
+            }
+            .take(3)
     }
 
     /**
@@ -29,7 +40,18 @@ class SampleInteractor(
      * Если число не делится на 3,5,15 - эмитим само число
      */
     fun task2(): Flow<String> {
-        return flowOf()
+       return sampleRepository.produceNumbers()
+            .map { element ->
+                if (element % 15 == 0) {
+                    "$element, FizzBuzz"
+                } else if(element % 3 == 0) {
+                    "$element, Fizz"
+                } else if (element % 5 == 0) {
+                    "$element, Buzz"
+                } else {
+                    element.toString()
+                }
+            }
     }
 
     /**
@@ -38,7 +60,9 @@ class SampleInteractor(
      * Если айтемы в одно из флоу кончились то результирующий флоу также должен закончится
      */
     fun task3(): Flow<Pair<String, String>> {
-        return flowOf()
+        return sampleRepository.produceColors().zip(sampleRepository.produceForms()) { firstFlow, secondFlow ->
+            Pair(firstFlow, secondFlow)
+        }
     }
 
     /**
@@ -48,6 +72,15 @@ class SampleInteractor(
      * При любом исходе, будь то выброс исключения или успешная отработка функции вызовите метод dotsRepository.completed()
      */
     fun task4(): Flow<Int> {
-        return flowOf()
+        return flow {
+            sampleRepository.produceNumbers().catch {
+                if (it is IllegalArgumentException) emit(-1)
+                else throw it
+            }.onCompletion {
+                sampleRepository.completed()
+            }.collect {
+                emit(it)
+            }
+        }
     }
 }

operators/src/test/java/otus/homework/flow/SampleInteractorTest.kt

@@ -1,17 +1,16 @@
 package otus.homework.flow
 
+import io.mockk.InternalPlatformDsl.toArray
 import io.mockk.every
 import io.mockk.mockk
 import io.mockk.verify
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.flow.asFlow
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.flowOf
-import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.test.runBlockingTest
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertThrows
 import org.junit.Test
+import java.util.*
 
 
 @ExperimentalCoroutinesApi
@@ -65,8 +64,7 @@ class SampleInteractorTest {
             "20",
             "Buzz",
             "21",
-            "Fizz"
-        )
+            "Fizz")
         val actual = dotsInteractor.task2().toList()
 
         assertEquals(expected, actual)
@@ -84,6 +82,7 @@ class SampleInteractorTest {
         every { dotsRepository.produceForms() } returns flowOf("Circle", "Square", "Triangle")
 
         val expected = listOf("Red" to "Circle", "Green" to "Square", "Blue" to "Triangle")
+
         val actual = dotsInteractor.task3().toList()
 
         assertEquals(expected, actual)