reworked example to include a login + list for better usage of patterns

Author: johsoe

app/build.gradle

@@ -36,7 +36,7 @@ android {
             manifestPlaceholders = [
                     APP_NAME: "MonstarlabDev"
             ]
-            buildConfigField "String", "API_URL", "\"https://jsonplaceholder.typicode.com\""
+            buildConfigField "String", "API_URL", "\"https://reqres.in/api/\""
         }
         staging {
             dimension "default"
@@ -45,15 +45,15 @@ android {
             manifestPlaceholders = [
                     APP_NAME: "MonstarlabStaging"
             ]
-            buildConfigField "String", "API_URL", "\"https://jsonplaceholder.typicode.com\""
+            buildConfigField "String", "API_URL", "\"https://reqres.in/api/\""
         }
         production {
             dimension "default"
             //signingConfig signingConfigs.production
             manifestPlaceholders = [
                     APP_NAME: "Monstarlab",
             ]
-            buildConfigField "String", "API_URL", "\"https://jsonplaceholder.typicode.com\""
+            buildConfigField "String", "API_URL", "\"https://reqres.in/api/\""
         }
     }
 

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.monstarlab">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/com/monstarlab/arch/data/SharedPreferenceDataStore.kt

@@ -1,25 +1,20 @@
 package com.monstarlab.arch.data
 
 import android.content.SharedPreferences
-import kotlinx.serialization.decodeFromString
-import kotlinx.serialization.encodeToString
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.builtins.ListSerializer
 import kotlinx.serialization.json.Json
-import java.lang.Exception
 
 abstract class SharedPreferenceDataStore<T> constructor(
-    private val sharedPreferences: SharedPreferences
+    private val sharedPreferences: SharedPreferences,
+    private val serializer: KSerializer<T>
 ): DataSource<T> {
 
     private val key = this.javaClass.simpleName
 
     override fun getAll(): List<T> {
-        return try {
-            val json = sharedPreferences.getString(key, "") ?: ""
-            val entries = Json.decodeFromString<List<T>>(json)
-            entries
-        } catch (e: Exception) {
-            emptyList()
-        }
+        val json = sharedPreferences.getString(key, "") ?: ""
+        return Json.decodeFromString(ListSerializer(serializer), json)
     }
 
     override fun add(item: T) {
@@ -29,12 +24,8 @@ abstract class SharedPreferenceDataStore<T> constructor(
     }
 
     override fun addAll(items: List<T>) {
-        try {
-            val json = Json.encodeToString(items)
-            sharedPreferences.edit().putString(key, json).apply()
-        } catch (e: Exception) {
-
-        }
+        val json = Json.encodeToString(ListSerializer(serializer), items)
+        sharedPreferences.edit().putString(key, json).apply()
     }
 
     override fun clear() {

app/src/main/java/com/monstarlab/arch/data/SingleDataSource.kt

@@ -0,0 +1,7 @@
+package com.monstarlab.arch.data
+
+interface SingleDataSource<T> {
+    fun get(): T?
+    fun add(item: T)
+    fun clear()
+}

app/src/main/java/com/monstarlab/arch/data/SingleSharedPreferenceDataStore.kt

@@ -0,0 +1,39 @@
+package com.monstarlab.arch.data
+
+import android.content.SharedPreferences
+import kotlinx.serialization.*
+import kotlinx.serialization.json.Json
+import java.lang.Exception
+import kotlin.reflect.KClass
+
+abstract class SingleSharedPreferenceDataStore<T> constructor(
+    private val sharedPreferences: SharedPreferences,
+    private val serializer: KSerializer<T>
+): SingleDataSource<T> {
+
+    private val key = this.javaClass.simpleName
+
+    override fun  get(): T? {
+        return try {
+            val json = sharedPreferences.getString(key, "") ?: ""
+            val entries = Json.decodeFromString(serializer, json)
+            entries
+        } catch (e: Exception) {
+            null
+        }
+    }
+
+
+    override fun add(item: T) {
+        try {
+            val json = Json.encodeToString(serializer, item)
+            sharedPreferences.edit().putString(key, json).apply()
+        } catch (e: Exception) {
+
+        }
+    }
+
+    override fun clear() {
+        sharedPreferences.edit().remove(key).apply()
+    }
+}

app/src/main/java/com/monstarlab/arch/extensions/FlowExtensions.kt

@@ -4,6 +4,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.launch
 
 fun <T1, T2> CoroutineScope.combineFlows(flow1: Flow<T1>, flow2: Flow<T2>, collectBlock: (suspend (T1, T2) -> Unit)) {
@@ -34,4 +35,17 @@ fun <T1, T2, T3, T4> CoroutineScope.combineFlows(flow1: Flow<T1>, flow2: Flow<T2
             // Empty collect block to trigger ^
         }
     }
+}
+
+fun <T> Flow<T>.throttleFirst(windowDuration: Long): Flow<T> = flow {
+    var lastEmissionTime = 0L
+    collect { upstream ->
+        val currentTime = System.currentTimeMillis()
+        val mayEmit = currentTime - lastEmissionTime > windowDuration
+        if (mayEmit)
+        {
+            lastEmissionTime = currentTime
+            emit(upstream)
+        }
+    }
 }

app/src/main/java/com/monstarlab/arch/extensions/RepositoryExtensions.kt

@@ -39,15 +39,15 @@ fun <T, R> Response<out T>.toResultAndMap(transform: (T) -> R): RepositoryResult
 
 sealed class RepositoryResult<out T> {
     data class Success<T>(val value: T): RepositoryResult<T>()
-    data class Error(val error: ErrorModel.Http): RepositoryResult<Nothing>()
+    data class Error(val error: ErrorModel): RepositoryResult<Nothing>()
 }
 
 inline fun <T> RepositoryResult<T>.onSuccess(block: (T) -> Unit): RepositoryResult<T> {
     if(this is RepositoryResult.Success) block.invoke(value)
     return this
 }
 
-inline fun <T> RepositoryResult<T>.onError(block: (ErrorModel.Http) -> Unit): RepositoryResult<T> {
+inline fun <T> RepositoryResult<T>.onError(block: (ErrorModel) -> Unit): RepositoryResult<T> {
     if(this is RepositoryResult.Error) block.invoke(error)
     return this
 }
@@ -56,7 +56,7 @@ fun <T> RepositoryResult<T>.isError(): Boolean {
     return this is RepositoryResult.Error
 }
 
-val <T> RepositoryResult<T>.errorOrNull: ErrorModel.Http?
+val <T> RepositoryResult<T>.errorOrNull: ErrorModel?
     get() {
         return if(this is RepositoryResult.Error) error else null
     }

app/src/main/java/com/monstarlab/arch/extensions/UseCaseExtensions.kt

@@ -27,12 +27,13 @@ inline fun <T> safeFlow(
         crossinline block: suspend () -> RepositoryResult<T>
 ): Flow<UseCaseResult<T>> = flow {
     try {
-        when (val repoResult = block()) {
+        val res = when (val repoResult = block()) {
             is RepositoryResult.Success -> UseCaseResult.Success(repoResult.value)
             is RepositoryResult.Error -> UseCaseResult.Error(repoResult.error)
         }
+        emit(res)
     } catch (e: Exception) {
-        UseCaseResult.Error(e.toError())
+        emit(UseCaseResult.Error(e.toError()))
     }
 }
 

app/src/main/java/com/monstarlab/arch/extensions/ViewExtensions.kt

@@ -1,13 +1,12 @@
 package com.monstarlab.arch.extensions
 
+import android.view.View
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.lifecycleScope
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.collect
-import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.zip
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.*
 
 fun <T> Fragment.collectFlow(targetFlow: Flow<T>, collectBlock: ((T) -> Unit)) {
     safeViewCollect {
@@ -77,4 +76,12 @@ fun <T1, T2> Fragment.zipFlows(flow1: Flow<T1>, flow2: Flow<T2>,  collectBlock:
             }
         }
     }
-}
+}
+
+
+fun View.clicks(throttleTime: Long = 400): Flow<Unit> = callbackFlow {
+    this@clicks.setOnClickListener {
+        offer(Unit)
+    }
+    awaitClose { this@clicks.setOnClickListener(null) }
+}.throttleFirst(throttleTime)

app/src/main/java/com/monstarlab/core/data/network/Api.kt

@@ -1,10 +1,23 @@
 package com.monstarlab.core.data.network
 
 import com.monstarlab.core.data.network.dtos.PostDto
+import com.monstarlab.core.data.network.responses.ResourcesResponse
+import com.monstarlab.core.data.network.responses.TokenResponse
+import com.monstarlab.core.data.network.responses.UserResponse
 import retrofit2.Response
-import retrofit2.http.GET
+import retrofit2.http.*
 
 interface Api {
     @GET("posts")
     suspend fun getPosts(): Response<List<PostDto>>
+
+    @FormUrlEncoded
+    @POST("login")
+    suspend fun postLogin(@Field("email") email: String, @Field("password") password: String): Response<TokenResponse>
+
+    @GET("users/2")
+    suspend fun getUser(): Response<UserResponse>
+
+    @GET("unknown")
+    suspend fun getResources(@Query("page") page: Int = 1): Response<ResourcesResponse>
 }