Improve the ViewModel creation approach.

arthur3486 · May 16, 2019 · 1083075 · 1083075
1 parent 332831f
commit 1083075
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Showing 9 changed files with 92 additions and 36 deletions.
diff --git a/app/src/main/java/com/arthurivanets/sample/di/modules/activities/HostModule.kt b/app/src/main/java/com/arthurivanets/sample/di/modules/activities/HostModule.kt
@@ -16,8 +16,7 @@
 
 package com.arthurivanets.sample.di.modules.activities
 
-import androidx.lifecycle.ViewModelProviders
-import com.arthurivanets.mvvm.ViewModelProviderFactory
+import com.arthurivanets.mvvm.util.provideViewModel
 import com.arthurivanets.sample.ui.host.HostActivity
 import com.arthurivanets.sample.ui.host.HostActivityViewModel
 import com.arthurivanets.sample.ui.host.HostActivityViewModelImpl
@@ -30,8 +29,9 @@ class HostModule {
 
     @Provides
     fun provideHostViewModel(activity : HostActivity) : HostActivityViewModel {
-        val viewModelFactory = ViewModelProviderFactory(HostActivityViewModelImpl())
-        return ViewModelProviders.of(activity, viewModelFactory).get(HostActivityViewModelImpl::class.java)
+        return activity.provideViewModel(HostActivityViewModelImpl::class.java) {
+            HostActivityViewModelImpl()
+        }
     }
 
 

diff --git a/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/CharactersModule.kt b/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/CharactersModule.kt
@@ -16,8 +16,7 @@
 
 package com.arthurivanets.sample.di.modules.fragments
 
-import androidx.lifecycle.ViewModelProviders
-import com.arthurivanets.mvvm.ViewModelProviderFactory
+import com.arthurivanets.mvvm.util.provideViewModel
 import com.arthurivanets.sample.domain.repositories.characters.CharactersRepository
 import com.arthurivanets.sample.ui.characters.info.CharacterInfoFragment
 import com.arthurivanets.sample.ui.characters.info.CharacterInfoViewModel
@@ -35,16 +34,18 @@ class CharactersModule {
     @Provides
     fun provideCharactersViewModel(fragment : CharactersFragment,
                                    charactersRepository : CharactersRepository) : CharactersViewModel {
-        val viewModelFactory = ViewModelProviderFactory(CharactersViewModelImpl(charactersRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(CharactersViewModelImpl::class.java)
+        return fragment.provideViewModel(CharactersViewModelImpl::class.java) {
+            CharactersViewModelImpl(charactersRepository)
+        }
     }
 
 
     @Provides
     fun provideCharacterInfoViewModel(fragment : CharacterInfoFragment,
                                       charactersRepository : CharactersRepository) : CharacterInfoViewModel {
-        val viewModelFactory = ViewModelProviderFactory(CharacterInfoViewModelImpl(charactersRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(CharacterInfoViewModelImpl::class.java)
+        return fragment.provideViewModel(CharacterInfoViewModelImpl::class.java) {
+            CharacterInfoViewModelImpl(charactersRepository)
+        }
     }
 
 

diff --git a/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/ComicsModule.kt b/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/ComicsModule.kt
@@ -16,8 +16,7 @@
 
 package com.arthurivanets.sample.di.modules.fragments
 
-import androidx.lifecycle.ViewModelProviders
-import com.arthurivanets.mvvm.ViewModelProviderFactory
+import com.arthurivanets.mvvm.util.provideViewModel
 import com.arthurivanets.sample.domain.repositories.comics.ComicsRepository
 import com.arthurivanets.sample.ui.comics.info.ComicsInfoFragment
 import com.arthurivanets.sample.ui.comics.info.ComicsInfoViewModel
@@ -35,16 +34,18 @@ class ComicsModule {
     @Provides
     fun provideComicsViewModel(fragment : ComicsFragment,
                                comicsRepository : ComicsRepository) : ComicsViewModel {
-        val viewModelFactory = ViewModelProviderFactory(ComicsViewModelImpl(comicsRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(ComicsViewModelImpl::class.java)
+        return fragment.provideViewModel(ComicsViewModelImpl::class.java) {
+            ComicsViewModelImpl(comicsRepository)
+        }
     }
 
 
     @Provides
     fun provideComicsInfoViewModel(fragment : ComicsInfoFragment,
                                    comicsRepository : ComicsRepository) : ComicsInfoViewModel {
-        val viewModelFactory = ViewModelProviderFactory(ComicsInfoViewModelImpl(comicsRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(ComicsInfoViewModelImpl::class.java)
+        return fragment.provideViewModel(ComicsInfoViewModelImpl::class.java) {
+            ComicsInfoViewModelImpl(comicsRepository)
+        }
     }
 
 

diff --git a/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/DashboardModule.kt b/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/DashboardModule.kt
@@ -16,8 +16,7 @@
 
 package com.arthurivanets.sample.di.modules.fragments
 
-import androidx.lifecycle.ViewModelProviders
-import com.arthurivanets.mvvm.ViewModelProviderFactory
+import com.arthurivanets.mvvm.util.provideViewModel
 import com.arthurivanets.sample.ui.dashboard.DashboardFragment
 import com.arthurivanets.sample.ui.dashboard.DashboardViewModel
 import com.arthurivanets.sample.ui.dashboard.DashboardViewModelImpl
@@ -30,8 +29,9 @@ class DashboardModule {
 
     @Provides
     fun provideDashboardViewModel(fragment : DashboardFragment) : DashboardViewModel {
-        val viewModelFactory = ViewModelProviderFactory(DashboardViewModelImpl())
-        return ViewModelProviders.of(fragment, viewModelFactory).get(DashboardViewModelImpl::class.java)
+        return fragment.provideViewModel(DashboardViewModelImpl::class.java) {
+            DashboardViewModelImpl()
+        }
     }
 
 

diff --git a/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/EventsModule.kt b/app/src/main/java/com/arthurivanets/sample/di/modules/fragments/EventsModule.kt
@@ -16,8 +16,7 @@
 
 package com.arthurivanets.sample.di.modules.fragments
 
-import androidx.lifecycle.ViewModelProviders
-import com.arthurivanets.mvvm.ViewModelProviderFactory
+import com.arthurivanets.mvvm.util.provideViewModel
 import com.arthurivanets.sample.domain.repositories.events.EventsRepository
 import com.arthurivanets.sample.ui.events.info.EventInfoFragment
 import com.arthurivanets.sample.ui.events.info.EventInfoViewModel
@@ -35,16 +34,18 @@ class EventsModule {
     @Provides
     fun provideEventsViewModel(fragment : EventsFragment,
                                eventsRepository : EventsRepository) : EventsViewModel {
-        val viewModelFactory = ViewModelProviderFactory(EventsViewModelImpl(eventsRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(EventsViewModelImpl::class.java)
+        return fragment.provideViewModel(EventsViewModelImpl::class.java) {
+            EventsViewModelImpl(eventsRepository)
+        }
     }
 
 
     @Provides
     fun provideEventInfoViewModel(fragment : EventInfoFragment,
                                   eventsRepository : EventsRepository) : EventInfoViewModel {
-        val viewModelFactory = ViewModelProviderFactory(EventInfoViewModelImpl(eventsRepository))
-        return ViewModelProviders.of(fragment, viewModelFactory).get(EventInfoViewModelImpl::class.java)
+        return fragment.provideViewModel(EventInfoViewModelImpl::class.java) {
+            EventInfoViewModelImpl(eventsRepository)
+        }
     }
 
 

diff --git a/common/constants.gradle b/common/constants.gradle
@@ -52,8 +52,8 @@ project.ext {
     releaseRepoName = "maven"
     releaseUserOrg = "arthurlabs"
     releaseGroupId = "com.arthurivanets.mvvm"
-    releaseVersion = "1.0.0"
-    releaseVersionCode = 1
+    releaseVersion = "1.1.0"
+    releaseVersionCode = 2
     releaseWebsite = "https://github.com/arthur3486/android-mvvm"
     releaseLicense = ["Apache-2.0"]
 

diff --git a/mvvm/build.gradle b/mvvm/build.gradle
@@ -56,6 +56,7 @@ dependencies {
 
     implementation kotlinDependencies
     implementation androidCoreDependencies
+    implementation lifecycleDependencies
 
     implementation rxJavaDependencies
     implementation rxBusDependencies

diff --git a/mvvm/src/main/java/com/arthurivanets/mvvm/ViewModelProviderFactory.kt b/mvvm/src/main/java/com/arthurivanets/mvvm/ViewModelProviderFactory.kt
@@ -24,17 +24,20 @@ import androidx.lifecycle.ViewModelProvider
  * <br>
  * Allows you to construct the [ViewModel] that meets your requirements (e.g. perform the dependency injection into your [ViewModel]).
  */
-class ViewModelProviderFactory<V : ViewModel>(private val viewModel : V) : ViewModelProvider.Factory {
-
-
+class ViewModelProviderFactory<V : ViewModel>(
+    private val viewModelClass : Class<V>,
+    private val creator : () -> V
+) : ViewModelProvider.Factory {
+
+
     @SuppressWarnings("unchecked")
     override fun <T : ViewModel?> create(modelClass : Class<T>) : T {
-        if(!modelClass.isAssignableFrom(viewModel::class.java)) {
+        if(!modelClass.isAssignableFrom(viewModelClass)) {
             throw IllegalArgumentException("Unsupported class name.")
         }
-
-        return (viewModel as T)
+        
+        return (creator() as T)
     }
-
-
+    
+    
 }
diff --git a/mvvm/src/main/java/com/arthurivanets/mvvm/util/ViewModelProviderExtensions.kt b/mvvm/src/main/java/com/arthurivanets/mvvm/util/ViewModelProviderExtensions.kt
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2018 Arthur Ivanets, [email protected]
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@file:JvmName("ViewModelProviderUtils")
+
+package com.arthurivanets.mvvm.util
+
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentActivity
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProviders
+import com.arthurivanets.mvvm.ViewModelProviderFactory
+
+
+/**
+ * Provides the [ViewModel] of the specified class using the [ViewModelProviders] and a custom [ViewModelProviderFactory],
+ * thus allowing you to construct a [ViewModel] according to your requirements (e.g. inject the dependencies into it, etc.).
+ * The creation of a new [ViewModel] instance using the [creator] will happen only if the [ViewModelProviders] doesn't have
+ * a retained version of the corresponding [ViewModel] instance, otherwise the existing (retained) [ViewModel] will be reused.
+ */
+fun <T : ViewModel> FragmentActivity.provideViewModel(viewModelClass : Class<T>, creator : () -> T) : T {
+    val viewModelFactory = ViewModelProviderFactory(viewModelClass, creator)
+    return ViewModelProviders.of(this, viewModelFactory).get(viewModelClass)
+}
+
+
+/**
+ * Provides the [ViewModel] of the specified class using the [ViewModelProviders] and a custom [ViewModelProviderFactory],
+ * thus allowing you to construct a [ViewModel] according to your requirements (e.g. inject the dependencies into it, etc.).
+ * The creation of a new [ViewModel] instance using the [creator] will happen only if the [ViewModelProviders] doesn't have
+ * a retained version of the corresponding [ViewModel] instance, otherwise the existing (retained) [ViewModel] will be reused.
+ */
+fun <T : ViewModel> Fragment.provideViewModel(viewModelClass : Class<T>, creator : () -> T) : T {
+    val viewModelFactory = ViewModelProviderFactory(viewModelClass, creator)
+    return ViewModelProviders.of(this, viewModelFactory).get(viewModelClass)
+}