NavGraphViewModelLazy.kt
/*
* Copyright 2019 The Android Open Source Project
*
* 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.
*/
package androidx.navigation
import androidx.annotation.IdRes
import androidx.annotation.MainThread
import androidx.fragment.app.Fragment
import androidx.fragment.app.createViewModelLazy
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import androidx.lifecycle.ViewModelStore
import androidx.lifecycle.viewmodel.CreationExtras
import androidx.navigation.fragment.findNavController
/**
* Returns a property delegate to access a [ViewModel] scoped to a navigation graph present on the
* [NavController] back stack:
* ```
* class MyFragment : Fragment() {
* val viewmodel: MainViewModel by navGraphViewModels(R.id.main)
* }
* ```
*
* Custom [ViewModelProvider.Factory] can be defined via [factoryProducer] parameter,
* factory returned by it will be used to create [ViewModel]:
* ```
* class MyFragment : Fragment() {
* val viewmodel: MainViewModel by navGraphViewModels(R.id.main) { myFactory }
* }
* ```
*
* This property can be accessed only after this NavGraph is on the NavController back stack,
* and an attempt access prior to that will result in an IllegalArgumentException.
*
* @param navGraphId ID of a NavGraph that exists on the [NavController] back stack
* @param factoryProducer lambda that will be called during initialization to return
* [ViewModelProvider.Factory]. If none is provided, this will use the factory from the
* [NavBackStackEntry] referenced by the [navGraphId].
*/
@Deprecated(
"Superseded by navGraphViewModels that takes a CreationExtras producer",
level = DeprecationLevel.HIDDEN
)
@MainThread
public inline fun <reified VM : ViewModel> Fragment.navGraphViewModels(
@IdRes navGraphId: Int,
noinline factoryProducer: (() -> ViewModelProvider.Factory)? = null
): Lazy<VM> {
val backStackEntry by lazy {
findNavController().getBackStackEntry(navGraphId)
}
val storeProducer: () -> ViewModelStore = {
backStackEntry.viewModelStore
}
return createViewModelLazy(
VM::class, storeProducer,
{ backStackEntry.defaultViewModelCreationExtras },
factoryProducer ?: { backStackEntry.defaultViewModelProviderFactory }
)
}
/**
* Returns a property delegate to access a [ViewModel] scoped to a navigation graph present on the
* [NavController] back stack:
* ```
* class MyFragment : Fragment() {
* val viewmodel: MainViewModel by navGraphViewModels(R.id.main)
* }
* ```
*
* Custom [ViewModelProvider.Factory] can be defined via [factoryProducer] parameter,
* factory returned by it will be used to create [ViewModel]:
* ```
* class MyFragment : Fragment() {
* val viewmodel: MainViewModel by navGraphViewModels(R.id.main) { myFactory }
* }
* ```
*
* This property can be accessed only after this NavGraph is on the NavController back stack,
* and an attempt access prior to that will result in an IllegalArgumentException.
*
* @param navGraphId ID of a NavGraph that exists on the [NavController] back stack
* @param extrasProducer lambda that will be called during initialization to return
* [CreationExtras]. If none is provided, this will use the extras from the [NavBackStackEntry]
* referenced by the [navGraphId].
* @param factoryProducer lambda that will be called during initialization to return
* [ViewModelProvider.Factory]. If none is provided, this will use the factory from the
* [NavBackStackEntry] referenced by the [navGraphId].
*/
@MainThread
public inline fun <reified VM : ViewModel> Fragment.navGraphViewModels(
@IdRes navGraphId: Int,
noinline extrasProducer: (() -> CreationExtras)? = null,
noinline factoryProducer: (() -> ViewModelProvider.Factory)? = null
): Lazy<VM> {
val backStackEntry by lazy {
findNavController().getBackStackEntry(navGraphId)
}
val storeProducer: () -> ViewModelStore = {
backStackEntry.viewModelStore
}
return createViewModelLazy(
VM::class, storeProducer,
{ extrasProducer?.invoke() ?: backStackEntry.defaultViewModelCreationExtras },
factoryProducer ?: { backStackEntry.defaultViewModelProviderFactory }
)
}
/**
* Returns a property delegate to access a [ViewModel] scoped to a navigation graph present on the
* [NavController] back stack:
* ```
* class MyFragment : Fragment() {
* val viewModel: MainViewModel by navGraphViewModels("main")
* }
* ```
*
* Custom [ViewModelProvider.Factory] can be defined via [factoryProducer] parameter,
* factory returned by it will be used to create [ViewModel]:
* ```
* class MyFragment : Fragment() {
* val viewModel: MainViewModel by navGraphViewModels("main") { myFactory }
* }
* ```
*
* This property can be accessed only after this NavGraph is on the NavController back stack,
* and an attempt access prior to that will result in an IllegalArgumentException.
*
* @param navGraphRoute [NavDestination.route] of a NavGraph that exists on the [NavController]
* back stack. If a [NavDestination] with the given route does not exist on the back stack, an
* [IllegalArgumentException] will be thrown.
* @param factoryProducer lambda that will be called during initialization to return
* [ViewModelProvider.Factory]. If none is provided, this will use the factory from the
* [NavBackStackEntry] referenced by the [navGraphRoute].
*/
@Deprecated(
"Superseded by navGraphViewModels that takes a CreationExtras producer",
level = DeprecationLevel.HIDDEN
)
@MainThread
public inline fun <reified VM : ViewModel> Fragment.navGraphViewModels(
navGraphRoute: String,
noinline factoryProducer: (() -> ViewModelProvider.Factory)? = null
): Lazy<VM> {
val backStackEntry by lazy {
findNavController().getBackStackEntry(navGraphRoute)
}
val storeProducer: () -> ViewModelStore = {
backStackEntry.viewModelStore
}
return createViewModelLazy(
VM::class, storeProducer,
{ backStackEntry.defaultViewModelCreationExtras },
factoryProducer ?: { backStackEntry.defaultViewModelProviderFactory }
)
}
/**
* Returns a property delegate to access a [ViewModel] scoped to a navigation graph present on the
* [NavController] back stack:
* ```
* class MyFragment : Fragment() {
* val viewModel: MainViewModel by navGraphViewModels("main")
* }
* ```
*
* Custom [ViewModelProvider.Factory] can be defined via [factoryProducer] parameter,
* factory returned by it will be used to create [ViewModel]:
* ```
* class MyFragment : Fragment() {
* val viewModel: MainViewModel by navGraphViewModels("main") { myFactory }
* }
* ```
*
* This property can be accessed only after this NavGraph is on the NavController back stack,
* and an attempt access prior to that will result in an IllegalArgumentException.
*
* @param navGraphRoute [NavDestination.route] of a NavGraph that exists on the [NavController]
* back stack. If a [NavDestination] with the given route does not exist on the back stack, an
* [IllegalArgumentException] will be thrown.
* @param extrasProducer lambda that will be called during initialization to return
* [CreationExtras]. If none is provided, this will use the extras from the [NavBackStackEntry]
* referenced by the [navGraphRoute].
* @param factoryProducer lambda that will be called during initialization to return
* [ViewModelProvider.Factory]. If none is provided, this will use the factory from the
* [NavBackStackEntry] referenced by the [navGraphRoute].
*/
@MainThread
public inline fun <reified VM : ViewModel> Fragment.navGraphViewModels(
navGraphRoute: String,
noinline extrasProducer: (() -> CreationExtras)? = null,
noinline factoryProducer: (() -> ViewModelProvider.Factory)? = null
): Lazy<VM> {
val backStackEntry by lazy {
findNavController().getBackStackEntry(navGraphRoute)
}
val storeProducer: () -> ViewModelStore = {
backStackEntry.viewModelStore
}
return createViewModelLazy(
VM::class, storeProducer,
{ extrasProducer?.invoke() ?: backStackEntry.defaultViewModelCreationExtras },
factoryProducer ?: { backStackEntry.defaultViewModelProviderFactory }
)
}