SavedStateHandle

Kotlin |Java

class SavedStateHandle

kotlin.Any
↳	androidx.lifecycle.SavedStateHandle

A handle to saved state passed down to androidx.lifecycle.ViewModel. You should use SavedStateViewModelFactory if you want to receive this object in ViewModel's constructor.

This is a key-value map that will let you write and retrieve objects to and from the saved state. These values will persist after the process is killed by the system and remain available via the same object.

You can read a value from it via get(String) or observe it via androidx.lifecycle.LiveData returned by getLiveData(String).

You can write a value to it via set(String, Object) or setting a value to androidx.lifecycle.MutableLiveData returned by getLiveData(String).

Summary

Public constructors
`<init>(@NonNull initialState: MutableMap<String!, Any!>)` Creates a handle with the given initial arguments.
`<init>()` Creates a handle with the empty state.

Public methods
Unit	`clearSavedStateProvider(@NonNull key: String)` Clear any `SavedStateProvider` that was previously set via `setSavedStateProvider(String, SavedStateProvider)`.
Boolean	`contains(@NonNull key: String)`
T?	`get(@NonNull key: String)` Returns a value associated with the given key.
MutableLiveData<T>	`getLiveData(@NonNull key: String)` Returns a `androidx.lifecycle.LiveData` that access data associated with the given key.
MutableLiveData<T>	`getLiveData(@NonNull key: String, initialValue: T)` Returns a `androidx.lifecycle.LiveData` that access data associated with the given key.
MutableSet<String!>	`keys()` Returns all keys contained in this `SavedStateHandle`
T?	`remove(@NonNull key: String)` Removes a value associated with the given key.
Unit	`set(@NonNull key: String, @Nullable value: T?)` Associate the given value with the key.
Unit	`setSavedStateProvider(@NonNull key: String, @NonNull provider: SavedStateRegistry.SavedStateProvider)` Set a `SavedStateProvider` that will have its state saved into this SavedStateHandle.

Public constructors

<init>

SavedStateHandle(@NonNull initialState: MutableMap<String!, Any!>)

Creates a handle with the given initial arguments.

<init>

SavedStateHandle()

Creates a handle with the empty state.

Public methods

clearSavedStateProvider

@MainThread fun clearSavedStateProvider(@NonNull key: String): Unit

Clear any SavedStateProvider that was previously set via setSavedStateProvider(String, SavedStateProvider). Note: calling this method within SavedStateProvider#saveState() is supported, but will only affect future state saving operations.

Parameters
`key`	String: a key previously used with `setSavedStateProvider`

contains

@MainThread fun contains(@NonNull key: String): Boolean

Return
`Boolean`	true if there is value associated with the given key.

get

@MainThread @Nullable fun <T : Any!> get(@NonNull key: String): T?

Returns a value associated with the given key.

getLiveData

@MainThread @NonNull fun <T : Any!> getLiveData(@NonNull key: String): MutableLiveData<T>

Returns a androidx.lifecycle.LiveData that access data associated with the given key.

See Also

#getLiveData(String, Object)

getLiveData

@MainThread @NonNull fun <T : Any!> getLiveData(
    @NonNull key: String, 
    initialValue: T
): MutableLiveData<T>

Returns a androidx.lifecycle.LiveData that access