MutablePreferences

Artifact: androidx.datastore:datastore-preferences-core

Added in 1.0.0

Kotlin |Java

public final class MutablePreferences extends Preferences

java.lang.Object
↳	androidx.datastore.preferences.core.Preferences
	↳	androidx.datastore.preferences.core.MutablePreferences

Mutable version of Preferences. Allows for creating Preferences with different key-value pairs.

Summary

Public methods
`@NonNull Map<@NonNull Preferences.Key<@NonNull ?>, @NonNull Object>`	`asMap()` Retrieve a map of all key preference pairs.
`final void`	`clear()`
`boolean`	`<T extends Object> contains(@NonNull Preferences.Key<@NonNull T> key)` Returns true if this Preferences contains the specified key.
`boolean`	`equals(Object other)`
`T`	`<T extends Object> get(@NonNull Preferences.Key<@NonNull T> key)` Get a preference with a key.
`int`	`hashCode()`
`final void`	`minusAssign(@NonNull Preferences.Key<@NonNull ?> key)` Removes the preference with the given key from this MutablePreferences.
`final void`	`plusAssign(@NonNull Preferences.Pair<@NonNull ?> pair)` Appends or replaces all `pair` to this MutablePreferences.
`final void`	`plusAssign(@NonNull Preferences prefs)` Appends or replaces all pairs from `prefs` to this MutablePreferences.
`final void`	`putAll(@NonNull Preferences.Pair<@NonNull ?>... pairs)` Appends or replaces all `pairs` to this MutablePreferences.
`final @NonNull T`	`<T extends Object> remove(@NonNull Preferences.Key<@NonNull T> key)` Remove a preferences from this MutablePreferences.
`final void`	`<T extends Object> set(@NonNull Preferences.Key<@NonNull T> key, @NonNull T value)` Set a key value pair in MutablePreferences.
`@NonNull String`	`toString()` For better debugging.

Inherited methods

From androidx.datastore.preferences.core.Preferences

`final @NonNull MutablePreferences`	`toMutablePreferences()` Gets a mutable copy of Preferences which contains all the preferences in this Preferences.
`final @NonNull Preferences`	`toPreferences()` Gets a read-only copy of Preferences which contains all the preferences in this Preferences.

Public methods

asMap

public @NonNull Map<@NonNull Preferences.Key<@NonNull ?>, @NonNull Object> asMap()

Retrieve a map of all key preference pairs. The returned map is unmodifiable, and attempts to mutate it will throw runtime exceptions.

Returns
`@NonNull Map<@NonNull Preferences.Key<@NonNull ?>, @NonNull Object>`	a map containing all the preferences in this Preferences

clear

Added in 1.0.0

public final void clear()

contains

public boolean <T extends Object> contains(@NonNull Preferences.Key<@NonNull T> key)

Returns true if this Preferences contains the specified key.

Parameters
`@NonNull Preferences.Key<@NonNull T> key`	the key to check for

equals

public boolean equals(Object other)

get

public T <T extends Object> get(@NonNull Preferences.Key<@NonNull T> key)

Get a preference with a key. If the key is not set, returns null.

If T is Set, this returns an unmodifiable set which will throw a runtime exception when mutated. Do not try to mutate the returned set.

Use MutablePreferences.set to change the value of a preference (inside a DataStore

.edit block).

Parameters
`<T extends Object>`	the type of the preference
`@NonNull Preferences.Key<@NonNull T> key`	the key for the preference

Throws
`kotlin.ClassCastException`	if there is something stored with the same name as `key` but it cannot be cast to T

hashCode

public int hashCode()

minusAssign

Added in 1.0.0

public final void minusAssign(@NonNull Preferences.Key<@NonNull ?> key)

Removes the preference with the given key from this MutablePreferences. If this Preferences does not contain the key, this is a no-op.

Example usage: mutablePrefs -= COUNTER_KEY

Parameters
`@NonNull Preferences.Key<@NonNull ?> key`	the key to remove from this MutablePreferences

plusAssign

Added in 1.0.0

public final void plusAssign(@NonNull Preferences.Pair<@NonNull ?> pair)

Appends or replaces all pair to this MutablePreferences.

Example usage: mutablePrefs += COUNTER_KEY to 100

Parameters
`@NonNull Preferences.Pair<@NonNull ?> pair`	the Preference.Pair to add to this MutablePreferences

plusAssign

Added in 1.0.0

public final void plusAssign(@NonNull Preferences prefs)

Appends or replaces all pairs from prefs to this MutablePreferences. Keys in prefs will overwrite keys in this Preferences.

Example usage: mutablePrefs += preferencesOf(COUNTER_KEY to 100, NAME to "abcdef")

Parameters
`@NonNull Preferences prefs`	Preferences to append to this MutablePreferences

putAll

Added in 1.0.0

public final void putAll(@NonNull Preferences.Pair<@NonNull ?>... pairs)

Appends or replaces all pairs to this MutablePreferences.

Parameters
`@NonNull Preferences.Pair<@NonNull ?>... pairs`	the pairs to append to this MutablePreferences

remove

Added in 1.0.0

public final @NonNull T <T extends Object> remove(@NonNull Preferences.Key<@NonNull T> key)

Remove a preferences from this MutablePreferences.

Parameters
`@NonNull Preferences.Key<@NonNull T> key`	the key to remove this MutablePreferences

Returns
`@NonNull T`	the original value of this preference key.

set

Added in 1.0.0

public final void <T extends Object> set(@NonNull Preferences.Key<@NonNull T> key, @NonNull T value)

Set a key value pair in MutablePreferences.

Example usage: val COUNTER_KEY = intPreferencesKey("counter")

// Once edit completes successfully, preferenceStore will contain the incremented counter. preferenceStore.edit { prefs: MutablePreferences -> prefs\[COUNTER_KEY\] = prefs\[COUNTER_KEY\] :? 0 + 1 }

Parameters
`@NonNull Preferences.Key<@NonNull T> key`	the preference to set
`@NonNull T value`	the value to set the preference to

toString

public @NonNull String toString()

For better debugging.