MutableLiveData

Added in 2.0.0

Kotlin |Java

kotlin.Any
↳	androidx.lifecycle.LiveData
	↳	androidx.lifecycle.MutableLiveData

Known direct subclasses

MediatorLiveData

LiveData subclass which may observe other LiveData objects and react on OnChanged events from them.

LiveData which publicly exposes setValue and postValue method.

Parameters
`<T>`	The type of data hold by this instance

Summary

Public constructors
`MutableLiveData()` Creates a MutableLiveData with no value assigned to it.	android
`MutableLiveData(value: T!)` Creates a MutableLiveData initialized with the given `value`.	android

Public functions
`Unit`	`postValue(value: T!)` Posts a task to a main thread to set the given value.	android
`Unit`	`setValue(value: T!)` Sets the value.	android

`T?`	`getValue()` Returns the current value.	android
`Boolean`	`hasActiveObservers()` Returns true if this LiveData has active observers.	android
`Boolean`	`hasObservers()` Returns true if this LiveData has observers.	android
`Boolean`	`isInitialized()` Returns whether an explicit value has been set on this LiveData.	android
`Unit`	`@MainThread observe(owner: LifecycleOwner, observer: Observer<T!>)` Adds the given observer to the observers list within the lifespan of the given owner.	android
`Unit`	`@MainThread observeForever(observer: Observer<T!>)` Adds the given observer to the observers list.	android
`Unit`	`onActive()` Called when the number of active observers change from 0 to 1.	android
`Unit`	`onInactive()` Called when the number of active observers change from 1 to 0.	android
`Unit`	`@MainThread removeObserver(observer: Observer<T!>)` Removes the given observer from the observers list.	android
`Unit`	`@MainThread removeObservers(owner: LifecycleOwner)` Removes all observers that are tied to the given `LifecycleOwner`.	android

android

Added in 2.0.0

MutableLiveData()

Creates a MutableLiveData with no value assigned to it.

android

Added in 2.1.0

MutableLiveData(value: T!)

Creates a MutableLiveData initialized with the given value.

Parameters
`value: T!`	initial value

android

fun postValue(value: T!): Unit

Posts a task to a main thread to set the given value. So if you have a following code executed in the main thread:

liveData.postValue("a");
liveData.setValue("b");

The value "b" would be set at first and later the main thread would override it with the value "a".

If you called this method multiple times before a main thread executed a posted task, only the last value would be dispatched.

Parameters
`value: T!`	The new value

android

fun setValue(value: T!): Unit

Sets the value. If there are active observers, the value will be dispatched to them.

This method must be called from the main thread. If you need set a value from a background thread, you can use postValue

Parameters
`value: T!`	The new value