37.3 Saving and Restoring State

An object or value can be saved from within the ViewModel by passing it through to the set() method of the SavedStateHandle instance, providing the key string by which it is to be referenced when performing a retrieval:

private static final String NAME_KEY = "Customer Name";

 

savedStateHandle.set(NAME_KEY, customerName);

When used with LiveData objects, a previously saved value may be restored using the getLiveData() method of the SavedStateHandle instance, once again referencing the corresponding key as follows:

MutableLiveData<String> restoredName = savedStateHandle.getLiveData(NAME_KEY);

To restore a normal (non-LiveData) object, simply use the SavedStateHandle get() method:

String restoredName = savedStateHandle.get(NAME_KEY);

Other useful SavedStateHandle methods include the following:

•contains(String key) - Returns a boolean value indicating whether the saved state contains a value for the...