shared_preferences_field_delegate

This package allows to work with shared preferences as fields that have value getter, setter and a stream of changes

This package depends on field_delegate. It is an abstract mutable field delegate that can be used as an interface to access different data sources.

Usage

To create a SharedPreferencesField you need to create a SharedPreferencesFieldFactory and call a method with the desired type and pass the key by which the value can be requested from shared preferences. For example SharedPreferencesFieldFactory().int('key')

final fieldFactory = SharedPreferencesFieldFactory(sharedPreferences);
Field<int?> intField = factory.int(intFieldKey);
int value = intField.get();
Future<void> result = intField.set(1);
Stream<int> changes = intField.onChanged;

SharedPreferencesField has generic type and by default it is nullable, but you can add a default value to make the non-nullable Field

Field<int?> intNullableField;
Field<int> notNullableField = Field.notNullable(
  source: nullableFiled,
  defaultValue: 0,
);

You can map value of Field to other type with Field.map function

Field<int> intField;
Field<String> mappedField = Field.map<int, String>(
  source: intField,
  mapToSource: (value) => int.parse(value),
  mapFromSource: (value) => value.toString(),
);

SharedPreferencesFieldFactory has a dispose method to cancel the stream of created fields in this factory

final fieldFactory = SharedPreferencesFieldFactory(sharedPreferences);
Field<int?> intField = factory.int(intFieldKey);
//...
fieldFactory.dispose();