44 lines
1.7 KiB
Dart
44 lines
1.7 KiB
Dart
import 'package:shared_preferences/shared_preferences.dart';
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/// Base class for services that use SharedPreferences singleton pattern.
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///
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/// This class handles the boilerplate for singleton initialization and
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/// SharedPreferences lifecycle management. Subclasses should:
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/// 1. Create a private named constructor (e.g., SettingsService._())
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/// 2. Implement their own getInstance() method that calls BaseSharedPreferencesService.initializeInstance()
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/// 3. Optionally override onInit() for post-initialization setup
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abstract class BaseSharedPreferencesService {
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static final Map<Type, BaseSharedPreferencesService> _instances = {};
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late SharedPreferences _prefs;
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/// Protected constructor for subclasses
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BaseSharedPreferencesService();
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/// Access to SharedPreferences instance
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SharedPreferences get prefs => _prefs;
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/// Initialize the SharedPreferences instance
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///
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/// This method handles:
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/// - Singleton instance management
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/// - SharedPreferences initialization
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/// - Calling onInit() hook for subclass-specific setup
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static Future<T> initializeInstance<T extends BaseSharedPreferencesService>(T Function() constructor) async {
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if (_instances[T] == null) {
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final instance = constructor();
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_instances[T] = instance;
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instance._prefs = await SharedPreferences.getInstance();
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await instance.onInit();
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}
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return _instances[T] as T;
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}
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/// Hook for subclass-specific initialization after SharedPreferences is ready.
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///
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/// Override this method to perform any setup that requires access to
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/// SharedPreferences (e.g., registering values with other services).
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Future<void> onInit() async {
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// Default implementation does nothing
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}
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}
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