pref_dessert 1.0.1

Package that allows you persist objects as shared preferences easily. Package name comes from Shared PREFerences DESerializer/SERializer of T (generic) class.

pref_dessert

Package that allows you persist objects as shared preferences easily. Package name comes from: Shared PREFerences DESerializer/SERializer of T (generic) class.

Getting Started

To use this package you just need to extend DesSer<T> class, replace generic T class with the one you want to save in shared preferences. This class requires you to implement two methods to serialize and deserialize objects. Then pass this class along with a SharedPreferences instance to PreferencesRepository and you're good to go!

Example

Person class that you want to serialize:

class Person {
  String name;
  int age;

  Person(this.name, this.age);
}

PersonDesSer which extends DesSer<T> and implements two methods which serialize this objects using CSV format:

class PersonDesSer extends DesSer<Person> {
  @override
  Person deserialize(String s) {
    var split = s.split(",");
    return Person(split[0], int.parse(split[1]));
  }

  @override
  String serialize(Person t) {
    return "${t.name},${t.age}";
  }

  @override
  String get key => "Person";
}

You can also do this using JSON with dart:convert:

import 'dart:convert';

class JsonPersonDesSer extends DesSer<Person> {
  @override
  Person deserialize(String s) {
    var map = json.decode(s);
    return Person(map['name'] as String, map['age'] as int);
  }

  @override
  String serialize(Person t) {
    return json.encode({"name": t.name, "age": t.age});
  }

  @override
  String get key => "Person";
}

Then create a PreferencesRepository<T> with a SharedPreferences instance:

var prefs = await SharedPreferences.getInstance();
var repo = PreferencesRepository<Person>(prefs, PersonDesSer());
repo.save(Person("FooBar", 42));
var list = repo.findAll();

For storing a single element, use SingleElementPreferencesRepository<T>:

var prefs = await SharedPreferences.getInstance();
var repo = SingleElementPreferencesRepository<Person>(prefs, PersonDesSer());
repo.save(Person("FooBar", 42));
var person = repo.find(); // returns Person?

Using json_serializable package to generate DesSer

Step 1: Add json_serializable to your pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  pref_dessert: ^1.0.0
  json_annotation: ^4.11.0

dev_dependencies:
  flutter_test:
    sdk: flutter
  build_runner: ^2.4.0
  json_serializable: ^6.13.0

Step 2: Create your class with @JsonSerializable annotation:

import 'package:json_annotation/json_annotation.dart';
import 'package:pref_dessert/pref_dessert.dart';

part 'user.g.dart';

@JsonSerializable()
class User {
  final String uid;
  final String photoUrl;
  final String displayName;
  final String email;

  User({required this.uid, required this.photoUrl, required this.displayName, required this.email});

  factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json);
  Map<String, dynamic> toJson() => _$UserToJson(this);
}

class UserDesSer extends JsonDesSer<User> {
  @override
  String get key => "PREF_USER";

  @override
  User fromMap(Map<String, dynamic> map) => User.fromJson(map);

  @override
  Map<String, dynamic> toMap(User user) => user.toJson();
}

Step 3: Run code generation: dart run build_runner build