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. In future releases I'm planning to use JSON serializer so it will be much simpler to use. Then pass this class to PreferenceRepository or FuturePreferencesRepository 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 new Person(split[0], int.parse(split[1]));
  }

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

You can also do this using JSON with convert package:

import 'dart:convert';

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

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

}

Then create an instance of either class and pass it to the FuturePreferencesRepository<T>:

var repo = new FuturePreferencesRepository<Person>(new PersonDesSer());
repo.save(new Person("FooBar", 42));
var list = repo.findAll();

Using json_serializable package to generate DesSer

Step 1: import library json_serializable. in pubspec.yaml

dependencies:
  flutter:
    sdk: flutter
  pref_dessert: ^0.4.0+1
  json_serializable: ^3.2.2
  json_annotation: ^3.0.0

dev_dependencies:
  flutter_test:
    sdk: flutter
  build_runner: ^1.0.0

Step 2: Create your class with annotation @JsonSerializable

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

part 'user.g.dart';

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

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

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

  @override
  User fromMap(Map<String, dynamic> map) => _$UserFromJson(map);

  @override
  Map<String, dynamic> toMap(User user) => _$UserToJson(user);
}

Step 3: Run command : flutter pub run build_runner build