Can i store a Map inside a Shared Preferences in dart?

Question

Is there a way that we could save a map object into shared preferences so that we can fetch the data from shared preferences rather than listening to the database all the ti

Answer 1

If you convert it to a string, you can store it

import 'dart:convert';
...
var s = json.encode(myMap);
// or var s = jsonEncode(myMap);

json.decode(...)/jsonDecode(...) makes a map from a string when you load it.

Answer 2

For those who don't like to convert String to JSON or vice versa, personally recommend localstorage, this is the easiest way I had ever found to store any data<T> in Flutter.

import 'package:localstorage/localstorage.dart';

final LocalStorage store = new LocalStorage('myapp');

...

setLocalStorage() async {
  await store.ready;       // Make sure store is ready
  store.setItem('myMap', myMapData);
}

...

Hope this helps!

Answer 3

Might be easier with this package: https://pub.dartlang.org/packages/pref_dessert

Look at the example:

import 'package:pref_dessert/pref_dessert.dart';

/// 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}";
  }

}

void main() {
  var repo = new FuturePreferencesRepository<Person>(new PersonDesSer());
  repo.save(new Person("Foo", 42));
  repo.save(new Person("Bar", 1));
  var list = repo.findAll();

}

Package is still under development so it might change, but any improvements and ideas are welcomed! :)