CognitoSecureStorage for Amazon Cognito Identity Dart ( https://pub.dartlang.org/packages/amazon_cognito_identity_dart )

cognito_secure_storage.dart

import 'package:amazon_cognito_identity_dart/cognito.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'dart:convert';

class CognitoSecureStorage extends CognitoStorage {
  FlutterSecureStorage _securePrefs = new FlutterSecureStorage();
  CognitoSecureStorage();

  @override
  Future getItem(String key) async {
    String item;
    try {
      item = json.decode(await _securePrefs.read(key: key));
    } catch (e) {
      return null;
    }
    return item;
  }

  @override
  Future setItem(String key, value) async {
    _securePrefs.write(key: key, value: json.encode(value));
    return getItem(key);
  }

  @override
  Future removeItem(String key) async {
    final item = getItem(key);
    if (item != null) {
      _securePrefs.delete(key: key);
      return item;
    }
    return null;
  }

  @override
  Future<void> clear() async {
    _securePrefs.deleteAll();
  }
}