How can i save shared prefrence in list? - flutter

Question

i have two class , in first class set sharedPrefrence like this :
[{"name":"alex","code":"12345"}]
my shared prefrence set method :
Future _shared() async {
final _customer = {
"name": _controller1.text,
"code": _controller2.text,
};
List<Map<String, dynamic>> customers = [];
customers.add(_customer);
final customerEncode = jsonEncode(customers);
SharedPreferences pref = await SharedPreferences.getInstance();
pref.setString("list_customer", customerEncode);
print(customerEncode);
}
and show this list in second class , i want when back to first class and enter name and code , they are add to previous list(keep later data) like this :
[{"name":"alex","code":"12345"},{"name":"john","code":"98765"}]
how can i do this ?

Answer 1

Create Customer Model:
class Customer{
Customer({this.name, this.code});
String name;
String code;
Customer.fromMap(json)
: name = json['name'].toString(),
code= json['code'].toString();
}
Then, create a method which adds into your SharedPreferences list:
addIntoList(Customer obj){
List<Customer> customersList = new List();
SharedPreferences pref = await SharedPreferences.getInstance();
// get list from SharedPreferences
var customers = pref.getString("list_customer");
var customersDecode = jsonDecode(customers);
// loop through your saved array and get them into customersList
customerDecode.forEach((val) {
customersList.add(Customer.fromMap(val));
});
// at last, add your parameter object
customersList.add(obj);
// save list to SharedPreferences
pref.setString("list_customer", jsonEncode(customersList));
}