How to save list data in SharedPreferences flutter - flutter

Question

I make data connection with database to bring a list of data such as the following code:
var listDATA = [];
Future listDATAs() async {
api = '*************';
var response = await http.post(Uri.parse(api));
var responsebody = jsonDecode(response.body);
if (responsebody.length >0){
for (int i = 0; i < responsebody.length; i++) {
listDATA.add(responsebody[i]['name']+ ':' + responsebody[i]['image'].toString());
}
return responsebody;
}else{
}
}
How can I store listDATA in Shared Preferences I need to save name and image ? Then recall it to display after storage

Answer 1

It's preferred not to store non-primitive data types in SharedPreferences as it supports only primitive data types by default. But still there is a way to do it.
you can store the response body of your API call without decoding JSON to a String value.
// Obtain shared preferences.
final prefs = await SharedPreferences.getInstance();
// Save an String value to 'response' key.
await prefs.setString('response', response.body);
if you have response types of List, you can use setStringList method
await prefs.setStringList('items', <String>['Earth', 'Moon', 'Sun']);

Answer 2

in this way you can store list value in shared preference
static setListValue(String key, List< ProductsModel > value) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
prefs.setString(key, jsonEncode(value.map((e) => e.toJson()).toList()));
}
her I make a standard method to store list values from any class by calling
setListValue('store_list', listData);
after that, you have to make a method for getting this list value
//getListValue
static Future<List<ProductsModel>?> getListValue(String key) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
final dataMap = jsonDecode(prefs.getString(key) ?? '[]') as
List<dynamic>;
return dataMap.map<ProductsModel>((item) {
return ProductsModel.fromJson(item);
}).toList();
}
after that, you can call this method like this
var listValue = await SPUtils.getListValue('store_list');

Answer 3

// for saving the list in shared preferences
final prefs = await SharedPreferences.getInstance();
prefs.setString("list",jsonEncode(listDATA));
// for getting the list from shared preferences
final prefs = await SharedPreferences.getInstance();
List listDATA = jsonDecode(prefs.get("list"));

Answer 4

You can follow those steps.
convert your object to map with toMap() method.
encode your map to string with encode() method.
Save the string to shared preferences.
final SharedPreferences prefs = await SharedPreferences.getInstance();
await prefs.setString('key', encodedData);
// Fetch and decode data
final String musicsString = await prefs.getString('musics_key');
Example :
import 'dart:convert';
void main() async {
final SharedPreferences prefs = await SharedPreferences.getInstance();
final String encodedData = Music.encode([
Music(id: 1, ...),
Music(id: 2, ...),
Music(id: 3, ...),
]);
await prefs.setString('musics_key', encodedData);
// Fetch and decode data final String musicsString = await prefs.getString('musics_key');
final List<Music> musics = Music.decode(musicsString); }
class Music {
final int id;
final String name,
size,
rating,
duration, img; bool favorite;
Music({
this.id,
this.rating,
this.size,
this.duration,
this.name,
this.img,
this.favorite, });
factory Music.fromJson(Map<String, dynamic> jsonData) {
return Music(
id: jsonData['id'],
rating: jsonData['rating'],
size: jsonData['size'],
duration: jsonData['duration'],
name: jsonData['name'],
img: jsonData['img'],
favorite: false,
); }
static Map<String, dynamic> toMap(Music music) => {
'id': music.id,
'rating': music.rating,
'size': music.size,
'duration': music.duration,
'name': music.name,
'img': music.img,
'favorite': music.favorite,
};
static String encode(List<Music> musics) => json.encode(
musics
.map<Map<String, dynamic>>((music) => Music.toMap(music))
.toList(),
);
static List<Music> decode(String musics) =>
(json.decode(musics) as List<dynamic>)
.map<Music>((item) => Music.fromJson(item))
.toList(); }