get method
get item from cache if its not exists or has expired return null
Implementation
static Future get(String key) async {
MmkvFlutter mmkv = await MmkvFlutter.getInstance();
final value = await mmkv.getString(_getPrefix(key));
if (value == null || value.isEmpty) {
return null;
}
final index = value.indexOf(':');
if (index < 0) {
return null;
}
/// get timespan
final timespan = value.substring(0, index);
final diff =
int.parse(timespan).compareTo(DateTime.now().millisecondsSinceEpoch);
if (diff < 1) {
await mmkv.removeByKey(_getPrefix(key));
return null;
}
/// get user data except `:`
final v = value.substring(index + 1);
return v;
}