This was an issue that has plagued me until I figured that I could implement a crude from method to handle the conversion of encoded Json Objects/strings or Dart Maps to the desired class.
Below is a simple example that also handles nulls and accepts JSON (as the string parameter)
import 'dart:convert';
class PaymentDetail
{
String AccountNumber;
double Amount;
int ChargeTypeID;
String CustomerNames;
PaymentDetail({
this.AccountNumber,
this.Amount,
this.ChargeTypeID,
this.CustomerNames
});
PaymentDetail from ({ string : String, object : Map }) {
var map = (object==null) ? (string==null) ? Map() : json.decode(string) : (object==null) ? Map() : object;
return new PaymentDetail(
AccountNumber : map["AccountNumber"] as String,
Amount : map["Amount"] as double,
ChargeTypeID : map["ChargeTypeID"] as int,
CustomerNames : map["CustomerNames"] as String
);
}
}
Below is it's implementation
PaymentDetail payDetail = new PaymentDetail().from(object: new Map());
PaymentDetail otherPayDetail = new PaymentDetail().from(object: {"AccountNumber": "1234", "Amount": 567.2980908});
Once again, this is simplistic and tedious to clone throughout the project but it works for simple cases.