Make Json Model for API Call Xml2Json - json

Question

I am calling an Api that returns data in XMl
I then convert it from XML to Json using Xml2Json, to then decode and acheive a JsonMap, which is returning a map well.
When I then go to do locations.fromJson to be able to call data from my model is is returning as null.
I guess converting from XML may complicate but I have tried all possibilities, parsing the entire response, the section I need and modifying the model in all the ways I could.
The data is returning fine as Json, but there is just some disconnect when parsing it with my model, made via quicktype.io
When I call it in any way, be it print or a data retrieval, it returns on null at vehicleActivity
The call
Future<Locations> fetchLiveLocations() async {
var client = http.Client();
var locations;
Xml2Json xml2Json = new Xml2Json();
try{
var response = await client.get(
'https_call');
if (response.statusCode == 200) {
xml2Json.parse(response.body);
var jsonString = xml2Json.toGData();
var jsonMap = json.decode(jsonString);
//jsonMap is returning fine
locations = Locations.fromJson(jsonMap);
//Returning as null
}
} catch(Exception) {
return locations;
}
return locations;
}
Top part of Json Model
import 'dart:convert';
Locations locationsFromJson(String str) => Locations.fromJson(json.decode(str));
String locationsToJson(Locations data) => json.encode(data.toJson());
class Locations {
Locations({
this.vehicleActivity,
});
List<VehicleActivity> vehicleActivity;
factory Locations.fromJson(Map<String, dynamic> json) => Locations(
vehicleActivity: List<VehicleActivity>.from(json["VehicleActivity"].map((x) => VehicleActivity.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"VehicleActivity": List<dynamic>.from(vehicleActivity.map((x) => x.toJson())),
};
}
class VehicleActivity {
VehicleActivity({
this.recordedAtTime,
this.itemIdentifier,
this.validUntilTime,
this.monitoredVehicleJourney,
this.extensions,
});
DateTime recordedAtTime;
String itemIdentifier;
DateTime validUntilTime;
MonitoredVehicleJourney monitoredVehicleJourney;
Extensions extensions;
factory VehicleActivity.fromJson(Map<String, dynamic> json) => VehicleActivity(
recordedAtTime: DateTime.parse(json["RecordedAtTime"]),
itemIdentifier: json["ItemIdentifier"],
validUntilTime: DateTime.parse(json["ValidUntilTime"]),
monitoredVehicleJourney: MonitoredVehicleJourney.fromJson(json["MonitoredVehicleJourney"]),
extensions: Extensions.fromJson(json["Extensions"]),
);
XML File Returned
<Siri xmlns="http://www.siri.org.uk/siri" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.siri.org.uk/siri http://www.siri.org.uk/schema/2.0/xsd/siri.xsd" version="2.0">
<ServiceDelivery>
<ResponseTimestamp>2021-12-03T18:11:05.408806+00:00</ResponseTimestamp>
<ProducerRef>ItoWorld</ProducerRef>
<VehicleMonitoringDelivery>
<ResponseTimestamp>2021-12-03T18:11:05.408806+00:00</ResponseTimestamp>
<RequestMessageRef>5747b24f</RequestMessageRef>
<ValidUntil>2021-12-03T18:16:05.408806+00:00</ValidUntil>
<ShortestPossibleCycle>PT5S</ShortestPossibleCycle>
<VehicleActivity>
<RecordedAtTime>2021-12-03T18:10:01+00:00</RecordedAtTime>
<ItemIdentifier>ad2c7031-ceac-4e7c-bc0c-9e667ad00dfe</ItemIdentifier>
<ValidUntilTime>2021-12-03T18:16:05.408968</ValidUntilTime>
<MonitoredVehicleJourney>
<LineRef>4</LineRef>
<DirectionRef>inbound</DirectionRef>
<FramedVehicleJourneyRef>
<DataFrameRef>2021-12-03</DataFrameRef>
<DatedVehicleJourneyRef>4_20211203_18_04</DatedVehicleJourneyRef>
</FramedVehicleJourneyRef>
<PublishedLineName>4</PublishedLineName>
<OperatorRef>FTVA</OperatorRef>
<DestinationRef>03700324</DestinationRef>
<VehicleLocation>
<Longitude>-0.719601</Longitude>
<Latitude>51.520305</Latitude>
</VehicleLocation>
<Bearing>30.0</Bearing>
<BlockRef>801312</BlockRef>
<VehicleRef>69921</VehicleRef>
</MonitoredVehicleJourney>
<Extensions>
<VehicleJourney>
<Operational>
<TicketMachine>
<TicketMachineServiceCode>B4</TicketMachineServiceCode>
<JourneyCode>1815</JourneyCode>
</TicketMachine>
</Operational>
<VehicleUniqueId>69921</VehicleUniqueId>
<DriverRef>801312</DriverRef>
</VehicleJourney>
</Extensions>
</VehicleActivity>

Answer 1

Here's an example VehicleActivity class - note that it doesn't handle any errors like missing XML tags or unparsable dates, which you should add yourself.
class VehicleActivity {
VehicleActivity({
this.recordedAtTime,
this.itemIdentifier,
this.validUntilTime,
});
DateTime? recordedAtTime;
String? itemIdentifier;
DateTime? validUntilTime;
factory VehicleActivity.fromElement(XmlElement vaElement) => VehicleActivity(
recordedAtTime: DateTime.parse(
vaElement.findElements('RecordedAtTime').first.text,
),
itemIdentifier: vaElement.findElements('ItemIdentifier').first.text,
validUntilTime: DateTime.parse(
vaElement.findElements('ValidUntilTime').first.text,
),
);
}
You would use the factory method from the enclosing tag (similar to how your JSON parsers are written), for each of the vehicle activity tags it finds. (Note that XML can have multiple identically named tags, which is why the code is using first to find the (hopefully) one and only tag. If you want to parse XML correctly you need to deal with this - and note that the trip through JSON could break this - but not with your simple schema.)
Here's a simple example that just finds all the vehicle activity tags:
final doc = XmlDocument.parse(utf8.decode(response.bodyBytes));
final allActivities = doc
.findAllElements('VehicleActivity')
.map((e) => VehicleActivity.fromElement(e))
.toList();
print(allActivities);