build model class to map to/from firestore - flutter

Question

I'm trying to create classes to match my firestore schema. My schema in firestore is
docID
------------>↓location //Map
↓country //Map
name: "Ireland"
code: "IRE"
↓suburb //Map
name: "Cork"
code: "crk"
↓postcode //Map
name: "4"
code: "4"
I'm a little confused how to model the above. This is what I've done so far..
class VoterData {
VoterData({this.location});
final Location location;
Map<String, dynamic> toMap() {
return {
'location': location,
};
}
factory VoterData.fromMap(Map<String, dynamic> map) {
return VoterData(location: map['location']);
}
}
class Location {
final Suburb suburb;
final Postcode postcode;
final Country country;
Location({this.suburb, this.country, this.postcode});
factory Location.fromJson(Map<String, dynamic> json) => Location(
suburb: json['suburb'],
postcode: json['postcode'],
country: json['country'],
);
Map<String, dynamic> toJson() => {
"suburb": suburb,
"postcode": postcode,
"country": country,
};
}
class Suburb {
String code;
String name;
Suburb({
this.code,
this.name,
});
factory Suburb.fromJson(Map<String, dynamic> json) => Suburb(
code: json["code"],
name: json["name"],
);
Map<String, dynamic> toJson() => {
"code": code,
"name": name,
};
}
class Postcode {
String code;
String name;
Postcode({
this.code,
this.name,
});
factory Postcode.fromJson(Map<String, dynamic> json) => Postcode(
code: json["code"],
name: json["name"],
);
Map<String, dynamic> toJson() => {
"code": code,
"name": name,
};
}
class Country {
String code;
String name;
Country({
this.code,
this.name,
});
factory Country.fromJson(Map<String, dynamic> json) => Country(
code: json["code"],
name: json["name"],
);
Map<String, dynamic> toJson() => {
"code": code,
"name": name,
};
}
I'll looking for my firestore data to be strongly typed to my object model. Suppose I need to write a suburb object to firestore. How would I design my model class ..?

Answer 1

Hi I recommend you use like this class
class DocumentModel {
String collection;
String documentID;
Map<String, dynamic> data;
DataBaseModel(this.collection);
}
class VoterModel extends DocumentModel {
Map<String, dynamic> data = {
'country': { 'name':'', 'code':''},
'suburb': { 'name':'', 'code':'' },
'postcode' : { 'name':'', 'code':'' }
}
VoterModel() : super('<COLLECTION NAME>');
}
so when you get a QuerySnapshot you can parse like this
List<VoterModel> list = querySnapshot.documents.map((DocumentSnapshot docSnapshot) {
VoterModel voter = new VoterModel();
voter.documentID = docSnapshot.documentID;
voter.data = docSnapshot.data;
return voter;
}).toList();
Access to data
list.last.data['country']['name']