Adding collection and subcollection data to model entity from firestore firebase - firebase

Question

I'm recently started using Firebase firestore. I'm stuck at the point were the collection have sub collections and get those items to my model.
Let say I have this collection
meats
\ id : 1
\ name : Chicken
subMeats
\ id : 11
\ name : Country Chicken
\ id : 12
\ name : Broiler Chicken
meats
\ id : 2
\ name : Pork
subMeats
\ id : 21
\ name : White Pork
\ id : 22
\ name : Black Pork
return meatTypeCollection.get().then((value) {
value.docs.forEach((mainDoc) {
// MainMeatEntity.fromSnapshot(mainDoc)
_logger.i(mainDoc.data()['name']);
meatTypeCollection
.doc(mainDoc.id)
.collection('subMeats')
.get()
.then((snapShots) {
snapShots.docs.forEach((doc) {
_logger.i(doc.data()['name']);
MainMeat.fromEntity(MainMeatEntity.fromSnapshot(doc));
});
});
});
//return MeatTypes.fromEntity(MeatTypeEntity.fromJson(value.docs));
}).catchError((error) => _logger.e("Failed to load meat types : $error"));
The above does not capture the collection. I use entity to model.
import 'package:flutter/cupertino.dart';
import 'entities/main_meat_entity.dart';
import 'entities/meat_type_entity.dart';
#immutable
class MainMeat {
final String id;
final String name;
final MeatTypeEntity subMeats;
final String shopId;
const MainMeat({
this.id,
this.name,
this.subMeats,
this.shopId,
});
static MainMeat fromEntity(MainMeatEntity mainMeatEntity) {
return MainMeat(
id: mainMeatEntity.id,
name: mainMeatEntity.name,
subMeats: mainMeatEntity.subMeats,
shopId: mainMeatEntity.shopId,
);
}
MainMeatEntity toEntity() {
return MainMeatEntity(id, name, subMeats, shopId);
}
static const empty = MainMeat(id: '', shopId: "", name: "");
}
-----------------------------****************--------------------
part 'meat_type_entity.g.dart';
#JsonSerializable()
class MeatTypeEntity extends Equatable {
final String id;
final String name;
final String shopId;
const MeatTypeEntity(this.id, this.name, this.shopId);
factory MeatTypeEntity.fromJson(Map<String, dynamic> json) =>
_$MeatTypeEntityFromJson(json);
Map<String, dynamic> toJson() => _$MeatTypeEntityToJson(this);
#override
List<Object> get props => [
id,
name,
shopId,
];
static MeatTypeEntity fromSnapshot(DocumentSnapshot snap) {
return MeatTypeEntity(
snap.id,
snap.data()['name'],
snap.data()["shopId"],
);
}
Map<String, Object> toDocument() {
return {
"id": id,
'mainMeat': name,
"shopId": shopId,
};
}
}
I can list it's collection and sub collections fine. But not sure to load into my model. Any help appreciated thanks.

Answer 1

You can't store subCollection to collection directly, Read FireStore data model section.
So your structure will be look like
Meal(document) -> all meal collection -> Sub Meal (document) -> all sub meals collection.
If you want to read the data like firebase database, you can't read the complete tree/hierarchy at a time.

Answer 2

So assuming this is a Dart question of how to create models, I would create something like this:
class Meat {
final String id;
final String name;
final List<SubMeat> subMeats;
Meat({
#required this.id,
#required this.name,
this.subMeats,
});
}
class SubMeat {
final String id;
final String name;
SubMeat({
#required this.id,
#required this.name,
});
}