Two Object in Firestore Referencing each other - firebase

Question

I have 2 object stored in Firestore Product & Shop
And there maybe a lot of Product and Shop in the future, so I have Shop DocumentReference in Product and vise-versa
Here are how they look like
class Shop extends Equatable {
final String? id;
final String name;
final List<Product?> shopProduct;
final DateTime createDate;
...
static Future<Shop> fromDocument(DocumentSnapshot doc) async {
final data = doc.data() as Map<String, dynamic>;
final shopProductRef = data['shopProduct'];
final List<Product?> shopProductList;
if (shopProductRef.isNotEmpty) {
shopProductList = List.from(shopProductRef.map((ref) async {
Product.fromDocument(await ref!.get());
}));
} else {
shopProductList = [];
}
return Shop(
id: doc.id,
name: data['name'],
shopProduct: shopProductList,
createDate: (data['createDate'] as Timestamp).toDate(),
);
}
And
class Product extends Equatable {
final String? id;
final Shop shop;
final double price;
final String title;
final DateTime date;
...
static Future<Product?> fromDocument(DocumentSnapshot doc) async {
final data = doc.data() as Map<String, dynamic>;
final shopRef = data['shop'] as DocumentReference;
final shopDoc = await shopRef.get();
return Product(
id: doc.id,
shop: await Shop.fromDocument(shopDoc),
price: data['price'],
title: data['title'],
date: (data['date'] as Timestamp).toDate(),
);
}
This is what I think should work in the first place but it brings up a problem that it is causing a loop since both are referencing each other.
I have come up a fix which is creating a second fromDocument method which skip the shopProduct or Shop when I am referencing it.
Is it the only / best way to do it?
Thank you

Answer 1

As I know you have two options
First one is to add a document reference instead of referring to the classes
something like this
class Product extends Equatable {
final String? id;
final DocumentRefrence<Shop> shop;
final double price;
final String title;
final DateTime date;
...
and also do the same for Shop model
class Shop extends Equatable {
final String? id;
final String name;
final List<DocumentReference<Product>?> shopProduct;
final DateTime createDate;
...
Second one is as you mentioned, create a method for Product model and name it for example: Map<String, dynamic> toShopCollection() and use it while setting a shop in firestore and also do the same for Shop model.
cm if you need more details