loon_extension_firestore

Description:

loon extension firestore

Loon Extension Firestore #
The Loon Firestore extension used to easily sync documents fetched remotely from Firestore into the local Loon cache.
Install #
flutter pub add loon_extension_firestore
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Getting started #
Start by enabling the Loon Firestore extension, which will disable the default Firestore cache and enable syncing of Firestore documents to Loon instead.
void main() {
WidgetsFlutterBinding.ensureInitialized();

LoonExtensionFirestore.configure(enabled: true);

return runApp(MyApp());
}
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Data Source #
Next, initialize a data source that defines how to access your data both remotely in Firestore and locally in your Loon cache.
import 'package:loon_extension_firestore/loon_extension_firestore.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

final dataSource = CollectionDataSource(
local: Loon.collection('users'),
remote: FirebaseFirestore.instance.collection('users'),
);
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Any data fetched through the data source will now automatically be written to the cache.
// Fetch the users collection remotely from Firestore
final remoteUsersSnap = await dataSource.remote.get();
// Access the automatically cached users collection in Loon.
final localUsers = dataSource.local.get();
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Typed Data #
If your collection can be parsed into a type-safe data model, then you can specify a serializer on your data source:
class UserModel {
final String id;
final String name;

UserModel({
required this.id,
required this.name,
});

Json toJson() {
return {
"id": id,
"name": name,
}
}
}

final dataSource = CollectionDataSource(
serializer: Serializer(
UserModel.fromJson,
(user) => user.toJson(),
),
local: Loon.collection('users'),
remote: FirebaseFirestore.instance.collection('users'),
);
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This combines the need to specify a converter for the Firestore collection and for the Loon collection reference.
Lifecycle handlers #

onWrite: The onWrite handler can be used to perform a side-effect when a remote Firestore document is written to the local Loon cache.

LoonExtensionFirestore.configure(
enabled: true,
onWrite: (snap) {
print(snap.path); // users__1
},
);

final dataSource = CollectionDataSource(
serializer: Serializer(
UserModel.fromJson,
(user) => user.toJson(),
),
local: Loon.collection('users'),
remote: FirebaseFirestore.instance.collection('users'),
);

final snap = await dataSource.doc('1').remote.get();
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onBeforeWrite: The onBeforeWrite handler fires before a Firestore document is written to the local Loon cache and allows writing of documents to the cache to be canceled if the event returns false.

LoonExtensionFirestore.configure(
enabled: true,
onBeforeWrite: (localDoc, remoteSnap, serializer) {
if (condition) {
return false; // Conditionally do not write to the Loon cache.
}
return true;
}
);
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