collection_walker

Description:

collection walker

Walk collections in firestore with ease
Features #

Get the size of the collection / query
Get any document by index within a query

Setup #
To use collection walker 2.0.0 and up, you need fire_api_flutter for the database implementation, and the API fire_api for the API. By decoupling from cloud_firestore, this package can technically be used on both flutter apps using firestore & dart servers using firestore through gcp.
Usage #
import 'package:collection_walker/collection_walker.dart';
class SomeScreen extends StatefulWidget {
const SomeScreen({Key? key}) : super(key: key);

@override
State<SomeScreen> createState() => _SomeScreenState();
}

// The state should hold the walker
class _SomeScreenState extends State<SomeScreen> {
late CollectionWalker<SomeData> _walker;

@override
void initState() {
// Create the walker in initState
_walker = CollectionWalker(
chunkSize: 32, // Define a chunk size (usually 1.5x the number of items on screen)
converter: (id, json) => SomeData.fromJson(json)..id = id, // Define a converter (see json_serializable)
query: FirestoreDatabase.instance // Define a query
.collection('some_collection')
.orderBy('some_field'));
// You do not need to dispose the walker as it only contains cached documents, when the state disposes
// The objects cached will be disposed by GC
super.initState();
}

@override
Widget build(BuildContext context) => Scaffold(
// Use a FutureBuilder to get the size of the collection so we can use a listview builder
body: FutureBuilder<int>(
future: _walker.getSize(), // Get the size future of the collection from the walker
builder: (context, snap) => snap.hasData
? ListView.builder( // If we have the size, use a listview builder
itemBuilder: (context, index) => FutureBuilder<SomeData?>(
// Use a future builder to get the data at the index
future: _walker.getAt(index),
// Build it!
builder: (context, snapshot) => snapshot.hasData
? Text(snapshot.data!.name)
: const CircularProgressIndicator(),
),
)
: const Center(child: CircularProgressIndicator()),
),
);
}
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