Listing plant varieties - Efficiently managing large Cloud Firestore lists

list_plant_varieties.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter/material.dart';

import 'package:grow_smart/blocs/homestead/bloc.dart';
import 'package:grow_smart/services/service_locator.dart';

class ListPlantVarieties extends StatelessWidget {
  @override
  build(context) {
    final homesteadBloc = BlocProvider.of<HomesteadBloc>(context);
    final stream = locator<Firestore>()
        .collection('indices')
        .where('indexName', isEqualTo: 'plant-varieties')
        .where('parentId', whereIn: ['root', homesteadBloc.state]).snapshots();

    return Scaffold(
      body: StreamBuilder<QuerySnapshot>(
        stream: stream,
        builder: (_, snapshot) {
          if (!snapshot.hasData) {
            return const CircularProgressIndicator();
          }

          return ListView(
              children: snapshot.data.documents.fold(
            [],
            (acc, document) {
              acc.addAll(
                document.data.keys.map((key) => ListTile(title: Text(key))),
              );
              return acc;
            },
          ));
        },
      ),
    );
  }
}