firestore_cache 0.2.0

A Flutter plugin for fetching Firestore documents with read from cache first then server.

example/lib/main.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:firestore_cache/firestore_cache.dart';
import 'package:flutter/material.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Firestore Cache Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final _firestore = FirebaseFirestore.instance;
  Future<DocumentSnapshot> _futureDoc;
  Future<QuerySnapshot> _futureSnapshot;

  @override
  void initState() {
    super.initState();
    _futureDoc = _getDoc();
    _futureSnapshot = _getDocs();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Firestore Cache Demo')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            _buildDoc(),
            _buildDocs(),
          ],
        ),
      ),
    );
  }

  Widget _buildDoc() {
    return FutureBuilder<DocumentSnapshot>(
      future: _futureDoc,
      builder: (context, snapshot) {
        if (snapshot.hasError) {
          return Text(snapshot.error);
        } else if (!snapshot.hasData) {
          return CircularProgressIndicator();
        }

        final DocumentSnapshot doc = snapshot.data;

        return Text(
            '${doc.data()['userId']} isFromCache: ${doc.metadata.isFromCache}');
      },
    );
  }

  Widget _buildDocs() {
    return FutureBuilder<QuerySnapshot>(
      future: _futureSnapshot,
      builder: (context, snapshot) {
        if (snapshot.hasError) {
          return Text(snapshot.error);
        } else if (!snapshot.hasData) {
          return CircularProgressIndicator();
        }

        final List<DocumentSnapshot> docs = snapshot.data.docs;

        return Expanded(
          child: ListView(
            children: docs.map((DocumentSnapshot doc) {
              return Text(
                '${doc.data()['postId']} isFromCache: ${doc.metadata.isFromCache}',
                textAlign: TextAlign.center,
              );
            }).toList(),
          ),
        );
      },
    );
  }

  Future<DocumentSnapshot> _getDoc() async {
    final DocumentReference docRef = _firestore.doc('users/user');
    final DocumentSnapshot doc = await FirestoreCache.getDocument(docRef);

    return doc;
  }

  Future<QuerySnapshot> _getDocs() async {
    final DocumentReference cacheDocRef = _firestore.doc('status/status');
    final String cacheField = 'updatedAt';
    final Query query = _firestore.collection('posts');
    final QuerySnapshot snapshot = await FirestoreCache.getDocuments(
      query: query,
      cacheDocRef: cacheDocRef,
      firestoreCacheField: cacheField,
    );

    return snapshot;
  }
}