updating SQLite by firestore listener

Author: konstantinPopovskikh

lib/backend/backend.dart

@@ -39,6 +39,16 @@ Future insertSQLite({required Map<String, dynamic> item}) async {
   // await batch.commit(noResult: true);
 }
 
+Future insertBatchSQLite({required List<Map<String, dynamic>> list}) async {
+  final db = await cacheDatabase();
+  // db.insert('cache', item);
+  final batch = db.batch();
+  for (var item in list) {
+    batch.insert('cache', item, conflictAlgorithm: ConflictAlgorithm.replace);
+  }
+  await batch.commit(noResult: true);
+}
+
 Future updateSQLite({required Map<String, dynamic> item}) async {
   final db = await cacheDatabase();
   db.update('cache', item, where: 'doc_id = ?', whereArgs: [item['doc_id']]);
@@ -49,6 +59,11 @@ Future updateSQLite({required Map<String, dynamic> item}) async {
   // await batch.commit(noResult: true);
 }
 
+Future deleteSQLite({required Map<String, dynamic> item}) async {
+  final db = await cacheDatabase();
+  db.delete('cache', where: 'doc_id = ?', whereArgs: [item['doc_id']]);
+}
+
 // add entry
 Future addBatchOfEntries({required List<dynamic> entries}) async {
   final db = await cacheDatabase();

lib/backend/database.dart

@@ -0,0 +1,45 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:fetchingapp/backend/database.dart';
+import 'package:flutter/foundation.dart';
+
+class FirestoreChanges extends ChangeNotifier {
+  List<Map<String, dynamic>> list = [];
+  Map<String, dynamic> map = {};
+  bool isFirstBoot = true;
+
+  void listenOnFirestoreChanges() {
+    FirebaseFirestore.instance
+        .collection('flutter-caching')
+        .snapshots()
+        .listen((event) {
+      if (isFirstBoot) {
+        cleanDB();
+        for (var change in event.docChanges) {
+          map = {'name': change.doc.data()!['name'], 'doc_id': change.doc.id};
+          list.add(map);
+        }
+        print('first boot');
+        print(list);
+        insertBatchSQLite(list: list);
+        isFirstBoot = false;
+      } else {
+        for (var change in event.docChanges) {
+          map = {'name': change.doc.data()!['name'], 'doc_id': change.doc.id};
+          if (change.type == DocumentChangeType.added) {
+            insertSQLite(item: map);
+          } else if (change.type == DocumentChangeType.modified) {
+            updateSQLite(item: map);
+          } else if (change.type == DocumentChangeType.removed) {
+            deleteSQLite(item: map);
+          }
+          print('Change type: ${change.type};\n'
+              'Doc ID: ${change.doc.id}\n'
+              'Data: ${change.doc.data()}\n\n');
+        }
+      }
+      // notifyListeners();
+    });
+  }
+}
+
+

lib/backend/firestore_changes.dart

@@ -1,4 +1,4 @@
-import 'package:fetchingapp/backend/firestore_changes.dart';
+import 'package:fetchingapp/backend/firestore_listener.dart';
 import 'package:fetchingapp/backend/notifications.dart';
 import 'package:fetchingapp/screens/home.dart';
 import 'package:fetchingapp/screens/login.dart';

lib/backend/firestore_listener.dart

@@ -1,5 +1,4 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
-import 'package:fetchingapp/backend/database.dart';
 import 'package:flutter/material.dart';
 
 class FirestoreCollectionCaching extends StatefulWidget {
@@ -14,17 +13,14 @@ class _FirestoreCollectionCachingState
     extends State<FirestoreCollectionCaching> {
   @override
   Widget build(BuildContext context) {
-    readCache();
-    cleanDB();
-
     return Scaffold(
       appBar: AppBar(
         title: const Text('Firestore Collection'),
       ),
       body: Column(
         children: [
           Expanded(
-            child: Text('List'),
+            child: list(),
           ),
           inputfield(),
         ],
@@ -33,10 +29,14 @@ class _FirestoreCollectionCachingState
   }
 }
 
+Widget list() {
+  return Text('list');
+}
+
 Widget inputfield() {
   final textController = TextEditingController();
 
-  void addEntry() {
+  void addDocToFirebase() {
     if (textController.text == '') {
       return;
     }
@@ -50,7 +50,7 @@ Widget inputfield() {
   return TextField(
       controller: textController,
       onEditingComplete: () {
-        addEntry();
+        addDocToFirebase();
       },
       decoration: InputDecoration(
           prefixIcon: const Icon(Icons.add_circle),
@@ -60,7 +60,7 @@ Widget inputfield() {
             splashColor: Colors.blue,
             tooltip: "Post message",
             onPressed: () {
-              addEntry();
+              addDocToFirebase();
             },
           )));
 }

lib/main.dart

@@ -34,11 +34,6 @@ class HomePage extends StatelessWidget {
                 'Firestore Collection',
                 style: TextStyle(fontSize: 25),
               )),
-          ElevatedButton(
-              onPressed: () {
-                cleanDB();
-              },
-              child: const Text('Clean DB')),
           ElevatedButton(
               onPressed: () {
                 readCache();

lib/screens/firestore_collection.dart

@@ -1,4 +1,4 @@
-import 'package:fetchingapp/backend/firestore_changes.dart';
+import 'package:fetchingapp/backend/firestore_listener.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
@@ -33,7 +33,9 @@ class _ProviderTestPageState extends State<ProviderTestPage> {
               style: TextStyle(fontSize: 25),
             ),
             Text(
-              '\n' + Provider.of<FirestoreChanges>(context).changeStr,
+              '\n'
+              // + Provider.of<FirestoreChanges>(context).changeStr,
+              ,
               style: const TextStyle(fontSize: 15),
             )
           ],