Flutter Install Guide

Welcome to the Flutter SDK Installation Guide. This document provides step-by-step instructions for installing and configuring the Ditto SDK, enabling you to sync, query, and insert data seamlessly within your existing Flutter application.

If you’re looking to get started quickly with an existing app we recommend following the Flutter QuickStart.

Prerequisites

Before you begin, ensure you have the following installed:

• Code editor (preferably Visual Studio Code or Android Studio)
• Flutter SDK (version 3.19.0 - 3.24.5)
• An existing Flutter application to integrate Ditto into
• Ditto Portal account with a Ditto App (see Getting SDK Connection Details)

For Android development:

• Android Studio installed on your machine
• A physical Android device or Android emulator
• Upgrade your Kotlin Gradle version to 1.9.20 or later
  1. Navigate to the root folder
  2. Open ./android/settings.gradle
  3. Update the org.jetbrains.kotlin.android plugin to 1.9.20
     plugins {
         // ...
         id "org.jetbrains.kotlin.android" version "1.9.20" apply false
     }
     

For iOS development:

• macOS with the latest version of Xcode installed
• A physical iOS device or an iOS simulator

For Web development:

• Ensure you have Flutter SDK version 3.22.0 - 3.24.5 installed
• Please refer to the Flutter for Web guide for additional information on Ditto’s support for Flutter Web.

Step 1: Add the Ditto Dependency to the Application

1. Run the following command in your terminal from the root of your application:

   flutter pub add ditto_live
   

2. For iOS development, add the following permissions to ios/Runner/Info.plist:

   Info.plist

   <key>NSBluetoothAlwaysUsageDescription</key>
   <string>Uses Bluetooth to connect and sync with nearby devices</string>
   <key>NSBluetoothPeripheralUsageDescription</key>
   <string>Uses Bluetooth to connect and sync with nearby devices</string>
   <key>NSLocalNetworkUsageDescription</key>
   <string>Uses WiFi to connect and sync with nearby devices</string>
   <key>NSBonjourServices</key>
   <array>
     <string>_http-alt._tcp.</string>
   </array>
   

3. For Android development, add the following permissions to android/app/src/main/AndroidManifest.xml.

   <uses-permission android:name="android.permission.BLUETOOTH"
           android:maxSdkVersion="30" />
   <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
           android:maxSdkVersion="30" />
   <uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE"
           tools:targetApi="s" />
   <uses-permission android:name="android.permission.BLUETOOTH_CONNECT"
           tools:targetApi="s" />
   <uses-permission android:name="android.permission.BLUETOOTH_SCAN"
           android:usesPermissionFlags="neverForLocation"
           tools:targetApi="s" />
   <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
           android:maxSdkVersion="32" />
   <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
           android:maxSdkVersion="30" />
   <uses-permission android:name="android.permission.INTERNET" />
   <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
   <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
   <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
   <uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES"
           android:usesPermissionFlags="neverForLocation"
           tools:targetApi="tiramisu" />
   

Step 2: Obtain Ditto AppID and Playground Token

1. Log in to your Ditto Portal account.

2. Navigate to your application and obtain the App ID and Playground Token. (See Getting SDK Connection Details for details)

3. Locate the appID and playground token for your application. These are required to initialize the Ditto SDK.

Step 3: Import and Initialize the Ditto SDK

1. Import the SDK in your Dart file where you plan to use it.

   Dart

   import 'package:ditto_live/ditto_live.dart';
   

2. Import these libraries to request device permissions.

   import 'package:flutter/foundation.dart';
   import 'package:permission_handler/permission_handler.dart';
   

3. Initialize the SDK to obtain an instance of Ditto. This is the main entry point into all Ditto-related functionality.

   Dart

   Future<void> main() async {
     WidgetsFlutterBinding.ensureInitialized();
   
     await Ditto.init();
   
     // Request device permissions on mobile devices
     if (!kIsWeb) {
       await [
         Permission.bluetoothConnect,
         Permission.bluetoothAdvertise,
         Permission.nearbyWifiDevices,
         Permission.bluetoothScan
       ].request();
     }
   
     // Initialize Ditto with your Ditto AppId and Playground Token
     final identity = OnlinePlaygroundIdentity(
       appID: "YOUR_APP_ID", // Replace with your specific id
       token: "YOUR_PLAYGROUND_TOKEN", // Replace with your specific token
     );
     final ditto = await Ditto.open(identity: identity);
   
     // Start Ditto Sync
     ditto.startSync();
   
     runApp(MyApp(ditto: ditto));
   }
   
   class MyApp extends StatelessWidget {
     final Ditto ditto;
   
     const MyApp({super.key, required this.ditto});
   
     @override
     Widget build(BuildContext context) {
       return Placeholder();
     }
   }
   

Step 4: Creating and Observing Data Store Changes

Insert Data into the Ditto Store

To insert data into the Ditto store, use the following example. This demonstrates inserting a document into a collection named items:

Dart

Future<void> insertData() async {
  final item = {'name': 'Sample Item', 'value': 100};
  await ditto.store.execute(
    "INSERT INTO items DOCUMENTS (:item)",
    arguments: {"item": item},
  );
}

Call the insertData function wherever appropriate in your application, such as in a button press handler.

Dart

FloatingActionButton(
  onPressed: insertData,
  child: Icon(Icons.add),
)

Register an Observer to Listen for Data Store Changes

To observe changes in the data store, register an observer. This example sets up an observer to listen for changes in the items collection:

Dart

void observeData() {
  final observer = ditto.store.registerObserver(
    "SELECT * FROM items",
    onChange: (event) {
	    // Handle data changed event
	    print("data changed");
	  },
  );
}

Call the observeData function, typically in the initState method of a stateful widget to start observing when the widget is initialized.

Dart

@override
void initState() {
  super.initState();
  observeData();
}

Remember to cancel your observer in your widget’s dispose() method to prevent resource leaks

Dart

@override
void dispose() {
  _observer.cancel();
  super.dispose();
}

Step 5: Syncing Data

To keep your data in sync across devices and with the Ditto Cloud (Big Peer), you need to register sync subscriptions. Sync subscriptions define the specific data that should be automatically synchronized to the device.

Starting Sync

To start sync on the device you need to call startSync. This enables this device to sync data with other peers including the Ditto Cloud.

Dart

ditto.startSync();

Registering a Subscription

Register a subscription to a collection to keep the data in sync. Below is an example of how to register a subscription to the items collection:

Dart

void syncData() {
  ditto.sync.registerSubscription("SELECT * FROM items");
}

Call the syncData function, typically when initializing your Ditto instance.

Step 6: Syncing Data Offline

Once your application is syncing data using Ditto, you can deploy it to multiple local devices, Android emulators, or iOS simulators. You can then disable the internet to observe the devices syncing offline.

Step 7: Troubleshooting

• Ensure that all dependencies are up-to-date by updating to the latest version.
• Contact the Ditto team through Contact Us