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Demo

Watch how lifecycle_guard protects your tasks even after app termination:

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The Problem

Ever noticed your background tasks suddenly stop when a user swipes your app away? Modern mobile operating systems (Android 15+ and iOS 13+) are increasingly aggressive at killing processes to save battery.

• User Swipes App: Your Dart Isolate is instantly killed.
• System Pressure: The OS reclaims memory, terminating your "background" thread.
• Battery Optimization: Tasks are deferred or canceled without warning.

If your app is syncing a database, uploading a large file, or processing a payment, you just lost data.

The Solution: lifecycle_guard

lifecycle_guard creates a Native Protection Layer around your critical tasks. By bridging to native Foreground Services (Android) and Background Processing Tasks (iOS), it ensures your logic completes even if the UI process is wiped from memory.

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Key Benefits

• Survival-First: Survives app swipes, low-memory kills, and doze modes.
• Android 15 Ready: Built-in support for foregroundServiceType: dataSync.
• iOS BGTask Integration: Properly utilizes Apple's BGTaskScheduler.
• Zero Config Isolation: Automatically boots a secondary engine for your task.
• Developer Friendly: 100% type-safe API with simple payload support.

When to Use

• Data Syncing: Sending offline records to your server.
• File Processing: Compressing or encrypting local files.
• Media Uploads: Ensuring a user's video actually finishes uploading.
• State Updates: Finalizing critical database transactions.

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Step-by-Step Installation

1. Add to dependencies

Add this to your pubspec.yaml:

dependencies:
  lifecycle_guard: ^1.0.1

2. Platform Setup (REQUIRED)

You must configure the native layer for the guard to hold.

Android Configuration

Open android/app/src/main/AndroidManifest.xml:

1. Add Permissions (outside <application>):

   <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
   <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
   <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
   

2. Declare Service (inside <application>):

   <service
       android:name="com.crealify.lifecycle_guard_android.LifecycleService"
       android:foregroundServiceType="dataSync"
       android:exported="false">
   </service>
   

iOS Configuration

1. Xcode Capabilities: Enable Background Modes and check Background fetch & Background processing.
2. Info.plist: Register the task identifier:

   <key>BGTaskSchedulerPermittedIdentifiers</key>
   <array>
       <string>com.crealify.lifecycle_guard.background_task</string>
   </array>
   

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Full Copy-Paste Example

A complete main.dart showing a button that triggers a protected task.

import 'package:flutter/material.dart';
import 'package:lifecycle_guard/lifecycle_guard.dart';

void main() {
  // 1. Ensure Flutter bindings are ready
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const MaterialApp(home: GuardExample()));
}

class GuardExample extends StatelessWidget {
  const GuardExample({super.key});

  // 2. This function triggers the protection
  Future<void> _triggerSecureTask() async {
    try {
      // The 'Guard' boots here. 
      // After this call, you can swipe the app away and the task will continue.
      await LifecycleGuard.runSecureTask(
        id: "sync_records_001",
        payload: {
          "user_id": "usr_99",
          "action": "sync_offline_db",
          "timestamp": DateTime.now().toIso8601String(),
        },
      );
      
      // The code below continues to run in a protected state
      debugPrint("Guard is active. You can now close the app.");
      
    } catch (e) {
      debugPrint("Failed to start guard: $e");
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('lifecycle_guard Demo')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Icon(Icons.security, size: 80, color: Colors.blue),
            const SizedBox(height: 20),
            const Text(
              'Click the button, then swipe the app away\nfrom the multitasking view!',
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 14, color: Colors.grey),
            ),
            const SizedBox(height: 30),
            ElevatedButton(
              onPressed: _triggerSecureTask,
              style: ElevatedButton.styleFrom(
                padding: const EdgeInsets.symmetric(horizontal: 30, vertical: 15),
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
              ),
              child: const Text('Start Protected Background Task'),
            ),
          ],
        ),
      ),
    );
  }
}

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Platform-Specific Full Examples

If you want to target a specific platform directly, you can use these full-code snippets.

Android Implementation (Full main.dart)

This uses the Android-specific package to trigger a Foreground Service.

import 'package:flutter/material.dart';
import 'package:lifecycle_guard_android/lifecycle_guard_android.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const MaterialApp(home: AndroidGuardExample()));
}

class AndroidGuardExample extends StatelessWidget {
  const AndroidGuardExample({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Android Guard Demo')),
      body: Center(
        child: ElevatedButton(
          onPressed: () async {
            // Triggers Android-specific Foreground Service (dataSync)
            await LifecycleGuardAndroid().runSecureTask(
              id: "android_backup_sync",
              payload: {"priority": "max"},
            );
          },
          child: const Text('Start Android Protected Sync'),
        ),
      ),
    );
  }
}

iOS Implementation (Full main.dart)

This uses the iOS-specific package to schedule a BGTask.

import 'package:flutter/material.dart';
import 'package:lifecycle_guard_ios/lifecycle_guard_ios.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const MaterialApp(home: IosGuardExample()));
}

class IosGuardExample extends StatelessWidget {
  const IosGuardExample({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('iOS Guard Demo')),
      body: Center(
        child: ElevatedButton(
          onPressed: () async {
            // Registers an iOS-specific BGProcessingTask
            await LifecycleGuardIos().runSecureTask(
              id: "ios_background_upload",
              payload: {"retries": 3},
            );
          },
          child: const Text('Schedule iOS BGTask'),
        ),
      ),
    );
  }
}

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License

BSD 3-Clause License — see LICENSE for details.

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