How to add custom key and value for context?

[cupix-henry-nam]

This package does not provide a way to add custom key and value for context as Kotlin or Swift does?

Another flutter segment package: https://github.com/la-haus/flutter-segment?tab=readme-ov-file#sending-device-tokens-strings-for-push-notifications
swift: https://segment.com/docs/connections/sources/catalog/libraries/mobile/apple/swift-plugin-architecture/
kotlin: https://segment.com/docs/connections/sources/catalog/libraries/mobile/kotlin-android/kotlin-android-plugin-architecture/

[neelkanth-kaushik]

Helo @cupix-henry-nam,

This functionality already exists and can be achieved via a custom plugin. Please refer the Plugin Architecture docs for reference.

A small proof-of-concept is as follows:-

1. Create a Plugin file inside the lib directory (you can create anywhere but change the import path accordingly)

// lib/my_custom_context.dart
import 'package:segment_analytics/analytics.dart';
import 'package:segment_analytics/event.dart';
import 'package:segment_analytics/plugin.dart';

class MyCustomContext extends PlatformPlugin {
  MyCustomContext() : super(PluginType.before);

  final customContext = <String, dynamic>{
    'some_key': 'some custom context value',
  };

  @override
  Future<RawEvent> execute(RawEvent event) async {
    // We need to get the Context in a concurrency safe mode to permit changes to make it in before we retrieve it
    final context = await analytics!.state.context.state;
    context!.custom = customContext;
    context.library = ContextLibrary("analytics-flutter", Analytics.version());
    event.context = context;
    return event;
  }
}

2. Import the plugin in your main.dart file

import 'my_custom_context.dart';

3. Add your plugin in your app

// Initialize the Segment client with your write key
  final analytics = createClient(
    Configuration(
        'WRITE_KEY',
        debug: true, // Enable debug logs
        flushPolicies: [
          CountFlushPolicy(10),
          TimerFlushPolicy(100)
        ],
        collectDeviceId: true
      ),
  );

  analytics.addPlugin(MyCustomContext());  // Add custom context plugin
  runApp(MyApp(analytics: analytics)); // Pass the analytics client here

4. That’s it. Run the App and verify your custom context in the Segment Debugger.

For reference, I am also pasting the entire main.dart file.

import 'package:flutter/material.dart';
import 'package:segment_analytics/analytics.dart';
import 'package:segment_analytics/client.dart';
import 'package:segment_analytics/event.dart';
import 'package:segment_analytics/state.dart';
import 'package:segment_analytics/flush_policies/count_flush_policy.dart';
import 'package:segment_analytics/flush_policies/timer_flush_policy.dart';
import 'my_custom_context.dart';


void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Initialize the Segment client with your write key
  final analytics = createClient(
    Configuration(
        'WRITE_KEY',
        debug: true, // Enable debug logs
        flushPolicies: [
          CountFlushPolicy(10),
          TimerFlushPolicy(100)
        ],
        collectDeviceId: true
      ),
  );

  analytics.addPlugin(MyCustomContext());  // Add custom context plugin
  runApp(MyApp(analytics: analytics)); // Pass the analytics client here
}


class User {
  final String id;
  final String name;
  final String phone;


  User({required this.id, required this.name, required this.phone});
}


class MyApp extends StatelessWidget {
  //const MyApp({super.key});
  final Analytics analytics;

  MyApp({required this.analytics}); // Make sure this constructor is correct

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Segment Trait Reset Demo',
      home: UserSwitcher(
          analytics: analytics), // Pass the analytics client to UserSwitcher
    );
  }
}


class UserSwitcher extends StatefulWidget {
  final Analytics analytics;
  const UserSwitcher({super.key, required this.analytics});
  @override
  _UserSwitcherState createState() => _UserSwitcherState();
}


class _UserSwitcherState extends State<UserSwitcher> {
  User? currentUser;


  final user1 = User(id: '1', name: 'Alice', phone: '111-111');
  final user2 = User(id: '2', name: 'Bob', phone: '222-222');


  void login(User user) async {
    print('Logging in as ${user.name}');
    await widget.analytics.identify(
      userId: user.id,
      userTraits: UserTraits(
        name: user.name,
        phone: user.phone,
      ),
    );
    setState(() {
      currentUser = user;
    });
  }


  void logout() async {
    print('Logging out...');
    await widget.analytics.reset();


    setState(() {
      currentUser = null;
    });
  }


  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Segment Trait Reset Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            if (currentUser == null) ...[
              ElevatedButton(
                onPressed: () => login(user1),
                child: Text('Login as Alice'),
              ),
              ElevatedButton(
                onPressed: () => login(user2),
                child: Text('Login as Bob'),
              ),
            ] else ...[
              Text('Logged in as: ${currentUser!.name}'),
              SizedBox(height: 16),
              ElevatedButton(
                onPressed: logout,
                child: Text('Logout'),
              ),
            ]
          ],
        ),
      ),
    );
  }
}

I hope this resolves your query.