posthog_dart 0.1.1

Pure-Dart PostHog SDK that works identically on Windows, Linux, Android, iOS, macOS and Web. API-compatible with the official posthog_flutter plugin.

example/lib/main.dart

import 'dart:io' show Platform;

import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';
import 'package:posthog_dart/posthog_dart.dart';

/// Project token. Replace it with a real one, or pass it via `--dart-define`:
///
/// ```
/// flutter run -d windows --dart-define=POSTHOG_KEY=phc_xxx
/// ```
const _projectToken = String.fromEnvironment(
  'POSTHOG_KEY',
  defaultValue: '',
);

const _host = String.fromEnvironment(
  'POSTHOG_HOST',
  defaultValue: 'https://us.i.posthog.com',
);

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  if (_projectToken.isEmpty) {
    debugPrint(
      'POSTHOG_KEY was not provided — the SDK will not start. '
      'Run with: flutter run --dart-define=POSTHOG_KEY=phc_xxx',
    );
  } else {
    final config = PostHogConfig(_projectToken)
      ..host = _host
      ..debug = true
      ..captureApplicationLifecycleEvents = true
      // A small value so events are sent immediately in the example.
      ..flushAt = 1;

    await Posthog().setup(config);
  }

  runApp(const ExampleApp());
}

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

  @override
  Widget build(BuildContext context) {
    // The whole app is wrapped in PostHogWidget for session replay.
    return PostHogWidget(
      child: MaterialApp(
        title: 'PostHog example',
        theme: ThemeData(colorSchemeSeed: Colors.indigo),
        // Collects screen views automatically.
        navigatorObservers: [PosthogObserver()],
        home: const HomePage(),
      ),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  String _status = 'Ready';
  String _distinctId = '';
  String _sessionId = '';

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

  Future<void> _refreshIdentity() async {
    final distinctId = await Posthog().getDistinctId();
    final sessionId = await Posthog().getSessionId();
    if (!mounted) return;
    setState(() {
      _distinctId = distinctId;
      _sessionId = sessionId ?? '(none)';
    });
  }

  Future<void> _run(String label, Future<void> Function() action) async {
    try {
      await action();
      if (!mounted) return;
      setState(() => _status = '$label ✓');
    } catch (e) {
      if (!mounted) return;
      setState(() => _status = '$label ✗ $e');
    }
    await _refreshIdentity();
  }

  String get _platformName {
    if (kIsWeb) return 'Web';
    return Platform.operatingSystem;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('PostHog — $_platformName')),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Status: $_status'),
                  const SizedBox(height: 8),
                  Text('distinct_id: $_distinctId'),
                  Text('session_id: $_sessionId'),
                ],
              ),
            ),
          ),
          const SizedBox(height: 16),
          FilledButton(
            onPressed: () => _run(
              'capture',
              () => Posthog().capture(
                eventName: 'tugma_bosildi',
                properties: {'manba': 'example', 'platforma': _platformName},
              ),
            ),
            child: const Text('Send event'),
          ),
          const SizedBox(height: 8),
          FilledButton.tonal(
            onPressed: () => _run(
              'identify',
              () => Posthog().identify(
                userId: 'example-user',
                userProperties: {'plan': 'pro'},
              ),
            ),
            child: const Text('Identify'),
          ),
          const SizedBox(height: 8),
          FilledButton.tonal(
            onPressed: () => _run(
              'screen',
              () => Posthog().screen(screenName: 'Settings'),
            ),
            child: const Text('Screen event'),
          ),
          const SizedBox(height: 8),
          FilledButton.tonal(
            onPressed: () => _run('exception', () async {
              try {
                throw StateError('Deliberate error for the example');
              } catch (e, s) {
                await Posthog().captureException(error: e, stackTrace: s);
              }
            }),
            child: const Text('Send error'),
          ),
          const SizedBox(height: 8),
          FilledButton.tonal(
            onPressed: () => _run('feature flag', () async {
              final enabled = await Posthog().isFeatureEnabled('example-flag');
              if (!mounted) return;
              setState(() => _status = 'example-flag: $enabled');
            }),
            child: const Text('Check feature flag'),
          ),
          const SizedBox(height: 8),
          OutlinedButton(
            onPressed: () => _run('flush', () => Posthog().flush()),
            child: const Text('Flush (send now)'),
          ),
          const SizedBox(height: 8),
          OutlinedButton(
            onPressed: () => _run('reset', () => Posthog().reset()),
            child: const Text('Reset'),
          ),
          const SizedBox(height: 24),
          const Card(
            child: Padding(
              padding: EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'Masking example',
                    style: TextStyle(fontWeight: FontWeight.bold),
                  ),
                  SizedBox(height: 8),
                  Text('The text below is blacked out in session replay:'),
                  SizedBox(height: 8),
                  PostHogMaskWidget(
                    child: Text('Card number: 4111 1111 1111 1111'),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}