Flutter

This is an optional library you can install if you're working with Flutter. It uses an internal queue to make calls fast and non-blocking. It also batches requests and flushes asynchronously, making it perfect to use in any part of your mobile app.

Installation

Warning: This is a community maintained library. It is not officially supported by PostHog.

PostHog is available for install via Pub.

Configuration

Set your PostHog API key and change the automatic event tracking (only for Android and iOS) on if you wish the library to take care of it for you.

Remember that the application lifecycle events won't have any special context set for you by the time it is initialized. If you are using a self-hosted instance of PostHog you will need to have the public hostname or IP for your instance as well.

Android

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.posthog.posthog_flutter_example">
    <application>
        <activity>
            [...]
        </activity>
        <meta-data android:name="com.posthog.posthog.API_KEY" android:value="<ph_project_api_key>" />
        <meta-data android:name="com.posthog.posthog.POSTHOG_HOST" android:value="<ph_instance_address>" />
        <meta-data android:name="com.posthog.posthog.TRACK_APPLICATION_LIFECYCLE_EVENTS" android:value="false" />
        <meta-data android:name="com.posthog.posthog.DEBUG" android:value="false" />
    </application>
</manifest>

iOS

Info.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    [...]
    <key>com.posthog.posthog.API_KEY</key>
    <string><ph_project_api_key></string>
    <key>com.posthog.posthog.POSTHOG_HOST</key>
    <string><ph_instance_address></string>
    <key>com.posthog.posthog.CAPTURE_APPLICATION_LIFECYCLE_EVENTS</key>
    <false/>
    <false/>
    [...]
</dict>
</plist>

Web

HTML

<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8">
  <title>example</title>
</head>

<body>
  <script>
    !function () {
      var analytics = window.analytics = window.analytics || []; if (!analytics.initialize) if (analytics.invoked) window.console && console.error && console.error("PostHog snippet included twice."); else {
        analytics.invoked = !0; analytics.methods = ["captureSubmit", "captureClick", "captureLink", "captureForm", "pageview", "identify", "reset", "group", "capture", "ready", "alias", "debug", "page", "once", "off", "on"]; analytics.factory = function (t) { return function () { var e = Array.prototype.slice.call(arguments); e.unshift(t); analytics.push(e); return analytics } }; for (var t = 0; t < analytics.methods.length; t++) { var e = analytics.methods[t]; analytics[e] = analytics.factory(e) } analytics.load = function (t, e) { var n = document.createElement("script"); n.type = "text/javascript"; n.async = !0; n.src = "https://cdn.posthog.com/analytics.js/v1/" + t + "/analytics.min.js"; var a = document.getElementsByTagName("script")[0]; a.parentNode.insertBefore(n, a); analytics._loadOptions = e }; analytics.SNIPPET_VERSION = "4.1.0";
        analytics.load("YOUR_API_KEY_GOES_HERE");
        analytics.page();
      }
    }();
  </script>
  <script src="main.dart.js" type="application/javascript"></script>
</body>

</html>

For more information please check: https://posthog.com/docs/integrate/client/js

Usage

To use this, add posthog_flutter as a dependency in your pubspec.yaml file.

Supported methods

Method	Android	iOS	Web
`identify`	X	X	X
`capture`	X	X	X
`screen`	X	X	X
`alias`	X	X	X
`getAnonymousId`	X	X	X
`reset`	X	X	X
`disable`	X	X
`enable`	X	X
`debug`	X*	X	X
`setContext`	X	X
`isFeatureEnabled`	X	X	X
`reloadFeatureFlags`	X	X	X
`groups`	X	X	X

Debugging must be set as a configuration parameter in AndroidManifest.xml (see below). The Official PostHog Library does not offer the debug method for Android.

Example

Dart

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Posthog.screen(
      screenName: 'Example Screen',
    );
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('PostHog example app'),
        ),
        body: Center(
          child: FlatButton(
            child: Text('TRACK ACTION WITH POSTHOG'),
            onPressed: () {
              Posthog.capture(
                eventName: 'button_clicked',
                properties: {
                  'foo': 'bar',
                  'number': 1337,
                  'clicked': true,
                  '$set': {
                    'userProp': 'value1',
                    '$groups': {
                      'company': 'twitter',
                    },
                  },
                  '$set_once': {
                    'userProp': 'value2'
                  }
                },
              );
            },
          ),
        ),
      ),
      navigatorObservers: [
        PosthogObserver(),
      ],
    );
  }
}

Capturing events

You can send custom events using capture:

Dart

import 'package:posthog_flutter/posthog_flutter.dart';

Posthog.capture(
  eventName: 'user_signed_up',
);

Tip: We recommend using a '[object][verb]' format for your event names, where '[object]' is the entity that the behavior relates to, and '[verb]' is the behavior itself. For example, project created, user signed up, or invite sent.

Setting event properties

Optionally, you can also include additional information in the event by setting the properties value:

Dart

Posthog.capture(
  eventName: 'user_signed_up',
  properties: {
    'login_type': 'email',
    'is_free_trial': true
  }
);

Feature Flags

PostHog's feature flags enable you to safely deploy and roll back new features.

Boolean feature flags

Dart

Posthog.isFeatureEnabled(
  key: 'flag-key',
);

Multivariate feature flags

Multivariate feature flags are not yet available in our Flutter SDK.

Reloading feature flags

Feature flag values are cached. If something has changed with your user and you'd like to refetch their flag values, call PostHog.reloadFeatureFlags().

Issues

Please file any issues, bugs, or feature requests in our GitHub repository.

Contributing

If you wish to contribute a change to this repo, please send a Pull Request.

Which features are available in this library?

Installation

Configuration

Android

iOS

Web

Usage

Supported methods

Example

Capturing events

Setting event properties

Feature Flags

Boolean feature flags

Multivariate feature flags

Reloading feature flags

Issues

Contributing

Questions?

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