How to add a Flutter Plugin without publishing to Pub (Android)

Feb 13, 2019(6 years ago)-

Fuxing Loh

I was looking for a way to quickly create Flutter Plugin. I can’t seem to find the exact same plugin on https://pub.dev or any solution about embedding the plugin directly into your Flutter App.

The plugin that I want to implement is the Facebook App Events plugin. Since I needed this plugin for the Android platform only. I wasn’t about to publish a half complete Plugin into https://pub.dev.

Step 1: Create the Dart files in /lib

import 'dart:async';
 
import 'package:flutter/services.dart';
import 'package:meta/meta.dart';
 
class FacebookAppEvents {
  factory FacebookAppEvents() => _instance;
 
  FacebookAppEvents.private(MethodChannel platformChannel) : _channel = platformChannel;
 
  final MethodChannel _channel;
 
  static final FacebookAppEvents _instance = FacebookAppEvents.private(const MethodChannel('facebook_app_events'));
 
  Future<void> logEvent({@required String name, Map<String, dynamic> parameters}) async {
    await _channel.invokeMethod('logEvent', <String, dynamic>{
      'name': name,
      'parameters': parameters,
    });
  }
 
  Future<void> setUserId(String id) async {
    await _channel.invokeMethod('setUserId', id);
  }
 
  Future<void> clearUserData() async {
    await _channel.invokeMethod('clearUserData');
  }
}

Step 2: Create the Java Plugin in /android/app/src/

package app.munch.facebookappevents;
 
import android.os.Bundle;
import com.facebook.appevents.AppEventsLogger;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;
import io.flutter.plugin.common.PluginRegistry.Registrar;
 
import java.util.Map;
 
public class FacebookAppEventsPlugin implements MethodCallHandler {
 
    private final AppEventsLogger logger;
 
    public FacebookAppEventsPlugin(Registrar registrar) {
        this.logger = AppEventsLogger.newLogger(registrar.activity());
    }
 
    public static void registerWith(Registrar registrar) {
        final MethodChannel channel = new MethodChannel(registrar.messenger(), "facebook_app_events");
        channel.setMethodCallHandler(new FacebookAppEventsPlugin(registrar));
    }
 
    @Override
    public void onMethodCall(MethodCall call, Result result) {
        switch (call.method) {
            case "logEvent":
                handleLogEvent(call, result);
                break;
            // ...
            default:
                result.notImplemented();
                break;
        }
    }
 
    private void handleLogEvent(MethodCall call, Result result) {
        @SuppressWarnings("unchecked")
        Map<String, Object> arguments = (Map<String, Object>) call.arguments;
        final String eventName = (String) arguments.get("name");
 
        @SuppressWarnings("unchecked") final Bundle parameterBundle =
                createBundleFromMap((Map<String, Object>) arguments.get("parameters"));
        logger.logEvent(eventName, parameterBundle);
        result.success(null);
    }
}

Step 3: Register in MainActivity.java

MainActivity.java

package app.munch.munchapp;
 
import android.os.Bundle;
import app.munch.facebookappevents.FacebookAppEventsPlugin;
import io.flutter.app.FlutterActivity;
import io.flutter.plugins.GeneratedPluginRegistrant;
 
public class MainActivity extends FlutterActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        GeneratedPluginRegistrant.registerWith(this);
        FacebookAppEventsPlugin.registerWith(this.registrarFor("io.flutter.plugins.facebookappevents.FacebookAppEventsPlugin"));
    }
}

Step 4: Run your App

That’s all.

If you’re interested in implementing FacebookAppEvents for Android. Here is the gist: https://gist.github.com/Fuxingloh/4f565b683ba84914c20e090061f2ad80