flutter-plugins

$2a

Instructions

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Gather Plugin Requirements

STOP AND ASK THE USER:

• What is the plugin name?

• What is the organization name (reverse domain notation, e.g., com.example)?

• Which platforms should be supported (comma-separated: android,ios,web,linux,macos,windows)?

• Do you need an FFI plugin or a standard Method Channel plugin?

• Do you prefer Java or Kotlin for Android? Objective-C or Swift for iOS?

• Should this be a federated plugin?

-

Generate the Plugin Package

Execute the Flutter CLI command based on the user's parameters.

Standard Plugin Example:

flutter create --org com.example --template=plugin --platforms=android,ios,macos -a kotlin -i swift my_plugin

FFI Plugin Example:

flutter create --template=plugin_ffi my_ffi_plugin

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Configure Federated Plugin Architecture (If Applicable)

If the user requested a federated plugin, configure the pubspec.yaml of the app-facing package to endorse the platform implementations.

# App-facing pubspec.yaml

flutter:

  plugin:

    platforms:

      android:

        default_package: my_plugin_android

      windows:

        default_package: my_plugin_windows

dependencies:

  my_plugin_android: ^1.0.0

  my_plugin_windows: ^1.0.0

For the platform implementation packages, define the implements key:

# Platform implementation pubspec.yaml (e.g., my_plugin_windows)

flutter:

  plugin:

    implements: my_plugin

    platforms:

      windows:

        pluginClass: MyPlugin

-

Prepare Native Environments for Editing

Before modifying native code, you MUST build the example app to resolve dependencies and generate necessary files.

cd my_plugin/example

flutter build apk --config-only # For Android

flutter build ios --no-codesign --config-only # For iOS

flutter build windows # For Windows

-

Implement Android v2 Embedding Lifecycle

Modify the Android plugin class (e.g., android/src/main/kotlin/com/example/my_plugin/MyPlugin.kt). Extract logic from registerWith() into a private method shared with onAttachedToEngine(). Implement ActivityAware or ServiceAware if context is needed.

package com.example.my_plugin

import androidx.annotation.NonNull

import io.flutter.embedding.engine.plugins.FlutterPlugin

import io.flutter.embedding.engine.plugins.activity.ActivityAware

import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding

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

class MyPlugin: FlutterPlugin, MethodCallHandler, ActivityAware {

  private lateinit var channel : MethodChannel

  override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {

    setupChannel(flutterPluginBinding.binaryMessenger)

  }

  // Shared private method for v1 and v2 embedding compatibility

  private fun setupChannel(messenger: BinaryMessenger) {

    channel = MethodChannel(messenger, "my_plugin")

    channel.setMethodCallHandler(this)

  }

  override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {

    if (call.method == "getPlatformVersion") {

      result.success("Android ${android.os.Build.VERSION.RELEASE}")

    } else {

      result.notImplemented()

    }

  }

  override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {

    channel.setMethodCallHandler(null)

  }

  override fun onAttachedToActivity(binding: ActivityPluginBinding) {

    // Handle Activity attachment

  }

  override fun onDetachedFromActivityForConfigChanges() {}

  override fun onReattachedToActivityForConfigChanges(binding: ActivityPluginBinding) {}

  override fun onDetachedFromActivity() {}

}

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Validate and Fix

Run the plugin tests and analyzer to ensure the generated code is valid.

cd my_plugin

flutter analyze

flutter test

If the analyzer reports missing dependencies or unresolved native symbols, verify that step 4 (building the example app) was executed successfully. Fix any missing imports in the native code blocks.

Constraints

• Never attempt to use Method Channels inside a package created with --template=plugin_ffi. If both are required, use --template=plugin.

• Always build the example project (flutter build <platform>) at least once before attempting to edit or analyze native Android (build.gradle), iOS (.xcworkspace), or Windows (.sln) files.

• Never leave public members undocumented in the Dart API (lib/<package_name>.dart).

• Always use the v2 Android embedding (FlutterPlugin). Do not rely solely on the deprecated PluginRegistry.Registrar.

• Never edit the .android or .ios directories inside a Flutter module; only edit the native code inside the plugin's android/ or ios/ directories.