Vivek yadav

plugins in flutter

How to build best plugins in Flutter

Agenda

What is Flutter?

What is a Flutter Plugin?

Learn and Build Flutter Plugin

Q & A

Vivek yadav

Lead Mobile Developer @ ZestMoney

Google Developer Expert for Flutter and Dart

Community leader @FlutterMumbai, @IndiaFlutter

Teacher, Mentor, Trainer, and Contributor for Flutter in every possible way

@viveky259259

“Flutter is the best platform to build apps for iPhones and Android phones.”

Vivek Yadav

Google Developer Expert for Flutter & Dart

@viveky259259

Designed for the Future

Let's begin

What is flutter?

Toolkit to build beautiful UIs
Framework to build faster apps
Framework to build for multiple platforms
Single codebase, code once

What is a Flutter Plugin

A specialized Dart package that contains an API written in Dart code combined with one or more platform-specific implementations.

What is a Flutter Package

Packages enable the creation of modular code that can be shared easily.

Understand Flutter Package

Understand Flutter Plugin

Developing packages

All Dart code
Classes, widgets, and functions

Developing Plugin

Flutter Side

All Dart codes
Classes, widgets, and functions
Communication

Platform Side

All Platform codes (Kotlin, swift etc)
Classes, UI elements, and functions
Communication

Implementation

Plugin implementation

flutter create --template=plugin --platforms=android,ios,macos,web,windows,linux flutter_security

1. Create plugin

Plugin implementation

// Kotlin: FlutterSecurityPlugin.kt

override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
    when (call.method){
      "encrypt" -> print("do encryption")
      "decrypt" -> print("do decryption")
       else -> {
          print("Not implemented")
      }
    }
  }

2. Setup Communication

Plugin implementation

// Flutter: flutter_security_platform_interface

 Future<String> encrypt() async {
    throw UnimplementedError('encrypt() has not been implemented.');
  }

  Future<String> decrypt() async {
    throw UnimplementedError('decrypt() has not been implemented.');
  }

2. Setup Communication

Plugin implementation

//flutter_security_method_channel.dart

 @override
  Future<String> decrypt() async {
    final String? decryptedString =
        await methodChannel.invokeMethod<String>('decrypt');
    if (decryptedString != null) {
      return decryptedString;
    } else {
      throw Exception();
    }
  }

2. Setup Communication

//flutter_security_method_channel.dart

  @override
  Future<String> encrypt() async {
    final String? encryptedString =
        await methodChannel.invokeMethod<String>('encrypt');
    if (encryptedString != null) {
      return encryptedString;
    } else {
      throw Exception();
    }
  }

Plugin implementation

// flutter_securiy.dart

class FlutterSecurity {
  Future<String> encrypt() async {
    return FlutterSecurityPlatform.instance.encrypt();
  }

  Future<String> decrypt() async {
    return FlutterSecurityPlatform.instance.decrypt();
  }
}

2. Setup Communication

Plugin implementation

// main.dart

class ExampleApp{

 final String _flutterSecurityPlugin = FlutterSecurity();
 
 _flutterSecurityPlugin.encrypt(plainText);
 
 _flutterSecurityPlugin.decrypt(cipherText);
 
}

3. Use in Flutter App

Plugin implementation

// Encryption.kt

package com.example.flutter_security

class Encryption {

    fun encrypt(plainText: String): String {
      
        return Base64.getEncoder().encodeToString(cipherText)
    }
    
    fun decrypt(cipherText:String):String{

        return cipher.doFinal(Base64.getDecoder().decode(cipherText))
    }
}

4. Add platform implementation