flutter_icp_auth

flutter_icp_auth:

This Flutter package simplifies integrating ICP internet identity authentication flow within your Flutter application.

✨ Features

• LOG IN: Enables users to log in using internet identity.
• AUTO LOGIN: Allows users to log in automatically.
• RELOAD: Automatically logs in users when the app is reloaded or opened, based on session data/delegationObject.
• LOGOUT: Provides functionality for users to log out.

⚠️ Important Info

1. isLocal is used to denote whether you are running your application using mainnet links or locally.

• Change the bool value based on your apps requirement.
• If isLocal is true then replace the values of backendCanisterId and middlePageCanisterId with the locally deployed canister ids.
• If isLocal is false then replace the values of backendCanisterId and middlePageCanisterId with the main-net deployed canister ids.

2. For local or main-net backendCanisterId make sure you have the following function in your backend:

• Rust:

  use ic_cdk::api::caller;
  #[ic_cdk::query]
  fn whoami() -> String {
      let principal_id = caller().to_string();
      format!("principal id - : {:?}", principal_id)
  }
  

• Motoko:

  import Principal "mo:base/Principal";
  actor {
      public shared (msg) func whoami() : async Text {
          Principal.toText(msg.caller);
      };
  };
  

  For main-net you can use our canisterId as well: cni7b-uaaaa-aaaag-qc6ra-cai

3. For local or main-net middlePageCanisterId make sure you have the following:

• Local:

  Clone the repo from here and deploy locally: https://github.com/ICP-hub/flutter_icp_auth_middleware

• Main-net:

  a. You can deploy the cloned middlePage to main net and use the main net canister id.

  OR

  b. You can use our main-net id as well: nplfj-4yaaa-aaaag-qjucq-cai

4. For IDL and Services:

• You can use candid_dart to generate the did files and the IDL services and then use them in the app as demonstrated in the example app.

  OR

• You can add/write the file or code manually and then use them accordingly.

🚀 Getting Started & Usage

1. Setup

• Add these packages in pubspec.yaml:

  dependencies:
    flutter_icp_auth: ^1.0.0
    agent_dart: ^1.0.0-dev.22
  

• Import the packages in you main.dart:

  import 'package:agent_dart/agent_dart.dart';
  import 'package:flutter_icp_auth/flutter_icp_auth.dart';
  

• Configure Deep Linking in AndroidManifest.XML:

  Open android → app → src → main → AndroidManifest.XML, , add the following snippet, and replace android:scheme and android:host with your app's values:

  <meta-data android:name="flutter_deeplinking_enabled" android:value="true" />
              <intent-filter android:autoVerify="true">
                  <action android:name="android.intent.action.VIEW"/>
                  <category android:name="android.intent.category.DEFAULT"/>
                  <category android:name="android.intent.category.BROWSABLE" />
                  <data android:scheme="your_app_scheme" android:host="your_app_callback" />
                  <data android:scheme="https" />
              </intent-filter>
  

2. Initialization

• Declare your variables:

  bool isLocal =
      false; // To confirm if you running your project locally or using main-net. Change it to true if running locally
  Service idlService =
      FieldsMethod.idl; // Idl service (Location: lib/integration.dart)
  String backendCanisterId =
      'cni7b-uaaaa-aaaag-qc6ra-cai'; // Replace it with your backend canisterId
  String middlePageCanisterId =
      'nplfj-4yaaa-aaaag-qjucq-cai'; // Replace it with your middlePage canisterId
  

• Define the initState and dispose methods:

  @override
  void initState() {
    super.initState();
    AuthLogIn.checkLoginStatus(isLocal, backendCanisterId).then((loggedIn) {
      setState(() {
        isLoggedIn = loggedIn;
        if (loggedIn) {
          _principalId = AuthLogIn.getPrincipal;
        }
      });
      if (!loggedIn) {
        UrlListener.handleInitialUri(_fetchAgent, () {});
        UrlListener.initListener(_fetchAgent);
      }
    });
  }
  
  @override
  void dispose() {
    UrlListener.cancelListener();
    super.dispose();
  } 
  

• Manual login:

  isLoggedIn and _principalId are used to change the state of the log in/log out button and principal text. You can modify them according to your applications need.

  Future<void> _manualLogin(Uri uri) async {
    List<dynamic> result = await AuthLogIn.fetchAgent(
        uri.queryParameters, isLocal, backendCanisterId, idlService);
    if (result.isNotEmpty) {
      setState(() {
        isLoggedIn = uri.queryParameters['status'] == "true" ? true : false;
        _principalId = result[0];
      });
    } else {
      setState(() {
        isLoggedIn = false;
        _principalId = "Log in to see your principal";
      });
    }
  }
  

3. Using the IIDLogin Button

When passing argument in the IIDLogin button, remember to pass your app:host and app:callback:

For login button call:

Replace the argument host and scheme with your app's host and scheme

AuthLogIn.authenticate(isLocal, middlePageCanisterId, "exampleCallback", "example");

For logout button call:

List<Object> logoutValidation = await AuthLogout.logout(isLocal, backendCanisterId);

❗Troubleshooting

1. ZipFileEncoder.close and SingingBlockZipFileEncoder.close error:

• Go the agent_dart package location: agent_dart-1.0.0-dev.22/lib/archiver/encoder.dart:162:8

• Replace:

  void close() {
    _encoder.writeBlock(_output);
    _encoder.endEncode();
    _output.close();
  }
  

  with:

  Future<void> close() async{
  _encoder.writeBlock(_output);
  _encoder.endEncode();
  await _output.close();
  }
  

2. minSdkVersion error:

• Go the code location: example\android\app\build.gradle

• Change the minSdkVersion to 23

  defaultConfig {
      minSdkVersion 23
      targetSdkVersion flutter.targetSdkVersion
      versionCode flutterVersionCode.toInteger()
      versionName flutterVersionName
  }
  

ℹ️ Additional Info

📄 Example file location: example/lib/main.dart

This package depends on the following dependencies:

• agent_dart: ^1.0.0-dev.22
• flutter_custom_tabs: ^2.0.0+1
• flutter_secure_storage: ^9.2.1
• shared_preferences: ^2.2.3
• uni_links: ^0.5.1