Flutter Easy Login

An Easy and Simple UI for Authentication.

• Login with email and password.
• Register with Email, Name and Password.
• Password reset.
• Works with Firebase or your Authentication Service.

Features

Usage

Implementation of this easy.

• First in the main() method add this statement("WidgetsFlutterBinding.ensureInitialized();") at the start.
• If you are using firebase then initialize firebase("await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);").
• Then in the runApp() method create the AuthenticationProvider passing the method "initializeLoginState()" in its constructor.

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
  runApp(ChangeNotifierProvider(create: (context) => AuthenticationProvider(
      FirebaseManageUsers.listenToFirebaseAuthStateChanges
  ),
    child: const MyApp(),));
}

** FirebaseManageUser is a class that has all the required implementations for firebase auth **

• If you are not using Firebase then no need to initialize Firebase
• but in the AuthenticationProvider constructor need to pass the method "initializeLoginState" that has the parameter of AuthenticationProvider
• and that checks for the login state then update the authState field in the AuthenticationProvider to appropriate State

void initializeLoginState(AuthenticationProvider authProvider){
  bool isLoggedIn = checkUserIsLoggedInOrNot();
  if(isLoggedIn){
    authProvider.authState = AuthState.loggedIn;
    authProvider.userName = userName;//optional
    authProvider.email = email;//optional
    authProvider.notify();
  }else {
    authProvider.email = null; //optional
    authProvider.authState = AuthState.loggedOut;
    authProvider.notify();
  }
}

• After the above implementation you need to use LoginPage widget as the first screen and need to pass all the required arguments as mentioned below:
  • appName: The Name Of Your App to show in all login, Register pages
  • child: The First screen user will see if logged in
  • passwordRegex: The Regex pattern that password must meet i.e password pattern
  • invalidPasswordMessage: A message to be displayed to the user when the password does not match with passwordRegex this should not be null if passwordRequirements is null and vice versa. If want to show simple one message use this or use passwordRequirements to display particular message
  • passwordRequirements: A map containing pairs of regex of Each password requirements and message to display e.g {r'(?=.0-9).' : "Password must contains at least one digit"}. This map is used to display particular messages of invalid password. if this is null then invalidPasswordMessage should not be null and vice versa.
  • isUsingFirebaseAuth: Tells should use default FirebaseAuth auth methods for login, checkEmail, register, sendPasswordResetEmail, logout. By default it is false. If it is true then no need to provide authentication methods, if it false then need to provide all the authentication methods for login, checkEmail, register, sendPasswordResetEmail, logout.
  • checkEmail: If isUsingFirebaseAuth is true then default FirebaseAuth.fetchSignInMethodsForEmail will be used. Other wise need to provide this method. The function that accepts an email and checks the email and returns true if the user is already exists with the email, otherwise returns false if the user is new. AuthenticationProvider is used to update the widget to password widget if user is exists with the email. And if there is any thing wrong in email then assign appropriate AuthExceptionType to the AuthenticationProvider.authExceptionType
  • login: If isUsingFirebaseAuth is true then default FirebaseAuth.signInWithEmailAndPassword will be used. Other wise need to provide this method. The function that accepts email and password and return true if the email and password are valid and let user login other wise return false. And if email and password does not match or any thing wrong in email or password then assign appropriate AuthExceptionType to the AuthenticationProvider.authExceptionType
  • register: If isUsingFirebaseAuth is true then default FirebaseAuth.createUserWithEmailAndPassword will be used. Other wise need to provide this method. The function that accepts email, password and name and create an account with the provided details. If any error is there then need to assign appropriate AuthExceptionType to the AuthenticationProvider.authExceptionType
  • sendPasswordResetEmail: If isUsingFirebaseAuth is true then default FirebaseAuth.sendPasswordResetEmail will be used. Other wise need to provide this method. The function that accepts an email and sends a password reset email to the provided email. Returns true if the password reset email sends successfully otherwise returns false. If any error is there then need to assign appropriate AuthExceptionType to the AuthenticationProvider.authExceptionType
  • signOut: If isUsingFirebaseAuth is true then default FirebaseAuth.signOut will be used. Other wise need to provide this method. The function that sign out the user. If any error is there then need to assign appropriate AuthExceptionType to the AuthenticationProvider.authExceptionType
• Example for one Authentication method:

    Future<bool> checkEmail(String email, AuthenticationProvider authProvider)async{
    bool isAccountExists = false;
    try{
      isAccountExists = await doesAnyAccountExistWithThisEmail(email);
    }on FirebaseAuthException catch(e){
      authProvider.authExceptionType = AuthExceptions.typeOf[e.code];
    }catch (e) {
      printToConsole("Exception in FirebaseManageUsers.loginWithEmailPassword: ${e.toString()}");
      authProvider.authExceptionType = AuthExceptionType.unknown;
    }
    return isAccountExists;
  }

• Note: Check for console while running flutter app in debug mode for any Exceptions if any functionality is not working.