The getter 'isSubmissionFailure' isn't defined for the type 'FormzSta…

…tus'.

Try importing the library that defines 'isSubmissionFailure', correcting the name to the name of an existing getter, or defining a getter or field named 'isSubmissionFailure'

lib/login/bloc/login_bloc.dart

@@ -0,0 +1,69 @@
+import 'dart:async';
+
+import 'package:authentication_repository/authentication_repository.dart';
+import 'package:bloc/bloc.dart';
+import 'package:bloc_complete_practice/login/models/models.dart';
+import 'package:equatable/equatable.dart';
+import 'package:formz/formz.dart';
+
+part 'login_event.dart';
+part 'login_state.dart';
+
+class LoginBloc extends Bloc<LoginEvent, LoginState> {
+  final AuthenticationRepository _authenticationRepository;
+
+  LoginBloc({
+    required AuthenticationRepository authenticationRepository,
+  })   : _authenticationRepository = authenticationRepository,
+        super(const LoginState());
+
+  @override
+  Stream<LoginState> mapEventToState(
+    LoginEvent event,
+  ) async* {
+    if (event is LoginUsernameChanged) {
+      yield _mapLoginUsernameChangedToState(event, state);
+    } else if (event is LoginPasswordChanged) {
+      yield _mapLoginPasswordChangedToState(event, state);
+    } else if (event is LoginFormSubmitted) {
+      yield* _mapLoginFormSubmittedToState(event, state);
+    }
+  }
+
+  LoginState _mapLoginUsernameChangedToState(
+    LoginUsernameChanged event,
+    LoginState state,
+  ) {
+    final username = Username.dirty(event.username);
+    return state.copyWith(
+        username: username, status: Formz.validate([username, state.password]));
+  }
+
+  LoginState _mapLoginPasswordChangedToState(
+    LoginPasswordChanged event,
+    LoginState state,
+  ) {
+    final password = Password.dirty(event.password);
+    return state.copyWith(
+        password: password, status: Formz.validate([password, state.username]));
+  }
+
+  Stream<LoginState> _mapLoginFormSubmittedToState(
+    LoginFormSubmitted event,
+    LoginState state,
+  ) async* {
+    if (state.status.isValidated) {
+      yield state.copyWith(status: FormzStatus.submissionInProgress);
+      try {
+        await _authenticationRepository.logIn(
+          username: state.username.value,
+          password: state.password.value,
+        );
+        yield state.copyWith(status: FormzStatus.submissionSuccess);
+      } catch (e) {
+        print(e.toString());
+        yield state.copyWith(status: FormzStatus.submissionFailure);
+      }
+    }
+  }
+}

lib/login/bloc/login_event.dart

@@ -0,0 +1,30 @@
+part of 'login_bloc.dart';
+
+abstract class LoginEvent extends Equatable {
+  const LoginEvent();
+
+  @override
+  List<Object> get props => [];
+}
+
+class LoginUsernameChanged extends LoginEvent {
+  final String username;
+
+  const LoginUsernameChanged(this.username);
+
+  @override
+  List<Object> get props => [username];
+}
+
+class LoginPasswordChanged extends LoginEvent {
+  final String password;
+
+  const LoginPasswordChanged(this.password);
+
+  @override
+  List<Object> get props => [password];
+}
+
+class LoginFormSubmitted extends LoginEvent {
+  const LoginFormSubmitted();
+}

lib/login/bloc/login_state.dart

@@ -0,0 +1,30 @@
+part of 'login_bloc.dart';
+
+class LoginState extends Equatable {
+  const LoginState({
+    this.status = FormzStatus.pure,
+    this.username = const Username.pure(),
+    this.password = const Password.pure(),
+  });
+
+  final FormzStatus status;
+  final Username username;
+  final Password password;
+
+  LoginState copyWith({
+    FormzStatus? status,
+    Username? username,
+    Password? password,
+  }) {
+    return LoginState(
+      status: status ?? this.status,
+      username: username ?? this.username,
+      password: password ?? this.password,
+    );
+  }
+
+  @override
+  List<Object> get props => [status, username, password];
+}
+
+class LoginInitial extends LoginState {}

lib/login/models/models.dart

@@ -0,0 +1,2 @@
+export 'password.dart';
+export 'username.dart';

lib/login/models/password.dart

@@ -0,0 +1,13 @@
+import 'package:formz/formz.dart';
+
+enum PasswordValidationError { empty }
+
+class Password extends FormzInput<String, PasswordValidationError> {
+  const Password.pure() : super.pure('');
+  const Password.dirty([String value = '']) : super.dirty(value);
+
+  @override
+  PasswordValidationError? validator(String? value) {
+    return value?.isNotEmpty == true ? null : PasswordValidationError.empty;
+  }
+}

lib/login/models/username.dart

@@ -0,0 +1,13 @@
+import 'package:formz/formz.dart';
+
+enum UsernameValidationError { empty }
+
+class Username extends FormzInput<String, UsernameValidationError> {
+  const Username.pure() : super.pure('');
+  const Username.dirty([String value = '']) : super.dirty(value);
+
+  @override
+  UsernameValidationError? validator(String? value) {
+    return value?.isNotEmpty == true ? null : UsernameValidationError.empty;
+  }
+}

lib/login/view/login_form.dart

@@ -0,0 +1,18 @@
+import 'package:bloc_complete_practice/login/bloc/login_bloc.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+/*
+ * The LoginForm handles notifying the LoginBloc of user events and 
+ * also responds to state changes using BlocBuilder and BlocListener.
+ */
+class LoginForm extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return BlocListener<LoginBloc, LoginState>(
+      listener: (context, state) {
+        if (state.status.isSubmissionFailure) {}
+      },
+    );
+  }
+}

lib/login/view/login_page.dart

@@ -0,0 +1,35 @@
+import 'package:authentication_repository/authentication_repository.dart';
+import 'package:bloc_complete_practice/login/bloc/login_bloc.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import 'login_form.dart';
+
+/*
+ * The LoginPage is responsible for exposing the Route as well as 
+ * creating and providing the LoginBloc to the LoginForm
+ */
+class LoginPage extends StatelessWidget {
+  static Route<void> route() {
+    return MaterialPageRoute(
+      builder: (context) {
+        return LoginPage();
+      },
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text("Login")),
+      body: BlocProvider(
+        create: (context) {
+          return LoginBloc(
+              authenticationRepository:
+                  RepositoryProvider.of<AuthenticationRepository>(context));
+        },
+        child: LoginForm(),
+      ),
+    );
+  }
+}