BlazorSignalStore: Una forma sencilla de gestionar el estado en Blazor

builder.Services.AddScoped<ContainerStateService>();

public record FormContainerState
    {
        public PersonalInfo PersonalInfo { get; init; } = new();
        public Address Address { get; init; } = new();
        public UserPreferencesData Preferences { get; init; } = new();
        public bool IsSubmitting { get; init; } = false;
        public SubmissionResult? SubmissionResult { get; init; } = null;

        // Lógica de validación dentro del contenedor
        public bool IsValid()
        {
            return PersonalInfo.IsValid() && Address.IsValid() && Preferences.IsValid();
        }

        public bool CanSubmit()
        {
            return IsValid() && !IsSubmitting;
        }

        public List<string> GetValidationErrors()
        {
            var errors = new List<string>();
            errors.AddRange(PersonalInfo.GetValidationErrors());
            errors.AddRange(Address.GetValidationErrors());
            errors.AddRange(Preferences.GetValidationErrors());
            return errors;
        }

        public double GetCompletionPercentage()
        {
            var totalFields = 9; // Total de campos requeridos
            var completedFields = 0;

            if (!string.IsNullOrWhiteSpace(PersonalInfo.FirstName)) completedFields++;
            if (!string.IsNullOrWhiteSpace(PersonalInfo.LastName)) completedFields++;
            if (!string.IsNullOrWhiteSpace(PersonalInfo.Email)) completedFields++;
            if (!string.IsNullOrWhiteSpace(Address.Street)) completedFields++;
            if (!string.IsNullOrWhiteSpace(Address.City)) completedFields++;
            if (!string.IsNullOrWhiteSpace(Address.PostalCode)) completedFields++;
            if (!string.IsNullOrWhiteSpace(Address.Country)) completedFields++;
            if (!string.IsNullOrWhiteSpace(Preferences.Theme)) completedFields++;
            if (Preferences.EmailNotifications || Preferences.SmsNotifications) completedFields++;

            return (double)completedFields / totalFields * 100;
        }
    }

    public class ContainerStateService
    {
        private FormContainerState _formState = new();

        public event Action? OnChange;

        public FormContainerState FormState => _formState;

        // Propiedades derivadas del estado del contenedor
        public bool IsFormValid => _formState.IsValid();
        public bool CanSubmit => _formState.CanSubmit();
        public List<string> ValidationErrors => _formState.GetValidationErrors();
        public double FormCompletionPercentage => _formState.GetCompletionPercentage();

        // Acciones que modifican el estado del contenedor
        public void UpdatePersonalInfo(string firstName, string lastName, string email)
        {
            _formState = _formState with
            {
                PersonalInfo = _formState.PersonalInfo with
                {
                    FirstName = firstName,
                    LastName = lastName,
                    Email = email
                }
            };
            NotifyStateChanged();
        }

        public void UpdateAddress(string street, string city, string postalCode, string country)
        {
            _formState = _formState with
            {
                Address = _formState.Address with
                {
                    Street = street,
                    City = city,
                    PostalCode = postalCode,
                    Country = country
                }
            };
            NotifyStateChanged();
        }

        public void UpdatePreferences(bool emailNotifications, bool smsNotifications, string theme)
        {
            _formState = _formState with
            {
                Preferences = _formState.Preferences with
                {
                    EmailNotifications = emailNotifications,
                    SmsNotifications = smsNotifications,
                    Theme = theme
                }
            };
            NotifyStateChanged();
        }

        private void NotifyStateChanged() => OnChange?.Invoke();
    }

builder.Services.AddSignalStore<SignalFormStore>();

using BlazorSignalStore.Core;

namespace BlazorSignalStore.Demo.Store
{
    /// <summary>
    /// Un store de formulario demostrando reactividad granular con Signals.
    /// Cada propiedad es su propio Signal, permitiendo actualizaciones precisas de la UI.
    /// </summary>
    public class SignalFormStore : StoreBase
    {
        // Signals de Información Personal
        public Signal<string> FirstName { get; } = new("");
        public Signal<string> LastName { get; } = new("");
        public Signal<string> Email { get; } = new("");

        // Signals de Dirección
        public Signal<string> Street { get; } = new("");
        public Signal<string> City { get; } = new("");
        public Signal<string> PostalCode { get; } = new("");
        public Signal<string> Country { get; } = new("");

        // Signals de Preferencias
        public Signal<bool> EmailNotifications { get; } = new(false);
        public Signal<bool> SmsNotifications { get; } = new(false);
        public Signal<string> Theme { get; } = new("light");

        // Propiedades computadas para validación y progreso
        public Computed<bool> IsPersonalInfoValid { get; }
        public Computed<bool> IsAddressValid { get; }
        public Computed<bool> IsFormValid { get; }
        public Computed<double> FormProgress { get; }

        public SignalFormStore()
        {
            IsPersonalInfoValid = new Computed<bool>(() =>
                !string.IsNullOrWhiteSpace(FirstName.Value) &&
                !string.IsNullOrWhiteSpace(LastName.Value) &&
                !string.IsNullOrWhiteSpace(Email.Value),
                FirstName, LastName, Email);

            IsAddressValid = new Computed<bool>(() =>
                !string.IsNullOrWhiteSpace(Street.Value) &&
                !string.IsNullOrWhiteSpace(City.Value) &&
                !string.IsNullOrWhiteSpace(PostalCode.Value) &&
                !string.IsNullOrWhiteSpace(Country.Value),
                Street, City, PostalCode, Country);

            IsFormValid = new Computed<bool>(() =>
                IsPersonalInfoValid.Value && IsAddressValid.Value,
                IsPersonalInfoValid, IsAddressValid);

            FormProgress = new Computed<double>(() =>
            {
                var completedFields = 0;
                var totalFields = 9;

                if (!string.IsNullOrWhiteSpace(FirstName.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(LastName.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(Email.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(Street.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(City.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(PostalCode.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(Country.Value)) completedFields++;
                if (!string.IsNullOrWhiteSpace(Theme.Value)) completedFields++;
                if (EmailNotifications.Value || SmsNotifications.Value) completedFields++;

                return (double)completedFields / totalFields * 100;
            }, FirstName, LastName, Email, Street, City, PostalCode, Country, Theme, EmailNotifications, SmsNotifications);
        }
    }
}