chapter-organizer/WebApp/Components/Features/Students/Create.razor

@page "/students/create"
@attribute [Authorize]
@using WebApp.Components.Shared.Components
@using MudBlazor
@using WebApp.Services
@using Microsoft.EntityFrameworkCore
@inject AppDbContext Context
@inject NavigationManager NavigationManager
@inject ISnackbar Snackbar
@inject FormValidationService ValidationService

<PageHeader
    Title="Create"
    Subtitle="Student"
    ShowBackButton="true"
    BackButtonUrl="@(ReturnUrl ?? "/students")" />

<EditForm EditContext="@_editContext" OnValidSubmit="OnValidSubmit" OnInvalidSubmit="OnInvalidSubmit" Enhance>
    <FormChangeTracker @ref="_formChangeTracker" />
    <AntiforgeryToken />
    <DataAnnotationsValidator />
    
    <ValidationErrorDisplay Errors="_validationErrors" />

    <MudPaper Elevation="2" Class="pa-3 pa-md-6">
        <MudText Typo="Typo.h5" Class="mb-4">Student Information</MudText>
        <MudGrid Spacing="3">
            <MudItem xs="12" sm="6">
                <MudTextField T="string" Label="First Name" @bind-Value="Student.FirstName" For="@(() => Student.FirstName)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
            <MudItem xs="12" sm="6">
                <MudTextField T="string" Label="Last Name" @bind-Value="Student.LastName" For="@(() => Student.LastName)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
            <MudItem xs="12" sm="6">
                <MudTextField T="string" Label="Email Address" @bind-Value="Student.Email" For="@(() => Student.Email)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
            <MudItem xs="12" sm="6">
                <MudTextField T="string" Label="Phone Number" @bind-Value="Student.PhoneNumber" For="@(() => Student.PhoneNumber)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
            <MudItem xs="12" sm="6">
                <MudTextField T="int" Label="Grade" @bind-Value="Student.Grade" For="@(() => Student.Grade)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
            <MudItem xs="12" sm="6">
                <MudTextField T="int" Label="TSA Year" @bind-Value="Student.TsaYear" For="@(() => Student.TsaYear)" Variant="Variant.Outlined"></MudTextField>
            </MudItem>
        </MudGrid>

        <FormActions>
            <MudButton ButtonType="ButtonType.Submit" Variant="Variant.Filled" Color="Color.Primary">Create</MudButton>
            <MudButton OnClick="HandleCancel" Variant="Variant.Text">Cancel</MudButton>
        </FormActions>
    </MudPaper>
</EditForm>

@code {
    [SupplyParameterFromQuery]
    private string? ReturnUrl { get; set; }

    [SupplyParameterFromForm]
    private Student Student { get; set; } = new() { TsaYear = 1 };

    private FormChangeTracker? _formChangeTracker;
    private EditContext? _editContext;
    private List<string> _validationErrors = new();

    protected override void OnInitialized()
    {
        _editContext = new EditContext(Student);
    }

    private void OnInvalidSubmit(EditContext editContext)
    {
        _validationErrors = ValidationService.HandleInvalidSubmit(editContext, Student, errors => _validationErrors = errors);
        StateHasChanged();
    }

    private async Task OnValidSubmit()
    {
        _validationErrors.Clear();

        try
        {
            Context.Students.Add(Student);
            await Context.SaveChangesAsync();
            
            Snackbar.Add($"Student '{Student.FirstNameLastName}' created successfully.", Severity.Success);
            _formChangeTracker?.AllowNavigation();
            NavigationManager.NavigateTo(ReturnUrl ?? "/students");
        }
        catch (DbUpdateException ex)
        {
            ValidationService.HandleDbUpdateException(
                ex,
                "An error occurred while creating the student.",
                "student",
                "creating");
        }
        catch (Exception ex)
        {
            ValidationService.HandleException(ex);
        }
    }

    private void HandleCancel()
    {
        _formChangeTracker?.AllowNavigation();
        NavigationManager.NavigateTo(ReturnUrl ?? "/students");
    }
}