fullstack-classic

Classic Fullstack Integration Patterns

Form Handling

Server-Side Form Processing

// Controller
public class ContactController : Controller
{
    private readonly IContactService _contactService;
    private readonly ILogger<ContactController> _logger;

    public ContactController(
        IContactService contactService,
        ILogger<ContactController> logger)
    {
        _contactService = contactService;
        _logger = logger;
    }

    [HttpGet]
    public IActionResult Index()
    {
        return View(new ContactFormModel());
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Index(ContactFormModel model, CancellationToken ct)
    {
        if (!ModelState.IsValid)
        {
            return View(model);
        }

        try
        {
            await _contactService.ProcessContactAsync(model, ct);
            TempData["SuccessMessage"] = "Thank you for your message!";
            return RedirectToAction(nameof(Index));
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to process contact form");
            ModelState.AddModelError("", "An error occurred. Please try again.");
            return View(model);
        }
    }
}

Razor Form

@model ContactFormModel

@if (TempData["SuccessMessage"] != null)
{
    <div class="alert alert-success">
        @TempData["SuccessMessage"]
    </div>
}

<form asp-action="Index" method="post">
    @Html.AntiForgeryToken()
    
    <div asp-validation-summary="ModelOnly" class="text-danger"></div>
    
    <div class="form-group">
        <label asp-for="Name"></label>
        <input asp-for="Name" class="form-control" />
        <span asp-validation-for="Name" class="text-danger"></span>
    </div>
    
    <div class="form-group">
        <label asp-for="Email"></label>
        <input asp-for="Email" class="form-control" type="email" />
        <span asp-validation-for="Email" class="text-danger"></span>
    </div>
    
    <div class="form-group">
        <label asp-for="Message"></label>
        <textarea asp-for="Message" class="form-control" rows="5"></textarea>
        <span asp-validation-for="Message" class="text-danger"></span>
    </div>
    
    <button type="submit" class="btn btn-primary">Send Message</button>
</form>

@section Scripts {
    <partial name="_ValidationScriptsPartial" />
}