RzR.Validation.Attributes.AspNetCore 3.0.0.6710

RzR.Validation.Attributes.AspNetCore

ASP.NET Core integration for RzR.Validation.Attributes. It runs the DataAnnotations validation attributes automatically during request handling and turns failures into RFC 7807 problem responses.

Minimal APIs don't run DataAnnotations on bound parameters by themselves, and in MVC you end up writing the same ModelState-to-response glue in every action. This package covers both.

Install

dotnet add package RzR.Validation.Attributes.AspNetCore

It pulls in the core RzR.Validation.Attributes package. Targets net8.0 and references the ASP.NET Core shared framework.

Register

In Program.cs:

using RzR.Validation.Attributes.AspNetCore;

builder.Services.AddRzRValidation();

Everything is configurable through RzRValidationOptions:

using RzR.Validation.Attributes.AspNetCore;
using RzR.Validation.Attributes.AspNetCore.Options;

builder.Services.AddRzRValidation(options =>
{
    options.InvalidStatusCode = StatusCodes.Status422UnprocessableEntity; // default: 400
    options.ProblemTitle = "Validation failed";
    options.ProblemTypeUri = "https://example.com/errors/validation";
    options.MemberNameTransformer = name => char.ToLowerInvariant(name[0]) + name.Substring(1);
});

Minimal API

Decorate the model with the core attributes, then attach the filter to the endpoint:

using RzR.Validation.Attributes.Attributes.Require;
using RzR.Validation.Attributes.Attributes.Identity;
using RzR.Validation.Attributes.Attributes.Greater;
using RzR.Validation.Attributes.AspNetCore.Minimal;

public class CreateAccount
{
    [ValRequiredNotEmpty]
	
	public string Username { get; set; }
    [ValEmail]            
	public string Email { get; set; }
    
	[ValGreaterThan(0)]
	public decimal Balance { get; set; }
}

app.MapPost("/accounts", (CreateAccount account) => Results.Ok())
   .WithValidation<CreateAccount>();

Apply it to a whole route group instead of one endpoint:

var api = app.MapGroup("/api").WithValidation<CreateAccount>();

When the bound CreateAccount fails validation, the filter short-circuits before your handler runs and returns a problem response. A valid request passes straight through. The filter validates the first bound argument of type T.

MVC

MVC model binding already runs DataAnnotations and populates ModelState; here the filter's job is to standardize the failure response. Put [ValidateModel] on a controller or action:

using RzR.Validation.Attributes.AspNetCore.Mvc;

[ApiController]
[Route("accounts")]
public class AccountsController : ControllerBase
{
    [HttpPost]
    [ValidateModel]
    public IActionResult Create(CreateAccount account) => Ok();
}

Or register it for every action:

using RzR.Validation.Attributes.AspNetCore.Mvc;

builder.Services.AddControllers(options => options.Filters.Add<RzRValidateModelFilter>());

Response shape

Failures come back as application/problem+json (RFC 7807), keyed by member name:

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
  "title": "One or more validation errors occurred.",
  "status": 400,
  "errors": {
    "Email": ["The Email field must be a valid email address."],
    "Balance": ["The Balance field must be greater than 0."]
  }
}

Set the status with InvalidStatusCode, and reshape the keys (for example to camelCase) with MemberNameTransformer.

Notes

• Your models carry the rules — the core RzR.Validation.Attributes Val* attributes. This package triggers them; it doesn't define validation itself.
• On .NET 10+, the platform can run DataAnnotations on Minimal API parameters natively via AddValidation() / [ValidatableType]. Use whichever suits the project, but don't enable both on the same endpoint or you'll get duplicate errors.