Error when I pass my object to validate equal null #795

2018-06-20T13:58:18Z

Hello everyone

I'm sorry I do not speak English and also if this channel is not considered appropriate for clarification of doubt. I am building a WebApi in .Net core 2.0 using version 7.5.2.

A validation that I must do is when my client that will consume my WebApi, should check if the object that arrived is null and for this I did the following validation

My validations

public class FaturaDtoValidator: AbstractValidator<FaturaDto>
   {
       public FaturaDtoValidator()
       {


           RuleFor(fatura => fatura).NotNull().WithMessage(Mensagem.FATURA_OBRIGATORIO);

           RuleFor(fatura => fatura.Itens).SetCollectionValidator(new ContratoItemDtoValidator());
           RuleFor(fatura => fatura.Itens).NotNull().WithMessage(Mensagem.ITENS_OBRIGATORIO);
           RuleFor(fatura => fatura.Itens).Must(list => list.Count == 0).WithMessage(Mensagem.ITENS_OBRIGATORIO);


       }
   }

public class ContratoItemDtoValidator : AbstractValidator<ContratoItemDto>
    {
        public ContratoItemDtoValidator()
        {
            RuleFor(item => item.CodigoItem).NotEmpty().NotNull().WithMessage(Mensagem.CODIGO_ITEM_OBRIGATORIO);
        }
    }

My startup class

    services
                .AddTransient<IValidator<FaturaDto>, FaturaDtoValidator>()
                .AddTransient<IValidator<ContratoItemDto>, ContratoItemDtoValidator>();

Meu controller (My controller)

 [Produces("application/json")]
    [Route("api/v1/")]
    public class HubController : Controller
    {

        [HttpPost("{fatura}")]
        [Route("faturamento")]
        public async Task<IActionResult> Faturamento([FromBody]FaturaDto fatura)
        {
            
            OrchestratorApp orc = new OrchestratorApp();
            return await orc.RedirectFaturamento(fatura);
        }
    }

And to trigger validation

 public async Task<JsonResult> RedirectFaturamento(FaturaDto fatura)
        {
          ...
            FaturaDtoValidator validator = new FaturaDtoValidator();
            ValidationResult results = validator.Validate(fatura);

codigo

My FaturaDto object came null and it is this test I would like to include but when the validation is triggered an error occurs "ArgumentNullException: Value can not be null. Parameter name: Can not pass null model to Validate."

erro

The text was updated successfully, but these errors were encountered:

2018-06-20T13:59:49Z

Hi there, please could you post your question in English?

Looking at the screenshot, you must provide a non-null root instance. This is by design.

2018-06-20T14:05:13Z

Hi Jeremy thanks for answering, I'm using google translator

2018-06-20T14:06:54Z

Is there a possibility, to include in the library to see this validation, when it comes to object null?

2018-06-20T14:12:01Z

No, that's not possible I'm afraid - FluentValidation is designed to validate properties on a non-null object instance. You can't pass a null instance to Validate. You need to make sure that WebApi instantiates a valid instance before passing it to the validator.

2018-06-20T14:19:15Z

Is this also true for an instantiated object that contains a null list?
This list should also be instantiated?

I can do something about it:
RuleFor(fatura => fatura.Itens).NotNull().WithMessage(Mensagem.ITENS_OBRIGATORIO);
RuleFor(fatura => fatura.Itens).Must(list => list.Count ==0).WithMessage(Mensagem.ITENS_OBRIGATORIO);

2018-06-20T14:24:38Z

That's fine, the list can be null, but you should put a When condition on the second rule, like this:

RuleFor(fatura => fatura.Itens).NotNull().WithMessage(Mensagem.ITENS_OBRIGATORIO);
RuleFor(fatura => fatura.Itens).Must(list => list.Count ==0).WithMessage(Mensagem.ITENS_OBRIGATORIO).When(list => list != null);

2018-06-20T14:25:37Z

Or you could combine them into a single rule and use the CascadeMode to stop the second rule from executing:

RuleFor(fatura => fatura.Itens)
  .Cascade(CascadeMode.StopOnFirstFailure)
  .NotNull().WithMessage(Mensagem.ITENS_OBRIGATORIO)
  .Must(list => list.Count ==0).WithMessage(Mensagem.ITENS_OBRIGATORIO);

2018-06-20T14:36:34Z

I understood the explanation and thank you for your time.

2018-06-20T14:37:18Z

You're welcome - let me know if you have any other questions.

raffaelmiranda closed this as completed Jun 20, 2018

raffaelmiranda reopened this Jun 20, 2018

JeremySkinner closed this as completed Jun 20, 2018

lock bot locked and limited conversation to collaborators Aug 20, 2018

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Error when I pass my object to validate equal null #795

Error when I pass my object to validate equal null #795

raffaelmiranda commented Jun 20, 2018 •

edited

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018 •

edited

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

Error when I pass my object to validate equal null #795

Error when I pass my object to validate equal null #795

Comments

raffaelmiranda commented Jun 20, 2018 • edited

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018 • edited

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018

JeremySkinner commented Jun 20, 2018

raffaelmiranda commented Jun 20, 2018 •

edited

raffaelmiranda commented Jun 20, 2018 •

edited