FluentValidation ASP.NET Core. Can't to validate IFormFile

Question

I have a model

[AutoMap(typeof(WorkDTO), ReverseMap = true)]
public class WorkDTO
{
  public Guid Id { get; set; }
  public string UserId { get; set; }
  public string Name { get; set; }
  public string AvaUrl { get; set; }
  public List<IFormFile> AvaWork { get; set; }
}

I have FluentValidator which is configured for this model.

public WorkDtoValidator()
{
    RuleFor(p => p.Name)
        .NotNull()
        .NotEmpty()
        .Length(2, 50)
        .WithMessage("{PropertyName} should be not empty.");
    RuleFor(p => p.Description)
        .NotNull()
        .NotEmpty()
        .Length(50, 1000)
        .WithMessage("{PropertyName} should be not empty.");
    RuleFor(x => x.AvaWork).NotEmpty();
}

And configured it in StartUp

services.AddControllers()
            .AddFluentValidation();
services.AddSingleton<IValidator<WorkDTO>, WorkDtoValidator>();

Validation work normal, but if I don`t send property AvaWork. If in model comes AvaWork than I get an exception

I tried without RuleFor(x => x.AvaWork).NotEmpty(); The same result. I Have a special validation class for validation AvaWork.

public class FileValidator : AbstractValidator<IFormFile>
{
    public FileValidator()
    {
        RuleFor(x => x.Length).NotNull().LessThanOrEqualTo(100)
            .WithMessage("File size is larger than allowed");

        RuleFor(x => x.ContentType).NotNull().Must(x => x.Equals("image/jpeg") || 
        x.Equals("image/jpg") || x.Equals("image/png"))
            .WithMessage("File type is larger than allowed");
    }
}

And added this line RuleForEach(x => x.AvaWork ).SetValidator(new FileValidator()); The same result.

If in controller will be only List<IFormFile> AvaWork (not model public async Task<IActionResult> CreateWork(WorkDTO model)) It works good.

I don`t have any ideas.

Answer 1

The problem was in both sides. In front(Angular 11 - Typescript) I need add all properties to formData. By this way

const formData = new FormData();
formData.append('Name', this.createWorkForm.get('Name').value);
formData.append('Description', this.createWorkForm.get('description').value);


this.WorkMarkets.forEach(market => {
  formData.append('Markets', market);
});

this.WorkingHours.forEach(session => {
  formData.append('WorkingHours', session);
});

if (this.fileToUploadMain != null) {
  formData.append('AvaWork', this.fileToUploadMain, this.fileToUploadMain.name);
}

this.apiWorkService.createWork(formData).subscribe(
  suc => {
    console.log(suc);
  },
  err => {
    console.log(err);
  });

And in back side add [FromForm] in Controller param

public async Task<IActionResult> CreateWork([FromForm]WorkDTO formWork)

Model of WorkDTO

public class WorkDTO
{
    public Guid Id { get; set; }
    public string UserId { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public IEnumerable<string> WorkingHours { get; set; }
    public IEnumerable<string> Markets { get; set; }
    public string AvaUrl { get; set; }
    public IFormFile AvaWork { get; set; }
}