FluentValidation - Validating a View Model that contains a list of an Object

Question

I am trying out FluentValidation on a project that contains complex view models and I read the documentation here but I don't see how to set up the rules to validate a list of objects declared in my view model. In my example below, the list in the view model contains 1 or more Guitar objects. Thanks

View Model

 [FluentValidation.Attributes.Validator(typeof(CustomerViewModelValidator))]
    public class CustomerViewModel
    {
        [Display(Name = "First Name")]
        public string FirstName { get; set; }

        [Display(Name = "Last Name")]
        public string LastName { get; set; }

        [Display(Name = "Phone")]
        public string Phone { get; set; }

        [Display(Name = "Email")]
        public string EmailAddress { get; set; }

        public List<Guitar> Guitars { get; set; } 
    }

Guitar class used in View Model

public class Guitar
{
    public string Make { get; set; }
    public string Model { get; set; }
    public int? ProductionYear { get; set; }
}

View Model Validator Class

 public class CustomerViewModelValidator : AbstractValidator<CustomerViewModel>
    {


        public CustomerViewModelValidator()
        {
            RuleFor(x => x.FirstName).NotNull();
            RuleFor(x => x.LastName).NotNull();
            RuleFor(x => x.Phone).NotNull();
            RuleFor(x => x.EmailAddress).NotNull();
           //Expects an indexed list of Guitars here????


        }
    }

Cant u have separete Validator for Guitar class?. What kind of validation u want on Ilist, is it to have more than one element? — Nitin Varpe, Jan 23 '14 at 13:47

score 83 · Answer 1 · edited Nov 09 '18 at 14:33

83

This code deprecated: RuleFor(x => x.Guitars).SetCollectionValidator(new GuitarValidator());

This is new:

RuleForEach(x => x.Guitars).SetValidator(new GuitarValidator());

edited Nov 09 '18 at 14:33

pushkin

9,575
15
51
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answered Nov 09 '18 at 14:25

1

This is very interesting – Reza Hashemi Feb 26 '20 at 22:24

score 71 · Accepted Answer · answered Jan 23 '14 at 13:52

You would add this to your CustomerViewModelValidator

RuleFor(x => x.Guitars).SetCollectionValidator(new GuitarValidator());

So your CustomerViewModelValidator would look like this:

public class CustomerViewModelValidator : AbstractValidator<CustomerViewModel>
{
    public CustomerViewModelValidator()
    {
        RuleFor(x => x.FirstName).NotNull();
        RuleFor(x => x.LastName).NotNull();
        RuleFor(x => x.Phone).NotNull();
        RuleFor(x => x.EmailAddress).NotNull();
        RuleFor(x => x.Guitars).SetCollectionValidator(new GuitarValidator());
    }
}

Add the GuitarValidator would look something like:

public class GuitarValidator : AbstractValidator<Guitar>
{
    public GuitarValidator()
    {
        // All your other validation rules for Guitar. eg.
        RuleFor(x => x.Make).NotNull();
    }
 }

SetCollectionValidator has been deprecated, use RuleForEach now. — rfcdejong, Oct 19 '18 at 11:54
Syntax for RuleForEach(x => x.Guitars).SetValidator(new GuitarValidator()); ref answer https://stackoverflow.com/a/53227565/193061 — Ram, Jan 21 '20 at 07:04

score 3 · Answer 3 · answered Jul 01 '19 at 14:01

3

RuleForEach(
  itemToValidate => 
     new YourObjectValidator());


public class YourObjectValidator : AbstractValidator<YourObject>
{
  public EdgeAPIAddressValidator()
  {
     RuleFor(r => r.YourProperty)
         .MaximumLenght(100);
  }
}

answered Jul 01 '19 at 14:01

Nico Campisano

179
1
4

4

Although this code snippet may answer the question, including an explanation of *why* and *how* it helps solve the problem improves the quality and longevity of your answer, especially regarding older questions like this one. See ["How do I write a good answer?"](https://stackoverflow.com/help/how-to-answer). – slothiful Jul 01 '19 at 15:25

score 3 · Answer 4 · edited Jan 07 '22 at 10:19

3

You can use childrule

RuleForEach(p => p.Guitars).ChildRules(child =>{
child.RuleFor(x=>x.Make).NotEmpty().WithMessage({PropertyName}required.") .NotNull(); });

edited Jan 07 '22 at 10:19

Elikill58

4,050
24
23
45

answered Jan 07 '22 at 09:45

Shankar Patil

31
1

score 1 · Answer 5 · answered Jul 01 '19 at 15:32

1

It works with the latest version of Fluent and contains a complete example to be used.

The code in the answer it's deprecated.

answered Jul 01 '19 at 15:32

Nico Campisano

179
1
4

FluentValidation - Validating a View Model that contains a list of an Object

5 Answers5

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