在没有包装对象的情况下使用 FluentValidation 验证对象列表的最佳方法

Question

FluentValidation has the possibility to validate collections as described in the documentation . However all the examples speak of collections inside an object like:

public class Person 
{
  public List<string> AddressLines { get; set; } = new List<string>();
}

I am wondering what the best way is to validate a List<Person> when the collection is not inside an object:

public List<Person> GetPersonsAndValidate()
{
    List<Person> persons = GetPersons();
    // Perform validation
    // Do something with the validation
    return persons;
}

or in a ASP.NET Core controller:

[HttpPost]
public IActionResult DoSomething(List<Person> persons)
{
    if (!ModelState.IsValid)
    {
        // Do something with the invalid model, but is it validated?
    }
}

I see two options here, where the second option is not suitable for the second example:

1. Create a validator on IEnumerable<Person> like:

public class PersonsValidator : AbstractValidator<IEnumerable<Person>>
{
    public PersonsValidator()
    {
        RuleForEach(x => x).SetValidator(new PersonValidator());
    }

}

2. Call the person validator directly by looping over the list:

foreach (var person in persons)
{
    // I know, the creation of the validator can go outside the foreach...
    var result = new PersonValidator().Validate(person);
    // do something with the result
}

3. Wrap it inside a parent object anyways (which then needs a validator as well...)

Are these the only options, or are there other ways to do this?

Answer 1

If you set the property ImplicityValidateChildProperties to true in the fluent validation configuration that should do it.

        services
            .AddControllers()
            .AddFluentValidation(
                config =>
                {
                    config.AutomaticValidationEnabled = true;
                    config.ImplicitlyValidateChildProperties = true;
                    config.ValidatorOptions.CascadeMode = CascadeMode.Continue;
                })
            .AddNewtonsoftJson();

This automatically validates children properties which in this case is each Person object within the collection. I know this works with ICollection but have not tested it with Arrays.