Add a factory method for creating the CompositeValidatorSelector

Is your feature request related to a problem? Please describe.

When defining a RuleSet along with properties to be validated (like described here) the ValidationStrategy builds a CompositeValidatorSelector which then uses Any to combine IValidatorSelectors.

There are cases where it would be feasible to change Any to All since a RuleSet might define other rules for a property or there is no need to run validators not defined in a RuleSet using an explicit property. Currently that is not possible.

Describe the solution you’d like

Something like this:

public enum ValidatorSelectorCombineMode
{
    All,
    Any,
}

When set to All the above described case will be possible. Any is the currently default method to keep backward compatibility.

Describe alternatives you’ve considered

I’m willing to make a PR if this addition is welcome.

Additional Context

A sample which describes when to use this feature:

internal class ClientDetailsModelValidator : AbstractValidator<Models.ClientDetails>
{
    public ClientDetailsModelValidator()
    {
        RuleSet("name", () =>
        {
            RuleFor(m => m.Surname)
                .NotEmpty()
                .MaximumLength(50)
            ;

            RuleFor(m => m.Name)
                .NotEmpty()
                .MaximumLength(50)
            ;

            RuleFor(m => m.Patronymic)
                .MaximumLength(50)
            ;
        });

        RuleFor(m => m.Sex)
            .NotEmpty()
        ;

        RuleFor(m => m.Birthday)
            .NotEmpty()
            .LessThanOrEqualTo(DateTime.Today)
            .ExclusiveBetween(new DateTime(1900, 01, 01), new DateTime(2100, 01, 01))
        ;
    }
}

Currently it’s not possible to validate a Surname property from name RuleSet separately. Or at least I haven’t found a way for it to work in a single Validate call.

[uhfath]

Currently it’s not possible to validate a Surname property from name RuleSet separately. Or at least I haven’t found a way for it to work in a single Validate call.

What does the validate call look like @uhfath ? Just curious about the use case here.

Something along the lines:

private ValidationContext<object> BuildValidationContext(object model, params string[] properties) =>
    ValidationContext<object>.CreateWithOptions(model, opts =>
    {
        if (!properties.IsEmpty())
        {
            opts.IncludeProperties(properties);
        }

        if (!string.IsNullOrWhiteSpace(RuleSet))
        {
            opts.IncludeRuleSets(RuleSet);
        }

        if (!RuleSets.IsEmpty())
        {
            opts.IncludeRuleSets(RuleSets.ToArray());
        }

        if (UseNotInRuleSet)
        {
            opts.IncludeRulesNotInRuleSet();
        }

        opts.SetSelectorCombineMode(FluentValidation.Internal.ValidatorSelectorCombineMode.All);
    });

//---------------------------

    var property = eventArgs.FieldIdentifier.FieldName;
    var context = BuildValidationContext(eventArgs.FieldIdentifier.Model, property);
    var validator = (IValidator)ServiceProvider.GetRequiredService(MakeValidatorType(eventArgs.FieldIdentifier.Model.GetType()));
    var result = validator.Validate(context);

[JeremySkinner]

I’ve pushed out an 11.2 release which contains the ValidatorOptions.Global.ValidatorSelectors.CompositeValidatorSelectorFactory