Release notes

• Add support for ASP.NET Core 3.
• Add ASP.NET Core-compatible version of the email address validator.
• Simplify the advanced test-helper syntax.
• Add support for defining child rules inline when using RuleForEach.
• ValidatorDescriptor now has consistent handling of model-level rules.
• RuleForEach can now access collection index in error message with {CollectionIndex} placeholder.
• Welsh language translations of default error messages.
• Hungrian language translations of default error messages.
• Indonesian language translations of default error messages.
• Using RuleForEach combined with When has more intuitive behaviour.
• Fixed order of rule execution when using async validation.

Of these new features, the main one to note is the new ChildRules syntax. When defining a rule against a collection of complex types, rules for the child properties can be defined directly inline rather than having to use a child validator:

public class CustomerValidator : AbstractValidator<Customer> {
  public CustomerValidator() {
    RuleForEach(x => x.Orders).ChildRules(order => {
      order.RuleFor(x => x.ProductName).NotNull();
      order.RuleFor(x => x.Amount).GreaterThan(0);
    });
  }
}

Downloads

Binaries can be downloaded from nuget:

• FluentValidation - Main package
• FluentValidation.AspNetCore - ASP.NET Core integration
• FluentValidation.WebApi - Legacy ASP.NET Web Api 2 integration (deprecated)
• FluentValidation.Mvc5 - Legacy ASP.NET MVC 5 integration (deprecated)