Below is a simplified version of my problem.
I can not flatten the model. There is a List of "children" that I need to validate a birthday.
I can not seem to reference the date in the Parent class and was wondering how this is done in Fluent Validation?
Model
[Validator(typeof(ParentValidator))]
public class Parent
{
public string Name { get; set; }
public DateTime Birthdate { get; set; }
public List<Child> Children { get; set; }
}
public class Child
{
public string ChildProperty{ get; set; }
public DateTime Birthdate { get; set; }
}
Validator
public class ParentValidator : AbstractValidator<Parent>
{
public ParentValidator()
{
RuleFor(model => model.Name).NotEmpty();
RuleForEach(model => model.Children).SetValidator(new ChildValidator());
}
}
public class ChildValidator : AbstractValidator<Child>
{
public ChildValidator()
{
RuleFor(model => model.ChildProperty).NotEmpty();
//Compare birthday to make sure date is < Parents birthday
}
}
Create a custom property validator like this
public class AllChildBirtdaysMustBeLaterThanParent : PropertyValidator
{
public AllChildBirtdaysMustBeLaterThanParent()
: base("Property {PropertyName} contains children born before their parent!")
{
}
protected override bool IsValid(PropertyValidatorContext context)
{
var parent = context.ParentContext.InstanceToValidate as Parent;
var list = context.PropertyValue as IList<Child>;
if (list != null)
{
return ! (list.Any(c => parent.BirthDay > c.BirthDay));
}
return true;
}
}
Add rules like this
public class ParentValidator : AbstractValidator<Parent>
{
public ParentValidator()
{
RuleFor(model => model.Name).NotEmpty();
RuleFor(model => model.Children)
.SetValidator(new AllChildBirtdaysMustBeLaterThanParent());
// Collection validator
RuleFor(model => model.Children).SetCollectionValidator(new ChildValidator());
}
}
Alternative to the Custom Property validator is to use the Custom method:
public ParentValidator()
{
RuleFor(model => model.Name).NotEmpty();
RuleFor(model => model.Children).SetCollectionValidator(new ChildValidator());
Custom(parent =>
{
if (parent.Children == null)
return null;
return parent.Children.Any(c => parent.BirthDay > c.BirthDay)
? new ValidationFailure("Children", "Child cannot be older than parent.")
: null;
});
}
Crude way of showing indicies that failed: (should probably be name of some other identifier)
public class ParentValidator : AbstractValidator<Parent>
{
public ParentValidator()
{
RuleFor(m => m.Children).SetCollectionValidator(new ChildValidator());
Custom(parent =>
{
if (parent.Children == null)
return null;
var failIdx = parent.Children.Where(c => parent.BirthDay > c.BirthDay).Select(c => parent.Children.IndexOf(c));
var failList = string.Join(",", failIdx);
return failIdx.Count() > 0
? new ValidationFailure("Children", "Child cannot be older than parent. Fail on indicies " + failList)
: null;
});
}
}