Validate 2 lists using FluentValidation

Question

if anyone has much experience using [C#] FluentValidation and has any ideas for the below question any help would be much appreciated.

I have 2 Generic Lists (both with

Answer 1

I ended up using the following FluentValidation code to check the corrosponding items in each list, big thanks to Guvante as it was inspired by his Pseudo-code :)

RuleFor(f => f.Names).Must((f, d) =>
            {
                for (int i = 0; i < d.Count; i++)
                {
                    if ((String.IsNullOrEmpty(d[i]) &&
                         !String.IsNullOrEmpty(f.URLs[i])))
                        return false;
                }

                return true;
            })
            .WithMessage("Names cannot be empty.");

            RuleFor(f => f.URLs).Must((f, u) =>
            {
                for (int i = 0; i < u.Count; i++)
                {
                    if ((String.IsNullOrEmpty(u[i]) &&
                         !String.IsNullOrEmpty(f.Names[i])))
                        return false;
                }

                return true;
            })
            .WithMessage("URLs cannot be empty.");

Answer 2

Here is some Pseudo-code of a brute force solution. (I cannot think of any LINQ way of doing indexed comparisions) Sorry for the butchering of Fluent syntax.

Must(Names.Length == URLs.Length).WithMessage("Names must be equal in size to URLs");
for (int i = 0; i < Name.Length; i++)
{
    Must(string.IsNullOrEmpty(Names[i]) ^^ string.IsNullOrEmpty(URLs[i])).WithMessage("Either Name and URL must be non-empty, or both must be empty, index = " + i);
}

Hopefully you get the gist of it, you may also want to look into general LINQ methods, there is likely one that I missed. Basically you are wanting to do a join, and then check for invalid results in the merged list, but again I am unsure how to do a row by row and not simply a many to many join.