fluent validation collection items not null/empty

c# asp.net-mvc fluentvalidation
raklos picture raklos · Apr 1, 2014 · Viewed 14.1k times · Source

Im using fluent validation with mvc4

In my Model I have a list:

public List<int> TransDrops { get; set; }

in the view im creating text boxes for each item in the list.

I want to subsequently make sure each field is filled in. (not null/empty)

OrderDetailsViewModelValidator is the validator on the model, what do i need?

Thanks

Answer

Evgeny Levin picture Evgeny Levin · Apr 6, 2015

First you have to use nullable integer type for collection item, otherwise empty textboxes would be bound to zero value, what makes impossible to distinguish empty textboxes and filled with zeros.

public List<int?> TransDrops { get; set; }

Next, use predicate validator (Must rule):

RuleFor(model => model.TransDrops)
    .Must(collection => collection == null || collection.All(item => item.HasValue))
    .WithMessage("Please fill all items");

If you need to prevent empty collection being successfully validated, just add NotEmpty() rule before predicate validator: it checks that any IEnumerable not null, and have at least 1 item.

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