Tag Archives: FluentValidation

FluentValidation AddToModelState

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HOORAY FOR THIS!

I was working on some admin functionality, and I added a validator to a model. The problem is the forms are contained within Telerik MVC Extensions tabs, so the validators for one tab are applied even if you are on a different tab. No dice! I really wanted to offer some nice error messages though, so I refused to quit! 🙂

I thought, “why can’t I just new up my validator manually”. I did this, and at first I wasn’t seeing what I needed. I eventually found that I had to get the result of validator.Validate(model) and then check result.IsValid. I was originally assuming I’d just be checking validator.IsValid. Anyway, here is what I had to that point:

var validator = 
    new Nop.Admin.Validators.Catalog
        .AddProductRelationshipAttributeValidator(_localizationService);
var result = validator.Validate(model);
if (result.IsValid == false) {
    // Do some error stuff here
}

The only thing now was how to get the result errors into the model state? I found a great thread on the FluentValidation discussion board that was asking the same thing – do I have to iterate the errors and manually add them to the ModelState? It turns out the answer is “yes”, but there is the handy extension method mentioned in the subject! TADA! So now, I have this nice bit of code:

var validator = 
    new Nop.Admin.Validators.Catalog
        .AddProductRelationshipAttributeValidator(_localizationService);
var result = validator.Validate(model);
if (result.IsValid == false) {
    Response.StatusCode = 400;
    result.AddToModelState(ModelState, "");
    return ModelState.JsonValidation(JsonRequestBehavior.AllowGet);
}

The ModelState.JsonValidation bit is another extension method I have to put the ModelState into a standardized JSON result that I then pass through a couple of js functions. Those functions make sure the validation passes, and if the validation does not pass it puts the errors in the validation summary manually. It is all pretty handy stuff.

If anyone has any better ideas, I am all ears!

FluentValidation NotEqual client-side validation

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I wanted client-side validation for NotEqual. I started out writing my own and got 90% of the way there, then I got a little stuck. A quick Google revealed an existing Gist – however, the original implementation was only for NotEqual property comparison and I need a value compariosn. So, I forked it and made it work for my needs.

(function ($) {
    $.validator.addMethod("notequal", function (value, element, param) {
        if (param.indexOf("#") == -1) return value != param;
        return value != $(param).val();
    }, $.validator.messages.notequal);

    $.validator.unobtrusive.adapters.add("notequal", ["field"], 
    function (options) {
        options.rules["notequal"] = options.params.field;
        if (options.message) options.messages["notequal"] = options.message;
    });
})(jQuery);

FluentValidationModelValidatorProvider.Configure(provider =>
{
    provider.Add(typeof(NotEqualValidator), 
        (metadata, context, description, validator) => 
        new NotEqualClientRule(metadata, context, description, validator));
});

@model Test.Models.PersonModel
@using (Html.BeginForm())
{
    @Html.TextBoxFor(x => x.First)
    @Html.ValidationMessageFor(x => x.First)
    @Html.TextBoxFor(x => x.Last)
    @Html.ValidationMessageFor(x => x.Last)
    <button type="submit">OK</button>
}

[Validator(typeof(PersonValidator))]
public class PersonModel
{
    public string First { get; set; }
    public string Last { get; set; }
}
public class PersonValidator : AbstractValidator<PersonModel>
{
    public PersonValidator()
    {
        RuleFor(x => x.First).NotEqual(x => x.Last);
    }
}

Gist

When I look back at it, the whole hash check bit in the js just feels icky, so I think I’d go back and fix it up – probably just check to see if the jQuery selector exists, and if so compare .val() otherwise just compare the value. Whatever, it works for now even if it isn’t perfect…