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Using Fluent Validation with ASP.NET MVC

By using FluentValidation Package you can apply validation easily, for unit test validation rule FluentValidation provide some easy way, FluentValidation split to validation from the basic model. If you want to inject Dependencies into your validation rule then you must use FluentValidation.

Library of FluentValidation uses Fluent interface and lambda expressions for building validation rules for your business objects.  For your validation object, FluentValidation is one way of setting, using fluent validation you can separate validation from business logic. Separating validation helps clean up your domain code and make it more cohesive, as well as giving you a single place to look for validation logic.

Before starting to apply Fluent Validation you have to add its library/dll, you can directly download it from http://fluentvalidation.codeplex.com/


Fluent Validation is also available as a Nuget package, so search FluentValidation.MVC4 and install from Nuget Package Manager. After installing, you can find two new assemblies added to your application named as Fluent Validation and Fluent Validation.Mvc.


Add a class FValidator and write all validation rules like below.

namespace WebApplication1.Models
{
    public class FValidator : AbstractValidator<RegistrationModels>
    {
        public FValidator()
        {
            RuleFor(x => x.uName).NotNull().WithMessage("please Enter the Name");
            RuleFor(x => x.uEmail).NotNull()
.WithMessage("please Enter the Email")
.EmailAddress().WithMessage("Please Enter valid Email");
            RuleFor(x => x.uMobileNo).NotNull()
.WithMessage("please Enter Mobile").Length(6,10);
            RuleFor(x => x.uCountry).NotNull()
.WithMessage("please Enter the Country");
        }
    }
}

Now link FValidator validation class to the RegistrationModels class by specifying it in the Validation attribute as below:

namespace WebApplication1.Models
{
    [FluentValidation.Attributes.Validator(typeof(FValidator))]
    public class RegistrationModels
    {
        [Display(Name = "Name")]
        public string uName { getset; }
        [Display(Name = "Email")]
        public string uEmail { getset; }
        [Display(Name = "Mob Number")]
        public string uMobileNo { getset; }
        [Display(Name = "Country")]
        public string uCountry { getset; }
    }
}

RegistrationController is below.

namespace WebApplication1.Controllers
{
    public class RegistrationController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }
        [HttpPost]
        public ActionResult Index(RegistrationModels mRegister)
        {
            if (ModelState.IsValid)
            {
                return View("Completed");
            }
            else
            {
                return View(mRegister);
            }

        }
    }
}

Your Registration.cshtml code looks like below.
@model WebApplication1.Models.RegistrationModels
@{
    ViewBag.Title = "Home Page";
}

@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)
    <fieldset>
        <legend>Form</legend>
        <div class="form-group">
            @Html.Label("Name"new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.uName, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.uName)
            </div>
        </div>
        <div class="form-group">
            @Html.Label("Email"new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.uEmail, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.uEmail)
            </div>
        </div>
        <div class="form-group">
            @Html.Label("Mobile"new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.uMobileNo, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.uMobileNo)
            </div>
        </div>
        <div class="form-group">
            @Html.Label("Mobile"new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.uCountry, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.uCountry)
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" class="btn btn-default" value="Submit" />
            </div>
        </div>
    </fieldset>
} 

Finally call the FluentValidationModelValidatorProvider.Configure() method inside your global.asax file as bellow.
namespace WebApplication1{    public class MvcApplication : System.Web.HttpApplication    {        protected void Application_Start()        {            AreaRegistration.RegisterAllAreas();            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);            RouteConfig.RegisterRoutes(RouteTable.Routes);            BundleConfig.RegisterBundles(BundleTable.Bundles);            FluentValidationModelValidatorProvider.Configure();        }    }}

The validation messages are shown below: