Test: Validations in ASP.NET MVC

Model Base validations:

ASP.NET MVC uses DataAnnotations attributes to implement validations. We can apply to the properties of model class.

Validation we can perform in model class by using namespace called as System.ComponentModel.DataAnnotations.

Required means value of the property must be provided

[Required(ErrorMessage ="Please Enter Employee Name")]

public string EmpName { get; set; }

Display: This attribute is used to display the property name.

[Display(Name ="Employee Name")]

public string EmpName { get; set; }

Compare: its means compare between password and conformPassword properties.

public string Password { get; set; }

[Compare("Password")]

public string ConformPassword { get; set; }

DataType: This attribute specifies the type of the property like Email

[DataType(DataType.EmailAddress,ErrorMessage ="InValid Email Address")]

public string EmailId { get; set; }

Range: this validation we can use for specifies the min to max value for property.

[Range(18,40,ErrorMessage ="Age should be between 18-40")]

public int Age { get; set; }

StringLength: this validation we can use how many numbers of characters are allowed for that particular property.

[StringLength(10,ErrorMessage ="Address should be 10 char long")]

public string Address { get; set; }

Remote Attribute:

It is an attribute for validation in Data Annotation, which is used in model class validate the record instantly.

It is used to call sum ajax calls. If validation is true then display and if validation is false it’s display error message.

First parameter Second parameter Third parameter

[Remote("IsUserNameValid","EmployeeModel", ErrorMessage = "Employee Name Already Exists.")]

public string EmpName { get; set; }

First parameter is Action name.

Second parameter is a Controller name

Third parameter is Error message

In above Remote attribute validation line like below

IsUserNameValid:

This is the JsonResult method which checks the details from database and returns true or false.

EmployeeModel:

This is MVC Controller name and inside that, IsUserNameValid JsonResult method is defined to check the details from database.

ErrorMessage :

This is used to show the error message.

Right click on model folder -> Add -> Class -> name(EmployeeModel.cs) -> Add

using System;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

using System.Linq;

using System.Web;

namespace WebApplication.Models

{

public class EmployeeModel

{

[Key]

public int EmpId { get; set; }

[Required(ErrorMessage ="Please Enter Employee Name")]

[Display(Name ="Employee Name")]

[Remote("IsUserNameValid","EmployeeModel", ErrorMessage = "Employee Name Already Exists.")]

public string EmpName { get; set; }

[Required(ErrorMessage = "Please Enter Password")]

public string Password { get; set; }

[Compare("Password")]

public string ConformPassword { get; set; }

[DataType(DataType.EmailAddress,ErrorMessage ="InValid Email Address")]

public string EmailId { get; set; }

[Range(18,40,ErrorMessage ="Age should be between 18-40")]

public int Age { get; set; }

[StringLength(10,ErrorMessage ="Address should be 10 char long")]

public string Address { get; set; }

}

when you apply validation in model it will display in View page.

Right click on controller-> Add -> Controller -> Name (EmployeeController.cs) page -> Add

public ActionResult Validations()

{

return View();

        }

public JsonResult IsUserNameValid(string EmpName)
        {
            if(EmpName == "supriya")
            {
                return Json(false, JsonRequestBehavior.AllowGet);
            }
            else
            {
                return Json(true, JsonRequestBehavior.AllowGet);
            }
        }

Right click on Validations method in Controller -> Add View

Select like above and click Add button. Its created Validations.cshtml page like below

@model WebApplication.Models.EmployeeModel

ViewBag.Title = "Validations";

}

<h2>Validations</h2>

@using (Html.BeginForm())

{

@Html.AntiForgeryToken()

<h4>EmployeeModel</h4>

<hr />

@Html.ValidationSummary(true, "", new { @class = "text-danger" })

@Html.LabelFor(model => model.EmpName, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.EmpName, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.EmpName, "", new { @class = "text-danger" })

</div>

@Html.LabelFor(model => model.Password, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.Password, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.Password, "", new { @class = "text-danger" })

</div>

@Html.LabelFor(model => model.ConformPassword, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.ConformPassword, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.ConformPassword, "", new { @class = "text-danger" })

</div>

@Html.LabelFor(model => model.EmailId, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.EmailId, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.EmailId, "", new { @class = "text-danger" })

</div>

@Html.LabelFor(model => model.Age, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.Age, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.Age, "", new { @class = "text-danger" })

</div>

@Html.LabelFor(model => model.Address, htmlAttributes: new { @class = "control-label col-md-2" })

@Html.EditorFor(model => model.Address, new { htmlAttributes = new { @class = "form-control" } })

@Html.ValidationMessageFor(model => model.Address, "", new { @class = "text-danger" })

</div>

</div>

}

<div>

@Html.ActionLink("Back to List", "Index")

</div>

@section Scripts {

@Scripts.Render("~/bundles/jqueryval")

}

when you build the application the output shown like below

Incase the validationsummary its give false, it's shows all required validation in above the fields like below
@Html.ValidationSummary(false, "", new { @class = "text-danger" }

AntiForgeryToken: it’s created a hidden key for form, that is valid till the form is submitted. Very time its create new key for form.

EditorFor: it is Html helper class to create a control base of the particular model

ValidationSummary to display all the error messages in the view.

ValidationMessageFor helper method to display field level error messages in the view.

Scaffolding Column:

It is used to hide property in UI, if it is EditorForModel and DisplayForModel.

First, we create method in HomeController.cs page like below:

public ActionResult Disply()

{

return View();

}

Add view for display method and copy below code

@model WebApplication.Models.EmployeeModel

ViewBag.Title = "Disply";

}

<h2>Disply</h2>

@using (Html.BeginForm())

{

@Html.AntiForgeryToken()

}

<div>

@Html.ActionLink("Back to List", "Index")

</div>

When you run the application, it shows output like below:

Add below code in beginform method in display view

@using (Html.BeginForm())

{

@Html.AntiForgeryToken()

@Html.EditorForModel("EmployeeModel")

}

In above screen I don’t want to display EmpId so, we go and change in EmployeeModel.cs page

In EmployeeModel.cs page I don’t want to delete EmpId but, I want to hide things in model class.

[ScaffoldColumn(false)]

public int EmpId { get; set; }

Test

Monday, November 18, 2019

Validations in ASP.NET MVC

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