ASP.NET MVC Model Validation using Data Annotations

In ASP.NET MVC, there are several ways to validate the model data prior to saving the data into the data store.

Validate the model data explicitly
Implement the IValidateableObject interface
Specify Data Annotations [Recommended]

Data Annotation is recommended because there are built-in Data Annotations in .NET Framework. You don’t have to implement your own validation logic, instead specifying the Validation Data Annotation that you need. The Data Annotations specified support both server-side & client-side validation. In case the built-in cannot fulfill your requirements, you can also implement your own Data Annotation.

Built-in Data Annotations

Namespace: System.ComponentModel.DataAnnotations

Validation Attribute	Description
CompareAttribute	Compares two properties
CustomValidationAttribute	Specifies a custom validation method
DataTypeAttribute	Data type of the data field
MaxLengthAttribute	Max. length of array or string data allowed
MinLengthAttribute	Min. length of array or string data allowed
RangeAttribute	Numeric range constraints for the data field value
RegularExpressionAttribute	Data field value must match the specified regular expression
RequiredAttribute	Data field value is required
StringLengthAttribute	Min. and max. length of characters that are allowed in a data field

Namespace: System.Web.Security

Validation Attribute	Description
MembershipPasswordAttribute	Validates whether a password field meets the current password requirements for the membership provider

Code Sample

using System;
using System.ComponentModel.DataAnnotations;
using System.Web.Security;
 
namespace AspNetMvc.Models
{
    public class User
    {
        [DataType(DataType.Text)]
        [StringLength(30, MinimumLength = 6)]
        [Required()]
        public string UserName { get; set; }
 
        [DataType(DataType.Password)]
        [StringLength(255, MinimumLength = 8)]
        [Required()]
        [MembershipPassword()]
        public string Password { get; set; }
 
        [Compare("Password")]
        [DataType(DataType.Password)]
        [StringLength(255, MinimumLength = 8)]
        [Required()]
        [MembershipPassword()]
        public string ConfirmPassword { get; set; }
 
        [DataType(DataType.EmailAddress)]
        [StringLength(128)]
        [Required()]
        public string Email { get; set; }
 
        [DataType(DataType.PhoneNumber)]
        [RegularExpression("^[0-9]{8}$")]
        [StringLength(32)]
        public string Phone { get; set; }
 
        [DataType(DataType.Date)]
        public DateTime Birthday { get; set; }
 
        [DataType(DataType.MultilineText)]
        [StringLength(255)]
        public string Remarks { get; set; }
    }
}

Client-side Validation

Edit the ~\web.config file as the following

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <appSettings>
    <add key="webpages:Version" value="2.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="PreserveLoginUrl" value="true" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
</configuration>

Check the ~\App_Start\BundleConfig.cs file to include the following line

bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(
            "~/Scripts/jquery.validate.unobtrusive*",
            "~/Scripts/jquery.validate*"));

References

vinicius-stutz/readme.md

ASP.NET MVC Model Validation using Data Annotations