How to create custom attribute in mvc?

Custom attribute implements the ASP.NET MVC filters(filter interface) and can contain your piece of code or logic. You can make your own custom filters or attributes either by implementing ASP.NET MVC filter interface or by inheriting and overriding methods of ASP.NET MVC filter attribute class if available. Typically, Filters are used to perform the following common functionalities in your ASP.NET MVC application.: Custom Authentication; Custom Authorization(User based or Role based); Error handling or logging; User Activity Logging; Data Caching; Data Compression. Types of Filters The ASP.NET MVC framework provides five types of filters.: Authentication filters (New in ASP.NET MVC5); Authorization filters; Action filters; Result filters; Exception filters. read less

An attribute or custom attribute implements the ASP.NET MVC filters(filter interface) and can contain your piece of code or logic. You can make your own custom filters or attributes either by implementing ASP.NET MVC filter interface or by inheriting and overriding methods of ASP.NET MVC filter attribute class if available. Typically, Filters are used to perform the following common functionalities in your ASP.NET MVC application. Custom Authentication Custom Authorization(User based or Role based) Error handling or logging User Activity Logging Data Caching Data Compression read less

Create a class inheriting “ValidationAttribute” and implementing “IClientValidatable” interface. “IClientValidatable” interface implementations is required if you want to enable your validation at client side. Override “IsValid” method and add your custom validation logic there. Implement “GetClientValidationRules” method. You can add custom parameters in this method that you require on client side for validation. Create a JavaScript file and register your client methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod” methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod”. We will look into it in detail when I will give detailed explanation of the code attached in the coming section. read less

Following are the Steps for creating Custom Attributes Step 1 : Create a class inherit it from “ValidationAttribute” and implement “IClientValidatable” interface. namespace MvcCustomValidation.Validations { [AttributeUsage(AttributeTargets.Property, AllowMultiple = true, Inherited = false)] public class MyCustomValidation : ValidationAttribute, IClientValidatable { } } Step 2 : protected override ValidationResult IsValid (object value, ValidationContext validationContext) { //Your Logic Here } Step 3: Implement “GetClientValidationRules” method. public IEnumerable (Use HTML Angular opening bracket)ModelClientValidationRule(Use HTML Angular Closing bracket) GetClientValidationRules(ModelMetadata metadata, ControllerContext context) { // add custom parameters in this method that you require on client side for validation. } Step 4 : Create a JavaScript file and register your client methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod” methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod”. Hope you found it easy ... Thank You.. read less

Follow below steps: Create a class inheriting “ValidationAttribute” and implementing “IClientValidatable” interface. “IClientValidatable” interface implementations is required if you want to enable your validation at client side. Override “IsValid” method and add your custom validation logic there. Implement “GetClientValidationRules” method. You can add custom parameters in this method that you require on client side for validation. Create a JavaScript file and register your client methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod” methods here using “jQuery.validator.unobtrusive.add” and “jQuery.validator.addMethod”. We will look into it in detail when I will give detailed explanation of the code attached in the coming section. read less

You need to register an adapter for the new attribute in order to enable client side validation. Since the RegularExpressionAttribute already has an adapter, which is RegularExpressionAttributeAdapter, all you have to do is reuse it. Use a static constructor to keep all the necessary code within the same class. [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false)] public class EmailAddressAttribute : RegularExpressionAttribute { private const string pattern = @"^\w+([-+.]*[\w-]+)*@(\w+([-.]?\w+)){1,}\.\w{2,4}$"; static EmailAddressAttribute() { // necessary to enable client side validation DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(EmailAddressAttribute), typeof(RegularExpressionAttributeAdapter)); } public EmailAddressAttribute() : base(pattern) { } } read less