Annotation provides instant user input checking facility at client side and provides to asp developer, a wide range of validator attributes.Data Annotation makes the validating process easy and quick.Data Annotation attributes directly applies to Model class member and those members are bounded to accept valid user input according to Data Annotation Rule.Data Annotation can be used after adding following namespace.Thus, for the Date Time property if you create a partial in Views/[loc]/Editor Templates/(or cshtml for razor), that view will be used to render the property when using any of the Html. One thing that the Data Type() validation attribute does not do is any actual validation.To see this, let’s take a look at the Email Address property above.Introduction This article describes a simple approach to validating dates received as strings (e.g., 2/21/2008).It requires on a few lines of code but will confirm that the date provided as a string is an actual date.
For example, you want to create a custom attribute In this chapter, I explained how to use Data Annotation for validating input field in ASP. I also explained how to add custom validation rule in Data Annotation.In the next chapter, you will learn Remote Validation in ASP. Remote Validation checks user input field instantly when the focus jumps out from input control.By Rick Anderson, Dave Paquette, and Jerrie Pelser This document demonstrates working with Forms and the HTML elements commonly used on a Form.[Required(Error Message = "Email ID is Required")] [Data Type(Data Type.Email Address)] [Max Length(50)] [Regular Expression(@ "[a-z0-9._% -] @[a-z0-9.-] \.[a-z]", Error Message = "Incorrect Email Format")] public string Email Creation of form is same and nothing changed.The formats for the date string used in this example conform to the US standard of MM/DD/YYYY but that can easily be modified to work with other UI cultures.The method shown may be of use if you have an application that receives dates as strings rather than as actual Date Time values.We recommend you read Introduction to Tag Helpers before you read this document.In many cases, HTML Helpers provide an alternative approach to a specific Tag Helper, but it's important to recognize that Tag Helpers don't replace HTML Helpers and there's not a Tag Helper for each HTML Helper.Till now, you learned how to use predefined Data Annotation attribute to validate input field.But, what is the way of adding a custom rule in data annotation?