Mvc3 self validating models
Then just open(or create) Home file and add the following code, Email, URL, Credit Card and File Extension input validations are very common. So create a new class file User inside Model folder and add the following code, Inside User Information class, I am using Email, Url, Credit Card and File Extensions validation attributes which are defined in Microsoft. You can override this by using Extensions property of File Extensions Attribute class. These kinds of errors are handled by the model-binding system before validation even happens.In MVC 1.0, these two situations were represented by the messages "The value 'dog' is not valid." and "A value is required." In the early MVC 2 previews, we added a pluggable validation system, and in-box we provide support for the validation attributes in System. Data Annotations (as well as backward compatibility with IData Error Info, though we suggest people migrate away from that at their convenience).It's null because we didn't bind any values into Home Address, and therefore never manufactured a new Home Address object.Let's expand our view to include just the street of the address: Now we'll get errors about missing values for City, State, and Zip, because this time we've bound at least one value inside of Home Address (namely, Street).
If the Home Address property had a [Required] attribute on it, it would fail, because Home Address would be null.
There are no validation errors for Last Name, because it wasn't part of the form. In an Input Validation system, the purpose of [Required] is to ensure that if the user was offered an opportunity to provide a value for the field, we'll make sure it isn't empty. Earlier today, we committed a change to MVC 2 that converted the validation system from Input Validation to Model Validation.
But what if the user wasn't offered the chance to edit that field? More importantly, what if a bad guy decided to try to "under-post" your form by leaving off the Last Name field? What this means is that we will always run all validators on an object, if that object had at least one value bound into it during model binding.
Given this new behavior, can we consider the [Required] attribute a security feature now? Even with Model Validation instead of Input Validation, we still have the same potentially unaddressed security issues that we've always had: "under-posting" and "over-posting".
Switching to Model Validation might make it easier to address "under-posting" in certain scenarios, but we're by no means completely safe yet.