maztt

Using Datannotion is great but there are scenarious in which the current attributes compare, range etc becomes inadequate especially for the comparisions. So we create here our own custom validation using ValidationAttribute class which is the base class for all the annotation attributes. So by deriving from it and overriding the Isvalid method we can create our custom attribute for the model. So here is the scenario in which I will be validating the Username against the password which should not be equal. Compare attribute cannot be used in this scenario so I have created a custom attribute for that. Here is the model with the attribute. User View Model [CompareUserPass("UserName", "Password", ErrorMessage = "UserName and password cannot be equal")] public class UserView { [Required(ErrorMessage = "UserName Required")] public string UserName { get; set; } [Required(...

One of the thing that makes asp.net.mvc so interesting is default model binding. Model binding in simple words allows you to take the posted form data from the view and bind it to the action method's parameter in the controller without any fuss. But there is a security flaw in model binding which everyone using asp.net mvc should know .The problem is, in asp.net mvc controller you cannot be sure what you got as the posted value from the view because it is absolutely possible that an extra property, or an overwritten property which you don't want get passed to the controller which could spell disaster. And in the controller if the property matches the orginal property then the things could get out of hand. Here's a simple scenario to understand more what I have defined. A person filling a create user form to become the member of the website requiring some payment in the process passed an Isenabled=true property (which we all have) and unfortunately there is a match in the mo...

Most of the time in the real world applications it is not possible to map the database model to your presentation view directly because of the fact you may need some additional fields in your view. Using view Data or Viewbag is not always the good idea as it may make things harder or less elegant which are much easier to do. We are creating the User create view as an example here in which confirm password field is additional field in the view and it has nothing to do with the database model. So in this case you would create one model for the database fields as usual and one extra model for the view. The problem is that in the controller you have to map each property from your model for the database to the model for the view manually which shouldn't be done because it is not a good practice as there is a tool for that. The third party tool the Automapper solves this problem by automatically mapping your view model which you get from the view in the controller to the database mod...