Conditional validation on model in MVC

Question

I have a view & model that I use for both the edit and the insert page for a record. One of the business requirements is that a certain field is required on edit but not

Answer 1

You could use the RequiredIf validation attribute from the MVC Foolproof Validation project. I've used it on projects to enable just the functionality you require.

An alternative would be to use the RemoteAttribute and implement the logic yourself in a method.