Check if Model is valid outside of Controller

Question

I have a helper class that is passed an array of values that is then passed to a new class from my Model. How do I verify that all the values given to this class are valid? In other words, how do I use the functionality of ModelState within a non-controller class.

From the controller:

public ActionResult PassData()
{
    Customer customer = new Customer();
    string[] data = Monkey.RetrieveData();
    bool isvalid = ModelHelper.CreateCustomer(data, out customer);
}

From the helper:

public bool CreateCustomer(string[] data)
{
    Customter outCustomer = new Customer();
    //put the data in the outCustomer var
    //??? Check that it's valid

}

Solution

You could use the data annotations validation outside of an ASP.NET context:

public bool CreateCustomer(string[] data, out Customer customer)
{
    customer = new Customer();
    // put the data in the customer var

    var context = new ValidationContext(customer, serviceProvider: null, items: null);
    var results = new List<ValidationResult>();

    return Validator.TryValidateObject(customer, context, results, true);
}

Comments

[neumann1990]

Unfortunately, this validation doesn't recurse through any complex child objects or collections. The Validator.TryValidateObject(...) just does immediate property and field validations, and calls it a day, as opposed the the validation that happens on model binding in the Controller in MVC world which traverse the entire object graph.