验证整个类MVC3 C＃

Question

Currently i have a customer class that the user can partially create, and finish the detailed information down the line. For example it looks like this

New Customer

    [Required(ErrorMessage = "Business name is required.")]
    [Display(Name = "Business Name:")]
    public string BusinessName { get; set; }

    [Display(Name = "Address:")]
    public string Address { get; set; }

    [Display(Name = "City:")]
    public string City { get; set; }

    [Display(Name = "State:")]
    public string State { get; set; }

    [Display(Name = "Zip:")]
    public string Zip { get; set; }

Customer Checkout

    [Required(ErrorMessage = "Business name is required.")]
    [Display(Name = "Business Name:")]
    public string BusinessName { get; set; }

    [Required(ErrorMessage = "Address is required.")]
    [Display(Name = "Address:")]
    public string Address { get; set; }

    [Required(ErrorMessage = "City is required.")]
    [Display(Name = "City:")]
    public string City { get; set; }

    [Required(ErrorMessage = "State is required.")]
    [Display(Name = "State:")]
    public string State { get; set; }

    [Required(ErrorMessage = "Zip is required.")]
    [Display(Name = "Zip:")]
    public string Zip { get; set; }

when the user goes to checkout i need to make sure that they do finish filling out the information if some is missing. My thought process was to create a Customer Checkout class populated with the information from when they created a new customer and check to see if its valid before passing them along to checkout. My issue is the only way i know to do that is to check each field against string.isNullOrEmpty() but i know there has to be a better way. I will have to check 25 fields like this. I know that you can check if a Model is valid, but i need to do this at a class level in my Data Access Layer checking to make sure all[required] fields have data. Hopefully i am just overlooking something

almost like I need some way to do something like

bool hasErrors = false 

foreach attribute in my class 
if it is marked as [required]
check to make sure not null or empty
if it is set hasErrors = true

thanks!

Answer 1

You need to create a custom validation for your model,

Implements the interface IValidatableObject and override the implement the method Validate and create your custom validation for example

public class Foo : IValidatableObject
{

      public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
      {
          //make your custom rules for validation on server side
        if ((fooAttribute== true) && (fooAtribute2 == String.Empty))
        {
            yield return new ValidationResult("Your custom Error");
        }
      }

} 

NOTE: With this you're achieving validation on the server side of your application

Answer 2

If performance is not a consideration you can use reflection to automatically validate your object.

static class ObjectValidator
{
    public static bool IsValid(object toValidate)
    {
        Type type = toValidate.GetType();
        var properties = type.GetProperties();
        foreach(var propInfo in properties)
        {
            var required = propInfo.GetCustomAttributes(typeof(RequiredAttribute), false);
            if (required.Length > 0)
            {
                var value = propInfo.GetValue(toValidate, null);
                // Here you'll need to expand the tests if you want for types like string
                if (value == default(propInfo.PropertyType))
                    return false;
            }
        }
        return true;
    }
}