MVC3 Model Validation (Compare propery in another class) - asp.net-mvc-3

Question

public class User
{
string username;
string password;
}
public class registration
{
User user;
**[compare(user.password)]**
string newPass;
}
It produces error (Property is not found)
Is there a way to create validation for a property inside another class ?
thanks

Answer 1

public class CompareOther:ValidationAttribute, IClientValidatable
{
private readonly string testedPropertyName;
private readonly string className;
public CompareOther(string testedPropertyName)
{
string[] word = testedPropertyName.Split('.');
this.testedPropertyName = word[1];
this.className = word[0];
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var propertyTestedInfo = validationContext.ObjectType.GetProperty(this.className);
if (propertyTestedInfo == null)
{
//return new ValidationResult("unknown property");
return new ValidationResult(string.Format("unknown property {0}.{1}",this.className ,this.testedPropertyName));
}
var propertyObject = propertyTestedInfo.GetValue(validationContext.ObjectInstance,null);
var propertyTestedValue = getValue(testedPropertyName,propertyObject);
if (value == null)
{
return ValidationResult.Success;
}
if (propertyTestedValue == null)
{
return ValidationResult.Success;
}
if (propertyTestedValue.ToString() == value.ToString())
{
return ValidationResult.Success;
}
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ErrorMessage = this.ErrorMessageString,
ValidationType = "lessthan"
};
rule.ValidationParameters["propertytested"] = this.testedPropertyName;
yield return rule;
}
private Object getValue(string name,Object obj)
{
if (obj == null)
return null;
Type type = obj.GetType();
PropertyInfo info = type.GetProperty(name);
if (info == null)
{ return null; }
obj = info.GetValue(obj, null);
return obj;
}
}