ASP.NET MVC 2.0 Validation and ErrorMessages
- by Raj Aththanayake
I need to set the ErrorMessage property of the DataAnnotation's validation attribute in MVC 2.0. For example I should be able to pass an ID instead of the actual error message for the Model property, for example...
[StringLength(2, ErrorMessage = "EmailContentID")]
[DataType(DataType.EmailAddress)]
public string Email { get; set; }
Then use this ID ("EmailContentID") to retrieve some content(error message) from a another service e.g database. Then the error error message is displayed to the user instead of the ID. In order to do this I need to set the DataAnnotation validation attribute’s ErrorMessage property.
It seems like a stright forward task by just overriding the DataAnnotationsModelValidatorProvider‘s protected override IEnumerable GetValidators(ModelMetadata metadata, ControllerContext context, IEnumerable attributes)
However it is complicated now....
A. MVC DatannotationsModelValidator’s ErrorMessage property is readonly. So I cannot set anything here
B. System.ComponentModel.DataAnnotationErrorMessage property(get and set) which is already set in MVC DatannotationsModelValidator so I cannot set it again. If I try to set it I get “The property cannot set more than once…” error message.
public class CustomDataAnnotationProvider : DataAnnotationsModelValidatorProvider
{
protected override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context, IEnumerable<Attribute> attributes)
{
IEnumerable<ModelValidator> validators = base.GetValidators(metadata, context, attributes);
foreach (ValidationAttribute validator in validators.OfType<ValidationAttribute>())
{
messageId = validator.ErrorMessage;
validator.ErrorMessage = "Error string from DB And" + messageId ;
}
//......
}
}
Can anyone please give me the right direction on this?
Thanks in advance.
