I've tested MVC4 and it seems to now catch these validation errors automatically as expected. However I've had problems with fields such as
[Timestamp]
public byte[] Timestamp {get;set;}
no matter what I do these won't save and contain errors so I'll have to experiment a little more with those. Even using [ReadOnly(true)] is ignored and errors are still generated.
////// Author: Adam Tuliper /// adam.tuliper@gmail.com /// completedevelopment.blogspot.com /// www.secure-coding.com /// Use freely, just please retain original credit. /// /// This filter will add errors to ModelState when an entity fails validation and raises DbEntityValidationException /// The properties in the entity should share the same name as the ViewModel properties otherwise /// the errors will show up in the validation summary as 'general' errors not assigned to a property /// Also note in MVC4 this IS NOT REQUIRED as this is finally handled by the framework then. /// public class MapEntityExceptionsToModelErrorsAttribute : FilterAttribute, IExceptionFilter { public MapEntityExceptionsToModelErrorsAttribute() { } public void OnException(ExceptionContext filterContext) { if (!filterContext.ExceptionHandled && filterContext.Exception is DbEntityValidationException) { var model = filterContext.Controller.ViewData.Model; foreach (var error in ((System.Data.Entity.Validation.DbEntityValidationException)filterContext.Exception).EntityValidationErrors.First().ValidationErrors) { //If the error does not exist in the modelstate, then we will simply add it as a general validation message. var keys = filterContext.Controller.ViewData.ModelState.Keys; if (filterContext.Controller.ViewData.ModelState[error.PropertyName].Errors.Count == 0) { filterContext.Controller.ViewData.ModelState.AddModelError(error.PropertyName, error.ErrorMessage); } else { //Ensure this same message doesn't already exist. If ModelState is detected to have failed, //for instance from a [Required] field, then we don't want to re-add the error. However if we have //a more serious validation error, possibly stemming from some other data validation maybe not related to //our viewmodel (invalid dat in db, or some other code error bypassing validations) //then we want to add the error. This can happen on Save() and not caught in modelstate. bool found = false; foreach (var errorItem in filterContext.Controller.ViewData.ModelState[error.PropertyName].Errors) { if (errorItem.ErrorMessage == error.ErrorMessage) { found = true; break; } } if (!found) { filterContext.Controller.ViewData.ModelState.AddModelError("", error.ErrorMessage); } } } //No need to have other exception filters run filterContext.ExceptionHandled = true; filterContext.Result = new ViewResult() { ViewData = filterContext.Controller.ViewData }; } } }
