I have a read only property on my 'Address' model 'CityStateZip'.
It's just a convenient way to get city, state, zip from a US address. It throws an exception if the country is not USA (the caller is supposed to check first).
public string CityStateZip
{
get
{
if (IsUSA == false)
{
throw new ApplicationException("CityStateZip not valid for international addresses!");
}
return (City + ", " + StateCd + " " + ZipOrPostal).Trim().Trim(new char[] {','});
}
}
This is part of my model so it gets bound. Prior to ASP.NET MVC2 RC2 this field never caused a problem during databinding. I never even really thought about it - after all it is only read only.
Now though with the January 2010 RC2 release it gives me an error during databinding - becasue the default model binder seems to want to check this value (even though it is read only).
It is the 'base.OnModelUpdated' line that causes this error to be triggered.
public class AddressModelBinder : DefaultModelBinder
{
protected override void OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
base.OnModelUpdated(controllerContext, bindingContext);
Last minutes changes to the modelbinder evidently caused this change in behavior - but I'm not quite sure yet what the repurcussions of it are - or whether or not this is a bug? I'm passing this on to the MVC team but curious if anyone else has any suggestions in the meantime how I can prevent this property from binding.
This article is well worth reading about the changes - but doesn't mention readonly properties at all (not that I would expect it to). The issue (if there is one) may be broader than this situation - I'm just not sure about any repurcussions - if any!
Input Validation vs. Model Validation in ASP.NET MVC
As requested by @haacked here's the stacktrace :
I get this by simply adding the following line to ANY model and making a post to the corresponding action method. In this instance I added it to my simplest possible model.
public string Foo { get { throw new Exception("bar"); } }
[TargetInvocationException: Property accessor 'Foo' on object 'Rolling_Razor_MVC.Models.ContactUsModel' threw the following exception:'bar']
System.ComponentModel.ReflectPropertyDescriptor.GetValue(Object component) +390
System.Web.Mvc.<>c_DisplayClassb.<GetPropertyValueAccessor>b_a() +18
System.Web.Mvc.ModelMetadata.get_Model() +22
System.Web.Mvc.ModelMetadata.get_RealModelType() +29
System.Web.Mvc.<GetValidatorsImpl>d_0.MoveNext() +38
System.Linq.<SelectManyIterator>d_142.MoveNext() +273
System.Web.Mvc.<Validate>d__5.MoveNext() +644
System.Web.Mvc.DefaultModelBinder.OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext) +92
System.Web.Mvc.DefaultModelBinder.BindComplexElementalModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Object model) +60
System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +1048
System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +280
System.Web.Mvc.Controller.TryUpdateModel(TModel model, String prefix, String[] includeProperties, String[] excludeProperties, IValueProvider valueProvider) +449
System.Web.Mvc.Controller.TryUpdateModel(TModel model) +73
Rolling_Razor_MVC.Controllers.CompanyController.ContactUsForm(FormCollection formData) in R:\WEBSITES\ROLLINGRAZOR.COM - MVC\Rolling Razor MVC\Controllers\CompanyController.cs:158
lambda_method(ExecutionScope , ControllerBase , Object[] ) +86
System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary2 parameters) +178
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 parameters) +24
System.Web.Mvc.<>c__DisplayClassd.<InvokeActionMethodWithFilters>b__a() +52
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func1 continuation) +254
System.Web.Mvc.<>c_DisplayClassf.<InvokeActionMethodWithFilters>b_c() +19
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func1 continuation) +254
System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func1 continuation) +254
System.Web.Mvc.<>c_DisplayClassf.<InvokeActionMethodWithFilters>b_c() +19
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList1 filters, ActionDescriptor actionDescriptor, IDictionary2 parameters) +192
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +314
System.Web.Mvc.Controller.ExecuteCore() +105
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +39
System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +7
System.Web.Mvc.<>c_DisplayClass8.<BeginProcessRequest>b_4() +34
System.Web.Mvc.Async.<>c_DisplayClass1.<MakeVoidDelegate>b_0() +21
System.Web.Mvc.Async.<>c__DisplayClass81.<BeginSynchronous>b__7(IAsyncResult _) +12
System.Web.Mvc.Async.WrappedAsyncResult1.End() +59
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +7
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8679134
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155