In my Silverlight RIA app I can successfully inject an ExceptionHelper class via constructor injection:
[InjectionConstructor]
public CDashCatDataService(IExceptionHelper exceptionHelper)
{
_exceptionHelper = exceptionHelper;
SetUp();
}
void SetUp()
{
if (_context == null)
{
try
{
throw new Exception("this is a test exception");
_context = new CDASHDomainContext();
}
catch (Exception ex)
{
_exceptionHelper.HandleException(ex, string.Format("{0} -> {1}", GetType().FullName, "Setup"));
}
}
Context = _context;
}
The SetUp method successfully logs and handles the test exception.
However, I can't get this working if I use property injection instead:
[Dependency]
public IExceptionHelper ExceptionHelper { get; set; }
and then using
catch (Exception ex)
{
ExceptionHelper.HandleException(ex, string.Format("{0} -> {1}", GetType().FullName, "Setup"));
}
in the SetUp method. If I use this, the test exception is not logged and handled.
I'm clearly missing something here - any ideas?
I think this is because the ExceptionHelper property is being called from the constructor via the SetUp method and you can't call injected properties until after the constructor has executed.
Related
I'm quite new to unit tests and I've got some troubles testing this command
internal async Task OnDeleteTreasurerCommandExecute(TesorieraItemResult tesoriera)
{
try
{
if (await MessageService.ShowAsync("Confermare l'operazione?", string.Empty, MessageButton.YesNo, MessageImage.Question) == MessageResult.Yes)
{
await repository.DeleteTesorieraItemAsync(tesoriera.ID_ISTITUTO,tesoriera.ID_DIVISA,tesoriera.PROGRESSIVO);
await MessageService.ShowInformationAsync("Operazione completata");
if (SelectedInstitute != null)
await OnLoadDataCommandExecute();
}
}
catch (Exception ex)
{
ErrorService.HandleError(GetType(), ex);
}
}
I'm using Catel as MVVM framework
how do I simulate the yes/no answers?
Thanks
You need to substitute the MessageService with a class that can return yes or no answer. Here's an example using NSubstitute.
Install-Package NSubstitute
Install-Package NUnit
Let us say you have a class that has a method that
needs Yes, then No:
public class AccountViewModel
{
readonly IMessageService _messageService;
readonly ICustomerRepository _customerRepository;
public AccountViewModel(IMessageService messageService, ICustomerRepository customerRepository)
{
_messageService = messageService;
_customerRepository = customerRepository;
}
public async Task OnDeleteCustomer(Customer customer)
{
if (await MessageService.ShowAsync(
"Confirm?",
string.Empty,
MessageButton.YesNo,
MessageImage.Question) == MessageResult.Yes)
{
_customerRepository.Delete(customer);
await MessageService.ShowInformationAsync("Completed");
}
}
}
Then your test case looks like this:
public class TestAccountViewModel
{
[TestCase]
public class TestDeleteCustomer()
{
// arrange
var messageService = Substitute.For<IMessageService>();
messageService
.ShowAsync(
Arg.Any<string>(),
Arg.Any<string>(),
Arg.Any<MessageButton>(),
Arg.Any<MessageImage>())
.Returns(Task.FromResult(MessageResult.Yes);
messageService
.ShowInformationAsync(Arg.Any<string>())
.Returns(Task.FromResult<object>(null));
var customerRepository = Substitute.For<ICustomerRepository>();
// act
var sut = new AccountViewModel(messageService, customerRepository);
var customer = new Customer();
sut.OnDeleteCustomer(customer);
// assert
Assert.IsTrue(customerRepository.Received().DeleteCustomer(customer));
}
}
In a past version, Catel provided a test implementation of the IMessageService that allowed you to queue expected results so you could test the different paths inside a command.
I just noticed this class is no longer available, but you can easily implement a test stub yourself (using mocking, etc). Or you could contribute to Catel and revive the test implementation.
I have a model implementing both INotifyPropertyChanged and INotifyDataErrorInfo. The Property changed event fires when ever I have a property modified, but for some reason when I raise the Error event handler, the UI does ever invoke the GetErrors method. This results in the validation error not being rendered to the UI.
Can someone take a look at how I have the INotifyDataErrorInfo set up and tell me if I'm doing something wrong?
Base model implementation
public class BaseChangeNotify : INotifyPropertyChanged, INotifyDataErrorInfo
{
private bool isDirty;
private Dictionary<string, List<string>> errors = new Dictionary<string, List<string>>();
public BaseChangeNotify()
{
}
public event PropertyChangedEventHandler PropertyChanged;
public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
public bool IsDirty
{
get
{
return this.isDirty;
}
set
{
this.isDirty = value;
this.OnPropertyChanged();
}
}
public bool HasErrors
{
get
{
return this.errors.Count(e => e.GetType() == typeof(ErrorMessage)) > 0;
}
}
public IEnumerable GetErrors(string propertyName)
{
if (string.IsNullOrEmpty(propertyName) ||
!this.errors.ContainsKey(propertyName))
{
return null;
}
return this.errors[propertyName];/*.Where(e => (e is ErrorMessage));*/
}
protected virtual void AddError(string propertyName, string error, bool isWarning = false)
{
if (!this.errors.ContainsKey(propertyName))
{
this.errors[propertyName] = new List<string>();
}
if (!this.errors[propertyName].Contains(error))
{
if (isWarning)
{
this.errors[propertyName].Add(error);
}
else
{
this.errors[propertyName].Insert(0, error);
}
this.OnErrorsChanged(propertyName);
}
}
protected virtual void RemoveError(string propertyName, string error)
{
if (this.errors.ContainsKey(propertyName) &&
this.errors[propertyName].Contains(error))
{
this.errors[propertyName].Remove(error);
if (this.errors[propertyName].Count == 0)
{
this.errors.Remove(propertyName);
}
this.OnErrorsChanged(propertyName);
}
}
public virtual void OnPropertyChanged([CallerMemberName] string propertyName = "")
{
// Perform the IsDirty check so we don't get stuck in a infinite loop.
if (propertyName != "IsDirty")
{
this.IsDirty = true; // Each time a property value is changed, we set the dirty bool.
}
if (this.PropertyChanged != null)
{
// Invoke the event handlers attached by other objects.
try
{
// When unit testing, this will always be null.
if (Application.Current != null)
{
try
{
Application.Current.Dispatcher.Invoke(() =>
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)));
}
catch (Exception)
{
throw;
}
}
else
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
catch (Exception)
{
throw;
}
}
}
/// <summary>
/// Called when an error has changed for this instance.
/// </summary>
/// <param name="propertyName">Name of the property.</param>
public virtual void OnErrorsChanged([CallerMemberName] string propertyName = "")
{
if (string.IsNullOrWhiteSpace(propertyName))
{
return;
}
if (this.ErrorsChanged != null)
{
this.ErrorsChanged(this, new DataErrorsChangedEventArgs(propertyName));
}
}
}
Model using the implementation
public class PayItem : BaseChangeNotify
{
private Section section;
public Section Section
{
get
{
return this.section;
}
set
{
this.section = value;
this.ValidateSection();
this.OnPropertyChanged();
}
}
private void ValidateSection([CallerMemberName] string propertyName = "")
{
const string sectionError = "You must select a Section.";
if (this.Section == null || this.Section.Name.Length > 1)
{
this.AddError(propertyName, sectionError);
}
else
{
this.RemoveError(propertyName, sectionError);
}
}
The View trying to use it
<ComboBox Name="SectionComboBox"
ItemsSource="{Binding Path=ProjectSections}"
SelectedItem="{Binding Path=SelectedPayItem.Section,
NotifyOnValidationError=True,
UpdateSourceTrigger=PropertyChanged}">
The app is being wrote in WPF, and the WPF docs are pretty scarce. I've read through the Silverlight documentation on it along with a few other blog posts I found on the internet and have implemented in each of the different ways the blog authors suggest. Each time the result is the same, the GetErrors() method never gets hit by the Binding engine.
Can anyone see something that I'm doing wrong? When my model has its property set, I can step through the debugger and ultimately end up within the OnErrorsChanged event handler, and the event gets invoked. Nothing happens when it gets invoked though, so I'm stumped.
Thanks in advance for any help.
Johnathon
EDIT
Also I would like to note that I had been using IDataErrorInfo in the base class for the last couple of months without any issues. The binding worked, the errors were reported to the View and everything was happy. When I changed from IDataErrorInfo to INotifyDataErrorInfo, the validation appeared to stop communicating with the View.
The INotifyDataErrorInfo.HasErrors property must return true when raising the ErrorsChanged event. Otherwise the binding engine ignores the errors. Your HasErrors property will return false all the time. This happens because you are checking for items of type ErrorMessage but your dictionary contains items of type KeyValuePair<string, List<string>>. Besides that it is highly inefficent to count all the items. You should use .Any() instead.
By the way, the MSDN documentation of INotifyDataErrorInfo says the following:
Note that the binding engine never uses the HasErrors property,
although you can use it in custom error reporting.
This is plain wrong and it took me hours to find that out.
I am trying to call a WCF service from a Silverlight client using channel factory as per this link. Working with channel factory is something new for me so please bear with me!
Everything mentioned in the article works just fine. But now I am trying to implement Fault exceptions so that I can catch the actual exceptions on the Silverlight side. But for some reason I always end up catching CommunicationException which doesn't serve my purpose.
Here is my service contract:
[OperationContract]
[FaultContract(typeof(Fault))]
IList<Category> GetCategories();
Catch block of the service:
catch (Exception ex)
{
Fault fault = new Fault(ex.Message);
throw new FaultException<Fault>(fault, "Error occured in the GetCategories service");
}
Service contract for client with async pattern:
[OperationContract(AsyncPattern = true)]
[FaultContract(typeof(Fault))]
IAsyncResult BeginGetCategories(AsyncCallback callback, object state);
IList<Category> EndGetCategories(IAsyncResult result);
Here is the service call from client:
ICommonServices channel = ChannelProviderFactory.CreateFactory<ICommonServices>(COMMONSERVICE_URL, false);
var result = channel.BeginGetCategories(
(asyncResult) =>
{
try
{
var returnval = channel.EndGetCategories(asyncResult);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
CategoryCollection = new ObservableCollection<Category>(returnval);
});
}
catch (FaultException<Fault> serviceFault)
{
MessageBox.Show(serviceFault.Message);
}
catch (CommunicationException cex)
{
MessageBox.Show("Unknown Communications exception occured.");
}
}, null
);
I am sharing the DataContract .dll between both the service and client applications and hence they are referring to same data contract classes (Category & Fault)
Please tell me what I am doing wrongly?
UPDATE: I do clearly see the fault exception sent from the service in Fiddler. Which makes me believe I am missing something in the client side.
For catching normal exceptions in sivleright you must create "Silverlight-enabled WCF Service" (Add -> New Item -> Silverlight-enabled WCF Service).
If you already created standard WCF service you can add attribute [SilverlightFaultBehavior] to your service manually.
Default implementation of this attribute is:
public class SilverlightFaultBehavior : Attribute, IServiceBehavior
{
private class SilverlightFaultEndpointBehavior : IEndpointBehavior
{
public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
{
}
public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
{
}
public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
{
endpointDispatcher.DispatchRuntime.MessageInspectors.Add(new SilverlightFaultMessageInspector());
}
public void Validate(ServiceEndpoint endpoint)
{
}
private class SilverlightFaultMessageInspector : IDispatchMessageInspector
{
public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
{
return null;
}
public void BeforeSendReply(ref Message reply, object correlationState)
{
if ((reply != null) && reply.IsFault)
{
HttpResponseMessageProperty property = new HttpResponseMessageProperty();
property.StatusCode = HttpStatusCode.OK;
reply.Properties[HttpResponseMessageProperty.Name] = property;
}
}
}
}
public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
{
}
public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
foreach (ServiceEndpoint endpoint in serviceDescription.Endpoints)
{
endpoint.Behaviors.Add(new SilverlightFaultEndpointBehavior());
}
}
public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
}
}
We use our own custom ServiceException class on the server e.g.
[Serializable]
public class ServiceException : Exception
{
public ServiceException()
{
}
public ServiceException(string message, Exception innerException)
: base(message, innerException)
{
}
public ServiceException(Exception innerException)
: base("Service Exception Occurred", innerException)
{
}
public ServiceException(string message)
: base(message)
{
}
}
And then in our server side service methods we use error handling like this:
try
{
......
}
catch (Exception ex)
{
Logger.GetLog(Logger.ServiceLog).Error("MyErrorMessage", ex);
throw new ServiceException("MyErrorMessage", ex);
}
We then use a generic method for all web service calls:
/// <summary>
/// Runs the given functon in a try catch block to wrap service exception.
/// Returns the result of the function.
/// </summary>
/// <param name="action">function to run</param>
/// <typeparam name="T">Return type of the function.</typeparam>
/// <returns>The result of the function</returns>
protected T Run<T>(Func<T> action)
{
try
{
return action();
}
catch (ServiceException ex)
{
ServiceLogger.Error(ex);
throw new FaultException(ex.Message, new FaultCode("ServiceError"));
}
catch (Exception ex)
{
ServiceLogger.Error(ex);
throw new FaultException(GenericErrorMessage, new FaultCode("ServiceError"));
}
}
I am using PRISM 4 and got my head around almost all features, however as soon as I would like to inject my DomainContext class (RIA) into my view model, the hell breaks loose. :) It would be great if an experienced Unity/Prism developer could give me an advice how to proceed.
Within my bootstrapper, I am registering the required class in Unity Container like this:
protected override void ConfigureContainer()
{
base.ConfigureContainer();
Container.RegisterType<SCMDomainContext>();
}
Within the NavigationModule, I have the following in the ctor to register the NavigationView with a particular region.
public NavigationModule(IUnityContainer container, IRegionManager regionManager)
{
_container = container;
_regionManager = regionManager;
_regionManager.RegisterViewWithRegion(Constants.NavRegion, () => _container.Resolve<NavigationView>());
}
The View takes the View Model as dependency:
public NavigationView(NavigationViewModel viewModel)
{
InitializeComponent();
Loaded += (s, e) =>
{
DataContext = viewModel;
};
}
The ViewModel has the following:
public NavigationViewModel(SCMDomainContext context)
{
_context = context;
ConstructCommon();
}
As soon as I comment this ctor out and put a en empty ctor, it is all fine, for some reason I can't resolve the SCMDomainContext class. Which is the one you add to have the Domain Context created for you provided by Ria Services.
Since I am using Silverlight, I can't see the stack trace to follow the exception, all I get is this message on a page. What am I missing please?
Microsoft JScript runtime error: Unhandled Error in Silverlight Application An exception occurred while initializing module 'NavigationModule'.
- The exception message was: Activation error occured while trying to get instance of type NavigationModule, key ''
Check the InnerException property of the exception for more information. If the exception occurred
while creating an object in a DI container, you can exception.GetRootException() to help locate the
root cause of the problem. at Microsoft.Practices.Prism.Modularity.ModuleInitializer.HandleModuleInitializationError(ModuleInfo moduleInfo, String assemblyName, Exception exception)
at Microsoft.Practices.Prism.Modularity.ModuleInitializer.Initialize(ModuleInfo moduleInfo)
at Microsoft.Practices.Prism.Modularity.ModuleManager.LoadModulesThatAreReadyForLoad()
at Microsoft.Practices.Prism.Modularity.ModuleManager.IModuleTypeLoader_LoadModuleCompleted(Object sender, LoadModuleCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.RaiseLoadModuleCompleted(LoadModuleCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.HandleModuleDownloaded(DownloadCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.IFileDownloader_DownloadCompleted(Object sender, DownloadCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.FileDownloader.WebClient_OpenReadCompleted(Object sender, OpenReadCompletedEventArgs e)
at System.Net.WebClient.OnOpenReadCompleted(OpenReadCompletedEventArgs e)
at System.Net.WebClient.OpenReadOperationCompleted(Object arg)
Your help on this is highly appreciated,
Kave
I can't see much wrong here. But having said that, I'm using the Initialize method from the interface in the following way to register types and views for regions:
#region properties
[Dependency]
public IUnityContainer Container { get; set; }
[Dependency]
public IRegionManager RegionManager { get; set; }
#endregion
public virtual void Initialize()
{
this.Container.RegisterType<NavigationViewModel>(new ContainerControlledLifetimeManager());
this.Container.RegisterType<NavigationView>(new ContainerControlledLifetimeManager());
this.RegionManager.RegisterViewWithRegion(Constants.NavRegion, () => this.Container.Resolve<NavigationView>());
}
Not sure whether it makes a difference if you don't explicitly register the ViewModel and the View type. Personally I prefer to have control over the way how a type gets resolved by the container.
In fact its best to create a layer for the DomainContext like this. Then its easily resolvable by an IoC:
public class ContactModuleService : IContactModuleService
{
readonly SCMDomainContext _context = new SCMDomainContext();
#region Implementation of IContactModuleService
public EntitySet<Contact> Contacts
{
get { return _context.Contacts; }
}
public EntityQuery<Contact> GetContactsQuery()
{
return _context.GetContactsQuery();
}
public SubmitOperation SubmitChanges(Action<SubmitOperation> callback, object userState)
{
return _context.SubmitChanges(callback, userState);
}
public SubmitOperation SubmitChanges()
{
return _context.SubmitChanges();
}
public LoadOperation<TEntity> Load<TEntity>(EntityQuery<TEntity> query, Action<LoadOperation<TEntity>> callback, object userState) where TEntity : Entity
{
return _context.Load(query, callback, userState);
}
public LoadOperation<TEntity> Load<TEntity>(EntityQuery<TEntity> query) where TEntity : Entity
{
return _context.Load(query);
}
#endregion
}
Hi I try implement solution from this site im my WPF app for global exception handling.
http://www.codeproject.com/Articles/90866/Unhandled-Exception-Handler-For-WPF-Applications.aspx
I use Caliburn Micro as MVVM framework. Service I have in external assembly and it is injected in view model class with MEF.
Here is my implementation for global exception handling in WPF app.
App.xaml
DispatcherUnhandledException="Application_DispatcherUnhandledException"
Startup="Application_Startup"
App class:
public partial class App : Application
{
private IMessageBox _msgBox = new MessageBoxes.MessageBoxes();
public bool DoHandle { get; set; }
private void Application_Startup(object sender, StartupEventArgs e)
{
AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
}
private void Application_DispatcherUnhandledException(object sender,
System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e)
{
if (DoHandle)
{
_msgBox.ShowException(e.Exception);
e.Handled = true;
}
else
{
_msgBox.ShowException(e.Exception);
e.Handled = false;
}
}
void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
var ex = e.ExceptionObject as Exception;
_msgBox.ShowException(ex);
}
}
Service method from external assembly:
public void ServiceLogOn()
{
try
{
}
catch (Exception ex)
{
throw ex;
}
}
This service method is call in view model class for example on button click event:
[Export(typeof(ILogOnViewModel))]
public class LogOnViewModel : Screen, ILogOnViewModel
{
public void LogOn()
{
_service.ServiceLogOn();
}
}
I run WPF app in Visual Studio and produce exception with message "Bad credentials" in ServiceLogOn method.
I expect that I see the message box with the exception.
But Visual Studio stop debuging app and show exception in service method in service project.
So I try run WPF from exe file and produce same exception in ServiceLogOn method.
I get this error:
Exception has been throw by target of an invocation.
Any exception from view model class is not handled in methods:
Application_DispatcherUnhandledException
or CurrentDomain_UnhandledException.
in App class.
What I do bad?
EDITED with Simon Fox’s answer.
I try implement in MEF bootstraper advice of Simon Fox’s, but I still something do wrong.
I move handle logic for exception to OnUnhandledException method in bootstraper class.
Here is my code from bootstraper class:
public class MefBootStrapper : Bootstrapper<IShellViewModel>
{
//...
private IMessageBox _msgBox = new MessageBoxes.MessageBoxes();
public bool DoHandle { get; set; }
protected override void OnUnhandledException(object sender, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e)
{
if (DoHandle)
{
_msgBox.ShowException(e.Exception);
e.Handled = true;
}
else
{
_msgBox.ShowException(e.Exception);
e.Handled = false;
}
}
//...
}
I bind some method from view model on button and throw new exception. Something like this:
public void LogOn()
{
throw new ArgumentException("Bad argument");
}
But result is sam, I test app out of Visual Studio and get this exception.
Exception has been throw by target of an invocation.
Caliburn.Micro has built in support for hooking unhandled exceptions. The Bootstrapper class (which every Caliburn project requires) sets this up for you and provides the virtual OnUnhandledException method.
In your custom BootStrapper you must override OnUnhandledException to perform any custom actions for unhandled exceptions in your app. Note that you will most likely have to marshal actions such as displaying a message box to the UI thread (Caliburn enables this easily via Execute.OnUIThread).
You may also have an issue in the way your service moves exceptions to the client, but without any details of how the service is implemented/hosted/etc I cannot help. Are you using WCF to do SOAP? Are you using FaultContracts?