/// <summary>
/// When implemented in a derived class, returns an object that is provided as the value of the target property for this markup extension.
/// </summary>
/// <param name="serviceProvider">A service provider helper that can provide services for the markup extension.</param>
/// <returns>The object value to set on the property where the extension is applied.</returns>
public override object ProvideValue(IServiceProvider serviceProvider)
{
if (this.Method == null)
throw new InvalidOperationException("Method has not been set");
var valueService = (IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget));
// Seems this is the case when we're in a template. We'll get called again properly in a second.
// http://social.msdn.microsoft.com/Forums/vstudio/en-US/a9ead3d5-a4e4-4f9c-b507-b7a7d530c6a9/gaining-access-to-target-object-instead-of-shareddp-in-custom-markupextensions-providevalue-method?forum=wpf
if (!(valueService.TargetObject is DependencyObject))
return this;
var targetObject = (DependencyObject)valueService.TargetObject;
var rootObjectProvider = (IRootObjectProvider)serviceProvider.GetService(typeof(IRootObjectProvider));
var rootObject = rootObjectProvider == null ? null : rootObjectProvider.RootObject as DependencyObject;
var propertyAsDependencyProperty = valueService.TargetProperty as DependencyProperty;
if (propertyAsDependencyProperty != null && propertyAsDependencyProperty.PropertyType == typeof(ICommand))
{
// If they're in design mode and haven't set View.ActionTarget, default to looking sensible
return new CommandAction(targetObject, rootObject, this.Method, this.CommandNullTargetBehaviour, this.CommandActionNotFoundBehaviour);
}
var propertyAsEventInfo = valueService.TargetProperty as EventInfo;
if (propertyAsEventInfo != null)
{
var ec = new EventAction(targetObject, rootObject, propertyAsEventInfo.EventHandlerType, this.Method, this.EventNullTargetBehaviour, this.EventActionNotFoundBehaviour);
return ec.GetDelegate();
}
// For attached events
var propertyAsMethodInfo = valueService.TargetProperty as MethodInfo;
if (propertyAsMethodInfo != null)
{
var parameters = propertyAsMethodInfo.GetParameters();
if (parameters.Length == 2 && typeof(Delegate).IsAssignableFrom(parameters[1].ParameterType))
{
var ec = new EventAction(targetObject, rootObject, parameters[1].ParameterType, this.Method, this.EventNullTargetBehaviour, this.EventActionNotFoundBehaviour);
return ec.GetDelegate();
}
}
throw new ArgumentException("Can only use ActionExtension with a Command property or an event handler");
}
public void DoesNotRetainTarget()
{
var view = new DependencyObject();
var weakView = new WeakReference(view);
View.SetActionTarget(view, this.target);
var cmd = new EventAction(view, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Throw, ActionUnavailableBehaviour.Throw);
cmd = null;
view = null;
GC.Collect();
Assert.IsFalse(weakView.IsAlive);
}
public void OperatesAfterCollection()
{
var view = new DependencyObject();
var cmd = new EventAction(view, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Throw, ActionUnavailableBehaviour.Throw);
GC.Collect();
View.SetActionTarget(view, this.target);
cmd.GetDelegate().DynamicInvoke(null, null);
Assert.IsTrue(this.target.DoSomethingCalled);
}
public void PropagatesActionException()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomethingUnsuccessfully", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
var e = Assert.Throws<TargetInvocationException>(() => cmd.GetDelegate().DynamicInvoke(null, null));
Assert.IsInstanceOf<InvalidOperationException>(e.InnerException);
Assert.AreEqual("foo", e.InnerException.Message);
}
public void ExecuteThrowsIfActionTargetIsDefault()
{
View.SetActionTarget(this.subject, View.InitialActionTarget);
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Throw, ActionUnavailableBehaviour.Throw);
var e = Assert.Throws<TargetInvocationException>(() => cmd.GetDelegate().DynamicInvoke(null, null));
Assert.IsInstanceOf<ActionNotSetException>(e.InnerException);
}
public void InvokingCommandCallsMethodWithSenderAndDependencyChangedEventArgs()
{
var cmd = new EventAction(this.subject, null, this.dependencyChangedEventInfo.EventHandlerType, "DoSomethingWithObjectAndDependencyChangedEventArgs", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
var sender = new object();
var arg = new DependencyPropertyChangedEventArgs();
cmd.GetDelegate().DynamicInvoke(sender, arg);
Assert.AreEqual(sender, this.target.Sender);
Assert.AreEqual(arg, this.target.DependencyChangedEventArgs);
}
public void BadEventHandlerSignatureThrows()
{
var cmd = new EventAction(this.subject, null, typeof(Subject).GetEvent("BadEventHandler").EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
Assert.Throws<ActionEventSignatureInvalidException>(() => cmd.GetDelegate());
}
public void InvokingCommandCallsMethodWithEventArgs()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomethingWithEventArgs", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
var arg = new RoutedEventArgs();
cmd.GetDelegate().DynamicInvoke(null, arg);
Assert.AreEqual(arg, this.target.EventArgs);
}
public void InvokingCommandCallsMethod()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
cmd.GetDelegate().DynamicInvoke(null, null);
Assert.True(this.target.DoSomethingCalled);
}
public void InvokingCommandDoesNothingIfActionIsNonExistent()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Enable);
View.SetActionTarget(this.subject, new Target2());
cmd.GetDelegate().DynamicInvoke(null, null);
}
public void ThrowsWhenClickedIfActionNonExistentBehaviourIsThrowAndActionIsNonExistent()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Enable, ActionUnavailableBehaviour.Throw);
Assert.DoesNotThrow(() => View.SetActionTarget(this.subject, new Target2()));
var e = Assert.Throws<TargetInvocationException>(() => cmd.GetDelegate().DynamicInvoke(null, new RoutedEventArgs()));
Assert.IsInstanceOf<ActionNotFoundException>(e.InnerException);
}
public void ThrowsIfTargetNullBehaviourIsThrowAndTargetBecomesNull()
{
var cmd = new EventAction(this.subject, null, this.eventInfo.EventHandlerType, "DoSomething", ActionUnavailableBehaviour.Throw, ActionUnavailableBehaviour.Enable);
Assert.Throws<ActionTargetNullException>(() => View.SetActionTarget(this.subject, null));
}
