/// <summary>
/// Unbinds this binding
/// </summary>
public override void Unbind()
{
base.Unbind();
RemoveEvent(DataValueChangedEvent);
InnerBinding.Unbind();
}
public override Task ExecuteBindingAsync(
ModelMetadataProvider metadataProvider,
HttpActionContext actionContext,
CancellationToken cancellationToken
)
{
return(TraceWriter.TraceBeginEndAsync(
actionContext.Request,
TraceCategories.ModelBindingCategory,
TraceLevel.Info,
InnerBinding.GetType().Name,
ExecuteBindingAsyncMethodName,
beginTrace: (tr) =>
{
tr.Message = Error.Format(
SRResources.TraceBeginParameterBind,
InnerBinding.Descriptor.ParameterName
);
},
execute: () =>
InnerBinding.ExecuteBindingAsync(
metadataProvider,
actionContext,
cancellationToken
),
endTrace: (tr) =>
{
string parameterName = InnerBinding.Descriptor.ParameterName;
// Model binding error for this parameter shows the error
if (
!actionContext.ModelState.IsValid &&
actionContext.ModelState.ContainsKey(parameterName)
)
{
tr.Message = Error.Format(
SRResources.TraceModelStateInvalidMessage,
FormattingUtilities.ModelStateToString(actionContext.ModelState)
);
}
else
{
tr.Message = actionContext.ActionArguments.ContainsKey(parameterName)
? Error.Format(
SRResources.TraceEndParameterBind,
parameterName,
FormattingUtilities.ValueToString(
actionContext.ActionArguments[parameterName],
CultureInfo.CurrentCulture
)
)
: Error.Format(SRResources.TraceEndParameterBindNoBind, parameterName);
}
},
errorTrace: null
));
}
/// <summary>
/// Provides a values to be used by the framework to set a given target's object target property binding.
/// </summary>
/// <param name="serviceProvider">Service provider offered by the framework.</param>
/// <returns>A <see cref="Binding"/> for the targeted object and property.</returns>
public override object ProvideValue(IServiceProvider serviceProvider)
{
// Format will be:
// <MyDependencyObject MyProperty={BoundPathBinding PathValueBinding={Binding somePropertyProvider}} />
// Build binding in base:
var result = base.ProvideValue(serviceProvider);
// 'Normal' binding is no path is provided:
if (PathValueBinding == null)
{
initialized = true;
}
// Else try to setup binding from here (else will be redone at init and loading):
else if (result is BindingExpression)
{
// As we won't return it as result to framework, it will be GCed. Keep a copy now:
boundPathBinding = InnerBinding?.Clone();
if (boundPathBinding != null)
{
// Try to init now:
providing_value = true;
Initialize(serviceProvider);
providing_value = false;
// If success, then return bound path binding immediately:
if (initialized)
{
return(boundPathBinding.ProvideValue(serviceProvider));
}
else // Else return empty binding:
{
// Build self binding which will be our "null" value to set:
selfPropertyBinding = BindingHelpers.GetIdentityBinding(TargetProperty);
return(selfPropertyBinding.ProvideValue(serviceProvider)); // and return an empty binding while path is unresolved.
}
}
else
{
initialized = true;
}
}
return(result);
}
/// <summary>
/// Hooks up the late bound events for this object
/// </summary>
protected override void HandleEvent(string handler)
{
switch (handler)
{
case DataValueChangedEvent:
if (dataValueChangedReference == null)
{
dataValueChangedReference = InnerBinding.AddValueChangedHandler(
DataItem,
new EventHandler <EventArgs>(HandleChangedEvent)
);
}
break;
default:
base.HandleEvent(handler);
break;
}
}
/// <summary>
/// Removes the late bound events for this object
/// </summary>
protected override void RemoveEvent(string handler)
{
switch (handler)
{
case DataValueChangedEvent:
if (dataValueChangedReference != null)
{
InnerBinding.RemoveValueChangedHandler(
dataValueChangedReference,
new EventHandler <EventArgs>(HandleChangedEvent)
);
dataValueChangedReference = null;
}
break;
default:
base.RemoveEvent(handler);
break;
}
}
