/// <summary>
/// Binds the specified collection of attributes.
/// </summary>
/// <typeparam name="TValue">The type to bind to.</typeparam>
/// <param name="attributes">The collection of attributes to bind. The first attribute in the
/// collection should be the primary attribute.</param>
/// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
/// <returns></returns>
public virtual async Task <TValue> BindAsync <TValue>(Attribute[] attributes, CancellationToken cancellationToken = default(CancellationToken))
{
var attribute = attributes.First();
var additionalAttributes = attributes.Skip(1).ToArray();
IBinding binding = await _bindingSource.BindAsync <TValue>(attribute, additionalAttributes, cancellationToken);
if (binding == null)
{
throw new InvalidOperationException("No binding found for attribute '" + attribute.GetType() + "'.");
}
// Create a clone of the binding context, so any binding data that was added
// will be applied to the binding
var ambientBindingContext = new AmbientBindingContext(_bindingSource.AmbientBindingContext.FunctionContext, _bindingData);
var bindingContext = new BindingContext(ambientBindingContext, cancellationToken);
IValueProvider provider = await binding.BindAsync(bindingContext);
if (provider == null)
{
return(default(TValue));
}
Debug.Assert(provider.Type == typeof(TValue));
ParameterDescriptor parameterDesciptor = binding.ToParameterDescriptor();
parameterDesciptor.Name = null; // Remove the dummy name "?" used for runtime binding.
// Add even if watchable is null to show parameter descriptor in status.
string value = provider.ToInvokeString();
IWatchable watchable = provider as IWatchable;
_watcher.Add(parameterDesciptor, value, watchable);
IValueBinder binder = provider as IValueBinder;
if (binder != null)
{
_binders.Add(binder);
}
IDisposable disposableProvider = provider as IDisposable;
if (disposableProvider != null)
{
_disposable.Add(disposableProvider);
}
object result = await provider.GetValueAsync();
return((TValue)result);
}
public async Task <TValue> BindAsync <TValue>(Attribute attribute, CancellationToken cancellationToken)
{
IBinding binding = await _bindingSource.BindAsync <TValue>(attribute, cancellationToken);
if (binding == null)
{
throw new InvalidOperationException("No binding found for attribute '" + attribute.GetType() + "'.");
}
IValueProvider provider = await binding.BindAsync(new BindingContext(
_bindingSource.AmbientBindingContext, cancellationToken));
if (provider == null)
{
return(default(TValue));
}
Debug.Assert(provider.Type == typeof(TValue));
ParameterDescriptor parameterDesciptor = binding.ToParameterDescriptor();
parameterDesciptor.Name = null; // Remove the dummy name "?" used for runtime binding.
string value = provider.ToInvokeString();
IWatchable watchable = provider as IWatchable;
// Add even if watchable is null to show parameter descriptor in status.
_watcher.Add(parameterDesciptor, value, watchable);
IValueBinder binder = provider as IValueBinder;
if (binder != null)
{
_binders.Add(binder);
}
IDisposable disposableProvider = provider as IDisposable;
if (disposableProvider != null)
{
_disposable.Add(disposableProvider);
}
return((TValue)provider.GetValue());
}
private async Task <IValueProvider> WrapAsync(IValueProvider result, ValueBindingContext context)
{
var obj = await result.GetValueAsync();
if (obj is TraceWriter trace)
{
var shortName = context.FunctionContext.MethodName;
FunctionDescriptor descr = _parent._funcLookup(shortName);
var functionLogger = descr.Invoker.FunctionLogger;
// This is the critical call
trace = functionLogger.CreateUserTraceWriter(trace);
return(new SimpleValueProvider(typeof(TraceWriter), trace, result.ToInvokeString()));
}
return(result);
}