public Task <IBinding> TryCreateAsync(BindingProviderContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
// Determine whether we should bind to the current parameter
ParameterInfo parameter = context.Parameter;
ProjectionAttribute attribute = parameter.GetCustomAttribute <ProjectionAttribute>(inherit: false);
if (attribute == null)
{
return(Task.FromResult <IBinding>(null));
}
// What data type(s) can this attribute be attached to?
IEnumerable <Type> supportedTypes = new Type[] { typeof(Projection) };
if (!(parameter.ParameterType == typeof(Projection)))
{
throw new InvalidOperationException(
$"Can't bind ProjectionAttribute to type '{parameter.ParameterType}'.");
}
return(Task.FromResult <IBinding>(new ProjectionAttributeBinding(parameter, _eventStreamSettings)));
}
public async Task <object> GetValueAsync()
{
object item = null;
await ValidateParameter(_parameter);
if (null != _parameter)
{
ProjectionAttribute attribute = _parameter.GetCustomAttribute <ProjectionAttribute>(inherit: false);
if (null != attribute)
{
item = new Projection(attribute,
settings: _eventStreamSettings);
}
}
return(item);
}