private static void ResolveScopedOverrideFilter(
FilterContext filterContext,
FilterScope scope,
AutofacFilterCategory filterCategory,
ILifetimeScope lifeTimeScope,
HttpActionDescriptor descriptor)
{
var filters = filterContext.LifetimeScope.Resolve <IEnumerable <Meta <IOverrideFilter> > >();
foreach (var filter in filters)
{
var metadata = filter.Metadata.TryGetValue(FilterMetadataKey, out var metadataAsObject)
? metadataAsObject as FilterMetadata
: null;
if (metadata != null)
{
foreach (var filterRegistration in metadata.PredicateSet)
{
if (FilterMatchesAndNotAlreadyAdded(filterContext, scope, filterCategory, lifeTimeScope, filterRegistration, descriptor))
{
filterContext.Filters.Add(new FilterInfo(filter.Value, scope));
filterContext.AddedFilters[filterCategory].Add(filterRegistration);
}
}
}
}
}
private static bool MatchingFilterAlreadyAdded(FilterContext filterContext, AutofacFilterCategory filterCategory, ILifetimeScope lifeTimeScope, HttpActionDescriptor descriptor, FilterPredicateMetadata metadata)
{
var filters = filterContext.AddedFilters[filterCategory];
return(filters.Any(filter => filter.Scope == metadata.Scope &&
filter.Predicate(lifeTimeScope, descriptor)));
}
private static void ResolveScopedFilter <TFilter, TWrapper>(
FilterContext filterContext,
FilterScope scope,
ILifetimeScope lifeTimeScope,
HttpActionDescriptor descriptor,
Func <HashSet <FilterMetadata>, TWrapper> wrapperFactory,
AutofacFilterCategory filterCategory)
where TFilter : class
where TWrapper : class, IFilter
{
var filters = filterContext.LifetimeScope.Resolve <IEnumerable <Meta <Lazy <TFilter> > > >();
// We'll store the unique filter registrations here until we create the wrapper.
HashSet <FilterMetadata> metadataSet = null;
foreach (var filter in filters)
{
var metadata = filter.Metadata.TryGetValue(FilterMetadataKey, out var metadataAsObject)
? metadataAsObject as FilterMetadata
: null;
// Match the filter category (action filter, authentication, the overrides, etc).
if (metadata != null)
{
// Each individual predicate of the filter 'could' match the action descriptor.
// The HashSet makes sure the same filter doesn't go in twice.
foreach (var filterRegistration in metadata.PredicateSet)
{
if (FilterMatches(scope, filterCategory, lifeTimeScope, descriptor, filterRegistration))
{
if (metadataSet == null)
{
// Don't define a hash set if something has already been registered (should just be the IOverrideFilters).
if (!MatchingFilterAlreadyAdded(filterContext, filterCategory, lifeTimeScope, descriptor, filterRegistration))
{
metadataSet = new HashSet <FilterMetadata>
{
metadata,
};
filterContext.AddedFilters[filterCategory].Add(filterRegistration);
}
}
else
{
metadataSet.Add(metadata);
}
}
}
}
}
if (metadataSet != null)
{
// Declare our wrapper (telling it which filters it is responsible for)
var wrapper = wrapperFactory(metadataSet);
filterContext.Filters.Add(new FilterInfo(wrapper, scope));
}
}
private static bool FilterMatchesAndNotAlreadyAdded(
FilterContext filterContext,
FilterScope scope,
AutofacFilterCategory filterCategory,
ILifetimeScope lifeTimeScope,
FilterPredicateMetadata metadata,
HttpActionDescriptor descriptor)
{
return(FilterMatches(scope, filterCategory, lifeTimeScope, descriptor, metadata) &&
!MatchingFilterAlreadyAdded(filterContext, filterCategory, lifeTimeScope, descriptor, metadata));
}
private static bool FilterMatches(
FilterScope scope,
AutofacFilterCategory filterCategory,
ILifetimeScope lifeTimeScope,
HttpActionDescriptor descriptor,
FilterPredicateMetadata metadata)
{
return(metadata.FilterCategory == filterCategory &&
metadata.Scope == scope &&
metadata.Predicate(lifeTimeScope, descriptor));
}
