Added mapping support for derived collections

JeremyCaney · JeremyCaney · commit 560aacab40fe · 2021-01-12T16:53:21.000-08:00
Previously, the collection support of the `TopicMappingService` expected that the collection would be generic, and that's where it would determine the compatible list type.

That works fine if, in fact, the collection type _is_ generic. It fails, however, if the class derives from a generic type. In that case, instead, we need to loop through the available interfaces, identify the `IList&lt;T&gt;` interface, and then get the generic type from _that_ interface, since we won't be able to get it off the actual non-generic type.

This implements that support.
diff --git a/OnTopic/Mapping/TopicMappingService.cs b/OnTopic/Mapping/TopicMappingService.cs
@@ -635,9 +635,11 @@ MappedTopicCache          cache
       | Determine the type of item in the list
       \-----------------------------------------------------------------------------------------------------------------------*/
       var listType = typeof(ITopicViewModel);
-      if (configuration.Property.PropertyType.IsGenericType) {
-        //Uses last argument in case it's a KeyedCollection; in that case, we want the TItem type
-        listType = configuration.Property.PropertyType.GetGenericArguments().Last();
+      foreach (var type in configuration.Property.PropertyType.GetInterfaces()) {
+        if (type.IsGenericType && typeof(IList<>) == type.GetGenericTypeDefinition()) {
+          //Uses last argument in case it's a KeyedCollection; in that case, we want the TItem type
+          listType = type.GetGenericArguments().Last();
+        }
       }
 
       /*------------------------------------------------------------------------------------------------------------------------
