WIP

Sources/DataStack+Querying.swift

@@ -46,6 +46,19 @@ extension DataStack: FetchableSource, QueryableSource {
         return self.mainContext.fetchExisting(object)
     }
     
+    /**
+     Fetches the `DynamicObject` instance in the `DataStack`'s context from an `NSManagedObjectID`.
+     
+     - parameter persistentID: the `DynamicObjectID` for the object
+     - returns: the `DynamicObject` instance if the object exists in the `DataStack`, or `nil` if not found.
+     */
+    public func fetchExisting<O: DynamicObject>(
+        _ persistentID: DynamicObjectID<O>
+    ) -> O? {
+
+        return self.mainContext.fetchExisting(persistentID.managedObjectID)
+    }
+    
     /**
      Fetches the `DynamicObject` instance in the `DataStack`'s context from an `NSManagedObjectID`.
      
@@ -72,6 +85,19 @@ extension DataStack: FetchableSource, QueryableSource {
         return self.mainContext.fetchExisting(objects)
     }
     
+    /**
+     Fetches the `DynamicObject` instances in the `DataStack`'s context from a list of `DynamicObjectID`.
+     
+     - parameter objectIDs: the `DynamicObjectID` array for the objects
+     - returns: the `DynamicObject` array for objects that exists in the `DataStack`
+     */
+    public func fetchExisting<O: DynamicObject, S: Sequence>(
+        _ objectIDs: S
+    ) -> [O] where S.Iterator.Element == DynamicObjectID<O> {
+
+        return self.mainContext.fetchExisting(objectIDs)
+    }
+    
     /**
      Fetches the `DynamicObject` instances in the `DataStack`'s context from a list of `NSManagedObjectID`.