address fields differently

app/graphql/types/event_data_edge.rb

@@ -10,29 +10,29 @@ class EventDataEdge < GraphQL::Relay::Edge
 
   def event_data
     @event_data ||= begin
-      Event.query(nil, subj_id: self.node[:id], obj_id: self.parent[:id]).results.first.to_h
+      Event.query(nil, subj_id: self.node.id, obj_id: self.parent.id).results.first.to_h
     end
   end
 
   def source_id
-    self.node[:id]
+    self.node.id
   end
 
   def target_id
-    self.parent[:id]
+    self.parent.id
   end
 
   def source
-    event_data[:source_id].underscore.camelcase(:lower)
+    event_data.source_id.underscore.camelcase(:lower)
   end
 
   # We are switching subj and obj, and thus need to change direction of relation type
   def relation_type
-    rt = event_data[:relation_type_id].underscore.camelcase(:lower)
+    rt = event_data.relation_type_id.underscore.camelcase(:lower)
     RELATION_TYPES.fetch(rt, rt) 
   end
 
   def total
-    event_data[:total]
+    event_data.total
   end
 end

app/graphql/types/event_data_edge_type.rb

@@ -3,9 +3,9 @@
 class EventDataEdgeType < GraphQL::Types::Relay::BaseEdge
   node_type(EventDataType)
 
-  field :source_id, String, null: false, description: "The source ID of the event."
-  field :target_id, String, null: false, description: "The target ID of the event."
-  field :source, String, null: false, description: "Source for this event"
-  field :relation_type, String, null: false, description: "Relation type for this event."
-  field :total, Integer, null: false, description: "Total count for this event."
+  field :source_id, String, null: true, description: "The source ID of the event."
+  field :target_id, String, null: true, description: "The target ID of the event."
+  field :source, String, null: true, description: "Source for this event"
+  field :relation_type, String, null: true, description: "Relation type for this event."
+  field :total, Integer, null: true, description: "Total count for this event."
 end