implement registration

common/models/EventType.php

@@ -76,4 +76,20 @@ class EventType extends \yii\db\ActiveRecord
         }
         return ArrayHelper::merge($extra,$items);
     }
+
+    /**
+     * Find the first ticket, which allows this event type
+     * @param \common\models\Ticket[] $tickets the list of active tickets
+     * @return Ticket|null
+     */
+    public function findTicketAllowingEventType($tickets){
+        if  (!isset($tickets)){
+            return null;
+        }
+        if ( sizeof($tickets) == 0 ){
+            return null;
+        }
+        // TODO: implement bossiness logic to select ticket
+        return $tickets[0];
+    }
 }