Fixes circular dependency when filtering

scripts/lua/modules/alert_category_utils.lua

@@ -0,0 +1,44 @@
+--
+-- (C) 2019-24 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+-- This is just a struct, try to keep this file without requires except for structs
+local alert_categories = require "alert_categories"
+local alert_category_utils = {}
+
+-- ##############################################
+
+-- @brief Given a category found in a user script, this method checks whether the category is valid
+-- and, if not valid, it assigns to the script a default category
+function alert_category_utils.checkCategory(category)
+   if not category or not category["id"] then
+      return alert_categories.other
+   end
+
+   for cat_k, cat_v in pairs(alert_categories) do
+      if category["id"] == cat_v["id"] then
+	 return cat_v
+      end
+   end
+
+   return alert_categories.other
+end
+
+-- ##############################################
+
+function alert_category_utils.getCategoryById(id)
+   for cat_k, cat_v in pairs(alert_categories) do
+      if cat_v["id"] == id then
+	 return cat_v
+      end
+   end
+
+   return alert_categories.other
+end
+
+-- ##############################################
+
+return alert_category_utils